How to Select a Double Row Ball Slewing Bearing

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In the operation of numerous mechanical devices, the double row ball slewing bearing plays a crucial role, directly influencing the performance, stability, and service life of the equipment. To choose a suitable double row ball slewing bearing, it is necessary to comprehensively consider multiple factors.

What is Double Row Ball Slewing Bearing?

The double row ball slewing bearing is a type of slewing bearing, mainly composed of components such as an inner ring, an outer ring, two rows of steel balls, and spacers. Its unique structure features two rows of steel balls. Compared with single row ball slewing bearings, this design significantly enhances the load – carrying capacity, enabling it to simultaneously withstand large axial forces, radial forces, and overturning moments. It is widely used in various large – scale mechanical equipment, such as port cranes, large – scale excavators, and wind power generation equipment. It can ensure the smooth and flexible rotation of key components of the equipment, and is a key mechanical component for ensuring the normal operation and efficient operation of these devices. It plays an important role in enhancing the performance and reliability of the equipment.

Key Factors in Selecting a Slewing Bearing

The double row ball slewing bearing needs to withstand axial forces, radial forces, and overturning moments. It is necessary to accurately calculate various loads generated during the operation of the equipment and determine the load – carrying capacity requirements of the slewing bearing according to the actual working conditions. For example, when a large – scale crane is lifting heavy objects, the slewing bearing not only has to bear the gravity of the heavy objects (radial force), but also has to cope with the overturning moment generated by the rotation of the boom. If the load – carrying capacity is insufficient, the slewing bearing is prone to premature wear, deformation, or even failure. Excessive load – carrying capacity will increase costs and cause waste of resources. When calculating, relevant formulas in mechanical design manuals can be referred to, and accurate calculations can be carried out by combining parameters such as the equipment’s working class, maximum lifting capacity, and slewing radius.

Accuracy is equally important. Different devices have significantly different accuracy requirements for slewing bearings. Equipment such as precision machine tools and robots require slewing bearings to have extremely high rotational accuracy to ensure the accuracy of processing or operation. For some ordinary construction machinery with relatively low accuracy requirements, such as small loaders, the accuracy requirements are not so strict. The accuracy of slewing bearings mainly includes indicators such as radial run – out, axial run – out, and end – face run – out. When selecting, it is necessary to choose products that meet the corresponding accuracy levels according to the accuracy requirements of the equipment. Generally, the higher the accuracy level, the higher the price. Therefore, it is necessary to reasonably select the accuracy level on the premise of meeting the equipment’s usage requirements.

Speed limits also need to be carefully considered. Each double row ball slewing bearing has its allowable maximum speed. If the actual working speed of the equipment exceeds the limit speed of the slewing bearing, it will lead to increased friction and severe heat generation, thus shortening the service life of the slewing bearing and even causing malfunctions. When selecting, it is necessary to clarify the normal working speed range of the equipment and ensure that the maximum speed of the selected slewing bearing is greater than the working speed of the equipment. At the same time, the impact of speed changes on the slewing bearing, such as the impact during start – up and shutdown, also needs to be considered. For working conditions with high speeds, slewing bearings with good lubrication performance and lightweight rolling elements can be selected.

The size specification is the basis for selection. It is necessary to determine the outer dimensions of the slewing bearing, including the outer diameter, inner diameter, and width, according to the structure and installation space of the equipment. At the same time, details such as the position, size, and number of installation holes also need to be considered to ensure that the slewing bearing can be perfectly adapted to the equipment. If the size is too large or too small, it cannot be installed and used normally. In the design stage, sufficient installation space for the slewing bearing should be fully considered and reserved. When selecting, the size parameters of the product should be carefully checked to avoid installation problems.

The sealing and lubrication conditions are directly related to the service life of the slewing bearing. Good sealing can effectively prevent the intrusion of dust, impurities, and moisture, avoiding the wear and corrosion of the rolling elements and raceways. Common sealing methods include rubber seals and labyrinth seals. The appropriate sealing form should be selected according to the working environment of the equipment. In dusty and humid environments, rubber seals with good sealing performance should be selected and regularly inspected and replaced. In clean and dry environments, labyrinth seals may be sufficient to meet the requirements. In terms of lubrication, it is necessary to ensure that the slewing bearing is well – lubricated to reduce friction and wear. Different types of slewing bearings have different requirements for lubricants. Appropriate lubricants should be selected according to the product instructions and added or replaced regularly.

The material quality determines the performance and reliability of the slewing bearing. Common materials for slewing bearings include high – quality carbon steel and alloy steel. High – quality materials have characteristics such as high strength, high hardness, good wear resistance, and corrosion resistance. When selecting, attention should be paid to the quality of the materials and the heat treatment process. Materials subjected to appropriate heat treatment can further improve their comprehensive performance. For slewing bearings used in harsh working conditions, such as high – temperature, heavy – load, and strong – corrosion environments, special materials or products with surface treatment, such as carburized and quenched alloy steel, should be selected to improve their performance and service life.

The manufacturing process affects the quality and accuracy of the slewing bearing. Advanced manufacturing processes can ensure the dimensional accuracy, surface quality, and assembly quality of the slewing bearing. When selecting, it is necessary to understand the manufacturing process level of the manufacturer, such as the advancement of processing equipment, the standardization of the production process, and the perfection of the quality control system. The manufacturing process can be evaluated by visiting the manufacturer, checking product samples, and understanding user reviews. Products processed by numerical control machine tools, assembled automatically, and strictly quality – tested are more reliable in quality and more stable in performance.

The Price of Double Row Ball Slewing Bearings

There are many factors affecting the price of slewing bearings. Firstly, raw materials. High – quality steel has a high cost, and products made from it have excellent performance and a long service life, so the price is also high. Secondly, slewing bearings with complex manufacturing processes and high – precision requirements require advanced equipment and strict quality control, so the price will also increase accordingly. Moreover, the larger and more special the size and specifications are, the greater the processing difficulty and material consumption, and the higher the price. Brands and manufacturers’ reputations are also crucial. Well – known brands invest a lot in research and development, production, and after – sales service. Their products are of reliable quality, and the prices are also on the high side. Finally, the market supply – and – demand relationship affects the price. When the demand is strong and the supply is tight, the price rises; otherwise, it falls.

Suppliers of Double Row Ball Slewing Bearings

In terms of quality control, ldb bearing company does an excellent job. Every link from the incoming of raw materials to the outgoing of finished products is strictly controlled. Raw materials are multi – dimensionally tested to ensure their quality compliance. During the production process, every processing step is strictly inspected, and detailed records are kept. Before the finished products leave the factory, comprehensive performance tests are carried out, and only products that fully meet the standards can enter the market.

The Development History of Four-Point Contact Slewing Bearings

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The development history of four-point contact slewing bearings is a history of continuous innovation and breakthroughs. It has always kept pace with the development of science and technology and continuously met the growing demands of various industries for mechanical components.

What is Four-Point Contact Slewing Bearing?

The four-point contact slewing bearing is a mechanical component composed of an inner ring, an outer ring, rolling elements, etc. The rolling elements have four-point contact with the raceways of the inner and outer rings, enabling the bearing to withstand axial forces, radial forces, and overturning moments simultaneously. It features a compact structure, high rotational accuracy, and large load-carrying capacity. It is widely used in fields such as construction machinery, wind power, and robotics, and can realize the smooth rotational movement of components. It is an indispensable key component in many large-scale mechanical equipment.

The Impetus of the Industrial Revolution: The Germination of Modern Slewing Bearings

It was the Industrial Revolution in the 18th century that truly promoted the development of slewing bearings. The widespread application of industrial manufacturing and mechanical devices put forward higher requirements for bearing technology. In 1776, the gyroscopic disc-shaped rolling bearing invented by the Scottish engineer John Sgriam was regarded as the prototype of modern slewing bearings. In the early 19th century, the British engineer Robert Jenner further improved the design and invented a metal bearing, making the slewing movement more stable and reliable and promoting the widespread application of slewing bearings in industrial machinery and railway transportation.

The Key Breakthrough in the Early 20th Century: The Birth of Four-Point Contact Slewing Bearings

The early 20th century was an important stage in the development of four-point contact slewing bearings. In 1912, the spherical ball device invented by the British engineer Joseph Thomson laid the foundation for the design of four-point contact slewing bearings. This design enables the bearing to withstand axial loads, radial loads, and tilting moments through the four-point contact between the steel balls and the bearing raceways, greatly expanding the application range of slewing bearings. Since then, four-point contact slewing bearings have continuously improved in design and manufacturing technology. The application of new materials and new technologies has significantly improved their load capacity, wear resistance, and service life.

The Leap in the Mid-20th Century: Material and Process Innovation

In the mid-20th century, with the rapid development of materials science and manufacturing processes, four-point contact slewing bearings迎来了新的突破. The application of new materials such as high-strength alloy steel and ceramic materials has significantly enhanced the performance of slewing bearings. High-strength alloy steel improves the load-carrying capacity and wear resistance of slewing bearings, while ceramic materials endow them with the characteristics of high temperature resistance, corrosion resistance, and low friction, enabling them to operate stably under harsher working conditions. At the same time, the improvement of manufacturing processes, such as the development of precision machining technology and heat treatment technology, has further improved the accuracy and reliability of slewing bearings.

During this period, four-point contact slewing bearings were widely used in fields such as construction machinery, construction machinery, metallurgical machinery, and ship machinery. In construction machinery, such as excavators and cranes, four-point contact slewing bearings enable the working devices to rotate flexibly and efficiently complete various operation tasks; in construction machinery, the slewing mechanism of tower cranes relies on four-point contact slewing bearings to achieve the precise lifting of heavy objects; in metallurgical machinery, the slewing bearings used in equipment such as converters and continuous casters need to withstand huge loads and harsh working environments, and four-point contact slewing bearings ensure the stable operation of the equipment with their excellent performance; in ship machinery, four-point contact slewing bearings provide reliable slewing support for equipment such as ship rudders and cranes.

Modern Innovation and Development: Technology-Driven and Application Expansion

With the continuous progress of science and technology, four-point contact slewing bearings have been continuously innovating in design and manufacturing. The application of technologies such as computer-aided design (CAD) and computer-aided engineering (CAE) enables engineers to design and analyze the structure and performance of slewing bearings more accurately, optimize design schemes, and improve product quality. At the same time, advanced manufacturing equipment and processes, such as numerical control machine tool processing and automated production lines, ensure the high-precision manufacturing and stable production of slewing bearings.

In the application field, four-point contact slewing bearings are constantly expanding new markets. In the wind power generation field, with the growing global demand for clean energy, the installed capacity and single-unit power of wind turbines are constantly increasing, putting forward higher requirements for the load-carrying capacity, reliability, and service life of slewing bearings. Four-point contact slewing bearings have become key components of the yaw and pitch systems of wind turbines with their good performance. In the industrial robot field, with the rapid development of intelligent manufacturing, industrial robots are being used more and more widely. Four-point contact slewing bearings provide high-precision and high-reliability slewing support for the joints of industrial robots, enabling robots to achieve more flexible and precise movements.

The Price of Four-Point Contact Slewing Bearings

There are many factors affecting the price of slewing bearings. Firstly, raw materials. High-quality steel has a high cost, and products made from it have excellent performance and a long service life, so the price is also high. Secondly, slewing bearings with complex manufacturing processes and high precision requirements require advanced equipment and strict quality control, so the price will also increase accordingly. Moreover, the larger and more special the size and specifications are, the greater the processing difficulty and material consumption, and the higher the price.

Suppliers of Four-Point Contact Slewing Bearings

In the field of slewing bearings, ldb bearing company shines globally with its excellent quality and innovation capabilities. With its profound heritage and unremitting efforts, the products of ldb bearing company cover a wide range. Whether they are standard or non-standard slewing bearings, they can be manufactured with high quality to meet the diverse needs of different customers. Advanced production and testing equipment are the cornerstone of high-quality products. ldb bearing company is well aware of this and is equipped with nearly 30 sets of various types of equipment. The company has an experienced design and technical team. With their profound professional knowledge and innovative spirit, they continuously optimize product designs and overcome technical problems.

The Influence of Different Radii on the Performance of Slewing Bearings

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Slewing bearings play a crucial role in numerous mechanical fields. Changes in the radius of a slewing bearing can significantly affect its performance. In different industrial scenarios, the rational selection of the slewing bearing radius is of great importance for the efficient operation, safety, and stability of equipment.

What are Slewing Bearings with Different Radii?

The radius of a slewing bearing has multiple impacts on its performance. In practical applications, factors such as the specific working conditions of the equipment, load-carrying requirements, accuracy requirements, and cost budget need to be comprehensively considered to select a suitable slewing bearing radius. With the continuous progress of science and technology, in the future design and manufacturing of slewing bearings, more attention will be paid to optimizing the matching between the radius and other parameters to further improve the performance of slewing bearings and meet the growing demands of different fields.

Load-Carrying Capacity of Slewing Bearings with Different Radii

The radius of a slewing bearing is closely related to its load-carrying capacity. From the perspective of mechanical principles, slewing bearings with a larger radius have advantages in withstanding axial forces, radial forces, and overturning moments. Take a large crane as an example. Its slewing bearing needs to bear the huge gravity of the boom and the heavy object (generating an axial force), the swing during the hoisting process (generating a radial force), and the overturning moment caused by the eccentricity of the heavy object. When the radius of the slewing bearing increases, the contact area between the raceway and the rolling elements also increases. According to the pressure formula P=\frac{F}{S} (where P is pressure, F is force, and S is the stressed area), under the same load, the increase in the contact area reduces the pressure per unit area. This means that a slewing bearing with a larger radius can more effectively distribute the load without increasing the material strength, thereby improving the load-carrying capacity. Generally, under the same other conditions, if the radius of the slewing bearing is doubled, its load-carrying capacity may increase several times or even more. The specific increase depends on the structural design and material properties of the slewing bearing.

Rotational Accuracy of Slewing Bearings with Different Radii

Rotational accuracy is one of the important indicators for measuring the performance of a slewing bearing, and the radius also has a significant impact on it. When a slewing bearing with a smaller radius is in operation, due to the relatively large influence of the contact accuracy between the rolling elements and the raceway and manufacturing errors, it is prone to generating large rotational errors. However, for a slewing bearing with a larger radius, under the same manufacturing accuracy, the relative error will be reduced. For example, on the turntable of a precision optical instrument, if the radius of the slewing bearing is too small, even if the manufacturing accuracy of the rolling elements and the raceway is very high, small errors may still cause the turntable to shake significantly during rotation, affecting the measurement accuracy of the optical instrument. On the contrary, a slewing bearing with a larger radius can provide a more stable rotational motion, reducing shaking and eccentricity, thereby improving rotational accuracy. Usually, high-precision large slewing bearings, such as those used in astronomical telescopes, have a large radius, and the rotational accuracy can be controlled within a very small range, meeting the requirements of high-precision observations.

Stability of Slewing Bearings with Different Radii

The stability of a slewing bearing is crucial for the safe operation of equipment. Changes in the radius directly affect the stability of the slewing bearing. Slewing bearings with a larger radius usually have a lower center of gravity, which helps to improve the stability of the equipment during operation. Take a wind turbine as an example. Its slewing bearing has a large radius. Under the action of strong winds, the large radius enables the overturning moment generated by the wind to be more effectively dispersed and resisted, reducing the risk of the wind turbine toppling. In addition, slewing bearings with a larger radius also perform better in resisting external impacts and vibrations. When the equipment is disturbed by the outside world, a slewing bearing with a larger radius can, by virtue of its large inertia and structural strength, better maintain stable operation and reduce the possibility of vibration being transmitted to other components of the equipment. However, slewing bearings with a smaller radius, due to their higher center of gravity and relatively compact structure, are more likely to shake and become unstable when facing large external forces.

Friction Resistance of Slewing Bearings with Different Radii

The radius also has a certain impact on the friction resistance of a slewing bearing. During the operation of a slewing bearing, friction resistance is generated between the rolling elements and the raceway. Generally, for slewing bearings with a larger radius, the movement trajectory of the rolling elements is longer. Under the same load and lubrication conditions, the friction resistance will be relatively large. However, with the development of materials science and lubrication technology, the friction resistance can be effectively reduced by using materials with a low friction coefficient and efficient lubrication methods. For example, in the slewing bearings of some large port cranes, although the radius is large, the friction resistance is well controlled through the use of special anti-friction materials and advanced lubrication systems. At the same time, slewing bearings with a larger radius have an advantage in heat dissipation and can better dissipate the heat generated by friction, avoiding problems such as lubrication failure and increased component wear caused by excessive temperature.

Installation Space and Cost of Slewing Bearings with Different Radii

The selection of the slewing bearing radius also needs to consider installation space and cost factors. Slewing bearings with a larger radius usually require more installation space, which may be a limiting factor in some equipment with limited space. For example, in the joints of some small industrial robots, due to the narrow space, only slewing bearings with a smaller radius can be selected. In addition, slewing bearings with a larger radius have higher costs in terms of material usage and manufacturing processes. Manufacturing large slewing bearings requires larger specifications of raw materials and is more difficult to process, thus increasing the manufacturing cost. Therefore, when selecting the slewing bearing radius, factors such as the actual needs of the equipment, installation space, and cost budget need to be comprehensively considered.

Price of Slewing Bearings with Different Radii

The prices of slewing bearings with different radii are affected by multiple factors. In terms of radius size, large-radius slewing bearings are more expensive due to more material usage and difficult processing. Regarding materials, the costs of high-quality alloy steel, stainless steel, etc. vary, which affects the price. The accuracy grade is crucial. High-precision slewing bearings require advanced equipment and strict quality control, and the high cost leads to a high price. Different load-carrying capacities mean that thick plates and large balls are used to meet high-load requirements, which will increase the price. Surface treatments such as chrome plating and other processes increase costs and also cause price differences.

Supplier of Slewing Bearings with Different Radii

Since its establishment, ldb bearing Company has always shone with a unique luster. It is rooted in Luoyang, Henan Province, a fertile ground for the bearing industry. With its professional design and R & D capabilities, it has created many products of excellent quality. The company’s product specifications are rich and diverse. Whether they are standard products or non-standard products, they all demonstrate exquisite craftsmanship. From the entry of raw materials into the factory to the output of finished products, strict process control and quality management are implemented at every step.

Advantages and Disadvantages of Ceramic Slewing Bearings

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In the realm of modern mechanical engineering, slewing bearings are pivotal for the stable operation and performance of equipment. Ceramic slewing bearings, owing to their distinctive material properties, demonstrate certain performance advantages, yet they also have some limitations.

What is Ceramic Slew Bearing?

Ceramic slewing bearings possess remarkable advantages in terms of low mass, high hardness, chemical stability, and high – temperature resistance. These properties hold the potential to enhance the performance of equipment in specific fields. However, drawbacks such as high brittleness, great processing difficulty, and a high elastic modulus restrict their widespread application. With the continuous progress of materials science and processing technology, it is hoped that these shortcomings can be overcome through technological innovation in the future, thereby further expanding the application scope of ceramic slewing bearings.

Advantages of Ceramic Slew Bearing

High Hardness and Wear Resistance,ceramics exhibit extremely high hardness. For example, the hardness of silicon nitride ceramics can reach 2000 – 3000 HV, far exceeding that of ordinary metal materials. This enables minimal wear when used in slewing bearings, even under frequent friction. In production equipment within industries with stringent hygiene requirements, such as food and pharmaceuticals, the high wear resistance of ceramic slewing bearings can minimize the generation of wear particles, preventing product contamination and ensuring product quality and safety. In the rotating parts of textile machinery, the wear – resistant nature of ceramic slewing bearings can decrease equipment maintenance frequency, improve production efficiency, and reduce production costs.

Low Mass ,the density of ceramic materials is significantly lower than that of metals. For example, the density of silicon carbide ceramics is approximately one – third that of steel. In weight – sensitive sectors like aerospace and drones, the adoption of ceramic slewing bearings can substantially reduce the overall weight of the equipment. Take the rotatable components on satellites as an instance. Using ceramic slewing bearings can cut down on fuel consumption, increase the satellite’s payload, and extend its service life. When applied in the gimbal rotation mechanisms of drones, ceramic slewing bearings can enhance flight flexibility and endurance, lower energy costs, and boost economic efficiency.

Good Chemical Stability,ceramic materials feature stable chemical properties and perform outstandingly in corrosive environments like those with acids and alkalis. In fields such as chemical production and offshore engineering, where equipment often comes into contact with corrosive media, ceramic slewing bearings are not as easily corroded as metals. In large – scale rotating feeding equipment for marine aquaculture, ceramic slewing bearings can resist seawater erosion, ensuring the long – term stable operation of the equipment. This reduces the frequency of equipment repair and replacement, safeguarding the continuity of aquaculture operations. In the stirring devices of chemical reaction kettles, using ceramic slewing bearings can prevent equipment failures caused by corrosion, enhancing the safety and stability of chemical production.

Excellent High – Temperature Resistance,Ceramics have prominent high – temperature resistance. Some ceramics, like alumina ceramics, can endure temperatures as high as 1600°C. In high – temperature industrial fields such as metallurgy and glass manufacturing, ceramic slewing bearings can operate normally in harsh high – temperature conditions. In the rotary discharge mechanisms of glass furnaces, ceramic slewing bearings can function stably in the environment of radiant and convective heat from high – temperature glass liquid, ensuring smooth discharge and improving production efficiency. In the tilting mechanisms of metal smelting furnaces, ceramic slewing bearings can withstand the thermal shock of high – temperature molten metal, extending the equipment’s service life and reducing safety risks during the production process.

Disadvantages of Ceramic Slew Bearing

High Brittleness,the brittleness of ceramic materials is one of their major drawbacks. They are prone to cracking when subjected to impact or vibration. In equipment with frequent vibrations and impacts, such as mining machinery and construction equipment, the application of ceramic slewing bearings is limited. For example, the slewing platform of an excavator bears substantial impact forces during operation. If a ceramic slewing bearing is used, it is highly likely to crack and be damaged, affecting the normal operation of the equipment and even potentially causing safety accidents. In the rotating parts of crushers, ceramic slewing bearings struggle to withstand the intense impacts generated during material crushing and cannot meet the actual working requirements.

Great Processing Difficulty,The high hardness and brittleness of ceramic materials make their processing extremely challenging. The processing process necessitates special equipment and techniques, such as grinding with high – precision diamond grinding wheels and laser processing. Moreover, the processing efficiency is low, and the cost is high. Controlling the processing accuracy when manufacturing high – precision ceramic slewing bearing raceways is difficult, resulting in a relatively high rejection rate. This keeps the production cost of ceramic slewing bearings high, restricting their large – scale application. They are only applicable in high – end fields with extremely high – performance requirements and where cost is less of a concern.

High Elastic Modulus,ceramics have a relatively high elastic modulus, meaning they deform minimally under force. Although this can be an advantage in some cases, it becomes a disadvantage in scenarios where buffering and shock absorption are required. In the slewing bearings of precision instruments, the minor vibrations generated during equipment operation are difficult to buffer through the deformation of the ceramic slewing bearings themselves. These vibrations may be transmitted to other components of the instrument, affecting its measurement accuracy. In the steering mechanisms of automotive suspension systems, if ceramic slewing bearings are used, the bumps and vibrations during vehicle travel cannot be effectively buffered. This reduces the ride comfort and may also have an adverse impact on the vehicle’s handling stability.

Price of Ceramic Slew Bearings

The prices of Ceramic Slew Bearings are influenced by multiple factors. Regarding materials, ceramic materials such as silicon nitride and zirconia have high costs, and their preparation processes are intricate. In processing, due to their high hardness and brittleness, high – precision specialized equipment and advanced technologies are needed. This leads to low production efficiency and increased costs. The accuracy grade is also crucial, as high – precision bearings are much more expensive than those of ordinary precision. In terms of brands, well – known brands command higher prices due to their quality and R & D investment. Additionally, market supply and demand relationships can cause price fluctuations.

Supplier of Ceramic Slew Bearings

Since its establishment in Luoyang, Henan Province, Ldb bearing Company has embarked on an extraordinary journey in the bearing industry. Over the years, by focusing on high – precision slewing bearings and slewing drive products, it has been able to precisely produce both standard and non – standard products. Thanks to their excellent quality, these products have become benchmarks of quality and strength within the industry.

Features of Metal Slewing Bearings

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Metal slewing bearings are extensively applied in numerous industrial sectors and serve as crucial components for enabling smooth rotational motion of equipment parts. They possess distinctive structural and performance characteristics, with both prominent advantages and disadvantages.

What is Metal Slewing Bearing?

Metal slewing bearings play an irreplaceable role in various industrial fields, owing to their high load – bearing capacity, high – precision rotation capabilities, reliable stability, and long service life. However, their drawbacks, such as high costs, large weight, and complex installation and maintenance procedures, limit their application in certain scenarios. With the continuous advancement of technology, it is anticipated that in the future, metal slewing bearings will overcome these limitations while maintaining their advantages through means like material innovation and process improvement, thereby achieving broader applications.

Advantages of metal slew bearing

High Load – Bearing Capacity,The structural design of metal slewing bearings allows them to endure diverse types of loads, including axial forces, radial forces, and overturning moments. Take large – scale cranes as an example. When hoisting heavy objects, the slewing bearing has to bear the axial force generated by the combined weight of the boom and the load, the radial force resulting from sway during the hoisting process, and the overturning moment caused by the load’s eccentricity. The raceways and rolling elements of the slewing bearing are crafted from high – strength metal materials and undergo specialized processing techniques, such as surface quenching. This enhances the material’s hardness and wear resistance, ensuring that the slewing bearing can operate stably even under complex stress conditions, boasting a formidable load – bearing capacity. Small – sized metal slewing bearings can have an axial load – bearing capacity of up to several tens of kilonewtons, while large – scale ones can withstand thousands of kilonewtons or even higher axial forces. The slewing bearings of some large – scale port cranes can have an overturning moment – bearing capacity exceeding tens of thousands of newton – meters.

High – Precision Rotation,in precision equipment, the high – precision rotation feature of metal slewing bearings is of utmost importance. For instance, in semiconductor manufacturing equipment, an extremely high level of positioning accuracy for components is required. The manufacturing process of slewing bearings is continuously optimized. The processing accuracy of the raceways can reach the micron level, and the dimensional accuracy and roundness of the rolling elements are strictly controlled. Additionally, the internal structure of the slewing bearing is rationally designed to effectively minimize axial and radial run – out during operation, guaranteeing high – precision positioning of equipment components during rotation. Generally, the rotational accuracy of metal slewing bearings can be maintained within ±5 arc – minutes, and that of high – precision ones can even be controlled within approximately ±1 arc – minute, meeting the high – precision demands of precision equipment.

Reliable Stability,the stability of metal slewing bearings stems from their robust metal structure and excellent sealing design. In harsh industrial environments, such as those with high temperatures, high humidity, or heavy dust, the metal housing of the slewing bearing can effectively resist external impacts and corrosion. The internal sealing device prevents impurities like dust and moisture from infiltrating, protecting the raceways and rolling elements from erosion and ensuring their normal operation. For example, in the large – scale rotary kiln equipment of cement plants, metal slewing bearings can operate stably even when exposed to a dusty environment for an extended period. This reduces equipment malfunctions and boosts production efficiency.

Reliable Stability,the metal materials chosen for metal slewing bearings exhibit good wear resistance and fatigue resistance. Under normal usage and maintenance conditions, they have a relatively long service life. In wind turbines, although the slewing bearings are exposed to complex outdoor weather conditions over an extended period, through rational material selection, regular lubrication, and maintenance, their service life can reach 20 years or even longer. This not only reduces the equipment’s maintenance costs but also extends the overall service cycle of the equipment, minimizing the impact of frequent component replacements on production.

Disadvantages of metal slew bearing

High Costs,the high costs of metal slewing bearings are mainly attributed to materials and processing. To ensure high load – bearing capacity and a long service life, high – quality alloy steels, such as those containing alloying elements like chromium and molybdenum, are typically selected. These materials are expensive. During the processing stage, the high – precision requirements render the processing technology complex. Advanced processing equipment and testing instruments, such as high – precision grinders and coordinate measuring machines, are necessary, driving up the production costs. The price of small – sized metal slewing bearings can range from several thousand yuan, while that of large – scale, high – precision slewing bearings can reach hundreds of thousands of yuan or even higher. This undoubtedly increases the overall manufacturing costs of the equipment.

Large Weight,since metal slewing bearings are predominantly composed of metal materials, they are relatively heavy. In some application scenarios with strict weight constraints, such as the aerospace industry, an overly heavy slewing bearing will increase the overall weight of the aircraft, affecting its flight performance and energy consumption. Even in ground – based equipment, such as small – scale construction machinery that requires frequent movement, an excessively heavy slewing bearing will increase the difficulty of equipment movement and energy consumption, reducing the equipment’s mobility and operational efficiency.

Complex Installation and Maintenance,The installation of metal slewing bearings demands professional skills and equipment, with high – precision installation requirements. During installation, parameters such as the levelness and concentricity of the slewing bearing must meet the specified standards; otherwise, it will affect its normal operation and service life. When installing giant slewing bearings in large – scale bridge construction, large – scale lifting equipment and high – precision measuring instruments are needed. The installation process is complex and time – consuming. Routine maintenance is also rather cumbersome. It is necessary to regularly inspect the lubrication condition and wear level of the slewing bearing, and promptly replenish lubricants and replace worn – out components. The maintenance of some large – scale slewing bearings requires the operation of professional technicians, increasing the maintenance costs and difficulties.

Prices of Metal Slewing Bearings

The prices of metal slewing bearings vary significantly due to multiple factors. Small, ordinary ones may cost a few hundred yuan, such as those used in small – scale machinery with low – precision requirements. Medium – sized ones usually cost around several thousand yuan and are suitable for general industrial equipment. Large – scale, high – precision, or those made of special materials and with unique manufacturing processes can cost tens of thousands of yuan or even more. For example, slewing bearings used in high – end equipment like wind power and offshore engineering. The specific price needs to be determined by comprehensively considering factors such as materials, dimensions, and precision.

Suppliers of Metal Slewing Bearings

Since its establishment, Ldb bearing Company has always stood out with its unique excellence. Rooted in Luoyang, Henan Province, a thriving hub for the bearing industry, the company has leveraged its professional design and R&D capabilities to produce numerous high – quality products. The company offers a wide range of product specifications. Whether they are standard or non – standard products, they all showcase exquisite craftsmanship. From the procurement of raw materials to the production of finished products, strict process control and quality management are implemented at every step.

Effects of Low Temperature on Slewing Bearings

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The effects of low temperature on slewing bearings involve multiple aspects. These effects can seriously threaten the normal operation of equipment. By choosing appropriate solutions, the performance and reliability of slewing bearings in low – temperature environments can be effectively improved.

What is Low – Temperature Slew Bearing?

As a key component for various mechanical equipments to achieve rotational motion between components, slewing bearings are widely used in equipment such as cranes, wind turbines, and tunnel boring machines. In low – temperature environments, the performance and reliability of slewing bearings face many challenges. In – depth understanding of these effects and taking effective solutions are crucial for ensuring the normal operation of equipment and extending its service life.

Effects of Low Temperature on Slewing Bearings

Changes in Material Properties

Low temperature can alter the properties of the metal materials used in slewing bearings. Most metal materials become brittle at low temperatures, with a significant reduction in impact toughness. Taking commonly used bearing steel as an example, in a low – temperature environment, the crystal structure inside the material changes, making it difficult for dislocations to move. This greatly reduces the material’s ability to resist impact loads. When the equipment starts at low temperatures or is impacted during operation, the raceways, rolling elements, and other components of the slewing bearing are more prone to cracks. In severe cases, fractures may even occur, greatly affecting the load – bearing capacity and service life of the slewing bearing.

Decrease in Lubrication Performance

Low temperature seriously affects the lubrication effect of slewing bearings. Lubricating oil increases in viscosity and becomes less fluid at low temperatures, making it difficult to form a good oil film between the raceways and rolling elements. This not only increases the frictional resistance, resulting in increased energy consumption during equipment operation, but also exacerbates the wear between components. Under extremely low – temperature conditions, the lubricating oil may even solidify, completely losing its lubricating function. This causes the wear of the slewing bearing to rise sharply, affecting the rotational accuracy of the equipment and leading to unstable equipment operation, which cannot meet the working requirements.

Deterioration of Sealing Performance

The sealing device of slewing bearings is also affected by low temperatures. Sealing materials usually have a certain elasticity to ensure good sealing performance. However, in a low – temperature environment, the sealing materials harden, become brittle, and their elasticity decreases, resulting in reduced sealing performance. External impurities such as moisture and dust can easily penetrate into the interior of the slewing bearing, contaminating the lubricating oil and accelerating the corrosion and wear of components. If the moisture freezes after entering, it may also damage the sealing structure, further deteriorating the working environment of the slewing bearing.

Changes in Fitting Accuracy Caused by Thermal Expansion and Contraction

Each component of the slewing bearing undergoes dimensional changes due to thermal expansion and contraction at low temperatures. Different materials have different thermal expansion coefficients, which may affect the fitting accuracy between components. For example, the clearance between the raceway and the rolling elements may become smaller, increasing friction and wear. If the clearance is too large, it will affect the rotational accuracy, causing vibration and noise during equipment operation. In addition, thermal expansion and contraction may also cause the connections between the slewing bearing and other equipment components to loosen, affecting the overall stability of the equipment.

Solutions to Cope with the Effects of Low Temperature

Selection of Appropriate Materials

To cope with the low – temperature environment, materials with good low – temperature performance should be selected for manufacturing slewing bearings. For raceways and rolling elements, alloy steels containing elements such as nickel and manganese can be used. These alloying elements can effectively improve the low – temperature toughness of the material and reduce the brittle transition temperature of the material. For slewing bearings used in some extremely cold regions, special low – temperature alloy materials such as nickel – based alloys can also be considered. These materials can still maintain good mechanical properties at low temperatures. For seals, low – temperature – resistant rubber or plastic materials such as fluororubber and silicone rubber should be selected. These materials can maintain good elasticity and sealing performance at low temperatures.

Optimization of the Lubrication System

In response to the problem of reduced lubrication performance at low temperatures, the lubrication system of the slewing bearing needs to be optimized. First, lubricating oil with excellent low – temperature performance should be selected. It has a low pour point and a high viscosity index and can still maintain good fluidity at low temperatures. For example, polyalphaolefin (PAO) lubricating oil in synthetic lubricating oils performs better than mineral lubricating oils in low – temperature environments. Second, heating or heat – preservation devices can be used to increase the temperature of the lubricating oil to ensure its normal flow at low temperatures. In some large – scale equipment, a lubricating oil heating system can be installed to preheat the lubricating oil before the equipment starts. For small – scale equipment, heat – preservation materials can be used to wrap the lubricated parts to reduce heat loss.

Improvement of the Sealing Structure

To improve the sealing performance of slewing bearings at low temperatures, the sealing structure can be improved. A multi – layer sealing design can be adopted to increase the reliability of the seal. For example, multiple sealing lips can be set between the inner and outer rings of the slewing bearing, and sealant can be filled between the sealing lips to prevent the intrusion of external impurities. In addition, the seals should be regularly inspected and replaced to ensure their good performance. In a low – temperature environment, the aging rate of seals accelerates, so more attention needs to be paid to the maintenance of seals.

Compensation for the Effects of Thermal Expansion and Contraction

To compensate for the impact of thermal expansion and contraction on the fitting accuracy of slewing bearings, the thermal expansion coefficients of materials should be fully considered in the design stage, and the fitting clearances between components should be reasonably designed. Methods such as reserving clearances or adjusting shims can be used to ensure the normal fitting between components in a low – temperature environment. During the equipment installation and commissioning process, the fitting clearance of the slewing bearing should be adjusted according to the actual ambient temperature. The fitting accuracy of the slewing bearing can also be regularly detected to timely discover and solve problems caused by thermal expansion and contraction.

Price of Low – Temperature Slew Bearings

The prices of Low – Temperature Slew Bearings are affected by multiple factors. Material is one of the important factors. Special steels that can maintain their performance in low – temperature environments are required, and the high cost leads to an increase in price. The manufacturing process is also crucial. High – precision processing technology and strict quality control ensure the stability and reliability of the bearings at low temperatures, which increases the production cost and leads to a relatively high price. In terms of specifications and dimensions, special – specification or large – size Low – Temperature Slew  Bearings are difficult to produce, and their prices will also increase accordingly.

Supplier of Low – Temperature Slew Bearings

Since its establishment, Ldb bearing Company has always shone with a unique luster. Rooted in Luoyang, Henan Province, a fertile ground for the bearing industry, the company has created many high – quality products with its professional design and R & D capabilities. The company’s product specifications are rich and diverse. Whether they are standard products or non – standard products, they all demonstrate exquisite craftsmanship. From the entry of raw materials into the factory to the output of finished products, strict process control and quality management are implemented at every step.

What kind of Slew bearings can withstand high temperature?

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In the field of modern industry, numerous production processes involve high-temperature environments. In the high-temperature scenarios, ordinary bearings struggle to function properly. Thus, bearings capable of withstanding high temperatures have emerged. These bearings enable equipment to operate stably in high-temperature environments.

What are High-Temperature Slew Bearings?

The primary characteristic of High-Temperature Slew Bearings is their excellent high-temperature resistance. They can maintain structural stability and mechanical properties for extended periods in high-temperature environments. Their materials are usually special alloys, such as alloy steels containing elements like chromium, molybdenum, and vanadium. These alloys can form a dense oxide film at high temperatures, preventing further oxidation and maintaining material strength. For example, at a high temperature of 1000°C, some nickel-based alloy bearing materials can still maintain high hardness and strength, meeting the operational requirements of equipment.

High-Temperature Slew Bearings also require a reliable lubrication system. Ordinary lubricating greases are prone to evaporation and carbonization at high temperatures and cannot provide lubrication. High-Temperature Slew Bearings often use high-temperature-resistant solid lubricants, such as molybdenum disulfide and graphite. These can form a lubricating film at high temperatures, reducing the coefficient of friction. Some High-Temperature Slew Bearings are also equipped with a forced lubrication system, which uses circulating and cooled lubricating oil to dissipate heat and ensure lubrication effectiveness.

Main Types and Characteristics

Ceramic Bearings

Ceramic bearings are outstanding among High-Temperature Slew Bearings. Commonly used ceramic materials include silicon nitride and silicon carbide. These ceramic materials have a low density, approximately one-third that of metals, which can effectively reduce the weight of equipment. They have extremely high hardness, with the hardness of silicon nitride ceramics reaching 2000 – 3000 HV, much higher than that of metals, and excellent wear resistance. In high-temperature environments, ceramic bearings have good chemical stability, are not prone to reacting with other substances, and have strong oxidation resistance. For example, in the high-temperature furnace equipment of the glass manufacturing industry, ceramic bearings can operate stably at around 1500°C, reducing maintenance costs and improving production efficiency. However, ceramic bearings are relatively brittle, prone to damage in impact environments, and have high processing difficulty and costs.

High-Temperature Alloy Bearings

High-temperature alloy bearings use nickel-based and cobalt-based alloys as their main materials. These alloys contain multiple alloying elements such as chromium, molybdenum, and tungsten. They have good oxidation resistance and thermal strength at high temperatures and can withstand high temperatures and heavy loads. Nickel-based alloy bearings can operate normally at 800 – 1000°C and are commonly used in critical components such as aircraft engines and gas turbines. High-temperature alloy bearings have good strength and toughness and can adapt to complex working conditions. However, the alloy composition is complex, resulting in high manufacturing costs.

Self-Lubricating Bearings

Self-lubricating bearings achieve self-lubrication by adding solid lubricants to the metal matrix. Commonly used solid lubricants include molybdenum disulfide and polytetrafluoroethylene. In high-temperature environments, the solid lubricant in this type of bearing can slowly release and form a lubricating film on the friction surface, reducing friction and wear. In the continuous casting equipment of the metallurgical industry, self-lubricating bearings can operate stably in high-temperature, high-load, and difficult-to-lubricate environments, reducing maintenance frequency and improving equipment operation reliability. However, the self-lubricating performance of self-lubricating bearings weakens over time, and lubricants need to be replaced or replenished regularly.

Application Fields

In the aerospace field, parts such as engine combustion chambers and turbines are exposed to extremely high temperatures. The performance of High-Temperature Slew Bearings directly affects the safety and performance of aircraft. For example, High-Temperature Slew Bearings in aircraft engines need to operate at temperatures above 1200°C, withstanding high speeds and heavy loads. Ceramic bearings and high-temperature alloy bearings meet these requirements with their excellent performance, ensuring the stable operation of engines.

In the metallurgical industry, High-Temperature Slew Bearings are widely used in various heating furnaces, rolling mills, and other equipment. During the steel rolling process, the roll bearings need to withstand huge pressure and friction at 500 – 800°C. High-temperature alloy bearings and self-lubricating bearings can adapt to such harsh working conditions, ensuring the continuity of steel rolling production and product quality.

Equipment such as furnaces and annealing furnaces in the glass manufacturing industry also rely on High-Temperature Slew Bearings. In the stirrers and discharge devices of glass furnaces, ceramic bearings can operate stably near high-temperature glass melts at 1400 – 1600°C, preventing metal impurities from contaminating the glass and improving the quality and production efficiency of glass products.

With the continuous development of industrial technology, High-Temperature Slew Bearings also have new application requirements in emerging fields such as new energy and electronic manufacturing. In the concentrator tracking devices of solar thermal power generation systems, High-Temperature Slew Bearings need to operate for long periods in high-temperature and harsh outdoor environments. In high-temperature process equipment for semiconductor manufacturing, High-Temperature Slew Bearings must meet the requirements of high precision and low pollution.

High-Temperature Slew Bearings are indispensable in modern industry. Different types of High-Temperature Slew Bearings have their respective advantages and disadvantages. In practical applications, the appropriate bearing type needs to be selected according to specific working conditions and requirements. With the continuous progress of materials science, manufacturing processes, and lubrication technologies, the performance of High-Temperature Slew Bearings will continue to improve, and their application fields will be further expanded, providing more reliable support for industrial production in high-temperature environments.

Price of High-Temperature Slew Bearings

The price of High-Temperature Slew Bearings are affected by multiple factors. The material is a key factor. High-performance, high-temperature-resistant special alloy materials have high costs, resulting in high prices. In terms of accuracy levels, high-precision High-Temperature Slew Bearings have complex manufacturing processes and are more expensive than ordinary-precision ones. Regarding specifications and dimensions, large-sized or special-specification High-Temperature Slew Bearings are difficult to produce, and their prices will increase accordingly. Market supply and demand relationships also affect prices. When supply is in short supply, prices rise, and when there is an oversupply, prices fall.

Supplier of High-Temperature Slew Bearings

Ldb bearing company has always stood out since its establishment. It is rooted in Luoyang, Henan, a fertile ground for the bearing industry. With its professional design and R&D capabilities, it has created numerous high-quality products. The company offers a wide range of product specifications, and both standard and non-standard products showcase exquisite craftsmanship. From the incoming inspection of raw materials to the output of finished products, strict process control and quality management are implemented at every step.

How to Solve the Failure of Four-Point Contact Slewing Bearings

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There are various methods to deal with the failure of four-point contact slewing bearings. It is essential to strictly control the materials, optimize the processing technology, handle emergencies when fractures occur, analyze the causes for improvement, and ensure the quality and installation accuracy when replacing components.

What is Four-Point Contact Slewing Bearing

The four-point contact slewing bearing is a type of bearing structure. It consists of components such as an inner ring, an outer ring, rolling elements, and a cage. Its uniqueness lies in that the rolling elements have four-point contact with the raceways of the inner and outer rings, enabling it to simultaneously withstand axial forces, radial forces, and tilting moments. This design gives the slewing bearing a high load-carrying capacity and rotational accuracy within a limited space. It is commonly used in construction machinery and large-scale equipment such as cranes, excavators, and wind turbines. It can achieve smooth rotational motion between components, adapt to complex working conditions, and improve the reliability and stability of the equipment.

Different Solutions for Four-Point Contact Slewing Bearings

Wear

– Strengthen Lubrication Management: Strictly follow the equipment’s operation manual to develop a scientific and reasonable lubrication plan. Select appropriate lubricants according to the working environment and operating conditions of the slewing bearing. For example, in high-temperature environments, high-temperature-resistant synthetic grease can be used, and in dusty environments, grease with good sealing and anti-pollution capabilities can be selected. At the same time, ensure that the lubrication frequency and quantity are accurate. Insufficient lubrication cannot effectively reduce friction, while excessive lubrication may cause waste and pollution.

– Precise Installation and Adjustment: When installing the slewing bearing, professional measuring tools and equipment must be used to precisely control the installation accuracy. For example, high-precision theodolites and levels are used to adjust the concentricity and perpendicularity of the slewing bearing, keeping the deviation within the allowable range. During the operation of the equipment, regularly check the installation accuracy and adjust it in a timely manner if there is any deviation to avoid aggravated local wear caused by installation problems.

– Timely Replacement of Worn Components: Establish a perfect wear monitoring mechanism. Evaluate the degree of wear by measuring parameters such as the dimensions and surface roughness of the raceways and steel balls. When the raceway wear exceeds the specified tolerance, or when there are obvious wear marks and dimensional changes on the surface of the steel balls, decisively replace the slewing bearing or relevant worn components. At the same time, when replacing, pay attention to selecting products with reliable quality and matching the original components.

Fatigue Spalling

– Scientific Selection and Design: In the equipment design stage, accurately calculate and analyze the operating conditions of the slewing bearing, such as working load, rotational speed, and operating time. Based on these data, refer to relevant design standards and manuals to reasonably select the model and specifications of the slewing bearing to ensure that it has sufficient load-carrying capacity and fatigue life. In addition, the anti-fatigue performance can be improved by optimizing the design structure, such as increasing the curvature radius of the raceway and improving the quality of the steel balls, to reduce the contact stress.

– Comprehensive Detection and Prevention: Establish a regular comprehensive inspection system. In addition to using non-destructive testing techniques such as magnetic particle inspection and ultrasonic testing to detect fatigue cracks, it is also possible to judge whether there are signs of fatigue spalling by observing the operating state of the slewing bearing, such as abnormal vibration and noise. For the slewing bearings of some key equipment, online monitoring technology can be used to monitor their working conditions in real time and discover potential problems in a timely manner.

– Stable Operation and Maintenance: During the operation of the equipment, try to keep the operating parameters stable and avoid frequent starting, braking, and large-amplitude load changes. At the same time, regularly maintain the slewing bearing, such as cleaning the surfaces of the raceways and steel balls and replenishing lubricants, to reduce the impact of external factors on its fatigue performance.

Plastic Deformation

– Strict Load Control: During the use of the equipment, it is necessary to strictly operate according to the rated load of the slewing bearing and it is strictly prohibited to operate overloaded. In the equipment design stage, reliable overload protection devices such as pressure sensors and limit switches should be installed. When the load exceeds the set value, the equipment will automatically stop running or take corresponding protective measures.

– Optimize the Operation Process: Optimize the starting and braking processes of the equipment through advanced control technologies and equipment to make them more stable. For example, frequency conversion speed regulation technology can be used to achieve soft starting and soft braking of the motor, reducing the impact current and impact force during starting and braking. In addition, buffer devices such as elastic couplings and fluid couplings can be installed in the transmission system of the slewing bearing to further reduce the impact load.

– Deformation Assessment and Repair: Once plastic deformation of the slewing bearing is found, the equipment should be stopped immediately, and a detailed assessment of the deformation should be carried out. Analyze the impact degree of the deformation on the performance of the slewing bearing by measuring parameters such as the size and shape of the deformation. For slight plastic deformation, cold correction or hot correction methods can be used for repair, but strict quality inspection is required after repair. For severe plastic deformation, it is usually necessary to replace the slewing bearing or relevant components.

Corrosion

– Efficient Surface Protection: Effective surface protection treatment of the slewing bearing is a key measure to prevent corrosion. Appropriate surface protection methods can be selected according to different working environments. For general industrial environments, anti-corrosion paint spraying can be used. Select paints with good corrosion resistance and adhesion and construct strictly in accordance with the spraying process requirements. For some harsh corrosive environments, such as humid seashores or chemical workshops, metal plating methods such as galvanizing and chrome plating can be used to improve the corrosion resistance of the slewing bearing.

– Environmental Optimization and Control: Try to improve the working environment of the slewing bearing. Install the equipment in a dry and well-ventilated place to avoid exposure to humid, corrosive gas or liquid environments. For some unavoidable harsh environments, corresponding protective measures can be taken, such as installing dehumidification equipment and ventilation ducts to reduce the humidity and concentration of corrosive media in the environment.

– Regular Maintenance and Treatment: Establish a regular inspection and maintenance system. Regularly check the surface condition of the slewing bearing, and promptly clean the dirt, dust, and corrosion products on the surface. For slightly corroded parts found, methods such as grinding and rust removal can be used for treatment, and then re-protect. For severely corroded parts, timely repair or replacement of components is required to prevent further corrosion expansion.

Fracture

– Strict Material Control: When purchasing a slewing bearing, strictly review the qualifications of the supplier and the material quality certification documents to ensure that the purchased slewing bearing is made of high-quality materials. At the same time, random inspections of the materials can be carried out, such as chemical composition analysis and mechanical property testing, to verify whether the material quality meets the requirements. For important slewing bearings, the supplier can also be required to provide a material flaw detection report to ensure that there are no internal defects in the materials.

– Optimize the Processing Technology: In the processing process of the slewing bearing, optimize each processing technology link, especially the heat treatment process. By reasonably controlling parameters such as heating temperature, holding time, and cooling rate, eliminate processing stress, and improve the uniformity of the material structure and its strength and toughness. In addition, strictly control the surface quality during the processing process to avoid defects such as tool marks and scratches, which may become the origin of fractures.

– Emergency Treatment and Improvement: Once a fracture accident occurs, immediately take emergency measures, stop the equipment operation, set up safety warning signs to prevent the accident from expanding. At the same time, conduct a detailed analysis of the fractured components. Through methods such as fracture surface analysis and material inspection, find out the cause of the fracture. According to the analysis results, take corresponding improvement measures, such as changing materials, improving the processing technology, and optimizing the equipment structure, to prevent similar fracture accidents from occurring again. When replacing the fractured components or the entire slewing bearing, ensure that the quality and installation accuracy of the new components meet the requirements.

Prices of Four-Point Contact Slewing Bearings

Materials are a crucial factor. Using high-quality steel and special alloys can enhance strength and wear resistance. This increases the cost, and thus the price will be higher. For example, slewing drives made of materials containing special alloys are more expensive than those made of ordinary materials. Machining accuracy is also important. High-precision machining requires advanced equipment and technologies, which increases the cost, and as a result, the product price is naturally higher. The slewing drives used in precision equipment generally have high prices. The manufacturing process also affects prices. Advanced processes can optimize performance but also increase costs, thereby raising the selling price.

Suppliers of Four-Point Contact Slewing Bearings

LDB bearing company has risen from obscurity to become well-known in the industry, relying on its dedication to quality and pursuit of innovation. The company is located in Luoyang, Henan Province, where the bearing industry is developed, enjoying the advantages of industrial resources. For example, its self-developed straight-tooth slewing drives have high precision and strong stability, greatly improving the accuracy and efficiency of industrial robots. With high-quality products and attentive services, it has won numerous praises and is bound to create more glories in the future!

What are the failure modes of four – point contact slewing bearings?

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Four – point contact slewing bearings have various failure modes. Each failure mode seriously affects its performance and the operation of the equipment.

What is Four – Point Contact Slewing Bearing

A four – point contact slewing bearing is a type of bearing structure. It consists of components such as an inner ring, an outer ring, rolling elements, and a cage. Its uniqueness lies in that the rolling elements have four – point contact with the raceways of the inner and outer rings, enabling it to simultaneously withstand axial forces, radial forces, and tilting moments. This design gives the slewing bearing a high load – carrying capacity and rotational accuracy within a limited space. It is commonly used in construction machinery and large – scale equipment such as cranes, excavators, and wind turbines. It can achieve smooth rotational motion between components, adapt to complex working conditions, and improve the reliability and stability of the equipment.

Failure Modes of Four – Point Contact Slewing Bearings

Wear

– Raceway Wear: When a four – point contact slewing bearing is in operation, the steel balls continuously roll within the raceways. There is relative motion and contact pressure between them. After long – term operation, the surface of the raceway will gradually wear due to friction. The wear increases the surface roughness of the raceway, making the originally smooth raceway rough. This leads to an increase in the friction force between the steel balls and the raceway, and an increase in energy consumption during operation. At the same time, the dimensional accuracy of the raceway decreases, affecting the rotational accuracy of the slewing bearing and reducing the operating stability of the equipment. For example, in some frequently rotating robotic arms, raceway wear may cause a decrease in the positioning accuracy of the robotic arm, affecting its work quality.

– Cage Wear: The cage is used to separate the steel balls and guide them to roll correctly within the raceways. During the operation of the slewing bearing, there is a certain amount of relative motion and friction between the cage, the steel balls, and the inner and outer rings. If the material of the cage has insufficient wear resistance or the lubrication is poor, wear is likely to occur. After the cage is worn, its guiding and positioning function for the steel balls is weakened. The steel balls may become skewed and collide with each other, further aggravating the wear of the steel balls and the raceway. In severe cases, the steel balls may even come out of the raceway, causing the slewing bearing to fail.

Fatigue Spalling

– Raceway Fatigue Spalling: When a four – point contact slewing bearing is working, the surface of the raceway bears periodic contact stress. Over time, under the action of this alternating stress, the metal material on the surface of the raceway gradually fatigues. Initially, tiny cracks appear at the microscopic level on the surface of the raceway. These cracks will continue to expand as the number of operating cycles increases. When the cracks expand to a certain extent, the metal on the surface of the raceway will spall off, forming fatigue spalling pits. These spalling pits damage the surface integrity of the raceway, deteriorate the contact state between the steel balls and the raceway, cause vibration and noise during the operation of the slewing bearing, reduce the working performance of the equipment, and in severe cases, even affect the load – carrying capacity of the slewing bearing, resulting in the equipment being unable to operate normally.

– Steel Ball Fatigue Spalling: The steel balls also bear cyclic contact stress, and their surfaces are prone to fatigue spalling. Once spalling occurs on the surface of the steel ball, it will change the contact points and contact force distribution between the steel ball and the raceway, intensify the stress concentration in other parts, and accelerate the further damage of the steel ball and the raceway. Moreover, the spalled metal debris may enter the gap between the raceway and the steel ball, aggravating wear and scratching, and further shortening the service life of the slewing bearing.

Plastic Deformation

– Overload Plastic Deformation: When the load borne by a four – point contact slewing bearing exceeds the yield strength of its material, the metal on the surfaces of the raceway and the steel balls will undergo plastic deformation. This deformation usually manifests as pits or protrusions on the surface of the raceway, and the shape of the steel balls may also change. Plastic deformation destroys the original accuracy and geometric shape of the slewing bearing, increases the fit clearance between the steel balls and the raceway, and causes the slewing bearing to shake and become unstable during operation, seriously affecting the working accuracy and reliability of the equipment. For example, in some large – scale cranes, if the slewing bearing undergoes overload plastic deformation, it may cause the jib to shake significantly during rotation, endangering the safety of the hoisting operation.

– Impact Plastic Deformation: When the equipment starts, brakes, or is subjected to external impact loads, the four – point contact slewing bearing will bear a large instantaneous impact force. This impact force may cause local plastic deformation on the surfaces of the raceway and the steel balls. Although the action time of the impact load is short, if the impact force is large enough, it will still cause serious damage to the slewing bearing. Impact plastic deformation may form tiny pits or deformed areas on the surfaces of the raceway and the steel balls. These areas will become stress – concentration points during subsequent operation, accelerating the generation and expansion of fatigue cracks and reducing the service life of the slewing bearing.

Corrosion

– Chemical Corrosion: Four – point contact slewing bearings are usually exposed to various environments. When they come into contact with water vapor, oxygen, and other corrosive media in the air, a chemical reaction occurs on the metal surface, forming corrosion products. For example, slewing bearings made of steel are prone to oxidation reactions in a humid environment, producing rust. Corrosion gradually erodes the material on the metal surface, weakens the strength and wear resistance of the material, and reduces the performance of the slewing bearing. As the corrosion intensifies, the surface of the slewing bearing becomes rough and uneven, and may even develop pits, affecting the fit accuracy between the steel balls and the raceway, increasing the operating resistance of the slewing bearing, and consuming more energy.

– Electrochemical Corrosion: If there is an electrolyte solution in the environment where the slewing bearing is located and there is a potential difference between different metal components, a galvanic cell will be formed, triggering electrochemical corrosion. For example, when the inner and outer rings of the slewing bearing are made of different metal materials or there are unevenness in the surface treatment process, electrochemical corrosion is likely to occur under the action of the electrolyte solution. Electrochemical corrosion accelerates the local corrosion rate of metal components, forming corrosion pits and cracks, and seriously affecting the structural integrity and load – carrying capacity of the slewing bearing.

Fracture

– Raceway Fracture: Raceway fracture is a relatively serious failure mode. The reasons may include defects in the material itself, such as inclusions and pores inside. When subjected to loads, stress concentration is likely to occur at these defective locations, triggering cracks and their expansion. In addition, residual stress generated during the processing process, if not effectively eliminated, may also cause the raceway to crack during subsequent use. Moreover, overload or long – term fatigue can also cause cracks in the raceway, eventually leading to fracture. After the raceway fractures, the slewing bearing cannot normally bear the load, the equipment will stop running immediately, and it may even cause safety accidents.

– Steel Ball Fracture: If there are internal defects in the steel balls during the manufacturing process, such as uneven structure caused by improper forging technology or heat treatment defects, when they are subjected to large impact forces or cyclic stress during use, they may fracture. After the steel ball fractures, it will damage the load – bearing structure of the slewing bearing, change the load distribution borne by other steel balls, accelerate the damage of other components, and may also cause the equipment to vibrate violently and produce abnormal noise.

– Cage Fracture: The cage plays an important role in the slewing bearing. If there are improper installation situations, such as over – tightening or under – tightening during installation, the cage will bear additional stress during operation. In addition, when the slewing bearing is subjected to large external impact forces or interferes with other components, the cage is also easily damaged. After the cage fractures, the steel balls will lose their restraint and may collide with each other and scatter within the raceway, resulting in the complete failure of the slewing bearing.

Price of Four – Point Contact Slewing Bearings

Materials are a crucial factor. Using high – quality steel and special alloys can enhance strength and wear resistance. This increases the cost, and thus the price will be higher. For example, slewing drives made of materials containing special alloys are more expensive than those made of ordinary materials. Machining accuracy is also important. High – precision machining requires advanced equipment and technologies, which increases the cost, and as a result, the product price is naturally higher. The slewing drives used in precision equipment generally have high prices. The manufacturing process also affects prices. Advanced processes can optimize performance but also increase costs, thereby raising the selling price.

Supplier of Four – Point Contact Slewing Bearings

LDB bearing company has risen from obscurity to become well – known in the industry, relying on its dedication to quality and pursuit of innovation. The company is located in Luoyang, Henan Province, where the bearing industry is developed, enjoying the advantages of industrial resources. For example, its self – developed straight – tooth gear slewing drives have high precision and strong stability, greatly improving the operation accuracy and efficiency of industrial welding robots. With high – quality products and attentive services, it has won numerous praises and is bound to create more glories in the future!

How about the Load – Carrying Capacity of Four – Point Contact Slewing Bearings

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As an important mechanical component, four – point contact slewing bearings play a crucial role in many engineering fields. Their load – carrying capacity is an important indicator to measure their performance. They can withstand axial forces, radial forces, and tilting moments under different working conditions, providing reliable support for the stable operation of equipment.

What is Four – Point Contact Slewing Bearing

A four – point contact slewing bearing is a type of bearing structure. It consists of components such as an inner ring, an outer ring, rolling elements, and a cage. Its uniqueness lies in that the rolling elements have four – point contact with the raceways of the inner and outer rings, enabling it to simultaneously withstand axial forces, radial forces, and tilting moments. This design gives the slewing bearing a high load – carrying capacity and rotational accuracy within a limited space. It is commonly used in construction machinery and large – scale equipment such as cranes, excavators, and wind turbines. It can achieve smooth rotational motion between components, adapt to complex working conditions, and improve the reliability and stability of the equipment.

Axial Load – Carrying Capacity

The axial load – carrying capacity of a four – point contact slewing bearing is one of its significant advantages. Structurally, the steel balls have four – point contact with the arc – shaped raceways of the inner and outer rings. This design allows the axial force to be evenly distributed among each contact point. When subjected to an axial load, each steel ball can effectively share the force, thus enhancing the overall axial load – carrying capacity.

Generally, the axial load – carrying capacity of a small – sized four – point contact slewing bearing can reach several tens of kilonewtons. For example, in some small industrial robots, the axial load – carrying capacity of the four – point contact slewing bearings used may be around 30 – 50 kN, which can meet the axial force requirements generated during the movement of the robot arm. For large – scale construction machinery, such as large – scale tower cranes, the axial load – carrying capacity of the four – point contact slewing bearings used can reach several thousand kilonewtons or even higher. In some super – large tower cranes, the axial load – carrying capacity of the slewing bearings may exceed 5000 kN to withstand the huge axial forces generated during the hoisting and rotation of the jib and heavy objects.

Radial Load – Carrying Capacity

Although the four – point contact slewing bearing is not a specialized radial bearing, it still has a certain radial load – carrying capacity. In actual work, equipment often generates axial forces, radial forces, and tilting moments simultaneously. The four – point contact slewing bearing needs to withstand axial forces and tilting moments while also accommodating a certain radial force.

Its radial load – carrying capacity mainly depends on the contact angle between the steel balls and the raceways and the fitting accuracy. When the contact angle between the steel balls and the raceways is reasonable and the manufacturing accuracy is high, the radial load – carrying capacity can be improved to a certain extent. However, compared with specialized radial bearings, the radial load – carrying capacity of four – point contact slewing bearings is relatively weak. For example, in some small rotating worktables, the radial load – carrying capacity of the four – point contact slewing bearings used may be around 10 – 20 kN, while that of specialized radial bearings of the same specification may reach 30 – 50 kN. But in most practical applications, the radial load – carrying capacity of four – point contact slewing bearings can usually meet the radial force requirements generated by the equipment under normal working conditions.

Tilting Moment Load – Carrying Capacity

Four – point contact slewing bearings perform excellently in withstanding tilting moments. When the equipment is in operation, tilting moments are generated due to various factors (such as eccentric loads, wind forces, etc.), which puts forward high requirements for the anti – tilting ability of the slewing bearing.

Through its special structural design, the four – point contact slewing bearing can convert the tilting moment into the pressure between the steel balls and the raceways. When a tilting moment acts, the steel balls on one side are subjected to greater pressure, while those on the other side are under relatively less pressure. By changing the distribution of this pressure, it can resist the tilting moment. Some large – scale four – point contact slewing bearings can withstand tilting moments of up to tens of thousands of kilonewton – meters. For example, in large – scale port cranes, due to their large working radius and high lifting capacity, huge tilting moments are generated during the operation. The four – point contact slewing bearings used can withstand tilting moments of over 50000 kN·m, ensuring the stable operation of the crane under various working conditions.

Factors Affecting the Load – Carrying Capacity

The load – carrying capacity of four – point contact slewing bearings is affected by multiple factors. Firstly, material properties are one of the key factors. High – quality bearing steels, such as GCr15SiMn steel, have high strength, high hardness, and good wear resistance, which can improve the load – carrying capacity and service life of the slewing bearing. Secondly, manufacturing accuracy is also crucial. The machining accuracy of the raceways, the dimensional accuracy, and the roundness of the steel balls directly affect the contact state between the steel balls and the raceways and the even distribution of forces. High – precision manufacturing processes can make the contact between the steel balls and the raceways more uniform when the slewing bearing is under load, thereby improving the load – carrying capacity. In addition, parameters such as the shape and size of the raceways, and the number and diameter of the steel balls also affect the load – carrying capacity. Reasonably designing the shape and size of the raceways and selecting the appropriate number and diameter of the steel balls can optimize the load – carrying performance of the slewing bearing.

Calculation and Selection of the Load – Carrying Capacity

In practical applications, accurately calculating and reasonably selecting the load – carrying capacity of four – point contact slewing bearings is of great importance. Engineers need to perform precise calculations based on the specific working conditions of the equipment, including parameters such as the maximum axial force, radial force, tilting moment, rotational speed, and working temperature, in combination with relevant standards and calculation formulas for slewing bearings. At the same time, a certain safety factor needs to be considered to ensure that the slewing bearing can work safely and reliably during long – term operation. When selecting a slewing bearing, based on the calculation results, refer to the product samples and technical materials provided by slewing bearing manufacturers to select the appropriate specifications and models to meet the load – carrying capacity requirements of the equipment.

Price of Four – Point Contact Slewing Bearings

Materials are a crucial factor. Using high – quality steel and special alloys can enhance strength and wear resistance, increase costs, and thus lead to higher prices. For example, slewing drives made of materials containing special alloys are more expensive than those made of ordinary materials. Machining accuracy is also important. High – precision machining requires advanced equipment and technologies, which increases costs, and as a result, the product prices are higher. The slewing drives used in precision equipment generally have high prices. The manufacturing process also affects prices. Advanced processes can optimize performance but also increase costs, thereby raising the selling price.

Supplier of Four – Point Contact Slewing Bearings

LDB bearing company has risen from obscurity to become well – known in the industry, relying on its dedication to quality and pursuit of innovation. The company is located in Luoyang, Henan Province, where the bearing industry is developed, enjoying the advantages of industrial resources. For example, its self – developed straight – tooth gear slewing drives have high precision and strong stability, greatly improving the operation accuracy and efficiency of industrial welding robots. With high – quality products and attentive services, it has won numerous praises and is bound to create more glories in the future!