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The Influence on Materials of Slewing Bearing

March 31, 2025/in Bearing Knowledge /by wang

In the industrial field, slewing bearings serve as the crucial hubs of various large – scale mechanical equipment. They can be found everywhere, from the tower cranes on construction sites to the rotating bases of astronomical telescopes. A slewing bearing not only has to withstand huge axial forces, radial forces, and overturning moments but also ensures that the equipment can rotate flexibly and smoothly. The realization of all these performances depends on high – quality materials.

What is a Slewing Bearing?

A slewing bearing is a large – scale bearing capable of withstanding comprehensive loads. It plays a vital connecting and supporting role in numerous large – scale mechanical equipment. Its structure mainly consists of an inner ring, an outer ring, rolling elements, and a cage. The relative rotation is achieved through the rolling of the rolling elements between the inner and outer rings, thereby supporting the smooth rotation of equipment components. Slewing bearings can withstand large axial forces, radial forces, and overturning moments and are widely used in equipment such as cranes, excavators, wind turbines, and solar tracking systems. It not only ensures the structural stability of the equipment but also enables the equipment to operate flexibly under complex working conditions, playing a key role in enhancing the overall performance and work efficiency of the equipment.

Characteristics and Applications of Commonly Used Materials

Medium – Carbon Alloy Steel: The Balance of Strength and Toughness

Medium – carbon alloy steel is one of the commonly used materials for slewing bearings, with 42CrMo steel being a typical representative. The carbon content of such steel is between 0.3% – 0.6%. After appropriate quenching and tempering treatments, it can possess excellent strength and toughness. In large – scale port cranes, the slewing bearing needs to bear a lifting weight of dozens to hundreds of tons and also withstand the impacts caused by frequent starting, stopping, and turning. With a yield strength of over 930MPa and a tensile strength of over 1080MPa, 42CrMo steel firmly supports the upper structure of the crane, ensuring the normal rotation of the turntable under heavy workloads, avoiding deformation or fracture due to excessive stress, and ensuring the efficient and safe operation of cargo handling operations.

Alloy Structural Steel: The Combination of Wear Resistance and Toughness

20CrMnTi, a low – carbon alloy carburizing steel, is also an ideal material for slewing bearings. Its carbon content is approximately 0.2%. After carburizing, quenching, and low – temperature tempering treatments, the surface hardness can reach HRC58 – 62, forming a hard and wear – resistant surface layer, while the core still maintains good toughness. In the construction machinery field, such as the slewing platform support of excavators, during operation, it not only has to withstand the strong impact force generated by excavation operations but also resist the wear caused by long – term rotation. The high – hardness surface layer of 20CrMnTi steel after carburization effectively reduces the degree of wear and extends the service life, and the toughness of the core ensures that it will not undergo brittle fracture when subjected to instantaneous impacts, guaranteeing the stable operation of the excavator.

Special – Performance Materials: Coping with Extreme Working Conditions

In some special environments, ordinary alloy steels are difficult to meet the requirements, so special – performance materials have emerged. In the slewing bearings of high – temperature furnaces in the metallurgical industry, high – temperature alloys come into play. For example, the Inconel 718 alloy can still maintain a relatively high yield strength and tensile strength at a high temperature of 650°C. With its good high – temperature strength, oxidation resistance, and thermal stability, it can work stably in a high – temperature environment for a long time, ensuring the normal operation of the furnace. In the marine engineering field, since the equipment is long – term exposed to high – humidity and highly corrosive seawater, 316L stainless steel has become one of the preferred materials for slewing bearings. It is rich in nickel and molybdenum elements and has excellent seawater corrosion resistance, which can effectively resist seawater erosion, prevent rust and corrosion, extend the service life of the equipment, and reduce maintenance costs.

Consideration Factors in Material Selection

The selection of slewing bearing materials is a comprehensive trade – off process. First, the working conditions of the equipment are key factors. The magnitude of the working load, the speed of rotation, and the temperature, humidity, and pH value of the operating environment all determine the required properties of the materials. For example, in the slewing bearings of high – speed centrifuges, the materials not only need to have high strength and hardness but also good dynamic balance performance to avoid vibrations and noises generated by high – speed rotation. Second, the machinability of the materials cannot be ignored, including cutting machinability, forging performance, and heat treatment performance. Materials that are easy to process can reduce manufacturing costs and improve production efficiency. Finally, cost factors also play an important role in material selection. Under the premise of meeting performance requirements, choosing materials with high cost – performance can effectively control the overall cost of the equipment and improve the competitiveness of products.

New Trends in Material Development

With the continuous progress of industrial technology, slewing bearings face more complex working conditions and higher performance requirements, and material development also shows new trends. On the one hand, high – performance materials are constantly emerging. For example, ceramic – matrix composites combine the high hardness and high – temperature resistance of ceramics with the high strength and high toughness of composites, and are expected to be widely used in slewing bearings in fields such as aerospace and high – speed precision machinery. On the other hand, the greening and sustainable development of materials have also become an important direction. The development of environmentally friendly and recyclable materials can not only reduce the impact on the environment but also achieve the recycling of resources. At the same time, the development of material surface treatment technology has opened up new ways to improve the performance of slewing bearings. Through advanced technologies such as nano – coatings and ion implantation, a special – performance layer can be formed on the surface of the materials, further improving their wear resistance, corrosion resistance, and fatigue life.

The Price of Slewing Bearing Materials

The prices of slewing bearing materials are affected by multiple factors. First, the cost of raw materials is a major factor. The price fluctuations of alloying elements such as chromium and molybdenum directly affect the cost of steel. If the steel contains scarce elements such as tungsten and vanadium, the price will increase due to the high difficulty of mining and acquisition. Second, the production process difficulty is also crucial. Advanced smelting and high – precision processing not only require specialized equipment but also rely on high – tech personnel, greatly increasing the cost. Finally, market supply and demand have a significant impact. With the development of the wind power and construction machinery industries, the demand for slewing bearings has increased. When the demand exceeds the supply, the material price rises. Conversely, if the production capacity of material manufacturers is sufficient and the output is high, resulting in oversupply, the price will decline.

Supplier of Slewing Bearings

LDB Bearing always adheres to the concept of “win – win with customers” and embodies the responsibility of modern industry. With innovation and quality at its core, LDB Bearing continuously provides global customers with products and services beyond expectations. LDB Bearing is not only a link in mechanical transmission but also a powerful engine driving the industrial civilization to a higher level.

What is the slewing bearing of a CT scanner?

March 31, 2025/in Bearing Knowledge /by wang

The slewing bearing of a CT scanner is a crucial component. It consists of inner and outer rings, rolling elements, etc., and features high precision, high speed, high stability, high reliability, and low noise. When the CT scanner is in operation, the slewing bearing drives the X – ray tube and detector to rotate rapidly and accurately around the patient, precisely collecting data and ensuring the stable operation of the equipment. Due to the extremely high requirements for image quality in CT scanning, the slewing bearing needs to meet special requirements such as high precision, high – speed rotation, and stability. The performance of the slewing bearing is directly related to the imaging quality and operation efficiency of the CT scanner. With the advancement of medical technology, its role in the medical field will become even more important.

What are the characteristics of the slewing bearing of a CT scanner?

High precision: It needs to reach sub – millimeter or even higher precision to ensure the precise position of the X – ray tube and detector during rotation, avoid image artifacts, and provide accurate data for diagnosis. High speed: It can achieve rapid rotation, greatly shortening the scanning time, improving the inspection efficiency, and reducing the waiting and inspection time of patients. High stability: It operates stably, reducing vibrations and preventing interference with the scanning results due to shaking, ensuring clear and accurate images. High reliability: It can work continuously and stably for a long time, has good fatigue resistance and wear resistance, and reduces equipment failures and maintenance times. Low noise: It produces low noise during operation, creating a quiet inspection environment for patients, reducing psychological stress, and facilitating patient cooperation.

Structural composition

The slewing bearing is mainly composed of core components such as inner and outer rings and rolling elements. The outer ring can be toothed or non – toothed, and the same applies to the inner ring. The sealing strip can effectively prevent dust, impurities, etc. from entering the interior, protecting the rolling elements and raceways. The rolling elements are divided into two forms: balls and rollers, which roll between the raceways of the inner and outer rings to realize the rotation function of the slewing bearing. The oil filling nozzle is used to add lubricant to reduce friction between components; the plugs and plug pins are used to seal relevant oil passages or mounting holes. In addition, there are spacers or cages, whose function is to evenly separate the rolling elements and ensure the orderly movement of the rolling elements.

Model classification

Slewing bearings have a variety of model classifications, and different models are suitable for different working scenarios. The single – row four – point contact ball slewing bearing consists of two raceways, is compact in structure and light in weight. The steel balls contact the circular arc raceways at four points, and it can simultaneously withstand axial force, radial force, and overturning moment. It is commonly used in construction machinery such as rotary conveyors. The double – row ball slewing bearing with different diameters has three raceways. According to the force conditions, two rows of steel balls with different diameters are arranged up and down. It is convenient for open – type assembly and can withstand a large axial force and overturning moment. It is mostly used in handling machinery such as tower cranes with medium – sized or larger diameters. The single – row crossed roller slewing bearing consists of two raceways, is compact in structure, light in weight, high in manufacturing precision, and small in assembly clearance. The rollers are arranged in a 1:1 cross – pattern and can withstand axial force, overturning moment, and a large radial force. It is widely used in fields such as hoisting and transportation, construction machinery, and military products. The three – row roller slewing bearing has three raceways, and the upper, lower, and radial raceways are separated from each other. It can simultaneously withstand various loads and has the largest load – bearing capacity. It is suitable for heavy machinery such as bucket – wheel excavators. The light – type series slewing bearing has the same structural form as the ordinary slewing bearing, but it is lighter in weight and more flexible in rotation. It is applied to fields such as food machinery that have high requirements for weight and flexibility.

Construction and structural features

The slewing bearing usually forms a slewing drive device together with components such as worms, housings, and motors. Its core slewing bearing can simultaneously withstand axial force, radial force, and overturning moment. Some slewing drive products, such as NFB slewing drives, have advantages such as easy installation, easy maintenance, and space – saving installation.

Heat treatment

The raceways are processed by surface induction hardening, and the quenching hardness reaches HRC55 – 62 to ensure a sufficient hardened layer depth, enhancing wear resistance and load – bearing capacity. The teeth on the slewing bearing rings are generally in the heat – treatment state of normalizing or quenching and tempering. The tooth surface can be quenched as required, and the quenching hardness is HRC50 – 60. According to the application scenarios, it is divided into full – tooth quenching and single – tooth induction quenching (which is further divided into tooth – surface – and – root quenching and tooth – surface quenching).

Working mode

The slewing bearing has two basic working modes: one is that the inner ring is fixed to play a supporting role, and the outer ring rotates; the other is that the outer ring is fixed to play a supporting role, and the inner ring rotates.

CT Scanner: The “X – Ray Eye” of Modern Medicine

A CT scanner, that is, a computed tomography device, is an indispensable and important tool in modern medical diagnosis. It emits and receives X – rays from multiple angles around the patient’s body to obtain tomographic images of the human body’s interior, providing doctors with extremely detailed and accurate information for disease diagnosis.

The core role of the slewing bearing in a CT scanner

Driving component rotation

When the CT scanner is working, the slewing bearing shoulders the important task of driving the X – ray tube and detector to rotate rapidly and accurately around the patient. During this process, the slewing bearing must ensure that the position accuracy of the X – ray tube and detector reaches the sub – millimeter level. Only in this way can the X – ray attenuation data inside the human body be accurately collected from different angles, providing a solid guarantee for the subsequent reconstruction of high – quality three – dimensional tomographic images of the human body. For example, in a head CT scan, the slewing bearing drives the X – ray tube and detector to rotate rapidly around the patient’s head, obtaining scan data from multiple angles in a very short time, thus clearly presenting the internal structure of the head.

Ensuring operation stability

CT scanners often need to work continuously for a long time, and the slewing bearing must have excellent anti – fatigue performance. It needs to be able to withstand long – term, high – intensity operation to ensure the stable operation of the CT machine. At the same time, the good rigidity and accuracy retention of the slewing bearing are also crucial, because any vibration or deformation may have a negative impact on the image quality. Take the CT inspection room of a large general hospital as an example. The CT scanner examines a large number of patients every day, and the stable operation of the slewing bearing is directly related to the smooth progress of the inspection work.

Achieving precise positioning

When scanning different parts or executing different scanning protocols, the slewing bearing needs to precisely control the rotation angle and position to make the X – ray tube and detector accurately aim at the target area. For example, in a high – resolution CT scan of the lungs, the slewing bearing needs to accurately adjust the angle to ensure that the X – ray tube and detector can obtain clear images of the fine structures of the lungs, providing accurate basis for doctors to diagnose lung diseases.

Special requirements of CT scanners for slewing bearings

High precision

CT scanning has extremely high requirements for image quality, and the precision of the slewing bearing directly affects the accuracy of the scanning data. Its manufacturing and installation precision requirements reach sub – millimeter or even higher levels to ensure the stable and precise position of the X – ray tube and detector during rotation. Even a slight deviation may lead to image artifacts and affect the doctor’s diagnosis.

High speed rotation and stability

To improve the scanning efficiency, the slewing bearing needs to be able to achieve high – speed rotation while ensuring a stable rotation process. High – speed rotation can shorten the scanning time, reduce the patient’s discomfort and motion artifacts. And stability is the key to ensuring image quality, avoiding impacts on the scanning results due to vibrations, jams, etc. For example, in a cardiac CT scan, only a fast and stable rotation can capture the accurate shape of the heart at different times.

High reliability and durability

CT scanners are used frequently, and the slewing bearing needs to have high reliability and a long service life to reduce equipment maintenance and downtime. This requires the use of high – quality materials and strict quality inspection and durability testing, with good anti – fatigue, wear – resistant and other properties. Once the CT equipment in a hospital fails, it will affect the inspections and diagnoses of a large number of patients. Therefore, the reliability and durability of the slewing bearing are of great significance.

Low noise and low vibration

In order to provide patients with a quiet and comfortable inspection environment and avoid interference with the scanning results, the slewing bearing should minimize noise and vibration during operation. This can be achieved by optimizing the structural design, selecting appropriate rolling elements, and using proper lubrication methods. When patients are examined in a quiet environment, their psychological stress is relatively low, which is also more conducive to their cooperation.

In conclusion, the slewing bearing and the CT scanner are closely connected. The performance of the slewing bearing is directly related to the imaging quality and operation efficiency of the CT scanner. With the continuous development of medical technology, the requirements for slewing bearings and CT scanners will become higher and higher, and they will also play a more important role in the medical field.

The price of the slewing bearing of a CT scanner

The price of the slewing bearing of a CT scanner is affected by many factors. The material is crucial. Slewing bearings made of high – quality steel or special alloys have a relatively high price due to high costs. Precision requirements are also important. The high – precision slewing bearings required for CT scanners have complex manufacturing processes and strict inspections, increasing costs and thus driving up prices. The price also varies depending on the load – bearing capacity. Slewing bearings that can withstand greater axial, radial forces, and overturning moments have more complex structures and materials, resulting in higher prices.

The supplier of the slewing bearing of a CT scanner

Looking to the future, LDB bearing will continue to adhere to the corporate vision of “meticulous manufacturing, serving the world”, continuously increase R & D investment, improve product quality and technical levels, expand market areas, strengthen international cooperation, and strive towards the goal of becoming a world – class bearing manufacturer. It is believed that with the joint efforts of all employees of LDB bearing, this enterprise, which carries numerous honors and dreams, will surely write an even more glorious chapter in the industrial bearing field and make greater contributions to the development of the global industry.

Why Slew bearings Are So Important?

March 29, 2025/in Bearing Knowledge /by wang

In the vast and complex industrial system, there is a seemingly unremarkable yet crucial component – the slew bearing. It’s like the joint of industry, supporting the rotational motion of various machines and enabling the smooth operation of the industrial giant wheels. From daily – used home appliances to high – speed cars, from towering wind turbines to sophisticated medical equipment, slew bearings are everywhere. Despite their small size, they possess great power and are an indispensable part of modern industry.

What Is a Slew bearing

The main function of a slew bearing is to support a mechanical rotating body, reduce the friction coefficient during its motion, and ensure its rotational accuracy. Simply put, it’s like a bridge connecting the rotating components and the fixed machine body, allowing the components to rotate smoothly. Its working principle is based on replacing sliding friction with rolling friction. By placing rolling elements (such as balls or rollers) between the shaft and the slew bearing housing, the friction is greatly reduced. Take the deep – groove ball slew bearing as an example. It is the most representative rolling slew bearing. When the shaft rotates, the balls roll between the inner and outer rings with minimal friction, enabling the shaft to rotate at high speed and smoothly. This design not only improves the mechanical efficiency but also extends the service life of the equipment.

Types of Slew bearings

There is a wide variety of slew bearing types, and different types have different characteristics and application scenarios. Common types include deep – groove ball slew bearings, self – aligning ball slew bearings, cylindrical roller slew bearings, and tapered roller slew bearings.

Deep – groove ball slew bearings have a simple structure, low manufacturing cost, small friction coefficient, and high limiting speed. They are the most widely used, often applied in fields such as motors, automobiles, and home appliances.

Self -aligning ball slew bearings have excellent self – aligning performance and can compensate for coaxiality errors. They are suitable for situations where the shaft is bent under stress or misaligned during installation, such as in mining machinery and metallurgical machinery.

Cylindrical roller slew bearings have a large radial load – carrying capacity and are suitable for heavy – load applications. They can often be found in equipment like machine tool spindles and large – scale motors.

Tapered roller slew bearings can withstand both radial and single – direction axial loads. They are commonly used in industries such as automotive, rolling mills, and mining machinery.

Applications of Slew bearings in Various Fields

Transportation Field: In automobiles, slew bearings are widely used in components such as engines, transmissions, and wheel hubs. The slew bearings in the engine support the rotation of the crankshaft to ensure the normal operation of the engine, and those in the transmission enable efficient power transmission between different gears. It is estimated that an ordinary car requires approximately 100 – 150 slew bearings. In rail transportation, high – precision slew bearings are essential for key parts of high – speed trains, such as traction motor slew bearings and bogie axle box slew bearings. These slew bearings not only need to withstand huge loads but also maintain stable performance at high speeds to ensure the safe and smooth operation of the train.

Energy and Power Field: Wind turbines are an important representative of clean energy. Their main shaft slew bearings, pitch and yaw slew bearings, etc., are core components of the turbines. For a 3MW wind turbine, the outer diameter of the main shaft slew bearing can exceed 2m, and it needs to withstand significant axial and radial loads. The requirements for slew bearings in the nuclear power field are even more stringent. The main pump thrust slew bearing needs to support hundreds of tons of weight, and the control rod drive mechanism slew bearings need to work stably in a high – radiation environment.

High – end Manufacturing Field: In CNC machine tools, the rotational speed of the motorized spindle slew bearings can reach over 40,000 rpm, and the ball screw support slew bearings ensure the high – precision positioning of the machine tool. The crossed roller slew bearings in the RV reducers of industrial robots need to meet an accuracy requirement of ABEC7 or above to ensure the precise and stable movement of the robots. The magnetic levitation slew bearings in semiconductor equipment’s vacuum coating machines can achieve high – precision rotation in a dust – free environment, meeting the strict requirements of semiconductor manufacturing.

Consumer Goods and Daily Life Field: In daily life, slew bearings are also everywhere. The annual demand for air – conditioner compressor slew bearings exceeds 500 million sets, ensuring the efficient operation of air conditioners. The silent slew bearings in washing machines reduce the noise during operation, enhancing the user experience. The slip ring slew bearings in CT machines in medical devices adopt an integrated design of conductive slip rings, enabling 360 – degree rotational scanning of the CT machines.

Development Status and Trends of the Slew bearing Industry

With the continuous development of the global manufacturing industry, the slew bearing industry is also making continuous progress. Currently, the global slew bearing market is huge. In 2023, it reached 143.6 billion US dollars and maintained an annual compound growth rate of 8.3%. Among them, the automotive industry is the largest application field for slew bearings, accounting for 32%, followed by the industrial machinery and energy fields.

In terms of technological development, slew bearings are moving towards the direction of intelligence, lightweight, and high – performance. By using new materials and optimizing the structure, the weight of slew bearings is reduced, and energy consumption is decreased. High – performance slew bearings continue to break through in terms of high – speed, high – precision, and high – reliability.

As the joints of industry, slew bearings, despite their small size, play an irreplaceable role in various fields. Their development not only promotes the progress of industry but also brings convenience to people’s lives. With continuous technological innovation and the expansion of application fields, it is believed that slew bearings will continue to shine in future industrial development and contribute to the goal of becoming a manufacturing powerhouse.

The Price of Slew bearing

Slew bearing prices are affected by multiple factors. In terms of raw materials, the type of steel (such as high – carbon chromium steel or special alloys) and fluctuations in the supply chain directly determine the cost. In the manufacturing process, the higher the precision level, the more stringent the requirements for processing, heat treatment (quenching, carburizing), and surface treatment (plating, nitriding), which increases the production cost. At the same time, import tariffs and transportation costs also significantly affect the final pricing, ultimately forming a price system jointly influenced by materials, technology, and the market.

Supplier of Slew bearing

In terms of product quality, LDB bearing always adheres to the attitude of striving for excellence and has established a strict quality control system. Starting from the procurement of raw materials, it strictly selects high – quality steel to ensure the basic performance of the products. Ensure that every product can meet your needs.

How to Conduct Slew bearing Diagnosis

March 29, 2025/in Bearing Knowledge /by wang

In the modern industrial system, slew bearings, as crucial components of various rotating equipment, their operating status is directly related to the overall performance and production efficiency of the equipment. Once a slew bearing fails, it may lead to equipment downtime, production interruptions, and even safety accidents. Therefore, choosing a suitable slew bearing fault diagnosis method for a specific application is of great significance. This not only helps to detect and resolve potential problems in a timely manner but also effectively reduces maintenance costs and improves the reliability and service life of the equipment.

What Are the features of Slew bearings?

Slew bearings are key components in mechanical transmission and have many distinct characteristics. Structurally, rolling slew bearings generally consist of an inner ring, an outer ring, rolling elements, and a cage, with each part working in coordination; sliding slew bearings mainly include a slew bearing housing and a slew bearing bush. In terms of performance, they can effectively reduce the friction between moving parts and improve mechanical efficiency. They also have a high load – carrying capacity and can withstand radial and axial loads. Slew bearings are available in different accuracy grades to meet the diverse requirements of equipment, from common to high – precision ones. Moreover, slew bearings have good rotational stability, ensuring the stable operation of equipment, and are widely used in various mechanical fields such as automobiles, machine tools, and motors.

Determine Strategies Based on Equipment Characteristics

The fectures of the equipment itself are the fundamental basis for choosing a diagnosis method. Regarding speed and load, slew bearing failures in high – speed equipment can cause high – frequency vibrations. The vibration analysis method, with its ability to capture high – frequency signals, is an ideal choice for such equipment. For example, in a gas turbine, where the slew bearing rotates at an extremely high speed, high – sensitivity acceleration sensors installed at key positions can collect vibration signals in real – time. Through signal processing techniques such as the Fast Fourier Transform, the vibration spectrum can be analyzed to accurately identify slew bearing fault types, such as early wear of the balls and fatigue cracks in the raceways. For heavy – load equipment, like the hoist of a large – scale mining machine, which endures huge pressure for long periods, the slew bearings are prone to problems such as wear and plastic deformation due to overloading. In this case, the combined use of the temperature monitoring method and the oil analysis method can be very effective. Temperature monitoring can promptly detect slew bearing overheating caused by excessive load, while oil analysis can detect the concentration and composition of metal particles in the oil due to wear, enabling the determination of the wear degree and location of the slew bearing.

Make Choices According to the Working Environment

The working environment significantly affects the applicability of diagnosis methods. In high – temperature environments, such as the slew bearings of blast furnace fans in the metallurgical industry, the conventional oil analysis method may produce errors due to the impact of high temperature on the oil performance. In this case, the vibration analysis method and the temperature monitoring method based on infrared technology are more reliable. Infrared thermal imagers can measure the surface temperature of slew bearings from a distance and non – contact, quickly identifying areas with abnormal temperatures. In humid or corrosive environments, such as the slew bearings of chemical equipment, the slew bearings are prone to corrosion failures. Although the visual inspection method can directly observe surface corrosion signs, it is difficult to detect internal corrosion. However, the combination of the vibration analysis method and the ultrasonic testing method can effectively make up for this deficiency. Ultrasonic waves can penetrate the slew bearing material to detect internal micro – defects and the degree of corrosion.

Select Methods According to Fault Types

Different fault types require targeted diagnosis methods. For early – stage faults, the vibration analysis method and the acoustic detection method have unique advantages. Early – stage slew bearing wear, fatigue damage, and other faults can cause weak abnormal vibrations and sound signals during slew bearing operation. Through high – resolution vibration sensors and high – sensitivity acoustic sensors, combined with advanced signal processing algorithms, these subtle changes can be captured. For example, wavelet transform can be used to decompose the vibration signal to extract early – stage fault features and achieve early – warning of faults. The oil analysis method can also play a role in early – stage detection. By analyzing the number, shape, and composition of wear particles in the oil, the wear trend of the slew bearing can be detected in advance.

The diagnosis of sudden faults relies more on methods that can respond quickly. When sudden faults such as part breakage or jamming occur in a slew bearing, the vibration analysis method will detect a sharp increase in the vibration amplitude and a mutation in the frequency components. At the same time, the temperature monitoring method can also detect an instant increase in temperature. These abnormal signals can be quickly alerted through an automated monitoring system, enabling operators to take timely measures to prevent the accident from escalating.

Make Decisions by Weighing Cost – Benefit

Cost – benefit is an important factor that enterprises must consider when choosing a diagnosis method. From the perspective of initial investment, vibration analysis equipment, high – precision oil testing instruments, etc., are expensive. For small and medium – sized enterprises with limited funds or some application scenarios with low requirements for equipment accuracy, such as the ventilation equipment in small factories, it is more practical to use the cost – effective visual inspection method and simple temperature monitoring devices. Considering maintenance costs, the oil analysis method requires regular sampling, sending for inspection, and consuming chemical reagents, which can be costly in the long run; the sensors used in the vibration analysis method need to be calibrated and maintained regularly, also incurring certain costs. Therefore, enterprises need to comprehensively consider the importance of the equipment, the potential losses caused by faults, and the maintenance budget to weigh and choose a suitable diagnosis method.

Arrange Reasonably by Referring to Personnel Skills

The skill level of personnel is also a factor that cannot be ignored. Diagnosis methods such as vibration analysis and oil analysis require professional technicians to collect, analyze, and interpret data. For enterprises lacking professional talents, complex diagnosis methods may not be effectively utilized. In this case, it is more appropriate to choose simple – to – operate and easy – to – understand methods such as visual inspection and temperature monitoring. At the same time, enterprises can improve personnel skills through internal training and external further education to gradually introduce more advanced diagnosis methods.

Select Means by Matching Diagnosis Accuracy

The requirement for diagnosis accuracy determines the level of method selection. For equipment with extremely high accuracy requirements, such as aero – engines and lithography machines, a single diagnosis method is difficult to meet the needs. It is necessary to comprehensively use multiple high – precision methods. The vibration analysis method combined with the oil analysis method, supplemented by non – destructive testing techniques such as X – ray flaw detection and ultrasonic flaw detection, can comprehensively monitor the slew bearing status from multiple dimensions to ensure the safe and reliable operation of the equipment. For general industrial equipment, such as ordinary motors and reducers, under the premise of meeting basic production requirements, relatively simple diagnosis methods can be used to ensure the diagnosis effect while reducing costs.

Determine the Method by Combining Real – Time Monitoring

The need for real – time monitoring varies according to the operating characteristics of the equipment. For key equipment that operates continuously and does not allow downtime, such as the slew bearing of the reactor agitator in a large – scale petrochemical plant, real – time online monitoring methods must be adopted, such as the vibration monitoring system based on the Internet of Things and the real – time oil monitoring system, to ensure that potential fault hazards can be detected in a timely manner. For intermittent – operation equipment, such as tower cranes on construction sites, regular inspections and detections can be carried out. Visual inspections, vibration detections, and oil analyses can be performed during equipment downtime intervals to rationally allocate monitoring resources and improve monitoring efficiency.

The accessibility of the equipment also affects the implementation of the diagnosis method. For slew bearings that are easily accessible, such as the sliding slew bearings on machine tool guides, simple methods such as visual inspection and manually feeling the temperature can be directly used for daily inspections. For slew bearings installed in enclosed spaces, at heights, or in dangerous areas, such as the main pump slew bearings of nuclear power plants, non – contact and remote – operation diagnosis methods are required. For example, robots equipped with detection equipment can be used for vibration detection, and remote infrared monitoring systems can be used for temperature monitoring to ensure the safe and efficient progress of the diagnosis work.

Choosing a suitable slew bearing fault diagnosis method for a specific application is a process of comprehensively considering multiple factors. Enterprises need to weigh the pros and cons based on factors such as equipment characteristics, fault types, cost – benefit, personnel skills, diagnosis accuracy, real – time monitoring requirements, and equipment accessibility, and make scientific decisions. When necessary, a comprehensive diagnosis strategy combining multiple methods can be adopted to achieve accurate diagnosis and effective prevention of slew bearing faults, ensuring the stable operation of equipment and enhancing the production efficiency and competitiveness of enterprises.

The Price of Slew bearings

The price of slew bearings is affected by many factors. Firstly, it is the type. Deep – groove ball slew bearings have a simple structure and a large usage volume, so their prices are affordable; tapered roller slew bearings can withstand combined loads, and their manufacturing process is complex, resulting in relatively high prices. The size specification is also crucial. Large – sized slew bearings require more materials and are difficult to manufacture. For example, large – sized slew bearings used in wind power equipment are expensive; the opposite is true for small – sized slew bearings. In addition, the higher the accuracy grade, the more stringent the processing requirements, and the more expensive the price.

Supplier of Slew bearing

LDB bearing will continue to adhere to the corporate vision of “meticulous manufacturing, serving the world”, continuously increase investment in research and development, improve product quality and technical levels, expand market areas, strengthen international cooperation, and strive towards the goal of becoming a world – class slew bearing manufacturer. It is believed that with the joint efforts of all employees of LDB slew bearing, this enterprise, which carries numerous honors and dreams, will surely write an even more glorious chapter in the industrial slew bearing field and make greater contributions to the development of the global industry.

Key Points of Slew bearing Storage

March 29, 2025/in LDB Company News /by wang

In the industrial field, slew bearings, as crucial components of various mechanical equipment, their performance and quality directly affect the operating efficiency and stability of the equipment. However, many people often overlook the important link of slew bearing storage. A reasonable storage method can effectively maintain the performance of slew bearings, extend their service life, and reduce unnecessary economic losses.

What is a Slew bearing

The design of slew bearings is full of wisdom and ingenuity. With a simple yet sophisticated structure, the inner ring, outer ring, rolling elements, and cage work together to convert sliding friction into rolling friction, minimizing the resistance to motion. This is not only a great innovation in mechanical engineering but also the ultimate pursuit of efficient operation, enabling equipment to achieve maximum value with minimum energy consumption.

Stringent Control of the Storage Environment

The ideal temperature range for slew bearing storage is between 10°C and 25°C. If the temperature is too high, it will accelerate the oxidation and deterioration of the lubricating grease on the slew bearing surface. For example, when the temperature exceeds 35°C, the chemical structure of the grease will gradually change, resulting in a decrease in its viscosity and a significant reduction in lubrication performance. This will not only increase the wear of the slew bearing during subsequent use but may also cause abnormal noise and vibration. Conversely, a too-low temperature is also extremely harmful. In an environment close to 0°C or even lower, the metal material of the slew bearing becomes brittle and its toughness decreases. Once subjected to external impact, even a slight collision, it is very likely to cause cracks on the slew bearing surface, seriously affecting its structural integrity and performance. Moreover, frequent temperature fluctuations cannot be ignored. They will cause internal stress due to inconsistent thermal expansion and contraction of different components inside the slew bearing. Over time, this will lead to a decrease in slew bearing accuracy and even deformation.

Strict Control of Humidity

A relative humidity of 40% – 60% is the optimal humidity condition for slew bearing storage. When the humidity is too high, exceeding 60%, water vapor in the air is likely to condense into small water droplets on the slew bearing surface. These seemingly insignificant water droplets can undergo an electrochemical corrosion reaction with the metal material of the slew bearing, causing rust on the slew bearing surface in a short period. This is especially prominent in coastal areas or during the plum rain season, where extra vigilance is required. When the humidity is lower than 40%, electrostatic phenomena are likely to occur. Static electricity can attract dust and small particles in the surrounding environment. Once these impurities adhere to the slew bearing surface or enter its interior, they will exacerbate wear during the operation of the slew bearing, greatly shortening its service life.

The Ultimate Pursuit of Cleanliness

The storage environment must be kept highly clean, away from dust, oil, and other pollutants. Although dust particles are small, they can cause severe friction with components such as rolling elements and raceways during the operation of the slew bearing, resulting in surface scratches and wear, and thus seriously affecting the accuracy and performance of the slew bearing. The warehouse for storing slew bearings should be regularly and thoroughly cleaned. The floor is preferably paved with dust – proof materials, and high – efficiency air filtration equipment should be installed to minimize the dust content in the air. The harm of oil to slew bearings is also significant. It will not only contaminate the lubricating grease on the slew bearing surface, reducing the lubrication effect, but may also react chemically with the slew bearing metal, causing corrosion. Therefore, operations that may generate oil, such as mechanical equipment maintenance, oil storage, and handling, should be prohibited in the storage area. If it is unavoidable, reliable isolation measures must be taken.

Pay Attention to the Details of Packaging Protection

The original packaging equipped when the slew bearing leaves the factory plays an irreplaceable role. The original packaging is carefully designed to not only effectively prevent moisture and dust but also buffer external impacts during transportation and storage, protecting the slew bearing from damage. The original packaging of high – precision slew bearings usually has a special sponge or foam lining inside, which can tightly wrap the slew bearing to prevent it from shaking inside the package. Before the slew bearing is used, it is necessary to properly protect the integrity of the original packaging and never remove it casually. At the same time, regularly check whether the original packaging is damaged or damp. If the original packaging is slightly damaged, it should be promptly sealed and repaired with tape. If it is severely damp, the packaging needs to be replaced, and the slew bearing should be carefully inspected to see if it has been affected.

Scientific Selection of Placement Methods

Slew bearings should always be placed horizontally. This is because the internal structure of the slew bearing is optimized based on the horizontal stress state during design. If it is hung vertically, the rolling elements and raceways of the slew bearing will be affected by uneven gravity. Over time, the raceway may deform, affecting the rotational accuracy of the slew bearing. For large – sized slew bearings, horizontal placement can also avoid local pressure concentration caused by their own excessive weight, preventing dents or deformations on the slew bearing surface. At the same time, regardless of the size of the slew bearing, it should be avoided to stack them too high. The stacking layer of small – sized slew bearings should not exceed 5 layers, that of medium – sized slew bearings should not exceed 3 layers, and large – sized slew bearings should be placed in a single layer as much as possible. If multi – layer storage is required, special shelves or pallets should be used, and ensure that there is sufficient support and spacing between each layer.

Clear Management of Classified Storage

Slew bearings of different models and specifications must be stored separately and clearly marked. They can be classified according to parameters such as the inner diameter, outer diameter, and type of the slew bearing. Slew bearings of the same model are stored in the same area, and information such as the model, specification, and quantity should be marked on the shelves or storage containers. This not only facilitates quickly and accurately finding the required slew bearings when needed but also avoids incorrect use caused by confusion. At the same time, new slew bearings, used slew bearings, and slew bearings with quality problems should be strictly stored separately. Used slew bearings may have potential problems such as wear and fatigue. Mixing them with new slew bearings is likely to cause misapplication. Slew bearings with quality problems should never be mixed with qualified products. They should be stored separately and clearly marked to prevent them from entering the normal use link.

Meticulous Appearance Inspection

It is recommended to conduct an appearance inspection of the stored slew bearings once a month. Carefully check whether there are any abnormal conditions on the slew bearing surface, such as rust, discoloration, scratches, and deformation. Rust is the most common problem. Once rust spots are found on the slew bearing surface, the cause should be immediately analyzed and corresponding rust – removal and anti – rust measures should be taken. Discoloration may be caused by the deterioration of the lubricating grease, high temperature, or chemical erosion. It is necessary to further check the internal condition of the slew bearing. Scratches and deformations will directly affect the performance of the slew bearing. If found, it is necessary to evaluate their impact on use and decide whether to repair or scrap the slew bearing.

Indispensable Rotation Inspection

For slew bearings stored for a long time, a rotation inspection should be carried out every three months or so. Slowly and evenly rotate the slew bearing to feel whether its rotation is smooth and whether there are any abnormal phenomena such as jamming or abnormal noise. The rotation inspection can prevent the internal parts of the slew bearing from sticking or seizing due to long – term immobility, ensuring that it can operate normally when in use. If the slew bearing is found to rotate unevenly or make abnormal noises during the rotation inspection, stop rotating immediately and conduct a comprehensive inspection of the slew bearing. It may be caused by reasons such as dry lubricating grease, rust or damage of internal parts. It is necessary to take corresponding measures according to the specific situation, such as replenishing lubricating grease, rust – removal, repair, or replacement of parts.

Slew bearing storage is a task that requires great attention to details. From the strict control of the storage environment, the careful handling of packaging protection, to the reasonable planning of the storage method and the effective establishment of a regular inspection mechanism, each link is closely connected and jointly determines the quality and service life of the slew bearing. Only by following scientific storage methods can we ensure that the slew bearing can perform optimally when needed and provide a solid guarantee for the smooth progress of industrial production.

The Price of Slew bearings

The price of slew bearings is affected by many factors. The material is the foundation. Ordinary carbon steel is affordable, while special materials such as ceramics and stainless steel have higher costs due to their outstanding performance and complex processing. Precision is also crucial. Ordinary precision can meet the requirements of general equipment, while high – precision grades are used in high – end fields. The manufacturing process is strict, and the price naturally rises. Custom – made slew bearings cost much more than conventional ones due to special specifications and performance requirements.

Supplier of Slew bearing

Since its establishment in 1999, LDB bearing has been rooted in Luoyang, Henan, a slew bearing production base in China. With the unique industrial environment and its own unremitting efforts, it has gradually grown into a comprehensive enterprise integrating design, development, manufacturing, and sales. After more than two decades of trials and tribulations, LDB slew bearing has always adhered to its original intention, committed to providing high – quality slew bearing products to global customers. It has stood out in the fierce market competition and won wide recognition and trust.

How to Distinguish Ball Bearings and Roller Bearings

March 16, 2025/in Bearing Knowledge, LDB Company News /by wang

The crossed roller slewing bearing is a high-precision and high-rigidity slewing bearing. Its rolling elements are cylindrical rollers, which are arranged vertically and crosswise in the raceway.

Feature of Ball Bearings

Primarily composed of balls, inner rings, outer rings, and retainers. Generally, for industrial ball bearings, the balls and rings are made of high-chromium steel, while the retainers are less hard compared to the balls and rings, and can be made of metal or non-metal materials.

Advantages of ball bearing.

Low friction resistance: Compared to other types of bearings, ball bearings have lower rotational friction resistance, resulting in lower temperatures generated by friction at the same speed.Ability to withstand combined loads: Can handle both radial and axial loads simultaneously, though the load capacity is relatively lower compared to roller bearings.Less sensitive to lubrication interruption: Short-term lubrication interruptions have relatively less impact on their performance.No self-excited instability: Operates more stably, less prone to self-excited instability.Easy to start at low temperatures: Easier to start in low-temperature environments, quickly reaching normal operating conditions.

Classification of Ball Bearings

Deep groove ball bearings: Simple structure, easy to use, mass-produced, widely used, mainly for radial loads, can also handle some axial loads.

Angular contact ball bearings: The contact points between the balls and the inner and outer rings are angular, capable of withstanding higher axial and radial loads, with high rigidity and precision, suitable for high-speed machinery.

Self-aligning ball bearings: Have two rows of steel balls, inner rings with two raceways, outer ring raceways are spherical, with self-aligning properties, can automatically compensate for coaxiality errors caused by shaft deflection and housing deformation.

Thrust ball bearings: A separable bearing, the shaft washer, housing washer can be separated from the cage and ball assembly, can only withstand axial loads, single-direction thrust ball bearings can only withstand axial loads in one direction, double-direction thrust ball bearings can withstand axial loads in both directions.

The feature of roller bearing.

Roller Bearing are a type of rolling bearing that uses rollers as rolling elements, relying on rolling contact between main components to support rotating parts, widely used in modern machinery. The following is a detailed introduction:

Structural Composition

Radial roller bearings: Composed of inner rings, outer rings, rollers, and retainers. Rollers are arranged between the outer diameter surface of the inner ring and the inner diameter surface of the outer ring, the retainer evenly distributes the rollers, preventing mutual contact friction.

Thrust roller bearings: Rollers and retainers are sandwiched between two washers, the structure can be integral or split, determined by assembly convenience.

Rolling Element Shapes

Cylindrical roller bearings: Rollers are cylindrical, radial type only withstands radial loads, thrust type only withstands thrust loads.

Needle roller bearings: Rollers are slender like needles, with the smallest outer diameter for the same inner diameter, suitable for places with small radial space.

Tapered roller bearings: Rolling elements are conical, can withstand loads perpendicular to the shaft and axial loads in a fixed direction.

Spherical roller bearings: Rolling elements are barrel-shaped, can withstand loads perpendicular to the axis and axial loads in both directions, with good self-aligning properties.

Advantages of Roller bearing

High load capacity: Rolling elements and raceways are in line contact, high load capacity, small deformation after loading.

High rotational accuracy: Ensures precise positioning of rotating components, making equipment operation smoother.

Low starting torque: Requires less torque to start, saving energy, improving equipment efficiency.

Ball bearings and roller bearings can be distinguished in the following aspects:

Observing Rolling Element Shapes

Ball bearings: Rolling elements are spherical, usually steel balls, but can also be ceramic balls.

Roller bearings: Rolling elements are cylindrical, conical, or barrel-shaped rollers.

Comparing Load Capacity

Ball bearings: Rolling elements and raceways are in point contact, small contact area, relatively lower radial and axial load capacity, but more balanced performance under combined loads.

Roller bearings: Rolling elements and raceways are in line or surface contact, large contact area, can disperse loads, significantly higher radial load capacity than ball bearings, axial load capacity depends on roller type.

Comparing Speed Performance

Ball bearings: Rolling element shape suitable for high-speed operation, low friction resistance, low heat generation, high limiting speed.

Roller bearings: Large contact area, high friction resistance, prone to heat generation, suitable for medium and low-speed equipment, relatively lower limiting speed.

Feeling Vibration and Noise Levels

Ball bearings: Spherical rolling element design, smoother operation, generally lower vibration and noise levels.

Roller bearings: Due to rolling element shape and contact method, may produce more vibration and noise in certain applications.

Considering Installation and Maintenance Difficulty

Ball bearings: Simple structure, generally easier to install and maintain.

Roller bearings: Complex manufacturing process, higher installation precision requirements, relatively higher maintenance cost and time.

Viewing Application Scenarios

Ball bearings: Suitable for high-speed, precision equipment, such as motors, machine tools, bicycles, etc.

Roller bearings: Used for high-load, long-life applications, such as heavy machinery, automobiles, railway vehicles, etc.

Price of Roller Bearings and Ball Bearings

Different types of roller bearings or ball bearings have different prices due to structural and manufacturing process differences. For example, thrust roller bearings are relatively complex in structure, generally more expensive than ordinary cylindrical roller bearings; high-precision angular contact ball bearings are difficult to manufacture, more expensive than ordinary deep groove ball bearings. Common materials include chromium steel, stainless steel, bearing steel, etc. If special materials such as ceramics are used, the cost will significantly increase, and the price will also be higher. Bearings made of special materials have high temperature resistance, corrosion resistance, etc., suitable for special working conditions.Of course, LDB-Bearing company will provide you with the best production assembly and the most favorable prices. If you want to know more, you can contact us.

What is Double Row Ball Slew Bearing?

March 16, 2025/in Bearing Knowledge /by wang

It is a two-row ball structure and is widely used in mechanical equipment requiring high-precision rotation and heavy-load capacity. A double row ball slew bearing is a large rotational bearing designed to withstand combined axial loads, radial loads, and overturning moments.

What is the feature of Double Row Ball Slew Bearing?

The double-ball slewing bearing integrates innovative design and practical functions. It has a compact structure and occupies a small space, enabling efficient operation within a limited space and being adaptable to a variety of precision equipment.The unique double-ball structure greatly enhances its load-bearing capacity, allowing it to withstand axial and radial loads as well as overturning moments simultaneously, and making it suitable for complex working conditions.The high-precision manufacturing process ensures the slewing accuracy, enabling smooth operation, reducing vibration and noise, and extending the service life of the equipment.It is easy to install and has a low maintenance cost, which can effectively reduce the downtime and improve production efficiency. Widely used in fields such as construction machinery and automated equipment, it is a key component that promotes the efficient development of the industry.

Basic Structure of Double Row Ball Slew Bearing

Double Row Ball Arrangement:Two independent rows of steel balls (rolling elements) are arranged in concentric raceways, allowing simultaneous distribution of loads in different directions.

Inner and Outer Rings: Precision-machined raceways on the fixed outer ring and rotating inner ring (or vice versa), often integrated with gear teeth to drive rotation.

Seals and Lubrication: Equipped with sealing rings to prevent contamination and lubrication ports for regular greasing to extend service life.

Core Functions

Multi-Directional Load Capacity:

Axial Loads: Forces along the rotation axis (e.g., vertical pressure from cranes).

Radial Loads: Forces perpendicular to the rotation axis (e.g., lateral forces from robotic arms).

Overturning Moments: Torque caused by eccentric loads (e.g., twisting forces from wind turbine blades).

High Rigidity Rotation

The double row ball structure distributes stress, minimizes deformation, and ensures smooth rotation.

Advantages and Disadvantages of Double Row Ball Slew Bearings

Advantages:

High Load Capacity: Multi-directional load support: Suitable for complex stress scenarios (e.g., wind turbines, cranes). Double row design: Distributes loads across two rows, improving capacity by 30%~50% compared to single-row bearings and reducing localized stress.

Smooth Operation with Low Friction: Small ball contact area reduces friction, enabling precise control (e.g., medical devices, radar antennas). Low heat generation extends lubrication intervals and bearing life.

Compact and Integrated Design: Integration of gears (internal/external teeth), seals, and lubrication ports saves space. Ideal for applications with strict space constraints (e.g., industrial robot joints).

Versatility

Material options (standard steel, stainless steel, anti-corrosion coatings) adapt to diverse environments (humid, corrosive). Suitable for low-speed heavy-load and medium-speed rotation scenarios.

Disadvantages

Limited Adaptability to Extreme Overturning Moments: Prone to ball slippage under high overturning moments compared to **crossed roller bearings, leading to localized wear. Extreme torque scenarios (e.g., heavy-duty machine tool turntables) require crossed or triple-row roller bearings.

High Installation Precision Requirements:

Base flatness tolerance must be ≤0.1 mm/m; deviations cause uneven raceway loading and accelerated fatigue failure. Demands experienced installers; improper installation risks early failure.

Higher Maintenance Costs:

Regular lubrication (every 500 operating hours) and seal replacement are critical; contamination shortens lifespan. Replacement in heavy machinery (e.g., wind turbines) requires costly disassembly and crane operations.

Cost-Performance Trade-offs: More expensive than single-row ball bearings but weaker in load capacity than crossed roller bearings. Oversized models (e.g., diameter >5 meters) face manufacturing challenges and long lead times.

Application examples of this kind of bearings

In a wind turbine, the double-row ball slewing bearing is installed between the top of the tower and the nacelle:Axial force: The vertical pressure generated by the self-weight of the blades and the nacelle.Radial force: The lateral thrust caused by the wind shear force.Overturning moment: The torque generated by the aerodynamic imbalance during the rotation of the blades.

The load is dispersed through the two rows of balls, ensuring that the nacelle can yaw stably to align with the wind direction even under strong winds.

Factors Influencing the Price of Double Row Ball Slew Bearings

The price of double row ball slew bearings is affected by multiple factors, including raw materials, manufacturing processes, and market dynamics.

Material Costs:

Steel Type:

Standard bearing steel (e.g., GCr15) is cost-effective but corrosion-prone.

Stainless steel (e.g., 440C) or specialty alloys (e.g., 42CrMo4) cost 30%~50% more but suit harsh environments (e.g., marine applications).

Heat Treatment

Processes like carburizing and surface hardening improve hardness and wear resistance but add 15%~25% to processing costs.

Size and Load Capacity:

Diameter Range:

Small bearings (diameter <1 meter): ¥10,000–¥50,000. Large bearings (diameter >3 meters, e.g., for wind turbines): ¥500,000–¥2,000,000 due to material and machining complexity.

Load Rating:

High-load designs (dynamic load rating >500 kN) require reinforced raceways and balls, increasing costs by 20%~40%.

Manufacturing Complexity:

Raceway Machining Accuracy:

High-precision grinding (Ra ≤0.4 μm) costs 30%~50% more than standard turning (Ra ≤1.6 μm) but extends service life.

Gear Integration:

Internal/external gear machining requires specialized equipment; each precision grade improvement (e.g., DIN Class 6) adds 10%~15% to costs.

Seal Design:

Multi-lip or labyrinth seals cost 20%~35% more than standard rubber seals but offer superior dust/water resistance.

Customization Requirements:

Non-Standard Designs:

Customized mounting holes or flange interfaces increase design and tooling fees (10%~20% of total cost).

Special Coatings

Zinc plating, Dacromet, or PTFE anti-corrosion coatings add 5%~15% to costs but suit chemical or marine environments.

Market Factors:

Supply-Demand Dynamics:

Prices rise 10%~30% during high-demand periods (e.g., 2021 wind power installation surge).

Regional Cost Differences

Chinese-made bearings are 30%~50% cheaper than European/American equivalents due to lower labor and material costs.

Transportation and Installation Costs

Logistics

Oversized bearings (e.g., 5-meter diameter) require special transport, with freight accounting for 5%~10% of total cost.

Installation Complexity

High-precision installation (flatness ≤0.1 mm/m) demands professional teams, increasing labor costs by 5%~8%.

The double-row ball slewing bearing optimizes the load distribution through two rows of balls. It is a key component that balances the load-bearing efficiency and space occupation, and is widely used in heavy-duty rotating equipment that needs to bear complex loads. However, its installation accuracy and maintenance requirements are relatively high, and a comprehensive selection should be made according to the working conditions.

The price of double ball slewing bearing

The price of double ball slewing bearing is influenced by multiple factors. Raw material costs are crucial. Fluctuations in the prices of steel and other materials directly affect the product. The complexity of the manufacturing process, such as high – precision processing and the creation of the unique double ball structure, means that the more complex the process, the higher the cost. Different requirements for load – bearing capacity and precision also lead to price differences. Products with high load – bearing capacity and high precision are more expensive due to the greater investment in technology and quality control. When the supply is in short supply, the price rises, and when the supply exceeds demand, the price falls.

Supplier of Double Ball Slewing Bearings

If you want to purchase bearings, you can get in touch with us. LDB-Bearing Company has advanced bearing manufacturing techniques and ensures strict compliance with national standards. Moreover, our R&D team has continuously received research and development funds, which guarantees that we won’t fall behind our peers. We can provide you with different bearings tailored to various industries. Meanwhile, we have a complete after-sales service system. Once you have any problems, we will reply to you immediately and offer reasonable solutions. If you’d like to know more, please feel free to contact us.

What is high-quality slew bearing?

March 12, 2025/in Bearing Knowledge /by wang

A bearing is a core component in mechanical engineering. Its core functions can be summarized as: supporting rotating components, reducing friction, and ensuring the efficient and smooth operation of machinery. Simply put, it is a key part that enables machines to “rotate smoothly”.

What is the feature of slew bearing?

Slewing bearing supports have the following characteristics: They can withstand axial forces, radial forces, and overturning moments simultaneously, and can achieve a relatively smooth 360-degree slewing motion. With a compact structure, they occupy a small space, effectively saving the space of the equipment. They are easy to install and can be easily connected and matched with other components. They have a relatively high precision, which can ensure the accuracy and reliability of the slewing motion. They have a large load-bearing capacity, are suitable for various heavy-duty working conditions, and are widely used in fields such as construction machinery and port machinery.

Classification of slew Bearings

There are many ways to classify slew bearings. Here, based on the working principle, we can divide them into:

Rolling bearings: Their main feature is that rolling elements (such as steel balls, rollers) roll between the inner and outer rings to reduce friction.

Advantages: Low friction, high efficiency, and easy maintenance.Disadvantages: Sensitive to foreign objects and require regular lubrication.

Sliding bearings: They have no rolling elements and rely on a lubricating film for direct sliding (such as bearing bushes).

Advantages: Simple structure, impact-resistant, and suitable for high-speed and heavy-load applications.Disadvantages: High friction and require continuous lubrication.

Application of Slew Bearings

Industrial Field

Machine tools: High-precision bearings are used in the spindles of machine tools to ensure the rotational accuracy during tool cutting, guaranteeing the dimensional accuracy and surface quality of the machined parts.

Motors: The rotor of a motor is supported by bearings, enabling the rotor to rotate smoothly, reducing friction losses, and improving the efficiency and service life of the motor.

Metallurgical equipment: For example, the bearings in steel rolling mills need to withstand huge rolling forces to ensure the stable rotation of the rolls and achieve the rolling of steel.

Transportation Field

Automobiles: Wheel hub bearings support the wheels of automobiles, bearing the weight of the vehicle and various forces during driving. At the same time, they ensure the free rotation of the wheels, which is crucial for the vehicle’s handling and safety.

Trains: Axle box bearings are used between the train axles and bogies, adapting to high-speed driving and heavy-load requirements, and ensuring the stability and reliability of train operation.

Aircraft: The bearings in aircraft engines need to operate under high temperature, high speed, and high load conditions, ensuring the stable rotation of the engine rotor, and are key components for the reliable operation of the engine.

Home Appliance Field

Air conditioners: The bearings in air conditioner compressors ensure the rotation of the compressor crankshaft, enabling the compressor to efficiently compress and transport refrigerant.

Washing machines: The rotation of the inner drum of a washing machine relies on bearings for support. They can bear the weight of clothes and water, ensuring the stable operation of the washing machine at different speeds.

Other Fields

Medical devices: High-precision bearings in devices such as CT scanners and MRI machines ensure the precise rotation and positioning of the scanning components, improving the imaging quality.

Robots: The bearings at the joints of robots enable the joints to rotate flexibly, enabling various complex movements, and play a key role in the motion accuracy and stability of robots.

Wind turbines: The main bearings support the impeller shaft of wind turbines, bearing huge axial and radial loads, ensuring the stable rotation of the impeller under different wind speeds and converting wind energy into electrical energy.

How to maintain the bearing

Application Scenarios and Load Requirements

Load Type: Determine the type of load (radial, axial, or combined load) that the bearing will bear, and select the corresponding bearing type (for example, deep groove ball bearings are suitable for radial loads, and tapered roller bearings are suitable for combined loads).

Load Magnitude: Select the bearing size and load-carrying capacity according to the load intensity (refer to dynamic/static load parameters).

Rotational Speed Requirements: For high-speed applications, choose bearings with low friction (such as angular contact ball bearings or ceramic bearings), and ensure that the rated speed limit is not exceeded.

Adaptability to the Working Environment

Temperature:

High-temperature environment: Choose high-temperature-resistant materials (such as stainless steel, ceramic bearings) or adopt cooling measures.

Low-temperature environment: Use low-temperature grease or special alloy bearings.

Corrosion: In humid or chemically corrosive environments, give priority to stainless steel, coated bearings, or sealed bearings.

Dust/Pollution: Select bearings with rubber seals (such as 2RS type) or dust covers (such as ZZ type), or install protective covers externally.

Bearing Types and Structures

Rolling bearings (such as ball bearings, roller bearings):

Advantages: Low friction, high efficiency, and easy maintenance.

Applicable scenarios: Medium to high speed, low impact load (such as motors, machine tools).

Sliding bearings (such as bearing bushes, self-lubricating bearings):

Advantages: Impact-resistant, suitable for heavy-load or low-speed applications.

Applicable scenarios: Metallurgical equipment, large machinery.

Materials and Processes

Material Selection:

Ordinary steel: Economical, suitable for general industrial environments.

Stainless steel: Corrosion-resistant, suitable for the food and chemical industries.

Ceramics (such as silicon nitride): High-temperature-resistant, lightweight, suitable for high-speed or extreme environments.

Manufacturing Process: High-precision bearings (such as P4/P5 grade) are used in precision equipment (such as machine tool spindles, medical instruments).

Lubrication Management

Lubrication Methods:

Grease lubrication: Suitable for medium to low speed, maintenance-free scenarios (such as lithium-based grease).Oil lubrication: Suitable for high speed, high temperature, or heavy load (such as ISO VG 32 – 100 mineral oil).Sealing Design: Sealed bearings (such as rubber-sealed) can reduce contamination and extend the lubrication cycle.

The Price of Bearings

The price of bearings is affected by many factors. For example, different brands use different processes, which will affect the price. Different materials also have different applications, which also affect the price. In addition, market demand is one of the main factors. LDB Company provides many different types and uses of bearings. If you want to know more, you can contact us.

Slew Bearing manufacturer

LDB was established in 1999. It is a company that focuses on scientific and technological innovation, with more than 20 utility model patents, and has won many honorary titles such as Henan Provincial Science and Technology-based Small and Medium-sized Enterprise. We are committed to the design, development, manufacturing, and sales of slewing drives and slewing bearings. If you want to inquire or purchase bearings, you can consult us.

Comprehensive guide on Slewing Ring Bearing

January 7, 2025/in Slewing Bearing Knowledge /by ldbadmin

What is a Slewing Ring Bearing?

A slewing ring bearing (also known as a turntable bearing or slew bearing) is a type of large bearing designed to accommodate axial, radial, and moment loads simultaneously. It typically consists of an inner ring, outer ring, rolling elements (such as balls or rollers), and a raceway. These bearings are used in applications where rotational movement is required, often with heavy loads and low to moderate speeds.

Types of Slewing Ring Bearings

Slewing ring bearings can be classified based on several factors, including the type of rolling element and the arrangement of the bearing components:

Four-point contact bearings: These have four contact points between the balls and the raceways, allowing them to carry both axial and radial loads along with tilting moment loads. They are commonly used in applications where the load is evenly distributed.
Crossed roller bearings: In these, the rollers are arranged in a criss-cross pattern, offering high load capacity and rigidity. They can handle high axial and radial loads with better precision, often used in precise rotating mechanisms.
Ball type slewing bearings: These use balls as rolling elements and are suitable for applications with lighter loads and moderate rotational speeds.
Roller type slewing bearings: These use cylindrical or tapered rollers for heavier-duty applications, providing a higher load capacity than ball type bearings.
Triple-row bearings: These have three rows of rolling elements—balls or rollers—allowing them to handle higher loads and improve stiffness. They are often used in large machinery like cranes and excavators.

Features of Slewing Ring Bearings

Load handling: Slewing ring bearings are capable of supporting axial, radial, and moment loads simultaneously, making them ideal for machines that require rotational movement under heavy loads.
Precision: Many slewing ring bearings are designed with high precision to maintain accurate and smooth rotational movement.
Compact design: The compact nature of slewing ring bearings makes them suitable for applications with space constraints.
Durability: They are typically made from high-strength steel or other durable materials to withstand harsh operating conditions.
Versatility: Slewing ring bearings can be custom-made to fit specific applications, allowing for flexible design options.
Sealing: Many slewing bearings come with integrated seals to prevent contamination and reduce maintenance needs.

Applications of Slewing Ring Bearings

Crane systems: Used in tower cranes, mobile cranes, and crawler cranes to allow rotation and movement of heavy loads.
Wind turbines: For the yaw bearing in wind turbine systems, allowing the turbine to rotate and face the wind.
Construction equipment: Excavators, loaders, and other heavy machinery use slewing ring bearings for rotational movement.
Marine applications: Used in the turntables of radar, communication, and other systems aboard ships.
Solar tracking systems: In solar panels, slewing rings help with tracking the sun’s position to maximize energy capture.
Heavy industrial machinery: In machines like rotary tables and turntables for precise rotation under load.

How to Select Slewing Ring Bearings?

Selecting the right slewing ring bearing depends on several factors:

Load requirements: Determine the axial, radial, and moment loads the bearing must support. The type and size of the bearing should be chosen based on the load capacity needed.
Rotational speed: Consider the speed at which the bearing will rotate. Higher speeds might require bearings with lower friction and specialized materials.
Operating environment: If the bearing will operate in harsh conditions (extreme temperatures, dust, moisture), ensure it has appropriate seals and coatings to withstand these conditions.
Precision and rigidity: For applications requiring high precision and low deflection, like robotics or industrial machinery, choose a bearing with high rigidity, such as crossed roller bearings.
Space limitations: If space is a concern, a smaller, lighter slewing ring bearing may be necessary. Ensure that the bearing fits within the required dimensions without compromising performance.
Material selection: Choose the material based on the operating environment (corrosion resistance, high strength, etc.). Common materials include high-strength steel, stainless steel, and sometimes ceramic components for special applications.
Maintenance and longevity: Consider the maintenance needs of the bearing, including lubrication intervals, ease of replacement, and expected operational lifespan.

By carefully evaluating these factors, you can select the slewing ring bearing best suited to your application, ensuring optimal performance and longevity.

Supplier of Slewing Ring Bearing

LDB Bearing is a professional slewing ring bearing manufacturer has rich experience in supplying high quality and precision slewing bearing for large projects. If you are looking for slewing ring bearing for your projects, feel free to contact us.