What is Double Row Ball Slew Bearing?

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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.

How to Prolong the Service Life of Slew Bearings

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Slewing bearings are core components of equipment, and it is of utmost importance to maintain them. Maintenance can extend their service life, reduce the failure rate of the equipment, and avoid economic losses caused by downtime due to failures.

What is the feature of slew bearings?

Bearings are crucial components in mechanical transmission. They reduce friction, making equipment run more smoothly and effectively minimizing energy consumption. With high load – bearing capacity, they can withstand loads in different directions such as axial and radial directions. Their high precision ensures the operational stability and reliability of equipment. Widely used in various machinery, bearings significantly enhance the mechanical performance and service life.

How to Prolong the Service Life of Slew Bearings

In the operation of machinery, the significance of bearings is beyond doubt. Maintenance, meanwhile, is crucial for ensuring that bearings can operate efficiently over an extended period. To prolong the service life of bearings, it is necessary to comprehensively optimize multiple aspects, including design and selection, installation, lubrication, maintenance, and the operating environment. I’ve got a set of tried-and-true slew bearing maintenance methods, and I’m eager to share them with you.

Correct Selection and Design

Match Loads and Speeds

Select the type of bearing (such as deep groove ball bearings, tapered roller bearings, etc.) according to the actual load type (radial/axial/combined load) and magnitude.

For high – speed applications, give priority to rolling bearings with low friction (such as angular contact ball bearings) or ceramic bearings.

Consider the Operating Conditions

In high – temperature and corrosive environments: Select stainless – steel bearings or ceramic bearings.

In dusty and humid environments: Choose bearings with seals (such as deep groove ball bearings with rubber seals).

Reserve a Life Margin

Calculate the dynamic load factor (referring to the ISO 281 standard) to ensure that the theoretical life far exceeds the actual requirements.

Standardized Installation and Dismantling

Avoid Mechanical Damage

Use special tools (such as hydraulic presses) for installation, and direct hammering of bearings is prohibited.

Ensure that the tolerance fit between the shaft and the bearing housing meets the standards. An overly tight fit can cause deformation, while an overly loose fit can lead to slippage.

Alignment and Balancing

Check the coaxiality of the shaft and the bearing housing to avoid uneven loading (calibrate using a laser alignment instrument).

High – speed rotating shafts need to be dynamically balanced to reduce additional loads caused by vibration.

Clean the Installation Environment

Clean the shaft, bearing housing, and tools before installation to prevent foreign objects (such as metal shavings, dust) from entering the bearing.

Scientific Lubrication Management

Select the Appropriate Lubricant

Grease Lubrication: It is highly versatile and suitable for medium – to – low – speed applications (such as lithium – based grease, complex calcium sulfonate grease).

Lubricating Oil: It is suitable for high – temperature, high – speed, or heavy – load scenarios (such as mineral oils or synthetic oils with ISO VG 32 – 100).

For special environments: Use food – grade lubricating grease (certified by NSF H1) or high – temperature lubricating grease (such as polyurea – based grease).

Control the Lubrication Quantity

The grease filling amount should be 30% – 50% of the internal space of the bearing. Excessive filling can cause overheating.

Regularly replenish the lubricating grease (according to the operating hours or the recommendations in the equipment manual, for example, replenish the grease every 2000 operating hours).

Avoid Contamination

Use clean lubricants, and the lubrication tools (such as grease guns) should be dedicated to prevent the mixing of impurities.

Thoroughly remove the old grease when replacing the lubricant.

Daily Maintenance and Monitoring

Regular Inspections

Vibration Detection: Use a vibration analyzer to monitor abnormal vibrations (to detect spalling and wear at an early stage).

Temperature Monitoring: If the bearing temperature rises by more than 30°C above the ambient temperature, stop the machine for inspection.

Noise Analysis: Abnormal metal friction noises may indicate poor lubrication or internal damage.

Seal Protection

Check whether the seals are aged or damaged and replace them in a timely manner (for example, double – lip seals are better than single – lip seals).

In a dusty environment, additional protective covers or labyrinth seals can be installed.

Preventive Replacement

Develop a replacement plan based on historical operation data to avoid sudden failures.

Optimize Operating Conditions

Avoid Overloading

It is prohibited to exceed the rated dynamic load of the bearing (refer to the bearing model manual).

For applications with impact loads, select needle roller bearings or self – aligning roller bearings that can withstand impacts.

Control the Rotational Speed

Avoid exceeding the maximum rotational speed of the bearing (for high – speed applications, light – series or ceramic bearings can be selected).

Environmental Control

In high – temperature environments: Strengthen heat dissipation (such as air cooling, oil cooling) or select high – temperature – resistant materials (such as silicon nitride ceramics).

In humid environments: Use bearings with anti – rust coatings or regularly apply anti – rust oil.

Common Misconceptions and Corrections

Misconception 1: The more lubrication, the better.

Correction: Excessive lubrication can cause the grease to agitate and generate heat, accelerating its aging.

Misconception 2: Tapping the outer ring with a hammer during installation.

Correction: Tapping the outer ring may cause the raceway to deform. Instead, apply pressure evenly to the inner ring.

Misconception 3: Ignoring slight abnormal noises.

Correction: Abnormal noises are early signs of malfunctions and need to be investigated immediately.

Supplier of Slewing Bearing

If you adopt this set of maintenance methods of mine, the lifespan of the bearings can be significantly extended. It’s no problem to extend it from the original 1 year to 3 – 5 years. This can not only reduce the cost of frequent bearing replacements, including the cost of purchasing new bearings and the labor cost for replacement, but also minimize the losses caused by equipment downtime due to failures. It can improve production efficiency and make your equipment operate more stably and reliably.I hope you can consider giving my methods a try. If you have any questions during the actual operation process, feel free to contact LDB Bearing at any time. I’m more than happy to help!

What is high-quality slew bearing?

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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

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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:

  1. 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.
  2. 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.
  3. Ball type slewing bearings: These use balls as rolling elements and are suitable for applications with lighter loads and moderate rotational speeds.
  4. Roller type slewing bearings: These use cylindrical or tapered rollers for heavier-duty applications, providing a higher load capacity than ball type bearings.
  5. 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:

  1. 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.
  2. Rotational speed: Consider the speed at which the bearing will rotate. Higher speeds might require bearings with lower friction and specialized materials.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.

Guide and overview of Four-Point Contact Ball Slew Bearing

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A four-point contact ball slew bearing is a type of rotational bearing designed to support large loads while providing smooth, reliable rotation. It is characterized by four points of contact between the steel balls and the bearing raceways, which allow it to carry both axial and radial loads as well as tilting moments. This feature makes the four-point contact ball slew bearing highly versatile for use in applications that require rotation and load support.

Types of Four-Point Contact Ball Slew Bearing

Single-row Four-Point Contact Ball Slew Bearing: This type has a single row of balls and is designed for lighter load applications.

Double-row Four-Point Contact Ball Slew Bearing: This type consists of two rows of balls, providing higher load-bearing capacity and better support for heavy-duty applications.

Crossed Roller Slew Bearing: Although not strictly a “ball” bearing, this type uses rollers arranged in a crisscross pattern and can support both axial and radial loads, making it suitable for similar applications.

Features of Four-Point Contact Ball Slew Bearing

Compact Design: The four-point contact configuration allows for a compact design, making it suitable for installations where space is limited.

High Load Capacity: It can carry radial, axial, and tilting loads simultaneously, making it suitable for applications with high load requirements.

Versatility: These bearings are designed to handle combined loads, including axial, radial, and moment loads, making them highly versatile.

Easy Installation: The compact size and simple structure make them easier to install in various mechanical systems.

Low Maintenance: Four-point contact ball slew bearings generally require minimal maintenance, making them cost-effective in the long term.

Applications of Four-Point Contact Ball Slew Bearing

Construction Machinery: Used in cranes, excavators, and other heavy equipment where rotation and load support are essential.

Renewable Energy: Applied in wind turbines to allow for the rotation of the turbine blades.

Automated Guided Vehicles (AGVs): Used in automated systems for handling heavy loads with rotation.

Solar Trackers: Enables the rotation of solar panels to follow the sun’s position.

Heavy Equipment: Used in other machinery, such as rotary tables, material handling systems, and industrial robots.

Tech Specs of Four-Point Contact Ball Slew Bearing

Load Capacity: Typically ranges from a few tons to several hundred tons, depending on the design and size.

Size: Can vary from small diameters (a few hundred millimeters) to very large diameters (several meters).

Material: High-strength steel is commonly used for the inner and outer rings, while ceramic or steel balls are often used for the rolling elements.

Bearing Configuration: Four-point contact ball bearings consist of two raceways and four points of contact between the balls and raceways.

Lubrication: Requires lubrication to reduce friction and wear; typically grease or oil is used.

Rotational Speed: Can support low to medium speeds depending on the load and application.

Operating Temperature: Typically operates within a range from -30°C to +120°C, though specialized materials can extend this range.

How to select four-point contact ball slew bearing?

Selecting a four-point contact ball slew bearing requires careful consideration of several factors to ensure that the bearing meets the requirements of your specific application. Here are the key steps to guide you in selecting the right bearing:

1. Determine the Load Requirements

Axial Load: The bearing must handle the axial load acting along the axis of rotation. Ensure the selected bearing can support the maximum axial load required for your application.

Radial Load: The bearing should also support radial loads that act perpendicular to the axis of rotation.

Tilting Moment (Moment Load): If your application involves tilting or turning, the bearing should handle the moment (torque) that may be applied to it.

2. Identify the Size and Dimensions

Inner and Outer Diameter: Choose a bearing with appropriate inner and outer diameters based on the space available in your machinery.

Height or Width: Ensure that the bearing’s height (or width) fits within the mechanical system’s design constraints.

Load Rating: Check the load rating (dynamic and static) provided by the bearing manufacturer to ensure it can handle the expected loads and moments during operation.

3. Consider Rotational Speed and Performance

Speed Requirements: Four-point contact ball slew bearings are generally used in low- to medium-speed applications. Consider the maximum speed at which the bearing will operate and check if the bearing can support this speed without excessive wear.

Friction and Efficiency: Lower friction bearings lead to more efficient rotation and less heat generation. Ensure the bearing type offers low friction for your application.

4. Material Selection

Raceway Material: High-strength materials like alloy steel or stainless steel are commonly used for raceways. Depending on the environmental conditions (such as exposure to corrosive elements), you may need to select stainless steel or other corrosion-resistant materials.

Ball Material: The balls are typically made of steel, ceramic, or a hybrid of both. Ceramic balls offer lower friction and better performance in harsh environments but are more expensive.

Lubrication: Depending on the environment, you may need a bearing that is pre-lubricated or one that can easily be lubricated with grease or oil. Ensure the bearing is compatible with the lubrication system.

5. Check for Environmental Conditions

Temperature Range: Consider the operating temperature range of the bearing. Standard bearings typically operate between -30°C and 120°C, but you may need special materials if your application requires operation in extreme temperatures.

Corrosion Resistance: In corrosive environments (such as offshore or chemical industries), you may need a bearing with enhanced corrosion resistance, such as stainless steel or a special coating.

Dust and Contaminant Resistance: Ensure the bearing has proper sealing or protection against dust, dirt, or other contaminants that could reduce its lifespan.

6. Bearing Configuration

Single Row vs. Double Row: Single-row bearings are suitable for lighter applications with moderate load requirements. Double-row bearings provide higher load capacity and are suitable for more demanding applications.

Sealing Type: Choose a bearing with appropriate seals if your application involves exposure to dirt, water, or chemicals.

Inner Ring or Outer Ring Rotation: Some bearings are designed for inner ring rotation, while others are for outer ring rotation. Consider which type of rotation is required in your application.

7. Design Considerations

Mounting and Alignment: Verify that the bearing is easy to mount and align properly. Poor alignment can lead to premature wear and failure.

Weight and Space Constraints: Ensure the bearing fits within the available space and meets any weight limitations in your system design.

8. Consider Service Life and Maintenance Needs

Maintenance Requirements: Choose a bearing that offers easy maintenance options, including the ability to monitor wear and replace seals or lubricants. Some bearings are designed for long service life with minimal maintenance.

Service Life (L10 Life): Check the L10 life (the point at which 90% of bearings will still be operational). A longer L10 life indicates better durability under load.

9. Manufacturer and Quality Standards

Reputation of Manufacturer: Select a reputable bearing manufacturer known for producing high-quality, reliable bearings.

Quality Certifications: Ensure the manufacturer adheres to industry standards (such as ISO, DIN) for quality control, as this ensures better reliability and performance of the bearing.

10. Cost-Effectiveness

Budget: While cost should not be the sole deciding factor, you should balance performance requirements with your budget constraints. Higher load ratings, specialized materials, and better seals will generally increase the cost of the bearing.

Supplier of four-point contact ball slew bearing

LDB Bearing is a professional slew bearing manufacturer provides high quality and long service life four point contact ball slew bearing for your needs in any project. If you are looking for four point contact ball slew bearing, feel free to contact us.

What is excavator slew bearing?

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What is Excavator Slew Bearing?

An excavator slew bearing, also known as a slewing ring or turntable bearing, is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slow-oscillating load. Slew bearings are engineered to handle simultaneous axial, radial, and moment loads. In excavators, these bearings are crucial as they enable the cab and the attached boom to rotate smoothly around the undercarriage without any hindrance.

Types of Excavators Slew Bearing

The types of slew bearings used in excavators can vary based on the design and requirements of the machinery. Common types include:

Single-row Four-point Contact Ball Bearing – This is the most common type, capable of handling axial and radial forces in both directions. It features a single row of balls with a gothic arch raceway design which allows for four points of contact with the balls, accommodating tilting moments efficiently.

Double-row Ball Slew Bearing – This design offers higher load capacities than single-row types by having two rows of rolling elements. It handles larger axial and radial loads and can support larger tilting moments.

Crossed Roller Slew Bearing – In this type, rollers are arranged in a crossed pattern, which provides higher stiffness and can carry higher loads than ball bearings. This type is ideal for applications requiring high precision and rigidity.

Three-row Roller Slew Bearing – This design incorporates three rows of rollers, which bear different loads separately, thus allowing for maximum load capacity in all directions. It’s suitable for heavy-duty applications where high load capacity is crucial.

Function of Excavator Slew Bearing

The primary function of an excavator slew bearing is to facilitate the rotation of the upper structure (cab, engine, boom, etc.) independently of the undercarriage. This bearing is critical for the following functions:

Rotation Capability: Allows 360-degree rotation of the upper part of the excavator, which is essential for tasks like digging and dumping without moving the base.

Load Handling: Supports axial, radial, and moment loads during the operation of the excavator.

Precision Movement: Ensures smooth and precise movement, which is crucial for operation efficiency and safety.

Applications of Slew Bearing

Slew bearings are not only used in excavators but also find applications in several other fields:

Cranes and Lifts: For rotation mechanisms in tower cranes, mobile cranes, and boom lifts.

Wind Turbines: In the yaw and pitch mechanisms that adjust the blades and orientation of the turbine.

Medical Equipment: In devices like CT scanners and medical chairs where precise and smooth rotation is required.

Robotic Arms and Manufacturing Equipment: For joints that require rotational movement.

How to Select Slew Bearing for Excavator?

Selecting the right slew bearing for an excavator involves several considerations:

Load Capacity: Determine the axial, radial, and moment loads the bearing needs to support.

Size and Space Constraints: Consider the physical dimensions available in the excavator design.

Precision and Rigidity Requirements: Depending on the application’s precision needs, choose between ball and roller bearings.

Environment and Service Life: Assess the environmental conditions (dust, temperature, moisture) and desired service life, which influence material and sealing choices.

Manufacturer and Technical Support: Opt for reliable manufacturers and ensure availability of technical support and replacement parts.

Selecting the appropriate slew bearing is crucial for ensuring the reliability, efficiency, and longevity of the excavator. Proper maintenance and regular inspection are also vital to maximize the lifespan and performance of slew bearings.

About LDB Bearing

LDB Bearing is a professional slewing bearing, slewing ring, slew drive and customize slew bearing manufacturer in China. If you are looking for excavator slew bearings, feel free to contact us.

What is a 4 point contact ball slew bearing?

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What is a 4-Point Contact Ball Slewing Bearing?

A 4-point contact ball slewing bearing is a specialized bearing that facilitates rotational movement between two parts of a machine, often supporting heavy loads while allowing for pivoting and rotating. It is characterized by its ability to accommodate axial, radial, and moment loads from any direction simultaneously. The “4-point” refers to the design where each ball contacts the raceway at four points, which optimizes load distribution and increases the bearing’s ability to handle various loads.

Types of 4-Point Contact Ball Slewing Bearings

Single Row Four-Point Contact Ball Bearings: The most common type, featuring a single row of balls with a gothic arch raceway. It provides compactness and high performance, suitable for light to medium load applications.

Double Row Four-Point Contact Ball Bearings: These have two rows of balls which can bear more weight and are suitable for applications requiring higher load capacity.

Flanged Type Four-Point Contact Ball Bearings: These bearings include flanges on the inner or outer rings, which can help in mounting and provide axial location.

Features of 4-Point Contact Ball Slewing Bearings

High Load Capacity: They can support higher loads in all directions compared to other types of bearings due to their unique contact geometry.

Compact Design: These bearings are designed to be compact, making them ideal for use in areas where space is limited.

Versatility: Suitable for both axial and radial loads and capable of handling tilting moments.

Smooth Rotation: Offers smooth and stable rotation, which is crucial for applications involving precision movement.

Ease of Maintenance: Some designs are made to be easily maintained, including options for lubrication which extend the lifespan of the bearing.

Applications of 4-Point Contact Ball Slewing Bearings

4-point contact ball slew bearings are used in a variety of applications, including:

Cranes and Lifts: For rotation of the boom, basket, or other lifting components.

Wind Turbines: In the yaw and pitch control mechanisms.

Medical Equipment: Particularly in advanced imaging devices like CT scanners and MRI machines.

Industrial Turntables: Used to rotate parts or entire assemblies within manufacturing setups.

Robotic Arms: Provides rotational movement and stability.

Marine Applications: Such as radar and satellite positioning systems.

How to Select 4-Point Contact Ball Slewing Bearings?

Selecting the right 4-point contact ball slewing bearing involves considering several factors:

Load Requirements: Determine the axial, radial, and moment loads the bearing will need to support.

Speed Requirements: Consider the operational speed of the bearing, as higher speeds may require specific design features to reduce friction and wear.

Environmental Conditions: Assess the environmental conditions such as temperature, presence of corrosive materials, and dust, which might affect the choice of materials and sealing options.

Size and Space Constraints: Evaluate the available space to ensure the bearing fits within the designated area.

Service Life and Maintenance: Consider the expected service life and ease of maintenance. Opt for bearings with features that facilitate long service life and ease of maintenance, such as lubrication ports.

Cost: Factor in the cost, not just in terms of initial purchase but also installation, maintenance, and potential downtime.

By carefully considering these factors, you can select a 4-point contact ball slewing bearing that meets the specific needs of your application, ensuring optimal performance and durability.

Four point contact ball slew bearing supplier

LDB Bearing is a professional four point contact ball slew bearing manufacturer provding high quality slew bearings, slew drives, and slew rings for industrial applications, if you are looking for four point contact ball slew bearing, feel free to contact us.

What is slew bearing?

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What is a Slew Ring Bearing?

A slew ring bearing, also known as a slewing ring or turntable bearing, is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slow-oscillating load, often a horizontal platform such as a conventional crane, a swing yarder, or the wind-facing platform of a horizontal-axis windmill. It consists of an inner ring and an outer ring, one of which usually incorporates a gear. Together with attachment holes in both rings, they enable an optimized power transmission with a simple and quick connection between adjacent machine components.

Types of Slew Ring Bearings

Slew ring bearings are categorized mainly based on their design and the demands of the application:

Single-row Four-point Contact Ball Bearing – This type is the most common, characterized by a single row of balls with the contact angle that can support axial, radial, and moment loads.

Double-row Ball Bearing – Offers higher load capacity than a single-row, using two rows of balls.

Crossed Roller Bearing – Rollers are arranged at right angles to each other at intervals between inner and outer rings. This design offers high stability and accuracy, suitable for high axial and radial loads.

Three-row Roller Bearing – This type combines three rows of rollers to bear different loads separately, facilitating higher load capacity and rigidity.

Ball and Roller Combination Bearing – These bearings combine both rollers and balls in different rows to optimize load capacity and reduce material costs.

Features of Slew Ring Bearings

High Load Capacity: Designed to handle simultaneously acting radial, axial, and moment loads.

Compactness: They are relatively thin in section and are often made in diameters of a meter or more; thus, they save space compared to conventional bearings.

Rotation Accuracy: Provides precise rotation and positioning.

Ease of Mounting: Their design simplifies the structure of the installation equipment.

Integrated Gearing: Many slew bearings have internal or external gears, facilitating the integration into a system.

Applications of Slew Ring Bearings

Slew bearings are used in a variety of applications including:

Construction machinery like cranes and excavators.

Wind turbines.

Medical equipment, particularly in rotating tables and scanners.

Military applications, such as in radar and missile launchers.

Industrial turntables and manipulators.

Robotics and automation systems.

Price of Slew Ring Bearings

The price of slew ring bearings can vary widely depending on the size, type, material, and specific manufacturer requirements. Small, standard slew bearings might start around a few hundred US dollars, while large, custom-engineered bearings can cost several thousand or even tens of thousands of dollars.

How to Select Slew Ring Bearings?

Selecting the appropriate slew ring bearing involves several considerations:

Load Type and Magnitude: Determine the axial, radial, and moment loads the bearing will need to support.

Precision Requirements: Consider the required precision and rotational speed.

Environmental Conditions: Assess the operating environment, including temperature extremes and exposure to contaminants or corrosive elements.

Size and Space Constraints: Factor in the physical space available for the bearing.

Gear Requirements: Decide if internal or external gearing is necessary for your application.

Material and Coatings: Choose materials and coatings based on environmental and load conditions to enhance durability and performance.

Lifecycle and Maintenance: Consider the expected life and maintenance requirements, including lubrication and inspection intervals.

By understanding these factors, engineers can select the most appropriate slew ring bearing for their specific application, balancing performance, longevity, and cost.

LDB Bearing is a professional slewing bearing manufactuer offers high-quality, custom-tailored slew bearings, slewing drives and gears for your project.

What are slew drives used for?

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What is Slew Drive?

A slew drive is a ready-to-install unit used to control the movement of a structure in a rotational manner. It consists of a motor, a gear, and a slew bearing, which enables it to handle both radial and axial loads, as well as tilting moments. Slew drives are designed to provide precise control over the rotation and positioning of a component and are known for their robustness and reliability.

Types of Slew Drive

Slew drives can be categorized based on several factors, including the type of gears used, the configuration of the drive, and the application. The most common types are:

  1. Worm Gear Slew Drives: These use a worm (a threaded cylinder) and a worm wheel (a gear with teeth that mesh with the worm). This type allows for high torque and reduction ratios, making it suitable for applications requiring slow and powerful rotations.
  2. Spur Gear Slew Drives: These involve spur gears and are typically used for applications requiring higher speed but lower torque compared to worm gear drives.
  3. Helical Gear Slew Drives: Similar to spur gears but with angled teeth, helical gears provide smoother and quieter operation with more load capacity.
  4. Dual Axis Slew Drives: These are designed to support movements around two perpendicular axes simultaneously, ideal for more complex rotations and positioning tasks.

Features of Slew Drive

  • High Load Capacity: Slew drives can handle significant radial, axial, and moment loads, making them suitable for heavy-duty applications.
  • Precision: They provide precise control over movement, crucial for applications like solar tracking and robotics.
  • Compact Design: Integrating the bearing and gear in one unit saves space and simplifies installation.
  • Versatility: They can be customized with different motors (hydraulic, electric, etc.) and sensors for various applications.
  • Robustness: Designed to withstand harsh environments, including outdoor and heavy industrial settings.

What are Slew Drives Used For?

Slew drives are used in a variety of applications, including:

  • Solar Trackers: To adjust panels to follow the sun’s movement, maximizing energy absorption.
  • Wind Turbines: To position the nacelle and blades for optimal wind engagement.
  • Cranes and Manlifts: For precise positioning of the boom and other components.
  • Rotary Tables: In manufacturing and assembly processes.
  • Satellite Dishes: To accurately position dishes for optimal signal reception.

How to Select Slew Drive

Selecting the right slew drive involves several considerations:

  1. Load Requirements: Assess the radial, axial, and moment loads the drive must support.
  2. Speed Requirements: Determine the necessary speed of rotation.
  3. Precision and Backlash: Consider the required precision and acceptable backlash.
  4. Environment: Take into account the environmental conditions (e.g., temperature, exposure to elements).
  5. Power Source: Decide on the type of motor or power source (electric, hydraulic, etc.).
  6. Size and Space Constraints: Ensure the selected slew drive fits within the available space.

Slew Drive Maintenance

Maintaining a slew drive is crucial for ensuring longevity and reliability:

  • Regular Lubrication: Ensure gears and bearings are adequately lubricated according to the manufacturer’s specifications.
  • Inspection and Cleaning: Regularly inspect and clean the slew drive to prevent dirt and debris build-up, which can lead to premature wear.
  • Check for Wear and Tear: Regularly inspect for signs of wear or damage, particularly in the gears and bearings.
  • Follow Manufacturer’s Guidelines: Adhere to the maintenance schedule and guidelines provided by the manufacturer to ensure optimal performance.

Slew drive supplier

LDB Bearing is a professional slew drive manufacturer providing high quality and price competitive slew drive and slew bearings for many applications such as solar tracker, vacuum pump trucks, excavators, manlift and more. Feel free to contact us if you are looking for slew drive for your projects.

What is excavator slew ring？

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An excavator slew ring, also known as a slewing bearing or turntable bearing, is a crucial component in the construction of excavators. It is a rotational rolling-element bearing that typically supports a heavy but slow-turning or slow-oscillating load, often a horizontal platform such as a conventional crane, a swing yarder, or the wind-facing platform of a horizontal-axis windmill.

Features of Excavator Slew Ring

  1. High Load Capacity: Slew rings are designed to withstand axial, radial, and moment loads, making them suitable for the heavy loads and complex load combinations experienced by excavators.
  2. 360-degree Rotation: They enable the excavator’s upper structure (including the cab and boom) to rotate fully relative to the undercarriage.
  3. Compact Design: Despite their load-bearing capabilities, slew rings are relatively compact and integrate seamlessly into the excavator’s design.
  4. Sealed and Lubricated: They are generally sealed to prevent dirt, debris, and water ingress and are pre-lubricated for long life and reduced maintenance.
  5. Durability and Reliability: Made from robust materials, slew rings are built to withstand harsh working environments and repetitive use.

Types of Excavator Slew Ring

  1. Single-row Ball Type: Features a single row of steel balls. It’s the most common type, suitable for light to medium loads and offers smooth rotation.
  2. Double-row Ball Type: Contains two rows of balls, which can handle larger loads than the single-row type and provide better stability and load distribution.
  3. Crossed Roller Type: Rollers are arranged in a crossed pattern to increase load capacity and rotational accuracy. Ideal for applications requiring high precision under high loads.
  4. Three-row Roller Type: This type has three rows of rollers, maximizing load capacity and stiffness. It’s used for very heavy-duty applications.

Standards of Excavator Slew Ring

Slew rings are manufactured according to various international standards to ensure quality, compatibility, and safety. Some common standards include:

  1. ISO 9001: Quality management systems standards that help ensure manufacturers meet the needs of customers and other stakeholders.
  2. ISO 14001: Pertains to effective environmental management systems.
  3. JIS (Japanese Industrial Standards) and DIN (Deutsches Institut für Normung): Specific standards that provide guidelines on dimensions, tolerances, load capacities, and material properties.

How to Select Slew Ring for Excavators？

Selecting the right slew ring for an excavator involves several considerations:

  1. Load Calculations: Understand the maximum loads the slew ring will need to support. This includes axial, radial, and moment loads.
  2. Size and Space Constraints: The size of the slew ring must fit within the excavator’s designated space without interfering with other components.
  3. Sealing and Lubrication: Depending on the operating environment, choose a slew ring with appropriate sealing and lubrication for optimal performance and durability.
  4. Material and Coatings: Select materials and coatings that can withstand the environmental conditions (e.g., corrosion-resistant coatings if used in marine environments).
  5. Manufacturer’s Reputation and Support: Choose a manufacturer known for quality and reliability, and ensure they offer adequate technical support and warranty.
  6. Rotation Requirements: Consider the required rotational speed and precision, which will affect the choice between ball and roller types.

By carefully considering these factors, you can ensure that the chosen slew ring will meet the operational demands of the excavator and provide long service life.

Excavator Slew Ring Manufacturer

LDB Bearings is a professional slew ring, slew bearing, and slew drive manufactuer provides high quality and cost effective slew rings for excavator, if you are looking for slewing ring for excavator, feel free to contact us.