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How to Distinguish Bearings of Different Precision Levels

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Precision grades are established according to ISO standards. However, due to variations in national standards, their nomenclature may differ significantly.

The precision grades of bearings are primarily classified based on dimensional accuracy and rotational accuracy. These grades are standardized into six levels: 0, 6X, 6, 5, 4, and 2, with precision increasing sequentially from grade 0. Details are as follows:

  • Grade 0: Widely used in general bearing systems with rotational accuracy greater than 10 μm, such as gearboxes and feed mechanisms in ordinary machine tools, automotive and tractor transmissions, general-purpose motors, pumps, and agricultural machinery.
  • Grades 6 and 5: Suitable for bearing systems requiring rotational accuracy between 5–10 μm or higher speeds, such as the front support (grade 5) and rear support (grade 6) of lathes, precision instruments, and high-precision rotating mechanisms.
  • Grades 4 and 2: Used in ultra-precision systems with rotational accuracy below 5 μm or extremely high speeds, such as precision coordinate boring machines, gear systems in precision grinders, high-precision instruments, and high-speed cameras.
    Application Scenarios for Different Bearing Types by Precision Grade
    Deep Groove Ball Bearings
  • P0: General industrial equipment (e.g., motors, fans, pumps, reducers) with low precision and speed requirements. P6: Automotive engines, wind turbines, precision pumps—suitable for moderate speed and precision. P5 and above High-speed turbines, industrial robots, and other high-speed, precision equipment.
    Angular Contact Ball Bearings
    P0: Ordinary rotating mechanisms with low precision demands.P6: Machine tool spindles, high-speed motors—enhances precision.P5: Precision machine tools, optical instruments—ensures high rotational accuracy and rigidity. P4 and above: Aerospace, semiconductor manufacturing—extremely high precision and speed.
    Self-Aligning Ball Bearings
  • P0: Motors, agricultural machinery, automotive transmissions—tolerates moderate misalignment.P6 and above**: Precision instruments requiring stability.

Self-Aligning Roller Bearings

  • P0: Heavy machinery (e.g., crushers, vibrating screens, paper mills)—handles large radial and axial loads.P6 and above: High-precision equipment (e.g., rolling mills)—ensures stability and reliability.
    Tapered Roller Bearings
  • P0: Automotive transmissions, rear axles, general engineering machinery.P6: Machine tool feed systems with moderate precision needs. P5 and above: Aerospace, precision machine tool spindles—high precision and load capacity.
    Cylindrical Roller Bearings
  • P0: Industrial conveyors (e.g., belt conveyor rollers).P6 and above: High-precision grinding machine spindles, CNC machine lead screw supports.
    Thrust Ball Bearings
  • P0 Low axial load applications (e.g., small power tools). P6 and above: Precision lathe lead screws—high axial accuracy.
    Thrust Roller Bearings
  • P0: Heavy machinery (e.g., cranes, rolling mills)—axial support.P6 and above**: Aerospace engines, precision coordinate boring machines—extreme axial accuracy and load capacity.
    Impact of Bearing Precision Grade
    Performance Effects
  • Rotational Accuracy: Higher grades reduce rotational runout (e.g., high-precision spindles in machine tools).
  • Friction Characteristics: Smoother surfaces and tighter tolerances minimize friction and heat, ideal for high-speed systems.
  • Stiffness: Enhanced dimensional accuracy ensures stable stiffness (e.g., aerospace engine bearings).
    Lifespan Effects
  • Load Distribution: Higher precision reduces stress concentration, extending lifespan (e.g., large motors).
  • Wear and Fatigue Reduced sliding and friction slow wear and fatigue (e.g., precision grinder spindles).
  • Sealing and Lubrication: Tight tolerances improve sealing and lubrication retention, prolonging service life.
    When selecting bearings, there are the following considerations:
    Lubrication and Heat Dissipation: For high-speed rotating bearings, in addition to choosing the appropriate bearing type, the lubrication method and heat dissipation measures need to be considered. For example, using mist lubrication or jet lubrication can effectively reduce the temperature of high-speed bearings. At the same time, selecting a lubricating oil with low viscosity and high flash point also helps to reduce heat generated by friction.
    Accuracy Matching: When selecting the bearing accuracy, it should be matched with the overall accuracy requirements of the equipment. For example, in a high-precision grinder, the spindle bearing needs to be selected with P4 class or higher accuracy, while the feed shaft bearing may meet the requirements with P5 or P6 class.
    Application Scenarios: Self-aligning bearings are often used in situations where it is difficult to ensure the coaxiality of the two bearing seat holes, such as long shaft transmissions and equipment with unstable installation bases. In large mechanical equipment such as mining machinery and metallurgical equipment, self-aligning roller bearings are widely used, which can effectively compensate for the shaft deflection caused by equipment deformation or installation errors. Working Environment
  • Temperature Range: Determine the ambient temperature range in which the bearing operates. For high-temperature environments, select high-temperature-resistant bearing materials such as ceramic ball bearings and special alloy bearings, and use high-temperature-resistant grease. For low-temperature environments, choose grease with good low-temperature performance to ensure good lubrication and starting performance of the bearing at low temperatures.
  • Chemical Corrosion: In environments with chemical corrosive media, such as in the chemical and electroplating industries, select stainless steel bearings or bearings with anti-corrosion surface treatment, and use anti-corrosion grease. In addition, sealing measures can be taken to prevent corrosive media from entering the bearing interior.
    Price of Bearings by Precision Grade
    Prices vary based on type, brand, and specifications. For example: Deep Groove Ball Bearings: P0 (lowest cost) to higher grades (more expensive). Angular Contact Ball Bearings: Higher precision grades incur higher costs due to manufacturing complexity. Imported brands, special materials, and large-sized bearings also command premium pricing.
    For purchasing guidance, consult LDB-Bearing, a supplier offering diverse bearing types (e.g., slewing rings, cross roller bearings, cylindrical roller bearings). Consider application-specific requirements (e.g., construction machinery, wind energy, automotive) to determine the optimal bearing type, size, and precision grade.

Why is Bearing Installation So Important?

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Why is Bearing Installation So Important?

The importance of bearing installation lies in its direct relation to the operating accuracy, stability, reliability, and service life of mechanical equipment. Improper installation may lead to frequent equipment failures and even premature scrapping.

The importance of bearing installation.

As a crucial component of mechanical equipment, the installation quality of bearings is of utmost importance. Precise installation is the cornerstone for ensuring the efficient and stable operation of equipment. It can guarantee high-precision during mechanical operation, enabling all components of the equipment to work in harmony and fit seamlessly. If there are installation deviations, it will not only cause abnormal vibrations and noises but also exacerbate component wear, resulting in a significant increase in energy consumption and a substantial reduction in equipment stability. Moreover, improper installation can easily cause failures, shorten the service life of the equipment, increase maintenance costs and downtime, and bring serious losses to production. Therefore, standardized and scientific bearing installation is a necessary condition for achieving good equipment performance and ensuring the orderly progress of production.

Precautions During Bearing Installation

Preparation Before Installation

– Inspect Parts: Check the dimensional accuracy, form accuracy, and surface quality of the bearings and related parts to ensure there are no defects or damages. At the same time, confirm that the dimensions, shapes, and surface roughness of the journal and housing bore that cooperate with the bearing meet the requirements.

– Clean Parts: Use a clean cloth or special cleaning agent to thoroughly remove oil stains, iron filings, dust, and other impurities from the surfaces of the bearing, journal, housing bore, etc., to prevent impurities from entering the bearing and affecting its performance and life.

– Prepare Tools: Prepare appropriate installation tools, such as presses, sleeves, hammers, pullers, etc. Avoid directly hitting the bearing with a hand hammer to prevent damage to the bearing.

Installation Proces

– Fit Selection: Select the appropriate fit method according to the type, size, and working conditions of the bearing. For interference fits, the hot installation or cold installation method can be used. In hot installation, the bearing is heated to an appropriate temperature to expand its inner diameter and then sleeved onto the journal. In cold installation, the journal is cooled to reduce its size and then inserted into the inner hole of the bearing.

– Installation Direction: For bearings with direction requirements, such as angular contact ball bearings and tapered roller bearings, they must be installed in the correct direction to ensure that the bearings can withstand loads normally.

– Installation Accuracy: Ensure the installation accuracy of the bearing during installation, and make sure that the coaxiality and perpendicularity of the bearing with the journal and housing bore meet the requirements. For high-precision bearings, such as machine tool spindle bearings, the installation accuracy requirements are even higher, and professional measuring tools are required for inspection and adjustment.

Inspection After Installation

– Clearance Inspection: After installation, check the clearance of the bearing to ensure it is within the specified range. Excessive or too small clearance will affect the performance and life of the bearing.

– Lubrication and Sealing: Select the appropriate lubricant and ensure that the bearing is well lubricated. At the same time, install an effective sealing device to prevent lubricant leakage and the entry of external impurities into the bearing.

– Operation Inspection: During the trial operation stage of the equipment, closely observe the operation of the bearing, including temperature, noise, vibration, etc. If any abnormalities are found, stop the machine in time for inspection, identify the cause, and take measures.

Common Installation Faults of Bearings

Incomplete Installation

– Manifestation: The bearing is not fully installed in the designated position, resulting in a gap between the inner or outer ring and the shaft shoulder or housing bore shoulder, and they are not closely fitted.

– Consequences: The bearing will bear uneven loads during operation, generating additional stress and deformation, accelerating the wear and fatigue of the bearing, reducing its service life, and in severe cases, may lead to bearing failure.

– Causes: Improper use of installation tools, uneven installation force, insufficient dimensional accuracy of the shaft or housing, etc.

Improper Fit

– Manifestation: An overly tight interference fit causes the inner ring of the bearing to expand or the outer ring to shrink, changing the original clearance of the bearing. An overly loose fit causes the bearing to slide relative to the shaft or in the housing bore.

– Consequences: An overly tight fit will increase the friction and heat generation of the bearing, affecting its normal operation and may even cause the bearing to seize. An overly loose fit will make the bearing operation unstable, generating vibrations and noises, and also exacerbate the wear between the bearing and the mating surface.

– Causes: Inaccurate selection and calculation of the fit tolerance, and excessive dimensional deviations of the journal or housing bore due to insufficient processing accuracy.

Damage During Installation

– Manifestation: Scratches, dents, cracks, and other damages occur on the raceway, rolling elements, or cages of the bearing.

– Consequences: It damages the surface quality and accuracy of the bearing, causing abnormal noises and vibrations during the bearing’s operation, reducing its load-carrying capacity and service life. Severe damage may lead to immediate bearing failure.

– Causes: Using improper tools to directly hit the bearing during the installation process or colliding with other parts during the assembly process.

Sealing Problems

– Manifestation: The sealing device is installed incorrectly or the seal is damaged, resulting in lubricating oil leakage or the entry of external dust, moisture, and other impurities into the bearing.

– Consequences: Lubricating oil leakage will prevent the bearing from being well lubricated, exacerbating wear. The entry of impurities into the bearing will contaminate the grease, increase friction, accelerate the wear and corrosion of the bearing, and reduce its performance and life.

– Causes: Poor quality of the seal, damage to the seal during installation, inappropriate dimensions of the seal groove, etc.

Lubrication Problems

– Manifestation: Excessive or insufficient application of grease, improper selection of the viscosity of the lubricating oil, or insufficient cleanliness of the lubricating oil.

– Consequences: Excessive grease will cause excessive heat generation during the bearing’s operation, affecting heat dissipation. Insufficient grease cannot form a good oil film, increasing friction. Inappropriate viscosity will affect the lubrication effect, and insufficient cleanliness will allow impurities to enter the bearing, accelerating wear.

– Causes: Insufficient understanding of the bearing’s lubrication requirements, unreasonable design of the lubrication system, or lack of attention to cleanliness when adding lubricating oil.

The price of production assemble.

Bearings of different types and specifications have different prices and installation difficulties. For example, deep groove ball bearings are relatively easy to install, while tapered roller bearings usually need to be installed in pairs and have their clearances adjusted, which is more difficult and results in higher labor costs. The installation cost of small bearings is relatively low, while that of large or special – specification bearings is higher. In economically developed regions and large cities, due to high labor costs and rents, the installation price will also be on the high side; in small and medium – sized cities and economically underdeveloped regions, the price is relatively lower.LDB-Bearing will give you best service.

What is the function of spur gears?

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Features of Spur Gears

Spur gear rotation is a mechanical transmission method that transmits power through the meshing of straight gears. It features a simple structure, low manufacturing and maintenance costs, high transmission efficiency (up to 98% – 99%), and a constant speed ratio. It is suitable for transmission between parallel shafts. Its advantages include high reliability, strong load – bearing capacity, and it is suitable for precise speed and position control. However, it may generate significant noise and impact during high – speed operation, and is only applicable to parallel – shaft transmission, not to crossed or staggered shafts. Spur gear rotation is widely used in fields such as mechanical equipment, the automotive industry, household appliances, and industrial robots.

Spur gears (straight gears) are one of the most common and widely used types of gears in mechanical transmission. Their teeth are parallel to the axis, and they have the characteristics of a simple structure, easy manufacturing, low cost, and high transmission efficiency (up to 98% – 99%). Spur gears are mainly used for power transmission and motion control between parallel shafts. The following are their detailed application fields and specific scenarios:

 Mechanical Equipment

– Machine Tools: Spur gears are used in the transmission system to achieve precise speed control and power transmission for components such as the main shaft and feed shaft, ensuring machining accuracy.

– Conveyor Belts: In production lines and logistics systems, spur gears drive the operation of conveyor belts to achieve continuous material transportation.

– Printing Machines: Spur gears are used to synchronize the movement of printing rollers, ensuring the accurate alignment of printed patterns.

– Pumps and Compressors: In fluid equipment, spur gears are used to transmit power and drive the operation of pumps or compressors.

Automotive Industry

– Transmissions: Spur gears are used in manual and automatic transmissions. Different combinations of gears with various numbers of teeth enable multi – gear shifting functions.

– Differentials: When a vehicle turns, spur gears help the left and right wheels achieve different rotational speeds, preventing tire skidding.

– Starter Motors: Spur gears mesh with the engine flywheel to start the engine.

– Steering Systems: In some mechanical steering systems, spur gears are used to transmit steering force.

 Household Appliances

– Washing Machines: Spur gears are used to drive the rotation of the washing tub and the spin – drying tub, realizing washing and spin – drying functions.

– Clocks: In mechanical clocks, spur gears are used to accurately transmit time and control the movement of the hands.

– Power Tools: Such as electric drills, chain saws, and blenders. Spur gears are used to transmit the power of the motor and drive the rotation of the tool head.

– Kitchen Appliances: In food processors and blenders, for example, spur gears are used to drive the blades or agitators.

 Industrial Robots

– Joint Transmission: Spur gears are used for the precise motion control of robot joints, ensuring the flexibility and accuracy of the robotic arm.

– Automation Equipment: In automated production lines, spur gears are used to achieve synchronous motion and power transmission, such as in assembly machines and packaging equipment.

Wind Power Generation

– Gearboxes: In wind turbines, spur gears are used to increase the low – speed rotation of the wind turbine blades to the high speed required by the generator, improving power generation efficiency.

Agricultural Machinery

– Tractors: Spur gears are used in the transmission system and power take – off devices to drive the wheels and agricultural implements.

– Harvesters: Spur gears are used to drive the cutting device and conveyor belt, realizing the harvesting and transportation of crops.

– Irrigation Equipment: In irrigation pumps and transmission systems, spur gears are used to transmit power.

 Aerospace

– Auxiliary Equipment: In aircraft and spacecraft, spur gears are used in the transmission devices of fuel pumps, hydraulic systems, and landing gears to ensure the reliable operation of the equipment.

– Engine Accessories: In the accessory drive system of aircraft engines, spur gears are used to drive components such as generators and fuel pumps.

 Heavy Machinery

– Cranes: Spur gears are used to drive the lifting mechanism and traveling mechanism, realizing the lifting and movement of heavy objects.

– Excavators: Spur gears are used to drive the movement of the crawler and the digging arm, ensuring the flexibility and power of the equipment.

– Engineering Vehicles: In bulldozers and loaders, for example, spur gears are used in the transmission system and power output.

Other Fields

– Medical Equipment: In medical machinery (such as operating tables and imaging equipment), spur gears are used for precise motion control.

– Office Equipment: In printers and copiers, spur gears are used to drive the paper feed and the movement of the print head.

– Watchmaking: In mechanical clocks and watches, spur gears are used for accurate time transmission.

Advantages of Spur Gears

Simple Structure: Easy to design, manufacture, and install.Low Cost: Compared with other gear types (such as helical gears or bevel gears), the manufacturing cost of spur gears is lower.Efficient Transmission: High transmission efficiency with low energy loss.Strong Reliability: Suitable for various industrial applications with stable performance.Precise Speed Ratio: Capable of achieving precise speed and position control.

Limitations of Spur Gears

Noisy: Prone to impact and noise during high – speed operation.Only Applicable to Parallel Shafts: Cannot be used for crossed – shaft or staggered – shaft transmission.Tooth Surface Wear: Long – term use may lead to tooth surface wear, requiring regular maintenance.

Price of Spur Gears Due to their wide range of application scenarios and reliable performance, spur gears have become an essential component in mechanical transmission. Through reasonable design, material selection, and lubrication maintenance, their advantages can be fully utilized, and their service life can be extended. LDB-Bearing will provide you with the best – quality service and offer you the most reasonable prices.

Applications of Bearings in the Industrial Field

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What is slew drive

Slew drive is a kind of slewing drive device, which has the characteristics of high load capacity, high precision, compact design, good sealing performance, high integration degree, convenient installation and maintenance, large transmission ratio, and high safety. It can play an important role in a variety of different industrial fields and equipment, achieving precise rotary motion and reliable load support.

Electric Motors and Generators

– Application: Bearings are used in electric motors and generators to support the rotor, reduce friction, and ensure smooth rotation.

– Types: Deep groove ball bearings, cylindrical roller bearings, angular contact ball bearings, etc.

– Features: High speed, low noise, long service life.

Pumps and Compressors

-Application: Bearings are used to support the rotating components of pumps and compressors, and they bear radial and axial loads.

– Types: Deep groove ball bearings, tapered roller bearings, thrust ball bearings, etc.

– Features: High temperature resistance, corrosion resistance, high load capacity.

Fans and Blowers

– Application: Bearings are used to support the fan shaft, ensuring smooth rotation and efficient operation.

– Types: Deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, etc.

– Features: Low friction, low noise, long service life.

Machine Tools and Machining Centers

– Application: Bearings are used to support spindles, lead screws, and guide rails, ensuring high-precision machining.

– Types: Angular contact ball bearings, cylindrical roller bearings, thrust ball bearings, etc.

– Features: High precision, high rigidity, high speed.

Conveyors and Belt Systems

– Application: Bearings are used to support the rollers and drive shafts of conveyors, ensuring smooth operation.

– Types: Deep groove ball bearings, self-aligning ball bearings, tapered roller bearings, etc.

– Features: High load capacity, impact resistance, long service life.

Heavy Machinery

– Application: Bearings are used to support rotating components in heavy machinery such as excavators, cranes, and bulldozers.

– Types: Tapered roller bearings, spherical roller bearings, cylindrical roller bearings, etc.

– Features: High load capacity, impact resistance, wear resistance.

Mining Machinery

– Application: Bearings are used to support rotating components in mining machinery such as crushers, ball mills, and screening machines.

– Types: Spherical roller bearings, cylindrical roller bearings, tapered roller bearings, etc.

– Features: High load capacity, impact resistance, wear resistance.

Paper Machinery

– Application: Bearings are used to support rotating components in paper machinery such as rollers, calenders, and winders.

– Types: Cylindrical roller bearings, spherical roller bearings, angular contact ball bearings, etc.

– Features: High temperature resistance, corrosion resistance, high precision.

Food and Beverage Machinery

– Application: Bearings are used to support rotating components in food and beverage machinery such as mixers, fillers, and packaging machines.

– Types: Stainless steel bearings, food-grade grease bearings, etc.

– Features: Corrosion resistance, compliance with food safety standards.

Textile Machinery

– Application: Bearings are used to support rotating components in textile machinery such as spinning machines, weaving machines, and winding machines.

– Types: Deep groove ball bearings, cylindrical roller bearings, angular contact ball bearings, etc.

– Features: High speed, low noise, long service life.

Steel and Metallurgical Equipment

– Application: Bearings are used to support rotating components in steel and metallurgical equipment such as rolling mills, continuous casters, and blast furnaces.

– Types: Tapered roller bearings, spherical roller bearings, cylindrical roller bearings, etc.

– Features: High temperature resistance, high load capacity, wear resistance.

Chemical Equipment

– Application: Bearings are used to support rotating components in chemical equipment such as agitators, centrifuges, and pumps.

– Types: Stainless steel bearings, corrosion-resistant bearings, etc.

– Features: Corrosion resistance, high temperature resistance, long service life.

Energy Equipment

– Application: Bearings are used to support rotating components in energy equipment such as wind turbines, hydro turbines, and gas turbines.

– Types: Tapered roller bearings, spherical roller bearings, cylindrical roller bearings, etc.

– Features: High load capacity, high temperature resistance, long service life.

Automation Equipment

– Application: Bearings are used to support rotating components in automation equipment such as robots, conveyors, and assembly lines.

– Types: Deep groove ball bearings, angular contact ball bearings, linear bearings, etc.

– Features: High precision, low noise, long service life.

Bearings have a wide range of applications in the industrial field, covering almost all mechanical equipment that requires rotational or linear motion. Different types of bearings have different characteristics and are suitable for various working conditions and application scenarios. Proper selection and use of bearings can significantly improve equipment efficiency, extend service life, and reduce maintenance costs.

Slew drive of LDB Bearing have an extremely high load capacity and can easily handle all kinds of heavy-duty operations. Even in harsh working conditions, it is no problem at all. Thanks to its compact design, you don’t have to worry about limited space during installation and can flexibly arrange it in narrow areas. Moreover, it has extremely high precision, ensuring stable operation of the equipment and accurate positioning, which greatly improves the quality of the work. With a high degree of integration, its installation and maintenance are simple and convenient, saving you a lot of time and cost. Its advantage of a large transmission ratio enables efficient power transmission, helping you easily achieve the desired rotational speed. Additionally, it has excellent sealing performance and safety features, allowing you to be fearless in harsh environments and ensuring worry-free and safe operation.

What is a Double Row Ball Slew Bearing?

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It features 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.   

Basic Structure 

– 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.

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.