What is a hybrid ceramic ball bearing?
Hybrid ceramic ball bearings are composite precision rolling bearings with metal inner and outer rings and rolling elements (steel balls replaced with ceramic balls), which are different from all steel bearings with inner and outer rings and steel balls, and all ceramic bearings with inner and outer rings and ball bearings. It perfectly combines the high toughness, impact resistance, easy processing and assembly of metal rings with the dual advantages of low-density, high rigidity, low friction, insulation and corrosion resistance, and high temperature resistance of ceramic balls. It is the preferred high-end bearing for high-speed, high-precision, and special working conditions, and is currently the most widely used ceramic bearing category in industrial mass production.
Vacuum pump, Servo motor, High speed fan, high-speed spindles etc, we use a design of bearing steel rings and silicon nitride ceramic balls. And For semiconductor, food and beverage, medical and pharmaceutical industries that require strict working conditions such as vacuum, clean space, and sterility, we generally use stainless steel and high nitrogen stainless steel materials such as 440C, X40, Cronidur 30, etc.
What is the overall structure and component composition of hybrid ceramic ball bearings?
The structural form of hybrid ceramic ball bearings is completely consistent with standard deep groove ball bearings/angular contact ball bearings, consisting of five core components and auxiliary sealing and lubrication components:
Core sports load-bearing structure
• Inner ring: interference fit with the main shaft, rotating synchronously with the shaft, and the inner raceway is in precise contact with the ceramic ball.
• Outer ring: fixed and matched with the bearing seat, stationary, with ceramic ball rolling guidance on the outer raceway.
• Ceramic rolling element (ceramic ball): a differentiated component of the bearing core, evenly distributed between the inner and outer raceway, which transmits loads and reduces friction during rolling. Generally, we use silicon nitride ceramic balls, which are suitable for special working conditions we choose zirconia ceramic balls and silicon carbide ceramic balls.
• Retainer & Cage: evenly partition ceramic balls to avoid collision and friction between them, ensuring smooth operation and even clearance
• Rolling contact clearance: Precise control of the clearance between the inner and outer rings and ceramic balls, suitable for high-speed, high-precision, and temperature rise working conditions. We will use stamped steel as the material for the retainer according to the actual working conditions PEEK. PTFE. 304 stainless steel PA66, PA6, PI and other materials.
Auxiliary sealing and protective components
• Dust cover (ZZ metal seal), sealing ring (2RS rubber seal): isolate dust, water vapor, impurities and other protective bearing chambers, lock internal lubricating grease,
• Lubricating medium: High speed precision special high-temperature low-noise lubricating grease, reducing the friction between metal and ceramic balls
Detailed material selection and performance characteristics of various components of hybrid ceramic ball bearings
The inner and outer rings are made of bearing steel and stainless steel, which can be matched with the working conditions as needed
• High carbon chromium bearing steel GCr15: Universal high-precision standard, hardness HRC61~65, strong wear resistance, easy to polish raceway accuracy, excellent rigidity, suitable for machine tools, servo motors, high-speed spindles, and conventional precision scenarios
• Stainless steel 440C/316L: rust proof, acid and alkali resistant, suitable for medical food, chemical humid, seawater, clean and sterile working conditions, 440C hardness close to bearing steel, 316L ultimate corrosion resistance
2. Ceramic rolling element materials include silicon nitride, zirconia ZrO₂, and silicon carbide, with silicon nitride being the preferred choice for high-precision and high-speed applications.
(1) Silicon nitride Si3N4 (preferred for ultra high precision)
• With a density only 40% of steel balls, it is extremely lightweight and significantly reduces high-speed centrifugal force
• The elastic modulus is 50% higher than that of steel, with high rigidity and minimal deformation under stress
• The coefficient of thermal expansion is only 1/4 of that of steel, with extremely stable dimensions at high temperatures and lower temperature rise
• Insulation, non-magnetic, low friction coefficient, self-lubricating, wear-resistant, failure is gradual peeling, high safety
• Hardness HRA ≥ 90, high temperature resistance and fatigue life far exceed steel balls
Zirconia ZrO2 has better toughness than silicon nitride, better impact resistance, and lower cost; Disadvantages: General high temperature stability, easy brittleness and fragmentation, mostly used for low-speed anti-corrosion and precision civilian scenarios.
Cage material (high-precision specialized)
• PEEK: high temperature resistance, high strength, low friction, wear resistance and anti-aging, high-speed spindle, servo motor ultra-high precision standard configuration
• PA66 nylon: lightweight, shock absorption and noise reduction, high cost-effectiveness, universal high-speed motor
• Phenolic resin, brass, stainless steel: special for high temperature, heavy load, strong corrosion and special working conditions
Sealing and lubricating materials
• Sealing: Nitrile rubber, fluorine rubber, stainless steel dust cover, resistant to high and low temperatures, and corrosion-resistant
• Lubrication: High speed and long-life lithium based grease, ceramic specific synthetic grease, suitable for ceramic metal heterogeneous friction, reducing adhesive wear
Precision grade standard for hybrid ceramic ball bearings
The overall size and rotational accuracy level of the bearing shall be in accordance with GB/ISO standards, with precision ranging from low to high: P0 → P6 → P5 → P4 → P2 (ultra precision highest level)
• P0: General machinery, normal speed
• P6/P5: General high-speed motors, ordinary precision equipment
• P4 level: CNC machine tool spindle, high-speed electric spindle, servo motor high-precision standard configuration
• Level P2: Ultra precision grinding machines, semiconductor equipment, aerospace ultra high precision core components
Single precision grade of ceramic balls (GB/T 308.2) Classification of roundness of ceramic balls: G5>G10, the smaller the number, the higher the precision
• G5 level: ultra precision spindle, servo, semiconductor, diameter tolerance ≤± 0.002mm, ultimate roundness
• G10: Conventional high-speed precision motors, new energy electric drives
Core precision indicators of high-precision bearings • Micro scale control of radial runout and end face runout.
• Raceway roughness Ra ≤ 0.02 μ m
• Precise grouping of clearance (C1/C2/C3/C4), suitable for high-speed and low-temperature rise, high-precision rigidity requirements
DN's maximum speed can reach over 3 million, far exceeding 1.5 times the same specification of all steel bearings
Core advantages of high-precision hybrid ceramic ball bearings
1. Ultra high speed operation: Ceramic balls are lightweight, with low centrifugal force and significantly increased maximum speed. The temperature rise is 30%~50% lower than that of steel bearings
2.Ultra high rotational accuracy: Ceramic has high rigidity, low deformation, and low vibration
3.Insulation and electrical corrosion prevention: Ceramics are non-conductive, completely solving the problem of electrical corrosion failure of variable frequency motors and new energy high-voltage shaft currents
4.Ultra long service life: less friction, lower wear, and fatigue resistance, with a service life of 3-10 times that of steel bearings under the same working conditions
5.Corrosion resistant, non-magnetic, high temperature resistant, clean without metal precipitation, suitable for extreme special environments
6.Low noise, low vibration, extremely stable long-term high-speed operation
Application of high-precision hybrid ceramic ball bearings in the industry
1. CNC machine tool&machining center spindle, high-speed electric spindle, grinder spindle, machining center spindle, P4/P2 high-precision silicon nitride ceramic bearings, ultra-high speed, high-precision cutting, low temperature rise, long-term stable high-precision machining.
2.Servo motors, precision high-speed motors, full range of servo motors, stepper motors, high-speed variable frequency motors, insulation anti axis current, low inertia high response, high-precision positioning, long life maintenance free, high-end servo standard
3.New energy vehicle high-voltage electric drive system 800V high-voltage platform drive motor, Block high-voltage shaft current, prevent bearing corrosion damage, high temperature resistance, high speed, lightweight, and extend the service life of the electric drive system.
4.Semiconductor and microelectronic precision equipment wafer processing, lithography equipment, precision testing instruments, non-magnetic, insulated, clean and dust-free, ultra-high rotation accuracy, Not interfering with precision electrical control and sensing signals.
5. Medical precision equipment, dental high-speed mobile phones, medical centrifuges, surgical precision transmission equipment, stainless steel rings+ceramic balls, sterile and corrosion-resistant, no metal pollution, ultra-high stability and low noise.
6. Aerospace, precision instrumentation, aviation servos, high-speed components of model aircraft, precision measuring instruments, lightweight, high reliability, high and low temperature stability, long-term service under extreme working conditions.
7.Vacuum pumps, pharmaceutical and food machinery are corrosion-resistant, clean, rust free, oil-free, self-lubricating, and suitable for clean working conditions. They operate stably in acidic and alkaline environments for a long time.
8. Wind power, railway traction motor generators, and traction motors are insulated to resist stray currents, with long-term maintenance free operation and high reliability in harsh outdoor environments.
As one of the most professional manufacturers of high-precision ceramic ball bearings in China, TKW has provided OEM services for multiple internationally renowned brands. At the same time, we also offer qualified products and professional services to end customers. Our main products include high-precision ceramic ball bearings, servo motor bearings, vacuum pump bearings, ultra-thin wall bearings, cross roller bearings, angular contact bearings, high-speed fan bearings, 440C stainless steel bearings, PEEK bearings, magnetic levitation bearings, electrically insulated bearings, etc.
