Characteristics of ceramic bearings
Ceramic bearings are high-performance bearings made of ceramic materials (such as silicon nitride, silicon carbide, aluminum oxide, etc.) to manufacture rolling elements (balls, rollers) or rings. They have advantages that traditional metal bearings cannot match. The core characteristics are as follows:
1. Excellent physical properties
High hardness and wear resistance: The hardness of ceramics can reach HRC70 or above (far exceeding the HRC60 of bearing steel), and the wear resistance is improved by 3-5 times, which is suitable for high-load and highly corrosive environments.
Low density and lightweight: The density is only 1/3-1/2 of that of bearing steel (such as silicon nitride density 3.2 g/cm³, bearing steel 7.8 g/cm³), which can significantly reduce rotational inertia and improve high-speed performance.
High temperature resistance: The heat resistance temperature of silicon nitride ceramics reaches 1200℃, and silicon carbide can reach 1600℃, far exceeding the 200-300℃ limit of bearing steel, and is suitable for high-temperature working conditions.
2. Excellent chemical stability
Corrosion and oxidation resistance: Ceramic materials are not easy to react with media such as acids, alkalis, and salts, and their lifespan is more than 10 times longer than that of metal bearings in humid and corrosive environments (such as the ocean and chemical industry).
Non-magnetic and insulating: Ceramics are non-metallic materials that can avoid electromagnetic interference and are suitable for scenes such as precision electronic equipment and medical imaging equipment.
3. Outstanding tribological performance
Low friction coefficient: The surface roughness of ceramics is low, and the friction coefficient is only 0.001-0.002 (about 0.002-0.005 for metal bearings), which can reduce energy consumption and reduce heat generation.
Self-lubricating property: Some ceramic materials (such as silicon carbide) can still maintain certain lubricating properties under non-lubricating conditions, which are suitable for extreme environments.
4. Long life and high reliability
Fatigue resistance: Ceramic materials have fewer internal defects, and their fatigue resistance is more than 50% higher than that of bearing steel, especially when rotating at high speeds, it is not easy for metal fatigue to peel off.
Low expansion coefficient: The thermal expansion coefficient is only 1/3-1/5 of that of metal, which can reduce the dimensional error caused by temperature changes and maintain precision stability.
Emerging application fields of ceramic bearings
Ceramic bearings are gradually replacing traditional metal bearings with their unique performance, showing broad prospects in the following emerging fields:
1. New energy and energy-saving technology
Wind power equipment: used for spindle bearings and gearbox bearings, resistant to high salt spray corrosion environment at sea, with a lifespan 2-3 times longer than that of metal bearings, reducing maintenance costs.
Electric vehicles:
Motor bearings: meet the needs of high-speed rotation (above 20,000 rpm) and lightweight, reduce energy consumption and increase cruising range.
Battery cooling system: resistant to electrolyte corrosion, ensuring long-term stable operation of the system.
Nuclear energy field: used for nuclear reactor cooling pump bearings, resistant to high temperature, radiation and strong corrosion environment.
2. High-end manufacturing and precision instruments
Semiconductor equipment:
Photolithography machine bearings: non-magnetic, low particulate emission characteristics, meeting nano-level precision requirements.
Wafer transfer device: corrosion-resistant, dust-resistant, avoid contamination of semiconductor components.
Aerospace:
Aerospace engine bearings: maintain strength at high temperatures (such as turbine parts), replace traditional alloy bearings, and improve thrust-to-weight ratio.
Satellite attitude control mechanism: self-operating without lubrication in a vacuum environment, with extremely high reliability requirements.
Precision machine tools: used for high-speed spindle bearings (such as above 50,000rpm), reduce heat generation and improve processing accuracy.