Ceramic Bearing Introduction
作为一种重要的机械基础件，由于其具有金属轴承所无法比拟的优良性能，抗高温、超强度等在新材料世界一马当先。 As an important mechanical foundation, ceramic bearing has excellent performance unmatched by metal bearings. Its high temperature resistance and super strength have taken the lead in the world of new materials. In the past ten years, it has been used more and more widely in various fields of national economy and people's livelihood. What is a ceramic bearing As the name implies, the materials used in bearings are: engineering ceramics, bearing inner rings, bearing outer rings, and bearing rolling elements are all engineering ceramic materials. The standard cage material is: PTFE / PEEK. Under certain circumstances, cage materials can also be used in engineering. Ceramic material processing. Ceramic bearing material classification Zirconia ceramic bearing The all-ceramic bearing has the characteristics of anti-magnetic electrical insulation, abrasion and corrosion resistance, oil-free self-lubrication, high temperature and high cold resistance, etc. It can be used in extremely harsh environments and special working conditions. Ferrules and rolling elements are made of zirconia (ZrO2) ceramic material, and the holder uses polytetrafluoroethylene (PTFE) as a standard configuration. Generally, glass fiber reinforced nylon 66 (RPA66-25) and special engineering plastics (PEEK, PI), stainless steel (AISISUS316), brass (Cu), etc. 2.Silicon nitride ceramic bearings Silicon nitride all-ceramic bearing rings and rolling elements are made of silicon nitride (Si3N4) ceramic materials. Generally, RPA66-25, PEEK, PI, and phenolic laminated bakelite pipes can also be used. Compared with ZrO2 materials, all ceramic bearings made of SiN4 are suitable for higher speed and load capacity, as well as higher ambient temperature. At the same time, it can provide precision ceramic bearings for high-speed, high-precision and high-rigidity spindles, with the highest manufacturing accuracy of P4 to UP. 3. Alumina ceramic bearings Alumina full ceramic bearing rings and rolling elements are made of silicon nitride (Al2O3) ceramic materials. Generally, RPA66-25, PEEK, PI, and phenolic laminated bakelite pipes can also be used. Compared with ZrO2 materials, all-ceramic bearings made of Al2O3 can be applied to higher ambient temperatures. The maximum temperature of full-ball alumina all-ceramic bearings can reach 1200 ° C. 4. Hybrid ceramic ball bearings Ceramic balls, especially silicon nitride balls, have the characteristics of low density, high hardness, low friction coefficient, anti-magnetic electrical insulation, wear resistance, self-lubrication and good rigidity. They are especially suitable for high-speed, high-precision and long-life hybrid ceramic ball bearings. Rolling elements (inner and outer rings are bearing steel. Generally, inner and outer rings are made of bearing steel (GCr15) or stainless steel (AISI440C, AISI420). Ceramic balls can be made of ZrO2, Si3N4, or SiC.) 5. Silicon carbide ceramic bearings Silicon carbide is an inorganic non-metallic material with high hardness, high wear resistance, low friction coefficient, strong oxidation resistance, good thermal stability, low thermal expansion coefficient, large thermal conductivity, and resistance to thermal shock and chemical corrosion And other excellent characteristics, it can be used in various mechanical and equipment that require wear resistance, corrosion resistance and high temperature resistance. The silicon carbide bearings produced by our company use a new generation of pressure-free sintered silicon carbide (SSIC). Plain green, high-purity, high-density, free silicon-free SIC sintered at high temperature using pressureless sintering process, hardness, strength, corrosion resistance, high temperature resistance, impact resistance and other properties of pressureless sintering All are better than other engineering ceramics such as zirconia, silicon carbide reaction and sintering, etc. The silicon carbide all-ceramic bearing rings and rolling elements are made of non-pressure silicon carbide (SIC) ceramic materials. The cage purchases PTFE as a standard configuration, compared to zirconia bearings. Material, suitable for higher temperature and more severe corrosive environment. Code of ceramic bearing Engineering ceramic bearings with ceramic bearing model suffix plus CE, CE represents ceramic bearings, such as 6204-2RS means bearing steel 6204 with rubber seals, 6204-2RS CE means: ceramic bearings 6204 with rubber seals. Classification of ceramic bearings 1. High-speed bearing: It has the advantages of cold resistance, low stress elasticity, high pressure resistance, poor thermal conductivity, light weight, and low friction coefficient. It can be applied to high-speed spindles of 12,000 to 75,000 rpm and other high precision Equipment 2. High temperature bearing: The material itself has a high temperature resistance of 1200 ° C and good self-lubrication. The use temperature does not cause expansion due to temperature differences between 100 ° C and 800 ° C. Can be used in furnaces, plastics, steel and other high temperature equipment; 3. Corrosion-resistant bearings: The material itself has the characteristics of corrosion resistance, and can be used in the fields of strong acid, alkali, inorganic, organic salt, seawater, etc., such as: electroplating equipment, electronic equipment, chemical machinery, shipbuilding, medical equipment, etc. 4. Anti-magnetic bearing: Because it is non-magnetic, it does not suck dust, which can reduce the surface peeling of the bearing, thereby reducing running noise. Can be used in demagnetization equipment. Precision instruments and other fields. 5. Electrically insulated bearings: Due to the high electrical resistivity, the bearings can be prevented from being damaged by arcs, and can be used in various electrical equipment that requires insulation. 6. Vacuum bearings: Due to the unique oil-free self-lubricating characteristics of ceramic materials, in the ultra-high vacuum environment, it can overcome the problem that ordinary bearings cannot achieve lubrication. Note: For the above five types of bearings, the same set of bearings can be applied to high temperature, high speed, acid and alkali, magnetic field, non-insulation, but due to different material properties (please refer to the performance table of rare earth ceramic materials), when customers choose products, According to your application, choose the most suitable ceramic bearing. Ceramic bearing advantages 1. Since ceramics are scarcely resistant to corrosion, ceramic rolling bearings are suitable for operation in harsh conditions covered with corrosive media. 2. Since the elastic modulus of ceramic is higher than that of steel, it is not easy to deform when subjected to force, so it is conducive to improving the working speed and achieving higher accuracy. 3. Since the density of the ceramic rolling balls is lower than that of steel, and the weight is much lighter, the centrifugal effect of the outer ring can be reduced by 40% when rotating, and the service life is greatly extended. 4. Ceramic is less affected by thermal expansion and contraction than steel, so when the bearing clearance is constant, the bearing can be allowed to work in an environment where the temperature difference changes drastically. Ceramic bearing applications 1. Medical equipment, low temperature engineering, optical instruments, high speed machine tools, high speed motors, printing machinery, food processing machinery. 2.In the fields of aerospace, navigation, nuclear industry, petroleum, chemical industry, light textile industry, machinery, metallurgy, electric power, food, locomotive, subway, high-speed machine tools and scientific research and defense military technology, it needs to be in high temperature, high speed, deep cold, Inflammable, explosive, strong corrosion, vacuum, electrical insulation, non-magnetic, dry friction and other special working conditions, the indispensable role of ceramic bearings is gradually being recognized. 3. With the continuous progress of processing technology and the increasing level of technology, the cost of ceramic bearings has continued to decline. It has been applied in a small range of high, precision and sophisticated areas in the past, and has gradually been extended to various industrial sectors of the national economy. Products The market price is also gradually approaching practicality, reaching a level acceptable to users. The wave of large-scale application of ceramic bearings has surged!