Views: 30 Author: Site Editor Publish Time: 2021-10-05 Origin: Site
Within the speed range of 150,000 rpm, a comprehensive comparison and analysis of the change characteristics of the contact angle, contact stress, inner ring displacement, spin-to-roll ratio and stiffness of angular contact ceramic ball bearings and steel ball bearings. According to the analysis of rolling bearings. A mathematical model is established in theory and solved by numerical methods. The analysis results show that: within the research speed range, the above performance parameters show significant non-linear change characteristics, and their change characteristics are closely related to the speed and the type of ball material; in the axial direction Under the action of external load, the inner ring of the bearing moves in the axial direction. As the speed increases, the amount of axial movement first decreases slightly and then increases sharply; the radial stiffness and axial stiffness of the bearing also first decrease and then increase, and the range of change is large. Ceramic ball hybrid bearings are significantly better than traditional steel ball bearings in almost all performance parameters. Compared with traditional steel ball bearings, their contact stress and inner ring movement are significantly reduced, the contact angle changes smaller, and the axial and diameter The degree of change in stiffness is relatively low, and the dynamic characteristics are relatively stable, which has the unparalleled superiority of traditional steel ball bearings.
Compared with stainless steel bearings, ceramic ball bearings can achieve higher speed, greater load capacity and longer service life, and can withstand higher temperatures, better electrical insulation, and stronger corrosion resistance. , Oil-resistant, self-lubricating, if the bearing is completely made of ceramic material, it is better than stainless steel bearings and ordinary bearing steel bearings in many aspects. Ceramic bearings are seeking to achieve higher speed and longer service life, reduce total weight, and high temperature Ideal choice for environment and corrosion resistance, mainly used in cryogenic pumps, medical equipment, semiconductors, machine tool spindles, turbine flow meters, food processing equipment, robots and optics. Ceramic bearings mainly use silicon nitride (Si3N4), zirconia (ZrO2) ), alumina (AI2O3) or silicon carbide (SiC)
Ceramic materials have a very low coefficient of friction, which is ideal for applications seeking to reduce friction. Ceramic balls require less lubricant and have stronger hardness than steel balls, which improves the service life of the bearing, and its thermal performance is better than that of the bearing. Steel balls generate less heat at high speeds. Full ceramic bearings have a cage (PEEK/PTFE) design or a full ceramic ball design.
Hybrid ceramic ball bearings use ceramic balls. The weight of ceramic balls is 40% smaller than steel balls of the same size, which reduces centrifugal load and reduces friction and rolling resistance. Therefore, the speed of hybrid ceramic ball bearings is higher than that of traditional steel ball bearings. At present, hybrid ceramic ball bearings It is the preferred type for high-speed applications.
1. The fatigue life of all-ceramic bearings can be 10-50 times longer than that of all-steel bearings. Hybrid ceramic bearings have a life expectancy of 3-5 times longer than that of all-steel bearings. In terms of service life, ceramic bearings are much higher than steel ball bearings.
2. The friction coefficient of ceramic bearings is low, so oil-lubricated ceramic bearings, when the lubricating oil becomes thin or lacking, its lubricating ability is still not lower than the traditional lubricants commonly used in steel bearings;
3. The rigidity of ceramic bearings is greater than that of metal bearings, the elastic modulus of ceramic materials is higher, and its rigidity is 15-20% greater than that of ordinary steel bearings.
4. Compared with metal bearings, ceramic bearings are more resistant to corrosion and abrasion. Because of the different materials of its own, it directly causes the corrosion resistance and wear resistance of ceramic bearings to be better than that of metal bearings.