Brief introduction of high-speed rolling bearing The so-called high-speed bearing does not have an absolute limit. It is generally considered that dn ≥ mm r/min is considered to be 僦岢; some bearings, although dn < mm r/min, their rotational speed reaches or exceeds 1.6 times the limit speed listed in the sample is also often regarded as a high-speed bearing. In practical applications, the dn value of the bearing has reached 2.2×mm·r/min. In addition to pitting damage, the failure modes of high-speed bearings include raceway burns, cage breakage, cage guide edge wear, lubricating oil failure, and excessive vibration. Therefore, there are many factors that limit the bearing speed. Bearings running at high speed need to have high accuracy of the bearing itself. The raceway of the bearing should have very accurate geometric shape, minimum eccentricity and low surface roughness value, and the rolling elements should also have high sorting accuracy. . When the bearing is running at high speed, the rolling elements will press on the outer ring raceway under the action of a large centrifugal force, and the relative sliding between the rolling element and the inner ring raceway will occur due to the reduction of pressure, resulting in excessive wear and even burns. Proper preload on the shaft o helps prevent slippage between the rolling elements and the rings. Strengthening the lubrication and cooling of high-speed bearings as much as possible is another important measure to ensure the reliable operation of high-speed bearings. The vibration and noise of high-speed bearings has become an important subject of research in recent years. In order to reduce or eliminate the impact of bearing vibration on the vibration of the whole machine, in addition to improving the conditions of the bearing itself, measures can also be taken in support design.

Introduction to high temperature rolling bearings It is generally believed that bearings with a working temperature higher than 120 ℃ can be called high temperature bearings. The main failure modes of high temperature bearings are: overheating burns, annealing or surface fatigue pitting. When selecting, the requirements for bearing materials and heat treatment process should be put forward, appropriate lubricants and lubrication methods should be selected, and attention should be paid to the influence of temperature on bearing fit and oil gap. Ordinary mineral lubricating oil is a petroleum product, which will be oxidized into fatty acid at high temperature, which will cause the bearing to corrode and fail. If used properly, the oil supply method is good, and there is experience with mineral oil at 280 °C. However, it is generally believed that the working temperature of petroleum lubricating oil should be lower than its flash point to ensure safety. When the temperature is higher, solid lubricants can be used. In addition, in the structural design of high-temperature bearings, we should focus on strengthening cooling and heat dissipation, and try to reduce the working temperature of the bearing.

Introduction to ceramic bearings The ceramic material used in bearings is mainly silicon oxide, which has the characteristics of high hardness, high temperature resistance and light weight. The advantages of this bearing are: good high-speed rotation performance, high wear resistance, good dimensional stability at high temperature, etc. Silicon oxide bearings have been used in aircraft, machine tool spindles and other machinery, and are currently in the development stage.