INFLUENCE OF WORKING CONDITIONS ON THE TEMPERATURE REGIME OF THE BEARINGS WITH METAL AND CERAMIC BALLS

Abstract

The results of an experimental study of the temperature mode of operation of rolling bearings under different lubrication conditions are presented. Comparative tests of all-metal bearings and similar bearings with rolling elements made of silicon nitride (hybrid bearings) when lubricated with an oil jet and an oil-air mixture in the range of rotor rotation frequencies from 0 to 35000 rpm were carried out. For the experiments, a specially created set was used, which allows you to study the temperature of the bearings and the temperature of the lubricant at the entrance and exit from the bearings. The axial load on the bearings was created with the help of a compression spring, which rested on the outer rings of the bearings. This made it possible to close the load inside the system. During the tests, the load was 0 N, 1000 N, and 2000 N. Tests were carried out for two modes of bearing lubrication: oil jet and oil-air mixture. The method of measuring the temperature of the outer ring of bearings is described. The temperature measurement error was considered as a complex of instrumental error and method error. It was assumed that the temperature error is subject to a normal distribution. The conducted analysis showed that the error of measuring the temperature of the bearing ring was ± 2.8 °C with a confidence probability of 95 %. It has been established that bearings with ceramic balls in the entire studied range behave qualitatively and quantitatively in approximately the same way as with steel ones. The temperature level of hybrid bearings is slightly higher when lubricated with both an oil jet and an oil-air mixture. There is a clear connection between the values of the bearing temperature and the moment of resistance in the bearing: the increase in temperature is observed under the same conditions under which the moment of resistance increases.