Experimental Method for Determining Ball Bearing Lubricant Quantity Factor

摘要

Ball bearing temperature prediction methods for spacecraft applications require, in part, a knowledge of thelubricant contribution to bearing drag torque. This can be estimated using a model derived by Palmgrenand Snare. When implemented in bearing analysis software, the viscous drag torque model depends on avariable known as the Lubricant Quantity Factor (LQF). This value is critical to understanding spacecraftball bearing temperatures for cases where motion is involved. In this paper, we describe the results ofexperiments that were conducted on a bearing test fixture that is capable of measuring bearing thermalparameters including heat generation of an operating bearing. The heat generation and speedmeasurements are used to determine bearing drag torque, which is then used to determine LQF. We showthat the LQF depends on operating conditions, and that this variability should be considered whencalculating bearing drag and operational temperature.