2008 Volume 2 Issue 5 Pages 887-895
Nonrepetitive runout (NRRO) is mainly caused by the diameter differences of balls contained in a bearing and the form errors of the raceway and balls. This paper deals with the effect of grease lubrication on NRRO. The results can be summarized as follows. (1) NRRO in the case of grease lubrication was larger than that in the case of oil lubrication. (2) The rotational frequency of cage increased with the increment of unbalance or rotational speed. In the rotational accuracy on the level of one nanometer, it was clarified that the lubricant was a very important factor in a ball bearing.
