Influence of Radial Load on Non Repetitive Run-Out of the Single Ball Bearing

Abstract

A ball bearing is grouped under radial bearing and it rotates with supporting radial load. When a radial force is loaded to a ball bearing, the spring constant of the rotating ball bearing will change periodically assuming that the force is static and fixed, because the stiffness of the bearing depends on the positions of rolling elements. Thus, it can be expected that the radial vibration increases. However, there are few reports on the rotational accuracy in case that a radial force is loaded to a ball bearing. Therefore, in this research, a measuring device for rotational accuracy was developed and the influence of radial load to a ball bearing was analyzed experimentally. Axial and radial forces can be loaded at the same time in the developed measuring device. Consequently, it was verified that the increment of vibration got fewer for smaller variation in radial stiffness of the ball bearing although the radial vibration increased with radial load. In addition, this phenomenon corresponded with the tendency proposed in a previous report by the authors for the number of rolling elements to get high rotational accuracy.