Ball Bearing Vibrations : 1st Report, On the Radial Vibration Caused by Passing Balls

Abstract

Vibrations caused by a ball bearing are complicated because a ball bearing has many moving elements. In this first report, the authors deal with the radial vibration of a shaft caused by balls passing the bottom of the shaft, the frequency of which is given by the product of the retainer speed (in rpm) and the number of balls. The authors calcutated the statical radial displacement of a shaft caused by the passing balls in the bearing, and carried out its measurement which actually showed the existence of the displacement of this sort. From the analytical and experimental results, it was found that if the outer race was distorted in an oval form, the amplitude of the displacement due to the passing balls becomes generally larger. Furthermore, the authors investigated the shaft vibration caused by the passing balls. Experimental results concerning amplitudes and phase differences of the vibrations of the shaft and its pedestal, agreed with the analytical results.