EFFECT OF RADIAL INTERNAL CLEARANCE OF A BALL BEARING ON THE DYNAMICS OF A BALANCED HORIZONTAL ROTOR

The response of a balanced horizontal rigid motor rotor supported by a deep groove ball bearing is theoretically simulated. The effect of radial internal clearance of the ball bearing on the dynamic response of the rotor is studied. The system equations have been numerically integrated, the results of which have been validated with harmonic balance alternating frequency time domain method. Variation of radial internal clearance shifts the peak response as the speed is changed over a range. The results of a parametric study done by taking radial internal clearance have resulted in the observation of a third region of instability which has not been reported in literature. The appearance of regions of periodic, subharmonic and chaotic behavior is seen to be strongly dependent on the radial internal clearance. The system response is analyzed for stability and nature with the help of Floquets method for stability analysis and generation of higher order Poincare maps. The bearing stiffness is estimated experimentally and the effect of variation in radial internal clearance on the bearing stiffness is studied.