Dynamic characteristics of spindle-bearing with tilted pedestal and clearance fit

Abstract

Spindle-bearing systems are widely used in machine tools, aero engines, and other industrial equipment. The vibration characteristics of the spindle system may be affected by the pedestal tilt due to assembly errors. Considering the radial and axial clearance fit between the bearing outer ring and the pedestal, the six-degree-of-freedom (6-DOF) frictional contact relationship between the outer ring and the pedestal is described, and a novel clearance fit model is proposed. In addition, the quasi-static models of deep groove ball bearings (DGBBs), angular contact ball bearings (ACBBs), and cylindrical roller bearings (CRBs) are established with the effects of rotational speed. The clearance fit model, quasi-static models of the bearings, and finite element (FE) model of the spindle are coupled to develop a dynamic model of a spindle-bearing system with pedestal tilt error. The contact performances of the DGBB and the vibration behaviors of the system with pedestal tilt errors are analyzed by simulation and experiment. The results show that the amplitude of the time-domain acceleration response decreases first and then increases with the increase of the pedestal tilt degree. The pedestal tilt error increases the contact angle of the DGBB, so the varying compliance (VC) vibration frequency value and its error also increase.