Effect of Bolted Joint Layer on the Vibration Characteristics of Spindle Rotor

Abstract

This paper describes an investigation of the effect of joint layer on the vibration characteristics of a spindle rotor. The test rotor is composed of a journal part and two thrust plates bound with bolts. Each thrust plate and a journal part are clamped with eight M4 bolts which are arranged on the circle at 45 degrees intervals with a uniform clamping torque. The each surface of bolted joints is processed by two methods in order to change the roughness or roundness of surface. In this paper, we consider the lower three bending vibration mode of the spindle. In all conditions of surface of joint layer, natural frequencies increase and damping ratios decrease as the clamping torque of each bolt increases. On the other hands, in all condition of clamping torque, natural frequencies increase and damping ratios decrease as the roughness and roundness of surface decreases. Moreover, we can decrease the resonance amplitude by increasing clamping torque, decreasing roughness and roundness of surface.