Dynamic Characteristics of Non-Uniform Motion Mechanisms with Ball Bushings : 1st Report, On the Friction of Ball Bushings and Dynamic Characteristics of Mechanisms

Abstract

In order to clarify the dynamic characteristics of non-uniform motion mechanisms with ball bushings as prismatic or cylindric pairs, the frictional characteristics of ball bushings have been investigated, and the behavior of a mechanism at low speeds has been analysed in relation to the frictional characteristics. Moreover the vibration caused by inertia forces at high speeds has been investigated.The frictional characteristics have been revealed to deteriorate remarkably under light or eccentric loads. It has been clarified that stick-slip-vibrations occur in mechanisms with ball bushings owing to the difference between the coefficients of static and kinetic frictions.Dynamic behavior of a spatial four-bar mechanism with a ball bushing at low speeds is governed by the frictions of the bushing. An approximate analysis has been made of the vibration caused by inertia forces of links at high speeds.