Kinematic Analysis Of Plannar Cam Mechanism Based Assur-group Method And The Development Of Computer Aided Reverse Design System

According to the current developing situation of cam manufacturing in our country, the importance of inverse-design in the development of cam mechanism is introduced in this paper. It is an important process to design motion law of cam follower in reverse according to measured data of actual cam profile. This paper presents an Assur-group method for the kinematic analysis of plannar cam mechanisms. During inversion, each instantaneous cam mechanism is transformed into an Assur-group in this method. So we can complete the kinematic analysis of the cam mechanism by the analysis of the corresponding Assur- group. Based on the method, this paper deals with plannar disc-cam mechanisms with different types of followers. The main points of this paper are as follows.1. Curve fitting of the actual cam profile with the Cubic-periodic spline function according to the measured data of the cam.2. Analyzing the displacement of the follower based on the Assur-group method and the differentiation of the cubic spline function3. Analyzing the velocity and acceleration of the follower based on the Assur-group method and the inversion of the mechanism.4. Developing a CAD system with Object-Oriented programming, which can perform the kinematic analysis of plannar cam mechanism.Some examples are given in this dissertation. First, the coordinate values of a group of discrete points on the cam profile are achieved by conventional design method which are then used as measured data of the cam profile. Then the kinematic analysis of the cam mechanism is performed by the method developed in this paper. The reverse results are compared to the theoretic values. The reliability and effectiveness of this method are illustrated by the comparison.