Abstract: A new approach, called a relative motion method (RMM), is proposed for designing the shape of the disk cam, which uses the relative velocity, relative acceleration and normal line at the contact between a follower and a cam to discover the profile coordinate, the pressure angle and the radius of curvature on the cam. Their general expressions are derived based on an inverse model with special coordinate systems and homogeneous transformation techniques. It is characterized by the procedures of derivation and solution not only manually but also with computers. According to the designed strategy, a program for design automation of shape of the disk cam and the kinematics simulation of this kind of mechanism is developed using the proposed approach with C++ and OpenGL language. Finally, an example is given.

Key words: CAD, Cam mechanism, Disk cam, Modeling and simulation