Abstract:

ESDU 93001 presents a method for calculating values of compressive stress in the contact region between a disc cam and a roller follower at regular intervals during one rotation of the cam. The calculation of contact stress is a vital step in the design of a cam mechanism and is especially useful when selecting a suitable material and heat treatment for the cam surface.

The method involves calculation of force acting at the cam/roller interface due to follower system inertia, externally-applied load and the action of the return spring. Values of contact force, together with values of cam profile radius of curvature, roller dimensions and materials properties of the cam and roller, are used to calculate contact stress. A computer program (ESDUpac A9301) that performs all the necessary calculations is provided with this Data Item. Also provided is a Windows executable interface program (VIEWpac W9301) that allows the program to be run in a user friendly manner. The program includes an option allowing the user to determine suitable values of spring rate and preload to ensure that contact between cam and follower is maintained.

The Item includes a full description of the mathematical model on which the calculation is based together with guidance on the use of the program, including interpretation of the output. Three examples illustrating the use of the program in realistic design situations are presented.