Abstract:

ESDU 83008 provides a general method for determining the minimum size of cam and swinging follower configuration to suit a given application. Input information required includes the timing chart, the rotation speed, the cam law and the variation of the torque on the follower through the cycle. Then, for roller followers, by means of a geometric construction that minimises the contact forces, the swinging arm length and cam size are determined. The maximum pressure angle also has to be checked, and the dimensions may have to be changed to keep it within selected limits. The roller radius is determined from contact stress and interference considerations. For flat-faced followers, the minimum cam radius of curvature is fixed by eliminating high contact stresses and undercutting. Comprehensive practical worked examples illustrate the use of the techniques for both roller and flat-faced followers.