Abstract: The problem for designing plane cam mechanism with oscillating follower to have minimal size in accordance with allowable pressure angle was not solved satisfactorily to date. On the basis of the envelop theory of differential geometry, the author derives the equations of the contour line restrictng minimal size in the cam mechanism cited above, from which allowable region of the axis of the cam or its minimal radius of, basis circle and the length of oscillating follower can be showed or calculated respectively on the digital computer this method has applied to the cam mechanism held In contact dy a spring or a positive-drive groove and conjugate cam mechanism. A numerical example is presented at the end of this paper.

Key words: Abrasion, Creep force, Curve-passing, Wheel-rail contact