Calculating conjugate cam profiles by vector equations

Abstract

This paper presents an analytical approach for determining the profiles of conjugate disc cams. For a conjugate cam mechanism, its two normal lines through the points of contact and the line of centres must always intersect at a common point, which is an instant centre. On this basis, the contact points between the conjugate cam and the follower can be determined according to the locations of instant centres and follower position. The cam profiles, the paths of the cutter and the pressure angles can then be expressed in the form of parametric vector equations. For various types of conjugate cams, the equations for such expressions are formulated, and examples are provided to illustrate the approach. The procedure is especially simple to program.

Keywords

conjugate cam profile instant centre vector

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References

Hanson

R. S.

Churchill

F. T.

Theory of envelopes provides new cam design equations. Product Engng, 20 August 1962, 45–55.

Davidson

J. K.

Calculating cam profiles quickly. Mach. Des., 7 December 1978, 151–155.

Paul

Kinematics and Dynamics of Planar Machinery, 1979, pp. 285–289 (Prentice-Hall, Englewood Cliffs, New Jersey).

Martin

G. H.

Kinematics and Dynamics of Machines, 2nd edition, 1982, p. 212 (McGraw-Hill, New York).

Rothbart

H. A.

Cams: Design, Dynamics, and Accuracy, 1956, pp. 78–89 (John Wiley, New York).

Molian

The Design of Cam Mechanisms and Linkages, 1968, pp. 64–70 (American Elsevier, New York).

Jensen

P. W.

Cam Design and Manufacture, 2nd edition, 1987, pp. 94–105 (Marcel Dekker, New York).