Modeling Concave Globoidal Cam with Swinging Roller Follower : A Case Study

This paper describes a computer-aided design for design of the concave globoidal cam with cylindrical rollers and swinging follower. Four models with different modeling methods are made from the same input data. The input data are angular input and output displacements of the cam and the follower and some other geometrical parameters of the globoidal cam mechanism. The best cam model is the cam which has no interference with the rollers when their motions are simulated in assembly conditions. The angular output displacement of the follower for the best cam is also compared with that of in the input data to check errors. In this study, Pro/ENGINEER® Wildfire 2.0 is used for modeling the cam, simulating motions and checking interference and errors of the system.

Authors:

• Nguyen Van Tuong
• Premysl Pokorny

Keywords:

• Globoidal cam
• sweep
• pitch surface
• modeling.

References:

[1] H. Y. Cheng, "Optimum tolerances synthesis for globoidal cam
mechanism," JSME international Journal, series C, vol. 45, no. 2, 2002,
pp. 519-526.
[2] Y. En-hui, Z. Chun, D. Ji-xian, "Creating surface of globoidal indexing
cam profile on computer," Journal of Northwest University of Light
Industry", vol.19, no.1, 2001, pp. 41-43.
[3] Z. Koloc, M. Vaclavik, "Cam mechanism," Elsevier, 1993.
[4] J. Reeve, "Cam for industry," Mechanical Engineering Publications,
London, 1995.
[5] H. A. Rothbart (editor), "Cam design handbook," McGraw-Hill, 2004.
[6] D. M. Tsay and S. Y. Lin, "Generation of globoidal cam surfaces with
conical roller-followers," ASME 2006 International Design Engineering
Technical Conferences & Computers and Information in Engineering
Conference, Philadelphia, USA, 2006, DETC2006-99683.
[7] H. S. Yan and H. H. Chen, "Geometry design and machining of roller
gear cams with cylindrical rollers," Mech. Machine Theory, vol. 29, no.
6, 1994, pp. 803-812.
[8] H. S. Yan and H. H. Chen, "Geometry design of roller gear cams with
hyperboloid rollers," Mathematical and computing modeling, vol. 22,
no. 8, 1995, pp. 107-117.
[9] http://www.proengineertips.com/part-design/tutorial-create-cam-profilewith-
datum-graph-in-pro-e.html