Effects of Manufacture and Assembly Errors on the Output Error of Globoidal Cam Mechanisms

The output error of the globoidal cam mechanism can be considered as a relevant indicator of mechanism performance, because it determines kinematic and dynamical behavior of mechanical transmission. Based on the differential geometry and the rigid body transformations, the mathematical model of surface geometry of the globoidal cam is established. Then we present the analytical expression of the output error (including the transmission error and the displacement error along the output axis) by considering different manufacture and assembly errors. The effects of the center distance error, the perpendicular error between input and output axes and the rotational angle error of the globoidal cam on the output error are systematically analyzed. A globoidal cam mechanism which is widely used in automatic tool changer of CNC machines is applied for illustration. Our results show that the perpendicular error and the rotational angle error have little effects on the transmission error but have great effects on the displacement error along the output axis. This study plays an important role in the design, manufacture and assembly of the globoidal cam mechanism.

Authors:

• Shuting Ji
• Yueming Zhang
• Jing Zhao

Keywords:

• Globoidal cam mechanism
• manufacture error
• transmission error
• automatic tool changer.

References:

[1] H. S. Yan, and H. H. Chen, “Geometry design of globoidal cams with
generalized meshing turret-rollers,” Trans. ASME J. Mech. Des., vol. 118,
pp. 243–249, 1996.
[2] J. Astoul, E. Mermoz, M. Sartor, J. M. Linares, and A. Bernard, “New
methodology to reduce the transmission error of the spiral bevel gears,”
CIRP Annals – Manufacturing Technology, vol. 63, pp. 165–168, 2014.
[3] J. J. Coy, R. F. Handschuh, D. G. Lewicki, R. G. Huff, E. A. Krejsa, and A.
M. Karchmer, "Identification and proposed control of helicopter
transmission noise at the sourse", NASA/Army Rotorcraft Technology
Conference, California, 1987, pp. 17–19.
[4] S. T. Ji, J. Zhao, and Y. M. Zhang, "An application of geodesics to the
calculation of the rib-thickness of the globoidal cam mechanisms," Mech.
Mach. Theory, vol. 87, pp. 163-176, 2015.
[5] D. M. Tsay, and B. J. Lin, "Improving the geometry design of cylindrical
cams using nonparametric rational B-splines," Comput. Aided Des., vol.
28, pp. 5-15, 1996
[6] H. S. Yan, and H. H. Chen, "Geometry design and machining of roller
gear cams with cylindrical rollers," Mech. Mach. Theory, vol. 29, pp.
803-812, 1994.
[7] H. S. Yan, "Curvature analysis of roller-follower cam mechanisms," Math.
Comput. Model, vol. 29, pp.69-87, 1999.
[8] D. M. Tsay, and B. J. Lin, "Design and machining of globoidal index
cams," Trans. ASME J. Manuf. Sci. Eng., vol. 119, pp. 21-29, 1997.
[9] J. H. Kuang, C. M. Hsu, and C. C. Hu, "Dynamic behavior of globoidal
cam systems with torque compensation mechanisms," Mech. Mach.
Theory, vol. 45, pp. 1201-1214, 2010.
[10] H. Y. Cheng, "Optimum tolerances synthesis for globoidal cam
mechanisms," JSME, vol. 45, pp. 519-526, 2002.
[11] D. M. Tsay, and H. C. Ho, "Consideration of manufacturing parameters in
the design of grooved globoidal cam indexing mechanisms," Proc.
IMechE C J. Mech. Eng. Sci., vol. 215, pp. 95-103, 2001.
[12] F. H. Bu, Y. M. Zhang, and D. G. Shang, "Study on machining error of
globoidal cam profile resulting from motion error of machine tool in
machining," Applied Mechanics and Materials, vol. 148-149, pp.
1356-1364, 2012.
[13] F. H. Bu, Y. M. Zhang, and D. G. Shang, "Study on machining error of
globoidal cam profile resulting from rotational deviation of location of
part in machining," Advanced Materials Research, vol. 452-453, pp.
211-218, 2012.