Numerical Analysis on Lubricating Properties of Tripod Sliding Universal Joints

Abstract

The tripod sliding universal joint is a new-style universal joint advanced recently and can be widely used in all kinds of machines, especially automobiles. However, lubricating insufficiency inducing severe and frequent failures shortens its working life and then further limits its popularization and utilization. In this article, in light of the redesigned slide rod with several annular bumps around a column, the geometrical model of the local mating surfaces is established. A numerical solution is obtained under the Newtonian flow model and isothermal conditions using the resulting geometrical model. The effects of effective radius, frequency, and amplitude (1/2 of a stroke) on the variations of pressure and film thickness during a working cycle are discussed. The overall film thickness increases with an increasing effective radius but the overall pressure distribution is just the reverse. The higher the frequency, the thicker the overall film thickness is. The effect of frequency on the pressure distribution mainly focuses on the neighborhood of the second peak. The effect of amplitude on pressure and film thickness shows many discrepancies compared with that of frequency.

KEY WORDS:

• Elastohydrodynamic Lubrication (EHL)
• Tripod Sliding Universal Joint
• Film Thickness
• Reciprocating Motion
• Pressure Distribution

ACKNOWLEDGEMENTS

The work described in this article was supported by the National Natural Science Foundation of China (Grant No. 50475007). The authors acknowledge the support of Prof. P. Yang and Prof. F. Guo, which was helpful in successfully accomplishing the study described in this article.

Review led by Gary Barber