Analysis of Ball Bearings with 2, 3 or 4 Contact Points

Abstract

An analysis of an arched ball bearing that considers centrifugal forces and gyroscopic effects is performed. Based on operating conditions of a 5 DOF inner ring and Coulomb friction model, the conventional bearing theory is extended from 2 to 3 and 4 contacts. The commonly used control criterion of a ball bearing by the inner or outer raceway is debatable and is known to fit experimental data with difficulty, and when more than two contact points are involved it becomes obsolete. The paper presents a mathematical model to describe the ball internal kinematics under the effect of the operating conditions. This analysis makes it clear that the total power loss varies strongly with the one or two added sources of friction. The maximum PV factor is also affected by the full sliding of the lightly loaded contacts induced by the arched design.

KEY WORDS:

• Rolling Element Bearing
• Arched Ball Bearing
• Internal Kinematics
• Centrifugal Forces
• Gyroscopic Effects

ACKNOWLEDGMENTS

The authors would like to thank Snecma for their financial support and encouragement. The views expressed within this article are those of the authors and not necessarily those of Snecma. The authors would also like to thank Florence Bon and Daniel Plona of Snecma for helpful discussions and encouragement. One of the reviewers is also gratefully acknowledged for his helpful suggestions.

Proceedings of STL 2007 62nd Annual Meeting & Exhibition MAy 6-10, 2007,Φladelphia, USA

Review led by Bob Bruce