Tapered Roller Bearing Rib-Roller End Interaction at Hydrodynamic Contact

Abstract—

Wear of the contact surfaces is an important characteristic of rib-roller end interaction of roller bearings. The purpose of this study was to develop effective methods for calculating the wear rate of these surfaces under alternating dynamic loads. In wear rate calculations of bearing parts, as a rule, Archard’s law is used since it has been verified in hydrodynamic friction testing of bearing steels. In the paper, based on this law, a direct step-by-step wear rate calculation method for rib-roller end contact at variable loads and sliding speeds is developed. According to it, normal force, sliding velocity, and contact oil film thickness are determined in bearing dynamic modeling, and the finite element method is used to calculate contact pressure fields. A multi-mass bearing dynamic model includes a contact friction model, which allows an adequate description of hydrodynamic contact behavior of solid bodies. Using the bearing life dependence on the oil film parameter and experimentally measured steel bearing wear rates, the dependence of wear coefficient on the oil film parameter is obtained. The direct calculation method involves many computations, which makes the influence of individual factors on wear rate non-obvious. In this regard, a method of wear rate calculation with averaged parameters is also proposed. Using these two methods, rib-roller end wear calculations for a double-row tapered roller bearing are implemented. The spherical shape of the roller end and conical, toroidal convex, and concave shapes of the rib are considered. Comparison of wear rates obtained by the two methods confirms the acceptable accuracy of calculations with averaged parameters. The results in particular demonstrate that a toroidal concave rib surface allows reducing the wear rate up to three times in comparison with the tapered surface.