Bias load analysis and asymmetric modification of rollers in the main drive bearing of large roadheader

An asymmetric modification method for the roller profile was proposed to address the bias load effect of rollers in the main drive bearing of a large roadheader. A contact mechanics model of the bearing was solved, and line contact theory was used to explore the effect of combined load and convexity on the bias load effect. The contact stress was found to be asymmetrically distributed along the contact line. This trend tended to be remarkable with the decrease in axial load or the increase in overturning moment. Symmetrically modified rollers can be used to improve the bias load effect by increasing convexity. However, this process led to the contact stress concentrating in the roller center. The influence of the design parameters for asymmetric modification on the roller profile and the contact stress was considered. The ideal design parameters were determined by using a genetic algorithm. The contact condition and fatigue life were remarkably increased.