The rotation stability of the tapered rollers in a novel ring-type lapping process

Abstract

This work introduces a novel ring-type lapping method for precision machining of tapered rollers. In contrast to the conventional centerless grinding, this method allows for the simultaneous machining of a group of tapered rollers. The stable rotation of the tapered rollers during the lapping process is a prerequisite for achieving a high manufacturing accuracy. Therefore, an investigation is conducted to examine the criteria for achieving a stable rotation of the tapered rollers. First, the equilibrium equation for the tapered rollers in the lapping process was established. The stable rotation region for the tapered rollers was determined according to the stable rotation criteria. The impacts of the included angle of straight groove and the contact force of lapping sleeve on the stable rotation region were examined. The results demonstrated that the tapered roller's stable rotation can only be realized when a specific parameter combination was satisfied. Subsequently, to expand the stable rotation region, the electromagnetic driving force was introduced to enhance the lapping process. An electromagnetic lapping sleeve structure was designed according to the critical electromagnetic force required for the tapered roller's lapping process. Furthermore, the structure of the electromagnetic lapping sleeve was optimized by electromagnetic simulation in order to improve the uniformity of the electromagnetic driving force exerted on each tapered roller. Finally, the rotation movement of the tapered rollers and the critical electromagnetic forces exerted on the tapered rollers were validated on a ring-type tapered roller lapping platform. The results demonstrated that the stable rotation of the bearing rollers in the lapping process can be achieved throughout a wide range of processing parameters. The roundness of the tapered rollers was significantly improved from 0.83 μm to 0.47 μm on the stable rotation condition. This study established a solid foundation for the precision machining of tapered rollers.