SBIR-STTR Award

This proposal will investigate a new method for grinding the outside (OD) and inside diameters (ID) of rolling contact bearing rings at a single clamping of the bearing ring. Currently, two grinding machines are necessary; one for the OD, and one for the ID. This proposal seeks a new method to hold the rings without distorting them while leaving the OD and ID accessible to the grinding wheels and thereby eliminating the machine set-up time, tooling cost, and capital investment in one machine. The research work in this Phase 1 will conduct bench testing of a prototype fixture. This phase will also develop a computer round-up simulation program for the grinding round-up process, incorporating the sources of out-of-roundness. Both of these research objectives should lead to improved bearing accuracy and reduced manufacturing cost. If successful, the basis for developing a ID/OD bearing grinder will be established. Follow-on phases are planned which involve grinding bearing rings held in a prototype fixture and determining the actual capabilities of the ID/OD grinding concept, followed by commercial development of a ID/OD bearing grinder. This research should lead to a new grinder that will produce higher quality bearings at lower cost, which should be of significant benefit to rolling contact bearing manufacturers as well as users of these bearings.

The objective of this research is to provide an improved method of grinding anti-friction bearing outer and inner race rings at lower cost but of higher quality. Current production practice requires an external grinding machine to grind the outside diameter (OD) or raceway, and an internal grinding machine to grind the inside diameter (ID) or internal raceway. This study seeks a method of grinding the OD and ID on one grinding machine, thereby eliminating the tooling cost, setup, maintenance, and capital required for one grinding machine. This method focuses on a device for securely holding and driving the thin-walled rings without distortion while providing access for the OD and ID grinding wheels to grind the OD and the ID of the bearing ring. This project covers a study of the out-of-roundness produced by asymmetrical rigidity in the clamping system. In addition, the propagation of initial stock runout to cause roundness errors in the finished bearing ring when grinding with fast, high-production cycles will be investigated. The work-holding and driving method coupled with force- adaptive control, using force sensors, provides a means for improving grinding performance and reducing production costs in the antifriction bearing industry.