Geometrical arrangement of ID grinding wheel in simultaneous-ID/OD combination centreless grinding

Abstract

A new centreless grinding technique to grind simultaneously the inner diameter (ID) and outer diameter (OD) of ring-type workpieces such as inner and outer bearing races is proposed. This has been proposed in order to reduce process cost and improve machining accuracy. In this new method, the OD of a workpiece can be precisely ground under optimum grinding conditions for conventional centreless grinding proposed in previous works. However, it is not clear how to determine the geometrical arrangement of an ID grinding wheel for improving the ID roundness and the concentricity of the ID in relation to the OD. This paper develops a simulation method to investigate the rounding process of the ID and OD of a workpiece under various geometrical arrangements, especially regarding the setup angle of ID grinding wheel. A simulation analysis of the effect of the ID grinding wheel's setup angle on machining accuracy are carried out. Then grinding experiments are performed in order to confirm the simulation results. It is found that the ID grinding wheel should be set up at such a location that the ID grinding point is close to the regulating wheel support point in order to improve ID roundness. The ID grounding point should also be close to the blade support point in order to improve concentricity.