スピン角度制御型ボール研磨 (第2報): 窒化けい素球の研磨

Ceramic balls are expected to become useful for tougher bearings than conventional ones. However, the conventional ball lapping method which uses a couple of flat and V-groove lapping plates, needs so long machining time. In present paper, efficient lapping method of silicon nitride balls has been proposed. In this method, it is designed that V-groove lapping plate is separated into two parts and three plates are able to rotate independently. This lapping equipment enables the spin angle θ of ball to control from 0° to 90° It is found from the experiments that the spin angle θ of ball has great influence to lapping of silicon nitride one. Stock removal rate increases gradually with increase of the spin angle θ and surface roughness decreases considerably with increase of it in which lapping mode varies from the satin finished surface to scratched one. Experiments indicate that degree of the reduction of deviated diameter of ball from ideal one is dependent both upon the rotational speed and the spin angle