GB961389A - Grinding machine - Google Patents

Abstract

961,389. Grinding machines. HEALD MACHINE CO. Oct. 29, 1962 [Nov. 2, 1961], No. 40764/62. Heading B3D. A grinding machine for finishing a workpiece having an external surface of revolution, including support means contacting the external surface, means for rotating the workpiece about the axis of the surface, a wheelhead comprising an abrasive wheel mounted on a spindle, and means for effecting abrading action by relative movement between the wheel and workpiece, is provided with shoes 45, 46, Fig. 2, associated with a support 38, the shoes being formed of elastomer material of high resistance to abrasion. Material suitable for the shoes is defined as a solid polyurethane comprising a polyester and a diisocyanate. The invention is described as applied to a machine for the machining of the internal surfaces of ball-bearing rings having provision for maintaining a constant grinding pressure and for compensating for the deflection of the wheel spindle when under heavy pressure. The wheel head 14 is axially movable on slideways 18, 19 carried by a plate 21 supported by a base 15 which also carries a plate 31 on slideways 28, 29, this plate supporting the workhead 13 having a magnetic or other face-plate 32 on which the work 12 is secured. The plate 21 is pivoted at 25 on the base 15, an actuator 27 providing pressure by hydraulic means between the work 12 and the grinding wheel 17. A second actuator 47 opposes and balances the grinding pressure through the plate 31 on which the work-head is mounted. A further actuator 26 reciprocates the wheel 17 within the bore during grinding. A regulator R in the hydraulic system maintains the grinding pressure at a predetermined level under which the spindle of the wheel 17 deflects by a known amount, the inclination of the plate 21 through the actuator 27 being such that the wheel axis remains parallel with the axis of the workpiece.