Patent ID: 9592582
Date: 2017-03-14
CPC Classifications: B23P,B24B

Claim:
1. A device for grinding a spherical end face of a roller-shaped workpiece, the device comprising: a first rotary retaining member that is provided at a first rotary drive shaft and rotates at a predetermined speed; a second rotary retaining member that is provided at a hollow second rotary drive shaft disposed so as to be concentric with the first rotary drive shaft, and rotates at a predetermined speed; a carrier disposed so as to be rotatable relative to the first rotary retaining member and the second rotary retaining member; and a cup-shaped rotary grinding wheel disposed so as to be (i) movable relative to the first rotary retaining member and the second rotary retaining member and (ii) movable in axial and radial directions of the first rotary drive shaft, wherein: pressure is applied to the first rotary retaining member or the second rotary retaining member in an axial direction, one of the first rotary retaining member and the second rotary retaining member is an inner rotary retaining member that is configured to retain a workpiece at a first point and that has an annular outward rolling surface formed of part of a radially outward tapered surface centering on a central axis of the rotary drive shafts, the other one of the first rotary retaining member and the second rotary retaining member is an outer rotary retaining member that has an annular inward rolling surface formed of part of a radially inward tapered surface centering on the central axis of the rotary drive shafts, and the annular inward rolling surface includes an annular recess at a middle portion thereof so that the outer rotary retaining member is configured to retain the workpiece at second and third points that are separated from each other by the annular recess, the rolling surfaces are opposed to each other, a workpiece supporting portion that is configured to support the workpiece such that the workpiece rotates and revolves as the retaining members rotate is formed at a portion of the carrier, the portion being positioned between the rolling surfaces, and a central axis of the workpiece supportable by the workpiece supporting portion and a central axis of the cup-shaped rotary grinding wheel are each inclined relative to the central axis of the rotary drive shafts at an acute angle.