Patent ID: 8336210

Claim:
A method of manufacturing spacers for a spindle device, in which device a main shaft of a machine tool is supported relative to a spindle housing by a rolling bearing unit of a radial type capable of supporting an axial load; inner and outer ring spacers are provided in proximate to the rolling bearing units; load bearing portions are provided in the inner and outer ring spacers, respectively, in a fashion confronting with each other in an axial direction with a gap intervening therebetween; the gap intervening between the load bearing portions is of a size sufficient to allow the load bearing portion on the side of the inner ring spacer and the load bearing portion on the side of the outer ring spacer to be brought into contact with each other in a condition, in which the inner and outer rings of the rolling bearing unit are displaced in position a predetermined quantity in the axial direction by the effect of a load brought about as a result of the axial load acting on the main shaft; each of the inner and outer ring spacers is divided into two divided spacer segments along a surface of division extending in a direction perpendicular to the axial direction and passing through the load bearing portions; the inner ring divided spacer segment of the inner ring spacer, having the load bearing portion, and the outer ring divided spacer segment of the outer ring spacer, having the load bearing portion, have equal axially measured widths and the inner ring divided spacer segment of the inner ring spacer, having no load bearing portion, and the outer ring divided spacer segment of the outer ring spacer, having no load bearing portion, have equal axially measured widths; and the axially measured widths of the latter are longer than the axially measured widths of the former by a quantity corresponding to the gap, which method comprises: machining the inner ring divided spacer segment of the inner ring spacer, having the load bearing portion, and the outer ring divided spacer segment of the outer ring spacer, having the load bearing portion, simultaneously, so as to allow them to have the same axially measured width, and, along therewith, machining the inner ring divided spacer segment of the inner ring spacer, having no load bearing portion, and the outer ring divided spacer segment of the outer ring spacer, having no load bearing portion, simultaneously, so as to allow them to have the same axially measured width, to thereby render the latter axially measured widths to be larger than the former axially measured widths by a quantity corresponding to the gap.