Hydrostatic bearing device, spindle device for machine tool using hydrostatic bearing device, and manufacturing method of hydrostatic bearing device

摘要

A hydrostatic bearing apparatus includes a bearing metal having a hydrostatic portion that allows a grinding wheel shaft to be rotatably supported. The hydrostatic portion has a bearing clearance, a bearing surface portion, a plurality of pockets, and partition plates. Clearances are each formed between the corresponding partition plate and an edge of the corresponding pocket in a rotating direction of the grinding wheel shaft. The clearances are formed in the pocket at upstream and downstream ends in the rotating direction. The bearing clearance has a first bearing clearance and a second bearing clearance. The second bearing clearance is larger than the first bearing clearance.