SPINDLE CLAMPING DEVICE IN MACHINE TOOL

摘要

A device for clamping coaxial, first and second spindles of a machine tool to each other. The first spindle is hollow and rotatably supported by a spindle head. The second spindle is rotatably supported in the first spindle and can be moved back and forth in the axial direction of the second spindle. The device includes a space formed between portions of both the spindles; disc springs are provided in the space to exert an axial force; and a pair of clamp rings are disposed on both sides of the springs, for clamping both the spindles to each other due to a wedge action through the force of the disc springs. An oil chamber is formed at one side of the pair of clamp rings in order to release the clamping of both the spindles when oil pressure is applied. A hydraulic pressure source is provided for supplying pressurized oil into the oil chamber through a static pressure pocket provided at the place where the first spindle is in sliding contact with a bush encircling the first spindle.