INDEXING DEVICE FOR MACHINE TOOLS

摘要

A pressure receiving member (34b) formed in a hollow circular cylindrical shape is disposed in the space between a ring-shaped clamp sleeve (34a) and a frame (31b), and the clamp sleeve (34a) is disposed so as to be fitted to a shaft part (38b) formed integrally with a rotating shaft (39). At an outer peripheral part (34a2) of the clamp sleeve (34a), there is formed a thin-wall part (34a5) created by a ring groove (34al) that is continuously formed over the entire circumference of the clamp sleeve (34a), within the axial area of the outer peripheral part fitted to the inner peripheral part (34b3) of the pressure receiving member (34b). A pressure chamber (34d) communicating with a fluid control circuit is formed in the space surrounded by both the ring groove (34a5) and the pressure receiving member (34b). A predetermined gap (34d2) is formed between an inner peripheral surface (31b4) of a through hole (31b1) in the frame and the outer peripheral surface (34b) of the pressure receiving member (34b2).