Collet chuck provided with a driven movable member which can be driven hydraulically in two opposite directions for operating a collet

摘要

A collet chuck includes a tubular body and a rotating shaft assembly that is journalled within the tubular body and that defines a frustoconical recess therewithin. A belt pulley is sleeved fixedly on the rotating shaft assembly. A collet is disposed operably within the recess in the rotating shaft assembly, and is adapted to hold a rod-shaped workpiece therewithin. A movable member is mounted axially and movably within the tubular body for movement in tightening and loosening directions. A front oil chamber is formed in the tubular body, and is located immediately in front of the movable member. A rear oil chamber is formed in the tubular body, and is located immediately behind the movable member. A first oil passage is formed in the tubular body and is in fluid communication with the front oil chamber so that hydraulic oil can be fed thereinto, thereby moving the movable member within the tubular body in the tightening direction so as to compress the collet. A second oil passage is formed in the tubular body and is in fluid communication with the rear oil chamber so that hydraulic oil can be fed to thereinto, thereby moving the movable member within the tubular body in the loosening direction so as to release the collet.