Drehantriebsvorrichtung für Presse

摘要

A rotary driving device for a press machine includes: a main body (11); a push head member (21) provided for the main body (11) reciprocatingly movably in an axial direction thereof and driven in the axial direction by a striker (S) of the press machine; an air-tight gaseous spring unit (15) mounted inside the main body (11), for generating a return elastic force to urge the push head member (21) in a direction opposite to a strike direction of the striker (S); a male thread axle member (29) in mesh with female threads (33) formed in the main body (11) and rotatable when moved in an axial direction thereof by the push head member (21); a lead nut (47) exchangeably and fixedly mounted on the main body (11); a lead thread member (51) in mesh with the lead nut (47) and rotatably supported by the main body (11), for holding a rotary driven tool (T); and a coupling section (43, 55) for coupling the male thread axle member (29) and the lead thread member (51) in torque transmission relationship and in relative axial displacement relationship with respect to each other so as to absorb a difference in axial speed between both the members (29, 51). Since at least one air-tight gaseous spring unit (15) is mounted inside the main body, it is possible to prevent the gas leakage without maintenance and thereby to realize an unmanned press machine without replenishment of the gas for many hours.