Low friction load nut on lifting spindle - is self locking in case of power failure

摘要

A load carrying nut (2) on a vertical load lifting spindle (1) has a number of equally spaced screw rollers (8) which are in mesh with the thread of the spindle (1). To reduce friction between nut and spindle, the screw rollers are located on pivot pins (3) by means of roller bearings (4). Axial thrust bearings (7) transmit the load from the nut body (2) to the screw rollers (8). A one way clutch (6) between the pivot pin (3) and the screw roller (8) prevents the rollers from rotating about the pivots when the load is lowered. This ensures that normal friction between nut and spindle occurs so that in case of a power failure, the nut would be self jamming.