Recirculating ball screw drive - with staggered return paths cut in nut wall to improve load distribution

摘要

The channels for the balls (31) in the nut (15) are semicircular in cross section as they are in the shaft matching the diameter of the balls. The ends of the channel in any set are connected together by recessing the groove further into the nut, so that the balls can recirculate over the lands between the shaft grooves. This portion of the channel is angled in the opposite direction to that of the normal part of the thread, relative to the shaft axis. The recirculating channels of each set are staggered in angular position around the shaft, this improving bad distribution.