Compact articulated reduction gearing - has balls acting as both bearings and planet gears with preload eliminating whiplash

摘要

The compact articulated drive reduction gearing for output shaft rotation has no play in its moving parts and is consequently very rigid. It provides large reduction ratios of order 100 to 250. The input shaft (37) is supported in a fixed sleeve (36) and drives a bevel gear (16) via a pinion (38). An adjustable keyed sleeve (10) is used to mount the gear on two back-to-back circular ball tracks (9). The tracks are split and one half (7) rotates with the output flange (20) and arm (4), while the other (8) is supported on the fixed sleeve (36). A cross shaft (21) is used to apply a pre-load across the output flanges to take up any backlash. The balls perform both the bearing and also the planet wheel function in the gear train, thus keeping the design compact. They may be substituted by conical pinions. In addition, the input shaft and pinion may be replaced by a self-contained hydraulic motor.