Reduction gear drive utilising flexible toothed wheel - provides large reduction ratio with compactness and low weight and positive drive

摘要

The drive housing (7) embodies a fixed gear ring (1) with internal teeth. Within this ring is a flexible gear ring (3) in the form of a sleeved thin-walled tube whose length is greater than the thickness of the fixed gear ring. The input shaft (6) is coupled via reduction gears (45, 46) to a hollow shaft (14) carrying three eccentrics (26, 27, 28) with ball bearing mounted rings (38, 39, 40). The rings of the eccentrics press against the sleeve of the flexible gear ring, forming it to an oval shape so that its teeth engage with those of the fixed ring in two regions. Since the flexible ring has fewer teeth than the fixed ring, the former rotates at a speed proportional to the difference. Couplings (8, 9) transmit the rotation to the output flange.