Patent ID: 8840512
Filing Date: 2014-09-23
Classification: F16H

Abstract:
1. A backlash-free planetary transmission device, comprising: a housing; a power input shaft and a power output shaft; an eccentric sleeve securely positioned on a circumference of the power input shaft; a dual outer gear including a first outer gear and a second outer gear; an outer ring of the eccentric sleeve that rotatably fits with the dual outer gear; a fixed pin gear on the housing and that is concentric with the power input shaft; and a power output pin gear on the power output shaft in circumferential transmission fit and that is concentric with the power input shaft, wherein the first outer gear of the dual outer gear is meshed with the fixed pin gear with small teeth number difference; the second outer gear of the dual outer gear is meshed with the power output pin gear with small teeth number difference; each of the fixed pin gear and the power output pin gear includes a roller that can rotate around its own axis; an outer surface of the roller is a gear surface; profiles of teeth of the first and second outer gears of the dual outer gear are respectively enveloped by profiles of the fixed pin gear and the power output pin gear meshed therewith; both the fixed pin gear and the power output pin gear are bevel gears formed by tilting the roller; the first and second outer gears of the dual outer gear are bevel gears; and the fixed pin gear tapers in a direction opposite to that of the power output pin gear.