Patent ID: 6878090
Filing Date: 2005-04-12
Classification: F16H

Abstract:
1. A method for reducing a rotation speed of a drive source to a rotation speed necessary for an object to be driven to thereby transfer an output torque of the drive source, said method comprising the step of providing a planetary differential gear type reduction device comprising: an output gear affixed to an output shaft connected to the object, the output shaft extending through a hole in the output gear wherein the output gear is affixed to an outer surface of the output shaft; a stationary gear smaller in a number of teeth than the output gear and coaxial with the output shaft, but not rotatable; and a planetary gear rotatably mounted on a planetary gear shaft, which is driven by the torque of the drive source to revolve round the output gear and the stationary gear, and revolving round the output gear and the stationary gear in mesh with the output gear and the stationary gear; wherein the planetary gear has a first portion and a second portion meshing with the stationary gear and the output gear, respectively, and having a same number of teeth as each other, and at least one of the output gear, the stationary gear and the first portion and the second portion of the planetary gear comprises a profile shifted gear.