Patent ID: 7229380
Filing Date: 2007-06-12
Classification: B21D,F16H

Abstract:
1. A power transmission device comprising a hollow, outer shaft, to one end of which a drive gear is fixed, an inner shaft extending through the drive gear and the outer shaft in the coaxial relationship with the outer shaft and having a carrier fixed to an extension thereof from the drive gear, a planetary gear mechanism comprising a sun gear arranged in the coaxial relationship with the inner shaft, a plurality of planetary gears supported rotatably on the carrier to engage with the sun gear, and a ring gear having internal teeth and external teeth, the internal teeth engaging with the planetary gears, and an input shaft having a first gear that engages with the drive gear, and a second gear that engages with the external teeth of the ring gear, the arrangement being such that the outer shaft and the inner shaft are rotated with the same number of revolutions in the same direction when the sun gear is kept stationary and the input shaft is rotationally driven, and that a position of the inner shaft in a direction of rotation is adjusted relative to the outer shaft when the sun gear is rotated.