Patent ID: 7059996

Claim:
A planetary gear drive, comprising: an internal gear, a sun gear disposed concentrically within the internal gear, at least one planetary gear in meshed engagement with the internal gear and sun gear, a carrier that rotatably supports the planetary gear, a housing that houses the above gears and carrier, and an input-side tapered roller bearing and an output-side tapered roller bearing attached to an inner peripheral surface of the housing, said tapered roller bearings being positioned along a drive axis at each end of the internal gear, wherein the carrier has an output-side disc-shaped end plate portion and a cylindrical portion extending to an input side of the drive from the output-side disc-shaped end plate portion, the disc-shaped end plate portion of the carrier is rotatably supported on an inner peripheral surface of the housing by means of the output-side tapered roller bearing, an input-side portion of the cylindrical portion of the carrier is rotatably supported on the inner peripheral surface of the housing by means of the input-side tapered roller bearing, and the sun gear is inserted concentrically into the cylindrical portion from the input side, wherein the internal gear is a thin, elastically resilient internal gear capable of radial elastic deformation, and wherein the sun gear is incorporated in a floating state that enables it to move perpendicularly to the axis.