20090001837 | Hollow Motor Drive Device - A hollow motor drive device includes a screw shaft provided with a spiral screw groove formed in an outer peripheral surface thereof, a nut member screw-engaged with the screw groove, a hollow drive shaft having an inner peripheral side on which the nut member is fixed and an outer peripheral side on which a permanent magnet is disposed, and a housing provided with a bearing portion rotatably supporting the hollow drive shaft and a coil portion. In the hollow drive shaft, the nut member and the permanent magnet are disposed so as not to be overlapped with each other in a direction perpendicular to the axial direction of the hollow drive shaft, and in the housing, the bearing portion is disposed to a position corresponding to the nut member, and the coil portion is disposed to a position corresponding to the permanent magnet. | 01-01-2009 |