Patent ID: 9268247
Filing Date: 2016-02-23
CPC Classification: F16D,G03G,Y10T

Claim Text:
1. A power transmission device, comprising: a drive coupling to receive power from a drive source of a main body of an image forming apparatus and rotate; a driven coupling disposed coaxially on a first rotary shaft of the drive coupling and detachably attachable relative to the main body of the image forming apparatus; and an intermediate transmission member, including at least a first flange, to mesh with the drive coupling and the driven coupling, the intermediate transmission member being held by one of the drive coupling and the driven coupling in a state in which the driven coupling is disengaged from the main body, wherein one of the drive coupling and the driven coupling, whichever holds the intermediate transmission member, constituting a retaining coupling including an attachment member attached to one of a drive-side device and a driven-side device, and a stopper assembly including at least a second flange facing the first flange of the intermediate transmission member in an axial direction of the first rotary shaft to prevent the intermediate transmission member from falling off from one side of the retaining coupling, wherein the stopper assembly includes an opposed portion formed on the retaining coupling and facing the intermediate transmission member in the axial direction, and a stopper attached to the retaining coupling to interpose a portion of the intermediate transmission member with the opposed portion in the axial direction, wherein the retaining coupling includes a projection extending in a direction of rotation of the retaining coupling, and the stopper includes a notch fitted with the projection to attach the stopper to the retaining coupling, wherein the retaining coupling includes external teeth and the attachment member includes the projection, wherein the intermediate transmission member includes internal teeth to mesh with the external teeth of the retaining coupling and an external-tooth opposed portion facing the external teeth of the retaining coupling in the axial direction, and the external-tooth opposed portion is interposed between the external teeth of the retaining coupling and the stopper to prevent the intermediate transmission member from falling off from the retaining coupling, and wherein at least one of a surface of the external-tooth opposed portion facing the stopper and a surface of the stopper facing the external-tooth opposed portion is curved outwardly.