Patent ID: 8292056

Claim:
A roller assembly comprising: a rotary member including a driving shaft portion and a convey roller portion provided with the driving shaft portion, said rotary member being rotatable around an axis of the driving shaft portion; a driving wheel including a hole portion and attached to the driving shaft portion, said driving wheel being driven to rotate; a transmission receiving portion provided with the driving shaft portion, extending radially outward from the driving shaft portion, and rotating together with the driving shaft portion; a frictional transmission member clamped between said transmission receiving portion and a side surface of said driving wheel to frictionally transmit a rotational force of said driving wheel to said rotary member; and biasing means for applying a clamping force between said transmission receiving portion and the side surface of said driving wheel, wherein said driving shaft portion includes a first shaft portion on which said convey roller portion is mounted, a second shaft portion including a diameter smaller than that of said first shaft portion, and an inner hole axially extending through said driving shaft portion and concentric with said driving shaft portion, wherein said transmission receiving portion is disposed at a stepped portion formed between said first shaft portion and said second shaft portion, wherein said driving wheel is disposed on said second shaft portion, and wherein said biasing means comprises: a shaft member inserted into the inner hole; a pushing member disposed on an outer surface of said shaft member on the side of said second shaft portion to push said driving wheel toward said transmission receiving portion; and an elastic member disposed in the inner hole to apply a pushing force for pushing said driving wheel toward said transmission receiving portion to said pushing member through said shaft member.