Patent ID: 8862030
Filing Date: 2014-10-14
Classification: G03G

Abstract:
1. A driving assembly for a photosensitive drum, connected to a drive shaft having a triangular twisted hole to transfer a rotary driving force from an image forming apparatus, the driving assembly comprising: a supporting body combined at one side of the photosensitive drum; and an engaging protrusion twistedly protruding from the supporting body and inserted into the twisted hole, wherein the engaging protrusion having three or more line contact portions on its cross-section perpendicular to the protrusion direction, the line contact portions being in line contact with a twisted surface of the twisted hole, wherein at least one portion of a surface formed by continuously joining the line contact portions along the protrusion direction is a twisted contact surface that is in surface contact with the twisted surface of the twisted hole to receive the rotary driving force transferred by the drive shaft, and wherein the twisted contact surface includes a contact expansion region in which a length of the line contact portion gradually increases as getting closer to a base portion from a front end portion.