Patent ID: 8886087

Claim:
A photosensitive drum driving head for a process cartridge of an image forming apparatus, engaged with a driving head of the image forming apparatus for power transmission, the driving head of the image forming apparatus comprising a twisted recess and power transmission portions provided with twisted bevels having edges engaged with the photosensitive drum driving head, the photosensitive drum driving head comprising: a drum flange disposed on the end portion of a photosensitive drum and connected with the photosensitive drum; a drum shaft axially extended from the end portion of the drum flange; and a boss axially extended from the end face of the drum shaft and engaged with the twisted recess, wherein at least one convex tooth, radially extended along the boss and engaged with the power transmission portion, formed on the side wall of the boss; and the convex tooth provided with a first side face and a second side face being a graded bevel gradually varied towards the root of the convex tooth along the end portion of the convex tooth; wherein the convex tooth is provided with a mating surface parallel to an axial line of the photosensitive drum, and the mating surface is engaged with the edge of the twisted bevel in the recess of the image forming apparatus to transmit power.