Electrophotographic photosensitive drum, process cartridge, and electrophotographic image forming apparatus

摘要

The main assembly of an electrophotographic image forming apparatus includes a motor, a main assembly gear (71) for transmitting a driving force from the motor via a non-circular twisted hole (71a) having a section with a plurality of corner portions provided at a central portion of the main assembly gear, the non-circular twisted hole being rotatable integrally with the main assembly gear. An electrophotographic photosensitive drum of a process cartridge detachably mountable to the main assembly includes a non-circular twisted projection (61b) provided on its one longitudinal end and having a section with a plurality of corner portions (61b1), which are engageable with the twisted hole to receive the driving force when mounted to the main assembly; a recess (65) formed in the central portion of the projection and having a bottom portion (65a) and a side surface portion (65b). When the projection receives a pulling force toward the twisted hole by rotation of the main assembly gear both the bottom portion and the side surface portion is contacted to a spherical surface portion (70a) provided at a central portion of the hole (65a1).