Patent ID: 7209682
Filing Date: 2007-04-24
Classification: F16D,G03G

Abstract:
1. An electrophotographic photosensitive drum for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus for forming an image on a recording material, the main assembly including a motor, a main assembly gear for transmitting a driving force from the motor, and a non-circular twisted hole 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, said electrophotographic photosensitive drum comprising: (a) a cylinder having a photosensitive layer on a peripheral surface thereof; and (b) a non-circular twisted projection provided on one longitudinal end of said cylinder and having a section with a plurality of corner portions, said non-circular twisted projection being engageable with the hole of the main assembly of the apparatus to receive a rotational driving force for rotating said electrophotographic photosensitive drum from the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus, wherein a recess is formed in a central portion of said projection and has a bottom portion and a side surface portion, wherein in a state that said projection receives a pulling force toward the hole by rotation of the main assembly gear with said projection and the hole being engaged with each other, said bottom portion contacts a spherical surface portion provided at a central portion of the hole, and said side surface portion contacts the spherical surface portion, and wherein when the process cartridge is mounted to the main assembly of the apparatus, and said electrophotographic photosensitive drum receives the rotational driving force for rotating said electrophotographic photosensitive drum from the main assembly of the apparatus, an end of the spherical surface portion contacts said bottom portion, and the spherical surface portion contacts said side surface portion in a state that said projection receives the pulling force and that a gap is provided between a free end of said projection and a bottom portion of the hole.