Process cartridge and electrophotographic image forming apparatus

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein the main assembly includes a motor, a driving rotatable member for receiving a driving force from the motor, and a projection portion provided substantially at a center of the driving rotatable member, the projection portion having a polygonal cross section, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• a process unit arranged to act on said photosensitive drum;
• and
• a recess, formed at a longitudinal end of said photosensitive drum, said recess having a polygonal cross section,
• wherein, when the rotatable member rotates with said recess and the projection portion engaged with each other, a rotational driving force is transmitted from the rotatable member to said photosensitive drum through said recess and the projection potion, with said recess being pulled into the projection portion, and
• wherein a free end of the projection portion and a bottom surface of said recess contact each other so that said photosensitive drum is positioned in place along a longitudinal direction relative to the maim assembly.

An electrophotographic image forming apparatus for forming an image on a recording material, said apparatus adapted to receive a detachably mountable process cartridge, said apparatus comprising:

• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a projection portion provided substantially at a center of said driving rotatable member, said projection portion having a polygonal cross section;
• a detachable mounting member for detachably mounting the process cartridge, the process cartridge including:
• an electrophotographic photosensitive drum;
• a process unit arranged to act on the photosensitive drum;
• and
• a recess formed at a longitudinal end of the photosensitive drum, the recess having a polygonal cross section,
• wherein, when said driving rotatable member rotates with the recess and said projection portion engaged with each other, a rotational driving force is transmitted from said driving rotatable member to the photosensitive drum through the recess and said projection portion, with the recess being pulled into said projection portion, and
• wherein a free end of said projection portion and a bottom surface of the recess contact each other so that the photosensitive drum is positioned in place along a longitudinal direction relative to a main assembly;
• and
• a feeding unit arranged to feed the recording material.