Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit

A process cartridge comprising:

• a casing;
• developer contained within the casing;
• a photosensitive drum having an axis L1, the photosensitive drum being rotatably supported in the casing to permit rotation about the axis L1;
• a developing roller having an axis L1′, the developing roller being configured to develop a latent image formed on the photosensitive drum with the developer, and the developing roller being rotatably supported in the casing to permit rotation about the axis L1′;
• a coupling member operatively connected to the photosensitive drum, the coupling member including a body having an axis L2, and the coupling member including at least one projection provided at an end of the body;
• and
• a post extending in a direction parallel to the axis L1, the post being associated with the coupling member such that a movement of the post relative to the photosensitive drum coincides with a movement of the coupling member relative to the photosensitive drum,
• wherein coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L1 and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L1, with the first distance being greater than the second distance.