Drum unit, drive transmission unit, cartridge and electrophotographic image forming apparatus

A drum unit for a cartridge, the drum unit comprising:

• a photosensitive drum;
• a flange positioned at an end of the photosensitive drum, the flange being coaxial with the photosensitive drum, and the flange being configured to transmit a driving force to the photosensitive drum;
• a first coupling supported by the flange such that at least a part of the first coupling is exposed from the flange to receive the driving force, the first coupling being inclinable relative to the flange;
• a second coupling operatively connected to the first coupling and the flange, the second coupling being configured to transmit the driving force from the first coupling to the flange,
• wherein the first coupling is rotatable part way about a rotational axis of the first coupling and relative to the second coupling by receiving the driving force,
• wherein, the first coupling and the second coupling are configured to move away from each other in a direction of the rotational axis of the first coupling in response to rotation of the first coupling relative to the second coupling, and
• wherein the flange is configured to reduce inclination of the first coupling relative to the flange in response to rotation of the first coupling relative to the second coupling.

A cartridge comprising:

• a photosensitive drum;
• a support member operatively connected to the photosensitive drum;
• a first coupling supported by the support member such that at least a part of the first coupling is exposed from the support member to receive the driving force, the first coupling being inclinable relative to the support member;
• a second coupling operatively connected to the first coupling and the support member, the second coupling being configured to transmit the driving force from the first coupling to the support member,
• wherein the first coupling is rotatable part way about a rotational axis of the first coupling and relative to the second coupling by receiving the driving force,
• wherein, the first coupling and the second coupling are configured to move away from each other in a direction of the rotational axis of the first coupling in response to rotation of the first coupling relative to the second coupling, and
• wherein the support member is configured to reduce inclination of the first coupling relative to the support member in response to the rotation of the first coupling relative to the second coupling.