Cartridge, mounting method for coupling member, and disassembling method for coupling member

A cartridge comprising:

• a rotatable member rotatable about an axis thereof;
• a coupling member for receiving a rotational force for rotating the rotatable member;
• a cylindrical member movably supporting one end portion of the coupling member inside of the cylindrical member;
• a cylindrical member side force receiving portion, provided inside of the cylindrical member, for receiving the rotational force received by the coupling member;
• a side cover provided at one longitudinal end portion of the rotatable member and covering the cylindrical member so as to permit rotation of the cylindrical member;
• a first regulating portion, provided inside of the cylindrical member, for preventing the one end portion of the coupling member from disengaging in an axial direction of the cylindrical member, wherein the first regulating portion is capable of deformation to allow the one end portion of the coupling member to disengage in the axial direction of the cylindrical member;
• and
• a second regulating portion for regulating the deformation of the first regulating portion in a state in which the one end portion of the coupling member is mounted to the inside of the cylindrical member,
• wherein the side cover includes the second regulating portion.