End member which allows transmission of rotary power

An end member to be arranged at an end of a columnar rotor mounted in an image forming apparatus body, the end member including:

• a tubular bearing member;
• and
• a shaft member that is held by the bearing member, wherein the shaft member includes:
• a shaft which moves in an axial line direction,
• a rotary power reception member which is arranged at one end of the shaft and includes an engagement member engaging with a drive shaft of the image forming apparatus body without inclination respect to rotational axis, and
• a regulation member which as one with the bearing member and is positioned to engage with or be separated from the shaft or the rotary power reception member,
• wherein a position of the regulation member with respect to the shaft or the rotary power reception member is adjustable along the axial line direction such that the engagement member switches between an engagement posture and a non-engagement posture with respect to the drive shaft.