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

A drum unit comprising:

• a photosensitive drum having an axis;
• a drum flange provided at an end portion of the photosensitive drum, the drum flange being configured to transmit a rotational driving force to the photosensitive drum, the drum flange being rotatable together with the photosensitive drum about the axis of the photosensitive drum, and the drum flange having a hollow interior portion elongated along the axis of the photosensitive drum;
• a coupling member operatively connected to the drum flange, the coupling member being configured to transmit the rotational driving force to the drum flange, the coupling member being rotatable about an axis of the coupling member that is coaxial with the axis of the drum flange, the coupling member including at least one projection for receiving the rotational driving force, the at least one projection being provided at an end portion of the coupling member, the coupling member being movable with respect to the drum flange in a direction of the axis of the photosensitive drum, with the at least one projection being movable with the coupling member in the direction of the axis of the photosensitive drum;
• and
• a spring urging the coupling member in a direction away from the photosensitive drum along the axis of the photosensitive drum,
• wherein at least a part of the spring and at least a part of the coupling member are positioned within the hollow interior portion of the drum flange.

A cartridge comprising:

• a photosensitive drum having a rotational axis about which the photosensitive drum is rotatable;
• a developing roller having a rotational axis about which the developing roller is rotatable;
• a developing frame rotatably supporting the developing roller;
• a drum flange connected to an end of the photosensitive drum, the drum flange including an inner surface facing the rotational axis of the photosensitive drum and a hollow portion inside of the drum flange;
• and
• a casing including a bearing member rotatably supporting the photosensitive drum, the bearing member being positioned at a first end portion of the casing in a direction of the rotational axis of the photosensitive drum, the bearing member including (i) a surface that faces outside of the cartridge and extends perpendicular to the rotational axis of the photosensitive drum, (ii) an opening to the hollow portion of the drum flange, with the rotational axis of the photosensitive drum being positioned within the opening, (iii) a supporting projection rotatably supporting the drum flange by contacting the inner surface of the drum flange, the supporting projection being projected in the direction of the rotational axis of the photosensitive drum toward a second end portion of the casing that is opposite to the first end portion of the casing in the direction of the rotational axis of the photosensitive drum, and (iv) a projected part projecting in a direction away from the second end portion of the casing in the direction of the rotational axis of the photosensitive drum,
• wherein, as seen in the direction of the rotational axis of the photosensitive drum, (i) the projected part extends part way around the rotational axis of the photosensitive drum, (ii) the surface of the bearing member extends part way around the rotational axis of the photosensitive drum, and (iii) the rotational axis of the developing roller, the rotational axis of the photosensitive drum, and a predetermined region of the surface of the bearing member are positioned in this order along a first line,
• wherein a distance between at least a part of the supporting projection and the second end portion of the casing in the direction of the rotational axis of the photosensitive drum is shorter than a distance between at least a part of the predetermined region of the surface of the bearing member and the second end portion of the casing in the direction of the rotational axis of the photosensitive drum,
• wherein a distance between at least a part of the projected part and the second end portion of the casing in the direction of the rotational axis of the photosensitive drum is longer than the distance between at least a part of the predetermined region of the surface of the bearing member and the second end portion of the casing in the direction of the rotational axis of the photosensitive drum,
• wherein a distance from the rotational axis of the photosensitive drum to at least a part of the projected part as measured along a second line that is perpendicular to the rotational axis of the photosensitive drum is shorter than a radius of the photosensitive drum that extends from the rotational axis of the photosensitive drum to an outer surface of the photosensitive drum,
• wherein a distance from the rotational axis of the photosensitive drum to at least a part of the surface of the bearing member as measured along a third line that is perpendicular to the rotational axis of the photosensitive drum and is different than the second line is shorter than the radius of the photosensitive drum, and
• wherein the predetermined region of the surface of the bearing member is adjacent to an open space that extends to the rotational axis of the photosensitive drum in a direction perpendicular to the rotational axis of the photosensitive drum.