Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
A cartridge includes a photosensitive drum rotatable about an axis thereof and a drum flange provided at one end portion of the photosensitive drum. The cartridge also includes a coupling member operatively connected to the drum flange, with the coupling member being configured to transmit a driving force to the drum flange. The coupling member includes at least one projection for receiving the driving force, with the at least one projection being movable with the coupling member in the direction of the axis of the photosensitive drum. A spring is provided to urge the coupling member along the axis of the photosensitive drum. At least a part of the spring and at least a part of the coupling member are positioned within a hollow interior portion of the drum flange.
1 . A cartridge comprising:
a casing;
developer contained within the casing;
a photosensitive drum rotatable about an axis thereof;
a drum flange provided at one end portion of the photosensitive drum, the drum flange being configured to transmit a 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 including 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 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 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 an interior of the casing 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.
2 . The cartridge of claim 1 , wherein the drum flange is provided with a gear portion on an outer surface of the drum flange.
3 . The cartridge of claim 1 , wherein the drum flange has an opening at one end and is closed at another end, and the opening leads to the hollow interior portion, and
wherein the coupling member extends into the hollow interior portion with the at least one projection positioned outside of the hollow interior portion.
4 . The cartridge of claim 3 , wherein an end portion of the spring contacts an interior surface of the closed end of the drum flange.
5 . The cartridge of claim 4 , wherein the spring is compressed between the coupling member and the closed end of the drum flange.
6 . The cartridge of claim 1 , wherein the drum flange includes an engaging portion positioned within the photosensitive drum and engaging with the photosensitive drum.
7 . The cartridge of claim 6 , further comprising a developing roller,
wherein the drum flange is operatively connected to the developing roller.
8 . The cartridge of claim 1 , wherein the end portion of the coupling member includes a recessed surface, and the at least one projection projects from a surface adjacent to the recessed surface.
9 . The cartridge of claim 1 , wherein the end portion of the coupling member includes an inclined surface, and a maximum distance from the axis of the coupling member to the inclined surface along a line perpendicular to the axis of the coupling member decreases as a distance along the axis of the coupling member from the photosensitive drum increases.
10 . The cartridge of claim 1 , wherein the at least one projection projects to outside of the drum flange and beyond the drum flange in the direction of the axis of the photosensitive drum.
11 . The cartridge of claim 1 , wherein the spring is a coil spring.
12 . 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.
13 . The drum unit of claim 12 , wherein the drum flange is provided with a gear portion on an outer surface of the drum flange.
14 . The drum unit of claim 12 , wherein the drum flange has an opening at one end and is closed at another end, and the opening leads to the hollow interior portion, and
wherein the coupling member extends into the hollow interior portion with the at least one projection positioned outside of the hollow interior portion.
15 . The drum unit of claim 14 , wherein an end portion of the spring contacts an interior surface of the closed end of the drum flange.
16 . The drum unit of claim 12 , wherein the drum flange includes an engaging portion positioned within the photosensitive drum and engaging with the photosensitive drum.
17 . The drum unit of claim 12 , wherein the end portion of the coupling member includes a recessed surface, and the at least one projection projects from a surface adjacent to the recessed surface.
18 . The drum unit of claim 12 , wherein the end portion of the coupling member includes an inclined surface, and a maximum distance from the axis of the coupling member to the inclined surface along a line perpendicular to the axis of the coupling member decreases as a distance along the axis of the coupling member from the photosensitive drum increases.
19 . The drum unit of claim 12 , wherein the at least one projection projects to outside of the drum flange and beyond the drum flange in the direction of the axis of the photosensitive drum.
20 . The drum unit of claim 12 , wherein the spring is a coil spring.
21 . 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.
22 . A cartridge according to claim 21 , wherein, as viewed along the rotational axis of the photosensitive drum, the projected part is arc-shaped.
23 . A cartridge according to claim 21 , further comprising a rotatable shaft that extends in the direction of the rotational axis of the photosensitive drum and is operatively connected to the drum flange, the rotatable shaft being rotatable together with the drum flange, and at least a part of the rotatable shaft being positioned in the hollow portion of the drum flange.
24 . A cartridge according to claim 23 , wherein the space inside of the hollow portion is formed between the inner surface and the rotatable shaft in the direction perpendicular to the rotational axis of the photosensitive drum.
25 . A cartridge according to claim 21 , wherein at least a part of the projected part extends in a direction that is perpendicular to the surface of the bearing member.
26 . A cartridge according to claim 21 , further comprising a coupling member rotatable about an axis of the coupling member, the coupling member being operatively connected to the photosensitive drum by the drum flange such that a rotational force can be transmitted from the coupling member to the photosensitive drum.
27 . A cartridge according to claim 26 , wherein the coupling member is movable between a first position where the axis of the coupling member is coaxial with the rotational axis of the photosensitive drum and a second position where the axis of the coupling member is inclined relative to the axis of the photosensitive drum.
28 . A cartridge according to claim 21 , wherein the open space extends parallel to the first line.
29 . A cartridge according to claim 21 , wherein, as seen in the direction of the rotational axis of the photosensitive drum, at least a part of the projected part, the rotational axis of the photosensitive drum, and at least a part of the surface of the bearing member are positioned in this order along a fourth line that is perpendicular to the first line.
30 . A cartridge according to claim 29 , wherein the open space extends in a direction perpendicular to the rotational axis of the photosensitive drum and parallel to the fourth line.
31 . A cartridge according to claim 21 , wherein the supporting projection includes an outer surface facing away from the rotational axis of the photosensitive drum and contacting the inner surface of the drum flange.
32 . A cartridge according to claim 31 , wherein the supporting projection is annular-shaped around the opening of the bearing member.