Process cartridge, electrophotographic image forming apparatus, driving force transmission part, and electrophotographic photosensitive drum

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a driving rotatable member for receiving a driving force from said motor, and a twisted hole having a polygonal cross-section and formed substantially coaxial with said driving rotatable member, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted polygonal prism projection provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said hole and projection engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a twisted hole substantially coaxial with said driving rotatable member, said hole having a polygonal cross-section;
• means for mounting a process cartridge, the process cartridge including:
• an electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted polygonal prism projection provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said hole and projection engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole;
• moving means for imparting relative movement between said hole and said projection in a longitudinal direction of said photosensitive drum;
• and
• means for feeding the recording material.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a driving rotatable member for receiving driving force from said motor and a twisted hole substantially coaxial with said driving rotatable member, said hole having a substantially triangular cross-section, said process cartridge comprising:

• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• and
• a twisted substantially triangular prism projection provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said hole and projection engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole;
• and wherein said projection is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame.

An electrophotographic image forming apparatus, for forming an image on a recording material, having a main assembly to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a twisted hole formed substantially coaxial with said driving rotatable member, said hole having a substantially triangular cross-section;
• means for mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• and
• a twisted substantially triangular prism projection provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said hole and projection engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole,
• wherein said projection is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame;
• moving means for imparting relative movement between said hole and said projection in a longitudinal direction of said photosensitive drum;
• and
• means for feeding the recording material.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a main assembly side helical gear for receiving driving force from said motor and a twisted hole substantially coaxial with said main assembly side helical gear, said hole having a substantially triangular cross-section, said process cartridge comprising:

• a cartridge frame;
• an electrophotographic photosensitive drum;
• a charging roller for charging said photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• a cleaning blade for removing residual toner from said photosensitive drum;
• and
• a twisted substantially triangular prism projection provided at a longitudinal end of said photosensitive drum, wherein when said main assembly side helical gear rotates with said hole and projection engaged with each other, rotational driving force is transmitted from said main assembly side helical gear to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole;
• and wherein said projection is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame, and wherein said projection, drum helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said substantially triangular prism projection, satisfy:
• D1>F.gtoreq.C.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a main assembly side helical gear for receiving driving force from said motor;
• a twisted hole substantially coaxial with said main assembly side helical gear, said hole having a substantially triangular cross-section, said hole being formed in an end of a circular column projected from a substantially central portion of said main assembly side helical gear;
• means for mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum;
• a charging roller for charging said photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• a cleaning blade for removing residual toner from said photosensitive drum;
• and
• a twisted substantially triangular prism projection provided at a longitudinal end of said photosensitive drum, wherein when said main assembly side helical gear rotates with said hole and projection engaged with each other, rotational driving force is transmitted from said main assembly side helical gear to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole;
• and wherein said projection is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame, and wherein said projection, drum helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said substantially triangular prism projection, satisfy D1>F.gtoreq.C;
• an openable cover for permitting mounting and demounting of said process cartridge relative to said main assembly;
• moving means for moving said hole away from said projection in interrelation with opening of said cover, and for moving said hole toward said projection in interrelation with closing of said cover;
• and
• means for feeding the recording material,
• wherein a dedendum diameter G of said drum helical gear and an inner diameter D2 of said photosensitive drum, satisfy:
• G>D2, and G>F.gtoreq.C.

A drive transmission part for transmitting a driving force to an electrophotographic photosensitive drum and a developing roller for developing a latent image formed on said photosensitive drum, which are contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving a driving force from said motor, and a twisted hole substantially coaxial with said driving rotatable member, said hole having a polygonal cross-section, said drive transmission part comprising:

• a transmission part gear for transmitting a driving force from said main assembly to said developing roller when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said transmission part gear;
• and
• a twisted polygonal prism projection provided at an end of said shaft, wherein said projection receives a driving force from the main assembly through engagement between said hole and projection, wherein the driving force is transmitted to said photosensitive drum through said shaft, and is transmitted to said developing roller through said transmission part gear.

A drive transmission part for transmitting driving force to an electrophotographic photosensitive drum and a developing roller for developing a latent image formed on said photosensitive drum, which are contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a main assembly side gear for receiving driving force from said motor, and a twisted hole substantially coaxial with said main assembly side gear, said hole having a substantially triangular cross-section, said drive transmission part comprising:

• a helical gear for transmitting driving force from said main assembly to said developing roller when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said helical gear;
• and
• a twisted substantially triangular prism projection provided at an end of said shaft, wherein when said main assembly side gear rotates with said hole and projection engaged with each other, rotational driving force is transmitted from said main assembly side gear to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole, and the driving force is transmitted to said photosensitive drum through said shaft and is transmitted to said developing roller through said helical gear,
• wherein said projection, helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said projection, satisfy:
• D1>F.gtoreq.C.

A photosensitive drum, which is contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving a driving force from said motor, and a twisted hole substantially coaxial with said driving rotatable member, said hole having a polygonal cross-section, said photosensitive drum comprising:

• a cylinder having a photosensitive layer thereon;
• and
• a drive transmission member mounted to an end of said cylinder, said drive transmission member including:
• a drum gear for transmitting a driving force from said main assembly to a developing roller provided in the process cartridge when the process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said drum gear;
• and
• a twisted polygonal prism projection provided at an end of said shaft, wherein said projection receives a driving force from the main assembly through engagement between said hole and projection, wherein the driving force is transmitted to said photosensitive drum through the shaft, and is transmitted to said developing roller through said drum gear.

A photosensitive drum, which is contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a main assembly side gear for receiving driving force from said motor, and a twisted hole substantially coaxial with said main assembly side gear, said hole having a substantially triangular cross-section, said photosensitive drum comprising:

• a cylinder having a photosensitive layer thereon;
• and
• a drive transmission member mounted to an end of said cylinder, said transmission member including:
• a helical gear for transmitting driving force from said main assembly to a developing roller provided in said process cartridge when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said helical gear;
• and
• a twisted substantially triangular prism projection provided at an end of said shaft, wherein when said main assembly side gear rotates with said hole and projection engaged with each other, rotational driving force is transmitted from said main assembly side gear to said photosensitive drum through engagement between said hole and said projection with said projection being pulled into said hole, and the driving force is transmitted to said photosensitive drum through said shaft and is transmitted to said developing roller through said helical gear,
• wherein said projection, helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said projection, satisfy:
• D1>F.gtoreq.C, and
• wherein a spur gear is provided, at another end of said cylinder, for transmitting the driving force for rotating an image transfer roller in the main assembly when said process cartridge is mounted to the main assembly.

An electrophotographic image forming apparatus for forming an image on a recording material, said apparatus comprising:

• an electrophotographic photosensitive drum;
• charging means for charging said photosensitive drum;
• developing means for developing a latent image formed on said photosensitive drum into a toner image;
• transfer means for transferring the toner image onto the recording material;
• fixing means for fixing the toner image on the recording material;
• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a twisted prism projection substantially coaxial with said driving rotatable member, said projection having a polygonal cross-section;
• a twisted polygonal hole having a polygonal cross-section and provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said projection and hole engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection;
• and
• moving means for imparting relative movement between said projection and said hole in a longitudinal direction of said photosensitive drum.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a driving rotatable member for receiving a driving force from said motor and a twisted prism projection substantially coaxial with said driving rotatable member, said projection having a polygonal cross-section, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted polygonal hole having a polygonal cross-section and provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said projection and hole engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a twisted projection substantially coaxial with said driving rotatable member, said projection having a polygonal cross-section;
• means for mounting a process cartridge, the process cartridge including:
• an electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted polygonal hole provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said projection and hole engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection;
• moving means for imparting relative movement between said projection and said hole in a longitudinal direction of said photosensitive drum;
• and
• means for feeding the recording material.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a driving rotatable member for receiving a driving force from said motor and a twisted projection substantially coaxial with said driving rotatable member, said projection having a substantially triangular cross-section, said process cartridge comprising:

• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• and
• a twisted substantially triangular hole provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said projection and hole engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection;
• and wherein said hole is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a driving rotatable member for receiving a driving force from said motor;
• a twisted projection substantially coaxial with said driving rotatable member, said projection having a substantially triangular cross-section;
• means for mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• and
• a twisted substantially triangular hole provided at a longitudinal end of said photosensitive drum, wherein when said driving rotatable member rotates with said projection and hole engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection,
• wherein said hole is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame;
• moving means for imparting relative movement between said projection and said hole in a longitudinal direction of said photosensitive drum;
• and
• means for feeding the recording material.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a main assembly side helical gear for receiving driving force from said motor and a twisted projection substantially coaxial with said main assembly side helical gear, said projection having a substantially triangular cross-section, said process cartridge comprising:

• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• a cleaning blade for removing residual toner from said photosensitive drum;
• and
• a twisted substantially triangular hole provided at a longitudinal end of said photosensitive drum, wherein when said main assembly side helical gear rotates with said projection and hole engaged with each other, rotational driving force is transmitted from said main assembly side helical gear to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection;
• and wherein said hole is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame, and wherein said hole, drum helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said hole, satisfy:
• D1>F.gtoreq.C.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge is detachably mountable, said apparatus comprising:

• a motor;
• a main assembly side helical gear for receiving driving force from said motor;
• a twisted projection substantially coaxial with said main assembly side helical gear, said projection having a substantially triangular cross-section, and said projection being formed in an end of a circular column projected from a substantially central portion of said main assembly side helical gear;
• means for mounting a process cartridge, the process cartridge including:
• a cartridge frame;
• an electrophotographic photosensitive drum;
• a developing roller for developing a latent image formed on said photosensitive drum;
• a cleaning blade for removing residual toner from said photosensitive drum;
• and
• a twisted substantially triangular hole provided at a longitudinal end of said photosensitive drum, wherein when said main assembly side helical gear rotates with said projection and hole engaged with each other, rotational driving force is transmitted from said main assembly side helical gear to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection;
• and wherein said hole is provided at an end of a shaft substantially coaxial with a drum helical gear for transmitting rotational force to said developing roller, and wherein said shaft functions to rotatably support said photosensitive drum in said cartridge frame, and wherein said hole, drum helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said projection, satisfy D1>F.gtoreq.C;
• an openable cover for permitting mounting and demounting of said process cartridge relative to a main assembly of said image forming apparatus;
• moving means for moving said projection away from said hole in interrelation with opening of said cover, and for moving said projection toward said hole in interrelation with closing of said cover;
• and
• means for feeding the recording material,
• wherein a dedendum diameter G of the drum helical gear and an inner diameter D2 of said photosensitive drum, satisfy:
• G>D2, and G>F.gtoreq.C.

A drive transmission part for transmitting a driving force to an electrophotographic photosensitive drum and a developing roller for developing a latent image formed on said photosensitive drum, which are contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving a driving force from said motor, and a twisted projection substantially coaxial with said driving rotatable member, said projection having a polygonal cross-section, said drive transmission part comprising:

• a gear for transmitting a driving force from said main assembly to said developing roller when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said gear;
• and
• a twisted polygonal hole provided at an end of said shaft, wherein said hole receives a driving force from the main assembly through engagement between said projection and hole, wherein the driving force is transmitted to said photosensitive drum through the shaft, and is transmitted to said developing roller through said gear.

A drive transmission part for transmitting driving force to an electrophotographic photosensitive drum and a developing roller for developing a latent image formed on said photosensitive drum, which are contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a main assembly side gear for receiving driving force from said motor, and a twisted projection substantially coaxial with said main assembly side gear, said projection having a substantially triangular cross-section, said drive transmission part comprising:

• a helical gear for transmitting driving force from said main assembly to said developing roller when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said helical gear;
• and
• a twisted substantially triangular hole provided at an end of said shaft, wherein when said main assembly side gear rotates with said projection and hole engaged with each other, rotational driving force is transmitted from said main assembly side gear to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection, and the driving force is transmitted to said photosensitive drum through said shaft and is transmitted to said developing roller through said helical gear,
• wherein said hole, helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said projection, satisfy:
• D1>F.gtoreq.C.

A photosensitive drum, which is contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving a driving force from said motor, and a twisted projection substantially coaxial with said driving rotatable member, said projection having a polygonal cross-section, said photosensitive drum comprising:

• a cylinder having a photosensitive layer thereon;
• and
• a drive transmission member mounted to an end of said cylinder, said transmission member including:
• a gear for transmitting a driving force from said main assembly to a developing roller when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said gear;
• and
• a twisted polygonal hole provided at an end of said shaft, wherein said hole receives driving force from the main assembly through engagement between said projection and hole, wherein the driving force is transmitted to said photosensitive drum through the shaft, and is transmitted to said developing roller through said gear.

A photosensitive drum, which is contained in a process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a main assembly side gear for receiving driving force from said motor, and a twisted projection substantially coaxial with said main assembly side gear, said projection having a polygonal cross-section, said photosensitive drum comprising:

• a cylinder having a photosensitive layer thereon;
• and
• a drive transmission member mounted to an end of said cylinder, said transmission member including:
• a helical gear for transmitting driving force from said main assembly to a developing roller of said process cartridge when said process cartridge is mounted to the main assembly;
• a shaft substantially coaxial with said helical gear;
• and
• a twisted substantially triangular hole provided at an end of said shaft, wherein when said main assembly side gear rotates with said projection and hole engaged with each other, rotational driving force is transmitted from said main assembly side gear to said photosensitive drum through engagement between said projection and said hole with said hole being pulled into said projection, and the driving force is transmitted to said photosensitive drum through said shaft and is transmitted to said developing roller through said helical gear,
• wherein said hole, helical gear and shaft are made of integrally molded resin material, and an outer diameter D1 of said photosensitive drum, an outer diameter F of said shaft and a diameter C of a circumscribed circle of said projection, satisfy:
• D1>F.gtoreq.C, and
• wherein a spur gear is provided, at an end of said cylinder, for transmitting the driving force for rotating an image transfer roller in the main assembly when said process cartridge is mounted to the main assembly.

A process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driven rotatable member for receiving driving force from said motor and a twisted recess or projection having a non-circular cross-section and substantially coaxial with a rotation axis of said driven rotatable member, said process cartridge comprising:

• a rotatable electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted projection or recess provided at a longitudinal end of said photosensitive drum, having a non-circular cross-section and substantially coaxial with a rotation axis of said photosensitive drum, wherein said projection or recess of said photosensitive drum has such a dimension and configuration that said projection or recess can take a first relative rotational position with respect to said recess or projection of said driven rotatable member in which relative rotational movement therebetween is permitted, and a second relative rotational position with respect to said recess or projection of said driven rotatable member in which relative rotational movement is prevented in one rotational direction, while the rotation axis of said driven rotatable member and the rotation axis of said photosensitive drum are substantially aligned.

A process cartridge detachably mountable to a main assembly of an image forming apparatus, wherein said main assembly includes a motor, a driving rotatable member for receiving a driving force from said motor and a hole defined by twisted surfaces, said hole being substantially coaxial with said driving rotatable member, said process cartridge comprising:

• an electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted projection engageable with said twisted surfaces, said projection being provided at a longitudinal end of said photosensitive drum,
• wherein, when said driving rotatable member rotates with said hole and projection engaged with each other, a rotational driving force is transmitted from said driving rotatable member to said photosensitive drum through engagement between said hole and said projection.

A drive transmission part, for transmitting a driving force to an electrophotographic photosensitive drum and a developing roller for developing a latent image formed on said photosensitive drum, usable with an electrophotographic image forming apparatus for forming an image on a recording material, said apparatus including a motor, a driving rotatable member for receiving a driving force from said motor, and a hole defined by twisted surfaces, said hole being substantially coaxial with said driving rotatable member, said drive transmission part comprising:

• a transmission part gear for transmitting a driving force to said developing roller;
• a shaft substantially coaxial with said transmission part gear;
• and
• a twisted projection engageable with said twisted surfaces, said projection being provided at an end of said shaft,
• wherein said projection receives a driving force from said driving rotatable member through engagement between said hole and said projection, and wherein the driving force is transmitted to said photosensitive drum through the shaft, and is transmitted to said developing roller through said transmission part gear.

A photosensitive drum, usable with an electrophotographic image forming apparatus for forming an image on a recording material, said apparatus including a motor, a driving rotatable member for receiving a driving force from said motor, and a hole defined by twisted surfaces, said hole being substantially coaxial with said driving, said photosensitive drum comprising:

• a cylinder having a photosensitive layer thereon;
• and
• a drive transmission member mounted to an end of said cylinder, said transmission member including:
• a transmission member gear for transmitting a driving force from said driving rotatable member to a developing roller;
• a shaft substantially coaxial with said transmission member gear;
• and
• a twisted projection engageable with said twisted surfaces, said projection being provided at an end of said shaft,
• wherein said projection receives a driving force from said driving rotatable member through engagement between said hole and said projection, and wherein the driving force is transmitted to said photosensitive drum through the shaft, and is transmitted to said developing roller through said transmission member gear.

A process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving driving force from said motor and having a twisted recess or projection having a non-circular cross-section and being substantially coaxial with a rotation axis of said driving rotatable member, said process cartridge comprising:

• a rotatable electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted projection or recess provided at a longitudinal end of said photosensitive drum, having a non-circular cross-section and being substantially coaxial with a rotation axis of said photosensitive drum, wherein said projection or recess of said photosensitive drum has such a dimension and configuration that said projection or recess of said photosensitive drum can take a first relative rotational position with respect to said recess or projection of said driving rotatable member in which relative rotational movement therebetween is permitted, and a second relative rotational position with respect to said recess or projection of said driving rotatable member in which relative rotational movement is prevented in one rotational direction, while the rotation axis of said driving rotatable member and the rotation axis of said photosensitive drum are substantially aligned, and the photosensitive drum is urged in a longitudinal direction of said photosensitive drum by engagement between the recess or projection of the driving rotatable member and said projection or recess of said photosensitive drum.

A process cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image on a recording material, said main assembly including a motor, a driving rotatable member for receiving driving force from said motor and having a twisted recess or projection having a non-circular cross-section and being substantially coaxial with a rotation axis of said driving rotatable member, said process cartridge comprising:

• a rotatable electrophotographic photosensitive drum;
• process means actable on said photosensitive drum;
• and
• a twisted projection or recess provided at a longitudinal end of said photosensitive drum, having a non-circular cross-section and being substantially coaxial with a rotation axis of said photosensitive drum, wherein said projection or recess of said photosensitive drum has such a dimension and configuration that said projection or recess of said photosensitive drum can take a first relative rotational position with respect to said recess or projection of said driving rotatable member in which relative rotational movement therebetween is permitted, and a second relative rotational position with respect to said recess or projection of said driving rotatable member in which relative rotational movement is prevented in one rotational direction by engagement between the twisted recess or projection of the driving rotatable member and said twisted projection or recess of said photosensitive drum, while substantially aligning the rotation axis of said photosensitive drum with the rotation axis of said driving rotatable member and urging the photosensitive drum in a longitudinal direction of said photosensitive drum by engagement therebetween.