Provided is a process cartridge where a developing unit includes a coupling member that receives driving force, a driving transmission member that transmits the driving force from the coupling member to a driving roller, and a support member that rotatably supports the coupling member and is movable with respect to a developing frame in a direction intersecting with a rotational axis of the developing roller. The developing frame and the driving transmission member are configured to be movable with respect to a drum frame of a drum unit in the direction intersecting the rotational axis. In this process cartridge, an urging member that engages with both the support member and the drum frame is included such that an urging force is applied in a direction in which a positioned portion of the support member and a positioning portion of the drum frame contact each other.

With a structure in which a coupling member includes a sphere providing a center of inclination (pivoting), a rotational force transmitted member has an opening have a diameter smaller than that of the sphere, and the coupling member is prevented from disengaging from rotational force transmitted member by contact of inner edge of the opening to the sphere, the inner edge of the opening may limit an inclinable (pivotable) angle range of the coupling member. In a state that a pin that is a shaft portion is inserted in a hole that is a through-hole provided in a coupling member, opposite end portions of the pin are supported by a driving side flange, which is a rotational force transmitted member. The coupling member, the driving side flange, and the pin are connected in this manner, and the pin contacts the inside of the hole without limiting the inclinable angle range.

A process cartridge includes a frame and a photosensitive drum supported by the frame, with the photosensitive drum being rotatable about an axis thereof. A coupling is operatively connected to the photosensitive drum such that a driving force can be transferred from the coupling to the photosensitive drum. A developing roller is supported by the frame, with the developing roller being rotatable about an axis thereof. A gear is positioned at a side of the process cartridge, with the gear being rotatable about an axis thereof. The gear has a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge, and with a tip of at least one of the exposed teeth facing the axis of the photosensitive drum. As measured in the axial direction of the photosensitive drum, the teeth of the gear are shorter than the projection of the coupling.

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.

A cartridge that is mountable to an apparatus main assembly of an image forming apparatus, the cartridge includes a developing roller; a frame supporting the developing roller; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame; and an elastic part provided between the frame and the movable part to urge the movable part. The movable part includes a first force receiving part that receives force from the apparatus main assembly, in a direction of moving from the first position to the second position, and a second force receiving part that receives force from the apparatus main assembly, in a direction of moving from the second position to the first position. When the movable part receives force from the apparatus main assembly at the first force receiving part and is at the second position, the movable part receives urging force from the elastic part in a direction of moving the movable part from the second position to the first position.

A driving-force transmission member includes a coupling portion that includes a driving-force transmission surface and that transmits a driving force to a cartridge coupling, a first helical gear portion that engages with a driven gear of a cartridge to transmit the driving force, and a second helical gear portion that engages with a drive gear to receive the driving force. The portions rotate integrally with each other when the driving-force transmission member rotates about the axis of rotation. The driving-force transmission surface is shaped with a twist in the same direction as the driving-force transmission member. Helical teeth of the first helical gear portion are shaped with a twist in the same direction as the driving-force transmission surface. Helical teeth of the second helical gear portion are shaped with a twist in a direction opposite to the twist direction of the helical teeth of the first helical gear portion.

To provide a process cartridge, a drum unit capable of receiving a driving force from the main assembly, and an image forming apparatus including the process cartridge. A cartridge is provided with a movable member having a driving force receiving portion. The movable member moves between an advanced position and a retracted position.

In a developing cartridge, a first supporting member is attached to a housing and has a first developing supporting portion and a driving-force-receiving-member supporting portion, the first developing supporting portion being configured to rotatably support a first part of a rotational shaft, the driving-force-receiving-member supporting portion being configured to rotatably support a driving-force-receiving member. The second supporting member is attached to the housing and has a second developing supporting portion and a detection-rotational-body supporting portion, the second developing supporting portion being configured to rotatably support a second part of the rotational shaft, the detection-rotational-body supporting portion being configured to rotatably support a detection rotational body.

A drive device that drives a detachable unit detachably attached to an image forming apparatus includes a drive coupling, a rotary shaft, a relay member, a contact member, and a compression spring. The drive coupling contacts and separate from a driven coupling of the detachable unit along with movement of the detachable unit. The relay member transmits rotation force of the rotary shaft to the drive coupling to rotate together. The compression spring has an axial end contacting the contact member disposed away from the driven coupling from the relay member and another axial end contacting the relay member. The drive coupling includes an outer circumferential restrictor restricts radial movement of the compression spring. The relay member includes an inner circumferential restrictor restricts radial movement of the compression spring.

A cartridge that is mountable to an apparatus main assembly of an image forming apparatus, the cartridge includes a developing roller; a frame supporting the developing roller; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame; and an elastic part provided between the frame and the movable part to urge the movable part. The movable part includes a first force receiving part that receives force from the apparatus main assembly, in a direction of moving from the first position to the second position, and a second force receiving part that receives force from the apparatus main assembly, in a direction of moving from the second position to the first position. When the movable part receives force from the apparatus main assembly at the first force receiving part and is at the second position, the movable part receives urging force from the elastic part in a direction of moving the movable part from the second position to the first position.