Process cartridge and electrophotographic image forming apparatus

An electrophotographic image forming apparatus usable with a process cartridge detachably mountable to a main assembly of said electrophotographic image forming apparatus, comprising:

• a first main assembly positioning portion;
• a second main assembly positioning portion;
• a third main assembly positioning portion;
• a main assembly driving force transmitting portion;
• and
• a mounting portion configured and positioned to detachably mount the process cartridge,
• wherein said process cartridge includes an electrophotographic photosensitive drum, a developing member configured and positioned to develop an electrostatic latent image formed on the electrophotographic photosensitive drum, a drum unit supporting the electrophotographic photosensitive drum, a developing unit supporting the developing member, a first portion to be positioned, which is coaxial with the electrophotographic photosensitive drum and which projects longitudinally outwardly of the electrophotographic photosensitive drum from the drum unit, the first portion to be positioned being positioned by said first main assembly positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein said first main assembly positioning portion is provided in the main assembly of the electrophotographic image forming apparatus, and wherein the first portion to be positioned supports a rotational drum shaft of the electrophotographic photosensitive drum, a second portion to be positioned, which is coaxial with the electrophotographic photosensitive drum and which projects longitudinally outwardly of the electrophotographic photosensitive drum from the drum unit, the second portion to be positioned being positioned by said second main assembly positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein said second main assembly positioning portion is provided in the main assembly of said electrophotographic image forming apparatus, and wherein the second portion to be positioned rotatably supports the rotational drum shaft, a third portion to be positioned projected in a downstream direction, with respect to a mounting direction in which the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, from the drum unit at a position downstream of the first portion to be positioned with respect to the mounting direction, the third portion to be positioned being positioned by said third main assembly positioning portion when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus,
• wherein said third main assembly positioning portion is provided in the main assembly of the electrophotographic image forming apparatus;
• a cartridge coupling, provided at one longitudinal end of the rotational drum shaft, configured and positioned to receive a rotational driving force for driving the electrophotographic photosensitive drum from the main assembly when the process cartridge is mounted to the main assembly of said electrophotographic image forming apparatus, wherein said cartridge coupling receives the rotational driving force in a longitudinal direction of the electrophotographic photosensitive drum;
• and
• a helical gear partly exposed through the drum unit between the first portion to be positioned and the third portion to be positioned with respect to the mounting direction,
• wherein the helical gear, when the process cartridge is mounted to said mounting portion of said electrophotographic image forming apparatus, receives a driving force for rotating the developing member from said main assembly driving force transmitting portion provided in the main assembly of said electrophotographic image forming apparatus.