Gear unit, image forming apparatus and gear unit mounting method

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

• an image bearing member;
• image forming means for forming a toner image on said image bearing member;
• transfer means for transferring the toner image onto the recording material from said image bearing member;
• image fixing means for fixing on the recording material the toner image;
• feeding means for feeding the recording material;
• and
• a gear unit mountable to a frame of said image forming apparatus, said gear unit including an image bearing member driving gear for transmitting a driving force to said image bearing member;
• an image fixing means driving gear for transmitting a driving force to said image fixing means;
• a feed drive gear for transmitting a driving force to said feeding means;
• and a supporting member for integrally supporting said image bearing member driving gear via a gear shaft, said image fixing means driving gear and said feed drive gear, wherein when said gear unit is mounted to the frame of said image forming apparatus, an end of the gear shaft supporting said image bearing member driving gear is inserted into a hole of the frame, so that the gear shaft is supported by said supporting member and the frame.

An electrophotographic image forming apparatus, for forming an image on a recording material, to which a process cartridge having an image bearing member and process means actable on the image bearing member is detachably mountable, said apparatus comprising:

• mounting means for detachably mounting the process cartridge;
• transfer means for transferring a toner image onto the recording material from the image bearing member contained in the process cartridge mounted on said mounting means;
• image fixing means for fixing on the recording material the toner image transferred onto the recording material;
• feeding means for feeding the recording material;
• a motor for driving the image bearing member in the process cartridge, said image fixing means, and said feeding means;
• and
• a gear unit mountable to a frame of said image forming apparatus, said gear unit including an image bearing member driving gear for transmitting a driving force from said motor to the image bearing member;
• an image fixing means driving gear for transmitting a driving force from said motor to said image fixing means;
• a feed driving gear for transmitting a driving force from said motor to said feeding means;
• and a supporting member for integrally supporting said image bearing member driving gear via a gear shaft, said image fixing means driving gear, and said feed driving gear, wherein when said gear unit is mounted to the frame of said image forming apparatus, an end of the gear shaft supporting said image bearing member driving gear is inserted into a hole of the frame, so that the gear shaft is supported by said supporting member and the frame.

A mounting method for a gear unit usable with an electrophotographic image forming apparatus for forming an image on a recording material, the image forming apparatus including an image bearing member, an image fixing means for fixing on the recording material a toner image formed on the image bearing member and transferred to the recording material from the image bearing member, and feeding means for feeding the recording material, said method comprising the steps of:

• preparing a gear unit including an image bearing member driving gear for transmitting a driving force to the image bearing member;
• an image fixing means driving gear for transmitting a driving force to the image fixing means;
• a feed drive gear for transmitting a driving force to the feeding means;
• a supporting member for integrally supporting the image bearing member driving gear via a gear shaft, the image fixing means driving gear and the feed drive gear, wherein when the gear unit is mounted to a frame of the image forming apparatus, an end of the gear shaft supporting the image bearing member driving gear is inserted into a hole of the frame, so that the gear shaft is supported by the supporting member and the frame;
• and
• mounting said gear unit to the frame of the image forming apparatus so that the image bearing member driving gear, the image fixing means driving gear, and the feed drive gear are interposed between the frame and said supporting member with the image bearing member driving gear, the image fixing means driving gear, and the feed drive gear near to the frame.

A gear unit mountable to a frame of an electrophotographic image forming apparatus for forming an image on a recording material, the image forming apparatus including a photosensitive drum as a toner image bearing member, an image fixing nip, formed by an interface of a pressure roller with a cylindrical film rotatably disposed against a heater, at which a toner image formed on the photosensitive drum and transferred to the recording material from the photosensitive drum is fixed on the recording material, and a feeding roller for feeding the recording material through the image forming apparatus, said gear unit comprising:

• a photosensitive drum driving gear for transmitting a driving force to the photosensitive drum;
• a pressure roller driving gear for transmitting a driving force to the pressure roller;
• a feed drive gear for transmitting a driving force to the feeding roller;
• and
• a single-piece supporting member on which said photosensitive drum driving gear, said pressure roller driving gear, and said feed drive gear are each axially mounted via gear shafts, wherein when said gear unit is mounted to the frame of the image forming apparatus by fastening said single-piece supporting member to the frame by a screw, an end of a one of the gear shafts by which said photosensitive drum driving gear is mounted is inserted into a hole of the frame, so that the gear shaft is supported by said single-piece supporting member and the frame.

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

• a photosensitive drum as a toner image bearing member;
• a charging roller for charging said photosensitive drum;
• a developer for forming a toner image on said photosensitive drum, once said photosensitive drum has been charged;
• a charged transfer roller for pressing the recording material against said photosensitive drum in order to transfer the toner image onto the recording material from said photosensitive drum;
• an image fixing nip, formed by the interface of a pressure roller with a cylindrical film rotatably disposed against a heater, at which the toner image is fixed on the recording material;
• a feeding roller for feeding the recording material through said image forming apparatus;
• a gear unit comprising a photosensitive drum driving gear for transmitting a driving force to said photosensitive drum, a pressure roller driving gear for transmitting a driving force to said pressure roller, a feed drive gear for transmitting a driving force to said feeding roller, and a single-piece supporting member on which said photosensitive drum driving gear, said pressure roller driving gear, and said feed drive gear are each axially mounted via gear shafts, said gear unit to be mounted to a frame of said image forming apparatus by fastening said single-piece supporting member to said frame by a screw such that an end of a one of the gear shafts by which said photosensitive drum driving gear is mounted is inserted into a hole of the frame, so that the gear shaft is supported by said single-piece supporting member and the frame.

An electrophotoqraphic image forming apparatus for forming an image on a recording material, to which a process cartridge, having a photosensitive drum as a toner image bearing member and a processing mechanism actable on the photosensitive drum, is detachably mountable, comprising:

• a mounting interface at which the process cartridge is detachably mounted;
• a charged transfer roller for pressing the recording material against the photosensitive drum in order to transfer a toner image onto the recording material from the photosensitive drum contained in the process cartridge mounted to said mounting interface;
• a pressure roller interfacing with a cylindrical film, rotatably disposed against a heater, forming an image fixing nip at which the toner image is fixed on the recording material;
• a feeding roller for feeding the recording material through said image forming apparatus;
• a motor for driving the photosensitive drum, said pressure roller, and said feeding roller;
• a gear unit comprising a photosensitive drum driving gear for transmitting a driving force from said motor to the photosensitive drum, a pressure roller driving gear for transmitting a drive force from said motor to said pressure roller, a feed drive gear for transmitting a driving force from said motor to said feeding roller, and a single-piece supporting member on which said photosensitive drum driving gear, said pressure roller driving gear, and said feed drive gear are each axially mounted via gear shafts, said gear unit to be mounted to a frame of said image forming apparatus by fastening said single-piece supporting member to said frame by a screw such that an end of a one of the gear shafts by which said photosensitive drum driving gear is mounted is inserted into a hole of the frame, so that the gear shaft is supported by said single-piece supporting member and the frame.

A mounting method for a gear unit usable with an electrophotographic image forming apparatus for forming an image on a recording material, the image forming apparatus including a photosensitive drum as a toner image bearing member, an image fixing nip, formed by an interface of a pressure roller and a cylindrical film rotatably disposed against a heater, at which a toner image formed on the photosensitive drum and transferred to the recording material from the photosensitive drum is fixed on the recording material, and a feeding roller for feeding the recording material through the image forming apparatus, said method comprising the steps of:

• preparing said gear unit including a photosensitive drum driving gear for transmitting a driving force to the photosensitive drum, a pressure roller driving gear for transmitting a driving force to the pressure roller, a feed drive gear for transmitting a driving force to the feeding roller, and a single-piece supporting member on which said photosensitive drum driving gear, said pressure roller driving gear, and said feed drive gear are each axially mounted via gear shafts;
• and
• mounting said gear unit to a frame of the image forming apparatus by fastening said single-piece supporting member to the frame by a screw such that an end of a one of the gear shafts by which said photosensitive drum driving gear is mounted is inserted into a hole of the frame, so that the gear shaft is supported by said single-piece supporting member and the frame, and so that said gears are interposed between the frame and said single-piece supporting member with said gears near to the frame.