Powder pump capable of effectively conveying powder and image forming apparatus using powder pump

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey the powder enclosed in the cavity while moving the cavity,
• wherein (−0.18≦(RB−SN+SX)/2−(RA−SN))≦0.16)
• is satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey the powder enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.4),
• (RB−(SN+SX)/2≧0.4), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey the powder enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.5),
• ((RB−(SN+SX)/2)≧0.5), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey the powder enclosed in the cavity while moving the cavity,
• wherein (0.9≦(SN/2SR)≦0.95)
• is satisfied when a minimum inner diameter of the through hole of the stator, and a radius of each groove of the through hole of a cross section of the stator are in millimeters and represented by SN, and SR, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey toner enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.45), and
• (RB−(SN+SX)/2≧0.45)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters are represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey toner enclosed in the cavity while moving the cavity,
• wherein (−0.18≦RB−(SN+SX)/2−(RA−SN)≦0.16)
• is satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey toner enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.4),
• (RB−(SN+SX)/2≧0.4), and
• (−0.18≦RB−SN+SX)/2−(RA−SN)≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey toner enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.5),
• (RB−(SN+SX)/2≧0.5), and
• (−0.18≦RB−(SN+SX)/2−(RA−SN)≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey toner enclosed in the cavity while moving the cavity,
• wherein (0.9≦(SN/2SR)≦0.95)
• is satisfied when a minimum inner diameter of the through hole of the stator, and a radius of each groove of the through hole of a cross section of the stator are in millimeters and represented by SN, and SR, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey a developer including toner and a carrier enclosed in the cavity while moving the cavity,
• wherein ((RA−SN)≧0.45) and
• ((RB−(SN+SX)/2)≧0.45)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey a developer including toner and a carrier enclosed in the cavity while moving the cavity, wherein (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.16)
• is satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey a developer including toner and a carrier enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.4),
• ((RB−(SN+SX)/2)≧0.4), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey a developer including toner and a carrier enclosed in the cavity while moving the cavity,
• wherein ((RA−SN)≧0.5),
• ((RB−(SN+SX)/2)≧0.5), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

An image forming apparatus, comprising:

• an image bearing member on which an electrostatic latent image is formed;
• and
• a powder pump comprising:
• a stator comprised of a through hole, the through hole comprising two spirally extended grooves, and
• a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, the rotor being configured to convey a developer including toner and a carrier enclosed in the cavity while moving the cavity,
• wherein (0.9≦(SN/2SR)≦0.95)
• is satisfied when a minimum inner diameter of the through hole of the stator, and a radius of each groove of the through hole of a cross section of the stator are in millimeters and represented by SN, and SR, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor means rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein ((RA−SN)≧0.45) and
• ((RB−(SN+SX)/2)≧0.45)
• are satisfied when a diameter of a cross section of the rotor means, an outer diameter of the rotor means, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor means rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.16)
• is satisfied when a diameter of a cross section of the rotor means, an outer diameter of the rotor means, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor means rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein ((RA−SN)≧0.4),
• ((RB−(SN+SX)/2)≧0.4), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor means, an outer diameter of the rotor means, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor means rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.5),
• ((RB−(SN+SX)/2)≧0.5), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor means, an outer diameter of the rotor means, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A powder pump, comprising:

• a stator comprised of a through hole, the through hole comprising two spirally extended grooves;
• and
• a rotor means rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity, wherein
• (0.9≦(SN/2SR)≦0.95)
• is satisfied when a minimum inner diameter of the through hole of the stator, and a radius of each groove of the through hole of a cross section of the stator are in millimeters and represented by SN, and SR, respectively.

A method for conveying a powder with a powder pump, comprising:

• providing a stator comprised of a through hole having two spirally extended grooves;
• and
• providing a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.45) and
• (RB−(SN+SX)/2≧0.45)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A method for conveying a powder with a powder pump, comprising:

• providing a stator comprised of a through hole having two spirally extended grooves;
• and
• providing a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein (−0.18≦(RB−SN+SX)/2−(RA−SN))≦0.16)
• is satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A method for conveying a powder with a powder pump, comprising:

• providing a stator comprising a through hole having two spirally extended grooves;
• and
• providing a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity,
• wherein (RA−SN≧0.4),
• ((RB−(SN+SX)/2)≧0.4), and
• (−0.18≦((RB−(SN+SX)/2−(RA−SN)))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A method for conveying a powder with a powder pump, comprising:

• providing a stator comprised of a through hole having two spirally extended grooves;
• and
• providing a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity, wherein
• (RA−SN≧0.5),
• ((RB−(SN+SX)/2)≧0.5), and
• (−0.18≦(RB−(SN+SX)/2−(RA−SN))≦0.12)
• are satisfied when a diameter of a cross section of the rotor, an outer diameter of the rotor, a minimum inner diameter of the through hole of the stator, and a maximum inner diameter of the through hole of the stator are in millimeters and represented by RA, RB, SN, and SX, respectively.

A method for conveying a powder with a powder pump, comprising:

• providing a stator comprised of a through hole having two spirally extended grooves;
• and
• providing a rotor rotatably provided to the through hole of the stator and spirally extended such that a cavity to convey a powder is formed between an outer peripheral surface of the rotor and an inner peripheral surface of the through hole of the stator, for conveying the powder enclosed in the cavity while moving the cavity, wherein
• 0.9≦(SN/2SR)≦0.95
• is satisfied when a minimum inner diameter of the through hole of the stator, and a radius of each groove of the through hole of a cross section of the stator are in millimeters and represented by SN, and SR, respectively.