Toner conveyance device and image forming apparatus

Patent metadata

Field	Value
Publication number	US-2022011694-A1
Application number	US-202017429261-A
Country	US
Kind code	A1
Filing date	Jan 22, 2020
Priority date	Feb 7, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

An image forming apparatus (1) includes a casing (21) having a toner conveyance path (34); a screw (24) conveying a toner in the toner conveyance path (34) in a predetermined conveyance direction; and a downstream side bearing (25) rotatably supporting a downstream side end portion of the screw (24) in the conveyance direction, wherein the screw (24) includes: a shaft (51) extending in the conveyance direction; and a spiral fin (52) provided around an outer circumferential face of the shaft (51), the shaft (51) has a downstream side insertion part (54) inserted into the downstream side bearing (25), and the downstream side insertion part (54) has an outer diameter larger than an outer diameter of a downstream side end portion of the fin (52) in the conveyance direction.

First claim

1 . A toner conveyance device comprising:
a casing having a toner conveyance path; a screw conveying a toner in the toner conveyance path in a predetermined conveyance direction; and a downstream side bearing rotatably supporting a downstream side end portion of the screw in the conveyance direction, wherein the screw includes: a shaft extending in the conveyance direction; and a spiral fin provided around an outer circumferential face of the shaft, the shaft has a downstream side insertion part inserted into the downstream side bearing, and the downstream side insertion part has an outer diameter larger than an outer diameter of a downstream side end portion of the fin in the conveyance direction.

2 . The toner conveyance device according to claim 1 , wherein
a gap between the downstream side insertion part and the downstream side bearing is disposed radially outward from the downstream side end portion of the fin.

3 . The toner conveyance device according to claim 1 , wherein
the casing has a cylindrical duct extending in the conveyance direction, and the toner conveyance path is provided in the duct.

4 . The toner conveyance device according to claim 3 , wherein
a flange is protruded radially outward on a downstream side end portion of the duct in the conveyance direction, and the flange covers a gap between the downstream side insertion part and the downstream side bearing from an upstream side in the conveyance direction.

5 . The toner conveyance device according to claim 4 , wherein
a film-shaped seal member is disposed between the flange and the downstream side insertion part.

6 . The toner conveyance device according to claim 4 , wherein
a holder is protruded toward a downstream side in the conveyance direction on a radially outer end portion of the flange, and the downstream side bearing is held by the holder.

7 . The toner conveyance device according to claim 1 , wherein
the outer diameter of the downstream side insertion part is larger than an inner diameter of a downstream side end portion of the toner conveyance path in the conveyance direction.

8 . The toner conveyance device according to claim 1 , further comprising an upstream side bearing rotatably supporting an upstream side end portion of the screw in the conveyance direction, wherein
the shaft further has an upstream side insertion part inserted into the upstream side bearing, and the upstream side insertion part has an outer diameter smaller than an outer diameter of an upstream side end portion of the fin in the conveyance direction.

9 . The toner conveyance device according to claim 3 , wherein
the duct has a toner communication port on a downstream side in the conveyance direction.

10 . An image forming apparatus including the toner conveyance device according to claim 1 .

Assignees

• Kyocera Document Solutions Inc

Inventors

• Mizutani Naoki
• Tomimori Koshiro

Classifications

• G03G2215/0838

  Circulation of developer in a closed loop within the sump of the developing device · CPC title

• G03G2215/0827

  Augers · CPC title

• G03G15/0898

  for preventing toner scattering during operation, e.g. seals (sealing the donor member G03G15/0817; sealing the magnetic brush G03G15/0942) · CPC title

• G03G15/0893 Primary

  in a closed loop within the sump of the developing device · CPC title

• G03G21/105

  Arrangements for conveying toner waste · CPC title