Image forming apparatus provided with fixing unit having mechanism capable of selectively executing driving of roller or operation of varying fixing nip pressure by switching rotation direction of one driving input gear

Patent metadata

Field	Value
Publication number	US-9671732-B2
Application number	US-201514929896-A
Country	US
Kind code	B2
Filing date	Nov 2, 2015
Priority date	Nov 18, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

In an image forming apparatus including a fixing unit and a storage part, the fixing unit includes: two rollers forming a fixing nip part; a pressure adjustment mechanism varying fixing nip pressure; one driving input gear receiving: a rotational power in a first direction for driving the two rollers and a rotational power in a second direction for actuating the pressure adjustment mechanism; and a gear cover supporting, with a long hole, a bearing supporting a rotary shaft of the driving input gear. The gear cover has a convex part, and the storage part has a receiving part supporting the bearing of the driving input gear at time of insertion of the fixing unit. The receiving part has a concave part fitted with the convex part of the gear cover moving with respect to the bearing of the driving input gear at the time of insertion of the fixing unit.

First claim

What is claimed is:

1. An image forming apparatus comprising a fixing unit and a storage part into which the fixing unit is inserted, wherein
the fixing unit comprises:
two rollers forming a fixing nip part;
a pressure adjustment mechanism varying fixing nip pressure between the two rollers;
a driving input gear to which a rotational power in a first direction driving the two rollers and a rotational power in a second direction rotating in the direction opposite to the first direction and actuating the pressure adjustment mechanism are transmitted from a driving source outside of the fixing unit; and
a gear cover being formed with a hole supporting a bearing supporting a rotary shaft of the driving input gear and supporting the bearing in a state in which the bearing penetrates through the hole and is projected in a direction in which the rotary shaft extends,

the gear cover has a cover side engagement part extending in a direction perpendicular to an insertion direction of the fixing unit,
formed at the storage part is a receiving part supporting a portion of the bearing of the driving input gear projected from the gear cover, being formed in a manner so as to extend in the insertion direction of the fixing unit and so that a length of the receiving part in a direction orthogonal to the insertion direction is substantially equal to a length of the bearing in the direction orthogonal to the insertion direction, and receiving the bearing while guiding movement of the bearing in the insertion direction when the fixing unit is inserted into the storage part, and
the receiving part is provided with a storage side engagement part engaging with the cover side engagement part to regulate the movement of the bearing in the insertion direction when the receiving part is guiding the movement.

2. The image forming apparatus according to claim 1 , wherein the receiving part guides the movement of the bearing in the insertion direction while regulating movement of the bearing in the perpendicular direction.

3. The image forming apparatus according to claim 1 ,
wherein the hole formed at the gear cover is a long hole supporting the bearing in a state in which the bearing is movable in the perpendicular direction, and
the cover side engagement part is a convex part, and the storage side engagement part is a concave part.

4. The image forming apparatus according to claim 1 , wherein the cover side engagement part is a concave part, and the storage side engagement part is a convex part.

5. The image forming apparatus according to claim 1 , wherein the fixing unit further comprises a transmission mechanism of: transmitting the rotational power in the first direction to the two rollers without actuating the pressure adjustment mechanism when the rotational power in the first direction is given to the driving input gear; and not transmitting the rotational power in the second direction to the two rollers while actuating the pressure adjustment mechanism when the rotational power in the second direction opposite to the first direction is given to the gear.

6. The image forming apparatus according to claim 1 , wherein the cover side engagement part is arranged adjacently to the hole.

7. The image forming apparatus according to claim 1 ,
wherein the fixing unit includes a fixing screw and a screw hole, and
the storage part has a fixing part capable of screwing the fixing screw via the screw hole in a state in which the fixing unit is stored in the storage part and the storage side engagement part engages with the cover side engagement part.

Assignees

• Kyocera Document Solutions Inc

Inventors

• Fukunaga Yasuyuki

Classifications

• G03G15/2064 Primary

  combined with pressure · CPC title