Fixing device, image forming apparatus, and belt driving unit

摘要

A fixing device includes a first roller rotatable about a first axis of rotation, a second roller rotatable about a second axis of rotation, a fixing belt rotatably wound between the first roller and the second roller, and auxiliary rings. At least one of the rollers of the first roller and the second roller includes a rotation maintaining part configured to hold the fixing belt rotatably and a restricting flange protruding from an outer peripheral surface of each of opposite end parts in a direction of an axis of rotation of the rotation maintaining part. The auxiliary rings are located outside the opposite end parts in the direction of the axis of rotation of the rotation maintaining part, have an outer diameter larger than the restricting flange, and are rotatable independently of the restricting flange.

主权项

1. A fixing device, comprising:
a first roller rotatable about a first axis of rotation; a second roller rotatable about a second axis of rotation; a fixing belt rotatably wound between the first roller and the second roller; and auxiliary rings capable of coming into contact with the fixing belt and each configured to be rotated accompanied by rotation of the fixing belt in a state in which the fixing belt is in contact therewith, wherein at least one of the rollers of the first roller and the second roller includes a rotation maintaining part configured to hold the fixing belt rotatably and a restricting flange protruding from an outer peripheral surface of each of opposite end parts in a direction of an axis of rotation of the rotation maintaining part, the auxiliary rings are located outside the opposite end parts in the direction of the axis of rotation of the rotation maintaining part, have an outer diameter larger than the restricting flange, and are rotatable independently of the restricting flange, the fixing device further comprising: a support shaft; first bearings provided inside the at least one of the rollers, the support shaft passing through the first bearings; and second bearings provided inside the respective auxiliary rings, the support shaft passing through the second bearings, the at least one of the rollers is rotatably held at the support shaft through the first bearings, and each auxiliary ring is rotatably held at the support shaft through the corresponding second bearing.