JPH0687718U - Bearing device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an extremely inexpensive bearing device as compared with a bearing made of a special resin composition or a bearing having a complicated structure. [Structure] The end portions 1a, 1a 'of the rotating roll 1 are supported by heat-resistant synthetic resin bearings 4, 4', and the end portions 1a, 1a are also supported.
The polytetrafluoroethylene layer 7 is formed by coating both sides or one side surface of the a'and the synthetic resin bearings 4, 4'with polytetrafluoroethylene.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing device, and more particularly to a bearing device suitable for axially supporting a rotating roll of a fixing device used in a copying machine or a laser printer.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, in order to fix a toner image on a support such as paper, a fixing device in which a hollow heating roll having a heating source inside and an elastic pressure roll are combined has been used.

As a bearing device for such a rotating roll of a fixing device, particularly for a heating roll, conventionally, a bearing made of a special heat-resistant resin excellent in lubricity is mounted on a metal frame, and the end of the rotating roll is attached to the bearing. A ball bearing with heat-resistant grease is attached to a metal frame, and a rotating roll is attached to this ball bearing via a heat insulating bush.

[0004]

[Problems to be solved by the device]

 However, such a conventional bearing device has a problem that it becomes extremely expensive because it uses a special resin composition or has a complicated structure.

In particular, in recent years, the image forming apparatus has been downsized, and the use in personal and general households has increased. When the fixing unit is detachable by a cassette method and the fixing unit fails, the user himself / herself can fix the fixing unit. Replacing a defective fixing unit has made it possible to dispose of the fixing unit once it is broken, and reducing the cost of the fixing unit has become an extremely important issue.

An object of the present invention is to solve the above problems of the conventional bearing device and provide an inexpensive bearing device.

[0007]

[Means for Solving the Problems]

 The inventors of the present invention have conducted various studies to achieve the above object, and as a result, the bearing is made of a general-purpose heat-resistant synthetic resin and the bearing sliding portion of the rotating roll is coated with polytetrafluoroethylene. Then, they found that a bearing device that can withstand sufficient use was obtained, and completed the present invention.

That is, according to the present invention, the end of the rotating roll is supported by the heat-resistant synthetic resin bearing, and both ends or one surface of the rotating roll end and the synthetic resin bearing are coated with polytetrafluoroethylene. Is a bearing device.

[0009]

【Example】

 An embodiment of the bearing device of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an example of a fixing device provided with the bearing device of the present invention, and FIG. 2 is an exploded perspective view thereof.

In FIGS. 1 and 2, 1 is a heat fixing roll, and 2 is a pressure roll, which are rotatably attached to bearings 4 and 4 ′ of the metal frame 3, respectively. Reference numerals 5 and 5 ′ are pressure springs for pressing the pressure roll 2 against the heat fixing roll 1, and 6 is a gear for transmitting a rotational force to the heat fixing roll 1.

The surfaces of both end portions (bearing sliding portions) 1a, 1a 'of the heat fixing roll 1 are covered with polytetrafluoroethylene to form polytetrafluoroethylene layers 7, 7'.

The synthetic resin forming the bearings 4 and 4 ′ can be selected from general-purpose heat-resistant synthetic resins, for example, polybutylene terephthalate, glass fiber reinforced polyethylene terephthalate, polyether sulfone, polyphenylene sulfide, polyaryle. Polyamide, polyamideimide, polyetheretherketone, polyimide, etc. are preferably used.

If the metal frame 3 is formed of the above heat-resistant synthetic resin and the bearings 4, 4 ′ are formed integrally with the frame 3, the number of parts can be reduced, which contributes to cost reduction. is there.

The resin coating both end portions 1a, 1a ′ of the heat fixing roll 1 needs to be polytetrafluoroethylene, and even the same fluororesin may be another resin such as tetrafluoroethylene-perfluoroalkyl vinyl ether. When coated with a copolymer resin (PFA), the amount of wear is large and a satisfactory result cannot be obtained. A suitable thickness of the polytetrafluoroethylene layer 7 is usually 10 μm or more.

The heat fixing roll 1 may have a surface coated with polytetrafluoroethylene in order to improve the peeling property of the paper and prevent stains. In such a case, the coating region of polytetrafluoroethylene is used. Should be expanded to the bearing sliding portions 1a, 1a 'at both ends.

The coating with polytetrafluoroethylene is usually performed by coating, but it may be coated with a polytetrafluoroethylene tube.

Instead of coating the ends 1a, 1a ′ of the heat fixing roll 1 with polytetrafluoroethylene, the bearings 4, 4 ′ may be coated with polytetrafluoroethylene.

In the above description, an example in which the bearing device of the present invention is used for the heat fixing roll of a fixing device such as a copying machine or a laser printer has been described. However, the present invention is not limited to this, and the rotating device is not limited thereto. It can be widely used in various devices as a roller bearing device.

[0019]

[Effect of device]

 According to the present invention, there is no need to use a special resin composition or a bearing having a complicated mechanism, and an inexpensive bearing device can be provided.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a fixing device provided with a bearing device of the present invention.

FIG. 2 is an exploded perspective view of the bearing device shown in FIG.

[Explanation of symbols]

 1 Heat Fixing Roll (Rotating Roll) 1a, 1a 'Roll Ends 4, 4' Heat Resistant Synthetic Resin Bearing 7, 7 'Polytetrafluoroethylene Layer

Claims (2)

[Scope of utility model registration request] 1. The end of the rotating roll is supported by a heat-resistant synthetic resin bearing, and both ends or one surface of the end of the rotating roll and the synthetic resin bearing are coated with polytetrafluoroethylene. Bearing device. 2. The bearing device according to claim 1, wherein the rotating roll is a heating roll, and the end surface of the rotating roll is coated with polytetrafluoroethylene.