WO2008001831A1

WO2008001831A1 - Rotating member support structure of fixing device and rolling bearing used for the structure

Info

Publication number: WO2008001831A1
Application number: PCT/JP2007/062963
Authority: WO
Inventors: Masaaki Honda
Original assignee: Ntn Corporation
Priority date: 2006-06-30
Filing date: 2007-06-28
Publication date: 2008-01-03

Abstract

Provided are a rotating member support structure for a fixing device and a rolling bearing used for the structure. The structure rotatably supports shaft parts of a rotating member by bearings that are fitted on the shaft parts by clearance fit, is capable of preventing creep and abnormal noise from occurring for a long period, and, as required, renders separate grounding means unnecessary. The structure has the shaft parts (9a) of the rotating member of the fixing device and also has the bearings (1) fitted on the shaft parts (9a) by clearance fit to rotatably support the shaft parts (9a). Coating having low-friction sliding properties is formed on at least either the shaft parts (9a) or the bearings (1), on at least portions coming into contact with the other members by fitting. The thickness of the coating is 2 to 10 μm, and the coefficient of dynamic friction at the portions where the bearings and the shaft parts are in contact with each other and where the coating is formed is 0.2 or less.

Description

Specification

Rotating member support structure of fixing device and rolling bearing used in this structure

The present invention relates to a shaft portion of a rotating member such as a fixing roller and a pressure roller of a fixing device for office equipment.

The present invention also relates to a rotating member support structure that is rotatably supported by a bearing fitted with a clearance fit, and a rolling bearing used in this structure. In particular, the present invention relates to a structure that prevents the generation of abnormal noise at the fitting portion.

Background art

[0002] Rotating members such as fixing rollers and pressure rollers incorporated in office machines such as copiers and printers have rolling shafts whose shafts (shafts) are rolling bearings due to problems of assembly due to downsizing and structural simplicity. Many of the inner and outer rings are fitted with a clearance fit (loose fit). For this reason, depending on the use conditions, there is a risk that creep will occur between the shaft and the race that are fitted by clearance fitting. Conventionally, in order to prevent wear of the fitting portion due to creep, there is a rolling bearing in which an oxide film is formed on the fitting portion of the race (see, for example, Patent Document 1). Further, as an improvement method from the surface of the fixing roller support structure, there is a method in which a fluorine resin film is formed on the bearing mounting portion of the surface of the fixing roller (see Patent Document 2). In Patent Document 1, when applied to a rolling bearing that supports a fixing roller that undergoes a thermal cycle, the oxide film also has an effect of preventing wrinkles due to condensation. In addition, due to the clearance fit between the shaft portion of the rotating member and the bearing, there is a problem in that abnormal noise such as a squeak noise is generated at the fitting portion during printing. Conventionally, the fitting V, grease is applied to the part, and the noise is prevented by press-fitting into the shaft.

On the other hand, a fixing roller of a copying machine or a printer that fixes toner on printing paper with heat and pressure is formed hollow with a metal material such as steel or aluminum, and is heated from the inside by electromagnetic induction heating. There is an IH (Induction Heating) system. In such a fixing roller, the roller is charged by an internal current (electromagnetic wave noise) generated by electromagnetic induction, and the quality of printed matter is deteriorated. For this reason, in order to release the charged electricity by grounding the roller, conventionally, for example, a conductive bearing is used as a bearing for supporting the shaft portion, and the roller is interposed via the bearing. Grounded.

[0004] In recent years, a fixing unit of a fixing device is required to have a function of fixing toner to paper and high-quality printing faster as printing speed increases and image quality increases. The ambient temperature (and bearings) inevitably rises as the speed increases with the high speed to increase the fixing speed to the paper. In addition, since the service life of the equipment has been extended, the bearings used for this are required to have a high temperature and long life. As the temperature of the fixing portion and the bearing rises, the above-mentioned fitting and the noise at the portion are more likely to occur.

[0005] When the shaft portion of the rotating member is press-fitted into the bearing in order to prevent abnormal noise while pressing, it is effective in preventing abnormal noise due to the interference fit, but the assembly workability is significantly reduced. There's a problem.

On the other hand, when grease is applied to the fitting part, the assembly workability does not decrease that much, but since the fixing part becomes high temperature, it deteriorates over time due to deterioration of the grease over time (decrease in oil content, drought). There is a problem that sound and creep occur. In addition, the applied grease may scatter and contaminate the surrounding area.

When conductivity is required, conductive grease is sealed in the bearing, and conductive grease is also applied between the inner surface of the bearing and the shaft. However, in this case as well, there is a problem in that the quality of the printed matter is deteriorated because noise and tally are generated due to the deterioration of the conductive dulling with time and the grounding performance is also deteriorated.

[0006] In addition, the rolling bearing in which an oxide film is formed on the fitting portion of the bearing ring described in Patent Document 1 can prevent wear at the fitting portion, but has a large dynamic friction coefficient and is likely to generate abnormal noise. There's a problem. In addition, when used for supporting a charging rotating member such as a fixing roller, the oxide film is not conductive. For this reason, there is a problem that the rotating member cannot be grounded via the bearing, and a separate grounding means is required.

With the fixing roller support structure of Patent Document 2, it is possible to prevent wear and prevent abnormal noise caused by wear. However, due to problems in assembly due to downsizing of the fixing device and simplification of structure in recent years, when the fixing roller is supported by a clearance-fitted bearing, wear is directly affected by the mechanism shown in FIG. 4 to be described later. Abnormal noise may occur other than the cause. Patent Document 1: Japanese Patent Laid-Open No. 2001-140901

Patent Document 2: JP-A-7-168472

Disclosure of the invention

Problems to be solved by the invention

The present invention has been made to cope with such a problem, and has a structure in which a shaft portion of a rotating member in a fixing device is rotatably supported by a bearing fitted to the shaft portion by a clearance fit. An object of the present invention is to provide a rotating member support structure of a fixing device that can prevent creep and abnormal noise over a long period of time and does not require a separate grounding means as required, and a rolling bearing used in this structure.

Means for solving the problem

[0008] The rotating member support structure of the present invention includes a rotating member including a shaft portion of the rotating member in the fixing device and a bearing that is fitted into the shaft portion of the rotating member with a clearance fit and rotatably supports the shaft portion. In the rolling member support structure, a coating having a low friction sliding property is formed on a portion of at least one member of the shaft portion of the rotating member and the bearing that comes into contact with the other member by fitting, The coating film has a thickness of 2 to 10 / zm, and a dynamic friction coefficient at a contact portion of the shaft portion of the bearing and the rotating member on which the coating film is formed is 0.2 or less.

Here, the dynamic friction coefficient at the contact portion between the shaft portion of the bearing and the rotating member on which the coating is formed is a dynamic friction coefficient at the fitting surface of both members. Specifically, (1) when a coating is formed only on the bearing, this is the dynamic friction coefficient at the contact surface between the coating and the shaft of the rotating member, and (2) the coating only on the shaft of the rotating member. Is the dynamic friction coefficient at the contact surface between the coating and the bearing. (3) When the coating is formed on the shaft portion of the bearing and the rotating member, the dynamic friction at the contact surface between the coatings of the respective members It is a coefficient.

[0010] The film is a non-conductive film. The coating is a polytetrafluoroethylene (hereinafter referred to as PTFE) coating, molybdenum disulfide (hereinafter referred to as MoS) coating.

It is characterized by being a 2 film or a tungsten disulfide tungsten (hereinafter referred to as WS) film.

2

[0011] The film is a conductive film. The coating is a nickel-polytetrafluoroethylene (hereinafter referred to as Ni-PTFE) composite coating, or a graphite coating. It is a film.

[0012] When a radial load of 220 N is applied to the bearing and the rotating member is rotated at 130 rpm for 500 hours, dynamic friction is generated at the contact portion between the bearing on which the coating is formed and the shaft portion of the rotating member. The coefficient is 0.2 or less.

[0013] The rotating member is a fixing roller with a built-in heater for fixing the toner on the printing paper.

[0014] In the rolling bearing of the present invention, a plurality of rolling elements are arranged between the raceways of the inner ring and the outer ring, and the rotating member of the fixing device is rotatably supported. The shaft portion of the rotating member has an inner diameter of the inner ring. The coating is formed on the inner diameter surface of the inner ring or the outer diameter surface of the outer ring where the shaft portion of the rotating member is fitted with the clearance fit. It is characterized by.

The invention's effect

[0015] The rotating member support structure of the present invention is fitted at least in the shaft portion of the rotating member and at least one member of the bearing that is fitted to the shaft portion with a clearance fit and rotatably supports the shaft portion. As a coating having a low frictional sliding property at the portion that contacts the other member, the thickness is 2 to 10 / ζ πι, and at the contact portion of the shaft portion of the bearing and the rotating member on which the coating is formed. A film with a dynamic friction coefficient of 0.2 or less is formed. For this reason, the coefficient of dynamic friction on the mating surface is stabilized to a low level over a long period (for example, 500 hours), and creep and noise can be prevented. In addition, the formation of a coating prevents the application of grease on the mating surfaces, thus preventing contamination due to grease scattering to the surroundings.

In addition, it can contribute to the miniaturization of the fixing device and the abolition of anti-noise and creep prevention measures such as grease application and press-fitting to the shaft.

[0016] Since the above film is a PTFE film, a MoS film, or a WS film, it is compared with an oxide film.

twenty two

Therefore, the dynamic coefficient of friction force on the mating surface is less likely to generate abnormal noise.

[0017] The film is a conductive film such as a Ni-PTFE composite film or a graphite film. For this reason, for example, by encapsulating conductive grease in the bearing, the support structure itself can serve as a grounding mechanism, and a separate grounding means can be dispensed with.

BEST MODE FOR CARRYING OUT THE INVENTION [0018] The configuration of the fixing device is photosensitive → conveyance → development → fixing → discharge, and the fixing unit has two hollow rubber rollers (using aluminum or steel for the core metal) and temperature (about 200 ° C). It consists of a bearing and a heater that support Usually, since the roller is hollow, it is heated directly from inside the roller through a heater. In addition to the above temperature, pressure (about 98 N) is applied to fix the toner on the paper in order to fix the toner on the paper coming out of the development section.

A mechanism for generating abnormal noise such as squealing between the shaft portion of the rotating member and the bearing, that is, the fitting portion, during operation of the fixing device will be described with reference to FIG. FIG. 4 is a cross-sectional view when the shaft (shaft portion) of the fixing roller is fitted with a clearance fit on the inner ring inner surface of the rolling bearing. Fig. 4 (a) shows the case where only the temperature is applied to the fitting part, and Fig. 4 (b) and Fig. 4 (c) show the case where the fitting and the part are applied with temperature and load (pressure). .

[0019] As shown in Fig. 4 (a), the shaft thermally expands due to temperature rise, and the bearing inner ring moves together with the shaft (because the dynamic friction coefficient of the contact surface is large).

As shown in Fig. 4 (b), the shaft bends (curves) due to the radial load. In the figure, Fr represents the radial force applied to the bearing, and Fa represents the axial force applied to the bearing. Here, in the case of Fr and Fa, the posture of the bearing inner ring is maintained. As shown in Fig. 4 (c), Fr changes due to misalignment (eccentricity) between the shaft and the outer diameter of the fixing roller. When Fr> Fa, the inner ring posture of the bearing is broken. When the bearing posture returns to the original position, a squealing noise is generated.

In the above mechanism, when the dynamic friction coefficient on the mating surface between the shaft and the bearing is sufficiently small, Fr becomes Fa, and the attitude of the bearing can be maintained.

In the present invention, a coating film having predetermined characteristics is formed on the surface of the shaft portion of the rotating member, the inner ring inner surface of the bearing, etc., and the dynamic friction coefficient on the fitting surface is reduced over the service life required for the fixing device. It was found that squealing can be prevented over the durability period by maintaining. The present invention is based on such knowledge.

[0020] A rotating member support structure according to an embodiment of the present invention will be described with reference to Figs. FIG. 1 is a longitudinal sectional view of a rotating member support structure of a fixing device using a deep groove ball bearing. Fig. 2 is an enlarged view of the support structure in Fig. 1, with low friction on the shaft of the rotating member. The case where the film which has slidability is formed is shown.

As shown in FIG. 1, the fixing roller 9 that is a rotating member is made of aluminum and is hollow, and is heated up to about 200 ° C. by a heater 10 disposed in the hollow portion. The heater 10 may be a halogen heater or an electromagnetic induction heater. When an electromagnetic induction heater is used, the fixing roller 9 is charged by an internal current generated by electromagnetic induction.

As shown in FIG. 2, the shaft portions 9a at both ends of the fixing roller 9 are fitted to the inner surface of the inner ring 2 of the deep groove ball bearing 1 by a clearance fit, and the outer ring 3 of the deep groove ball bearing 1 is fixed to the frame 11 of the fixing device. I'll be angry. A coating 8 having a low friction sliding property is formed on the surface of the shaft 9 a of the fixing roller 9. The coating 8 may be formed on at least the entire shaft portion or the entire rotating member as long as it is formed at a contact portion with the bearing such as the deep groove ball bearing 1 or the like.

In the rotating member support structure of the present invention, the coating 8 may be formed on at least one of the shaft portion of the rotating member and the bearing. Therefore, as shown in FIG. 2, it may be formed only on the shaft portion 9a of the fixing roller 9, or may be formed only on the inner surface of the inner ring 2 of the deep groove ball bearing 1, or may be formed on both members. In the rotating member support structure of the present invention, it is not necessary to apply grease on the mating surfaces due to the formation of the film.

[0022] When the fixing roller support structure needs to be conductive, such as using the above-described electromagnetic induction system as a heater for the fixing roller, the coating film 8 can be used by adopting a conductive one. The shaft portion 9 a is grounded to the frame 11 through the coating 8 and the deep groove ball bearing 1, so that the electricity charged in the fixing roller 9 can be released.

Further, the bearing used in the rotating member support structure of the present invention is not limited to the rolling bearing as shown in FIGS. 1 and 2, and may be a sliding bearing.

A rolling bearing according to an embodiment of the present invention will be described with reference to FIG. Fig. 3 is a cross-sectional view of a deep groove ball bearing in which a lubricated dull is enclosed, and shows a case where a coating having low friction sliding properties is formed on the inner surface of the inner ring.

As shown in FIG. 3, the deep groove ball bearing 1 has an inner ring 2 having an inner ring rolling surface 2a on the outer circumferential surface and an outer ring 3 having an outer ring rolling surface 3a on the inner circumferential surface. A plurality of rolling elements 4 are arranged between 2a and the outer ring rolling surface 3a. The holding member that holds the plurality of rolling elements 4 Seal members 6 that are fixed to the cage 5 and the outer ring 3 are provided at the openings at both ends in the axial direction of the inner ring 2 and the outer ring 3, respectively. Lubricating grease 7 is sealed at least around the rolling elements 4.

A coating 8 having a low friction sliding property is formed on the inner diameter surface 2b of the inner ring 2 into which the shaft portion of a rotating member such as a fixing roller or a pressure roller is fitted with a clearance fit.

In the embodiment described above, the shaft portion of the rotating member is fitted to the inner diameter surface of the inner ring 2. However, in the rolling bearing of the present invention, the shaft portion is fitted to the outer diameter surface 3 b of the outer ring 3. It can also be applied to a rotating member support structure.

The rolling bearing of the present invention can also be used to support a rotating member other than a fixing roller that is charged by static electricity or the like.

[0025] The coating having low friction sliding property in the present invention has a dynamic friction coefficient at the contact portion of the shaft portion of the bearing and the rotating member on which the coating is formed, that is, a dynamic friction coefficient on the mating surface is 0.2 or less. If there is, it can be adopted. The coefficient of dynamic friction on the mating surface is 0.

Exceeding 2 will cause the inner ring posture of the bearing to collapse (see Fig. 4 (c)), and abnormal noise (squeaking noise) will easily occur.

Examples of such a film having low friction sliding property include a non-conductive film such as a PTFE film, a MoS film, and a WS film.

twenty two

In addition, when the support structure requires conductivity, a film having conductivity in combination with low friction sliding property is used. Examples of the conductive film include a composite film in which a metal powder is blended with fluorine resin and a graphite film. An example of a composite film in which metal powder is mixed with fluorine resin is a Ni-PTFE composite film in which metal powder is mixed with PTFE resin.

[0026] Examples of the method for forming a coating on the shaft portion of the rotating member and the inner ring inner surface or the outer ring outer surface of the bearing include electric plating, electroless plating, vacuum deposition, ion plating, and sputtering. Physical vapor deposition (PVD), chemical vapor deposition (CVD), etc., coating using a resin dispersion, coating by spraying, spraying, etc., and other known film forming methods can be employed.

In the present invention, a graphite coating, MoS coating, WS coating or the like is formed. In this case, it is preferable to employ sputtering because the film thickness can be made uniform. In addition, when forming a Ni-PTFE composite coating, the film thickness can be made uniform and the dimensional accuracy is excellent, and heat resistance, wear resistance, and slidability are excellent, and PTFE particles are uniformly dispersed in the film. What is possible It is preferable to employ electroless plating.

[0027] The thickness of the coating having low friction sliding property in the present invention is 2 to 10 μm. Preferably, it is 2-5 μm. By setting the film thickness to 2 m or more, as a practical use condition in office equipment such as copiers and printers, the fixing roller is rotated at 130 rpm for 500 hours while applying a radial load of 220 N to the bearing. Even at this point, the dynamic friction coefficient on the mating surface can be kept below 0.2 and noise can be prevented.

If the thickness of the coating is less than 2 μm, sliding between metals at the fitting part cannot be prevented sufficiently, and abnormal noise may occur. If it exceeds 10 / z m, the fitting accuracy between the shaft portion of the rotating member and the bearing will be lowered, and the cost for forming the coating will increase.

[0028] When a coating is formed on the inner ring inner surface or the outer ring outer diameter surface of the bearing, the thickness of the coating adhering to the raceway surface of the inner ring or outer ring should be 10 m or less, preferably 5 μm or less. Is preferred. It is preferable not to adhere the coating to the raceway surface. However, in order to simplify the work, the coating also adheres to the raceway surface depending on the coating formation method such as performing a coating formation process without masking. When the thickness of the coating adhering to the raceway surface exceeds 10 iz rn, the coating is peeled off by rolling of the rolling element, and the peeled coating is sunk into the rolling element as a foreign substance, and the bearing life is shortened.

[0029] In the present invention, the materials of the inner and outer rings of the rotating member and the bearing are not particularly limited as long as the above-described plating film can be formed, and members having a known material force can be used. The fixing roller is usually made of a lightweight aluminum alloy such as A5056 or A6063. Bearings are bearing steel (high carbon chrome bearing CilS G 4805), case hardened steel (JIS G 4104, etc.), high speed steel (AMS 6490), stainless steel (JIS G 4303), induction hardened steel (JIS G 4051). Etc.) etc. Other bearing alloys can also be used. In the present invention, since the above-mentioned coating is formed on at least one of the shaft portion of the rotating member and the bearing, the dynamic friction coefficient on the mating surface is obtained regardless of the combination of the material of the bearing and the rotating member. Can be small. [0030] Further, the type of grease to be sealed in a bearing such as a rolling bearing is not particularly limited as long as it is a grease generally used for a bearing. When the bearing itself requires conductivity, conductive grease containing a conductive agent such as carbon black, charged microgel particles, or graphite can be enclosed.

Example

Example 1 1 to Example 1 20 and Comparative Example 1 1 to Comparative Example 1 3

As an example and a comparative example, a coating was formed on the shaft portion of an aluminum rotating member, and a deep groove ball bearing was fitted to the shaft portion with a clearance fit (clearance 100 m) to produce a rotating member support structure for testing. . Table 1 shows the coating type, film thickness, etc. in each example and comparative example. The composition of the Ni-PTFE composite coating, Ni 82-86 wt ^_0/0, phosphorous 7-9 weight ^_0/0, PTF E (particle size not greater than 1 mu m) is 7-9% by weight.

[0032] In the test rotating member support structure, a test was performed in which the rotating member was rotated for 1000 hours, and the initial frictional coefficient (immediately after the start of operation) on the mating surface, the time of occurrence of abnormal noise, and the shaft and bearing The current-carrying performance was investigated. The test conditions and energization conditions are as follows. The results are shown in Table 1. In the investigation of energization performance, during the test time of 1000 hours, the energization performance was good when the resistance between the shaft and the bearing was maintained at 200 or less, and the resistance exceeding 200 degrees was regarded as poor. did.

[Test conditions]

• Bearing dimensions: 25 mm ID, 37 mm OD, 7 mm width

• Shaft temperature: 200 ° C

'Bearing load: 220 N (radial load)

• Rotation speed: 130 rpm

'Partner material: Aluminum

[Energization conditions]

• Charging voltage: 30 V

• Control resistance: 300 kQ (connected in parallel with the current measurement unit)

• Sampling interval: 1

[0033] Also, in Examples 1-2, 1-6, 1 10, 1-14 and 1-18, Comparative Examples 1 1 to 1 3 Then, the time-dependent change of the dynamic friction coefficient in the fitting surface on the same test conditions was measured. The results are shown in FIG. In Fig. 5, the horizontal axis represents the elapsed time (h), and the vertical axis represents the dynamic friction coefficient.

[0034] [Table 1]

[0035] As shown in Table 1, with the rotating member support structure on which the coating film of each example was formed, it was possible to prevent the generation of abnormal noise over a practically sufficient durability time (500 hours) in office equipment and the like. Furthermore, Examples 1 1 to 1-8 also had good energization performance. In addition, as shown in FIG. 5, in Examples 1-2, 1-6, 110, 1-14 and 1-18 where the thickness of the coating was 5 m, the dynamic friction coefficient could be kept low for a long time. Was able to prevent the generation of abnormal noise

[0036] Example 2-1 to Example 2-8 and Comparative Example 2-1 to Comparative Example 2-3

As examples and comparative examples, deep groove ball bearings having a coating formed on the inner diameter surface of the inner ring shown in FIG. 3 were prepared. Table 2 shows the coating type, film thickness, etc. in each example and comparative example. The Ni-PTFE composite coating was formed by electroless nickel plating, and the graphite coating was formed by sputtering. The composition of Ni-PTFE composite coating is 82-86 wt% Ni, 7-9 wt% phosphorus, PTFE (particle size 1 μm or less)? ~ 9% by weight. [0037] A test was conducted in which the inner ring of each of the deep groove ball bearings of each of the examples and the comparative examples was fitted to the shaft portion of the aluminum rotating member by a clearance fit (a clearance of 100 m), and the rotating member was rotated for 1000 hours. We investigated the initial dynamic friction coefficient (immediately after the start of operation), the time of occurrence of abnormal noise, and the current-carrying performance between the shaft and the bearing. The test conditions and energization conditions were the same as in Example 1 described above. The results are shown in Table 2. In the investigation of energization performance, during the test time of 1000 hours, the energization performance was good when the resistance between the shaft and the bearing was maintained at 200 or less, and the resistance exceeding 200 even once was regarded as defective. did.

[0038] Further, with respect to Example 2-2, Example 2-6, and Comparative Example 2-1 to Comparative Example 2-3, the change with time of the dynamic friction coefficient on the mating surface under the same test conditions was measured. The results are shown in Fig. 6. In Fig. 6, the horizontal axis represents elapsed time (h) and the vertical axis represents the dynamic friction coefficient.

[0039] [Table 2]

[0040] As shown in Table 2, the bearing with the coating film of each example is suitable for office equipment! For a practically sufficient durability time (500 hours), it was possible to prevent the generation of abnormal noise and to have good current-carrying performance. In addition, as shown in Fig. 6, in Example 22 and Example 2-6 where the film thickness is 5 μm, the dynamic friction coefficient can be kept low for a long time, preventing the generation of abnormal noise. did it.

[0041] Example 3-1 to Example 3-12 and Comparative Example 3-1 to Comparative Example 3-3

As examples and comparative examples, deep groove ball bearings having a coating formed on the inner diameter surface of the inner ring shown in FIG. 3 were prepared. Table 3 shows the coating type, film thickness, etc. in each example and comparative example.

[0042] A test was conducted in which the inner ring of each of the deep groove ball bearings of each of the examples and comparative examples was fitted to the shaft portion of the aluminum rotating member by a clearance fit (clearance: 100 m), and the rotating member was rotated for 1000 hours. The initial investigation of the mating surface (immediately after the start of operation) and the timing of abnormal noise were investigated. The test conditions were the same as in Example 1 described above. The results are shown in Table 3.

[0043] In addition, Example 3-2, Example 3-6, Example 3-10, and Comparative Example 3-1 to Comparative Example 3

Third, the mating under the same test conditions and the change with time of the dynamic friction coefficient on the surface were measured. The results are shown in FIG. In Fig. 7, the horizontal axis represents elapsed time (h) and the vertical axis represents the dynamic friction coefficient.

[0044] [Table 3]

[0045] As shown in Table 3, the bearings on which the coatings of the respective examples were formed were able to prevent the generation of abnormal noise over a practically sufficient durability time (500 hours) for office equipment and the like! . In addition, as shown in Fig. 7, in Examples 3-2, 3-6 and 3-10 where the film thickness was 5 m, the dynamic friction coefficient could be kept low for a long time, and abnormal noise was generated. We were able to prevent.

Industrial applicability

[0046] The rotating member support structure of the present invention can prevent abnormal noise such as squealing sound over a long period of time, and therefore can be suitably used for a fixing device for office equipment such as a copying machine or a printer.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view of a rotating member support structure of a fixing device using a deep groove ball bearing.

FIG. 2 is an enlarged view of a support structure portion in FIG. FIG. 3 is a sectional view of a deep groove ball bearing (rolling bearing).

[4] This is a diagram for explaining a mechanism for generating abnormal noise.

FIG. 5 is a diagram showing a change with time of a dynamic friction coefficient on a mating surface.

FIG. 6 is a diagram showing the change over time in the dynamic friction coefficient on the mating surface.

FIG. 7 is a graph showing a change with time of a dynamic friction coefficient on a mating surface. Explanation of symbols

1 Deep groove ball bearing (rolling bearing)

2 Inner ring

3 Outer ring

4 Rolling elements

5 Cage

6 Seal material

7 Grease

8 Coating

9 Fixing roller

9a Shaft

10 Heating heater

11 frames

Claims

The scope of the claims

[1] A rotating member support structure including a shaft portion of a rotating member in a fixing device and a bearing that is fitted to the shaft portion of the rotating member with a clearance fit and rotatably supports the shaft portion. At least one member of the shaft portion of the member and the bearing is formed with a coating having a low friction sliding property at least at a portion contacting the other member by fitting,

The rotating member support structure, wherein the coating film has a thickness of 2 to 10 / zm, and a coefficient of dynamic friction at a contact portion of the shaft portion of the bearing and the rotating member on which the coating film is formed is 0.2 or less.

[2] The rotating member support structure according to [1], wherein the coating is a non-conductive coating.

3. The rotating member support structure according to claim 2, wherein the coating is a polytetrafluoroethylene coating.

[4] The rotating member support structure according to [2], wherein the coating is a molybdenum disulfide molybdenum coating.

5. The rotating member support structure according to claim 2, wherein the coating film is a disulfurized tungsten coating.

6. The rotating member support structure according to claim 1, wherein the coating is a conductive coating.

7. The rotating member support structure according to claim 6, wherein the coating is a nickel-polytetrafluoroethylene composite coating.

8. The rotating member support structure according to claim 6, wherein the coating is a graphite coating.

[9] When the rotary member is rotated at 130 rpm for 500 hours while applying a radial load of 220 N to the bearing, the contact portion between the bearing on which the coating is formed and the shaft portion of the rotary member 2. The rotating member support structure according to claim 1, wherein the coefficient of dynamic friction is 0.2 or less.

[10] Fixing with a built-in heater for fixing the toner on the printing paper by the rotating member 2. The rotating member support structure according to claim 1, wherein the rotating member support structure is a roller.

A rolling bearing used in the rotating member support structure according to claim 1,

In the rolling bearing, a plurality of rolling elements are arranged between the raceway surfaces of the inner ring and the outer ring, and the rotating member of the fixing device is rotatably supported, and the shaft portion of the rotating member is the inner diameter surface of the inner ring or the inner ring. It is fitted to the outer diameter surface of the outer ring with a clearance fit,

A rolling bearing characterized in that the coating is formed on at least the inner diameter surface of the inner ring or the outer diameter surface of the outer ring where the shaft portion of the rotating member is fitted by clearance fitting.