WO2006120984A1

WO2006120984A1 - Bearing and rotating shaft support structure

Info

Publication number: WO2006120984A1
Application number: PCT/JP2006/309179
Authority: WO
Inventors: Ryouichi Nakajima; Kenichiro Naito; Hideaki Tanaka; Ryuusuke Katsumata
Original assignee: Ntn Corporation
Priority date: 2005-05-10
Filing date: 2006-05-02
Publication date: 2006-11-16
Also published as: JP2006316824A

Abstract

A bearing and a rotating shaft support structure, wherein the film of a solid lubricant (17) is formed on the inner diameter surface (15) of an inner ring supporting a shaft (21) and the width faces (16) of the inner ring (11) which are the end face thereof crossing perpendicular to the inner diameter surface (15). When the shaft (21) is rotated, the outer peripheral surface (22) of the shaft (21) is brought into slidable contact with the inner diameter surface (15) of the inner ring (11) and the width face (16) of the inner ring (11) is brought into slidable contact with the side surface part (24) of a retainer ring (23). However, since the film of the solid lubricant (17) is formed on the surfaces of the inner diameter surface (15) and the width faces (16), lubricities between the outer peripheral surface (22) of the shaft (21) and the inner diameter surface (15) of the inner ring (11) and between the width face (16) of the inner ring (11) and the side surface part (24) of the retainer ring (23) are increased to reduce friction. Thus, noise can be prevented from occurring.

Description

Specification

Bearing and rotary shaft support structure

Technical field

The present invention relates to a bearing and a rotary shaft support structure, and more particularly to a bearing and a rotary shaft support structure in which a shaft and a bearing inner ring are used as a gap.

Background art

A fixing unit of a copying machine or LBP (Laser Beam Printer) is heated to a high temperature of about 200 ° C. in order to fix the toner on a sheet. In such high temperature environments, for bearings used as rollers in the fixing section, heat resistant fluorine grease can be enclosed inside the rolling bearings, or a heat insulating sleeve that can keep the bearing temperature low, etc. Various devices have been made!

[0003] In addition, with regard to bearings that are used as the shaft rotates, generally, the shaft and the bearing inner ring are used in a close fit, but for bearings used in copying machines and rollers of the fixing portion of LBP, etc. First, the shaft and the bearing inner ring are used with a gap fit in order to improve maintainability.

[0004] In the case of a bearing in which a shaft and a bearing inner ring are used in a clearance fit, abnormal noise may occur when the shaft rotates. This is because there is a gap between the shaft and the bearing inner ring, which causes creeping and friction when the shaft rotates.

A rolling bearing 1S in which the dimensional accuracy of the bearing inner ring is improved in order to prevent the generation of such abnormal noise is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-303329.

According to Japanese Patent Application Laid-Open No. 2002-303329, dimensional accuracy is improved by finishing the outer shape of the inner ring, which is a component member of the rolling bearing, by impact polishing such as barrel polishing, etc., and friction during rotation of the shaft. Reduce noise and reduce the generation of abnormal noise! /.

Even if the dimensional accuracy of the rolling bearing is improved as in Japanese Patent Application Laid-Open No. 2002-303329, when there is a gap between the shaft and the bearing inner ring, the shaft and the inner ring are still Noise caused by friction between In such a case, for example, a liquid lubricant such as fluorine grease is applied between the shaft and the bearing inner ring to improve the lubricity, reduce the friction between the shaft and the bearing inner ring, and noise is generated. May be suppressed. However, in the case of a liquid lubricant, when the shaft rotates, there is a risk that the peripheral portion of the bearing oozes and an abnormal noise occurs. In addition, when used for a certain period of time, the liquid lubricant may die and abnormal noise may start to be generated again. In particular, in the above-mentioned high temperature environment, abnormal noise occurs in a short time.

Disclosure of the invention

The present invention relates to a bearing and a rotary shaft support structure capable of preventing generation of abnormal noise when the shaft rotates over a long period of time in a bearing in which the shaft and the bearing inner ring are used for gap fitting. Intended to be provided.

A rolling bearing according to the present invention is a bearing having an inner ring and an outer ring, and a coating of a solid lubricant is formed on the inner diameter surface and the end surface of the inner ring.

Preferably, the solid lubricant includes one or more compounds selected from the group consisting of molybdenum disulfide, tungsten disulfide, and PTFE (Poly Tetra Fluoro Ethylene).

The thickness of the solid lubricant film may be 3 μm or more, preferably 5 μm or more.

[0013] More preferably, the thickness of the solid lubricant coating is 5 :: LO / z m.

Note that the bearing may be a rolling bearing.

In another aspect of the present invention, the rotary shaft support structure includes a rotary shaft and a bearing having an inner ring and an outer ring supporting the rotary shaft with a gap fit, and a solid lubricant is applied to the inner diameter surface and the end surface of the inner ring. Is formed.

Preferably, the rotation shaft includes a positioning member that abuts on the end face of the inner ring via the coating of the solid lubricant.

According to the present invention, the lubricity of the shaft and the bearing inner ring can be improved during rotation of the shaft by the coating of the solid lubricant formed on the inner diameter surface and the end surface of the inner ring. Also, since it is a solid lubricant, it does not bleed to the periphery of the bearing and die.

[0018] As a result, in a bearing in which the shaft and the bearing inner ring are used for gap fitting, it is possible to provide a bearing capable of preventing generation of abnormal noise when the shaft rotates for a long time. In addition, by using the rotary shaft and the above-described bearing in a clearance fit, it is possible to provide a rotary shaft support structure capable of preventing generation of noise over a long period of time. Brief description of the drawings

FIG. 1 is an enlarged view of a part of a cross section of a rolling bearing according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a part of a rotary shaft support structure in which a shaft is supported on the inner ring of a rolling bearing.

FIG. 3 is a schematic view of a test apparatus for measuring the effect of abnormal noise generation.

FIG. 4 is an enlarged view of a part of the cross section of the rolling bearing when a solid lubricant is formed on a part of the width surface of the inner ring.

FIG. 5 is a cross-sectional view showing a part of the rotary shaft support structure in which the shaft is supported on the inner ring of the rolling bearing when the solid lubricant is formed on a part of the width surface of the inner ring.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged view of a part of a cross section of a rolling bearing in a case where a bearing used as a gap fit between a shaft and an inner ring according to an embodiment of the present invention is a rolling bearing. Referring to FIG. 1, a rolling bearing 10 includes an inner ring 11, an outer ring 12, a cage 13, and balls 14 as rolling elements. The ball 14 is held between the inner ring 11 and the outer ring 12 by a cage 13. A coating of a solid lubricant 17 described later as a lubricant is formed on the inner diameter surface 15 of the inner ring 11 supporting the shaft and the width surfaces 16a and 16b on both sides of the inner ring 11 which is an end surface orthogonal to the inner diameter surface 15 . Here, the film refers to a layer of film thickness of several / zm force / tens of tens / zm, and is very thin compared to the dimensions of each part of the rolling bearing. There is no impact. In addition, in FIG. 1, FIG. 2, FIG. 4, and FIG. 5, the layer of the film of a solid lubricant is expressed thickly compared with other dimensions for the ease of description.

Next, a method of forming a solid lubricant coating on the inner diameter surface and the width surface of the inner ring will be described. The solid lubricant used may be a solid lubricant containing one or more compounds selected from the group consisting of molybdenum disulfide, tungsten disulfide and PTFE. The method for forming the coating is not particularly limited as long as the coating can be formed on the inner diameter surface and the width surface of the inner ring of the rolling bearing by the sputtering method (vapor deposition method), debiting method (immersion method) or the like. . Coating thickness and uniformity are sputtering The degree of vacuum is adjusted according to the degree of vacuum, the deposition time, the amount of the solid lubricant used, etc., and the degree of immersion 1 is adjusted according to the immersion time, the concentration of the immersion liquid, etc.

FIG. 2 is a cross-sectional view showing a part of a rotary shaft support structure in which a shaft is supported on the inner ring of the rolling bearing shown in FIG. Referring to FIG. 2, the rotary shaft support structure 20 supports the shaft 21 on the inner ring 11 of the rolling bearing 10 with a gap fit. Further, the rotary shaft support structure 20 axially fixes the shaft 21 to the rolling bearing 10 by means of a snap ring 23 as a positioning member for positioning the shaft in the axial direction. When the shaft 21 rotates, the outer circumferential surface 22 of the shaft 21 and the inner diameter surface 15 of the inner ring 11 slide, and the width surface 16a of the inner ring 11 slides on the side surface 24 of the retaining ring 23. However, since the coating of the solid lubricant 17 is formed on the inner diameter surface 15 and the width surface 16 a, the outer peripheral surface 22 of the shaft 21 and the inner diameter surface 15 of the inner ring 11, and the width surface 16 a of the inner ring 11 and the side surface portion of the retaining ring 23 The lubricity with 24 is improved, the friction is reduced, and the generation of noise is prevented.

By forming a coating of the solid lubricant 17 on the end faces 16a and 16b on both sides of the inner ring 11, the axial directionality of the inner ring 11 does not occur. It becomes easy.

Further, the above-mentioned solid lubricant is chemically stable and can not be easily melted or decomposed, for example, in a high temperature environment of about 200 ° C. It does not bleed out around the bearing and die.

A stepped shaft having a thin portion, a large portion and a thin portion, and the step portion as the positioning member and the width surface of the inner ring are in contact with each other through the coating of the solid lubricant, similarly. The abrasion is reduced and the generation of noise is prevented.

For the rolling bearing shown in FIG. 1, a test was conducted to confirm the presence or absence of abnormal noise when the type of solid lubricant and the thickness of the film were changed. Fig. 3 is a schematic view of the test equipment for checking the occurrence of abnormal noise. Referring to FIG. 3, the test apparatus 30 includes a bearing holding portion 31 for holding the rolling bearings 10a and 10b, and a shaft support portion including a drive portion 32 for rotating the shaft 21 supported by the rolling bearings 10a and 10b. And a load application unit 34 having a compression panel 33 for applying a load to the bearing holder 31. The radial load of 220 N is applied to the rolling bearings 10 a and 10 b and the shaft 21 by the compression panel 33. The shaft 21 is rotated by the drive unit 32 at a rotational speed of 130 rpm. In addition, the heater 21 attached to the shaft 21 and the bearing holder 31 Is heated to 200 ° C. The power required for the heater 35 is also supplied by the external force of the test apparatus 30 by means of a slip ring 36 mounted at one end of the shaft 21.

The test conditions are as follows. The test results are shown in Table 1.

Test bearing: 6805 (inner ring inner diameter φ 25 π ι π ι outer ring diameter φ 37 π 37 π Χ width 7 mm) shaft temperature [° C.]: 200

Radial load [N]: 220

Rotation speed [rpm]: 130

Shaft material: STKM11

Examination time [hour]: 1000

Judgment method: By hearing

[Table 1]

[0030] Table 1 is a table showing the results of tests in which the presence or absence of abnormal noise was confirmed by the test apparatus 30 shown in FIG. 3 when the type of solid lubricant and the thickness of the film were changed. Referring to Table 1, in the case where the film of the solid lubricant was not formed, abnormal noise was generated after 8 hours, whereas in the case where the film of molybdenum disulfide or PTFE was formed 3 / z m, the 500 hours was elapsed. The noise did not occur until the end of the day. Further, when a coating of molybdenum disulfide or PTFE was formed to a thickness of 10 m, abnormal noise did not occur even after 1000 hours.

Therefore, when using molybdenum disulfide or PTFE as a solid lubricant, the thickness of the solid lubricant coating is preferably at least 5 μm or more.

Further, in the case of forming a coating of 3 μm of tungsten disulfide, no noise was generated even after 1000 hours had passed. Therefore, in the case of using tungsten disulfide as a solid lubricant, the thickness of the coating of the solid lubricant should be 3 μm or more.

When using any solid lubricant, it is preferable to use a solid lubricant in order to minimize the amount of solid lubricant used without deteriorating the inner diameter dimensional accuracy of the inner ring more than necessary. The thickness of the coating is preferably 5 to 10 m.

Next, another embodiment of the present invention will be described. In the above embodiment, the force using the solid lubricant film formed on the entire inner diameter surface and the width surface of the inner ring is not limited thereto. You may use what the film of the agent formed. FIG. 4 is an enlarged view of a part of the cross section of the rolling bearing in this case. Referring to FIG. 4, a solid lubricant film is formed on the entire inner diameter surface 15 of the inner ring 11 and a part of the width surfaces 16a and 16b. Here, the coating of the solid lubricant 17 is formed concentrically at a constant distance from the inner diameter surface 15 side, and is continuous in the circumferential direction. The method of forming the coating of the solid lubricant 17 is the same as that described above.

FIG. 5 is a cross-sectional view showing a part of a rotary shaft support structure in which a shaft is supported on the inner ring of the rolling bearing shown in FIG. Referring to FIG. 5, the rotary shaft support structure 20 supports the shaft 21 on the inner ring 11 of the rolling bearing 10 with a gap fit. When the shaft 21 rotates, the outer peripheral surface 22 of the shaft 21 and the inner surface 15 of the inner ring 11 slide, and the width surface 16a of the inner ring and the side portion 24 of the retaining ring 23 slide, but the inner surface 15 and the width surface 16a Since a coating of solid lubricant 17 is formed on a part of the surface, the lubricity between the outer surface 22 of shaft 21 and the inner diameter surface 15 of inner ring 11 and the width surface 16a of inner ring and side surface 24 of retaining ring 23 is improved Friction is reduced and noise is prevented.

In FIG. 1, FIG. 2, FIG. 4 and FIG. 5, a film is formed of a continuous layer of solid lubricant 17 on inner diameter surface 15 and width surfaces 16a and 16b for the width surface and part of the width surface. The coating of the solid lubricant 17 formed on the inner diameter surface 15 and the width surfaces 16a and 16b, which illustrates the inner ring, may not be formed continuously. In particular, the connection between the inner diameter surface 15 and the width surfaces 16a and 16b is usually chamfered, and this portion does not slide with the shaft 21 and the side surface 24 of the retaining ring 23, so solid lubrication Coating of agent 17 is unnecessary.

Also, in the above embodiment, the coating of the solid lubricant is applied to the width surfaces of both sides of the inner ring. However, the invention is not limited to this, and the coating of the solid lubricant may be formed only on the width surface of the side that slides with the positioning member such as the retaining ring. By using such a configuration, the amount of solid lubricant used can be reduced. In this case, it is preferable to colorize the film of the solid lubricant to be formed so that the direction of attachment of the inner ring is not mistaken at the time of assembly and maintenance.

In addition, as for the method of forming a solid lubricant film on the inner diameter surface and the width surface, after masking the portion other than the inner diameter surface and the width surface of the inner ring, the entire inner ring is sputtered or dived, and then the masking is removed By forming a film on the inner diameter surface and the width surface, and forming a solid lubricant coating on the entire inner ring by sputtering or dicing, and then forming a solid on the portion other than the inner diameter surface and the width surface The lubricant film may be removed by shot blasting or the like.

The types of solid lubricants shown in Table 1 above are the experimental results for molybdenum disulfide, molybdenum disulfide, and a compound that also has only PTFE force. Molybdenum molybdenum, tungsten disulfide, PTFE force Grouping force One or more compounds selected may be used as a solid lubricant. In addition, other industrial solid lubricants, for example, layered solid lubricants such as boron nitride and graphite, and a group force also serving as a solid lubricant of plastics such as polyimide, nylon, polyester, etc. One or more compounds selected As well. By doing this, it is possible to select a more optimal solid lubricant in consideration of the environment in which the bearing is used and other conditions.

As described above, the force for which the embodiment of the present invention has been described with reference to the drawings. The present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same or equivalent scope of the present invention.

Industrial applicability

The bearing according to the present invention can prevent generation of abnormal noise for a long time by forming a coating of a solid lubricant on the inner diameter surface and the width surface of the inner ring, and therefore the fixing portion of a copying machine or LBP, etc. It is effectively used by

Claims

The scope of the claims

A bearing having an inner ring and an outer ring,

A bearing, wherein a coating of a solid lubricant is formed on an inner diameter surface and an end surface of the inner ring. The bearing according to claim 1, wherein the solid lubricant comprises one or more compounds selected from molybdenum disulfide, tungsten disulfide, and PTFE force groups.

The bearing according to claim 1, wherein the thickness of the solid lubricant coating is 3 μm or more.

The bearing according to claim 1, wherein the thickness of the solid lubricant coating is 5 μm or more.

The bearing according to claim 1, wherein the thickness of the solid lubricant coating is 5 to: LO m.

The bearing according to claim 1, wherein the bearing is a rolling bearing.

With the rotation axis,

A rotary shaft support structure, comprising: a bearing having an inner ring and an outer ring that supports the rotary shaft with a gap fit; and a coating of a solid lubricant is formed on an inner diameter surface and an end surface of the inner ring.

The rotary shaft support structure according to claim 7, wherein the rotary shaft includes a positioning member that abuts on an end surface of the inner ring via the coating of the solid lubricant.