JP2008019969A - Bearing for driving force transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a driving force transmission system in which false brinelling or rusting hardly occurs. <P>SOLUTION: The bearing 1 for the driving force transmission system comprises an outer ring 2, an inner ring 3, and a plurality of rollers 4 freely rotatably disposed between the track plane 2a of the outer ring 2 and the track plane 3a of the inner ring 3. At least one of the outer ring 2, the inner ring 3 and the rollers 4 is provided with a metal coating consisting of solid lubrication agent such as molybdenum disulfide, tin, copper system alloy, and zinc at least on part of the surface. The metal coating is formed by shot peening. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention supports a driving force transmission rotating member such as a driving force transmission gear support bearing and a free wheel hub bearing of a vehicle transmission, and is used in an environment where an outer ring and an inner ring rotate or stop integrally. The present invention relates to a driving force transmission bearing.

In general, the rotational output of an engine is transmitted to a wheel via a gear reduction mechanism such as a transmission or a transaxle. Many gears are built in these parts, and a number of reduction ratios can be obtained depending on the combination of gears.
Further, for example, in the driving force transmission gear support bearings in which the outer ring and the inner ring of the bearing are assembled in different structures, such as a bearing that is mounted in the shaft and supports the shaft that is inserted into the shaft, these inner rings In some cases, the outer ring is rotated in the same direction and at the same rotational speed, or the inner ring and the outer ring are both stopped. In this case, the outer ring and the inner ring do not rotate relative to each other, and a load and vibration are added to the bearing.

Further, in a freewheel hub bearing or the like to be mounted on the front wheel of a part-time four-wheel drive vehicle, unless the four-wheel drive operation is selected, relative vibration is only added.
JP-A-8-230509

By the way, as described above, when the inner ring and the outer ring rotate together without relative rotation, or when the inner ring and the outer ring are stopped, the inner ring and the outer ring operate integrally, and only the load and vibration are applied. It is well known that false brineling occurs in a bearing device that receives the bearing. When this false brinelling occurs, abnormal noise and vibration are generated in the bearing, and hard oxidized wear powder is generated, which may adversely affect the bearing life.
Accordingly, the present invention has been made paying attention to the above-mentioned conventional unsolved problems, and provides a driving force transmission system bearing capable of suppressing the occurrence of false brinelling and rust. It is aimed.

  In order to achieve the above object, a driving force transmission system bearing according to claim 1 of the present invention includes a first rotating member for driving force transmission and a driving force transmission rotatable coaxially with the first rotating member. And an inner ring, an outer ring, and a rolling element that is arranged to freely roll between the inner ring and the outer ring, and the inner ring and the outer ring rotate integrally with each other. In the driving force transmission system bearing used in a stopping environment, at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element is provided on at least a part of the surface thereof with a non-ferrous metal. A metal film formed by shot peening using a metal shot material is provided.

The driving force transmission system bearing according to claim 2 is characterized in that the shot material is a solid lubricant having a lubricating effect on the ferrous material.
The driving force transmission system bearing according to claim 3 is characterized in that the solid lubricant has a sacrificial anticorrosive effect on the ferrous material.
In the driving force transmission bearing according to a fourth aspect, the shot material is made of any one of molybdenum disulfide, tin, a copper alloy, and zinc.

The bearing for driving force transmission system according to claim 5 is a roller bearing, wherein the raceway surface or saddle surface of the inner ring, the raceway surface or saddle surface of the outer ring, and the rolling surface or head of the rolling element. At least one of the above is characterized in that the metal film is provided on at least a part of the surface thereof.
Furthermore, the bearing for driving force transmission system according to claim 6 is applied to a bearing for supporting a driving force transmission gear of a transmission of a vehicle.
A driving force transmission bearing according to a seventh aspect is applied to a bearing for a freewheel hub of a vehicle.

  In the first to seventh aspects of the invention, the first rotating member for transmitting driving force and the second rotating member for transmitting driving force that can rotate coaxially with the first rotating member. A driving force that is interposed between the inner ring and the outer ring, and a rolling element that is freely rollable between the inner ring and the outer ring, and that is used in an environment where the inner ring and the outer ring operate or stop together. In the transmission system bearing, a non-ferrous metal film is formed by shot peening on at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element. Therefore, the inner ring, the rolling element, and the outer ring As a result, the occurrence of false brinelling due to wear caused by minute slip between the rolling elements and the rolling elements is suppressed, and the occurrence of rust is suppressed by the non-ferrous metal film.

In particular, by using a solid lubricant having a lubricating effect on the ferrous material as the shot material, wear between the inner ring and the rolling element and between the outer ring and the rolling element is suppressed.
At this time, by using a solid lubricant having a sacrificial anticorrosive effect on the iron-based material, the metal film is preferentially melted even in an environment where rust is likely to occur, so that the rust preventive effect by the metal film can be obtained. It becomes possible.

According to the driving force transmission bearing according to the present invention, the metal film is formed by shot peening on at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element. It is possible to suppress the occurrence of false brinelling and the occurrence of rust due to wear associated with the minute slip between the moving body, outer ring and rolling element.
In particular, by using a solid lubricant having a lubricating effect on the iron-based material as the shot material, wear between the inner ring and the rolling element and between the outer ring and the rolling element can be suppressed.
At this time, by using a solid lubricant having a sacrificial anticorrosive effect on the iron-based material, the metal film is preferentially melted even in an environment where rust is likely to occur, so that the rust preventive effect by the metal film can be obtained. it can.

Embodiments of the present invention will be described below.
FIG. 1 shows a bearing for driving force transmission system according to the present invention, for example, a support bearing for supporting a driving force transmission gear in a gear reduction mechanism of a transmission as described in JP-A-2003-106407. In the free wheel hub structure described in Japanese Patent Application Laid-Open No. 8-230509, an intermediate is provided between the base end side of a cylindrical fixed gear having an external tooth screwed to the front end portion peripheral surface of the axle and the hub. A first driving force transmission shaft 21 that is rotatably supported, such as the inserted bearing J2, and the first driving force transmission shaft 21 inserted into the shaft of the first driving force transmission shaft 21. This is applied to the driving force transmission system bearing 1 interposed between the driving shaft 21 and the second driving force transmission shaft 22 rotating coaxially.

  As shown in FIG. 1, the driving force transmission system bearing 1 includes an outer ring 2 fitted to the inner periphery of one end of a first driving force transmission shaft (first rotating member) 21, and a second A plurality of rolls arranged between the inner ring 3 fitted to the outer periphery of the driving force transmission shaft (second rotating member) 22, the raceway surface 2 a of the outer ring 2, and the raceway surface 3 a of the inner ring 3. Rolling elements 4. At least one of the outer ring 2, the inner ring 3 and the rolling element 4 includes a non-ferrous metal film (not shown) on at least a part of its surface.

This metal film is formed by shot peening, and a solid lubricant having a lubricating effect on the iron-based material is applied as the shot material. Specifically, molybdenum disulfide, copper alloy, zinc, or the like can be applied.
The shot material shot peened to the construction target surface is melted by the frictional heat generated by the micro-slip between the shot material and the flange surface of the construction target surface when it collides with the construction surface. A film is formed on the construction surface. If a material having a melting point is used for the shot material, a film can be formed at any location.

The method of forming a film by shot peening does not need to be charged with hydrogen unlike plating, so there is no fear of delayed fracture. Rather, the effect of shot peening is formed on the surface to be worked, so that a compressive residual stress layer is formed on the surface, so that the fatigue life of the surface can be extended.
If the shot material is a material that is lubricious with respect to iron-based materials, such as molybdenum disulfide or tin, copper-based alloys, zinc, etc., friction between iron-based materials (friend-metal phenomenon) is prevented. Therefore, false bulletining can be reduced. Moreover, since a nonferrous metallic metal film is formed, generation | occurrence | production of rust can be suppressed.

In addition, when zinc is applied as a metal coating, zinc is a base metal than iron and has sacrificial anticorrosive properties, so that zinc preferentially dissolves even in an environment where rust is likely to occur. Further, it is possible to prevent the iron in the base material from being eluted and become rust, and to obtain the effect of preventing the wear powder from being oxidized.
Although aluminum may be used as a material having a sacrificial rust prevention effect, aluminum is not preferable for safety because of its relatively high flammability.

Further, when a roller bearing is used as the driving force transmission system bearing 1 and the main purpose is to improve the friction between the roller bearing surface and the head, the sacrificial corrosion resistance of the metal coating is more important. It becomes.
Also, shot material shot peened on the construction target surface is thick in the rough valleys on the construction target surface, and thinly adheres to the peaks, so the shot peened raceway surface, rolling surface, etc. Is smoother than the original state. Even when wear occurs, the shot material remains in the roughness valley, so that the smoothness is maintained for a long time.

The metal film does not need to be formed by a single shot peening.
For example, a multilayer metal film may be formed using different shot materials, and in this way, an effect that cannot be obtained with a single layer can be obtained. For example, the metal film has a two-layer structure, the surface layer is a film made of a metal that is nobler than iron, such as tin or nickel, and the inner layer on the base material side is a film made of a base metal rather than iron, such as zinc. If it is configured to prevent elution consumption due to sacrificial corrosion protection of base metals, it is possible to obtain a fretting suppression effect higher than that of a single layer.

Moreover, the surface layer is a film made of a hard metal such as nickel, cobalt, chromium, and the inner layer on the base material side is a film made of a sacrificial anticorrosive metal such as zinc, so that the surface hard layer prevents wear, It is possible to obtain an effect of role sharing by each layer such that the inner sacrificial anticorrosive layer prevents the wear powder from being oxidized.
Further, the composition of the metal film does not have to be a shot material made of a single non-ferrous metal.

  In other words, it is generally known that a zinc coating containing a small amount of nickel improves the corrosion resistance due to the catalytic effect of nickel. For example, a shot of peening is performed by adding a small amount of nickel shot material to the zinc shot material. When it does, the metal film which consists of nickel and zinc of nickel content a little higher than the mixing ratio of these shot materials will be formed. The reason why the nickel ratio of the metal film formed by shot peening is higher than the mixing ratio of the shot material is that nickel is easier to melt because of its large mass and poor thermal conductivity. By using nickel and zinc as a shot material with such a composition, it is possible to improve rust prevention performance while reducing the amount of expensive nickel used.

  Note that shot peening is unintentionally formed on a part of the raceway surface, for example, when shot peening is performed in a narrow place such as a cone roller bearing due to the characteristics of the processing method. Although there is a possibility that the film is formed, the portion where the film is formed has better lubricity, and a compressive residual stress layer is formed on the surface, which is rather preferable as a bearing. Therefore, it is not necessary to mask the track surface.

As described above, since the metal film is formed by shot peening on at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element of the driving force transmission system bearing 1, Generation | occurrence | production and generation | occurrence | production of rust can be suppressed.
In particular, when applied to a bearing for supporting a driving force transmission shaft in a gear transmission mechanism of a transmission, a free wheel hub, etc., as described above, the inner ring and the outer ring rotate integrally without relative rotation, In addition, there is a situation where both the outer ring and the outer ring remain stopped, and a relatively large load and vibration are applied, so there is a high possibility that false-brinering will occur, but as described above, the metal film is formed by shot peening. By forming, it is possible to easily reduce the occurrence of false bulleting, which is effective.

In particular, in the case of a roller bearing, it is possible to prevent the occurrence of false-brinering between the roller and the raceway surface, and to reduce the friction coefficient of the head portion, so that the raceway and rotational torque of the bearing are reduced. be able to. Therefore, the life of the bearing can be extended and the fuel efficiency of the vehicle can be improved.
In the above embodiment, the case where the present invention is applied to a bearing for supporting a drive force transmission shaft has been described. However, the present invention is not limited to this. Effective when applied to a bearing that is used in an environment where it operates integrally, such as when it is stopped, and where a relatively large force such as a driving force acts on the bearing and is likely to cause false brinelling or wear. It is.

It is sectional drawing which shows an example of the bearing for driving force transmission systems by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing for driving force transmission system 2 Outer ring 2a Raceway surface 3 Inner ring 3a Raceway surface 4 Rolling element 21 First driving force transmission shaft 22 Second driving force transmission shaft

Claims (7)

An inner ring, an outer ring, the inner ring, and the outer ring are interposed between a first rotating member for transmitting driving force and a second rotating member for transmitting driving force that can rotate coaxially with the first rotating member. A driving force transmission bearing used in an environment in which the inner ring and the outer ring rotate or stop together,
At least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element is formed on at least a part of the surface by shot peening using a shot material made of non-ferrous metal. A bearing for a driving force transmission system comprising a metal film.   The driving force transmission bearing according to claim 1, wherein the shot material is a solid lubricant having a lubricating effect on an iron-based material.   The bearing for driving force transmission system according to claim 2, wherein the solid lubricant has a sacrificial anticorrosive effect on the iron-based material.   4. The driving force transmission bearing according to claim 1, wherein the shot material is made of any one of molybdenum disulfide, tin, a copper-based alloy, and zinc. 5.   The driving force transmission bearing is a roller bearing, and is at least one of a raceway surface or saddle surface of the inner ring, a raceway surface or saddle surface of the outer ring, and a rolling surface or head of the rolling element. 5. The driving force transmission system bearing according to claim 1, wherein the metal coating is provided on at least a part of the surface of the bearing.   The bearing for a driving force transmission system according to any one of claims 1 to 5, which is applied to a bearing for supporting a driving force transmission gear of a transmission of a vehicle.   6. The driving force transmission system bearing according to claim 1, which is applied to a bearing for a free wheel hub of a vehicle.

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