JP4743033B2 - Bearing for center bearing - Google Patents

Description

  The present invention relates to a bearing for a center bearing that rotatably supports an intermediate portion of a propeller shaft of a vehicle.

An intermediate portion of the propeller shaft of the vehicle is supported by the vehicle body via a center bearing. That is, the center bearing is used in an environment in which muddy water from the road surface may splash. In particular, in regions where snow falls, the bearings are exposed to a severe corrosive environment due to the effect of a snow melting agent.
In order to avoid this, a number of measures have been taken, such as providing an externally mounted oil seal and labyrinth for the center bearing unit, and making it difficult for water and dust to enter inside the bearing ( For example, see Patent Document 1).
JP 2006-62621 A

However, although various measures have been taken as described above, when a large amount of water is present around the bearing, there is a possibility that water or the like may enter the bearing. Further, when rust or flaking or the like occurs on the rolling element, there is a possibility that it may lead to the generation of abnormal noise or the like, and therefore further measures have been desired.
Therefore, the present invention has been made paying attention to the above-mentioned conventional unsolved problems, and an object thereof is to provide a bearing for a center bearing capable of suppressing the occurrence of rust, flaking and the like.

In order to achieve the above object, a bearing for a center bearing according to claim 1 of the present invention is a bearing for a center bearing that rotatably supports a propeller shaft of a vehicle on a vehicle body at an intermediate portion thereof, an inner ring, an outer ring, A rolling element that is freely rollable between the inner ring and the outer ring, and 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 a surface thereof. At least a part thereof includes a metal film formed by multiple shot peening processes using different non-ferrous metal shot materials, and the metal film is made of a metal having sacrificial anticorrosive properties with respect to ferrous materials. Sacrificial anticorrosive film formed on the base material side by shot peening using shot material and surface by shot peening using hard metal shot material It is characterized in that a two-layer structure composed of the formed hard coating.

A center bearing for a bearing according to claim 2 is a center bearing for supporting a propeller shaft of a vehicle on a vehicle body rotatably at an intermediate portion thereof, and is rotated between an inner ring, an outer ring, the inner ring and the outer ring. And at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element is different from each other on at least a part of the surface thereof. It has a metal film formed by multiple shot peening processes using a metal shot material, and the metal film is formed on the base material side by shot peening process using a shot material of a base metal rather than iron. A two-layer structure consisting of a sacrificial anticorrosive film and a film formed on the surface by shot peening using a shot material made of a metal nobler than iron It is characterized.

According to the first or second aspect of the invention, in the bearing for the center bearing that rotatably supports the propeller shaft on the vehicle body, at least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element. First, since a non-ferrous metal film is formed by shot peening, the occurrence of rust and flaking is suppressed.
In particular , by forming a metal film having a laminated structure of a sacrificial anticorrosive film formed on the base material side and a hard film formed on the surface, oxidation of the bearing is prevented by the sacrificial anticorrosive film, and the hard film Wear and the like are prevented.
Also, for example, a laminate of a film formed on the surface using a shot material made of a metal nobler than iron and a sacrificial anticorrosive film formed on the base material side using a shot material made of a metal lower than iron By forming a metal film having a structure, a higher rust prevention effect can be obtained than in the case of a single layer.

According to the bearing for the center bearing according to the present invention, since a 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, generation of rust. And flaking can be suppressed.
In particular, by using a metal film having a laminated structure of the sacrificial牲防corrosion-resistant coating and a hard coating, it is possible to suppress the occurrence of abrasion or the like thereby preventing the oxidation of the bearing.
Furthermore, for example, a laminate of a film formed on the surface using a shot material made of a metal nobler than iron and a sacrificial anticorrosive film formed on the base material side using a shot material made of a metal lower than iron By forming a metal film having a structure, a higher rust prevention effect can be obtained than in the case of a single layer.

Embodiments of the present invention will be described below.
FIG. 1 is a partial sectional view showing a structure around a center bearing according to the present invention.
As shown in FIG. 1, a propeller shaft 22 that links a vehicle transmission and a differential gear to transmit a driving force of an engine to wheels is arranged at a lower portion of a vehicle body 21, and the propeller shaft 22 is a support device. 23 is supported by the vehicle body 21.
The support device 23 includes a center bearing 1 formed of a single row ball bearing, a bearing support 2 that holds the center bearing 1, and a bracket 3 that supports the bearing support 2 on the vehicle body 21. The coupling between the bearing support 2 and the bracket 3 and the coupling between the bracket 3 and the vehicle body 21 are performed via bolts (not shown).

  The bearing support 2 includes an insulator 2a obtained by molding a flexible material such as rubber in an annular shape, a retainer ring 2b outside the insulator 2a, and a housing 2c inside the insulator 2a. The insulator 2a has a substantially U-shaped cross section when the insulator 2a is cut in the radial direction in order to improve the vibration-proof property in shape, and the insulator 2a and the retainer ring 2b are formed as shown in FIG. And the housing 2c is joined by vulcanization adhesion.

  As shown in FIG. 1, the center bearing 1 includes an inner ring 11 fitted to an intermediate portion of the propeller shaft 22, an outer ring 12 press-fitted into the inner periphery of the housing 2 c of the bearing support 2, and a track of the inner ring 11. A plurality of rolling elements 13 are provided between the surface 11a and the raceway surface 12a of the outer ring 12 so as to be freely rollable. At least one of the inner ring 11, the outer ring 12, and the rolling element 13 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 material having a rust prevention effect on the iron-based material is applied as the shot material. Specifically, tin, a copper-based alloy, zinc, or the like can be applied, and a thermoplastic resin such as polypropylene, polyethylene, or vinyl chloride can be applied.
The shot material shot peened into the center bearing 1 such as the raceway surface and the rolling element is frictional heat caused by micro-slip between the shot material and the flange surface of the construction target surface when colliding with the construction surface. As a result, the surface of the shot material is melted and adheres to the work surface to form a film. 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 worry of delayed fracture. Rather, the effect of shot peening on the surface to be worked forms a compressive residual stress layer on the surface, so that the fatigue life of the surface can be extended.
As the shot material, if a material having an antirust effect on the iron-based material, such as tin, a copper-based alloy, zinc, or the like, is applied, it is possible to prevent friction between the iron-based materials (friend-metal phenomenon). Therefore, the generation of rust can be suppressed and the occurrence of flaking and the like can be reduced.

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.
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 hard metal such as nickel, cobalt, or chromium, and the inner layer on the base material side is a film made of a sacrificial anticorrosive metal such as zinc. The effect by the division of roles by each layer such that the hard layer prevents wear and the inner sacrificial anticorrosive layer prevents the wear powder from being oxidized can be obtained.
In addition, by making the surface layer a film made of a metal that is nobler than iron, such as tin or nickel, and making the inner layer on the base material side a film made of a metal that is baser than iron such as zinc, the sacrificial corrosion protection of the base metal If it comprises so that elution consumption may be prevented, the higher rust prevention effect can be acquired rather than the case of a single layer.

  Thus, since the metal film is formed by shot peening on at least one of the raceway surface 11a of the inner ring 11 of the center bearing 1, the raceway surface 12a of the outer ring 12, and the rolling elements 13, Generation | occurrence | production of flaking etc. can be suppressed. In particular, in the case of the center bearing 1, as described above, since it is used in an environment where rust and foreign matter are relatively easily mixed, there is a relatively high possibility that rust and flaking will occur. By forming a metal film by shot peening, the occurrence of rust and flaking can be easily reduced, which is effective. In addition, as described above, the center bearing 1 is provided with an externally mounted oil seal or has a structure in which water and dust are difficult to enter, and a metal film is formed as described above, so that rust generation and flame are more reliably generated. Generation of king and the like can be suppressed. In addition, even when the externally mounted oil seal or the structure is difficult for water and dust to enter, in some cases, water or dust may enter due to deterioration over time, but if water or dust enters. Even if it exists, generation | occurrence | production of rust, flaking, etc. can be suppressed as mentioned above. Therefore, it is possible to prevent water and dust from entering by forming an oil seal and a structure in which water and dust are difficult to enter, and further forming a metal film by shot peening as described above. Even if dust enters, it is possible to avoid the occurrence of rust and flaking, and the life of the center bearing 1 can be extended accordingly.

It is a figure which shows the structure of a center bearing and its periphery to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Center bearing 2 Bearing support 3 Bracket 11 Inner ring 11a Raceway surface 12 Outer ring 12a Raceway surface 13 Rolling element 21 Car body 22 Propeller shaft

Claims (2)

In the bearing for the center bearing that supports the propeller shaft of the vehicle to the vehicle body rotatably in its middle part,
An inner ring, an outer ring, and a rolling element that is arranged to roll between the inner ring and the outer ring,
At least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element is shot peening a plurality of times using different non-ferrous metal shot materials on at least a part of the surface thereof. With a metal film formed by processing,
The metal film is a sacrificial anticorrosive film formed on the base material side by shot peening using a metal shot material having a sacrificial anticorrosive property to an iron-based material,
A bearing for a center bearing having a two-layer structure comprising a hard coating formed on a surface by shot peening using a hard metal shot material . In the bearing for the center bearing that supports the propeller shaft of the vehicle to the vehicle body rotatably in its middle part,
An inner ring, an outer ring, and a rolling element that is arranged to roll between the inner ring and the outer ring,
At least one of the raceway surface of the inner ring, the raceway surface of the outer ring, and the rolling element is shot peening a plurality of times using different non-ferrous metal shot materials on at least a part of the surface thereof. With a metal film formed by processing,
The metal film is a sacrificial anticorrosive film formed on the base material side by shot peening using a shot material of a base metal rather than iron,
A bearing for a center bearing having a two-layer structure comprising a coating formed on a surface by shot peening using a shot material made of a metal nobler than iron .

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