JP2001208079A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing having such a specification identification which exerts no influence with regard to bearing dimension or mechanical strength, is stable in handling, has no adverse effect on environmental load, is suitable for mass production, and is inexpensive in production cost. SOLUTION: Of the bearing component parts, one of the component parts, which have been finish machined after hardening treatment including quenching and tempering, being further received a heat treatment under a predetermined temperature lower than the tempering temperature after the finish machining, is added with a coloring for specification identification to the surface of the bearing component part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing composed of bearing components including a metal race and a rolling element, and more particularly, to the identification of specifications thereof.

[0002]

2. Description of the Related Art In the case of a plurality of rolling bearings having the same appearance even if the type of encapsulated grease and other specifications are different, the specifications cannot be identified. Therefore, when assembling a plurality of such rolling bearings to the device, it is desirable to attach an identification sign indicating that the specifications are different from those of other rolling bearings in order to improve the assembling workability.

[0003] Conventional rolling bearings are those in which specifications are identified by engraving symbols or characters on the specifications of the raceway surface, those which are identified by the presence or absence of copper plating, or those in which the raceway surface is black. Dyeing and specification identification are available.

[0004]

However, in the case of the rolling bearing provided with the specification identification by the above-described engraving, if the rolling bearing is further miniaturized, it becomes difficult to distinguish the engraving form of the raceway surface, and the assembling workability is reduced. Not much improved.

[0005] In the case of a rolling bearing provided with specification discrimination by copper plating, plating is easily peeled off depending on handling, and stable specification discrimination cannot be achieved.

[0006] Further, in the case of a rolling bearing provided with specification discrimination based on blackening of the raceway surface, the blackening component often causes an environmental load depending on the usage environment of the rolling bearing, and is not always preferable.

[0007] Furthermore, the above specification identification form is a structure that is completely unsuitable for mass production of rolling bearings because it is a completely separate specification identification forming step from the general manufacturing process of rolling bearings. It requires a device and has an extra high manufacturing cost.

Accordingly, the present invention is provided with specification identification that does not affect bearing dimensions or bearing strength, is stable in handling, has no influence on environmental load, is suitable for mass production, and requires low production cost. It is intended to provide a rolling bearing.

[0009]

A first rolling bearing according to the present invention is any one of bearing components which have been subjected to a hardening process including quenching and tempering and then to a finishing process. The component is subjected to a heat treatment at a desired temperature lower than the tempering temperature after the finishing processing, so that the surface of the bearing component is colored for specification identification.

Here, the bearing component to be subjected to the heat treatment includes a single or multiple races, a single or multiple rolling elements, or a combination of races and rolling elements. This includes all, a plurality, or a combination of all of the other bearing components that make up.

The specification means not only one of the types of the filled grease and the lubricant, the shape of the bearing ring, the rolling element, the shape of the retainer, etc., but also indicates a plurality of specifications. Including. In addition, the contents of the specifications are not limited to those described in this specification, but include all specifications related to the bearing.

According to the first aspect of the present invention, the color development at the heat treatment at a desired temperature lower than the tempering temperature after the hardening treatment is regarded as specification identification. Therefore, unlike the conventional specification identification by engraving, A bearing that can accurately recognize its specification even if the bearing is downsized, makes it easier to distinguish it from other bearings with the same appearance in terms of specifications, and improves the above-described assembly workability. Becomes

According to the first aspect of the present invention, since the color is formed by heat treatment at a desired temperature lower than the tempering temperature after the hardening treatment, the thickness of the oxide film due to the color formation becomes thin, and the bearing dimensions and bearing strength are reduced. The bearing is not affected.

Further, according to the first aspect of the present invention, unlike the copper plating, the bearing is stable in handling and is not provided with specification discrimination that causes an environmental load on the operating environment of the bearing. Is a preferred bearing.

In particular, in the first case of the present invention, the specification identification is formed by simply lowering the tempering temperature in the same process as the hardening process which is a general manufacturing process of the bearing. The bearing structure is suitable for mass production, and a special specification identification forming device is not required, and the manufacturing cost is low.

As a first preferred embodiment of the present invention, two bearing rings that are rotatable relative to each other are provided as the bearing components, and at least one of the bearing rings is colored for specification identification. In such a case, one or the other of the two bearing rings, or both, or a combination of no coloring, becomes a bearing that enables identification of a plurality of types of specifications, and is more preferable.

As a first preferred embodiment of the present invention, the coloring is selectively applied to at least an outer peripheral surface or an end surface of the race. In such a case, since the outer peripheral surface and the end surface are selectively colored, it is more preferable that the selected coloring enables specification of more types of bearings having different specifications to be distinguished.

According to the second rolling bearing of the present invention, a hardening process is performed on a bearing component which has been subjected to a hardening process of quenching the bearing component in an oxygen-free atmosphere and then tempering in air. The layer colored at the time of return is removed for specification identification.

According to the second aspect of the present invention, the color identification layer appearing by tempering in the air is removed and the specification identification is performed. Therefore, unlike the conventional specification specification by engraving,
A bearing that can accurately recognize its specification even if the bearing is downsized, makes it easier to distinguish it from other bearings with the same appearance in terms of specifications, and improves the above-described assembly workability. Becomes

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. In the embodiment of the present invention, the rolling bearing is described as being applied to a thrust needle roller bearing. However, the present invention may be similarly applied to other rolling bearings such as a needle roller bearing with a cage.

FIG. 1 is a longitudinal sectional view showing an upper half of a thrust needle roller bearing according to an embodiment of the present invention, FIG. 2 is a perspective view of a race of the bearing of FIG. 1, and FIG. Longitudinal cross-sectional view from the front of a masking device for performing a color forming process,
FIG. 4 is a partially cutaway front view of another masking device for performing a color developing process on a race.

First, referring to FIG. 1, the thrust needle roller bearing (hereinafter simply referred to as a bearing) of the embodiment includes a pair of races 1 and 2, a plurality of needle rollers 3, and a retainer 4. The bearing components constituting these bearings are subjected to hardening treatment including quenching and tempering.

The two races 1 and 2 are axially opposed to each other as races, and one of the races 1 has an outer circumferential flange 1b at the outer circumferential end of an annular plate 1a. The other race 2 is provided with the other inner circumferential flange 2b in the axial direction at the inner circumferential end of the annular plate 2a.

The retainer 4 is formed by connecting two metal plates 4a and 4b from the axial direction, and the needle rollers 3 are held in a pocket 4c thereof in a non-separable manner.

In this bearing, the plurality of needle rollers 3 held in the pockets 4c of the cage 4 in the radial annular spaces of the flanges 1b and 2b of the races 1 and 2 are provided.
Is interposed.

The bearing of the embodiment having the above-mentioned configuration is characterized in that, of these bearing components including the races 1, 2 and the needle rollers 3, the finishing process is performed after the hardening process is performed. For any of the bearing components
After the finish processing, for example, by performing a heat treatment at a desired temperature lower than the tempering temperature on one of the races 1, the surface of the race 1 is subjected to a coloring process for identifying bearing specifications. Is to be. In addition,
This color development treatment is a reaction with oxygen in the air at high temperature to form an oxide film on the metal surface and color it (tempered color)
Is a process of performing

The coloring process for the outer surface of the race 1 will be described below.

The material of the race 1 is a metal material. There are various kinds of metal materials, for example, high carbon chromium bearing steel, case hardened steel, stainless steel, induction hardened steel, high speed tool steel, stellite, Cemented carbide, etc.

In the embodiment, first, a metal material which is a material of a lace is subjected to plastic processing such as pressing, hardening processing by quenching and tempering, and finishing processing such as a barrel after a normal lace manufacturing process. The color forming process in the present embodiment is performed. This will be described below.

That is, the metal material which is the material of the race is
Has metallic luster. This metal material is subjected to plastic working such as pressing. At this stage, the metal material still retains the metallic luster.

Then, a hardening treatment is applied to the metal material of the lace material subjected to the plastic working.

Quenching in this hardening process is a process of heating a metal material to high temperature in the atmosphere and then cooling it in oil. In this case, since the quenching temperature is high, the surface of the metal material is black and the surface state is poor, and the metal material is unsuitable as it is. Further, in the above-mentioned quenching, a slight carburizing gas is flowed to prevent decarburization instead of a mere high temperature treatment in the atmosphere. In this case, it is important that the atmosphere is aerobic.

After the quenching, a tempering process is performed. Tempering is a process of heating and cooling the material after quenching to a temperature below a predetermined transformation point to make the structure of the material stable and remove residual stress to obtain required properties and conditions.

In the tempering process, the surface of the metal material is also colored. However, since the surface of the metal material is colored in a dark color at the stage of the tempering process, the tempering process has little effect in terms of coloring.

After a hardening process, which is a normal process for such a bearing, a finishing process using a barrel is performed. The finishing treatment is to remove an acute angle or the like of the metal material. At this time, the coloring on the surface of the metal material is removed, and the metal luster returns to the surface. Thus, the production of a finished product of a normal race is completed.

The present embodiment is characterized in that thereafter, the outer surface of the race 1 is subjected to the coloring process as shown in FIG. The color A serves as specification identification for other bearings. In this case, in this embodiment, in the same tempering process as the tempering in the hardening process which is a general manufacturing process of the bearing, a color A for specification identification is formed simply by lowering the tempering temperature. Therefore, the bearing structure is suitable for mass production of the bearing, and a special specification identification forming device is not required, and the bearing structure has a low manufacturing cost.

In the above description, the color forming process is performed on the entire bearing component such as the race 1. However, the color forming process may be partially performed on the outer peripheral surface and the end surface of the bearing component. FIG. 3 and FIG. 4 are examples in the case where such a partial coloring process is performed.

First, referring to FIG. 3, a masking apparatus B for selectively performing the color developing process on the outer peripheral surface or the end surface of the race 1 and the color developing process by the masking device B will be specifically described.

A number of races 1 are stacked on a shaft 11 erected on a base 10. And the top race 1
The sealing cap 12 is screwed on, each race 1 is exposed only on the outer surface, the other parts are stacked on top of each other and masked, and the top is sealed on top.
Masked with 2.

In this case, if the masking of the masked portion is insufficient, the masked portion is prevented from being oxidized by using a suitable jig or the like so as not to come into contact with oxygen in the air to form a color. It is good to suppress.
Then, in this state, tempering is performed again at a desired temperature equal to or lower than the tempering temperature.

As a result, the race 1 in which the processing of the color A is applied to the outer peripheral surface and the end surface in one tempering process is completed.

According to the specification identification formation by the masking device B, a race 1 structure in which the same color A is formed on the same outer peripheral surface and the same end surface is obtained.

FIG. 4 shows another masking apparatus C for selectively applying a color development A to the outer peripheral surface and the end surface of the race 1.

First, in the case of this masking device C, FIG.
As in the case of the masking device B, a large number of races 1 are stacked on a shaft 11 erected on a base 10 and a sealing cap 12 is screwed on the uppermost race 1 in the same manner. A mask 13 having one or more windows and slits 13a for selectively exposing a part of the outer surface of each race 1 is covered.

It is preferable that the mask 13 prevents other portions of the outer surface of the race 1 from being exposed to oxygen in the air. Further, since the tempering temperature for color development is close to 200 ° C., the material of the mask 13 corresponding to the temperature may be appropriately selected.

In FIG. 4, the slits 13a are vertically elongated in the direction in which the races 1 are stacked. However, by providing one or more slits 13a, for example,
For the bearing of the first specification, coloring is performed using the mask 13 having one slit 13a, and for the bearing of the second specification,
Color development is performed using a mask 13 having two slits 13a, and for a bearing of the third specification, color development is performed using a mask 13 having three slits 13a. Are different, the specification of each bearing can be identified. In short, the mask 13
By changing the position of the slit 13a, increasing or decreasing the number of slits, changing the shape of the window, etc., various forms of color development are possible,
This makes it possible to identify each specification in the form of coloring of the outer peripheral surface and end surface of the race 1 of each bearing.

The above-described color development in FIGS. 1 to 4 is a form of color development due to oxidation of the race surface, and a film is formed on the race surface by the oxidation. Since the thickness is less than the allowable value of the race size and the influence on the bearing size is negligible, the reliability of the bearing is maintained.

Further, since no extraneous environmentally harmful substances are used in the color forming process itself, there is no influence on the environment, and this is a preferable process.

Further, since this coloring is carried out after the above-mentioned curing treatment, it is suitable for mass production of races, and the cost can be reduced.

In the above embodiment, the specification is identified based on the color developed by tempering. However, the following embodiment is also conceivable.

That is, in this embodiment, first, the metal material as the material of the lace is subjected to plastic working such as pressing and the like, and an acute angle is formed with a barrel (raw barrel), followed by a bright heat treatment.

The bright heat treatment in this case is a quenching (bright quenching) in which the quenching is performed in an oxygen-free atmosphere such as in a vacuum in a hardening process consisting of quenching and tempering.
Processing. In the case of such bright quenching, oxidation does not occur at the time of the quenching, and after the quenching, the metallic luster is maintained and the surface state is good. Thereafter, tempering is performed at a required temperature in the air. At this time, a colored layer is formed on the surface of the metal material. Then, this colored layer is removed by a barrel.

As described above, in the form of the hardening process including the bright quenching process, unlike the above-described hardening process including the normal quenching process, the specification can be identified by removing the layer colored by the barrel. Becomes possible.

In the case of such a form in which bright quenching is performed, a hardening treatment including bright quenching is performed on both races, and the colored layer is removed by barrel processing or the like on only one of the races. The two races can be distinguished from each other, and the bearing mounting direction can be easily determined, which is convenient.

The present invention is not limited to the above embodiment, and various applications and modifications are possible.

(1) In the embodiment, the thrust needle roller bearing is described as an example. However, the bearing to which the present invention is applied is not limited to this bearing, but may be a radial type or a thrust type. Regardless of the above, all the bearings are configured to include at least a pair of races (inner and outer rings) and rolling elements as necessary, and also to include a retainer as necessary. In addition, a type having no bearing ring, such as a rolling bearing called a cage-and-roller, is also applicable to the present invention. The coloring may be applied to a cage of a radial type needle roller with a cage (bearing only at the cage). In this case, it is the same as the above embodiment except that the quenching process is carburizing quenching.

(2) In the embodiment, the race is subjected to the color development process. However, the bearing component for performing the color development process is not limited to the race, but may be any of rolling elements, cages, and other bearing components. .

(3) The present invention is directed to the structure of a bearing, but also includes an invention of a method for forming specification identification marks, an invention of a method of manufacturing a bearing, and an invention of a method of manufacturing a bearing component. That is, a hardening process including quenching and tempering is performed on each bearing component such as a metal race or a rolling element that constitutes a bearing, and one or more of the bearing components after the hardening process are performed. A plurality is subjected to heat treatment at a desired temperature lower than its tempering temperature to form a color, and this color is used as specification identification for another bearing.

[0059]

According to the first and second aspects of the present invention, the bearing dimensions and strength are not affected, the handling is stable, and there is no influence on the environmental load. Therefore, it is suitable for mass production and the manufacturing cost is low. It is possible to provide a rolling bearing provided with specification identification that requires only a short time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an upper half of a thrust needle roller bearing according to an embodiment of the present invention.

FIG. 2 is a perspective view of a race of the roller bearing of FIG. 1;

FIG. 3 is a longitudinal sectional view from the front of a masking device for applying a color developing process to a race.

FIG. 4 is a partially cutaway front view showing another masking device for applying a color developing process to a race.

[Explanation of symbols]

 1, 2 Race 3 Needle roller 4 Cage A Coloring

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Katsuhiko Chihara 3-5-8 Minamisenba, Chuo-ku, Osaka-shi F-term (reference) in Koyo Seiko Co., Ltd. 3J101 AA14 AA32 AA42 AA53 AA62 AA72 BA51 DA01 EA02 FA44 FA46 FA60

Claims (4)

[Claims] In the present invention, any one of the bearing components, which have been subjected to a finishing process after being subjected to a hardening process including quenching and tempering, are subjected to a finishing process. A rolling bearing, characterized in that the surface of the bearing component is colored for specification identification by performing a heat treatment at a desired temperature lower than the tempering temperature. 2. The rolling bearing according to claim 1, further comprising: two bearing rings that are relatively rotatable as the bearing component, and at least one of the bearing rings is colored for specification identification. A rolling bearing. 3. The rolling bearing according to claim 2, wherein the coloring is selectively applied to at least an outer peripheral surface or an end surface of the race. 4. A bearing component which has been subjected to a hardening process of quenching the bearing component in an oxygen-free atmosphere and then tempering in air, a layer colored during tempering in the hardening process is provided. Has been removed for specification identification,
A rolling bearing, characterized in that: