JP2010117033A - Rolling bearing and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing equipped with specification identification, having no influence on a bearing dimension and bearing strength, stable in handling, also having no influence on environmental load, suitable for mass production, and providing a low manufacturing cost. <P>SOLUTION: Two relatively rotatable bearing rings are finished after hardening treatment including hardening and tempering is performed. After the finishing treatment, heat treatment at a required temperature lower than the tempering temperature is given to at least either of the two bearing rings, which gives color for the specification identification on the surfaces of the bearing rings. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing composed of bearing components including a metal bearing ring, rolling elements, and the like, and more particularly to specification identification thereof.

  Even if the type of encapsulated grease and other specifications are different, the specifications of multiple rolling bearings with the same appearance cannot be identified. Therefore, when assembling a plurality of such rolling bearings in an apparatus, it is desirable to attach an identification display indicating that the specifications are different from those of other rolling bearings in order to improve the assembling workability.

  For conventional rolling bearings, specifications are identified by engraving symbols and letters on the specifications of the raceway surface, specifications identified with or without copper plating, or the raceway surface is blackened. There are those with specification identification.

  However, in the case of a rolling bearing provided with specification identification by the above-mentioned engraving, if it is further downsized, the engraving form on the surface of the bearing ring becomes difficult to distinguish, and the assembling workability is not improved so much.

  In addition, in the case of a rolling bearing having specification identification by copper plating, the plating is easily peeled off depending on handling, and the specification identification is not stable.

  Further, in the case of a rolling bearing provided with specification identification by black dyeing on the surface of the bearing ring, the black dyeing component often becomes an environmental load depending on the usage environment of the rolling bearing, which is not necessarily preferable.

  Furthermore, each of the above specification identification forms is a specification identification formation process that is completely separate from the general manufacturing process of rolling bearings, and is not suitable for mass production of rolling bearings, and requires a special specification identification formation device. However, this structure has an extra high manufacturing cost.

  Therefore, the present invention provides a rolling bearing having a specification identification that does not affect the bearing size and bearing strength, is stable in handling, has no influence on the environmental load, is suitable for mass production, and can be manufactured at low cost. It aims at providing the manufacturing method.

  According to the first rolling bearing of the present invention, the finishing is performed on at least one of the two bearing rings which are subjected to a finishing process after being subjected to a hardening process including quenching and tempering and which are relatively rotatable. By performing a heat treatment at a desired temperature lower than the tempering temperature after the processing, the surface of the raceway is colored for specification identification.

  The first method of manufacturing a rolling bearing according to the present invention includes a step of subjecting two bearing rings capable of relative rotation to hardening treatment including quenching and tempering, and two bearing rings subjected to the hardening treatment. And applying a heat treatment at a desired temperature lower than the tempering temperature to at least one of the two bearing rings subjected to the finishing process. And a step of coloring the surface for specification identification.

  According to the first aspect of the present invention, since the color development in the heat treatment at a desired temperature lower than the tempering temperature after the curing process is the specification identification, the bearing is small unlike the specification identification by the conventional engraving. Therefore, the bearing can accurately recognize the specification identification, and can easily be distinguished from other bearings having the same external appearance in terms of specifications, and the above-described assembly workability can be improved.

  According to the first aspect of the present invention, since the color is generated by a heat treatment at a desired temperature lower than the tempering temperature after the curing process, the film thickness of the oxide film due to the color development is thin and is affected by the bearing size and the bearing strength. There are no bearings.

  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 a specification identification that causes an environmental load on the usage environment of the bearing, which is preferable for recent environmental problems. It is a bearing.

  In particular, in the case of the first aspect of the present invention, specification identification is formed by simply lowering the tempering temperature in the same process as the curing process, which is a general manufacturing process of bearings. Therefore, a special specification identification forming device is not required and the manufacturing cost is low.

  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 raceway by masking. In such a case, since the color is selectively applied to the outer peripheral surface and the end surface, it is more preferable because the selected color can be used to identify different types of bearings having different specifications.

  The second rolling bearing of the present invention is the above-mentioned at least one of the two bearing rings that are relatively rotatable and that has been subjected to a hardening process of quenching in an oxygen-free atmosphere and then tempering in air. A layer colored during tempering in the curing process is removed for specification identification.

  The second rolling bearing manufacturing method of the present invention includes a step of performing a hardening process in which two bearing rings that are relatively rotatable are quenched in an oxygen-free atmosphere and then tempered in air. Removing at least one of the two race rings subjected to the treatment for color identification at the time of tempering in the curing treatment.

  According to the second aspect of the present invention, since the colored layer that has been tempered in the air is removed and the specification identification is shown, the bearing is downsized unlike the conventional specification identification by engraving. The bearing is capable of accurately recognizing the specification identification, easily distinguishing the specification from other bearings having the same appearance, and the above-described assembly workability is improved.

  According to the first and second aspects of the present invention, specification identification that does not affect the bearing size and bearing strength, is stable in handling, has no influence on the environmental load, is suitable for mass production, and can be manufactured at low cost. A provided rolling bearing and a method for manufacturing the same can be provided.

The longitudinal cross-sectional view which shows the upper half of the thrust needle roller bearing which concerns on embodiment of this invention 1 is a perspective view of the race of the roller bearing of FIG. Longitudinal sectional view from the front of the masking device for coloring the race Front view showing a part of another masking device for applying a coloring process to the race.

  The details of the present invention will be described below with reference to FIGS. In the embodiment of the present invention, description will be made by applying to a thrust needle roller bearing as a rolling bearing, but the present invention may be applied to other rolling bearings such as a needle roller bearing with a cage.

  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 the race of the bearing of FIG. 1, and FIG. FIG. 4 is a front view showing a part of another masking device for performing a coloring process on a race in a cutaway view.

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

  Both races 1 and 2 are disposed opposite to each other in the axial direction as raceways, and one race 1 is provided with one outer peripheral flange 1b in the axial direction at the outer peripheral end of the annular plate 1a. The race 2 is provided with the other inner peripheral flange 2b in the axial direction at the inner peripheral end of the annular plate 2a.

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

  In this bearing, a plurality of needle rollers 3 held in the pocket 4c of the cage 4 are interposed in the annular space in the radial direction of the flanges 1b and 2b of both races 1 and 2. .

  The bearing of the embodiment having the above-described configuration is characterized in that, among these bearing components including the races 1 and 2 and the needle rollers 3, the finishing process is performed after the curing process is performed. For any one of the bearing components, after the finishing process, for example, one race 1 is subjected to a heat treatment at a desired temperature lower than the tempering temperature, thereby identifying the bearing specification on the surface of the race 1. It is that the color development processing for performing is performed. The coloring process is a process of coloring (temper color) by reacting with oxygen in the air at a high temperature to form an oxide film on the metal surface.

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

  The material of Race 1 is a metal material, but there are various types of metal materials such as 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, the metal material which is the material of the race is subjected to the present process after the normal race manufacturing process of plastic processing such as press, hardening processing by quenching and tempering, and finishing processing such as barrel. Perform color development in the form. This will be described below.

  That is, the metal material that is the material of the lace has a metallic luster. The metal material is subjected to plastic working by pressing or the like. At this stage, the metal material still maintains a metallic luster.

  And the hardening process is given with respect to the metal material of the lace raw material which gave plastic working.

  The quenching in this curing process is a process in which a metal material is heated at a high temperature in the atmosphere and then cooled 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 as it is, it is not suitable as a bearing. Further, in the above quenching, a slight carburizing gas is flowed to prevent decarburization rather than a high temperature treatment in the air. In this case, it is important to be in an aerobic environment.

  Then, a tempering process is performed after the quenching. Tempering is a process of heating and cooling to a temperature equal to or lower than a predetermined transformation point in order to make the structure of the material after quenching a stable structure and remove residual stress to obtain the required properties and state.

  Also in this tempering process, the surface of the metal material is colored, but since it is colored in a deep color at the stage of the tempering process, this tempering process has no significant influence in terms of coloring.

  After a curing process, which is a normal process for such bearings, a finishing process is performed using a barrel. The finishing treatment is to remove acute angles or the like of the metal material. At this time, the coloration on the surface of the metal material is removed, and the metallic luster returns to the surface. In this way, a finished product of a normal race is manufactured.

  The present embodiment is characterized in that, after this, the coloring process is performed on the outer surface of the race 1 as shown in FIG. This color A is the specification identification for other bearings. In this case, in this embodiment, in the same tempering process as the tempering in the curing 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 structure is suitable for mass production of bearings, a special specification identification forming device is not required, and the bearing cost is low.

  In the above, the coloring process is applied to the entire bearing component such as the race 1, but the coloring 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 partial color development processing is performed.

  First, with reference to FIG. 3, the masking apparatus B for performing selective color development processing on the outer peripheral surface or end surface of the race 1 and the color processing process by the masking device B will be specifically described.

  A large number of races 1 are stacked on a shaft 11 erected on the base 10. Then, a sealing cap 12 is screwed onto the uppermost race 1 so that only the outer surface of each race 1 is exposed, the other portions are stacked on top of each other and masked, and the uppermost portion is sealed. Masked with a cap 12 for use.

  In this case, if the masking of the masked portion is insufficient, the masked portion is prevented from being oxidized by touching oxygen in the air with an appropriate jig or the like to prevent color development. It is good to make it. In this state, tempering is performed again at a desired temperature lower than the tempering temperature.

  As a result, the race 1 in which the color A processing is performed on 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, the race 1 structure is formed in which the same color A is formed on the same outer peripheral surface or end surface.

  FIG. 4 shows another masking device C for subjecting the coloring A to a selective coloring process on the outer peripheral surface and end face of the race 1.

  First, in the case of this masking device C, as in the masking device B of FIG. 3, a large number of races 1 are stacked on the shaft 11 erected on the base 10, and a sealing cap 12 is placed on the uppermost race 1. The points to be screwed are the same, but 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 to be masked from coming into contact with 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 the case of FIG. 4, the slit 13 a is vertically long in the stacking direction of the race 1, but the slit 13 a is provided in the first specification bearing by, for example, one or more slits 13 a. Coloring is performed using the mask 13 provided with one, and coloring is performed using the mask 13 provided with two slits 13a on the bearing of the second specification, and the slit 13a is provided on the bearing of the third specification. By performing color development using the three masks 13 provided, the number of the color A is different for each specification, so that the specification of each bearing can be identified. In short, various forms of color development are possible by changing the position of the slits 13a of the mask 13, increasing or decreasing the number of slits, changing the window shape, and the like, thereby enabling the color development of the outer peripheral surface and end face of the race 1 of each bearing. Thus, each specification can be identified.

  1 to 4 described above is a form of coloration caused by oxidation of the lace surface, a film formed by the oxidation is formed on the lace surface. Since the influence on the bearing size is negligible if it is less than the allowable value of the race size, the reliability of the bearing is maintained.

  In addition, since no extra environmentally hazardous substances are used in the color development process itself, it is a preferable process with no influence on the environment.

  Further, since this color development is performed after the curing process, it is suitable for mass production of lace and is inexpensive.

  In the above embodiment, the specification is identified by coloring by tempering, but the following forms are also conceivable.

  That is, in this embodiment, first, a metallic material, which is a material of a race, is subjected to plastic working such as pressing and an acute angle is taken with a barrel (raw barrel), and then a bright heat treatment is performed.

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

  Thus, in the form of the curing process including the bright quenching process, the specification can be identified by removing the colored layer by the barrel, unlike the curing process including the normal quenching process described above. Become.

  In the case of such a form of bright quenching, both races can be cured by performing hardening treatment including bright quenching on both races and removing the colored layer by barrel treatment or the like only on one race. This makes it possible to easily distinguish the bearing assembly direction.

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

  (1) In the embodiment, a thrust needle roller bearing has been described as an example. However, the bearing to which the present invention is applied is not limited to this bearing, regardless of a radial type or a thrust type. The bearing component includes at least a pair of bearing rings (inner ring, outer ring) and rolling elements, and is also provided with a cage as necessary. In addition, a type that does not include a race, such as a rolling bearing called a cage-and-roller, is also an object of application of the present invention. In addition, you may give the said color to the holder | retainer of a radial type needle roller with a holder | retainer (bearing only of a holder | retainer place). In this case, it is the same as that of the said embodiment except a hardening process becoming carburizing hardening.

  (2) In the embodiment, the coloring process is performed on the race. However, the bearing component that performs the coloring process may be not only the race but also any rolling element, cage, or other bearing component.

  (3) The present invention is directed to the structure of the bearing, but also includes the invention of the specification identification mark forming method, the invention of the bearing manufacturing method, or the invention of the bearing component manufacturing method. That is, a hardening process including quenching and tempering is performed on each bearing component such as a metal bearing ring and rolling elements constituting the bearing, and one or more of the bearing components after the hardening process are performed. A plurality of heat treatments are performed at a desired temperature lower than the tempering temperature to develop a color, and this color is used as a specification identification for other bearings.

1, 2 Races 3 Needle rollers 4 Cage A Coloring

Claims (6)

  After at least one of the two race rings that are subjected to a hardening process including quenching and tempering and then subjected to a finishing process, and are relatively rotatable, the tempering is performed after the finishing process. A rolling bearing characterized in that a color for specification identification is applied to the surface of the raceway ring by performing a heat treatment at a desired temperature lower than the temperature. The rolling bearing according to claim 1,
The rolling bearing according to claim 1, wherein the coloring is selectively applied to at least an outer peripheral surface or an end surface of the race by masking.   Color was developed during tempering in at least one of the two race rings that are relatively rotatable and subjected to a curing process in which they are tempered in an oxygen-free atmosphere and then tempered in air. Rolling bearing, characterized in that the layer is removed for specification identification. Applying a hardening process including quenching and tempering to the two race rings which are capable of relative rotation;
Applying a finishing process to the two bearing rings subjected to the curing process;
Applying at least one of the two bearing rings subjected to the finishing process to a color for specification identification on the surface of the bearing ring by performing a heat treatment at a desired temperature lower than a tempering temperature thereof; A method for manufacturing a rolling bearing, comprising: In the manufacturing method of the rolling bearing of Claim 4,
A method of manufacturing a rolling bearing, wherein the coloring is selectively applied to at least an outer peripheral surface or an end surface of the raceway by masking. A step of performing a curing process of quenching in an oxygen-free atmosphere and then tempering in the air with respect to the two race rings that are capable of relative rotation;
A rolling bearing comprising: removing at least one of the two bearing rings subjected to the curing process a colored layer at the time of tempering in the curing process for specification identification. Manufacturing method.

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