JP2003301847A - Bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device comprising a plurality of bearing ring members provided in parallel in the axial direction capable of restricting fretting abrasion at abutted parts in the axial direction for preventing the deterioration of a bearing life caused by fretting abrasion. <P>SOLUTION: Diamond-like carbon films 16 are formed on one and the other end surfaces 14a and 14b of a spacer 14. The spacer 14 is thus disposed between a pair of inner rings (the bearing ring members) 12a and 12b provided in parallel in the axial direction with the diamond-like carbon films 16 between. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device that supports an axle of a railway vehicle.

[0002]

2. Description of the Related Art For example, as a bearing device for rotatably supporting an axle of a railroad vehicle, one having a double row tapered roller bearing shown in FIG. 8 has been conventionally used. In the figure, this conventional bearing device is provided with a double-row tapered roller bearing 50 that supports an axle A, and a front lid 61 and a rear lid 62 that are fixed to the tip and the base of a journal portion A1 of the axle A, respectively. Has been. Further, this bearing device includes an oil draining sleeve 63 and a sealing device 64 provided on the front lid 61 side, and a rear lid 62.
And a sealing device 65 provided on the side of the bearing 50.
It is designed to seal the inside.

The double-row tapered roller bearing 50 has a single outer ring 51 integrally formed as a whole, and a pair of inner rings 52a which are arranged side by side in the axial direction and integrally rotatably mounted on the axle A.
52b, a tapered roller 53 rotatably arranged between the inner and outer races, and an annular spacer 54 interposed between the inner races 52a and 52b. The outer ring 51 and the inner rings 52a and 52b are made of, for example, bearing steel, and the spacer 54 is made of carbon steel for machine structure. Further, the outer ring 51 is provided with a lubrication hole 51a to supply lubricating oil such as grease to the rolling contact portion between the inner and outer rings and the tapered roller 53.

[0004]

By the way, in the conventional bearing device as described above, due to the influence of the bending of the axle A, fretting wear is caused at the abutting portion of the pair of inner rings 52a, 52b and the spacer 54 in the axial direction. It happened.
More specifically, the axle A is subjected to radial and axial loads and shocks as the railroad vehicle travels, generating vibrations, and the axle A is bent such as slightly bent. When such bending of the axle A occurs, the abutting portions, that is, the one and the other end surfaces 54a, 54 of the spacer 54 are formed.
Fretting wear may occur in which b and the axial end surfaces 52a1 and 52b1 of the inner rings 52a and 52b that contact the end surfaces 54a and 54b, respectively, repeatedly rub against each other and wear. Further, when the above fretting wear occurs, metal wear powder is generated, and this metal wear powder contaminates the lubricating oil and deteriorates the lubricating oil, or the rolling contact between the inner and outer races and the tapered roller 53. However, there is a problem in that the surface of the inner and outer rings and the surface of the tapered roller 53 may be damaged by entering the inner part and the life of the bearing may be shortened.

In particular, in the railway vehicles using the conventional bearing device as described above, downsizing and maintenance-free for a long period of time have been demanded recently, and the downsizing of the bearing device accompanying the downsizing has contributed to the reduction of the size. As a result of the necessity of downsizing the bearing 50 of the apparatus as well, the contact surface pressure at each of the above-mentioned abutting portions becomes large and fretting wear is likely to occur. On the other hand, since the inspection interval is long, it is difficult to detect fretting wear at an early stage, and it is difficult to prevent vehicle troubles such as poor running of the vehicle due to fretting wear.

Therefore, in view of the above-mentioned conventional problems, the present invention suppresses fretting wear at the abutting portion in the axial direction in a bearing device in which a plurality of bearing ring members are arranged side by side in the axial direction. Therefore, it is an object of the present invention to provide a bearing device capable of preventing the reduction of the bearing life due to fretting wear.

[0007]

A bearing device of the present invention is a bearing device having a bearing having an inner ring and an outer ring, and rolling elements rotatably arranged between the inner ring and the outer ring. At least one race ring of the inner ring and the outer ring is a single row or a plurality of rows of a pair of race ring members arranged in parallel with their end faces abutting each other, and each butting end face of the pair of race ring members A diamond-like carbon film is formed on either one of the above (Claim 1).

In the bearing device configured as described above (claim 1), the diamond-like carbon film formed on the abutting end face of one of the pair of bearing ring members has fretting wear at the abutting portion in the axial direction. Suppress.

Further, the bearing device of the present invention is a bearing device including a bearing having an inner ring and an outer ring, and a rolling element which is rotatably arranged between the inner ring and the outer ring. At least one raceway ring is formed by arranging a pair of raceway ring members arranged in parallel with a spacer interposed therebetween in a single row or a plurality of rows, and one end face of the spacer and a raceway ring member in contact therewith. A diamond-like carbon film is formed on either one of the end faces and on the other end face of the spacer and on one of the end faces of the bearing ring member in contact therewith (claim 2). .

In the bearing device configured as described above (Claim 2), either one of the end faces of the spacer and one of the race ring members in contact therewith, and the other spacer in contact with the spacer. The diamond-like carbon film formed on either one of the end faces of the wheel member suppresses fretting wear at the abutting portions in the axial direction.

The bearing device (claim 1 or 2)
In the above, the diamond-like carbon film may contain tungsten (claim 3). in this case,
Tungsten contained in the diamond-like carbon film enhances the adhesion between the diamond-like carbon film and the end face on which the diamond-like carbon film is formed, and firmly forms the diamond-like carbon film on the end face. You can

In the above bearing device (any of claims 1 to 3), a chromium film may be formed between the diamond-like carbon film and an end face on which the diamond-like carbon film is formed ( Claim 4). In this case, the chromium film can enhance the adhesion to the end face of the diamond-like carbon film, and the diamond-like carbon film can be firmly formed on the end face.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the bearing device of the present invention will be described below with reference to the drawings.
In the following description, in order to facilitate comparison with the conventional example, a case where the present invention is applied to a bearing device that rotatably supports an axle of a railway vehicle will be described as an example. FIG. 1 is a cross-sectional view showing a configuration of an axle journal portion of a railway vehicle using a bearing device according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a main configuration of the bearing device shown in FIG. Is.

In FIG. 1, the bearing device of the present embodiment is
Axle A is installed at the bottom of a bogie (not shown) of a railroad vehicle.
Double row tapered roller bearing 1 for rotatably supporting the
The front lid 2 fixed to the tip of the journal portion A1 by a bolt 7 and the rear lid 3 integrally rotatably attached to the base portion of the journal portion A1. Further, the bearing device includes a sealing device 5 having an annular oil draining sleeve 4 and an annular sealing member arranged between the bearing 1 and the front lid 2, and arranged between the bearing 1 and the rear lid 3. And a sealing device 6 having an annular sealing member is provided to prevent foreign matter such as muddy water and dust from entering the inside of the bearing and prevent lubricating oil such as grease from leaking out from the inside of the bearing. I'm out. A wheel (not shown) is attached to the axle A inside the journal A1 (on the right side in the figure) so as to be rotatable integrally therewith, so that the truck can run on a rail. Further, by adjusting the tightening torque of the bolt 7, it is possible to change the axial mounting position of the bearing 1 sandwiched between the front lid 2 and the rear lid 3 via the oil draining sleeve 4. Has become.

The double row tapered roller bearing 1 is attached to an outer ring 11 fixed to an axle housing (not shown) provided on the bogie side and an axle A so as to be integrally rotatable, and arranged in parallel in the axial direction. Between the pair of inner rings 12a, 12b as a plurality of raceway members, the tapered rollers 13a, 13b as rolling elements rotatably arranged between the inner and outer rings, and the pair of inner rings 12a, 12b. It has an annular spacer 14 interposed therebetween and cages 15a and 15b for retaining the tapered rollers 13a and 13b, respectively.

The outer ring 11 is made of, for example, bearing steel (SUJ).
2 etc.) is a single one integrally formed as a whole,
A pair of cone-shaped outer ring raceways 11a and 11b are provided on the inner circumference thereof. The pair of inner rings 12a, 12b are formed of the bearing steel. Also, the inner ring 12
Conical inner ring raceways 12a1 and 12b1 facing the outer ring raceways 11a and 11b, respectively, are provided on the outer periphery of a and 12b. In the department
Corresponding tapered rollers 13a and 13b roll. Also,
The lubricating oil is supplied to the rolling contact portion through an oil slide hole 11c penetrating the axial center portion of the outer ring 11.

The spacer 14 is made of carbon steel (for example, SUS).
440C) and other raw materials. Further, as shown in FIG. 2, the spacer 14 has one and the other axial end surfaces 14a, 14 which are abutted against the inner rings 12a, 12b.
b, Diamond-like carbon (Diamond-Like Car
bon (hereinafter also referred to as “DLC”) film 16 is formed, and the spacer 14 has the inner ring 12a, with the DLC film 16 interposed therebetween.
Axial end faces (butt end faces) 12a2, 12 of 12b
It is in contact with b2.

The DLC film 16 has a thickness of 1.0 to 5.0 μm formed by, for example, a sputtering method using carbon as a target.
The Vickers hardness of 1000 to 2000 (H
v) A hard film having a hardness of about v) is formed. This D
The surface roughness of the LC film 16 is, for example, the center line average roughness (Ra).
Is controlled to 0.1 μm or less. Also, this DLC
The film 16 is bonded to the end faces 14a and 14b with a predetermined adhesive force (at least 40N, preferably 60N) so as not to peel off from the end faces 14a and 14b. Further, the DLC film 16 is a film having a low aggression and friction coefficient to the mating material with which it abuts, excellent abrasion resistance, and a slight self-lubricating property. The axial end faces 12a2, 12b2 of the inner ring 12 are also provided. Fretting wear between and is suppressed.

DLC film 16 formed by the above-mentioned sputtering method
In forming the film, the pressure in the vapor deposition chamber into which the introduction gas such as argon gas or hydrocarbon gas is introduced is 10 ⁻³ to 10 (Tor).
r) and a discharge voltage of 100 to 2000 (V) and a current of 2 to 10 (A), carbon is vapor-deposited on the spacer end faces 14a and 14b, which are target surfaces. As a result, the DLC film 16 having the above-mentioned film thickness, hardness, etc. and having an amorphous structure in which a graphite (SP ² ) structure and a diamond (SP ³ ) structure coexist is formed on the end faces 14a, 1a.
Formed on 4b. When forming the DLC film 16, the spacer surface such as the inner peripheral surface other than the target surface is masked by a mask member so that carbon does not adhere. Further, if the thickness of the DLC film 16 is less than 1.0 μm, the abrasion resistance is insufficient, and 5.0
If it exceeds μm, not only the cost becomes enormous, but also the internal stress increases due to the excessively large film thickness, which causes peeling. Therefore, the preferable film thickness of the DLC film 16 is 1.
The thickness is 0 to 5.0 μm, and more preferably 3.0 μm. Further, if the adhesion of the DLC film 16 to the end faces 14a and 14b is less than 40N, the DLC film 16 concerned.
Peeling easily occurs. Further, if the hardness of the DLC film 16 is less than 1000 in Vickers hardness (Hv), the abrasion resistance is insufficient, and if it exceeds 2000, the internal stress becomes large, which causes peeling.

In addition to the above-mentioned sputtering method, other physical vapor deposition method (PVD) such as ion plating method by ion beam vapor deposition using benzene as a source gas, chemical vapor deposition method (CVD), or plasma jet is used. The DLC film 16 may be formed by using a thermal spraying method such as plasma spraying. Further, the spacer end surfaces 14a and 14b are roughened by knurling or the like to form the DLC film 16
The adhesiveness (adhesive strength) to the end surfaces 14a and 14b on which is formed may be increased. However, since PVD such as the above-mentioned sputtering method is a film forming method utilizing a physical mechanism, it does not depend on the material of the base (spacer 14), and compared to other film forming methods Since high adhesion can be easily ensured, it is optimal for forming the DLC film 16.

The verification test conducted by the inventors of the present invention will be described with reference to FIG. In this verification test, the following ball-on-disk test was performed to verify the opponent attack and friction coefficient of the DLC film 16. Specifically, as a disc-shaped test sample, a DLC film 16 having a film thickness of 1.0 μm was formed on SUJ2, which is equivalent to the present invention, a comparative product 1 made of SUJ2 having no film and a film thickness of 1 Comparative products 2 and 3 in which a chromium nitride (CrN) film and a nickel phosphide (NiP) film having a thickness of 0.0 μm were formed on SUJ2 were prepared. Also, the diameter is 5 /
A 32-inch SUS440C ball was prepared as a mating material, and a plurality of balls were circumferentially arranged on each of the above test samples. And the sliding speed for the ball is 0.1m
/ S, and each test sample was rotated under a load with a maximum contact surface pressure of 1.0 GPa so that the sliding distance with respect to the ball was 360 m, and the radius of the wear mark generated on the ball surface and each test The friction coefficient of the sample was determined.

As shown in FIG. 3 (a), in the product of the present invention, the radius of the wear mark generated on the ball is reduced to 1/3 or less of that of the comparative products 1 to 3, and the product of the counterpart material is reduced. It was confirmed that the aggression was low. In particular, the comparative product 1 corresponding to the combination of the inner ring and the spacer in the above conventional example has a wear mark of 0.7 mm, whereas the comparative product 1 of the present invention has a wear mark of 0.7 mm.
When the spacer 14 on which the DLC film 16 is formed is used, the wear with the axial end surface of the inner ring is sufficiently suppressed, and metal wear powder is generated from the axial end surface. It has become clear that this can be suppressed as much as possible. In addition, as shown in FIG. 3B, the friction coefficient of the product equivalent to the present invention is as small as 1/2 or less as compared with that of the comparative products 1 to 3, and especially 1 of the comparative product 1 (conventional example). It was proved to be as low as / 3 or less. Further, it was confirmed that the film equivalent to the present invention had almost no change in film thickness before and after the test, and had self-lubricating property and excellent wear resistance.

In the bearing device of this embodiment constructed as described above, the DLC film 16 is formed on the spacer end faces 14a, 14b, and the spacer 14 and the inner rings 12a, 12b are interposed with the DLC film 16 interposed. Abut. As a result, the DLC film 16 on the spacer end faces 14a, 14b, the inner ring 12a,
Even if the axial end faces 12a2, 12b2 of the shaft 12b repeatedly rub against each other due to the influence of the bending of the axle A, fretting wear at the abutting portion in the axial direction can be suppressed. As a result, unlike the above-mentioned conventional example, it is possible to suppress the generation of metal wear powder due to fretting wear as much as possible, and it is possible to prevent the contamination of the lubricating oil by the metal wear powder, and thus the deterioration of the lubricating oil. Furthermore, the metal abrasion powder is used for the inner and outer rings and the tapered rollers 13a, 13
It is possible to prevent damage to the surfaces of the inner and outer races, the surfaces of the tapered rollers 13a and 13b, and the like by invading the rolling contact portion with b and prevent the bearing life from being shortened. Moreover, since it is possible to suppress the generation of metal abrasion powder as much as possible, it is possible to prevent rolling defects from occurring in the tapered rollers 13a and 13b, and it is possible to prevent abnormal noise and vibration due to the rolling defects from occurring, and also the bearing 1 It is possible to prevent the supporting accuracy of the device from decreasing. Further, since fretting wear at the butted portion in the axial direction can be suppressed, it is possible to easily configure a bearing device suitable for a railway vehicle or the like that requires compactness and maintenance-free for a long period of time.

FIG. 4 is an enlarged sectional view showing the structure of the main part of the bearing device of another embodiment. In the figure, in this embodiment, instead of the DLC film 16 described above, a DLC film 17 containing tungsten is provided on one and the other end faces 1 of the spacer 14.
4a, 14b. The DLC film 17 has a diamond-like carbon film containing tungsten to enhance the adhesion between the DLC film 17 and the end faces 14a and 14b (formation faces) on which the DLC film 17 is formed. Further, it is preferable that the DLC film 17 is formed so that the tungsten component is contained more on the formation surface side than on the film surface side. That is, the end face 14 in which the tungsten component, which is a metal atom, is made of a metal material.
By grading the composition components of the DLC film 17 so that the DLC film 17 is abundant on the a and 14b sides, the end face 1 of the DLC film 17 is inclined.
This is because the adhesion strength to 4a and 14b can be easily improved.

Specifically, the DLC film 17 is made of DLC.
Similar to the film 16, a hard film having a film thickness of about 1.0 to 5.0 μm and a Vickers hardness of about 1000 to 2000 (Hv) is formed, and the axial end faces 12a2, 12b2 of the inner ring 12 are formed. Fretting wear between and is suppressed. The surface roughness of the DLC film 17 is controlled to, for example, a center line average roughness (Ra) of 0.1 μm or less, and a predetermined adhesion force (at least 40 N, preferably 60).
N) is joined to the end faces 14a and 14b.

Further, the DLC film 17 is formed by, for example, a sputtering method using tungsten carbide as a target in a vapor deposition chamber into which an argon gas or a hydrocarbon gas is introduced, or tungsten in a vapor deposition chamber into which a hydrocarbon gas is introduced. It is formed by using a sputtering method as a target, the pressure in the vapor deposition chamber is set to about 10 ⁻³ to 10 (Torr), and the discharge voltage is set to 10
A film is formed on the end faces 14a and 14b by performing a discharge process of 0 to 2000 (V) and a current of 2 to 10 (A). Incidentally, for example, when a film is formed by a sputtering method targeting tungsten carbide under an argon gas atmosphere, a tungsten carbide film is formed, and this tungsten carbide film is substantially the same as a diamond-like carbon film containing tungsten. Has become. Therefore, the DLC film 17 also includes the tungsten carbide film as described above. Also, DLC
By changing the amount of hydrocarbon gas or shielding the end faces 14a and 14b by a shutter during the film formation, the composition components of the DLC film 17 can be formed with a gradient. As with the DLC film 16, the DLC film 17 can be formed by using a physical vapor deposition method other than the sputtering method, a chemical vapor deposition method, or a thermal spraying method.

As described above, in this embodiment, the DLC film 17 and the end face 1 are made to contain tungsten.
Since it is possible to enhance the adhesion between the end surfaces 14a and 14b, the DLC film 17 can be firmly formed on the end surfaces 14a and 14b, and the DLC film 17 can be reliably prevented from peeling off from the end surfaces 14a and 14b. Can the DL
The durability of the C film 17 can be improved. Further, since the adhesion between the end faces 14a, 14b can be enhanced, the spacer end faces 14a, 1 can be formed by knurling or the like.
It is not necessary to finish 4b to a rough surface. Furthermore, the DLC film 1
Since 7 contains tungsten, the DLC film 17
Since the bearing has conductivity, it is possible to easily configure a bearing device suitable for the journal portion A1 and the like, which requires conductivity. DLC containing tungsten
The DLC film 16 containing no tungsten may be further formed on the film 17, and the DLC film 16 may be formed.
It is also possible to further form the DLC film 17 on the above and form the DLC film 16 thereon, that is, to stack the DLC films 16 and 17 sequentially. In this case, the adhesion is further increased. It is considered that the boundary is not formed at the boundary of each of these films, but is diffused and bonded to each other at the atomic level, so that the adhesion is improved.

FIG. 5 is an enlarged sectional view showing the structure of the main part of a bearing device of another embodiment. In the figure, in this embodiment, the DLC film 17 containing tungsten and the end faces 14a and 14b on which the DLC film 17 is formed are formed.
In between, a chromium film 18 was formed as a base film for enhancing the adhesion of the DLC film 17 to the end face. Specifically, for example, a chromium film 18 having a predetermined thickness is formed on the end faces 14a and 14b by a sputtering method using chromium as a target in an argon gas atmosphere, and then the chromium film 1 is formed.
DLC film 17 was formed on No. 8. Thus, the DLC film 17 is formed on the end surfaces 14a and 14b with the chromium film 18 interposed.
By forming the above, the DLC film 17 and the end face 14a,
The adhesiveness between the DLC film 1 and
7 can be firmly formed on the end faces 14a and 14b. Further, by interposing the chromium film 18, the DL
It is possible to more reliably prevent the peeling of the C film 17 from the end faces 14a and 14b, and further improve the durability of the DLC film 17. Moreover, since the adhesion between the end surfaces 14a and 14b can be enhanced, it is not necessary to finish the spacer end surfaces 14a and 14b into a rough surface by knurling or the like.

More specifically, in forming the chromium film 18, the pressure in the vapor deposition chamber into which the argon gas as the introduction gas is introduced is set to about 10 ⁻³ to 10 (Torr),
Discharge voltage 100-2000 (V), current 0.5-5
By performing the discharge treatment of (A), the spacer end surface 14
Chromium as a target is vapor-deposited on a and 14b,
A chromium film 18 having a film thickness of 0.4 to 0.6 μm is formed.
Then, by the same method as shown in FIG.
The film 17 is formed on the chromium film 18. However, this DLC
The film thickness of the film 17 is preferably about 1.5 to 3.0 μm in total with the chromium film 18 in order to prevent abrasion resistance and peeling due to internal stress.
It is preferable that the hardness is about Vickers hardness of 1000 to 2000 (Hv), and the surface roughness of the outermost surface DLC film 17 is 0.1 μm or less in terms of center line average roughness (Ra).

In the above embodiment, the structure using the chromium film 18 as the base film of the DLC film 17 has been described, but the present invention is not limited to this, and the titanium film may be used instead of the chromium film 18. A metal thin film made of an active transition metal such as can be used as a base film for the DLC films 16 and 17. Further, the base film is not limited to a single layer composed of one thin film, but may be a plurality of layers composed of a plurality of thin films composed of different components between the DLC films 16 and 17 and the formation surface. . However, the chromium film 18 was most suitable for improving the adhesion of the DLC film 17 containing tungsten.

For example, as shown in FIG. 6, a chromium film 18 and a tungsten carbide film, which are laminated on each other, are formed between the DLC film 16 and the respective end faces 14a, 14b on which the DLC film 16 is formed. May be. Specifically, for example, a chromium film 18 having a predetermined thickness is formed as a base film on the end surfaces 14a and 14b by, for example, a sputtering method, and then a tungsten carbide film having a predetermined thickness is formed as an intermediate layer 19 by a sputtering method. To do. Then, the DLC film 16 is formed on the intermediate layer 19. In this way, the chromium film 18 is formed from the end surfaces 14a and 14b.
By sequentially stacking the intermediate layer 19 and the intermediate layer 19, the adhesion between the end faces 14a and 14b and the DLC film 16 is enhanced without finishing the end faces 14a and 14b to a rough surface, as in the embodiment shown in FIG. The DLC film 16 can be firmly formed on the end surfaces 14a and 14b, and the DLC film 16 can be more reliably prevented from being peeled off from the end surfaces 14a and 14b to further improve the durability of the DLC film 16. Can be improved. Further, the chromium film 18 is formed on the end faces 14a and 14b made of a metal material, and the intermediate layer 19 containing the tungsten component and the carbon component is formed on the end faces 14a and 14b.
Since it is formed between the end surface 1 and the DLC film 16,
It is possible to form films having excellent adhesion between the 4a and 14b and the chrome film 18, between the chrome film 18 and the intermediate layer 19, and between the intermediate layer 19 and the DLC film 16. No boundary surface is formed at the boundary of each of these films,
It is considered that the above-mentioned adhesion is improved because the atoms are diffused and bonded to each other at the atomic level.
The DLC film 17 containing tungsten may be used as the intermediate layer 19, and the intermediate layer 19 has DLC and a metal component having good adhesiveness with the chromium film 18 as its composition component.
Any material containing a carbon component having good adhesion to the film 16 may be used. Also, the chromium film 18, the intermediate layer 19, and D
The total thickness of the LC film 16 is 1.5 to 3.0 in order to prevent abrasion resistance and peeling due to internal stress.
It is preferable to set the Vickers hardness to about 1000 to 2000 (Hv), and the surface roughness of the outermost DLC film 16 is the center line average roughness (R).
It is preferable that it is 0.1 μm or less in a).

In the above description, the DLC films 16 and 17 are
The case where the end faces 14a and 14b of the spacer 14 are formed has been described.
And the other end surface 1 of the spacer 14
4b and the axial end surface 1 of the other inner ring 12b that contacts this 4b
2b2, one of the end faces of the DLC film 16, 17
May be formed, and a DLC film may be formed only on the inner ring side, or a DLC film may be formed on one inner ring axial end face 12a2 and the other end face 14b of the spacer 14.

Further, in the above description, the pair of inner rings 12
Although the bearing device in which the spacer 14 is interposed between the a and 12b has been described, the bearing device of the present invention is not limited to this, and the inner rings 12a and 12b directly connect the spacer 14 without interposing the spacer 14 therebetween. Also, it can be applied to bearings that are butted in the axial direction. Specifically, as shown in FIG. 7, a pair of inner rings 12a abutted in the axial direction,
One of the end faces of 12b, for example, the inner ring 1
DLC on the axial end face (butt end face) 12a2 of 2a
The film 16 may be formed. As a result, one inner ring 12
a DLC film 16 formed on the axial end face 12a2 of a
Even if the axial end surface 12b2 of the other inner ring 12b and the axial end surface 12b2 repeatedly rub against each other under the influence of the bending of the axle A, fretting wear at the axial butting portion can be suppressed, and the spacer 14 It is possible to obtain the same effect as that of the above embodiment in which

In the above description, the double row tapered roller bearing 1 provided with the single outer ring 11 and the pair of inner rings 12a and 12b is applied to the bearing device which supports the axle A of the railway vehicle. Although the case has been described, the present invention is not limited to the type and number of bearings of the bearing device, the object to be supported, or the like. That is, the present invention is applied to a bearing device having a bearing in which at least one of an inner ring and an outer ring has a pair of bearing ring members arranged in parallel with their end faces abutting each other in a single row or a plurality of rows. A bearing device having a double row tapered roller bearing having a single inner ring integrally formed as a whole and a pair of axially divided outer rings, or a ball having a single inner and outer ring The present invention can be applied to axially abutting portions (contact portions of inner ring and outer ring of two adjacent ball bearings that contact each other) of a bearing device or the like in which a plurality of bearings are arranged side by side so as to be in contact with each other in the axial direction.

[0035]

The present invention constructed as described above has the following effects. According to the bearing device of the first and second aspects, the diamond-like carbon film suppresses fretting wear at the abutting portion in the axial direction, so that generation of metal wear powder due to the fretting wear can be suppressed as much as possible. . As a result, it is possible to prevent the lubricating oil from being contaminated by the metal abrasion powder, and thus to prevent the deterioration of the lubricating oil, and at the same time, the metal abrasion powder enters the rolling contact portion between the inner and outer races and the rolling elements, and the surface of the inner and outer races Also, it is possible to prevent the surface of the rolling element from being damaged. Therefore, it is possible to prevent the bearing life from being shortened.

According to the bearing device of the third aspect, since the diamond-like carbon film contains tungsten, the diamond-like carbon film and the end face on which the diamond-like carbon film is formed are closely attached. The diamond-like carbon film can be strongly formed on the end face thereof, the peeling of the diamond-like carbon film can be reliably prevented, and the durability of the diamond-like carbon film can be improved.

Further, according to the bearing device of the fourth aspect, since the chromium film is formed as a base film between the diamond-like carbon film and the end face on which the diamond-like carbon film is formed, the diamond-like carbon film is formed. The adhesion to the end surface of the carbon film can be enhanced, and the diamond-like carbon film can be firmly formed on the end surface, and the diamond-like carbon film can be more reliably prevented from peeling and the durability of the diamond-like carbon film can be improved. Can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an axle journal portion of a railway vehicle using a bearing device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main configuration of the bearing device shown in FIG.

FIG. 3 is a graph showing test results conducted by the inventors of the present invention, (a) is a graph showing verification results of aggressiveness of various coatings on a contact surface, and (b) is friction of various coatings. It is a graph which shows the verification result of a coefficient.

FIG. 4 is an enlarged cross-sectional view showing the main configuration of a bearing device according to another embodiment.

FIG. 5 is an enlarged cross-sectional view showing the main configuration of a bearing device of another embodiment.

FIG. 6 is an enlarged cross-sectional view showing the main configuration of a bearing device according to another embodiment.

FIG. 7 is an enlarged cross-sectional view showing the main configuration of a bearing device according to another embodiment.

FIG. 8 is a sectional view showing an axle journal portion of a railway vehicle using a conventional bearing device.

[Explanation of symbols]

1 Double row tapered roller bearing 11 outer ring 12a, 12b Inner ring (race ring member) 12a2, 12b2 Axial end face (butt end face) 13a, 13b Tapered rollers (rolling elements) 14 Zama 14a, 14b end faces 16,17 Diamond-like carbon (DLC) film 18 Chromium film (base film) 19 Middle class

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J101 AA16 AA25 AA32 AA43 AA54                       AA62 BA53 BA54 BA57 BA70                       DA05 FA35 GA01

Claims (4)

[Claims] 1. A bearing device comprising a bearing having an inner ring and an outer ring, and a rolling element rotatably arranged between the inner ring and the outer ring, wherein at least one race ring of the inner ring and the outer ring comprises: A pair of raceway members arranged in parallel with their end faces butted against each other are arranged in a single row or a plurality of rows, and a diamond-like carbon film is formed on either one of the butted end faces of the pair of raceway members. Bearing device characterized by the above. 2. A bearing device comprising a bearing having an inner ring and an outer ring and a rolling element rotatably arranged between the inner ring and the outer ring, wherein at least one of the inner ring and the outer ring is a race ring. A pair of orbital ring members arranged in parallel with the spacer in between are arranged in a single row or a plurality of rows, and one of the end faces of the spacer and one of the end faces of the orbital ring members in contact therewith, and A bearing device characterized in that a diamond-like carbon film is formed on either one of the other end surface of the spacer and the end surface of the bearing ring member in contact therewith. 3. The bearing device according to claim 1, wherein the diamond-like carbon film contains tungsten. 4. A chromium film is formed between the diamond-like carbon film and an end face on which the diamond-like carbon film is formed.
The bearing device according to any one of 1.