WO2007043298A1

WO2007043298A1 - Anti-electrolytic corrosion rolling bearing

Info

Publication number: WO2007043298A1
Application number: PCT/JP2006/318714
Authority: WO
Inventors: Naoaki Tsuji; Hideji Ito
Original assignee: Ntn Corporation
Priority date: 2005-10-07
Filing date: 2006-09-21
Publication date: 2007-04-19
Also published as: JP2007100914A

Abstract

An anti-electrolytic corrosion rolling bearing in which a thermal sprayed film of a ceramic can be prevented from being damaged when it is press-fitted in a housing or press-fitted over a shaft. A chamfered portion (1c) is provided between the inside diameter surface (1a) and the end plane (1b) of an inner ring (1) and a thermal sprayed film (4) of a ceramic serving as an insulation layer is provided from the inside diameter surface (1a) over the end plane (1b). A part (4a) of the inside diameter surface (1a) and a part (4c) of the chamfered portion (1c) on the surface of the thermal sprayed film (4) are subjected to smoothing such as polishing and the surface of the boundary (4ac) between the inside diameter surface (1a) and the chamfered portion (1c) is made smooth.

Description

Specification

Anti-corrosion rolling bearing

Technical field

[0001] The present invention includes general-purpose motors, generators for generators, main motors for railway vehicles, etc.

Furthermore, the present invention relates to an electric corrosion-preventing rolling bearing that is used in applications where it is necessary to prevent a current from flowing inside the bearing due to the structure of the device in which the bearing is incorporated.

Background art

[0002] As this type of electrolytic corrosion-preventing rolling bearing, for example, a ceramic thermal spray coating serving as an insulating layer over the outer diameter surface and the width surface of the outer ring is known (for example, Patent Document 1). In the electric corrosion-preventing rolling bearing having such a structure, dimensional accuracy is ensured by polishing each part of the outer ring outer diameter surface and outer ring width surface on the surface of the spray coating after the formation of the spray coating.

Patent Document 1: JP-A-2002-48145

[0003] In the electrolytic corrosion-preventing rolling bearing having the above structure, in the polishing process after the formation of the sprayed coating, the chamfered portion between the outer ring outer diameter surface and the outer ring width surface on the surface of the sprayed coating is not subjected to polishing calecities. It remains in the surface state after spraying.

In the case of a normal bearing, when it is incorporated into another member such as a shaft or a housing, it is guided by a chamfered portion and can be smoothly incorporated into a mating surface. The connection between the outer diameter surface and the chamfered portion is smooth and can be inserted without causing kinking when inserted into the shaft and the nosing.

However, in the case of a bearing with a ceramic spray coating, if the chamfered part is not processed as described above, when the bearing is pressed in the axial direction into the nose, the ceramics will be damaged. The inner surface of the housing, which is a material, is scraped off. For this reason, as the amount of movement of the bearing in the press-fitting direction increases, the fitting becomes tight due to the biting of the abrasion powder of the housing, and eventually the ceramic spray coating is damaged. Such a problem also occurs in the case of an electroerosion-proof rolling bearing having a ceramic spray coating over the inner diameter surface and the width surface of the inner ring at the time of press-fitting to the shaft. Disclosure of the invention

[0004] An object of the present invention is to provide an electric corrosion-preventing rolling bearing capable of preventing a ceramic sprayed coating from being damaged during press-fitting to a housing or a shaft.

[0005] The electrolytic corrosion-preventing rolling bearing according to the first configuration of the present invention is provided with a chamfered portion between the inner diameter surface and the width surface of the inner ring, and thermal spraying of ceramics serving as an insulating layer from the inner diameter surface to the width surface. An electric corrosion-preventing rolling bearing provided with a coating, wherein a portion corresponding to the inner ring inner diameter surface on the surface of the thermal spray coating and a portion corresponding to at least a boundary with the inner ring inner diameter surface in the chamfered portion are smoothed. Give it. The smoothing process is a process of smoothing the surface, for example, a polishing cache. Smoothing may be applied to the entire chamfered portion.

According to this configuration, the inner ring inner diameter surface portion on the surface of the ceramic sprayed coating and the boundary between the chamfered portion and at least the inner ring inner diameter surface are smoothed. Even if guided by the part, the inner ring inner diameter surface is smoothly guided to the shaft outer diameter surface, which is a mating surface where the mating material cannot be cut by the ceramic spray coating. For this reason, it is possible to press fit into a shaft that does not damage the ceramic sprayed coating that does not cause twisting.

[0006] The electrolytic corrosion-preventing rolling bearing according to the second configuration of the present invention is provided with a chamfered portion between the outer diameter surface and the width surface of the outer ring, and the ceramic serving as an insulating layer from the outer diameter surface to the width surface. An electro-corrosion-preventing rolling bearing provided with a thermal spray coating of: a portion corresponding to the outer ring outer diameter surface on the surface of the thermal spray coating, and a portion corresponding to a boundary between at least the outer ring outer diameter surface of the chamfered portion. Smoothing is applied. Smoothing may be applied to the entire chamfered portion.

According to this configuration, the outer ring outer diameter surface portion on the surface of the ceramic sprayed coating and the boundary between at least the outer ring outer diameter surface in the chamfered portion are subjected to a smoothing force, so the outer ring is applied to the housing. The outer ring outer diameter surface is smoothly guided to the inner diameter surface of the housing, which is a fitting surface where the mating material cannot be cut by the ceramic spray coating, even if it is guided by the chamfered portion. Therefore, it can be press-fitted into the housing without damaging the ceramic sprayed coating that does not cause twisting. [0007] In the first configuration, the chamfering angle of the boundary portion between the inner diameter surface and the chamfered portion of the metal base material of the inner ring may be 12 ° or less. When the chamfering angle of the boundary portion is 12 ° or less, press-fitting to the shaft can be performed more smoothly, and damage to the ceramic sprayed coating due to press-fitting can be more reliably prevented.

[0008] In the second configuration, the chamfering angle of the boundary portion between the outer diameter surface and the chamfered portion of the metal base material of the outer ring may be 12 ° or less. When the chamfer angle at the boundary is 12 ° or less, the press-fitting to the housing can be performed more smoothly, and it is possible to more reliably prevent the ceramic spray coating from being damaged due to the press-fitting.

Brief Description of Drawings

[0009] The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings, in which: However, the examples and drawings are for illustration and description only and should not be used to define the scope of the invention. The scope of the invention is determined by the appended claims. In the accompanying drawings, the same part number in a plurality of drawings indicates the same part.

FIG. 1 is a partial cross-sectional view of an electrolytic corrosion-preventing rolling bearing according to an embodiment of the present invention.

[Fig. 2] (A) is an enlarged view when the inner ring chamfered portion of the sprayed coating surface in part A of Fig. 1 is not smoothed, and (B) is an enlarged view when the inner ring chamfered portion is smoothed. .

FIG. 3 is an explanatory diagram of a chamfer angle in a metal base material of an inner ring.

FIG. 4 is a partial cross-sectional view of an electric corrosion prevention rolling bearing according to another embodiment of the present invention.

[Fig. 5] (A) is an enlarged view when the outer ring chamfered portion of the sprayed coating surface in part B of Fig. 4 is not smoothed, and (B) is an enlarged view when the outer ring chamfered portion is smoothed. is there.

FIG. 6 is an explanatory diagram of a chamfer angle in a metal base material of an outer ring.

BEST MODE FOR CARRYING OUT THE INVENTION

One embodiment of the present invention will be described with reference to FIGS. 1 to 3. This electric corrosion-preventing rolling bearing has an inner ring that serves as a fitting surface to be fitted to another member such as a shaft body in which a rolling element 3 is interposed between an inner ring 1 and an outer ring 2 that are raceways. A ceramic spray coating 4 serving as an insulating layer is provided over the inner diameter surface la, the width surface lb, and the chamfered portion lc provided between the inner diameter surface la and the width surface lb. This bearing is used, for example, in the main motor of a railway vehicle. It is used for a bearing for supporting a rotor which is a shaft body. This bearing is a cylindrical roller bearing, and the outer ring 2 has flanges 2A on both sides. The rolling element 3 may be held in a pocket of a cage (not shown), or the cage may be omitted as a full roller bearing in which the rollers are arranged without a gap in the circumferential direction. The inner and outer rings 1, 2 and the rolling elements 3 are made of a metal material such as bearing steel.

[0011] Ceramic materials for thermal spray coating 4 include white alumina (Al 2 O 3) and gray aluminum

twenty three

Na (Al 2 O 3 +) or the like is used.

2 3 2

After the formation of the thermal spray coating 4, the portion 4a corresponding to the inner ring inner surface la on the surface of the thermal spray coating 4 and the portion 4b corresponding to the inner ring width surface lb are subjected to a smoothing process to ensure dimensional accuracy. The The portion 4c corresponding to the inner ring chamfered portion lc is also smoothed. Here, the polishing force is applied as the smoothing process.

[0012] Part A of Fig. 1 is enlarged and shown in Fig. 2 (B). FIG. 2A is a comparative example. In this embodiment, as shown in FIG. 5B, the portion 4c corresponding to the inner ring chamfered portion lc is also smoothed, so that the portion 4a corresponding to the inner ring inner surface la and the inner ring chamfered portion lc The surface of the boundary 4ac between the corresponding part 4c and the surface becomes smooth!

In the comparative example of FIG. 5A, the surface of the thermal spray coating 4 is smoothed only on the portion 4a corresponding to the inner ring inner surface la and the portion 4b corresponding to the inner ring width surface lb, and corresponds to the inner ring chamfered portion lc. This is the case where the part 4c to be processed is not processed. In this case, the boundary 4ac between the portion 4a corresponding to the inner ring inner surface la and the portion 4c corresponding to the inner ring chamfered portion lc is rough.

Further, in this embodiment, before forming the sprayed coating 4, as shown in an enlarged view in FIG. 3, the fitting of the boundary portion lac between the inner diameter surface la and the chamfered portion lc in the metal base material of the inner ring 1 is performed. Mating surface (outer diameter surface of shaft) Chamfering angle with respect to S1 0 1 is 12 ° or less.

[0014] According to this configuration, the thermal spray coating 4 of ceramic serving as an insulating layer is interposed between the inner ring 1 and the shaft, so that insulation is ensured between them, and the housing and shaft fitted to the outer ring 2 are secured. Electrical insulation is ensured.

As shown in FIG. 2 (B), the ceramic sprayed coating 4 has a portion 4a corresponding to the inner ring inner diameter surface la on the surface of the sprayed coating 4, and a portion 4c corresponding to the inner ring chamfered portion lc. Since the surface of the boundary 4ac is smoothed by the smoothing process, even if it is guided by the inner ring chamfered part lc when it is press-fitted to the shaft (not shown), the ceramic sprayed coating 4 The inner ring inner diameter surface la is smoothly guided to the shaft outer diameter surface, which is the fitting surface, at the boundary 4ac where the shaft, which is the material, cannot be cut. Therefore, it is possible to press-fit into the shaft without damaging the sprayed coating 4 which does not cause twisting.

[0015] Further, in this embodiment, the chamfering angle θ1 of the boundary portion lac between the inner diameter surface la and the chamfered portion lc of the metal base material of the inner ring 1 is set to 12 ° or less. This can be performed more smoothly, and the sprayed coating 4 can be more reliably prevented from being damaged due to press fitting.

[0016] Table 1 shows the test results for examining the relationship between the chamfering angle θ 1 and the presence or absence of twisting. The test bearing is the bearing shown in Fig. 1 with an inner diameter of φ80mm. As shown in Table 1, when the chamfer angle θ 1 exceeds 12 °, twisting occurs, and when it reaches 14 °, twisting occurs frequently. When the chamfering angle 0 1 was 12 ° or less, no twisting was observed. The chamfer angle 0 1 is preferably 9 ° or more in order to exhibit the guide function of the inner ring chamfered portion lc.

[0017] [Table 1]

○: No twisting △: Twisting X: Many twists

Another embodiment of the present invention is shown in FIGS. This electric corrosion-preventing rolling bearing is a fitting in which the outer ring 2 which is a raceway ring is fitted to another member such as a housing instead of the sprayed coating 4 provided on the inner ring 1 in the embodiment of FIG. A ceramic sprayed coating 5 serving as an insulating layer is provided over the outer diameter surface 2a, the width surface 2b, and the chamfered portion 2c formed between the outer diameter surface 2a and the width surface 2b. In this case, after the thermal spray coating 5 is formed, a smoothing process for ensuring dimensional accuracy is performed on the portion 5a corresponding to the outer ring outer diameter surface 2a and the portion 5b corresponding to the outer ring width surface 2b on the surface of the thermal spray coating 5. Is done. The portion 5c corresponding to the outer ring chamfered portion 2c is also smoothed. In this case as well, the polishing force is applied as a smoothing process. [0019] Part B of FIG. 4 is enlarged and shown in FIG. As shown in the figure, the portion 5c corresponding to the outer ring chamfered portion 2c is also smoothed, and the boundary 5ac between the portion 5a corresponding to the outer ring outer diameter surface 2a and the portion 5c corresponding to the outer ring chamfered portion 2c The surface is smooth.

Figure 5 (A) is a comparative example. In this example, only the portion 5a corresponding to the outer ring outer diameter surface 2a and the portion 5b corresponding to the outer ring width surface 2b on the surface of the thermal spray coating 5 are smoothed, and the portion 5c corresponding to the outer ring chamfered portion 2c is not processed. This is the case. In this case, the boundary 5ac between the portion 5a corresponding to the outer ring outer diameter surface 2a and the portion 5c corresponding to the outer ring chamfered portion 2c is rough.

[0020] In this embodiment, before the formation of the thermal spray coating 5, as shown in an enlarged view in FIG. 6, the boundary portion 2ac between the outer diameter surface 2a and the chamfered portion 2c in the metal base material of the outer ring 2 is formed. The chamfering angle Θ2 with respect to the mating surface (inner diameter surface of the nosing and ousing) S2 is 12 ° or less. The chamfer angle Θ 2 is preferably 9 ° or more. Other configurations are the same as in the previous embodiment.

[0021] According to this configuration, since the ceramic sprayed coating 5 serving as an insulating layer is interposed between the outer ring 2 and the housing, insulation is ensured between the outer ring 2 and the housing. Electrical insulation is ensured.

It has a ceramic sprayed coating 5 but it corresponds to the outer ring outer diameter surface 2a portion 5a and the outer ring chamfered portion 2c on the surface of the outer ring 2 sprayed coating 5 as shown in FIG. 5 (B). Since the part 5c is smoothed and the surface of the boundary 5ac is smooth, even if it is guided by the outer ring chamfer 2c when it is press-fitted to the nose, the counterpart is covered by the ceramic spray coating 5 It is smoothly planned at the boundary 5ac where it is not necessary to cut the housing. Therefore, it is possible to press-fit into the know-how without damaging the sprayed coating 5 that does not cause twisting.

[0022] In this embodiment, the chamfering angle Θ2 of the boundary 2ac between the outer diameter surface 2a and the chamfered portion 2c of the metal base material of the outer ring 1 is set to 12 ° or less. It can be performed more smoothly, and the sprayed coating 5 can be more reliably prevented from being damaged due to press fitting.

[0023] In each of the above embodiments, the ceramic sprayed coatings 4, 5 have a force that is smoothened over the entire portions 4c, 5c corresponding to the chamfered portions lc, 2c of the inner ring 1 or the outer ring 2. Boundary 4ac , Only 5ac may be smoothed.

As described above, the preferred embodiments have been described with reference to the drawings. However, those skilled in the art will readily consider various changes and modifications within the obvious scope by looking at the present specification.

Accordingly, such changes and modifications are to be construed as within the scope of the invention, which also defines the power of the claims.

Claims

The scope of the claims

[1] An electrolytic corrosion-preventing rolling bearing having a chamfered portion between an inner diameter surface and a width surface of an inner ring, and a ceramic sprayed coating serving as an insulating layer from the inner diameter surface to the width surface. An electrolytic corrosion-preventing rolling bearing in which a portion corresponding to the inner ring inner surface on the surface of the coating and a portion corresponding to the boundary with the inner ring inner surface on at least the chamfered portion are smoothed.

[2] An electrolytic corrosion-preventing rolling bearing having a chamfered portion between an outer diameter surface and a width surface of an outer ring, and a ceramic sprayed coating serving as an insulating layer from the outer diameter surface to the width surface, An electrolytic corrosion-preventing rolling bearing in which a portion corresponding to the outer ring outer diameter surface on the surface of the thermal spray coating and a portion corresponding to a boundary between the outer ring outer diameter surface and at least the chamfered portion are smoothed.

[3] The electrolytic corrosion-preventing rolling bearing according to claim 1, wherein a chamfering angle of a boundary portion between the inner diameter surface and the chamfered portion of the metal base material of the inner ring is 12 ° or less.

[4] The electrolytic corrosion-preventing rolling bearing according to claim 3, wherein the chamfer angle is 9 ° or more.

[5] The electrolytic corrosion-preventing rolling bearing according to claim 2, wherein a chamfering angle of a boundary portion between the outer diameter surface and the chamfered portion of the metal base material of the outer ring is 12 ° or less.

[6] The electrolytic corrosion-preventing rolling bearing according to claim 5, wherein the chamfer angle is 9 ° or more.