Bearing seal

Abstract

To secure conductivity and to prevent increase in manufacturing cost without technical difficulty in manufacturing, with respect to a bearing seal for preventing electric corrosion of a rolling bearing.SOLUTION: A bearing seal includes: annular first metal plate 2A and second metal plate 2B; and a conductive material 3 held by the first metal plate 2A and the second metal plate 2B. One or both of the first metal plate 2A and the second metal plate 2B are kept into contact with an outer ring. The conductive material 3 is composed of annular felt 4 having conductivity. The annular felt 4 has an extension portion 6 extending from an inner end 5 in a radial direction R of the first metal plate 2A and the second metal plate 2B to an inner part RI in the radial direction R. An inner peripheral surface 4A of the annular felt 4 is kept into contact with an inner ring 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bearing seal that prevents electrolytic corrosion of a rolling bearing. [Background technology]

[0002] For example, electric current may leak and flow to a rotating shaft in motors and reduction gear units of electric vehicles, and inverter-driven motors other than those of electric vehicles. In such cases, in the rolling bearings supporting the rotating shaft, a current may break through the lubricating oil film and flow between the inner and outer rings, causing damage to the rolling surfaces of the rolling elements due to arcing.

[0003] One bearing seal for preventing electrical corrosion in such rolling bearings consists of an annular sealing plate fixed to the seal groove of the outer ring of the rolling bearing, and an electrically conductive, annular sliding member attached to the sealing plate and in sliding contact with the outer periphery of the inner ring of the rolling bearing (see, for example, Patent Document 1).

[0004] The sealing plate is an annular member made of two metal plates that sandwich and support the sliding member. The sliding member is a plain weave fabric in which conductive fibers and low-friction fibers are woven, and is therefore conductive. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-106971 A Summary of the Invention [Problem to be solved by the invention]

[0006] When a plain-woven sliding member having a structure as described in Patent Document 1 is used, the sliding member has a surface that does not exhibit conductivity because it is a combination of conductive fibers and non-conductive fibers. Therefore, there are cases where conductivity cannot be ensured.

[0007] As in Patent Document 1, combining two types of fibers, conductive fibers and low-friction fibers, into a plain weave fabric to obtain the required conductivity and low friction is technically difficult, and therefore increases the manufacturing cost.

[0008] An object of the present invention is to provide a bearing seal for preventing electrolytic corrosion of a rolling bearing, which can ensure electrical conductivity, can be manufactured without technical difficulties, and does not increase manufacturing costs. [Means for solving the problem]

[0009] In order to solve the above problems, the bearing seal according to the present invention is a bearing seal used in a rolling bearing including an outer ring, an inner ring, and rolling elements, and includes annular first and second metal plates, and a conductive material sandwiched between the first and second metal plates. One or both of the first and second metal plates, or a conductive rubber covering the radially outer parts of the first and second metal plates and extending radially outward, contacts the outer ring. The conductive material is annular felt having electrical conductivity. The annular felt has an extension portion extending radially inward from the radially inner ends of the first and second metal plates, and the inner circumferential surface of the annular felt contacts the inner ring.

[0010] In order to solve the above problems, the bearing seal according to the present invention is a bearing seal used in a rolling bearing including an outer ring, an inner ring, and rolling elements, and includes annular first and second metal plates, and a conductive material sandwiched between the first and second metal plates. One or both of the first and second metal plates, or a conductive rubber covering the radially inner parts of the first and second metal plates and extending radially inward, contacts the inner ring. The conductive material is annular felt having electrical conductivity. The annular felt has an extension portion extending radially outward from the radially outer ends of the first and second metal plates, and the outer circumferential surface of the annular felt contacts the outer ring.

[0011] With these bearing seal configurations, the conductive material sandwiched between the first and second metal plates is conductive annular felt, and the inner or outer circumferential surface of the annular felt slides on the inner ring or outer ring. Therefore, the annular felt, which is a sliding member that slides on the inner ring or outer ring, is conductive no matter where it comes into contact with the inner ring or outer ring, ensuring conductivity.

[0012] In addition, the conductive material is felt, which is made by entangling conductive fibers, so there is no need for weaving, and there is no technical difficulty in manufacturing, making it easy to manufacture, and therefore the manufacturing cost does not increase.

[0013] Furthermore, when the outer and inner surfaces of the extension of the annular felt in the width direction of the rolling bearing are exposed, the extension also functions as a normal felt seal, and has a filtering effect that prevents foreign matter from entering the inside of the bearing in the oil.

[0014] In a preferred embodiment, radially extending rubber pieces are attached to the extending portions of the annular felt, and the rubber pieces are spaced apart in the circumferential direction at substantially equal intervals.

[0015] With this type of bearing seal configuration, the elasticity of the rubber pieces attached to the extensions of the conductive annular felt increases the reaction force against the sliding surface, ensuring long-term conductivity. Furthermore, since the felt is exposed between adjacent rubber pieces in the circumferential direction, the performance as a felt seal can be maintained.

[0016] In another preferred embodiment, a rubber film is attached to the extension of the annular felt so as to cover substantially the entire surface of the extension.

[0017] With this type of bearing seal configuration, the elasticity of the rubber film attached to almost the entire surface of the extended portion of the conductive annular felt applies a uniform reaction force to the sliding surface, further increasing the reaction force against the sliding surface, thereby ensuring a more stable conductivity over a long period of time.

[0018] In another preferred embodiment, a seal lip is provided on the inner side of the extension of the annular felt in the width direction of the rolling bearing, the seal lip extending away from the extension and coming into contact with the inner ring or the outer ring.

[0019] According to this bearing seal configuration, the provision of a seal lip that contacts the inner ring or the outer ring improves the sealing performance of the rolling bearing, and is therefore suitable as an embodiment when the rolling bearing is of the grease-filled type. Effect of the Invention

[0020] As described above, with the bearing seal of the present invention, the inner or outer circumferential surface of the conductive annular felt slides on the inner or outer ring. Therefore, no matter where on the inner or outer circumferential surface of the sliding member sliding on the inner or outer ring it comes into contact with the inner or outer ring, it is conductive, so conductivity can be stably and reliably ensured. Furthermore, because the conductive material is felt, no weaving is required, and there are no technical difficulties in manufacturing, making it easy to manufacture, so manufacturing costs do not increase. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a partially sectional perspective view of a rolling bearing according to an embodiment of the present invention, showing an example in which a first metal plate contacts the outer ring, and the inner circumferential surface of an annular conductive felt contacts the inner ring. [Diagram 2] FIG. 2 is an enlarged longitudinal sectional view of a main portion of the rolling bearing of FIG. [Diagram 3] FIG. 2 is a view of the rolling bearing in FIG. 1 as viewed from the direction of the central axis of rotation. [Figure 4] This is an enlarged longitudinal cross-sectional view of a key portion of a rolling bearing according to an embodiment of the present invention, showing an example in which the inner ring with which the inner surface of the conductive annular felt comes into contact does not have a cylindrical surface as the outer circumferential surface in the width direction, but is an inclined surface that approaches radially outward as it moves inward in the width direction. [Diagram 5]FIG. 1 is a partial cross-sectional oblique view of a rolling bearing according to an embodiment of the present invention, showing an example in which conductive rubber covering the radially outer portions of the first metal plate and the second metal plate and extending radially outward contacts the outer ring, and the inner surface of a conductive annular felt contacts the inner ring. [Figure 6] FIG. 6 is an enlarged longitudinal sectional view of a main portion of the rolling bearing of FIG. 5. [Figure 7] 6 is a view of the rolling bearing in FIG. 5 as viewed from the direction of the central axis of rotation. [Figure 8] FIG. 6 is a partial cross-sectional perspective view of a rolling bearing according to an embodiment of the present invention, showing an example in which a radially extending rubber piece is attached to the extension of the annular felt, which is a conductive material, in the rolling bearing of FIG. 5. [Figure 9] FIG. 9 is an enlarged longitudinal sectional view of a main portion of the rolling bearing of FIG. 8. [Figure 10] 9 is a view of the rolling bearing in FIG. 8 as viewed from the direction of the central axis of rotation. [Figure 11] FIG. 6 is a partial cross-sectional oblique view of a rolling bearing according to an embodiment of the present invention, showing an example in which a rubber film is attached to the extension of the annular felt, which is a conductive material, in the rolling bearing of FIG. 5, covering almost the entire surface of the extension. [Figure 12] 12 is an enlarged longitudinal sectional view of a main portion of the rolling bearing of FIG. 11. [Figure 13] 12 is a view of the rolling bearing in FIG. 11 as viewed from the direction of the central axis of rotation. [Figure 14] FIG. 6 is a partial sectional oblique view of a rolling bearing according to an embodiment of the present invention, showing an example in which a seal lip is provided inward in the width direction of the rolling bearing of the extension portion of the annular felt, which is a conductive material, and extends away from the extension portion to contact the inner ring. [Figure 15] FIG. 15 is an enlarged longitudinal sectional view of a main portion of the rolling bearing of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] In this specification, the direction parallel to the direction of the central axis of rotation (see, for example, symbol O in Figs. 1 and 3) of the rolling bearing is called the "width direction" (see, for example, arrow B in Figs. 1 and 2), and the direction perpendicular to the direction of the central axis of rotation is called the "radial direction" (see, for example, arrow R in Figs. 2 and 3). The "circumferential direction" (see, for example, arrow C in Figs. 1 and 3) is defined with respect to the direction of the central axis of rotation.

[0024] In this specification, the width direction approaching the widthwise center of the rolling bearing (e.g., symbol D in Figure 2) is referred to as the "widthwise inward" (see, for example, arrow BI in Figure 2), the width direction moving away from the widthwise center is referred to as the "widthwise outward" (see, for example, arrow BO in Figure 2), the radial direction approaching the central axis of rotation is referred to as the "radial inward" (see, for example, arrow RI in Figure 2), and the radial direction moving away from the central axis of rotation is referred to as the "radial outward" (see, for example, arrow RO in Figure 2).

[0025] [Rolling bearings] 1 to 15 includes an outer ring 11, an inner ring 12, rolling elements 13, a cage 14, and a bearing seal 1. The rolling elements 13 roll between the raceway surface of the outer ring 11 and the raceway surface of the inner ring 12. The cage 14 guides the rolling elements 13 at a predetermined interval and holds them rotatably.

[0026] [Bearing seal] 1 to 15 comprises annular first and second metal plates 2A and 2B, and a conductive material 3 sandwiched between the first and second metal plates 2A and 2B. The conductive material 3 is annular felt 4 having electrical conductivity. The annular felt 4 has an extension portion 6 that extends inward RI in the radial direction R from an inner end 5 in the radial direction R of the first and second metal plates 2A and 2B, and an inner circumferential surface 4A of the annular felt 4 comes into contact with an inner ring 12.

[0027] The conductive annular felt 4 is formed by entangling conductive fibers. Carbon fibers or metal-coated chemical fibers are used as the conductive fibers. Copper, silver, and / or nickel are used as the metals that coat the chemical fibers. Carbon fibers can also be reinforced by mixing them with polyester resin or polyvinyl chloride resin.

[0028] 1 to 4, the first metal plate 2A enters the locking groove 11A of the outer ring 11, and the first metal plate 2A comes into contact with the outer ring 11. One or both of the first metal plate 2A and the second metal plate 2B may be brought into contact with the outer ring 11. In the bearing seal 1 shown in Figures 5 to 15, the conductive rubber 7 covering the outer RO parts of the first metal plate 2A and the second metal plate 2B in the radial direction R and extending outward RO in the radial direction R enters the locking groove 11A of the outer ring 11, and the conductive rubber 7 comes into contact with the outer ring 11.

[0029] The conductive rubber 7 is made of conductive nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), acrylic rubber (ACM), silicone rubber (VQM), fluororubber (FKM), ethylene propylene diene rubber (EPDM), or the like.

[0030] The bearing seal 1 shown in Figures 8 to 10 has rubber pieces 8 extending in the radial direction R attached to the surface of the extension portion 6 of the annular felt 4, on the outer BO side in the width direction B of the rolling bearing A, and the rubber pieces 8 are arranged at approximately equal intervals in the circumferential direction C.

[0031] According to the configuration of the bearing seal 1 shown in Figures 8 to 10, the reaction force against the sliding surface is increased by the elasticity of the rubber piece 8 attached to the extension portion 6 of the conductive annular felt 4, so that conductivity can be maintained for a long period of time.

[0032] The bearing seal 1 shown in Figures 11 to 13 has a rubber film 9 attached to the surface of the extension 6 of the annular felt 4 on the outer side BO in the width direction B of the rolling bearing A, covering almost the entire surface.

[0033] 11 to 13, the rubber film 9 attached to almost the entire surface of the extension 6 of the conductive annular felt 4 exerts a uniform reaction force on the sliding surface, and the reaction force on the sliding surface is further increased by the elasticity of the rubber film 9. Therefore, the conductivity can be more stably secured for a long period of time.

[0034] The bearing seal 1 shown in Figures 14 and 15 has a seal lip 10 that extends away from the extension 6 of the annular felt 4 on the inward side BI in the width direction B of the rolling bearing A and contacts the inner ring 12.

[0035] 14 and 15, the seal lip 10 that contacts the inner ring 12 is provided, improving the sealing performance of the rolling bearing A. Therefore, this is a suitable embodiment when the rolling bearing A is a grease-filled type.

[0036] 1 to 15, in the examples shown in Fig. 2, Fig. 6, Fig. 9, Fig. 12 and Fig. 15, the inner peripheral surface 4A of the annular felt 4, which is the conductive material 3, is in contact with the cylindrical surface, which is the outer peripheral surface in the width direction B of the inner ring 12. The present invention is not limited to such a configuration. For example, as shown in Fig. 4, the inner peripheral surface 4A of the annular felt 4, which is the conductive material 3, may be in contact with an inclined surface of the inner ring 12 that approaches the radially outward RO as it moves inward in the width direction BI.

[0037] 1 to 15 is an inner ring sliding type in which the inner peripheral surface 4A of the annular felt 4 slides on the outer peripheral surface of the inner ring 12. The present invention is not limited to this configuration, and may be an outer ring sliding type.

[0038] In the case of the outer ring sliding type, one or both of the first metal plate 2A and the second metal plate, or conductive rubber covering the inward RI in the radial direction R of the first metal plate 2A and the second metal plate 2B, and extending inward RI in the radial direction R, contacts the inner ring 12. The annular felt 4, which is the conductive material 3 sandwiched between the first metal plate 2A and the second metal plate 2B, has an extension portion that extends outward RO in the radial direction R from the outer end of the first metal plate 2A and the second metal plate 2B in the radial direction R, and the outer circumferential surface of the annular felt 4 contacts the outer ring 11. In this case, the seal lip as shown in Figures 14 and 15 extends away from the extension portion and contacts the outer ring 11.

[0039] [Effects] According to the configuration of the bearing seal 1 according to an embodiment of the present invention, the conductive material 3 sandwiched between the first metal plate 2A and the second metal plate 2B is annular felt 4 having electrical conductivity, and the inner circumferential surface 4A or the outer circumferential surface of the annular felt 4 slides on the inner ring 12 or the outer ring 11. Therefore, the annular felt 4, which is a sliding member that slides on the inner ring 12 or the outer ring 11, is conductive no matter where it comes into contact with the inner ring 12 or the outer ring 11, so conductivity can be ensured.

[0040] Moreover, the conductive material 3 is felt, which is formed by entangling conductive fibers themselves. Therefore, weaving is not required, and there is no technical difficulty in manufacturing, making it easy to manufacture, and therefore the manufacturing cost does not increase.

[0041] Furthermore, when the outer surface BO and the inner surface BI of the extension portion 6 of the annular felt 4 in the width direction B of the rolling bearing A are exposed, the extension portion 6 also functions as a normal felt seal, and has a filtering effect that prevents foreign matter from entering the inside of the bearing in the oil.

[0042] The above description of the embodiments is given by way of example only and is not intended to be limiting, and various improvements and modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0043] 1 Bearing seal 2A 1st metal plate 2B 2nd metal plate 3. Conductive materials 4. Circular felt 4A Inner surface 5 Radial inner end 6 Extension 7 Conductive Rubber 8 Rubber Pieces 9 Rubber membrane 10 Sealing Lip 11 Outer ring 11A Locking groove 12 Inner Circle 13 Rolling elements 14 Cage A Rolling bearing B direction BI Insider BO Foreign C Circumferential direction D width direction center R radial direction RI Inner Square RO Foreign

Claims

1. A bearing seal for use in a rolling bearing including an outer ring, an inner ring, and rolling elements, comprising: A first metal plate and a second metal plate each having an annular shape; a conductive material sandwiched between the first metal plate and the second metal plate; Equipped with One or both of the first metal plate and the second metal plate, or A conductive rubber covering the radially outer portions of the first metal plate and the second metal plate and extending radially outward, contacting the outer ring, The conductive material is a circular conductive felt. The annular felt has an extension portion extending radially inward from radially inner ends of the first metal plate and the second metal plate, The inner circumferential surface of the annular felt contacts the inner ring. Bearing seal.

2. A bearing seal for use in a rolling bearing including an outer ring, an inner ring, and rolling elements, comprising: A first metal plate and a second metal plate each having an annular shape; a conductive material sandwiched between the first metal plate and the second metal plate; Equipped with One or both of the first metal plate and the second metal plate, or A conductive rubber covering the radially inner portions of the first metal plate and the second metal plate and extending radially inward, contacting the inner ring, The conductive material is a circular conductive felt. The annular felt has an extension portion extending radially outward from radially outer ends of the first metal plate and the second metal plate, The outer circumferential surface of the annular felt contacts the outer ring. Bearing seal.

3. A rubber piece extending in a radial direction is attached to the extending portion of the annular felt, The rubber pieces are arranged at substantially equal intervals in the circumferential direction. A bearing seal according to claim 1 or 2.

4. A rubber film is attached to the extended portion of the annular felt so as to cover substantially the entire surface of the exposed portion. A bearing seal according to claim 1 or 2.

5. a seal lip is provided on the inner side of the extension portion of the annular felt in the width direction of the rolling bearing, the seal lip extending away from the exposed portion and contacting the inner ring or the outer ring; A bearing seal according to claim 1 or 2.

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