Bearing seal

Abstract

To facilitate manufacturing of a bearing seal which prevents electric corrosion of a roller bearing.SOLUTION: A bearing seal 1 is used for a roller bearing and includes an annular seal ring 2. The seal ring 2 has: a core grid 3 having a portion 3B which contacts with an outer ring 11; and an elastic body 4 joined to a surface at the outer side BO in a width direction of the core grid 3. The elastic body 4 has an inner diameter lip part 7 which extends to an outer peripheral surface 12A of an inner ring 12 and inclines to the outer side BO in the width direction in a direction toward the outer peripheral surface 12A. The bearing seal 1 includes a conductive member 5 which is sandwiched to be held by an inner diameter part D extending in a substantially radial direction R between the core grid 3 and the elastic body 4. The conductive member 5 has a portion which contacts with the inner ring 12, and its form in a state before the bearing seal 1 is attached to the roller bearing is an annular shape located on the substantially same plane. In the state that the bearing seal 1 is attached to the roller bearing, the conductive member 5 which is pressed by restoring force of the elastically deformed inner diameter lip part 7 is in contact with the inner ring 12.SELECTED DRAWING: Figure 3

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, as well as 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 outer and inner rings, causing damage to the rolling surfaces of the rolling elements due to arcing.

[0003] As a bearing seal for preventing electrolytic corrosion of such rolling bearings, there is one provided with a conductive material for electrically conducting the outer ring and the inner ring (see, for example, Patent Documents 1 and 2).

[0004] The bearing seal (sealing material A) in Patent Document 1 has a structure in which it has an elastic body B and a reinforcing material 2, and electrically conductive material 3, which is a conductive material, is embedded (Fig. 1) or attached (Fig. 2) to elastic body B, and electrically conductive material 3 is connected to fitting portion A1 which fits into outer ring 1b and sliding portion A2 which makes sliding contact with inner ring 1a. Electrically conductive material 3 is a wire, plate, foil, or the like.

[0005] The bearing seal (seal assembly 04) in Patent Document 2 has a structure in which it has a seal 05 consisting of an elastomer body 08 and a reinforcing material 09, and a circular conductive element 14, which is a conductive material, is affixed to the seal 05, with the outer diameter side of the conductive element 14 contacting the outer ring 02 and the inner diameter side of the conductive element 14 slidingly contacting the inner ring 03 (FIG. 1). The conductive element 14 is a conductive fiber fabric made of carbon fiber, carbon fiber derivatives, metal fiber, or filled polymer fiber embedded in an elastomer matrix, i.e., a conductive elastomer.

[0006] In the seal assembly 04, the conductive element 14 is located on the opposite side (outer in the width direction) of the space to be sealed within the rolling bearing, and the radial outer and inner peripheral portions of the conductive element 14 are inclined outward in the width direction of the rolling bearing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 62-106125 [Patent Document 2] U.S. Pat. No. 11,493,133 Summary of the Invention [Problem to be solved by the invention]

[0008] In the case of the bearing seal (Figure 1) in Patent Document 1, which has a structure in which an electrically conductive material such as a wire, plate or foil is embedded in an elastic body, it is difficult to manufacture the electrically conductive material so that it penetrates the elastic body in the radial direction and protrudes from a predetermined position on the elastic body to ensure sliding contact with the inner ring.

[0009] In the case of the bearing seal ( FIG. 2 ) in Patent Document 1, which has a structure in which an electrically conductive material such as a wire, plate or foil is attached to an elastic body, the electrically conductive material needs to be attached to conform to the shape of the bearing seal, which has a relatively complex shape, and the electrically conductive material needs to be connected so as to come into contact with the outer ring and the inner ring, making it difficult to manufacture.

[0010] Even in the case of a bearing seal in which the outer and inner diameter sides of a conductive elastomer come into contact with the outer and inner rings as in Patent Document 2, the conductive elastomer must be attached to conform to the shape of the bearing seal, which has a relatively complex shape, and the conductive elastomer must be connected so as to come into contact with the outer and inner rings, making manufacturing difficult.

[0011] In the case of a bearing seal in which a conductive elastomer slides against the inner ring, as in Patent Document 2, the carbon fibers etc. embedded in the elastomer are affected by the state of dispersion within the elastomer, resulting in high conductive resistance, and in the presence of a lubricant (grease, oil, etc.), an oil film forms on the sliding surface between the conductive elastomer and the inner ring, making contact between the conductive elastomer and the inner ring unstable for passing electricity.

[0012] In the bearing seal of Patent Document 2, the conductive material is located on the opposite side (outer in the width direction) to the space to be sealed inside the rolling bearing, and the outer and inner radial parts of the conductive material are inclined outward in the width direction. Therefore, the conductive material may protrude outward in the width direction beyond the end faces in the width direction of the rolling bearing, and the rolling bearings in which the bearing seal can be used are limited.

[0013] An object of the present invention is to facilitate the manufacture of a bearing seal that prevents electrolytic corrosion in a rolling bearing, and to reduce electrical resistance and improve electrical stability in the bearing seal. [Means for solving the problem]

[0014] A bearing seal according to a first aspect of the present invention is a bearing seal including an annular seal ring used in a rolling bearing including an outer ring, an inner ring, and rolling elements. The seal ring includes a core metal having a portion that contacts the outer ring, and an elastic body joined to the outer surface of the core metal in the width direction. The elastic body has an inner diameter lip portion that extends toward the outer peripheral surface of the inner ring and inclines outward in the width direction as it approaches the outer peripheral surface. The seal ring includes a conductive material sandwiched and held in an inner diameter portion extending in a substantially radial direction between the core metal and the elastic body. The conductive material has a portion that contacts the inner ring, and its shape before being mounted on the rolling bearing is annular and located in substantially the same plane. When mounted on the rolling bearing, the conductive material is pressed by the restoring force of the elastically deformed inner diameter lip portion and contacts the inner ring.

[0015] A bearing seal according to a second aspect of the present invention is a bearing seal including an annular seal ring used in a rolling bearing including an outer ring, an inner ring, and rolling elements. The seal ring includes a core metal having a portion that contacts the outer ring, and an elastic body joined to the outer surface of the core metal in the width direction. The elastic body has an inner diameter lip portion that extends toward the outer peripheral surface of the inner ring and inclines outward in the width direction as it approaches the outer peripheral surface. The inner diameter lip portion is a contact type or non-contact type seal. The seal includes a conductive material sandwiched and held by an inner diameter portion extending in a substantially radial direction between the core metal and the elastic body. The conductive material has a portion that contacts the inner ring, and its shape before being attached to the rolling bearing is annular and located in substantially the same plane. The elastic body has an attachment portion joined to the outer surface of the conductive material in the width direction. When attached to the rolling bearing, the conductive material is pressed by the restoring force of the elastically deformed attachment portion and contacts the inner ring.

[0016] According to the configuration of the bearing seal according to the first or second aspect, the core metal contacts the outer ring of the rolling bearing, and the conductive material held between the core metal and the elastic body contacts the inner ring of the rolling bearing, so that the outer ring and the inner ring are electrically connected. Before the bearing seal is mounted on the rolling bearing, the conductive material has a circular shape located in approximately the same plane. Therefore, it is not necessary to connect the conductive material along the seal ring having a relatively complex shape. Furthermore, since the conductive material has the circular shape before the bearing seal is mounted on the rolling bearing and has a short radial length, the conductive material can be easily manufactured. Furthermore, the conductive material is held in a state where it is sandwiched between the core metal and the elastic body and in the inner diameter portion extending approximately in the radial direction. From the above, the bearing seal made of the core metal, the elastic body, and the conductive material can be easily manufactured.

[0017] A bearing seal according to a third aspect of the present invention is the bearing seal according to the first or second aspect, wherein the conductive material is a circular ring of cloth-like or non-woven conductive fibers, a circular metal foil, or a circular conductive felt formed by entangling the conductive fibers themselves.

[0018] In the configuration of the bearing seal pertaining to the third aspect, the conductive material is the conductive fibers molded into an annular shape, a circular metal foil, or annular conductive felt molded by entangling the conductive fibers themselves, and is not a conductive elastomer. Therefore, electrical resistance between the conductive material and the inner ring is low, and no oil film is formed, as is the case with the sliding surfaces between a conductive elastomer and the inner ring in the presence of a lubricant, so contact for electrical conduction is stable. Effect of the Invention

[0019] As described above, the bearing seal according to the first or second aspect of the present invention facilitates the manufacture of a bearing seal that prevents electrolytic corrosion of a rolling bearing. Also, the configuration of the bearing seal according to the third aspect of the present invention reduces electrical resistance between the conductive material and the inner ring and stabilizes contact for electrical conduction. [Brief description of the drawings]

[0020] [Figure 1] 1 is an enlarged longitudinal sectional view of a main portion of a rolling bearing provided with a bearing seal according to an embodiment of the present invention; [Diagram 2] 2 is an enlarged longitudinal sectional view of a main portion showing one of the bearing seals in the rolling bearing of FIG. 1 and its surroundings. [Diagram 3] FIG. 2 is a cut-away end view showing the shape of the bearing seal before the bearing seal is incorporated into a rolling bearing. [Figure 4] FIG. 2 is an enlarged longitudinal sectional view of a main portion of a rolling bearing provided with a bearing seal of a first modified example. [Diagram 5] FIG. 11 is an enlarged longitudinal sectional view of a main portion of a rolling bearing provided with a bearing seal of a second modified example. [Figure 6] FIG. 11 is a sectional end view showing the shape of the bearing seal of the second modified example before the bearing seal of the second modified example is incorporated into a rolling bearing. [Figure 7] FIG. 11 is an enlarged longitudinal sectional view of a main portion of a rolling bearing provided with a bearing seal according to a third modified example. [Figure 8] FIG. 11 is a sectional end view showing the shape of the bearing seal of the third modified example before the bearing seal of the third modified example is incorporated into a rolling bearing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] In this specification, the direction parallel to the direction of the central axis of rotation of the rolling bearing is referred to as the "width direction" (see, for example, arrow B in Figure 1), and the direction perpendicular to the direction of the central axis of rotation is referred to as the "radial direction" (see, for example, arrow R in Figure 1).

[0023] In this specification, the width direction approaching the widthwise center of the rolling bearing (symbol C in Figure 1) is referred to as the "widthwise inward" (see, for example, arrow BI in Figure 1), the width direction moving away from the widthwise center is referred to as the "widthwise outward" (see, for example, arrow BO in Figure 1), the radial direction approaching the central axis of rotation is referred to as the "radial inward" (see, for example, arrow RI in Figure 1), 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 1).

[0024] [Rolling bearings] 1 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 surfaces of the outer ring 11 and the inner ring 12. The cage 14 guides the rolling elements 13 at a predetermined interval and holds them rotatably.

[0025] [Bearing seal] The bearing seal 1 shown in the cross-sectional views of Figures 1 and 2 comprises an annular seal ring 2 and an electrically conductive material 5. The seal ring 2 has an annular core metal 3 made of, for example, steel, and an annular elastic body 4 made of a rubber material. The elastic body 4 is joined to the outer surface BO of the core metal 3 in the width direction. The electrically conductive material 5 is electrically conductive with the core metal 3 and the inner ring 12.

[0026] (Core wire) The core metal 3 is a plate material and is composed of an inner diameter portion 3A, an outer diameter portion 3B, and an annular portion 9A, an inner connecting portion 9B, and an outer connecting portion 9C located between the inner diameter portion 3A and the outer diameter portion 3B. The inner diameter portion 3A and the outer diameter portion 3B are annular extending in the approximately radial direction R. The inner connecting portion 9B has a truncated cone side surface shape connecting the inner diameter portion 3A and the annular portion 9A, and the outer connecting portion 9C has a truncated cone side surface shape connecting the outer diameter portion 3B and the annular portion 9A. The surface of the inner diameter portion 3A on the outer side in the width direction BO faces the conductive material 5.

[0027] (Elastic body) The elastic body 4 is composed of an attachment portion 6, an inner diameter lip portion 7, an inner diameter portion 8A, an outer diameter engagement portion 8B, and an annular portion 10A, an inner connecting portion 10B, and an outer connecting portion 10C located between the inner diameter portion 8A and the outer diameter engagement portion 8B. The inner diameter portion 8A and the outer diameter engagement portion 8B are annular in shape extending approximately in the radial direction R. The inner connecting portion 10B has a truncated cone side surface shape connecting the inner diameter portion 8A and the annular portion 10A, and the outer connecting portion 10C has a truncated cone side surface shape connecting the outer diameter engagement portion 8B and the annular portion 10A.

[0028] The attachment portion 6 is thin and joined to the conductive material 5. The widthwise inward surface BI of the inner diameter portion 8A faces the conductive material 5. The inner diameter lip portion 7 protrudes from the end portion on the radially inward RI side of the inner diameter portion 8A. The inner diameter lip portion 7 inclines widthwise outward BO as it approaches the outer peripheral surface 12A of the inner ring 12 (as it moves radially inward RI). The outer diameter engagement portion 8B engages with the engagement groove 11A of the outer ring 11. With the outer diameter engagement portion 8B of the elastic body 4 engaged with the engagement groove 11A of the outer ring 11, the outer diameter portion 3B of the core bar 3 comes into contact with the outer ring 11.

[0029] (Conductive material) The conductive material 5 is sandwiched and held between the inner diameter portion 3A of the core 3 and the inner diameter portion 8A of the elastic body 4, i.e., in the inner diameter portion D extending approximately in the radial direction R between the core 3 and the elastic body 4, and has an inner diameter side end portion 5A which is a portion which contacts the inner ring 12. An outer diameter side end 5B which is an end portion on the radially outer RO side of the conductive material 5 is located at an end portion on the radially outer RO side of the inner diameter portion 3A of the core 3 and an end portion on the radially inner RI side of the inner coupling portion 9B of the core 3. Therefore, the conductive material 5 can be easily positioned with respect to the core 3.

[0030] The conductive material 5 is a circular ring of conductive cloth or nonwoven conductive fibers, a circular metal foil, or a circular felt made by entangling conductive fibers. The conductive fibers are made of carbon fibers or chemical fibers coated with a metal. The metals used to coat the chemical fibers are copper, silver, and / or nickel. The carbon fibers can be reinforced by mixing them with polyester resin, polyvinyl chloride resin, or the like.

[0031] The conductive material 5 of the bearing seal 1 is a circular ring of cloth-like or nonwoven conductive fibers, a circular metal foil, or a circular felt having conductivity formed by entangling the conductive fibers themselves, and is not a conductive elastomer. Therefore, the electrical resistance between the conductive material 5 and the inner ring 12 is small, and an oil film is not formed, as is the case with the sliding surface between a conductive elastomer and the inner ring in the presence of a lubricant, so contact for electrical conduction is stable.

[0032] [Shape of conductive material before mounting bearing seal to rolling bearing] Before the bearing seal 1 shown in the cross-sectional end view of FIG. 3 is assembled into the rolling bearing A, the conductive material 5 has an annular shape located in approximately the same plane including the radial direction R. Therefore, it is not necessary to connect the conductive material 5 along the seal ring 2 having a relatively complicated shape. Furthermore, since the conductive material 5 has the annular shape before the bearing seal 1 is mounted into the rolling bearing A and has a short length in the radial direction R, the conductive material 5 can be easily manufactured. Furthermore, the conductive material 5 is held in a state sandwiched between the core metal 3 and the elastic body 4 and in the inner diameter portion D extending approximately in the radial direction R. From the above, the bearing seal 1 consisting of the core metal 3, the elastic body 4, and the conductive material 5 can be easily manufactured.

[0033] [Installation of bearing seals on rolling bearings] When the bearing seal 1 is mounted on the rolling bearing A (FIG. 1) from the state shown in FIG. 3 as shown in FIG. 2, the conductive material 5 in contact with the widthwise end face 12B of the inner ring 12 is deformed so as to bend. As a result, as shown in FIG. 2, the radially inward RI portion of the conductive material 5 is inclined toward the widthwise outward RO as it moves toward the radially inward RI, and the inner diameter side end portion 5A of the conductive material 5 comes into contact with the outer circumferential surface 12A of the inner ring 12. The attachment portion 6 and the inner diameter lip portion 7 of the elastic body 4 press the conductive material 5 in an elastically deformed state, so that the contact of the conductive material 5 with the inner ring 12 is stable.

[0034] With the bearing seal 1 mounted on the rolling bearing A in this manner, the outer diameter engagement portion 8B of the elastic body 4 is engaged with the engagement groove 11A of the outer ring 11, and the outer diameter portion 3B of the core metal 3 is in contact with the outer ring 11. Therefore, the core metal 3 of the bearing seal 1 contacts the outer ring 11, and the conductive material 5 held between the core metal 3 and the elastic body 4 contacts the inner ring 12, so that the outer ring 11 and the inner ring 12 are electrically connected.

[0035] [Variations] (First Modification) The portion of the core bar 3 that comes into contact with the outer ring 11 may be an engagement portion 3C as shown in the cross-sectional view of Fig. 4. That is, in the example of Fig. 4, an engagement portion 3C provided at the end of the core bar 3 on the radially outward RO side engages with an engagement groove 11A of the outer ring 11, so that the core bar 3 comes into contact with the outer ring 11. The elastic body 4 in the bearing seal 1 of Fig. 4 does not have the outer diameter engagement portion 8B shown in Fig. 2, nor does it have an annular portion 10A. Note that in the example of Fig. 4, an annular portion 10A may be provided.

[0036] (Second Modification) The bearing seal 1 shown in the cross-sectional view of Figure 5 and the cut-away end view of Figure 6 shows an example in which the attachment portion 6 of the elastic body 4 is eliminated from the example shown in the cross-sectional view of Figure 2 and the cut-away end view of Figure 3.

[0037] When the bearing seal 1 is mounted on the rolling bearing A (FIG. 1) from the state shown in FIG. 6 as shown in FIG. 5, the conductive material 5 in contact with the widthwise end face 12B of the inner ring 12 is deformed so as to bend. As a result, as shown in FIG. 5, the radially inward RI portion of the conductive material 5 is inclined toward the widthwise outward RO as it moves toward the radially inward RI, and the inner diameter side end 5A of the conductive material 5 comes into contact with the outer circumferential surface 12A of the inner ring 12. The inner diameter lip portion 7 of the elastic body 4 is attached to the widthwise outward BO surface of the conductive material 5, and the inner diameter lip portion 7 presses the conductive material 5 in an elastically deformed state, so that the contact of the conductive material 5 with the inner ring 12 is stable.

[0038] (Third Modification) The bearing seal 1 shown in the cross-sectional view of Figure 7 and the cut-away end view of Figure 8 illustrates an example in which, in the example shown in the cross-sectional view of Figure 2, the inner diameter lip portion 7 of the elastic body 4 and the conductive material 5 are spaced apart so that the conductive material 5 is not pressed by the inner diameter lip portion 7.

[0039] When the bearing seal 1 is mounted on the rolling bearing A (FIG. 1) from the state shown in FIG. 8 as shown in FIG. 7, the conductive material 5 in contact with the widthwise end face 12B of the inner ring 12 is deformed so as to bend. As a result, as shown in FIG. 7, the radially inward RI portion of the conductive material 5 is inclined toward the widthwise outward RO as it moves toward the radially inward RI, and the inner diameter side end 5A of the conductive material 5 comes into contact with the outer peripheral surface 12A of the inner ring 12. The attachment portion 6 of the elastic body 4 is joined to the surface of the conductive material 5 toward the widthwise outward BO, and the attachment portion 6 presses the conductive material 5 with mainly the root portion 6A of the attachment portion 6 elastically deformed, so that the contact of the conductive material 5 with the inner ring 12 is stable.

[0040] In the example of the bearing seal 1 shown in Figure 7, the inner lip portion 7 forms a contact-type seal, but it may also be a non-contact type seal in which the tip 7A of the inner lip portion 7 is separated from the outer peripheral surface 12A of the inner ring 12.

[0041] 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]

[0042] 1 Bearing seal 2 Seal ring 3 Core wire 3A Inner diameter part 3B Outer diameter part (part that contacts the outer ring) 3C Engagement part (part that contacts the outer ring) 4 Elastic Body 5 Conductive materials 5A Inner diameter end (part that contacts the inner ring) 5B Outer diameter end 6 Attachment 6A Base 7 Inner lip 7A tip 8A Inner diameter 8B Outer diameter engagement part 9A Circular Ring 9B Inner connection part 9C Outer connection part 10A Circular Ring 10B Inner connection part 10C Outer connection part 11 Outer ring 11A Engagement groove 12 Inner Circle 12A Outer surface 12B Width end face 13 Rolling elements 14 Cage A Rolling bearing B Width direction BI Width direction inside BO Width direction outward C Width center D: The inner diameter portion extending approximately in the radial direction between the core metal and the elastic body R Radial direction RI radially inward RO radially outward

Claims

1. A bearing seal including an annular seal ring for use in a rolling bearing including an outer ring, an inner ring, and a rolling element, the seal ring includes a core having a portion that contacts the outer ring, and an elastic body joined to an outer surface of the core in a width direction, the elastic body has an inner diameter lip portion that extends toward an outer circumferential surface of the inner ring and inclines outward in a width direction as it approaches the outer circumferential surface, a conductive material sandwiched and held in an inner diameter portion extending in a substantially radial direction between the core metal and the elastic body, the conductive material has a portion that contacts the inner ring, and has a shape that is annular and located in substantially the same plane before being mounted on the rolling bearing, When the conductive material is mounted on the rolling bearing, the conductive material is pressed by a restoring force of the elastically deformed inner diameter lip portion and comes into contact with the inner ring. Bearing seal.

2. A bearing seal including an annular seal ring for use in a rolling bearing including an outer ring, an inner ring, and a rolling element, the seal ring includes a core having a portion that contacts the outer ring, and an elastic body joined to an outer surface of the core in a width direction, the elastic body has an inner diameter lip portion that extends toward an outer circumferential surface of the inner ring and inclines outward in a width direction as it approaches the outer circumferential surface, The inner diameter lip portion is a contact or non-contact type seal, a conductive material sandwiched and held in an inner diameter portion extending in a substantially radial direction between the core metal and the elastic body, the conductive material has a portion that contacts the inner ring, and has a shape that is annular and located in substantially the same plane before being mounted on the rolling bearing, the elastic body has an attachment portion joined to an outer surface of the conductive material in a width direction, When the conductive material is attached to the rolling bearing, the conductive material is pressed by a restoring force of the elastically deformed attachment portion and comes into contact with the inner ring. Bearing seal.

3. The conductive material is a circular ring of conductive cloth or nonwoven conductive fibers, a circular metal foil, or a circular felt having conductivity and formed by entangling conductive fibers. A bearing seal according to claim 1 or 2.

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