Sliding members and rolling bearings
A conductive sliding member with a non-woven or woven fabric and metal ring configuration enhances conductivity, addressing the need for improved anti-electric corrosion in rolling bearings by reducing potential differences and preventing electrolytic corrosion.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JTEKT SEALING TECHNO CORP
- Filing Date
- 2023-11-15
- Publication Date
- 2026-07-08
AI Technical Summary
Existing rolling bearings with anti-electric corrosion features require further enhancement in conductivity to effectively suppress electrical corrosion of raceways and rolling elements.
A sliding member composed of a non-woven or woven fabric of conductive fibers, integrated with a metal ring and rubber, is positioned between the inner and outer rings of the bearing, allowing for electrical connection and dissipation of current to prevent electrolytic corrosion.
The conductive sliding member effectively reduces potential differences between the inner and outer rings, thereby suppressing electrolytic corrosion of raceways and rolling elements.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a sliding member and a rolling bearing.
Background Art
[0002] A rolling bearing having an anti-electric corrosion function is disclosed in Patent Document 1. The rolling bearing described in Patent Document 1 is a bearing that supports the rotating shaft of an electric motor mounted on an electric vehicle or the like. This rolling bearing includes an outer ring, an inner ring, a plurality of balls disposed between the outer ring and the inner ring, and an annular seal (sliding member) that closes the end opening of the bearing internal space between the outer ring and the inner ring. The seal includes an elastic material such as rubber having conductivity. The inner peripheral edge and the outer peripheral edge of this elastic material are in contact with the inner ring and the outer ring, respectively. By the elastic material contacting the inner ring and the outer ring, the inner ring is electrically connected to the outer ring through the elastic material, and the flow of current between the inner ring and the balls and between the outer ring and the balls is suppressed, and the electrical corrosion of the raceway of the inner ring, the raceway of the outer ring, and the balls is suppressed.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The elastic material of the seal (sliding member) in Patent Document 1 has a certain degree of conductivity by kneading carbon fiber into rubber. On the other hand, in order to further suppress the electrical corrosion of the raceway, it is required to further increase the conductivity of the seal. Therefore, the present disclosure aims to increase the conductivity of the sliding member.
Means for Solving the Problems
[0005] (1) The sliding member of the present disclosure is a sheet that is a non-woven fabric or a woven fabric formed of conductive fibers, A metal ring, Equipped with rubber, The aforementioned sheet is A fixing portion is fixed to the first member made of steel on the first radial side of the metal ring, A sliding portion that slidably contacts a second member made of steel on the second radial side, It integrally includes an intermediate portion located between the fixed portion and the sliding portion, The metal ring is positioned at a distance from the sheet on the first axial side, The rubber has first portions arranged at the aforementioned intervals.
[0006] (2) The rolling bearing of the present disclosure comprises an inner ring having an inner ring raceway, An outer ring having an outer ring raceway arranged radially outside the inner ring raceway, A plurality of rolling elements are arranged to be rotatable between the inner ring raceway and the outer ring raceway, The sliding member described in (1) above is disposed radially between the axial end of the inner ring and the axial end of the outer ring, One of the inner ring and the outer ring is the first member, The other of the inner ring and the outer ring is the second member. [Effects of the Invention]
[0007] The sliding member of this disclosure comprises a sheet which is a nonwoven or woven fabric formed of conductive fibers, and this sheet can have lower electrical resistance and higher conductivity than an elastic material which is rubber mixed with carbon fibers. Therefore, the sliding member electrically connects a first member and a second member by the sheet, and current can be passed from one of the first member and the second member to the other through this sheet. [Brief explanation of the drawing]
[0008] [Figure 1] Figure 1 is a cross-sectional view showing an example of a rolling bearing according to this disclosure. [Figure 2] Figure 2 is an enlarged cross-sectional view of the sliding member. [Figure 3] Figure 3 is an enlarged cross-sectional view of the radially outer portion of the sliding member shown in Figure 2. [Figure 4] Figure 4 is an enlarged cross-sectional view of the radially inner portion of the sliding member shown in Figure 2. [Figure 5] Figure 5 is a cross-sectional view showing a part of the molding die for the sliding member. [Modes for carrying out the invention]
[0009] <Summary of Embodiments of the Invention Disclosed> The embodiments of the invention disclosed herein are outlined below.
[0010] (1) The sliding member of the present disclosure is a sheet which is a nonwoven or woven fabric formed of conductive fibers, A metal ring, Equipped with rubber, The aforementioned sheet is A fixing portion is fixed to the first member made of steel on the first radial side of the metal ring, A sliding portion that slidably contacts a second member made of steel on the second radial side, It integrally includes an intermediate portion located between the fixed portion and the sliding portion, The metal ring is positioned at a distance from the sheet on the first axial side, The rubber has first portions arranged at the aforementioned intervals.
[0011] In this configuration, the sliding member comprises a sheet which is a nonwoven or woven fabric made of conductive fibers. The sheet has lower electrical resistance and higher conductivity than an elastic material made by kneading carbon fibers into rubber. Therefore, the sliding member electrically connects the first member and the second member by the sheet, and current can be passed from one of the first member and the second member to the other through this sheet.
[0012] (2) Preferably, the sliding member in (1) above further includes a second portion where the rubber is disposed on the first side in the radial direction with respect to the first portion, and a third portion where the rubber is disposed on the second side in the radial direction with respect to the first portion. The first portion, the second portion, and the third portion are adhered to the entire first side in the axial direction of the seat.
[0013] With such a configuration, the shape of the entire seat can be held by the rubber.
[0014] (3) Preferably, the sliding member in (1) or (2) above has a fourth portion where the rubber is disposed on the first side in the axial direction with respect to the metal ring beyond the radial end of the metal ring.
[0015] With such a configuration, the connection between the rubber and the metal ring can be strengthened. Also, since the fourth portion is disposed on the side opposite to the seat in the axial direction, the fourth portion will not damage the seat.
[0016] (4) The rolling bearing of the present disclosure has an inner ring having an inner ring raceway, an outer ring having an outer ring raceway disposed on the outer side in the radial direction of the inner ring raceway, a plurality of rolling elements disposed rotatably between the inner ring raceway and the outer ring raceway, and the sliding member according to any one of (1) to (3) above disposed between the radial directions of the axial end of the inner ring and the axial end of the outer ring, and includes one of the inner ring and the outer ring is the first member, and the other of the inner ring and the outer ring is the second member.
[0017] According to this configuration, the outer ring and the inner ring of the rolling bearing can be electrically connected by the seat of the sliding member, and a current can flow from one of the outer ring and the inner ring to the other through this seat, suppressing the electrical erosion of the outer ring raceway, the inner ring raceway, and the balls.
[0018] (5) Preferably, the rolling bearing of (4) above is In the axial direction, the sheet of the sliding member is positioned closer to the rolling element than the metal ring and the rubber.
[0019] This configuration makes it easier to bring the sliding portion of the sliding member into contact with the inner or outer ring.
[0020] <Details of Embodiments of the Invention in This Disclosure> Embodiments of the invention described herein will be explained below. Figure 1 is a cross-sectional view showing an example of a rolling bearing according to this disclosure. The rolling bearing 10 shown in Figure 1 supports the rotating shaft S of a motor mounted in, for example, an electric vehicle or a hybrid vehicle. In Figure 1, the rotating shaft S is indicated by a dashed line (two-dot dashed line).
[0021] The rolling bearing 10 comprises an outer ring 11, an inner ring 12, a plurality of rolling elements 13, a cage 14, and a sliding member 15. In this embodiment, the rolling elements 13 are balls. The rolling bearing 10 is a deep groove ball bearing. The outer ring 11 is mounted on the housing H of the motor. The inner ring 12 is fitted and fixed to the outer circumferential surface of the rotating shaft S. In Figure 1, the housing H is shown by a dashed line (two-dot dashed line). In this embodiment, the outer ring 11 is a stationary ring, and the inner ring 12 is a rotating ring. The outer ring 11 and the inner ring 12 are formed from a steel material such as bearing steel. High-carbon chromium bearing steel (for example, SUJ2 or SUJ3 as defined in JIS standards) can be used as the bearing steel. However, the outer ring 11 and the inner ring 12 may be made of other steel materials such as carburized bearing steel, carbon steel, chromium steel, or stainless steel.
[0022] The outer ring 11 and the inner ring 12 are arranged concentrically. In this embodiment, the central axes of the outer ring 11 and the inner ring 12 coincide with the central axis C of the rolling bearing 10. Furthermore, in this embodiment, the direction along the central axis C and the direction parallel to the central axis C are defined as the "axial direction". Similarly, the direction perpendicular to the central axis C is defined as the "radial direction". Similarly, the direction along the circle centered on the central axis C is defined as the "circumferential direction". Also, in this embodiment, the left side of Figure 1 is the first axial side, the right side of Figure 1 is the second axial side, the upper side of Figure 1 is the first radial side, and the lower side of Figure 1 is the second radial side. Also, in this embodiment, the first radial side is the radially outer side, and the second radial side is the radially inner side. Therefore, in the following description, the first radial side may be referred to as the radially inner side, and the second radial side may be referred to as the radially outer side.
[0023] The outer ring 11 comprises an outer ring raceway 21, two shoulders 22, and two annular grooves 23. The outer ring raceway 21 is provided on the inner circumferential surface of the outer ring 11. The ball 13 rolls along this outer ring raceway 21. The two shoulders 22 are provided on both axial sides of the outer ring raceway 21. The two annular grooves 23 are provided between the shoulders 22 and the axial sides of the outer ring 11. The annular grooves 23 have an annular groove shape that is continuous in the circumferential direction. The sliding member 15 is attached to the annular grooves 23 located on both axial sides of the outer ring 11. However, the sliding member 15 may be attached only to the annular grooves 23 located on either the first or second axial side of the outer ring 11. In this case, the annular grooves 23 to which the sliding member 15 is not attached may be omitted.
[0024] The inner ring 12 comprises an inner ring raceway 31, two shoulders 32, and two sliding member contact surfaces 33. The inner ring raceway 31 is provided on the outer circumferential surface of the inner ring 12. The ball 13 rolls along this inner ring raceway 31. The two shoulders 32 are provided on both axial sides of the inner ring raceway 31. The two sliding member contact surfaces 33 are provided between the shoulders 32 and the sides of the inner ring 12. The sliding member contact surfaces 33 are provided in an annular shape around the entire circumference of the inner ring 12. The sliding member contact surfaces 33 have a groove shape in a cross-section including the central axis C of the inner ring 12. The radial inner end of the sliding member 15 is in contact with the sliding member contact surface 33.
[0025] The ball 13 is positioned between the outer ring 11 and the inner ring 12. The ball 13 rolls and makes contact with the outer ring raceway 21 and the inner ring raceway 31. Multiple balls 13 are held circumferentially at intervals by an annular retainer 14.
[0026] The retainer 14 has an annular body 16 and a plurality of horns (columns) 17. The annular body 16 is located on the second axial side of the ball 13. The plurality of horns (columns) 17 extend from the annular body 16 on the first axial side. The pocket 18 is the space between two circumferentially adjacent horns 17 on the first axial side of the annular body 16. The pocket 18 accommodates the ball 13. The pocket 18 is open on the first axial side.
[0027] The sliding member 15 is formed in an annular shape. The sliding member 15 is fixed to the outer ring (first member) 11 and slides against the inner ring (second member) 12. Specifically, the sliding member 15 is fixed to the outer ring 11 by fitting its radially outer end (the end on the first radial side) into the annular groove 23 of the outer ring 11. The radially inner end (the end on the second radial side) of the sliding member 15 is in contact with the sliding member contact surface 33 of the inner ring 12. The sliding member 15 is provided on both axial sides of the rolling bearing 10. Therefore, the annular space between the outer ring 11 and the inner ring 12, the bearing internal space K1 in which the ball 13 exists, is closed off by the sliding member 15 on both axial sides. The sliding member 15 separates the bearing internal space K1 in which the ball 13 exists from the bearing external space K2, which is the space on the first and second axial sides of the rolling bearing 10.
[0028] The sliding member 15 includes a conductive sheet 43 positioned between its radially outer end and radially inner end. At the radially outer end of the sliding member 15, the sheet 43 is exposed on the surface and in contact with the annular groove 23 of the outer ring 11. At the radially inner end of the sliding member 15, the sheet 43 is exposed on the surface and in contact with the sliding member contact surface 33 of the inner ring 12. Therefore, the sliding member 15 constitutes an energizing path to suppress the flow of current generated by a motor or the like between the outer ring 11 and the inner ring 12 via the rolling elements 13. An oil film of lubricating oil or grease is formed between the ball 13 and the inner ring raceway 31, and between the ball 13 and the outer ring raceway 21. The oil film has insulating properties. Due to the insulating properties of the oil film, the ball 13 is insulated from the inner ring raceway 31 and the outer ring raceway 21. When an oil film is formed between the ball 13 and the inner ring raceway 31, and a potential difference of less than a predetermined value occurs between the ball 13 and the inner ring raceway 31, no current flows between the inner ring raceway 31 and the ball 13. When an oil film is formed between the ball 13 and the outer ring raceway 21, and a potential difference of less than a predetermined value occurs between the ball 13 and the outer ring raceway 21, no current flows between the ball 13 and the outer ring raceway 21. However, when the oil film between the ball 13 and the inner ring raceway 31 is partially destroyed, or when a potential difference exceeding a predetermined value occurs between the ball 13 and the inner ring raceway 31, current flows between the ball 13 and the inner ring raceway 31, and this current may cause electrolytic corrosion on the ball 13 and / or the inner ring raceway 31. When the oil film between the ball 13 and the outer ring raceway 21 is partially destroyed, or when a potential difference exceeding a predetermined value occurs between the ball 13 and the outer ring raceway 21, current flows between the ball 13 and the outer ring raceway 21, and this current can cause electrolytic corrosion on the ball 13 and / or the outer ring raceway 21. In this embodiment, the rolling bearing 10 is provided with a sliding member 15 that forms an energizing path, so that the potential difference between the outer ring 11 and the inner ring 12 is reduced by allowing current to flow between the outer ring 11 and the inner ring 12 via the sliding member 15 before the potential difference between the ball 13 and the inner ring raceway 31 or the potential difference between the ball 13 and the outer ring raceway 21 becomes large. By reducing the potential difference between the outer ring 11 and the inner ring 12, the occurrence of electrolytic corrosion on the ball 13, the inner ring raceway 31 and the outer ring raceway 21 is suppressed.
[0029] [Specific structure of the sliding member 15] Figure 2 is an enlarged cross-sectional view of the sliding member. Figure 3 is an enlarged cross-sectional view of the radially outer portion of the sliding member in Figure 2. Figure 4 is an enlarged cross-sectional view of the radially inner portion of the sliding member in Figure 2. In the following description, the specific structure of the sliding member 15 located on the first axial side (left side in Figure 1) of the rolling bearing 10 will be explained. Therefore, in this description of the sliding member 15, the first axial side can be rephrased as the bearing external space K2 side, and the second axial side can be rephrased as the bearing internal space K1 side. The sliding member 15 located on the second axial side (right side in Figure 1) of the rolling bearing 10 is the same part as the sliding member 15 located on the first side, but it is located inverted in the axial direction.
[0030] As shown in Figures 2 to 4, the sliding member 15 has a metal ring 41, a rubber 42, and a sheet 43. The metal ring 41, the rubber 42, and the sheet 43 are all annular. The metal ring 41 and the rubber 42, and the rubber 42 and the sheet 43 are bonded to each other, and they form a single integrated unit.
[0031] The metal ring 41 is formed from a metal such as galvanized steel sheet or stainless steel. The metal ring 41 is formed by processing a sheet material. The metal ring 41 includes an annular portion 41a and a cylindrical portion 41b. The annular portion 41a is positioned perpendicular to the axial direction. The cylindrical portion 41b is positioned parallel to the axial direction. The cylindrical portion 41b is positioned at the radially outer end of the annular portion 41a. The cylindrical portion 41b extends from the radially outer end of the annular portion 41a to the second axial side (bearing internal space K1 side). The annular portion 41a and the cylindrical portion 41b of the metal ring 41 are formed by plastically deforming a sheet material into a substantially L-shaped cross-section.
[0032] The rubber 42 is electrically conductive. Specifically, the rubber 42 is manufactured, for example, by compounding a conductive material with synthetic rubber. The conductive material may be carbon black, metal powder, etc. The specific structure of this rubber 42 will be described later, along with the structure of the sheet 43.
[0033] The sheet 43 is made of a nonwoven or woven fabric made of conductive fibers. In this embodiment, carbon fibers are used as the conductive fibers in the sheet 43. However, the conductive fibers may be made of other materials, such as conductive metals like copper or nickel. The electrical resistance of the sheet 43 is lower than that of the rubber 42. Therefore, the sheet 43 has higher conductivity than the rubber 42.
[0034] In this embodiment, the sheet 43 further contains a synthetic resin as a binder. The binder is fixed to the surface of some of the conductive fibers contained in the sheet 43. The sheet 43 in this embodiment is a nonwoven or woven fabric made of conductive fibers with the binder fixed to it.
[0035] The sheet 43 integrally comprises an intermediate portion 44, a fixed portion 45, and a sliding portion 46. The fixed portion 45 is the part located radially outward (radially first side) of the metal ring 41. The sliding portion 46 is the part located radially inward (radially second side) of the metal ring 41. The intermediate portion 44 is the part located between the fixed portion 45 and the sliding portion 46.
[0036] The intermediate portion 44 of the sheet 43 has a first portion 44a, a second portion 44b, and a third portion 44c. The first portion 44a extends radially. As shown in Figures 3 and 4, the first portion 44a is positioned on the second axial side (bearing internal space K1 side) of the annular portion 41a of the metal ring 41 with a gap t1 between them.
[0037] The second portion 44b bends from the radially outer end of the first portion 44a to the second axial side and extends axially. Therefore, the second portion 44b is formed in a cylindrical shape. As shown in Figure 3, the second portion 44b is positioned radially inward of the cylindrical portion 41b of the metal ring 41 with a gap t2 between them.
[0038] The third portion 44c bends radially outward from the second axial end of the second portion 44b and extends radially. As shown in Figure 3, the third portion 44c is positioned at a gap t3 on the second axial side of the cylindrical portion 41b of the metal ring 41. Therefore, the intermediate portion 44 of the sheet 43 and the metal ring 41 are positioned at gaps t1, t2, and t3 throughout the radial direction.
[0039] The fixing portion 45 of the sheet 43 is formed in a continuous manner with the third portion 44c of the intermediate portion 44. As shown in Figure 3, the fixing portion 45 has a fourth portion 45a and a fifth portion 45b. The fourth portion 45a extends radially in a continuous manner from the radially outer end of the third portion 44c of the intermediate portion 44. The fifth portion 45b extends from the radially outer end of the fourth portion 45a, inclined toward the axial first side and radially outward. The tip of the fifth portion 45b constitutes the radially outer end of the sheet 43. The tip of the fifth portion 45b is in direct contact with the annular groove 23 of the outer ring 11. In this embodiment, the fourth portion 45a of the fixing portion 45 is also in direct contact with the annular groove 23. A part of the third portion 44c of the intermediate portion 44 is also in direct contact with the annular groove 23.
[0040] As shown in Figures 2 and 4, the sliding portion 46 of the sheet 43 is formed continuously with the first portion 44a, which is the intermediate portion 44. In this embodiment, the portion of the sheet 43 that is located radially inward from the radially inward end of the metal ring 41 is defined as the sliding portion 46. The sliding portion 46 extends linearly radially inward from the first portion 44a of the intermediate portion 44. Therefore, the first portion 44a of the intermediate portion 44 and the sliding portion 46 are formed as a whole in an annular shape perpendicular to the axial direction. The radially inward end 46a of the sliding portion 46 is in direct contact with the sliding member contact surface 33 of the inner ring 12. The radially inward end 46a of the sliding portion 46 is bent toward the first axial direction by contacting the sliding member contact surface 33.
[0041] As shown in Figure 2, the rubber 42 is bonded to the sheet 43 and the metal ring 41. The rubber 42 is provided over the entire axial first side (bearing external space K2 side) of the sheet 43. The rubber 42 has a first portion 42a, a second portion 42b, a third portion 42c, and a fourth portion 42d.
[0042] The first portion 42a of the rubber 42 is positioned at the intervals t1, t2, and t3 formed between the metal ring 41 and the sheet 43. The first portion 42a of the rubber 42 maintains the intervals t1, t2, and t3 between the metal ring 41 and the sheet 43 so that the metal ring 41 and the sheet 43 are not directly bonded together.
[0043] The second portion 42b of the rubber 42 is formed continuously on the radially outer side of the first portion 42a. The second portion 42b is located in the region enclosed by the fixing portion 45 of the sheet 43 and the cylindrical portion 41b of the metal ring 41. The second portion 42b of the rubber 42 elastically supports the fifth portion 45b of the sheet 43 from the radially inner side. The cylindrical portion 41b of the metal ring 41 supports the second portion 42b of the rubber 42 from the radially inner side. Therefore, the fixing portion (radially outer end) 45 of the sheet 43 is pressed against the annular groove 23 of the outer ring 11 by the elasticity of the second portion 42b of the rubber 42, which is supported by the cylindrical portion 41b of the metal ring 41, and is reliably brought into contact with the annular groove 23.
[0044] The third portion 42c of the rubber 42 extends radially inward from the radially inward end of the first portion 42a of the rubber 42, as shown in Figure 4. The third portion 42c is provided with substantially constant thickness along the axially first side surface of the sliding portion 46 of the sheet 43. The third portion 42c is formed in an annular shape perpendicular to the axial direction. The third portion 42c of the rubber 42 bends as the radially inward end 46a of the sliding portion 46 of the sheet 43 contacts the sliding member contact surface 33. It is elastically deformed and bent toward the first axial direction together with the sliding part 46.
[0045] The fourth portion 42d of the rubber 42 extends from the radially outer end of the third portion 42c, beyond the radially inner end of the metal ring 41, and is positioned on the axially first side surface of the metal ring 41. Thus, the fourth portion 42d has a substantially L-shaped cross-section and covers and adheres to the radially inner end surface and the axially second side surface of the annular portion 41a. The fourth portion 42d of the rubber 42 helps to firmly bond the rubber 42 to the metal ring 41 and prevents the rubber 42 from peeling off the metal ring 41.
[0046] Since the rubber 42 has higher rigidity than the sheet 43, the sheet 43 maintains its shape by the rubber 42. In addition, the middle portion 44 of the sheet 43 also maintains its shape by the metal ring 41.
[0047] The sheet 43 is made of a nonwoven or woven fabric formed of conductive fibers. In its material state before the manufacture of the sliding member 15, the sheet 43 contains voids inside. After the manufacture of the sliding member 15, the rubber 42 is also present in the voids of the sheet 43. As will be described later, the sliding member 15 is manufactured by inserting the metal ring 41 and the sheet 43 into a mold, vulcanizing the rubber material constituting the rubber 42, molding it into a predetermined shape, and bonding the rubber material to the metal ring 41 and the sheet 43. Hereinafter, this manufacturing process will also be referred to as "vulcanization bonding". During this vulcanization bonding, the rubber 42 enters the voids of the sheet 43. During vulcanization bonding, the rubber 42 is easily bonded to the binder.
[0048] The fixed portion 45 of the sheet 43 is exposed on the surface of the sliding member 15 and contacts the annular groove 23 of the outer ring 11. The sliding portion 46 of the sheet 43 is also exposed on the surface of the sliding member 15 and contacts the sliding member contact surface 33 of the inner ring 12. Since the multiple conductive fibers constituting the sheet 43 are in contact with each other, the sheet 43 is conductive from the fixed portion 45 to the sliding portion 46 due to the contact between the conductive fibers. Since the sheet 43 is in contact with the outer ring 11 and the inner ring 12, the outer ring 11 and the inner ring 12 are electrically connected via the sheet 43. In addition, the conductive metal ring 41 and rubber 42 are in contact with the sheet 43. The outer ring 11 and the inner ring 12 are electrically connected not only via the sheet 43 but also via the conductive metal ring 41 and rubber 42.
[0049] Therefore, the sliding member 15 of this embodiment can dissipate electric charge from one of the fixed portion 45 and the sliding portion 46 to the other. Furthermore, the sliding member 15 of this embodiment can dissipate electric charge from one of the member fixing the fixed portion 45 and the member on which the sliding portion 46 slides to the other. The rolling bearing 10 of this embodiment can dissipate electric charge from one of the outer ring 11 and the inner ring 12 to the other via the sliding member 15, thereby suppressing electrolytic corrosion of the balls 13 and the raceways 21 of the outer ring and 31 of the inner ring on which the balls 13 roll.
[0050] As shown in Figure 2, the seat 43 is positioned on the second axial side (bearing internal space K1 side) of the sliding member 15. On the other hand, the sliding member contact surface 33 formed on the inner ring 12 is a surface facing the first axial side (bearing external space K2 side). Therefore, the sliding portion 46 of the seat 43 is easily brought into contact with the sliding member contact surface 33. However, if the sliding member contact surface 33 is a surface facing the second axial side, the sliding member 15 may be formed such that the seat 43 is positioned on the first axial side of the sliding member 15.
[0051] [Manufacturing method for sliding members] Figure 5 is a cross-sectional view showing a part of the molding die for the sliding member. The sliding member 15 is manufactured by compression molding (pressure molding) using a mold. The molding die 50 for the sliding member 15 has an upper mold 51 and a lower mold 52. The upper mold 51 has a cavity 51a. The lower mold 52 has cavities 52a and 52b. Cavity 52b is formed to be further recessed from the bottom surface of cavity 52a.
[0052] The metal ring 41 is coated with adhesive on its surface. For example, the metal ring 41 is coated with adhesive by being immersed in the adhesive. The metal ring 41, the sheet 43, and the unvulcanized rubber material G are placed between the upper mold 51 and the lower mold 52 when they are separated and the mold 50 is open.
[0053] The cavity 51a of the upper mold 51 molds the second portion 42b and a part of the first portion 42a (around the cylindrical portion 41b of the metal ring 41) of the rubber 42 shown in Figure 2. The second portion 44b and the fixing portion 45 of the middle portion 44 of the sheet 43 fit into this cavity 51a, and the sheet 43 is molded to conform to the inner surface of the cavity 51a.
[0054] The cavity 52a of the lower mold 52 molds a portion of the first portion 42a (the portion excluding the cylindrical portion 41b of the metal ring 41) and a third portion 42c of the rubber 42 shown in Figure 2. A portion of the first portion 44a and the sliding portion 46 of the intermediate portion 44 of the sheet 43 enter the cavity 52a and are molded into a flat shape (see Figure 5) that follows the lower surface 51b of the upper mold 51. The cavity 52b of the lower mold 52 molds a fourth portion 42d of the rubber 42 shown in Figure 2.
[0055] The sliding member 15 is manufactured by placing the metal ring 41, the sheet 43, and the unvulcanized rubber material G between the upper mold 51 and the lower mold 52, closing the upper mold 51 and the lower mold 52, and then applying pressure and heating. The pressurized unvulcanized rubber material G flows within the mold. The unvulcanized rubber material G fills the cavities 51a, 52a, and 52b of the upper mold 51 and the lower mold 52. The unvulcanized rubber material G also fills the voids in the sheet 43. When heated in this state, the adhesive hardens, and the unvulcanized rubber material G becomes rubber 42. As the adhesive hardens and the unvulcanized rubber material G becomes vulcanized rubber 42, the metal ring 41, the sheet 43, and the rubber 42 become one unit. The unitized part is then trimmed of any unnecessary parts to become the sliding member 15. By impregnating the sheet 43 with the unvulcanized rubber material G and then vulcanizing it, the rigidity of the sheet 43 is increased, and the sheet 43 and the rubber 42 become one unit.
[0056] [Other embodiments] In the above embodiment, the rolling bearing 10 has a fixed outer ring 11 and a rotating inner ring 12. On the other hand, in the present invention, the outer ring 11 may be a rotating ring and the inner ring 12 may be a fixed ring.
[0057] In the above embodiment, the sliding member 15 is fixed to the outer ring 11, which is the first member, and is in slidable contact with the inner ring 12, which is the second member. On the other hand, in the present invention, the sliding member may be fixed to the inner ring 12, which is the first member, and be in slidable contact with the outer ring 11, which is the second member.
[0058] In the above embodiment, the sliding member 15 had a synthetic resin as a binder fixed to the conductive fibers constituting the sheet 43. On the other hand, in the sheet of the present invention, the conductive fibers constituting the sheet do not need to have a synthetic resin as a binder. In the above embodiment, the sliding member 15 was used in a rolling bearing 10. However, the sliding member 15 of the present invention may be used in a device in which it is fixed to one of two relatively moving members and slidably contacts the other member.
[0059] In the above embodiment, the case in which the rolling bearing 10 is a deep groove ball bearing was described. However, in the present invention, the rolling bearing 10 may be an angular contact ball bearing, or a roller bearing in which the rolling elements are rollers, etc.
[0060] The embodiments described above are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the embodiments, and includes all modifications within the scope of equivalence to the configurations described in the claims. [Explanation of Symbols]
[0061] 10: Rolling bearings 11: Outer ring 12: Inside 13: Rolling element 15: Sliding member 21: Outer ring track 31: Inner track 41: Metal ring 42: Rubber 42a: Part 1 42b: Part 2 42c: Part 3 42d: Part 4 43: Sheet 44: Middle section 45:Fixed part 46: Sliding part
Claims
1. A sheet which is a nonwoven or woven fabric formed of conductive fibers, A metal ring, Equipped with rubber, The aforementioned sheet is A fixing portion is fixed to the first member made of steel on the first radial side of the metal ring, A sliding portion that slidably contacts a second member made of steel on the second radial side, It integrally includes an intermediate portion located between the fixed portion and the sliding portion, The metal ring is positioned at a distance from the sheet on the first axial side, The rubber has first portions arranged at the aforementioned intervals, The rubber further comprises a second portion located on the first radial side of the first portion, and a third portion located on the second radial side of the first portion. A sliding member in which the first portion, the second portion, and the third portion are bonded to the entire axial first side of the sheet.
2. The sliding member according to claim 1, wherein the rubber has a fourth portion that extends beyond the radial end of the metal ring and is positioned on the first axial side of the metal ring.
3. An inner ring having an inner track, An outer ring having an outer ring raceway arranged radially outside the inner ring raceway, A plurality of rolling elements are arranged to be rotatable between the inner ring raceway and the outer ring raceway, The sliding member is disposed in the radial direction between the axial end of the inner ring and the axial end of the outer ring, as described in claim 1 or 2. One of the inner ring and the outer ring is the first member, A rolling bearing in which the other of the inner ring and the outer ring is the second member.
4. The rolling bearing according to claim 3, wherein in the axial direction, the sheet of the sliding member is positioned closer to the rolling element than the metal ring and the rubber.