Electrolytic corrosion preventing member for rolling bearing and electrolytic corrosion preventing rolling bearing unit

Abstract

To provide an electrolytic corrosion preventing member capable of suppressing generation of abrasion powder from a conductive member or abrasion powder due to sliding contact between the conductive member and a mating material, suppressing damage of the mating material, and coping with an existing bearing without forming new processing on the bearing and without limiting the type of the bearing.SOLUTION: An electric corrosion prevention member for a rolling bearing includes an annular portion, a spring plate including a plurality of elastic portions radially extending continuously from the annular portion, and a soft conductive member having a planar shape mounted on a surface of the elastic portion facing a rotary ring, wherein the annular portion is pressed against a side surface of a fixed ring by a pressing member, or the annular portion is sandwiched between a flange portion provided on a housing for fixing the fixed ring and the side surface of the fixed ring, so that the soft conductive member can be brought into contact with the side surface of the rotary ring, the spring plate is made of a thin plate of a conductive material, and the elastic portion is bent from a boundary with the annular portion only in a direction in which the soft conductive member is attached to the annular portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrolytic corrosion prevention member for a rolling bearing that is mounted to prevent electrolytic corrosion of the rolling bearing in a rolling bearing unit, and to an electrolytic corrosion prevention rolling bearing unit mounted with the electrolytic corrosion prevention member for a rolling bearing. [Background technology]

[0002] In recent years, electric vehicles that use electric motors as drive sources located inside or near the wheels to drive the wheels have become increasingly common. Such drive motors are generally called in-wheel motors. A typical in-wheel motor has a stator fixed to a motor housing, and a rotor located radially inside the stator with a gap between them, making it a so-called inner rotor motor. Furthermore, in consideration of motor performance and controllability, brushless DC motors driven by inverters are often used as the drive system for in-wheel motors.

[0003] In inverter-driven systems, a potential difference occurs between the stator and rotor due to factors such as parasitic capacitance between them. This potential difference generates what is known as a shaft voltage and current, and when this shaft current passes through the rolling bearing that supports the rotor, it causes damage to the rolling bearing, a phenomenon known as "electrical corrosion." Specifically, current flows locally at the contact points between the rolling surfaces of the outer and inner rings of the rolling bearing and the rolling elements, causing the raceway surface or rolling surface to melt and become uneven. This roughens the rolling surfaces and rolling element surfaces of the bearing, causing noise and vibration, and excessive electrical corrosion can also affect the bearing's lifespan.

[0004] In order to prevent electrolytic corrosion of rolling bearings, it has also been proposed to insert a conductive member. For example, Patent Documents 1 and 2 propose a bearing that is made up of a contact body for electrically connecting the bearing to the motor rotor, an elastic body for pressing the contact body toward the rotor, and a storage section for accommodating the contact body and the elastic body, with the storage section being provided in the motor housing and electrically connecting the bearing to the motor stator via the motor housing.

[0005] Furthermore, Patent Document 3 proposes an earthing device in which the tip of a broom-shaped conductive fiber is brought into contact with the outer circumferential surface of a rotating shaft.

[0006] Furthermore, Patent Document 4 proposes an electrolytic corrosion prevention device in which the annular seat that contacts the end face of the bearing outer ring is bent into a wave washer shape, and an elastic conductor is used that has a contact piece that extends from the inside of the annular seat and contacts the center of the end face of the rotating shaft, and the annular seat is overlapped with the end face of the bearing outer ring fitted into the bearing housing, and the contact piece is abutted against the center of the end face of the rotating shaft fitted into the bearing inner ring, and the surface of the annular seat is pressed with the lid-like wall of the bearing housing to establish electrical conductivity.

[0007] Furthermore, Patent Document 5 proposes that a rod-shaped conductive brush be housed in a support hole provided in one of the two raceways, and that an elastic member be used to urge the tip of the conductive brush toward the other raceway so that it slides against the other raceway, thereby establishing electrical continuity between the two raceways. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-135720 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-135722 [Patent Document 3] Japanese Patent Publication No. 2020-127257 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-146568 [Patent Document 5] Japanese Utility Model Application Publication No. 4-8820 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the techniques described in any of the patent documents, wear particles generated from the conductive member may contaminate the lubricating oil or grease composition sealed in the bearing for lubrication, potentially causing damage to the rolling surfaces or rolling contact surfaces.Furthermore, the mating material of the conductive member may be damaged, resulting in the generation of wear particles.

[0010] Specifically, in Patent Documents 1 and 2, the contact body, elastic body, and housing body are made of metal members, and metal powder is generated when these come into sliding contact with each other as the motor vibrates. In addition, the contact body, elastic body, and housing body must be provided in the motor housing, which requires space for them.

[0011] In addition, in Patent Document 3, the tips of the broom-shaped conductive fibers are brought into contact with the outer circumferential surface of the rotating shaft. However, in order to increase the contact area between the tips of the broom-shaped conductive fibers and the rotating shaft compared to when the tips are simply in contact, the broom-shaped conductive fibers are brought into contact with the outer circumferential surface of the rotating shaft in a bent state. In other words, the tips of the broom-shaped conductive fibers are in contact with the outer circumferential surface of the rotating shaft with a fairly strong pressing force, which generates wear powder. At the same time, the outer circumferential surface of the rotating shaft, which is the mating material of the broom-shaped conductive fibers, is also damaged.

[0012] In Patent Document 4, the elastic conductor and the rotating shaft are both made of metal, and metal powder is generated when they slide in contact with each other. At the same time, the end face of the rotating shaft, which is the mating material of the elastic conductor, is damaged.

[0013] In addition, in Patent Document 5, the tip of the rod-shaped conductive brush is biased and in contact with the other raceway, generating wear powder from the conductive brush. At the same time, the other raceway, which is the mating material of the conductive brush, is also damaged. Furthermore, a support hole must be formed in the raceway to accommodate the conductive brush and the elastic member, which places a heavy load on the raceway.

[0014] Therefore, the present invention aims to provide a space-saving, inexpensive electrolytic corrosion prevention member that suppresses the generation of wear powder from conductive members or wear powder caused by sliding contact between the conductive member and the mating material, and also suppresses damage to the mating material, without requiring any new processing on the bearing and without any restrictions on the type of bearing, making it compatible with existing bearings, as well as an electrolytic corrosion prevention rolling bearing unit equipped with the electrolytic corrosion prevention member. [Means for solving the problem]

[0015] The above object of the present invention is achieved by the following configuration [1] relating to an electrolytic corrosion prevention member for a rolling bearing.

[0016] [1] In a rolling bearing unit having a rolling bearing in which one raceway ring is a fixed raceway and the other raceway ring is a rotating raceway, an electrolytic corrosion prevention member is attached to the rolling bearing unit to prevent electrolytic corrosion of the rolling bearing, a spring plate made of a thin plate of a conductive material, the spring plate comprising a circular ring portion and a plurality of elastic portions extending radially from the circular ring portion; a soft conductive member attached to a surface of the elastic portion facing the rotating wheel; In addition to providing the soft conductive member is capable of abutting against a side surface of the rotating wheel; An electrolytic corrosion prevention member for a rolling bearing, comprising:

[0017] Further, preferred embodiments of the present invention relating to the electrolytic corrosion prevention member for a rolling bearing relate to the following [2] to [6].

[0018] [2] The electrolytic corrosion prevention member for a rolling bearing according to [1], characterized in that the annular portion is pressed against the side surface of the fixed ring via a spacer. [3] The electrolytic corrosion prevention member for a rolling bearing according to [1], characterized in that the soft conductive member is composed of at least one selected from a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body. [4] The electrolytic corrosion prevention member for a rolling bearing according to [2], characterized in that the soft conductive member is composed of at least one selected from a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body. [5] An anti-electrolytic corrosion member for a rolling bearing according to any one of [1] to [4], characterized in that the plurality of elastic portions of the spring plate are bent toward the rotating ring. [6] An anti-electrolytic corrosion member for a rolling bearing according to any one of [1] to [4], characterized in that the multiple elastic portions of the spring plate are formed flush with the annular portion.

[0019] The above object of the present invention is also achieved by the following configuration [7] relating to an electrolytic corrosion prevention member for a rolling bearing. [7] In a rolling bearing unit having a rolling bearing in which one raceway ring is a fixed raceway and the other raceway ring is a rotating raceway, an electrolytic corrosion prevention member is attached to the rolling bearing unit to prevent electrolytic corrosion of the rolling bearing, a spring plate made of a thin plate of a conductive material, the spring plate comprising a circular ring portion and a plurality of elastic portions extending radially from the circular ring portion; a soft conductive member attached to a surface of the elastic portion facing a rotating member into which the rotating wheel is fitted; In addition to providing the soft conductive member is capable of abutting against a side surface of the rotating member; An electrolytic corrosion prevention member for a rolling bearing, comprising:

[0020] Further, preferred embodiments of the present invention relating to the electrolytic corrosion prevention member for a rolling bearing relate to the following [8] to

[12] .

[0021] [8] The electrolytic corrosion prevention member for a rolling bearing according to [7], characterized in that the annular portion is pressed against the side surface of the fixed ring via a spacer. [9] The electrolytic corrosion prevention member for a rolling bearing according to [7], characterized in that the soft conductive member is composed of at least one selected from a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

[10] The electrolytic corrosion prevention member for a rolling bearing according to [8], characterized in that the soft conductive member is composed of at least one selected from a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

[11] An anti-electrolytic corrosion member for a rolling bearing according to any one of [7] to

[10] , characterized in that the plurality of elastic portions of the spring plate are bent toward the rotating ring.

[12] An anti-electrolytic corrosion member for a rolling bearing according to any one of [7] to

[10] , characterized in that the plurality of elastic portions of the spring plate are formed flush with the annular portion.

[0022] The above object of the present invention is achieved by the following configuration

[13] relating to an electrolytic corrosion prevention rolling bearing unit.

[0023]

[13] A rolling bearing having one raceway ring fixed and the other raceway ring rotating, An electrolytic corrosion prevention rolling bearing unit, characterized in that the electrolytic corrosion prevention member for a rolling bearing according to any one of [1] to

[12] is attached.

[0024] In the following description, the "electrolytic corrosion prevention member for a rolling bearing" will be simply referred to as the "electrolytic corrosion prevention member," and the "electrolytic corrosion prevention rolling bearing unit" will be simply referred to as the "bearing unit." [Effects of the Invention]

[0025] The electrolytic corrosion prevention member of the present invention comprises a soft conductive member attached to the elastic portion of a spring plate and abutting against the side surface of a rotating ring or a rotating member. The biasing force of the spring plate on the soft conductive member against the side surface of the rotating ring or a rotating member is not very strong, making it less likely to generate wear powder. Moreover, because the soft conductive member is a soft material, there is little damage to the rotating ring, which is the mating material.

[0026] Furthermore, since the spring plate does not require any processing on the rolling bearing and there is no restriction on the type of rolling bearing, it can be applied to existing rolling bearings, making it extremely versatile. Furthermore, the spring plate is a thin plate, which minimizes the increase in space required for the bearing unit to be installed.

[0027] The bearing unit of the present invention is fitted with the electrolytic corrosion prevention member of the present invention, which reduces the generation of wear powder and damage to the mating material, and is also highly versatile and does not require additional space. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 shows an example of application of an electrolytic corrosion prevention member according to the first embodiment of the present invention to an inner ring rotating type bearing unit, in which (A) is a plan view thereof, (B) is a cross-sectional view taken along line AA in (A), and (C) is an enlarged view showing the bending portion between the annular portion and the elastic portion in (B). [Figure 2] FIG. 2 is a cross-sectional view showing an example of a bearing unit to which the electrolytic corrosion prevention member shown in FIG. 1 is attached. [Figure 3] FIG. 3 is a diagram showing a state in which the electrolytic corrosion prevention member is pressed against the outer ring by a pressing member in FIG. [Figure 4] FIG. 4 shows an example of application of an electrolytic corrosion prevention member according to the second embodiment of the present invention to a bearing unit on the outer ring rotation side, where (A) is a plan view and (B) is a cross-sectional view taken along line AA of (A). [Figure 5] FIG. 5 is a cross-sectional view showing an example of a bearing unit to which the electrolytic corrosion prevention member shown in FIG. 4 is attached. [Figure 6]FIG. 6 is a diagram showing a state in which the electrolytic corrosion prevention member is pressed against the inner ring by a pressing member in FIG. [Figure 7] FIG. 7 is a cross-sectional view showing an example of an inner ring rotating type bearing unit equipped with an electrolytic corrosion prevention member according to a third embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view showing an example of an inner ring rotating type bearing unit equipped with another electrolytic corrosion prevention member according to the third embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view showing an example of an outer ring rotating type bearing unit equipped with an electrolytic corrosion prevention member according to a fourth embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view showing an example of an outer ring rotating type bearing unit equipped with another electrolytic corrosion prevention member according to the fourth embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view of a modified example of an electrolytic corrosion prevention member according to the present invention, corresponding to FIG. 1(B). [Figure 12] FIG. 12 is a cross-sectional view showing an example of a bearing unit to which the electrolytic corrosion prevention member shown in FIG. 11 is attached. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0030] (First embodiment: electrolytic corrosion prevention member for inner ring rotation and bearing unit) Fig. 1 shows an example of an electrolytic corrosion prevention member of the present invention that is applied when the rotating ring is an inner ring, Fig. 1(A) is a plan view thereof, Fig. 1(B) is a cross-sectional view taken along line AA of Fig. 1(A), and Fig. 1(C) is an enlarged view showing the bending portion between the annular portion and the elastic portion in Fig. 1(B). Fig. 2 is a cross-sectional view showing an example of a bearing unit of the present invention, to which the electrolytic corrosion prevention member shown in Fig. 1 is attached.

[0031] As shown in Fig. 1, the electrolytic corrosion prevention member 1A for inner ring rotation includes a spring plate 10A composed of an annular portion 11A and multiple elastic portions 13A that are bent at an inner diameter end 12A of the annular portion 11A and extend radially toward the center of the annular portion 11A. As shown in Fig. 2, the elastic portions 13A are bent toward the right in the drawing so as to face the inner ring 52 of the rolling bearing 50 when mounted on the bearing unit 100A. In addition, notches 15A are formed on both sides of the bent portion of the elastic portions 13A with the annular portion 11A, which maintain the bent state of the elastic portions 13A.

[0032] The spring plate 10A is made entirely of a thin plate made of a conductive material such as metal, and when the conductive material is metal, stainless steel is preferred because it is easy to process and is less likely to rust.

[0033] A soft conductive member 20 is attached to the surface of each elastic portion 13A facing the inner ring 52 of the rolling bearing 50, and the spring plate 10A and the soft conductive member 20 constitute the electrolytic corrosion prevention member 1A. The soft conductive member 20 is attached to the elastic portion 13A using an adhesive.

[0034] The soft conductive member 20 is a soft base material that has a conductive material mixed in or supported thereon. Examples of the soft base material include porous materials such as paper, cloth, and nonwoven fabric, and resin sheets. Examples of the conductive material include metal fibers, crushed materials, and powders of metals such as silver, copper, gold, aluminum, and stainless steel, or conductive carbon fibers, crushed materials, and powders. Commercially available soft conductive members, such as those labeled "conductive sheets," can also be used. Among these, the soft conductive member is preferably composed of at least one selected from the group consisting of resin-impregnated nonwoven fabrics, resin-impregnated nonwoven fabrics and woven fabrics, resin-impregnated soft porous materials such as woven fabrics and sponges, and soft porous materials such as sponges.

[0035] 1(C), the bending angle θ between the annular portion 11A and the elastic portion 13A is set appropriately according to the length (L) of the elastic portion 13A and the size of the soft conductive member 20 so that when mounted on the bearing unit 100A, the soft conductive member 20 abuts against the side surface 52a of the inner ring 52 of the rolling bearing 50. The bending angle θ can also be used to adjust the biasing force of the soft conductive member 20 on the side surface 52a of the inner ring 52 of the rolling bearing 50; the biasing force can be increased by reducing the bending angle θ, and conversely, the biasing force can be decreased by increasing the bending angle θ.

[0036] There is no limitation on the planar shape of the soft conductive member 20, and it may be a rectangular shape in addition to the sector shape shown in Fig. 1(A), or may be a plurality of small pieces.

[0037] As shown in Fig. 2, a bearing unit 100A is constructed by attaching the electrolytic corrosion prevention member 1A shown in Fig. 1 to a rolling bearing 50, but there are no limitations on the type of rolling bearing 50; a plurality of rolling elements (balls) 53 are held in a freely rollable manner by a cage 54 between an outer ring 51 and an inner ring 52, and are lubricated with a lubricating oil or grease composition. In this example, the rotating ring is the inner ring 52, and a shaft 60 directly connected to a motor (not shown) is fitted into the inner ring 52. The outer ring 51 is a fixed ring, and is fixed to a housing 70.

[0038] 3, in this embodiment, the annular portion 11A of the electrolytic corrosion prevention member 1A is pressed against the side surface of the outer ring 51 by the conductive pressing member 80 via the conductive spacer 30. The thickness of the spacer 30 may be determined taking into consideration the pressing force of the spring plate 10A, the thickness of the soft conductive member 20, etc. The annular portion 11A of the electrolytic corrosion prevention member 1A may also be in direct contact with the side surface of the outer ring 51 without providing the spacer 30.

[0039] In this type of inner ring rotating type bearing unit 100A, current from the motor normally flows through the shaft 60 to the inner ring 52, conducting current through the interior of the bearing to the rolling elements 53 and outer ring 51, causing electrolytic corrosion in the rolling bearing 50. Therefore, in the present invention, the electrolytic corrosion prevention member 1A is mounted in the housing 70 so that the soft conductive member 20 abuts against the side surface 52a of the inner ring 52. Furthermore, the annular portion 11A of the spring plate 10A is in electrical contact with the side surface of the outer ring 51 via the conductive spacer 30, and is also in electrical contact with the conductive pressing member 80.

[0040] As a result, the current from the shaft 60 flows through the soft conductive member 20 via the inner ring 52 to the elastic portion 13A and annular portion 11A of the spring plate 10A, and then flows to the housing 70 via the outer peripheral end surface 14A of the annular portion 11A, the pressing member 80, the spacer 30 and the outer ring 51, so that no current flows inside the bearing and the rolling bearing 50 does not suffer from electrolytic corrosion. Since the outer ring 51 has a large contact area with the housing 70, the current flowing through the outer ring 51 does not pass through the rolling elements 53 but flows to the housing 70. In addition, in this embodiment, the outer peripheral end surface 14A of the annular portion 11A and the spacer 30 abut against the housing 70, but they may be configured not to abut against the housing 70 but to be sandwiched between the outer ring 51 and the pressing member 80. In this case, the current flowing through the annular portion 11A flows to the housing 70 via the outer ring 51 and the pressing member 80. Furthermore, the annular portion 11A of the electrolytic corrosion prevention member 1A may be pressed directly against the side surface of the outer ring 51 via the conductive spacer 30, without providing the pressing member 80, and may be fixed in contact with the housing .

[0041] Furthermore, since the side surface 52a of the inner ring 52 is in contact with the soft conductive member 20, the side surface 52a of the inner ring 52 is not damaged, and a decrease in the rotational torque of the inner ring 52 can be prevented. Moreover, the base material of the soft conductive member 20 is porous and has oil absorption and oil retention properties, so oil is easily discharged between adjacent spring plates 10A when the shaft rotates and an oil film is unlikely to form, providing good conductivity even when used in oil. Furthermore, by using a porous base material for the soft conductive member 20, the coefficient of friction is reduced even when used in environments other than oil, and a decrease in the rotational torque of the inner ring 52 can be prevented.

[0042] Furthermore, the spring plate 10A of the electrolytic corrosion prevention member 1A is a thin plate, which minimizes the increase in space required for the bearing unit 100A. In addition, there are no restrictions on the rolling bearing 50 and no processing is required, so it can be applied to existing rolling bearings and is extremely versatile.

[0043] Increasing the contact area between the soft conductive member 20 of the electrolytic corrosion prevention member 1A and the side surface 52a of the inner ring 52 of the rolling bearing 50 makes it possible to more effectively prevent electrolytic corrosion of the rolling bearing 50. Because the spring plate 10A is an elastic member made entirely of a curved thin plate, when the annular portion 11A of the electrolytic corrosion prevention member 1A is pressed against the outer ring 51, the elastic force caused by the pressing acts on the elastic portion 13A, which is pushed out so that the bending angle θ shown in FIG. 1(C) increases, and the entire elastic portion 13A moves toward the rolling bearing 50. Accordingly, the portion of the soft conductive member 20 that was away from the side surface 52a of the inner ring 52 in FIG. 2 also moves toward the rolling bearing 50, and almost the entire soft conductive member 20 comes into contact with the side surface 52a of the inner ring 52.

[0044] (Second embodiment: electrolytic corrosion prevention member for outer ring rotation and bearing unit) Although the above description has been given of the case where the inner ring 52 of the rolling bearing 50 is the rotating ring, the outer ring 51 may also be the rotating ring. Fig. 4 shows an electrolytic corrosion prevention member for outer ring rotation, with Fig. 4(A) being its plan view and Fig. 4(B) being a cross-sectional view taken along line AA of Fig. 4(A). Fig. 5 shows a bearing unit equipped with the electrolytic corrosion prevention member shown in Fig. 4.

[0045] As shown in Fig. 4, the outer ring rotation electrolytic corrosion prevention member 1B includes a spring plate 10B composed of an annular portion 11B and a plurality of elastic portions 13B that are bent at an outer diameter side end 12B of the annular portion 11B and extend radially from the center of the annular portion 11B toward the outer periphery. As shown in Fig. 5, the elastic portions 13B are bent toward the right in the drawing so as to face the outer ring 51 of the rolling bearing 50 when mounted on the bearing unit 100B. In addition, arc-shaped notches 15B are formed on both sides of the bent portion of the elastic portions 13B with the annular portion 11B.

[0046] A soft conductive member 20 is attached to the surface of each elastic portion 13B facing the outer ring 51 of the rolling bearing 50, and the spring plate 10B and the soft conductive member 20 form the electrolytic corrosion prevention member 1B. The soft conductive member 20 is the same as the electrolytic corrosion prevention member 1A described above, and a description thereof will be omitted.

[0047] 5, the rolling bearing 50 has the inner ring 52 fixed to the fixed member 75 and the outer ring 51 fitted with the rotating member 65. The electrolytic corrosion prevention member 1B is attached to the fixed member 75 so that the soft conductive member 20 abuts against the side surface 51a of the outer ring 51.

[0048] Current from the motor (not shown) that drives the rotating member 65 flows into the outer ring 51, but it flows from the soft conductive member 20 through the outer ring 51 to the elastic portion 13B and annular portion 11B of the spring plate 10B, and then to the fixed member 75 via the inner end face 14B of the annular portion 11B, the pressing member 80, the spacer 30 and the inner ring 52, so no current flows inside the bearing and the rolling bearing 50 does not suffer from electrolytic corrosion.

[0049] Furthermore, as shown in FIG. 6, the annular portion 11B of the electrolytic corrosion prevention member 1B is pressed against the inner ring 52 by the pressing member 80, thereby increasing the contact area between the soft conductive member 20 and the side surface 51a of the outer ring 51, thereby more effectively preventing electrolytic corrosion of the rolling bearing 50.

[0050] In this embodiment as well, the annular portion 11B of the electrolytic corrosion prevention member 1B may directly contact the side surface of the inner ring 52 without providing the spacer 30. Furthermore, the inner peripheral end surface 14B of the annular portion 11B and the spacer 30 may be in contact with the fixing member 75, or may not be in contact with the fixing member 75 but may be clamped between the inner ring 52 and the fixing member 75 by the pressing member 80.

[0051] (Third embodiment: electrolytic corrosion prevention member for inner ring rotation and bearing unit) 7 shows a case where an electrolytic corrosion prevention member is mounted on a bearing unit in which the rotating ring is an inner ring, as in the first embodiment. In this case, a shaft 60, which is a rotating member into which the inner ring 52 is fitted, is formed with a stepped surface 60c having a smaller diameter than a fitting surface 60b into which the inner ring 52 is fitted.

[0052] The soft conductive member 20 of the spring plate 10A is attached to the surface of the elastic part 13A that faces the shaft 60 in the axial direction, specifically, to the side surface 60a between the fitting surface 60b, where the inner ring 52 fits, and the step surface 60c, by elastically deforming the elastic part 13A. Therefore, the soft conductive member 20 can abut against the side surface 60a of the shaft 60.

[0053] In this type of inner ring rotating type bearing unit 100A, the soft conductive member 20 of the electrolytic corrosion prevention member 1A is attached to the housing 70 so that it abuts against the side surface 60a of the shaft 60. The annular portion 11A of the spring plate 10A is in electrical contact with the side surface of the outer ring 51 via the conductive spacer 30, and is also in electrical contact with the end face of the flange portion 71 of the housing 70.

[0054] As a result, the current from the shaft 60 flows from the soft conductive member 20 through the side surface 60a of the shaft 60 to the elastic portion 13A and annular portion 11A of the spring plate 10A, and then flows to the housing 70 via the outer peripheral end face 14A of the annular portion 11A, the spacer 30 and the outer ring 51, or directly to the housing 70, so that no current flows inside the bearing and the rolling bearing 50 does not suffer from electrolytic corrosion.

[0055] Unlike the first embodiment, this embodiment allows for greater design freedom for the rolling bearing, such as the attachment of a snap ring, because the electrolytic corrosion prevention member 1A does not come into contact with the side surface 52a of the inner ring 52. Furthermore, in this embodiment, the electrolytic corrosion prevention member and the rolling bearing are positioned apart, making it possible to separately control the lubrication environments for each. For example, it is possible to create a dry environment for just the electrolytic corrosion prevention member, or to increase or decrease the amount of oil lubrication for the electrolytic corrosion prevention member and the rolling bearing.

[0056] In particular, in the bearing unit 100A shown in Figure 7, the position where the soft conductive member 20 contacts the side surface 60a of the shaft 60 has a smaller diameter than the position where it contacts the side surface 52a of the inner ring 52 as shown in Figure 1, so the circumferential speed of the side surface 60a of the shaft 60 can be reduced, and the generation of wear powder and drag loss can be further suppressed.

[0057] As shown in FIG. 8, in this embodiment, the shaft 60 may be provided with a flange portion 62 that protrudes radially outward from the fitting surface 60b, and the soft conductive member 20 may be in contact with a side surface 60a of this flange portion 62.

[0058] (Fourth embodiment: electrolytic corrosion prevention member for outer ring rotation and bearing unit) 9 shows a case where an electrolytic corrosion prevention member is attached to a bearing unit in which the rotating ring is an outer ring, as in the second embodiment. In this case, a rotating member 65 into which the outer ring 51 is fitted is formed with a step surface 65c having a larger diameter than a fitting surface 65b into which the outer ring 51 is fitted.

[0059] The soft conductive member 20 of the spring plate 10B is attached to a surface of the elastic portion 13B that faces the rotating member 65 in the axial direction, specifically, to a side surface 65a between a fitting surface 65b that fits with the outer ring 51 and a step surface 65c, by elastically deforming the elastic portion 13B. Therefore, the soft conductive member 20 can abut against the side surface 65a of the rotating member 65.

[0060] In this outer ring rotating type bearing unit 100B, the soft conductive member 20 of the electrolytic corrosion prevention member 1B is attached to the rotating member 65 so as to abut against the side surface 65a of the rotating member 65. The annular portion 11B of the spring plate 10B is in electrical contact with the side surface of the inner ring 52 via the conductive spacer 30, and is also in electrical contact with the end surface of the flange portion 76 of the fixed member 75.

[0061] As a result, current from the motor (not shown) that drives the rotating member 65 flows from the soft conductive member 20 through the side surface 65a of the rotating member 65 to the elastic portion 13B and annular portion 11B of the spring plate 10B, and then flows via the inner end face 14B of the annular portion 11B, the spacer 30 and the inner ring 52 to the fixed member 75, or directly to the fixed member 75, so that no current flows inside the bearing and the rolling bearing 50 does not suffer from electrolytic corrosion.

[0062] Unlike the second embodiment, this embodiment allows for greater design freedom for the rolling bearing, such as the attachment of a snap ring, because the electrolytic corrosion prevention member 1B does not come into contact with the side surface 51a of the outer ring 51. Furthermore, in this embodiment, the electrolytic corrosion prevention member and the rolling bearing are positioned apart, making it possible to separately control the lubrication environments for each. For example, it is possible to create a dry environment for just the electrolytic corrosion prevention member, or to increase or decrease the amount of oil lubrication for the electrolytic corrosion prevention member and the rolling bearing.

[0063] As shown in FIG. 10, in this embodiment, the rotating member 65 may be provided with a flange portion 67 that protrudes from the fitting surface 65b toward the inner diameter side, and the soft conductive member 20 may be made to abut against the side surface 65a of this flange portion 67.

[0064] In particular, in the bearing unit 100B shown in Figure 10, the position where the soft conductive member 20 contacts the side surface 65a of the rotating member 65 has a smaller diameter than the position where it contacts the side surface 51a of the outer ring 51 as shown in Figure 6, so the circumferential speed of the side surface 65a of the rotating member 65 can be reduced, and the generation of wear powder and drag loss can be further suppressed.

[0065] The present invention is not limited to the above-described embodiment, and can be modified and improved as appropriate. For example, in the above embodiment, the multiple elastic portions 13A, 13B of the spring plates 10A, 10B are configured to be bent toward the rotating ring, but they may be configured to be formed flush with the annular portions 11A, 11B without being bent at the inner diameter side end 12A and the outer diameter side end 12B. As shown in Fig. 11, for example, in the case of an electrolytic corrosion prevention member 1A for inner ring rotation, the annular portion 11A and the elastic portion 13A are continuous in a straight line in a side view.

[0066] 12, when the annular portion 11A of the electrolytic corrosion prevention member 1A is sandwiched between the flange portion 71 of the housing 70 and the side surface of the outer ring 51, the elastic portion 13A of the electrolytic corrosion prevention member 1A elastically deforms by an amount corresponding to the thickness of the soft conductive member 20, and the bending reaction force of the spring plate 10A causes the soft conductive member 20 to abut against the side surface of the inner ring 52. This allows the bearing unit 100A to achieve the same function as the above embodiment.

[0067] In this case, bending of the spring plate 10A is not required, so the electrolytic corrosion prevention member 1A can be manufactured at low cost, and the spring plate 10A and the soft conductive member 20 can be easily bonded to each other.

[0068] In addition, in this embodiment, the spring plate is configured to have multiple elastic portions extending radially toward the center of the annular portion, but it may also be configured to have a single elastic portion extending toward the center of the annular portion. [Explanation of symbols]

[0069] 1A, 1B Electrolytic corrosion prevention material 10A, 10B spring plate 11A, 11B Circular part 12A Inner diameter end 12B Outer diameter end 13A, 13B Elastic part 14A Outer periphery end face 14B Inner peripheral end face 15A, 15B notch 20 Soft conductive material 30 spacer 50 bearings 51 outer ring 51a,52a side 52 Inner circle 53 Rolling elements 54 Cage 60 shaft 65 Rotating members 70 Housing 75 Fixing member 80 Retaining member 100A, 100B bearing unit

Claims

1. In a rolling bearing unit having a rolling bearing in which one raceway ring is a fixed raceway and the other raceway ring is a rotating raceway, an electrolytic corrosion prevention member is attached to the rolling bearing unit to prevent electrolytic corrosion of the rolling bearing, a spring plate including a circular ring portion and a plurality of elastic portions extending radially from the circular ring portion; a soft conductive member having a planar shape attached to a surface of the elastic portion facing the rotating wheel; In addition to providing The annular portion is pressed against the side surface of the fixed ring by a pressing member, or the annular portion is sandwiched between a flange portion provided on a housing for fixing the fixed ring and the side surface of the fixed ring, the soft conductive member is capable of contacting a side surface of the rotating wheel; the spring plate is made of a thin plate of conductive material; the elastic portion bends from the boundary with the annular portion only in a direction in which the soft conductive member is attached to the annular portion. An electrolytic corrosion prevention member for a rolling bearing, comprising:

2. 2. The electrolytic corrosion prevention member for a rolling bearing according to claim 1, wherein the annular portion is pressed against the side surface of the fixed ring via a spacer.

3. 2. The electrolytic corrosion prevention member for a rolling bearing according to claim 1, characterized in that the soft conductive member is composed of at least one selected from a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

4. 3. The electrolytic corrosion prevention member for a rolling bearing according to claim 2, characterized in that the soft conductive member is composed of at least one selected from the group consisting of a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

5. In a rolling bearing unit having a rolling bearing in which one raceway ring is a fixed raceway and the other raceway ring is a rotating raceway, an electrolytic corrosion prevention member is attached to the rolling bearing unit to prevent electrolytic corrosion of the rolling bearing, a spring plate including a circular ring portion and a plurality of elastic portions extending radially from the circular ring portion; a soft conductive member having a planar shape attached to a surface of the elastic portion facing a rotating member into which the rotating wheel is fitted; In addition to providing the soft conductive member is capable of abutting against a side surface of the rotating member, the spring plate is made of a thin plate of conductive material; the elastic portion bends from the boundary with the annular portion only in a direction in which the soft conductive member is attached to the annular portion. An electrolytic corrosion prevention member for a rolling bearing, comprising:

6. 6. The electrolytic corrosion prevention member for a rolling bearing according to claim 5, wherein the annular portion is pressed against a side surface of the fixed ring via a spacer.

7. 6. The electrolytic corrosion prevention member for a rolling bearing according to claim 5, characterized in that the soft conductive member is composed of at least one selected from the group consisting of a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

8. 7. The electrolytic corrosion prevention member for a rolling bearing according to claim 6, characterized in that the soft conductive member is composed of at least one selected from the group consisting of a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, a resin-impregnated soft porous body, and a soft porous body.

9. A rolling bearing is provided in which one raceway ring is a fixed ring and the other raceway ring is a rotating ring, An electrolytic corrosion prevention rolling bearing unit, characterized in that the electrolytic corrosion prevention member for a rolling bearing according to any one of claims 1 to 8 is mounted thereon.

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