Shaft grounding member and rolling bearing unit for rolling bearings

Abstract

The present invention provides a shaft grounding member and a rolling bearing unit equipped with the shaft grounding member, which suppress the generation of wear particles from conductive members or wear particles associated with the sliding contact between conductive members and mating materials, as well as suppress damage to the mating material, and which can stably ensure excellent conductivity, prevent creep in rolling bearings, do not require any new processing to be formed on the bearing, are not limited to the type of bearing and can be used with existing bearings, and furthermore can stably ensure conductivity with the fixed ring and the fixed member into which the fixed ring is fitted. [Solution] The shaft grounding member for a rolling bearing comprises a spring plate composed of an annular portion and one or more elastic portions extending radially from the annular portion, and a soft conductive member mounted on the surface of the elastic portion facing the rotating wheel, the soft conductive member being able to contact the side surface of the rotating wheel. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the portion of the annular portion facing the side surface of the stationary wheel, and which apply a pressing force to the stationary wheel by deforming themselves.

Description

Technical Field

[0004] , , , ,

[0003]

[0001] The present invention relates to a shaft grounding member for a rolling bearing, which is mounted to prevent the occurrence of electrical erosion or electromagnetic noise in a rolling bearing in a rolling bearing unit, and a rolling bearing unit equipped with the shaft grounding member for a rolling bearing.

Background Art

[0002] In recent years, the practical application of electric vehicles that drive wheels by arranging an electric motor as a drive source inside or near the wheels has been progressing. Such a drive motor is generally called an in-wheel motor. The structure of a general in-wheel motor is such that a stator (stator) is fixed to a motor housing, and a rotor (rotor) is arranged with a gap in the radial direction on the inner diameter side of the stator, which is a so-called inner rotor type motor. Further, as a drive method of an in-wheel motor, a brushless DC motor driven by an inverter is widely used in consideration of the performance and control performance of the motor.

[0003] In a driving method using an inverter, a potential difference occurs between the stator and the rotor due to a parasitic capacitance or the like between the stator and the rotor. Due to this potential difference, so-called shaft voltage and shaft current are generated. When this shaft current passes through a rolling bearing that supports the rotor, a phenomenon called "electrical erosion" that damages the rolling bearing occurs. Specifically, current flows locally at the contact portions between the rolling surfaces of the outer ring and inner ring of the rolling bearing and the rolling elements, and the raceway surface or rolling surface melts or the like to form irregularities, whereby the rolling surface and the surface of the rolling elements of the bearing become rough, which not only causes noise and vibration, but also affects the life of the bearing when excessive electrical erosion occurs.

[0004] In order to prevent electrical erosion of the rolling bearing, a conductive member is also interposed. For example, in Patent Documents 1 and 2, it is composed of a contact body for electrically connecting to the rotor of the motor, an elastic body for pressing the contact body toward the rotor side, and a storage portion for housing the contact body and the elastic body. It is proposed to provide the storage portion in the motor housing and electrically connect to the motor stator through 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 surface of a rotating shaft.

[0006] Furthermore, Patent Document 4 proposes an electrolytic corrosion prevention device in which an annular seat portion that contacts the end face of the bearing outer ring is bent into a wave washer shape, and an elastic conductor having a contact piece that extends from the inside of the annular seat portion and contacts the vicinity of the center of the end face of the rotating shaft is used, and the annular seat portion is superimposed on the end face of the bearing outer ring fitted into the bearing housing, and the contact piece is in contact with the vicinity of the center of the end face of the rotating shaft fitted into the bearing inner ring, and the surface of the annular seat portion is pressed by the lid-shaped wall of the bearing housing to make it electrically conductive.

[0007] Furthermore, Patent Document 5 proposes housing a rod-shaped conductive brush in a support hole provided in one of the two raceway rings, and using an elastic member to bias the tip of the conductive brush toward the other raceway ring, thereby electrically connecting the two raceway rings.

[0008] Patent Document 6 proposes providing a carbon filament shaft grounding brush with its tip in contact with the extension shaft to ground and remove the shaft voltage generated on the shaft, thereby preventing electrolytic corrosion that occurs in the bearing.

[0009] Incidentally, bearings require measures to counter electromagnetic noise generated by electromagnetic interference, and various devices have been proposed to suppress the generation of electromagnetic noise. For example, Patent Document 7 proposes housing a conductive rod-shaped carbon brush between an inner ring and a metal ring, and biasing the tip of the carbon brush, which is attached to the metal ring by a spring, against the inner ring to bring it into sliding contact. This imparts conductive properties to the conductive bearing and also allows the current flowing through the conductive bearing to flow out of the system via the metal ring and brush, thereby eliminating electromagnetic noise.

[0010] Patent Document 8 proposes a conductive device that can dissipate electromagnetic noise by suppressing the formation of an oil film between a conductive rubber lip and a metal housing attached to a rotating shaft using centrifugal force, or by controlling the thickness of the oil film. By suppressing the formation of the oil film or reducing its thickness, the electrical resistance of the oil film is reduced, making it possible to dissipate electromagnetic noise from the rotating shaft to the housing.

[0011] Patent Document 9 proposes improving electromagnetic noise prevention and electrolytic corrosion prevention by ensuring a path for electric charge by having conductive rolling elements roll between the outer and inner rings while the oil film is broken, thereby significantly reducing the impedance between the outer and inner rings, or the entire bearing.

[0012] Patent Document 10 proposes an electromagnetic noise suppression device that electrically connects the metal case of the electric motor and the rotating shaft inside the electric motor using conductive means such as a sliding contact member, thereby diverting electromagnetic noise induced on the rotating shaft to a metal electric motor housing grounded to the vehicle body. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] Japanese Patent Publication No. 2011-135720 [Patent Document 2] Japanese Patent Publication No. 2011-135722 [Patent Document 3] Japanese Patent Publication No. 2020-127257 [Patent Document 4] Japanese Patent Publication No. 2002-146568 [Patent Document 5] Japanese Utility Model Publication No. 4-8820 [Patent Document 6] Japanese Patent Publication No. 2017-060401 [Patent Document 7] Japanese Patent Publication No. 2024-130948 [Patent Document 8] Japanese Patent Publication No. 2023-018214 [Patent Document 9] Japanese Patent Publication No. 2022-139252 [Patent Document 10] Japanese Patent Publication No. 2000-244180 [Overview of the Initiative] [Problems that the invention aims to solve]

[0014] However, in all the technologies described in the patent documents, wear particles generated from the conductive member may contaminate the lubricating oil or grease composition sealed inside for lubrication, potentially damaging the rolling surface. Furthermore, the conductive member may damage the mating material, generating wear particles from that material as well.

[0015] To explain in more detail, in Patent Documents 1 and 2, the contact body, elastic body, and housing are made of metal, and metal powder is generated when these slide against each other due to the vibration of the motor. In addition, the contact body, elastic body, and housing need to be installed in the motor housing, and space is required for this.

[0016] Furthermore, in Patent Document 3, the tip of the broom-shaped conductive fiber is brought into contact with the outer surface of the rotating shaft. However, in order to increase the contact area between the tip of the broom-shaped conductive fiber and the rotating shaft compared to simply bringing them into contact, the broom-shaped conductive fiber is brought into contact with the outer surface of the rotating shaft in a bent state. That is, the tip of the broom-shaped conductive fiber is in contact with the outer surface of the rotating shaft with a certain degree of strong pressure, and wear particles are generated. At the same time, the outer surface of the rotating shaft, which is the mating material of the broom-shaped conductive fiber, is also damaged.

[0017] Furthermore, in Patent Document 4, both the elastic conductor and the rotating shaft are made of metal, and metal powder is generated when the two come into contact. At the same time, the end face of the rotating shaft, which is the mating material of the elastic conductor, is damaged.

[0018] In Patent Document 5, since the tip of the rod-shaped conductive brush is in contact with the other track wheel in a biased state, wear powder of the conductive brush is generated. At the same time, the other track wheel, which is the mating material of the conductive brush, is also damaged. Furthermore, it is necessary to form a support hole for accommodating the conductive brush and the elastic member in the track wheel, which imposes a large load on the track wheel.

[0019] In Patent Document 6, since the tip of the shaft grounding brush made of carbon filament is provided to abut against the extension shaft, wear powder of the shaft grounding brush is generated. At the same time, the extension shaft, which is the mating material of the shaft grounding brush, is also damaged.

[0020] Furthermore, in the bearings shown in Patent Documents 1 to 9, frictional heat may be generated due to the sliding contact between the conductive member and the mating material during use, which reduces the durability of the bearing. In addition, with the recent improvement in the performance of motors, the peripheral speed of the rotating member has also increased, so further suppression of temperature rise is required.

[0021] Regarding Patent Document 10, although a wear-resistant member is selected as the sliding contact member, the effect of reducing wear is not sufficient.

[0022] Furthermore, when a different material from the bearing material such as aluminum is used for the housing or the rotating shaft as the fixing member into which the fixed ring is fitted, creep or loosening of the fit may occur between the fixed ring and the fixing member due to temperature changes. In such an environment where creep or loosening of the fit may occur, even when a conductive member is used, it is required to ensure the electrical contact of the conductive member and obtain stable conductivity.

[0023] Therefore, the present invention aims to provide a shaft grounding member and a rolling bearing unit equipped with the shaft grounding member that suppress the generation of wear particles from a conductive member or wear particles associated with the sliding contact between a conductive member and a mating material, as well as suppress damage to the mating material, in addition to stably ensuring excellent conductivity, preventing creep in rolling bearings, and without forming new processing on the bearing, and without restrictions on the type of bearing, and can be used with existing bearings, and is space-saving and inexpensive. [Means for solving the problem]

[0024] The above objective of the present invention is achieved by the configuration described below [1] relating to the shaft grounding member for rolling bearings.

[0025] [1] A shaft grounding member to be mounted on a rolling bearing unit which has a rolling bearing in which one raceway is a fixed wheel and the other raceway is a rotating wheel, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating wheel, In addition to being equipped, The aforementioned flexible conductive member is capable of contacting the side surface of the rotating wheel. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A shaft grounding member for rolling bearings characterized by the following.

[0026] Furthermore, preferred embodiments of the present invention relating to shaft grounding members for rolling bearings are described in the following [2] to [9].

[0027] [2] Each of the bent portions is a cut-out piece formed by folding in the axial direction between a pair of notches cut out from the periphery of the annular portion. [1] The shaft grounding member for rolling bearings.

[0028] [3] The plurality of bent portions have a portion between a pair of notches cut out from the periphery of the annular portion that is bent in one direction in the axial direction and a portion that is bent in the other direction in the axial direction. [1] The shaft grounding member for rolling bearings.

[0029] [4] Each of the bent portions is a portion between a pair of notches cut out from the periphery of the annular portion, or a folded piece formed by folding back in the axial direction a portion extending radially from the periphery of the annular portion. [1] The shaft grounding member for rolling bearings.

[0030] [5] The plurality of bent portions have a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion, which has one folded piece folded back to one side in the axial direction and the other folded piece folded back to the other side in the axial direction. [1] The shaft grounding member for rolling bearings.

[0031] [6] The annular portion is pressed against the side surface of the fixed ring with a spacer in between. A shaft grounding member for rolling bearings as described in any one of [1] to [5].

[0032] [7] The soft conductive member is a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, It consists of at least one selected from a resin-impregnated soft porous material and a soft porous material. A shaft grounding member for rolling bearings as described in any one of [1] to [6].

[0033] [8] The plurality of elastic parts of the spring plate are bent toward the rotating wheel, A shaft grounding member for rolling bearings as described in any one of [1] to [7].

[0034] [9] The plurality of elastic portions of the spring plate are formed flush with the annular portion, A shaft grounding member for rolling bearings as described in any one of [1] to [7].

[0035] Furthermore, the above objective of the present invention is achieved by the configuration of the following

[10] relating to the shaft grounding member for rolling bearings.

[0036]

[10] A shaft grounding member to be mounted on a rolling bearing unit having a rolling bearing in which one raceway is a fixed wheel and the other raceway is a rotating wheel, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating member into which the rotating ring is fitted, In addition to being equipped, The soft conductive member is capable of contacting the side surface of the rotating member. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A shaft grounding member for rolling bearings characterized by the following.

[0037] Furthermore, preferred embodiments of the present invention relating to shaft grounding members for rolling bearings are described in the following

[11] to

[18] .

[0038]

[11] Each of the bent portions is a cut-out piece formed by folding in the axial direction between a pair of notches cut out from the periphery of the annular portion.

[10] The shaft grounding member for rolling bearings.

[0039]

[12] The plurality of bent portions each have one cut-out piece where the portion between a pair of notches cut out from the periphery of the annular portion is bent in one axial direction, and the other cut-out piece which is bent in the other axial direction.

[10] The shaft grounding member for rolling bearings.

[0040]

[13] Each of the bent portions is a portion between a pair of notches cut out from the periphery of the annular portion, or a folded piece formed by folding back in the axial direction a portion extending radially from the periphery of the annular portion.

[10] The shaft grounding member for rolling bearings.

[0041]

[14] The plurality of bent portions have one folded piece which is folded back in one axial direction and the other folded piece which is folded back in the axial direction and the portion which is folded back in one axial direction and the portion which is cut out from the periphery of the annular portion, or the portion which extends radially from the periphery of the annular portion.

[10] The shaft grounding member for rolling bearings.

[0042]

[15] The annular portion is pressed against the side surface of the fixed ring with a spacer in between. A shaft grounding member for rolling bearings as described in any one of

[10] to

[14] .

[0043]

[16] The flexible 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 flexible porous body, and a flexible porous body. A shaft grounding member for rolling bearings as described in any one of

[10] to

[15] .

[0044]

[17] The plurality of elastic parts of the spring plate are bent toward the rotating wheel, A shaft grounding member for rolling bearings as described in any one of

[10] to

[16] .

[0045]

[18] The plurality of elastic portions of the spring plate are formed flush with the annular portion, A shaft grounding member for rolling bearings as described in any one of

[10] to

[16] .

[0046] The above objective of the present invention is achieved by the following configuration

[19] relating to a rolling bearing unit.

[0047]

[19] A rolling bearing is provided in which one raceway is a fixed ring and the other raceway is a rotating ring, A rolling bearing unit characterized by being fitted with a rolling bearing shaft grounding member described in any one of [1] to

[18] .

[0048] Hereafter, "shaft grounding member for rolling bearings" will simply be referred to as "shaft grounding member," and "rolling bearing unit" will simply be referred to as "bearing unit." [Effects of the Invention]

[0049] In this invention, the spring plate of the shaft grounding member is provided with multiple bent portions that are bent axially in the annular portion facing the side surface of the fixed ring and apply a pressing force between itself and the fixed ring by deforming. Therefore, it is possible to stably ensure conductivity with the fixed ring and the fixed member into which the fixed ring is fitted without providing separate components such as disc springs or wave springs. Consequently, it is possible to suppress the decrease in conductivity due to loosening of the shaft grounding member's fixing or the occurrence of vibrations, reduce the shaft voltage, which is the potential difference between the rotating member and the fixed member, prevent electrolytic corrosion of the rolling bearing, and allow electromagnetic noise to escape through the space between the rotating member and the fixed member. Furthermore, it is possible to prevent the occurrence of creep in the rolling bearing.

[0050] Furthermore, the shaft grounding member of the present invention has a soft conductive member attached to the elastic portion of a spring plate, which is in contact with the side surface of the rotating wheel or the side surface of the rotating member. The biasing force exerted by the spring plate on the soft conductive member against the side surface of the rotating wheel or the side surface of the rotating member is not very strong, so wear particles are less likely to be generated. Moreover, since the soft conductive member is made of a soft material, damage to the mating material, the rotating wheel or rotating member, is also minimized.

[0051] Furthermore, it is highly versatile as it requires no processing of the rolling bearing, has no restrictions on the type of rolling bearing, and can be applied to existing rolling bearings. In addition, the spring plate is thin, which minimizes the increase in space required for the bearing unit it is installed in.

[0052] Because the bearing unit of the present invention is equipped with the shaft grounding member of the present invention, the generation of wear particles and damage to the mating material are suppressed, and furthermore, it is highly versatile and does not increase the space required. [Brief explanation of the drawing]

[0053] [Figure 1] Figure 1(A) is a perspective view showing an example of a shaft grounding member applied to an inner ring rotating type bearing unit according to a first embodiment of the present invention, and Figure 1(B) is a front view thereof. [Figure 2] Figure 2(A) is a cross-sectional view AA of Figure 1(B), and Figure 2(B) is an enlarged cross-sectional view showing the bent portion between the annular part and the elastic part. [Figure 3] Figure 3 is an enlarged cross-sectional view corresponding to Figure 2(B), showing another example of a cut and bent piece. [Figure 4] Figure 4(A) is a cross-sectional view showing the state when the shaft grounding member shown in Figure 1 is attached to the housing, before the cut and bent piece is pressed against the outer ring side, and Figure 4(B) is a cross-sectional view showing the state when the shaft grounding member shown in Figure 1 is attached to the bearing unit. [Figure 5] Figure 5(A) is a perspective view of a shaft grounding member according to a first modified example of the first embodiment, and Figure 5(B) is a front view thereof. [Figure 6] Figure 6 is a cross-sectional view of BB in Figure 5(B). [Figure 7] Figure 7 shows the process of attaching the shaft grounding member shown in Figure 5 to the housing. Figure 7(A) is a cross-sectional view showing the state before one cut-up piece is pressed against the outer ring side. Figure 7(B) is a cross-sectional view showing the state before the other cut-up piece is pressed against the outer ring side. Figure 7(C) is a cross-sectional view showing the state in which one cut-up piece is pressed against the outer ring side via a spacer and the shaft grounding member is attached to the bearing unit. Figure 7(D) is a cross-sectional view showing the state in which the other cut-up piece is pressed against the outer ring side via a spacer and the shaft grounding member is attached to the bearing unit. [Figure 8]Figure 8(A) is a perspective view showing an example of a shaft grounding member according to a second modified example of the first embodiment of the present invention, and Figure 8(B) is a front view thereof. [Figure 9] Figure 9 is a cross-sectional view of CC in Figure 8(B). [Figure 10] Figure 10(A) is a cross-sectional view showing the state when the shaft grounding member shown in Figures 8 and 9 is attached to the housing, before the folded piece is pressed against the outer ring side, and Figure 10(B) is a cross-sectional view showing the state in which the folded piece is pressed against the outer ring side via the spacer and the shaft grounding member is attached to the bearing unit. [Figure 11] Figure 11(A) is a front view showing an example of a shaft grounding member applied to the outer ring rotating side bearing unit as a shaft grounding member according to a second embodiment of the present invention, and Figure 11(B) is a DD cross-sectional view of Figure 11(A). [Figure 12] Figure 12(A) is a cross-sectional view showing the state when the shaft grounding member shown in Figure 11 is attached to the fixing member, before the cut and bent piece is pressed against the inner ring side, and Figure 12(B) is a cross-sectional view showing the state in which the cut and bent piece is pressed against the inner ring side via the spacer and the shaft grounding member is attached to the bearing unit. [Figure 13] Figure 13 is a cross-sectional view showing an example of an inner ring rotating type bearing unit equipped with a shaft grounding member according to the third embodiment of the present invention. [Figure 14] Figure 14 is a cross-sectional view showing an example of an inner ring rotating type bearing unit equipped with another shaft grounding member according to the third embodiment of the present invention. [Figure 15] Figure 15 is a cross-sectional view showing an example of an outer ring rotating type bearing unit equipped with a shaft grounding member according to the fourth embodiment of the present invention. [Figure 16] Figure 16 is a cross-sectional view showing an example of an outer ring rotating type bearing unit equipped with another shaft grounding member according to the fourth embodiment of the present invention. [Figure 17] Figure 17 is a cross-sectional view of a modified axial grounding member according to the present invention, corresponding to (A) in Figure 2. [Figure 18]Figure 18 is a cross-sectional view showing an example of a bearing unit equipped with the shaft grounding member shown in Figure 17. [Modes for carrying out the invention]

[0054] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiments described below, and can be modified and implemented as desired without departing from the spirit of the invention.

[0055] (First embodiment: Shaft grounding member and bearing unit for inner ring rotation) In the first embodiment, a shaft grounding member and a bearing unit applied to an inner ring type bearing unit in which the rotating ring is the inner ring will be described with reference to Figures 1 to 4.

[0056] As shown in Figure 1, the shaft grounding member 1A for inner ring rotation comprises a spring plate 10A composed of an annular portion 11A and a plurality of elastic portions 13A that are bent at the inner diameter end 12A of the annular portion 11A and extend radially toward the center of the annular portion 11A. As shown in Figures 2 and 4, the elastic portions 13A are bent toward the right in the figures so that when mounted on the bearing unit 100A, they move closer to the inner ring 52 side of the rolling bearing 50. In addition, notches 15A are formed on both sides of the bent portion between the elastic portion 13A and the annular portion 11A, thereby making the elastic portion 13A more easily bent.

[0057] Furthermore, the spring plate 10A is made entirely of a thin sheet of a conductive material such as metal, and when the conductive material is metal, stainless steel is preferred for reasons such as ease of processing and less rust formation.

[0058] A soft conductive member 20 is attached to the surface of each elastic part 13A facing the inner ring 52 of the rolling bearing 50, and the spring plate 10A and the soft conductive member 20 constitute the shaft grounding member 1A. The soft conductive member 20 is attached to the elastic part 13A using adhesive.

[0059] As the flexible conductive member 20, a flexible base material into which a conductive material is mixed or supported, or commercially available products referred to as "conductive sheets" can be used. As the flexible base material, at least one selected from porous materials and resin-impregnated porous materials can be used. As the porous material, paper, cloth, nonwoven fabric, resin sheet, or a soft porous material such as sponge can be used. Of these, it is preferable to use at least one selected from soft porous materials such as nonwoven fabric, woven fabric and sponge, and resin-impregnated soft porous materials such as resin-impregnated nonwoven fabric, resin-impregnated woven fabric and sponge as the base material. When a resin-impregnated porous material is used as the base material for the flexible conductive member 20, the resin coats its skeleton, allowing the flexible conductive member 20 to be strengthened to the desired level while maintaining its flexible properties. Therefore, it is more preferable to use at least one selected from resin-impregnated nonwoven fabrics, resin-impregnated woven fabrics, and resin-impregnated soft porous materials such as sponges as the base material.

[0060] Furthermore, when using a resin-impregnated porous material as the base material, it is preferable to use a thermosetting resin as the resin to impregnate the porous material. Any thermosetting resin that can be impregnated into the base material and is thermosetting is acceptable, and examples include phenolic resin, modified phenolic resin, epoxy resin, modified epoxy resin, polyimide resin, silicone resin, polyester resin, polyurethane resin, and rubber resin.

[0061] As the conductive material to be mixed into or supported on the soft substrate, it is preferable to use at least one selected from metal fibers such as silver, copper, gold, aluminum, and stainless steel, and their pulverized or powdered forms, as well as conductive carbon fibers, and their pulverized or powdered forms.

[0062] Furthermore, as shown in Figure 2(B), the bending angle θ1 between the annular portion 11A and the elastic portion 13A is appropriately set 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 contacts the side surface 52a of the inner ring 52 of the rolling bearing 50. The bending angle θ1 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. By decreasing the bending angle θ1, the biasing force can be increased, and conversely, by increasing the bending angle θ1, the biasing force can be decreased.

[0063] There are no restrictions on the planar shape of the flexible conductive member 20; in addition to the sector shape shown in Figure 1(A), it may also be rectangular. Furthermore, it may consist of multiple small pieces.

[0064] Furthermore, the annular portion 11A has multiple notches 16A formed from the outer edge toward the inner circumference, and between adjacent notches 16A, 16A, a cut-out piece 18 (bent portion) is formed, bent from the starting point 17A. The cut-out piece 18 is bent axially so that its tip slopes toward the far side of the paper in Figure 1(B), that is, it is bent in the opposite direction to the axial direction in which the elastic portion 13A bends. The tip of the cut-out piece 18 is formed in a straight line and is located on the inner diameter side of the imaginary circle connecting multiple arc-shaped portions whose outer circumferences are not arc-shaped and on which the cut-out piece 18 is not formed.

[0065] Furthermore, the cut-out pieces 18 may be bent axially so that their tips are angled toward the front of the paper in Figure 1(B). Also, although the cut-out pieces 18 are formed at four equally spaced locations in Figure 1, there is no limit to the number. Moreover, although the multiple cut-out pieces 18 are formed alternately with multiple arc portions as shown in the figure, they are not limited to this arrangement and may be formed around the entire circumference of the annular portion 11A.

[0066] As shown in Figure 2(B), there is no restriction on the cutting angle θ2 of the cutting piece 18 relative to the annular portion 11A, and it is set appropriately according to the desired biasing force (pressing force). By reducing the cutting angle θ2, the biasing force can be weakened, and conversely, by increasing the cutting angle θ2, the biasing force can be increased.

[0067] In Figure 2(B), the cut and bent piece 18 is formed by a single bending process and has a flat surface. However, as shown in Figure 3, it may be folded multiple times (twice in the example shown) to form a stepped cross-section.

[0068] Furthermore, such a spring plate 10A can be formed by, for example, blanking, wire cutting, or laser processing to create a predetermined shape, followed by bending using a press or the like, but the manufacturing method is not limited to these.

[0069] Figure 4 shows a bearing unit 100A with the shaft grounding member 1A configured in this way. The rolling bearing 50 has a plurality of rolling elements (balls) 53 between the outer ring 51 and the inner ring 52, and the plurality of rolling elements 53 are held in place by a cage 54 so that they can roll freely, and the plurality of rolling elements 53 are lubricated with lubricating oil or grease composition. Here, the rotating ring is the inner ring 52, into which a shaft 60 directly connected to a motor (not shown) is fitted. The outer ring 51 is a stationary ring and is fixed to the housing 70. Note that the configuration of the rolling bearing 50 is not limited to this and may be configured in other ways.

[0070] As shown in Figure 4(A), when attaching the shaft grounding member 1A to the bearing unit 100A, the conductive spacer 30 is first fitted into the inner diameter side of the housing 70, and then the shaft grounding member 1A is fitted into the inner diameter side of the housing 70. After that, the conductive retaining member 80 is fitted into the inner diameter side of the housing 70 and the retaining member 80 is pressed against the outer ring 51. As a result, the annular portion 11A of the shaft grounding member 1A is pressed against the side surface of the outer ring 51 via the conductive spacer 30. Here, the cut and bent portion 18 of the shaft grounding member 1A is elastically deformed by the retaining member 80, so an axial spring reaction force acts on the spacer 30 and the retaining member 80, and as a result the pressing force against the side surface 51a of the outer ring 51 via the spacer 30 also increases.

[0071] The thickness of the spacer 30 should be determined considering the amount of pressure applied by the spring plate 10A and the thickness of the soft conductive member 20. Alternatively, the annular portion 11A of the shaft grounding member 1A may directly contact the side surface of the outer ring 51 without the spacer 30.

[0072] In an inner ring rotating type bearing unit 100A that does not incorporate a shaft grounding member 1A, current from the motor normally flows through the shaft 60 to the inner ring 52, energizing the rolling elements 53 and the outer ring 51 inside the bearing, causing electrolytic corrosion of the rolling bearing 50. In contrast, in the first embodiment, the soft conductive member 20 of the shaft grounding member 1A is mounted on the housing 70 so as to abut against the side surface 52a of the inner ring 52. Furthermore, the annular portion 11A of the spring plate 10A is electrically connected to the side surface of the outer ring 51 via a conductive spacer 30, and is also electrically connected to a conductive retaining member 80.

[0073] As a result, the current from the shaft 60 flows from the soft conductive member 20 through the inner ring 52 to the elastic portion 13A and the annular portion 11A of the spring plate 10A, and then flows to the housing 70 via the cut-and-bent piece 18 of the annular portion 11A, the outer edge of the arc portion of the annular portion 11A, the retaining member 80, the spacer 30 and the outer ring 51. Note that because the outer ring 51 has a large contact area with the housing 70, the current that flows through the outer ring 51 does not pass through the rolling elements 53 and flows to the housing 70.

[0074] In this way, the shaft grounding member 1A grounds the rotating member, the shaft 60, and the fixed member, the housing 70, so that current does not flow inside the bearing, and the shaft voltage, which is the potential difference between the rotating member and the fixed member, can be significantly reduced. Therefore, electrolytic corrosion of the rolling bearing 50 can be prevented, and electromagnetic noise can be dissipated through the space between the rotating member, the shaft 60, and the fixed member, the housing 70.

[0075] In this embodiment, the outer edge of the arc portion of the annular portion 11A and the spacer 30 are in contact with the housing 70. However, it is also possible to configure it so that it does not come into contact with the housing 70, but is instead held between the outer ring 51 and the retaining member 80. In that case, the current flowing through the annular portion 11A flows to the housing 70 via the outer ring 51 and the retaining member 80.

[0076] 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 will not be damaged, and a decrease in the rotational torque of the inner ring 52 can be suppressed. If the base material of the flexible conductive member 20 is porous, it has oil-absorbing and oil-retaining properties, so oil is easily discharged between adjacent elastic parts 13A when the shaft rotates, and it is difficult for an oil film to form, thus providing good conductivity even when used in oil. Furthermore, by making the base material of the flexible conductive member 20 porous, the coefficient of friction is suppressed even when used in environments other than oil, and the reduction in the rotational torque of the inner ring 52 can be suppressed.

[0077] Furthermore, the spring plate 10A of the shaft contact member 1A is thin, 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, making it extremely versatile.

[0078] As described above, by increasing the contact area between the soft conductive member 20 of the shaft grounding member 1A and the side surface 52a of the inner ring 52 of the rolling bearing 50, the shaft voltage between the rotating member and the stationary member can be stably reduced. Since the spring plate 10A is an elastic member made of a thin plate that is bent as a whole, when the annular portion 11A of the shaft grounding member 1A is pressed against the outer ring 51, the elastic force due to the pressing acts on the elastic portion 13A, causing it to be pushed open so that the bending angle θ1 shown in Figure 2(B) becomes larger, and the entire elastic portion 13A moves towards the rolling bearing 50. Accordingly, the portion of the soft conductive member 20 that was separated from the side surface 52a of the inner ring 52 in Figure 4(A) also moves towards 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. This improves conductivity between the soft conductive member 20 and the inner ring 52, more effectively preventing electrolytic corrosion of the rolling bearing 50 and reducing electromagnetic noise.

[0079] Furthermore, the cut-out piece 18 increases the pressing force of the shaft grounding member 1A against the side surface of the outer ring 51. As a result, even if axial play occurs between the outer ring 51 and the housing 70, the shaft grounding member 1A remains fixed, and electrical contact between the annular portion 11A and the side surface of the outer ring 51 via the conductive spacer 30, as well as electrical contact with the conductive retaining member 80, is maintained. Therefore, the aforementioned shaft voltage can be reduced more stably, thereby preventing electrolytic corrosion and reducing electromagnetic noise.

[0080] Furthermore, this cut-out piece 18 increases the pressing force on the side of the outer ring 51 of the shaft contact member 1A. As a result, even if the fit between the outer ring 51 and the housing 70 becomes loose, the outer ring 51 can be fixed to the housing 70, thereby suppressing creep of the rolling bearing 50.

[0081] In particular, in a bearing unit 100A where the housing 70 is made of aluminum and the housing 70 and outer ring 51 are made of different materials, the dimensional change due to the difference in thermal expansion coefficients between the housing 70 and the outer ring 51 is large, making creep and loosening of the fit more likely to occur. Therefore, an increase in the pressing force at the mounting portion of the shaft contact member 1A by the cut and bent piece 18 becomes more significant.

[0082] Furthermore, while disc springs and wave springs are commonly used in rolling bearing units to suppress creep and axial play, the inclusion of a cut-and-bent piece 18 in the shaft contact member 1A eliminates the need for disc springs and wave springs, thereby reducing the cost of the rolling bearing unit.

[0083] (First embodiment, first modified example) In the axial grounding member 1A of the above embodiment, all cut-up pieces 18 are bent to one side in the axial direction. However, as shown in Figures 5 and 6, one cut-up piece 18A bent to one side in the axial direction and the other cut-up piece 18B bent to the other side in the axial direction may be formed alternately.

[0084] In this case as well, as shown in Figure 7, when the annular portion 11A of the shaft grounding member 1A is pressed against the side surface of the outer ring 51 via the conductive spacer 30 by the conductive pressing member 80, the cut and bent pieces 18A and 18B of the shaft grounding member 1A are elastically deformed by the pressing member 80, and an axial spring reaction force acts on the spacer 30 and the pressing member 80. As a result, the pressing force against the side surface 51a of the outer ring 51 via the spacer 30 is also increased, the fixing of the shaft grounding member 1A is maintained more reliably, and the same effects as in the above embodiment can be achieved. Furthermore, the cut-up pieces 18A and 18B are not limited to being formed alternately; either cut-up piece 18A or 18B may be formed at any position.

[0085] (Second modified example of the first embodiment) Furthermore, as shown in Figures 8 and 9, the axial grounding member 1A may have multiple folded pieces 22 (bent portions) instead of the multiple cut-up pieces 18 which are the biasing portions in the above embodiment.

[0086] Multiple notches 16A are formed in the annular portion 11A, extending from the outer edge toward the inner circumference, and folded pieces 22 are formed between adjacent notches 16A, 16A, folded back from the starting point 17A. The tip of the folded piece 22 is folded back toward the far side of the paper in Figure 8(B), that is, it is folded back in the opposite direction to the axial direction in which the elastic portion 13A bends. The starting point 17A of the folded piece 22 is located on the inner diameter side of the imaginary circle connecting multiple arc-shaped portions whose outer circumferences are not arc-shaped and for which the folded piece 22 is not formed.

[0087] The folded-over piece 22 may also be formed by folding its tip towards the front of the paper in Figure 8(B). Furthermore, although the folded-over piece 22 is formed at four equally spaced locations in Figure 8, there is no limit to the number of pieces. Additionally, while the multiple folded-over pieces 22 are formed alternately with multiple arc portions as shown in the figure, they are not limited to this arrangement and may be formed around the entire circumference of the annular portion 11A.

[0088] As shown in Figure 9, there is no restriction on the bending angle θ3 of the folded piece 22 relative to the annular portion 11A, and it can be set appropriately according to the desired biasing force (pressing force). By reducing the bending angle θ3, the biasing force can be weakened, and by increasing the bending angle θ3, the biasing force can be increased.

[0089] In this case as well, as shown in Figure 10, when the annular portion 11A of the shaft grounding member 1A is pressed against the side surface of the outer ring 51 via the conductive spacer 30 by the conductive pressing member 80, the folded portion 22 of the shaft grounding member 1A is elastically deformed by the pressing member 80, so that an axial spring reaction force acts on the spacer 30 and the pressing member 80. As a result, the pressing force against the side surface 51a of the outer ring 51 via the spacer 30 is also increased, the fixing of the shaft grounding member 1A is maintained more securely, and the same effects as in the above embodiment can be achieved.

[0090] In the second modified example, the folded portion 22 is formed by folding back the portion between adjacent notches 16A, 16A in the axial direction, but it may also be formed by folding back the portion extending radially from the outer edge of the annular portion 11A in the axial direction.

[0091] Furthermore, in the folded portion of the second modified example, similar to the cut-out portion of the first modified example, the portion between the pair of notches 16A, 16A cut out from the outer peripheral edge of the annular portion 11A, or the portion extending radially from the outer peripheral edge of the annular portion 11A, may be configured to have one folded portion folded back to one side in the axial direction and the other folded portion folded back to the other side in the axial direction.

[0092] (Second embodiment: Shaft grounding member and bearing unit for outer ring rotation) In the second embodiment, a shaft grounding member and a bearing unit applied to an outer ring rotating type bearing unit in which the rotating ring is the outer ring will be described with reference to Figures 11 and 12.

[0093] As shown in Figure 11, the shaft grounding member 1B for outer ring rotation comprises a spring plate 10B composed of an annular portion 11B and a plurality of elastic portions 13B that are bent at the outer diameter end 12B of the annular portion 11B and extend radially from the center of the annular portion 11B toward the outer circumference. As shown in Figure 12, the elastic portions 13B are bent toward the right in the figure so that they 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 portion 13B toward the annular portion 11B.

[0094] A soft conductive member 20 is attached to the surface of each elastic part 13B facing the outer ring 51 of the rolling bearing 50, and the spring plate 10B and the soft conductive member 20 constitute the shaft grounding member 1B. The soft conductive member 20 is the same as the shaft grounding member 1A described above, and its explanation is omitted.

[0095] Furthermore, the annular portion 11B has multiple notches 16B formed from the inner periphery toward the outer periphery, and between adjacent notches 16B, 16B, a bent cut-out piece 18 (bent portion) is formed from the starting point 17B. The cut-out piece 18 is bent axially so that its tip slopes toward the back of the paper in Figure 11(A), similar to the first embodiment, but it may also be bent axially so that its tip slopes toward the front of the paper. The starting point 17B of the cut-out piece 18 is located on the outer diameter side of a virtual circle that connects multiple arc-shaped inner circumferences where the cut-out piece 18 is not formed.

[0096] Furthermore, although the cut-out pieces 18 are formed at four equally spaced locations, there is no limit to the number of pieces. In addition, although the multiple cut-out pieces 18 are formed alternately with the multiple arc portions, they are not limited to this arrangement and may be formed around the entire circumference of the annular portion 11B.

[0097] Although not shown in the illustration, the cut-out pieces 18 can also be formed on the front and back sides of the annular portion 11B, as shown in Figure 5. In this case, the cut-out pieces folded on the front side and the cut-out pieces folded on the back side may be arranged alternately as shown in Figure 5, or in any arrangement.

[0098] As shown in Figure 12(A), in the bearing unit 100B, the inner ring 52 of the rolling bearing 50 is fixed to the fixing member 75, and the rotating member 65 is mounted on the outer ring 51. When attaching the shaft grounding member 1B to the bearing unit 100B, first the conductive spacer 30 is fitted into the inner diameter side of the fixing member 75. Then, the shaft grounding member 1B and the conductive retaining member 80 are fitted into the inner diameter side of the fixing member 75 in this order, and the cut and bent piece 18 of the shaft grounding member 1B is pressed towards the inner ring 52 by the retaining member 80. As a result, as shown in Figure 12(B), the shaft grounding member 1B is attached to the fixing member 75 such that the soft conductive member 20 abuts against the side surface 51a of the outer ring 51.

[0099] In this second embodiment, when the shaft grounding member 1B is pressed, the cut and bent piece 18 undergoes elastic deformation, and an axial spring reaction force acts on the spacer 30 and the pressing member 80. As a result, the pressing force against the side surface 52a of the inner ring 52 via the spacer 30 increases, and the shaft grounding member 1B is securely fixed in the predetermined area. The annular portion 11B of the spring plate 10B is electrically connected to the side surface of the inner ring 52 via the conductive spacer 30, and is also electrically connected to the fixing member 75 via the conductive pressing member 80.

[0100] In the second embodiment, current from a motor (not shown) that drives the rotating member 65 flows to the outer ring 51. Through the outer ring 51, the current flows from the soft conductive member 20 to the elastic portion 13B and the annular portion 11B of the spring plate 10B, and then flows to the fixed member 75 via the cut-and-bent piece 18 of the annular portion 11B, the inner circumference of the arc portion of the annular portion 11B, the retaining member 80, the spacer 30, and the inner ring 52. Since the inner ring 52 has a large contact area with the fixed member 75, the current that flows through the inner ring 52 does not pass through the rolling elements 53, but flows to the fixed member 75. In this way, the shaft grounding member 1B grounds the rotating member 65 and the fixed member 75, so that the inside of the bearing is not energized, and the shaft voltage, which is the potential difference between the rotating member 65 and the fixed member 75, can be significantly reduced. Therefore, electrolytic corrosion of the rolling bearing 50 can be prevented, and electromagnetic noise can be dissipated through the space between the rotating member 65 and the fixed member 75.

[0101] Furthermore, as shown in Figure 12(B), the retaining member 80 presses the annular portion 11B of the shaft grounding member 1B against the inner ring 52, increasing the contact area between the soft conductive member 20 and the side surface 51a of the outer ring 51. This further improves the effect of preventing electrolytic corrosion of the rolling bearing 50 and the effect of dissipating electromagnetic noise.

[0102] Furthermore, in this embodiment as well, the cut-out piece 18 increases the pressing force of the shaft grounding member 1B against the side surface 52a of the inner ring 52. Therefore, similar to the first embodiment, even if axial play occurs between the inner ring 52 and the fixing member 75, or if the fit becomes loose, stable conductivity between the inner ring 52 and the fixing member 75 can be ensured, and creep of the rolling bearing can be prevented.

[0103] In this embodiment as well, the annular portion 11B of the shaft grounding member 1B may directly contact the side surface of the inner ring 52 without providing the spacer 30. Furthermore, the inner periphery of the arc portion of the annular portion 11B and the spacer 30 may contact the fixing member 75, or they may not contact the fixing member 75 but be held between the inner ring 52 by the retaining member 80.

[0104] Furthermore, in this embodiment, instead of the cut-up piece 18, the spring plate may have both a cut-up piece that is bent to one side in the axial direction and a other cut-up piece that is bent to the other side in the axial direction, as described in the first modification of the first embodiment, or it may have a folded-back piece, as described in the second modification of the first embodiment.

[0105] (Third embodiment: Shaft grounding member and bearing unit for inner ring rotation) Figure 13 shows a case, similar to the first embodiment, where the shaft grounding member is mounted on a bearing unit in which the rotating ring is the inner ring. In this case, the shaft 60, which is the rotating member into which the inner ring 52 is fitted, has a stepped surface 60c formed thereon that is smaller in diameter than the fitting surface 60b into which the inner ring 52 is fitted.

[0106] The soft conductive member 20 of the spring plate 10A is attached to the elastic portion 13A by elastically deforming the elastic portion 13A on the surface facing the shaft 60 in the axial direction, specifically on the side surface 60a between the fitting surface 60b into which the inner ring 52 is fitted and the stepped surface 60c. Therefore, the soft conductive member 20 can come into contact with the side surface 60a of the shaft 60.

[0107] In this type of inner ring rotating bearing unit 100A, the soft conductive member 20 of the shaft grounding member 1A is mounted on the housing 70 so as to abut against the side surface 60a of the shaft 60. Furthermore, the annular portion 11A of the spring plate 10A is electrically connected to the side surface of the outer ring 51 via a conductive spacer 30, and is also electrically connected to the end face of the flange portion 71 of the housing 70.

[0108] 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 the annular portion 11A of the spring plate 10A, and then flows to the housing 70, or directly to the housing 70, via the cut-and-bent piece 18 of the annular portion 11A, the outer edge of the arc portion of the annular portion 11A, the spacer 30 and the outer ring 51. Since the outer ring 51 has a large contact area with the housing 70, the current that flows through the outer ring 51 does not pass through the rolling elements 53 and flows to the housing 70. In this way, the shaft grounding member 1A grounds the rotating member shaft 60 and the fixed member housing 70, so that the inside of the bearing is not energized, and the shaft voltage, which is the potential difference between the rotating member and the fixed member, can be significantly reduced. Therefore, electrolytic corrosion of the rolling bearing 50 can be prevented, and electromagnetic noise can be dissipated through the space between the rotating member shaft 60 and the fixed member housing 70.

[0109] Unlike the first embodiment, this embodiment does not involve contact between the shaft grounding member 1A and the side surface 52a of the inner ring 52, thereby improving the design flexibility of the rolling bearing, such as the installation of snap rings or retaining rings. Furthermore, because the shaft grounding member 1A and the rolling bearing 50 are located separately in this embodiment, it is possible to control their respective lubrication environments independently. For example, the shaft grounding member 1A can be kept in a dry environment, or the amount of lubricating oil can be increased or decreased for both the shaft grounding member 1A and the rolling bearing 50.

[0110] In particular, in the bearing unit 100A shown in Figure 13, the position where the soft conductive member 20 contacts the side surface 60a of the shaft 60 is smaller in diameter than the position where it contacts the side surface 52a of the inner ring 52, as shown in Figure 4. This allows the peripheral speed of the side surface 60a of the shaft 60 to be reduced, further suppressing the generation of wear particles and drag losses.

[0111] As shown in Figure 14, in this embodiment, the shaft 60 may be provided with a flange portion 62 that protrudes outward from the fitting surface 60b, and the soft conductive member 20 may be in contact with the side surface 60a of this flange portion 62.

[0112] Furthermore, in this embodiment as well, by having the configuration of the bent portion including the cut-up piece 18 and the folded-back piece 22 as described in the first embodiment, stable conductivity with the outer ring 51 and the housing 70 can be ensured, and creep of the rolling bearing can be prevented.

[0113] (Fourth embodiment: Shaft grounding member and bearing unit for outer ring rotation) Figure 15 shows a case, similar to the second embodiment, where the shaft grounding member is mounted on a bearing unit in which the rotating ring is the outer ring. In this case, the rotating member 65 into which the outer ring 51 is fitted has a stepped surface 65c formed thereon that is larger in diameter than the fitting surface 65b into which the outer ring 51 is fitted.

[0114] The soft conductive member 20 of the spring plate 10B is attached to the elastic portion 13B by elastically deforming the elastic portion 13B on the surface facing the rotating member 65 in the axial direction, specifically on the side surface 65a between the fitting surface 65b into which the outer ring 51 is fitted and the stepped surface 65c. Therefore, the soft conductive member 20 can come into contact with the side surface 65a of the rotating member 65.

[0115] In this type of outer ring rotating bearing unit 100B, the soft conductive member 20 of the shaft grounding member 1B is mounted on the rotating member 65 such that it abuts against the side surface 65a of the rotating member 65. Furthermore, the annular portion 11B of the spring plate 10B is electrically connected to the side surface of the inner ring 52 via a conductive spacer 30, and is also electrically connected to the end face of the flange portion 76 of the fixed member 75.

[0116] As a result, the 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 the annular portion 11B of the spring plate 10B, and then flows to the fixed member 75 via the cut-and-bent piece 18 of the annular portion 11B, the inner circumference of the arc portion of the annular portion 11B, the spacer 30 and the inner ring 52, or directly to the flange portion 76 of the fixed member 75. Note that because the inner ring 52 has a large contact area with the fixed member 75, the current that flows through the inner ring 52 does not pass through the rolling elements 53 and flows to the fixed member 75. In this way, the shaft grounding member 1B grounds the rotating member 65 and the fixed member 75, so that the inside of the bearing is not energized, and the shaft voltage, which is the potential difference between the rotating member 65 and the fixed member 75, can be significantly reduced. Therefore, electrolytic corrosion of the rolling bearing 50 can be prevented, and electromagnetic noise can be dissipated through the space between the rotating member 65 and the fixed member 75.

[0117] Unlike the second embodiment, this embodiment does not involve contact between the shaft grounding member 1B and the side surface 51a of the outer ring 51, thereby improving the design flexibility of the rolling bearing, such as the installation of snap rings or retaining rings. Furthermore, because the shaft grounding member and the rolling bearing are located separately in this embodiment, it becomes possible to control their respective lubrication environments independently. For example, the shaft grounding member can be kept in a dry environment, or the amount of lubricating oil can be increased or decreased for the shaft grounding member and the rolling bearing.

[0118] As shown in Figure 16, in this embodiment, the rotating member 65 may be provided with a flange portion 67 that protrudes inward from the fitting surface 65b, and the soft conductive member 20 may come into contact with the side surface 65a of this flange portion 67.

[0119] In particular, in the bearing unit 100B shown in Figure 16, the position where the soft conductive member 20 contacts the side surface 65a of the rotating member 65 is smaller in diameter than the position where it contacts the side surface 51a of the outer ring 51, as shown in Figure 10. This allows the peripheral speed of the side surface 65a of the rotating member 65 to be reduced, further suppressing the generation of wear particles and drag losses.

[0120] Furthermore, in this embodiment as well, by having the configuration of the bent portion including the cut-up piece 18 and the folded-back piece 22 as described in the first embodiment, stable conductivity with the inner ring 52 and the fixing member 75 can be ensured, and creep of the rolling bearing can be prevented.

[0121] It should be noted that the present invention is not limited to the embodiments described above, and can be modified and improved as appropriate. For example, in the above embodiment, the multiple elastic portions 13A and 13B of the spring plates 10A and 10B are bent toward the rotating ring, but they may also be formed flush with the annular portions 11A and 11B without being bent at the inner diameter end 12A and outer diameter end 12B. As shown in Figure 17, for example, in the case of the shaft grounding member 1A for inner ring rotation, the annular portion 11A and the elastic portion 13A are linearly continuous in cross-sectional view.

[0122] Therefore, in the bearing unit 100A shown in Figure 18, when the annular portion 11A of the shaft grounding 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 shaft grounding member 1A elastically deforms by 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 come into contact with the side surface of the inner ring 52. This allows the same function as in the above embodiment to be achieved.

[0123] In this case, bending of the spring plate 10A is unnecessary, so the shaft grounding member 1A can be manufactured at a low cost, and the spring plate 10A and the soft conductive member 20 can be easily bonded together.

[0124] Furthermore, in this embodiment, the spring plate is configured to have multiple elastic parts extending radially toward the center of the annular portion, but it may also be configured to have a single elastic part extending toward the center of the annular portion.

[0125] Furthermore, the axial grounding member of the present invention can also be suitably used when only one of the following is required: prevention of electrolytic corrosion and suppression of electromagnetic noise generation.

[0126] Furthermore, when the primary objective is to prevent galvanic corrosion, the term "shaft grounding member" in this specification may be replaced with "galvanic corrosion prevention member," and the term "rolling bearing unit" may be replaced with "galvanic corrosion prevention rolling bearing unit." Specifically, this is as follows.

[0127] (1) A rolling bearing unit having a rolling bearing in which one raceway is a fixed ring and the other raceway is a rotating ring, wherein an anti-corrosion member is attached to the rolling bearing unit to prevent galvanic corrosion of the rolling bearing, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating wheel, In addition to being equipped, The aforementioned flexible conductive member is capable of contacting the side surface of the rotating wheel. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A corrosion-preventing member for rolling bearings characterized by the following.

[0128] (2) Each of the bent portions is a cut-out piece formed by folding in the axial direction between a pair of notches cut out from the periphery of the annular portion. (1) The anti-corrosion member for rolling bearings described in (1).

[0129] (3) The plurality of bent portions have a portion between a pair of notches cut out from the periphery of the annular portion that is bent in one direction in the axial direction and a portion that is bent in the other direction in the axial direction. (1) The anti-corrosion member for rolling bearings described in (1).

[0130] (4) Each of the bent portions is a portion between a pair of notches cut out from the periphery of the annular portion, or a folded piece formed by folding back in the axial direction a portion extending radially from the periphery of the annular portion. (1) The anti-corrosion member for rolling bearings described in (1).

[0131] (5) The plurality of bent portions have a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion, which has one folded piece folded back to one side in the axial direction and the other folded piece folded back to the other side in the axial direction. (1) The anti-corrosion member for rolling bearings described in (1).

[0132] (6) The annular portion is pressed against the side surface of the fixed ring with a spacer in between. A corrosion-preventing member for rolling bearings as described in any one of (1) to (5).

[0133] (7) The soft conductive member is a resin-impregnated nonwoven fabric, a nonwoven fabric, a resin-impregnated woven fabric, a woven fabric, It consists of at least one selected from a resin-impregnated soft porous material and a soft porous material. A corrosion-preventing member for rolling bearings as described in any one of (1) to (6).

[0134] (8) The plurality of elastic parts of the spring plate are bent toward the rotating wheel, A corrosion-preventing member for rolling bearings as described in any one of (1) to (7).

[0135] (9) The plurality of elastic parts of the spring plate are formed flush with the annular part, A corrosion-preventing member for rolling bearings as described in any one of (1) to (7).

[0136] (10) A rolling bearing unit having a rolling bearing in which one raceway is a fixed ring and the other raceway is a rotating ring, wherein an anti-corrosion member is attached to the rolling bearing unit to prevent galvanic corrosion of the rolling bearing, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating member into which the rotating ring is fitted, In addition to being equipped, The soft conductive member is capable of contacting the side surface of the rotating member. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A corrosion-preventing member for rolling bearings characterized by the following.

[0137] (11) Each of the bent portions is a cut-out piece in which the portion between a pair of notches cut out from the periphery of the annular portion is bent in the axial direction. (10) The anti-corrosion member for rolling bearings described in (10).

[0138] (12) The plurality of bent portions each have a cut-out piece in which the portion between a pair of notches cut out from the periphery of the annular portion is bent in one axial direction, and a cut-out piece in which the portion is bent in the other axial direction. (10) The anti-corrosion member for rolling bearings described in (10).

[0139] (13) Each of the bent portions is a portion between a pair of notches cut out from the periphery of the annular portion, or a folded piece formed by folding back in the axial direction a portion extending radially from the periphery of the annular portion. (10) The anti-corrosion member for rolling bearings described in (10).

[0140] (14) The plurality of bent portions each have a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion, which is folded back to one side in the axial direction and the other folded back to the other side in the axial direction. (10) The anti-corrosion member for rolling bearings described in (10).

[0141] (15) The annular portion is pressed against the side surface of the fixed ring with a spacer in between. A corrosion-preventing member for rolling bearings as described in any one of (10) to (14).

[0142] (16) The flexible 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 flexible porous body, and a flexible porous body. A corrosion-preventing component for rolling bearings as described in any one of (10) to (15).

[0143] (17) The plurality of elastic parts of the spring plate are bent toward the rotating wheel, A corrosion-preventing member for rolling bearings as described in any one of (10) to (16).

[0144] (18) The plurality of elastic portions of the spring plate are formed flush with the annular portion, A corrosion-preventing member for rolling bearings as described in any one of (10) to (16).

[0145] (19) A rolling bearing is provided in which one raceway is a fixed ring and the other raceway is a rotating ring, A rolling bearing unit that prevents electrolytic corrosion, characterized by being fitted with an electrolytic corrosion prevention member for rolling bearings described in any one of (1) to (18).

[0146] Furthermore, when the primary objective is to suppress the generation of electromagnetic noise, the term "shaft grounding member" in this specification may be replaced with "electromagnetic noise suppression member," and the term "rolling bearing unit" may be replaced with "electromagnetic noise suppression rolling bearing unit." [Explanation of symbols]

[0147] 1A, 1B Axle grounding member 10A, 10B Spring Plate 11A, 11B Annular section 12A Inner diameter end 12B Outer diameter end 13A, 13B Elastic part 15A, 15B Notches 17A,17B starting point 18 Cut and bent piece (bent section) 20 Flexible conductive material 22 Folded-over piece (bent section) 30 Spacers 50 bearings 51 Outer ring 51a,52a side 52 Inner Ring 53 Rolling element 54 Cage 60 shaft 65 Rotating member 70 Housing 75 Fixing member 80 Retaining member 100A, 100B Bearing Unit

Claims

1. A shaft grounding member that is mounted on a rolling bearing unit having a rolling bearing in which one raceway is a fixed wheel and the other raceway is a rotating wheel, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating wheel, In addition to being equipped, The aforementioned flexible conductive member is capable of contacting the side surface of the rotating wheel. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A shaft grounding member for rolling bearings characterized by the following.

2. Each of the aforementioned bent portions is a cut-out piece formed by folding in the axial direction between a pair of notches cut out from the periphery of the annular portion. The shaft grounding member for a rolling bearing according to claim 1.

3. Each of the aforementioned bent portions has one cut-out piece that is bent in one axial direction and the portion between a pair of notches cut out from the periphery of the annular portion, and the other cut-out piece that is bent in the other axial direction. The shaft grounding member for a rolling bearing according to claim 1.

4. Each of the aforementioned bent portions is a folded piece formed by folding back in the axial direction a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion. The shaft grounding member for a rolling bearing according to claim 1.

5. Each of the aforementioned bent portions has a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion, which is folded back to one side in the axial direction and has a second folded back portion which is folded back to the other side in the axial direction. The shaft grounding member for a rolling bearing according to claim 1.

6. The annular portion is pressed against the side surface of the fixed ring with a spacer in between. The shaft grounding member for a rolling bearing according to claim 1.

7. The flexible 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 flexible porous body, and a flexible porous body. The shaft grounding member for a rolling bearing according to claim 1.

8. The plurality of elastic parts of the spring plate are bent toward the rotating wheel. The shaft grounding member for a rolling bearing according to claim 1.

9. The plurality of elastic portions of the spring plate are formed flush with the annular portion. The shaft grounding member for a rolling bearing according to claim 1.

10. A shaft grounding member that is mounted on a rolling bearing unit having a rolling bearing in which one raceway is a fixed wheel and the other raceway is a rotating wheel, A spring plate made of a thin sheet of conductive material is composed of a ring-shaped portion and a plurality of elastic portions extending radially from the ring-shaped portion, A soft conductive member is mounted on the surface of the elastic portion facing the rotating member into which the rotating ring is fitted, In addition to being equipped, The soft conductive member is capable of contacting the side surface of the rotating member. The spring plate is provided with a plurality of bent portions that are bent in the axial direction on the annular portion facing the side surface of the fixed ring, and which apply a pressing force to the fixed ring by deforming themselves. A shaft grounding member for rolling bearings characterized by the following.

11. Each of the aforementioned bent portions is a cut-out piece formed by folding in the axial direction between a pair of notches cut out from the periphery of the annular portion. The shaft grounding member for rolling bearings according to claim 10.

12. Each of the aforementioned bent portions has one cut-out piece that is bent in one axial direction and the portion between a pair of notches cut out from the periphery of the annular portion, and the other cut-out piece that is bent in the other axial direction. The shaft grounding member for rolling bearings according to claim 10.

13. Each of the aforementioned bent portions is a folded piece formed by folding back in the axial direction a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion. The shaft grounding member for rolling bearings according to claim 10.

14. Each of the aforementioned bent portions has a portion between a pair of notches cut out from the periphery of the annular portion, or a portion extending radially from the periphery of the annular portion, which is folded back to one side in the axial direction and has a second folded back portion which is folded back to the other side in the axial direction. The shaft grounding member for rolling bearings according to claim 10.

15. The annular portion is pressed against the side surface of the fixed ring with a spacer in between. The shaft grounding member for rolling bearings according to claim 10.

16. The flexible 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 flexible porous body, and a flexible porous body. The shaft grounding member for rolling bearings according to claim 10.

17. The plurality of elastic parts of the spring plate are bent toward the rotating wheel. The shaft grounding member for rolling bearings according to claim 10.

18. The plurality of elastic portions of the spring plate are formed flush with the annular portion. The shaft grounding member for rolling bearings according to claim 10.

19. It is equipped with a rolling bearing in which one raceway is a fixed ring and the other raceway is a rotating ring, A rolling bearing unit characterized by being fitted with a rolling bearing shaft grounding member according to any one of claims 1 to 18.

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