Electric corrosion prevention member for rolling bearing and electric corrosion prevention rolling bearing unit

Abstract

The present disclosure provides an electrolytic corrosion prevention member and an electrolytic corrosion prevention rolling bearing unit to which the electrolytic corrosion prevention member is attached, the electrolytic corrosion prevention member being capable of suppressing the generation of abrasion powder from a conductive member or the generation of abrasion powder accompanying sliding contact between the conductive member and a counterpart member, and also being capable of suppressing damage to the counterpart member, and not only further being capable of preventing damage to the counterpart member. The electric corrosion prevention member does not form new processing on a bearing, and can cope with an existing bearing in a manner that the type of the bearing is not limited. This electrolytic corrosion prevention member for a rolling bearing is provided with: a spring plate comprising a circular ring part and an elastic part that is continuous from the inner peripheral end of the circular ring part and extends toward the center of the circular ring part, said spring plate being formed from a thin plate of an electrically conductive material; and a soft conductive member which is attached to a surface of the elastic portion on the side facing the rolling bearing, and which can be brought into contact with an end surface of a shaft fitted into the rolling bearing. In addition, the electric corrosion prevention rolling bearing unit is provided with the electric corrosion prevention member.

Description

Technical Field

[0001] The present invention relates to an anti-electrocorrosion member for a rolling bearing which is attached to prevent electrocorrosion of a rolling bearing in a rolling bearing unit, and an anti-electrocorrosion rolling bearing unit to which the anti-electrocorrosion member for a rolling bearing is attached. Background Art

[0002] In recent years, the practical application of electric vehicles that drive the wheels by configuring an electric motor as a drive source on the inner side or near the wheel has gradually advanced. Such a drive motor is generally called an in-wheel motor. Regarding the structure of a general in-wheel motor, a stator is fixed to the motor housing, and a rotor is configured on the inner diameter side of the stator in a manner that a gap is opened in the radial direction. This is a so-called inner rotor type motor. In addition, as a driving method for the in-wheel motor, considering the performance and control performance of the motor, a brushless DC (Direct Current) motor driven by an inverter is more commonly used.

[0003] In the drive method using an inverter, a potential difference is generated between the stator and the rotor due to the parasitic capacitance between the stator and the rotor. Due to this potential difference, the so-called shaft voltage / shaft current is generated. When this shaft current passes through the rolling bearing supporting the rotor, a phenomenon called "electrocorrosion" occurs, which damages the rolling bearing. Specifically, current flows locally in the contact area between the raceway surface of the outer ring / inner ring of the rolling bearing and the rolling element, and the track surface or rolling surface melts, etc., resulting in unevenness. As a result, the raceway surface and rolling element surface of the bearing become rough, which not only causes noise and vibration, but also affects the life of the bearing when excessive electrocorrosion occurs.

[0004] In order to prevent electrical corrosion of rolling bearings, measures have been taken to sandwich conductive components. For example, the following technology is proposed in Patent Documents 1 and 2, which is composed of a contact body for electrically conducting with the rotor of the motor, an elastic body for pressing the contact body toward the rotor side, and a storage portion for accommodating the contact body and the elastic body. This technology arranges the storage portion in the motor housing so that it is electrically connected to the motor stator via the motor housing.

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

[0006] Moreover, Patent Document 4 proposes an anti-electrocorrosion device, which uses an elastic conductor, which bends an annular seat portion connected to the end face of the bearing outer ring into a wave washer shape, and has a contact piece that extends from the inner side of the annular seat portion and connects to the vicinity of the center portion of the end face of the rotating shaft. When the annular seat portion is overlapped with the end face of the bearing outer ring embedded in the bearing seat and the contact piece is in contact with the vicinity of the center portion of the end face of the rotating shaft embedded in the bearing inner ring, the surface of the annular seat portion is pressed by the cover-like wall of the bearing seat, so that the anti-electrocorrosion device is electrically conductive.

[0007] In addition, Patent Document 5 proposes the following technology: a rod-shaped conductive brush is accommodated in a support hole provided in one of the two rings, and an elastic component is used to apply force to the top end of the conductive brush toward the other ring side so that the top end of the conductive brush is in sliding contact, thereby achieving electrical conduction between the two rings.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2011-135720

[0011] Patent Document 2: Japanese Patent Application Publication No. 2011-135722

[0012] Patent Document 3: Japanese Patent Application Publication No. 2020-127257

[0013] Patent Document 4: Japanese Patent Application Laid-Open No. 2002-146568

[0014] Patent Document 5: Japanese Utility Model Application Laid-Open No. 4-8820

[0015] However, in any technology described in any patent document, the wear powder generated from the conductive member will become a contaminant of the lubricating oil or grease composition sealed therein for lubrication, and may damage the raceway surface or rolling surface. In addition, the wear powder may also damage the counterpart member of the conductive member.

[0016] Specifically, in Patent Documents 1 and 2, the contact body, elastic body, and storage body are metal components, which will slide in contact with the vibration of the motor, thereby generating metal powder. In addition, the contact body, elastic body, and storage body need to be arranged in the motor housing, and space for this operation is also required.

[0017] In addition, in Patent Document 3, the tip of the broom-shaped conductive fiber is brought into contact with the outer peripheral surface of the rotating shaft, but in order to make the contact area between the tip of the broom-shaped conductive fiber and the rotating shaft larger than when the two are simply brought into contact, the broom-shaped conductive fiber is brought into contact with the outer peripheral surface of the rotating shaft in a bent state. That is, the tip of the broom-shaped conductive fiber is brought into contact with the outer peripheral surface of the rotating shaft with a certain degree of large pressing force, so the wear powder is generated. At the same time, the outer peripheral surface of the rotating shaft, which is the counterpart of the broom-shaped conductive fiber, is also damaged.

[0018] Furthermore, in Patent Document 4, since both the elastic conductor and the rotating shaft are made of metal and the two are in sliding contact, metal powder is generated and the end surface of the rotating shaft, which is the counterpart member of the elastic conductor, is damaged.

[0019] In addition, in Patent Document 5, the tip of the rod-shaped conductive brush contacts the other ferrule under a force applied thereto, so that abrasion powder of the conductive brush is generated. At the same time, the other ferrule, which is the counterpart member of the conductive brush, is also damaged. Furthermore, a support hole for accommodating the conductive brush and the elastic member needs to be formed in the ferrule, which applies a large load to the ferrule. Summary of the invention

[0020] Therefore, the object of the present invention is to provide an anti-electrocorrosion component and an anti-electrocorrosion rolling bearing unit equipped with the anti-electrocorrosion component, wherein the anti-electrocorrosion component is a space-saving and inexpensive structure, can suppress the generation of wear powder from the conductive component or the generation of wear powder accompanying the sliding contact between the conductive component and the other component, and can also suppress damage to the other component. Not only that, the anti-electrocorrosion component will not form new processing on the bearing. In addition, it can cope with existing bearings in a manner without restriction on the type of bearing.

[0021] The above-mentioned object of the present invention is achieved by the following structure [1] of the anti-electrolytic corrosion member for rolling bearings.

[0022] [1] An anti-electrolytic corrosion component for a rolling bearing, which is attached to a rolling bearing unit having an inner ring rotating type rolling bearing so as to prevent electrolytic corrosion of the rolling bearing in the rolling bearing unit, wherein the outer ring of the rolling bearing is fixed to a seat body, and a shaft directly connected to a motor is embedded in the inner ring of the rolling bearing, wherein the anti-electrolytic corrosion component for a rolling bearing is characterized in that it has:

[0023] a spring plate comprising a circular ring portion and an elastic portion, wherein the spring plate is formed of a thin plate of a conductive material, wherein the elastic portion is continuous from an inner peripheral side end portion of the circular ring portion and extends toward a center of the circular ring portion; and

[0024] a soft conductive member attached to the surface of the elastic portion on the side opposite to the rolling bearing,

[0025] Furthermore, the soft conductive member can abut against the end surface of the shaft.

[0026] Furthermore, preferred embodiments of the present invention of the electrolytic corrosion preventing member for rolling bearings relate to the following [2] to [6].

[0027] [2] The anti-electrolytic corrosion member for a rolling bearing according to [1], wherein the annular portion is pressed against the side surface of the outer ring in a manner interposing a spacer.

[0028] [3] The anti-electrolytic corrosion component for a rolling bearing according to [1] is characterized in that the soft conductive component is composed of at least one selected from a resin impregnation of a non-woven fabric, a non-woven fabric, a resin impregnation of a woven fabric, a woven fabric, a resin impregnation of a soft porous body, and a soft porous body.

[0029] [4] The anti-corrosion component for a rolling bearing according to [2] is characterized in that the soft conductive component is composed of at least one selected from a resin impregnation of a non-woven fabric, a non-woven fabric, a resin impregnation of a woven fabric, a woven fabric, a resin impregnation of a soft porous body, and a soft porous body.

[0030] [5] The anti-electrolytic corrosion member for a rolling bearing according to any one of [1] to [4], wherein the elastic portion of the spring plate is bent in the middle.

[0031] [6] The anti-electrolytic corrosion member for a rolling bearing according to any one of [1] to [4], wherein the elastic portion of the spring plate is formed flush with the annular portion.

[0032] The above-mentioned object of the present invention is achieved by the following [7] structure of the anti-electrolytic corrosion rolling bearing unit.

[0033] [7] An anti-electro-corrosion rolling bearing unit, characterized in that:

[0034] The anti-electrolytic rolling bearing unit comprises an inner ring rotating type rolling bearing, wherein the outer ring of the rolling bearing is fixed to a seat body, and a shaft directly connected to a motor is embedded in the inner ring of the rolling bearing.

[0035] Furthermore, the anti-electrolytic corrosion member for a rolling bearing as described in any one of [1] to [6] is attached to the anti-electrolytic corrosion rolling bearing unit.

[0036] Hereinafter, the “anti-electrolytic corrosion member for rolling bearing” will be simply referred to as the “anti-electrolytic corrosion member”, and the “anti-electrolytic corrosion rolling bearing unit” will be simply referred to as the “bearing unit”.

[0037] Effects of the Invention

[0038] The anti-electrolytic corrosion member of the present invention is a member in which a soft conductive member attached to the elastic part of a spring plate is brought into contact with the end face of a shaft. The force applied by the soft conductive member implemented by the spring plate to the end face of the shaft is not too large, and abrasion powder is not easily generated. Moreover, the soft conductive member is made of a soft material, so the shaft as the counterpart member is less damaged.

[0039] In addition, there is no need to perform 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, so it has high versatility. Moreover, the spring plate is a thin plate, which can minimize the increase in the space of the attached bearing unit.

[0040] The bearing unit of the present invention is equipped with the anti-electro-corrosion component of the present invention, so it can suppress the generation of wear powder and damage to the other component, and it has high versatility and does not cause an increase in space. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 An example of the anti-electrolytic corrosion member of the present invention is shown. Figure 1 (A) is a top view of the anti-corrosion component, Figure 1 (B) is Figure 1 The A-A section view of (A), Figure 1 (C) means Figure 1 (B) is an enlarged view of the bent portion of the elastic portion.

[0042] Figure 2 It means that the connection is Figure 1 A cross-sectional view of an example of a bearing unit of an anti-corrosion member is shown.

[0043] Figure 3 It means in Figure 2 FIG. 4 is a diagram showing a state in which the anti-electrolytic corrosion member is pressed against the outer ring by the pressing member.

[0044] Figure 4 The anti-corrosion member of the modified example of the present invention is Figure 1 (B) corresponds to the cross-sectional view.

[0045] Figure 5 It means that the connection is Figure 4 A cross-sectional view of an example of a bearing unit of an anti-corrosion member is shown.

[0046] Description of Reference Numerals

[0047] 1: Anti-electrocorrosion components;

[0048] 10: Spring plate;

[0049] 11: annular part;

[0050] 12: Inner peripheral end;

[0051] 13: elastic part;

[0052] 14: elastic base;

[0053] 15: peripheral end surface;

[0054] 20: Soft conductive components;

[0055] 30: spacer;

[0056] 50: bearing;

[0057] 51: outer ring;

[0058] 52: inner circle;

[0059] 52a, 60a: end surface;

[0060] 53: rolling element;

[0061] 54: cage;

[0062] 60: axis;

[0063] 70: base body;

[0064] 80: pressing member;

[0065] 100: Bearing unit. DETAILED DESCRIPTION

[0066] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments described below, and can be arbitrarily modified and implemented within the scope of the present invention.

[0067] Figure 1 An example of the anti-electrolytic corrosion member of the present invention is shown. Figure 1 (A) is a top view of the anti-corrosion component, Figure 1 (B) is Figure 1 The A-A section view of (A), Figure 1 (C) means Figure 1 (B) is an enlarged view of the annular portion and the bent portion of the elastic portion. Figure 2 is a cross-sectional view showing an example of a bearing unit of the present invention, but with Figure 1 The anti-galvanic corrosion component shown.

[0068] exist Figure 2In the bearing unit 100 shown, the rolling bearing 50 is not limited, and a plurality of rolling elements (balls) 53 are held by a retainer 54 between an outer ring 51 and an inner ring 52 so as to roll freely, and the rolling bearing 50 is lubricated by a lubricating oil or a grease composition. Here, the rotating ring is the inner ring 52, and a shaft 60 directly connected to a motor not shown is embedded. The shaft 60 is embedded in a manner that the end face 60a is flush with the end face 52a of the inner ring 52. In addition, the outer ring 51 is a fixed ring, which is fixed to the seat body 70.

[0069] like Figure 1 As shown, the anti-electro-corrosion member 1 includes a spring plate 10, wherein the spring plate 10 includes a circular ring portion 11 and an elastic portion 13, and the elastic portion 13 extends from an inner peripheral end 12 of the circular ring portion 11 toward the center of the circular ring portion 11. Figure 2 As shown, when attached to the bearing unit 100 , the elastic portion 13 is bent toward the right side in the figure starting from the elastic base 14 so as to face the end surface 60 a of the shaft 60 fitted into the inner ring 52 of the rolling bearing 50 .

[0070] The entire spring plate 10 is made of a thin plate made of a conductive material such as metal. When the conductive material is metal, stainless steel is preferred for reasons such as easy processing and less rust.

[0071] A soft conductive member 20 is attached to the top end portion of the elastic portion 13, i.e., the center portion of the annular portion 11, on the surface opposite to the end surface 60a of the shaft 60 embedded in the rolling bearing 50, and the spring plate 10 and the soft conductive member 20 constitute the anti-electrolytic corrosion member 1. The soft conductive member 20 is attached to the elastic portion 13 using an adhesive.

[0072] The soft conductive component 20 is a component in which a conductive material is mixed or carried in a soft base material. As the soft base material, porous bodies such as paper, cloth, non-woven fabrics, resin sheets, etc. can be used. As the conductive material, metal fibers, metal crushed materials, and metal powders of silver, copper, gold, aluminum, stainless steel, etc., or conductive carbon fibers, conductive carbon crushed materials, and conductive carbon powders can be listed. In addition, the soft conductive component can also use a commercially available component called a "conductive sheet". Among them, the soft conductive component is preferably composed of at least one selected from a resin impregnation of a non-woven fabric, a resin impregnation of a non-woven fabric, a woven fabric, a resin impregnation of a soft porous body such as a sponge, and a soft porous body such as a sponge.

[0073] In addition, if Figure 1As shown in (C), the bending angle θ between the annular portion 11 and the elastic portion 13 is appropriately set so that the soft conductive member 20 abuts against the end face 60a of the shaft 60 when attached to the bearing unit 100. The bending angle θ can also adjust the force applied by the soft conductive member 20 to the end face 60a of the shaft 60. By reducing the bending angle θ, the applied force can be increased, and conversely, by increasing the bending angle θ, the applied force can be reduced.

[0074] It should be noted that the plane shape of the soft conductive member 20 is not limited except that it can be Figure 1 In addition to the circular shape shown in (A), it can also be a rectangle. In addition, it can also be a plurality of small pieces.

[0075] In addition, in this embodiment, if Figure 3 As shown, the annular portion 11 of the anti-electrolytic corrosion member 1 is pressed against the side surface of the outer ring 51 via the conductive spacer 30 by the conductive pressing member 80. The spacer 30 may be set to a thickness that takes into account the pressing amount of the spring plate 10, the thickness of the soft conductive member 20, etc. In addition, the annular portion 11 of the anti-electrolytic corrosion member 1 may be directly abutted against the side surface of the outer ring 51 without providing the spacer 30.

[0076] In such an inner ring rotating type bearing unit 100, usually, the current from the motor flows to the inner ring 52 via the shaft 60, and energizes the rolling element 53 and the outer ring 51 inside the bearing, so that the rolling bearing 50 is electrolytically corroded. Therefore, in the present invention, the electrolytic corrosion prevention member 1 is attached to the seat body 70 in such a manner that the soft conductive member 20 abuts against the end face 60a of the shaft 60. In addition, the annular portion 11 is electrically in contact with the side surface of the outer ring 51 via the conductive spacer 30, and is also electrically in contact with the conductive pressing member 80.

[0077] As a result, the current from the shaft 60 will flow from the soft conductive component 20 to the elastic portion 13 and the annular portion 11 of the spring plate 10, and flow to the seat body 70 through the outer peripheral end surface 15 of the annular portion 11, the pressing component 80, the spacer 30 and the outer ring 51, so that no electricity will be passed through the inside of the bearing and no electrical corrosion will occur in the rolling bearing 50.

[0078] It should be noted that the contact area between the outer ring 51 and the seat body 70 is large, so the current flowing to the outer ring 51 does not pass through the rolling element 53 but flows to the seat body 70 .

[0079] In addition, in the present embodiment, the outer peripheral end surface 15 of the annular portion 11 and the spacer 30 abut against the seat body 70, but it is also possible to have a configuration in which the outer peripheral end surface 15 of the annular portion 11 and the spacer 30 do not abut against the seat body 70 but are clamped by the pressing member 80 between the pressing member 80 and the outer ring 51. In this case, the current flowing to the annular portion 11 flows to the seat body 70 via the outer ring 51 and the pressing member 80.

[0080] Furthermore, since the end surface 60 a of the shaft 60 is in contact with the soft conductive member 20 , the end surface 60 a of the shaft 60 is not damaged, and a decrease in the rotation torque of the shaft 60 can be suppressed.

[0081] Furthermore, the base material of the soft conductive member 20 is a porous body, which has oil absorption and oil retention properties, so it is not easy to form an oil film, and the conductivity is good even when used in oil. It should be noted that by making the base material of the soft conductive member 20 a porous body, the friction coefficient can be suppressed even when used in an environment other than an oil environment, and the rotation torque of the inner ring 52 can be suppressed.

[0082] Furthermore, the soft conductive member 20 preferably abuts against the end surface 60 a of the shaft 60 near the center of the shaft. Since the peripheral speed near the center of the shaft is low, abrasion powder is less likely to be generated.

[0083] Furthermore, the spring plate 10 of the anti-corrosion member 1 is a thin plate, which can minimize the increase in the space of the bearing unit 100. In addition, since there is no restriction on the rolling bearing 50 and no processing is required, it can be applied to existing rolling bearings and has high versatility.

[0084] By increasing the contact area between the soft conductive member 20 of the anti-electrocorrosion member 1 and the end face 60a of the shaft 60 of the rolling bearing 50, the electric corrosion of the rolling bearing 50 can be more effectively prevented. The spring plate 10 is made of a bent thin plate as a whole and is an elastic member. Therefore, by pressing the annular portion 11 of the anti-electrocorrosion member 1 toward the outer ring 51, the elastic force generated by the pressing acts on the elastic portion 13. Figure 1 The elastic portion 13 is stretched so that the bending angle θ shown in (C) becomes larger, and the elastic portion 13 as a whole moves toward the rolling bearing 50 side. Figure 2 The portion of the soft conductive member 20 that is away from the end surface 60 a of the shaft 60 also moves toward the rolling bearing 50 side, and substantially the entire soft conductive member 20 comes into contact with the end surface 60 a of the shaft 60 .

[0085] It should be noted that the present invention is not limited to the above-mentioned embodiments, and appropriate modifications and improvements can be made.

[0086] For example, in the above-mentioned embodiment, the elastic portion 13 of the spring plate 10 is bent in the middle, but it may be formed flush with the annular portion 11 without being bent at the elastic base 14. Figure 4 As shown, the annular portion 11 and the elastic portion 13 are continuous in a straight line when viewed from the side.

[0087] Therefore, in Figure 5In the bearing unit 100 shown, when the annular portion 11 of the anti-electrocorrosion member 1 is clamped between the flange portion 71 of the seat body 70 and the side surface of the outer ring 51, the elastic portion 13 of the anti-electrocorrosion member 1 is elastically deformed by the thickness of the soft conductive member 20, and the soft conductive member 20 is brought into contact with the end surface 60a of the shaft 60 by the bending reaction force of the spring plate 10. Thus, the same function as the above-mentioned embodiment can be achieved.

[0088] In this case, since the bending process of the spring plate 10 is unnecessary, the electrolytic corrosion preventing member 1 can be manufactured at low cost, and the spring plate 10 and the soft conductive member 20 can be easily bonded.

[0089] Furthermore, in the present embodiment, the spring plate has a structure including one elastic portion extending toward the center of the annular portion, but may also have a structure including a plurality of elastic portions extending radially toward the center of the annular portion.

Claims

1. An anti-electrolytic corrosion component for a rolling bearing, which is attached to a rolling bearing unit having an inner ring rotating type rolling bearing so as to prevent the electric corrosion of the rolling bearing in the rolling bearing unit, wherein the outer ring of the rolling bearing is fixed to a seat body, and a shaft directly connected to a motor is embedded in the inner ring of the rolling bearing, and the anti-electrolytic corrosion component for a rolling bearing is characterized in that it has: The spring plate comprises a circular ring portion and an elastic portion, wherein the spring plate is made of a thin plate of a conductive material, The elastic portion is continuous from the inner peripheral end of the annular portion and extends toward the center of the annular portion; and a soft conductive member attached to the surface of the elastic portion on the side opposite to the rolling bearing, Furthermore, the soft conductive member can abut against the end surface of the shaft.

2. The anti-electro-corrosion member for a rolling bearing according to claim 1, characterized in that: The annular portion is pressed against the side surface of the outer ring in a manner interposing a spacer.

3. The anti-electro-corrosion 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 nonwoven fabric impregnated with resin, a nonwoven fabric, a woven fabric impregnated with resin, a woven fabric, a soft porous body impregnated with resin, and a soft porous body.

4. The anti-electro-corrosion member for a rolling bearing according to claim 2, characterized in that: The soft conductive member is composed of at least one selected from a nonwoven fabric impregnated with resin, a nonwoven fabric, a woven fabric impregnated with resin, a woven fabric, a soft porous body impregnated with resin, and a soft porous body.

5. The anti-electro-corrosion member for a rolling bearing according to claim 1, characterized in that: The elastic portion of the spring plate is bent midway.

6. The anti-electro-corrosion member for a rolling bearing according to claim 1, characterized in that: The elastic portion of the spring plate is formed to be flush with the annular portion.

7. An anti-electro-corrosion rolling bearing unit, characterized in that: An inner ring rotating type rolling bearing is provided, wherein the outer ring of the rolling bearing is fixed to a seat body, and a shaft directly connected to a motor is embedded in the inner ring of the rolling bearing. Furthermore, the anti-electrolytic corrosion member for a rolling bearing according to any one of claims 1 to 6 is attached to the anti-electrolytic corrosion rolling bearing unit.

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