Electricity supply unit, electric corrosion prevention bearing device, and bearing unit

Abstract

The energizing unit (1) is configured to have: a conductive annular housing main body (2) fitted into the housing (6); a conductive energizing member (3) that protrudes radially inward from the housing main body (2), is in sliding contact with the motor shaft (5); and an elastic member (4) that urges the energizing member (3) toward the motor shaft (5). A conductive energizing member (3) that protrudes radially inward from the housing body (2), is in sliding contact with the motor shaft (5), and has electrical conductivity; a radial elastic member (16) that urges the energizing member (3) radially inward; and a pressing mechanism (17) that presses the energizing member (3) from one side in the axial direction toward the other side in the axial direction. The bearing unit (A) has an energizing unit (1) and a bearing (7).

Description

Technical Field

[0001] The present invention relates to an energizing unit for a bearing attached to a rotating shaft such as a motor shaft, a bearing device for preventing electro-erosion using the energizing unit, and a bearing unit. Background Technology

[0002] Bearings that support rotating shafts such as motor shafts are typically rolling bearings, especially ball bearings. In recent years, frequency converters have been commonly used to enable motors to operate efficiently. Especially in the case of motors used in vehicles, miniaturization has been achieved from the perspective of vehicle compatibility, and more precise control is required to make the miniaturized motors more efficient.

[0003] It is known that shaft current and shaft voltage are generated on the motor shaft. If this current passes through the inside of the bearing, electrolytic corrosion may sometimes occur in the metal raceways and rolling elements. Therefore, for example, in Patent Document 1 below, the wire 30 (grounding brush) is brought into contact with the shaft 16 of the motor 12, and the charge generated in the shaft 16 is released to the housing via the wire 30, so that the current does not pass through the inside of the bearing (see Fig. 2 of Patent Document 1, etc.). In addition, in Patent Document 2 below, the outlet body 8 (region 10) is brought into contact with the shaft 68, and the charge generated in the shaft 68 is released to the housing 69 via the outlet body 8, so that the current does not pass through the inside of the bearing (see Fig. 24 of Patent Document 2, etc.).

[0004] Patent Document 1: US Patent No. 8,199,453

[0005] Patent Document 2: Japanese Patent No. 7033538

[0006] In the structures shown in Patent Documents 1 and 2, the charge is released by making the sliding contact parts (wire 30, guide body 8) slide into contact with the motor shafts (shaft 16, shaft 68). Therefore, the electrical conductivity may be reduced and the anti-electro-erosion effect may be insufficient due to wear, deformation, etc. of the sliding contact parts over time. Summary of the Invention

[0007] The problem to be solved by the present invention is to provide an electrical conduction unit, an anti-electro-erosion bearing device, and a bearing unit that can maintain the anti-electro-erosion effect (electrical conduction performance) for a long time and stably perform the electrical conduction performance.

[0008] To address the aforementioned issues, the first invention of this application employs the following structure (first structure), namely,

[0009] An energized unit having:

[0010] The ring-shaped main body of the shell is embedded in the outer shell and is conductive;

[0011] An electrically conductive component protrudes radially inward from the main body of the housing and slides in contact with the motor shaft, and is conductive; and

[0012] The elastic member applies force to the energized component toward the motor shaft.

[0013] Thus, the newly formed bypass path that allows current to flow from the motor shaft to the housing prevents electrolytic corrosion of the bearing located between the motor shaft and the housing. Furthermore, by applying force to the energized component towards the motor shaft through the elastic member, the contact between the motor shaft and the energized component can be maintained even as the energized component wears over time, thus sustaining the anti-electrolytic corrosion effect for a long period.

[0014] Based on the first structure, the preferred structure is the following (second structure), namely,

[0015] The main body of the housing has an annular outer ring and a retainer that fits into the outer ring. The retainer has multiple bends that are equally spaced in the circumferential direction from the aforementioned energized components.

[0016] In this way, by using the elastic component to apply a radially inward force to the electrically conductive components housed between multiple bends, a self-aligning function can be achieved, thus stabilizing the contact state between the motor shaft and the electrically conductive components.

[0017] Based on the second structure, the preferred structure is the following (third structure), namely,

[0018] The aforementioned elastic component is a spring component that spans the aforementioned multiple electrically conductive components.

[0019] In this way, multiple energized components can be simultaneously forced toward the motor shaft through a simple structure.

[0020] Based on the first to third structures, the preferred structure is the following (fourth structure), namely:

[0021] The aforementioned electrically conductive components are made of metal, carbon, or resins, rubber, ceramics, or composite materials thereof that impart conductivity.

[0022] In this way, the power supply function of the power supply unit can be ensured through a simple structure.

[0023] In the energizing units involved in the first to fourth structures, the following structure (the fifth structure) can be adopted, namely,

[0024] An anti-electro-erosion bearing device includes: an energizing unit; and a bearing, the end face of which is configured as an outer ring abuts against the energizing unit and supports a motor.

[0025] To address the aforementioned issues, the second invention of this application employs the following structure (sixth structure), namely:

[0026] An energized unit having:

[0027] The annular main body of the shell is embedded in the outer shell, forming a circumferential groove that opens toward the inner diameter side and is conductive;

[0028] The energized component is disposed in the aforementioned peripheral groove, protrudes radially inward from the aforementioned housing body and slides in contact with the motor shaft, and is conductive;

[0029] A radially elastic member, disposed within the aforementioned peripheral groove, applies a force radially inward to the aforementioned energized member; and

[0030] The pressing mechanism presses the energized component from one side to the other in the axial direction within the aforementioned circumferential groove.

[0031] Thus, the newly formed bypass path that allows current to flow from the motor shaft through the energized component and the housing body to the outer casing prevents electrolytic corrosion of the bearings located between the motor shaft and the housing. Furthermore, by applying force to the energized component toward the motor shaft via the radial elastic member, even as the energized component wears over time, the contact between the motor shaft and the energized component is maintained, ensuring long-term energization performance. Moreover, by pressing the energized component from one side of the axial direction to the other via the pressing mechanism, the contact between the energized component and the housing body is maintained, resulting in stable energization performance.

[0032] Based on the sixth structure, a preferred structure (seventh structure) is one in which the pressing mechanism is a buckled portion formed on at least one of the pair of wall portions constituting the peripheral groove and buckles toward the inner side of the peripheral groove relative to the outer diameter side. Alternatively, a preferred structure (eighth structure) is one in which the pressing mechanism is an axially elastic member sandwiched in the axial gap between the inner surface of the peripheral groove and the energized component. Alternatively, a preferred structure (tenth structure) is one in which the pressing mechanism is formed on the contact portion of the energized component that abuts against the radially elastic member and has an inclined surface portion with a normal inclined toward one side of the axial direction. By adopting the above structures, the energized component can be pressed from one side of the axial direction to the other, and the contact state between the energized component and the housing body can be reliably maintained.

[0033] Furthermore, based on the eighth structure, a preferred structure (ninth structure) is one in which the aforementioned axial elastic member is made of a conductive material, such as metal, carbon, or a conductive resin, rubber, ceramic, or a composite material thereof. This ensures that multiple current-carrying lines—both those directly from the energized member to the main body of the housing and those flowing from the energized member to the main body of the housing via the axial elastic member—are maintained, thus enabling more stable current-carrying performance.

[0034] Based on structures six through ten, a preferred structure (structure eleven) is provided, in which multiple energized components are provided. In this way, even if the energizing performance of some energized components is impaired, it can be compensated for by other energized components, thus ensuring stable energizing performance.

[0035] Based on the eleventh structure, a preferred structure (twelfth structure) is one in which the main body of the housing has an annular outer ring and a retainer that fits into the outer ring. The retainer has multiple bends at equal intervals in the circumferential direction for equidistant components. In this way, by applying radially elastic force to the energized components housed between the multiple bends, a self-aligning function is achieved, stabilizing the contact between the motor shaft and the energized components.

[0036] Based on the sixth structure, a preferred structure (the thirteenth structure) is one in which the radial elastic member is a metal spring member that spans the plurality of energized members. In this way, a simple structure can be used to apply force to the multiple energized members simultaneously toward the motor shaft.

[0037] Based on structures six through thirteen, a preferred structure (structure fourteen) is one in which the aforementioned energized component is made of a conductive material such as metal, carbon, or a conductive resin, rubber, ceramic, or a composite material thereof. This ensures the energizing performance of the energized unit through a simple structure.

[0038] In the energizing unit involved in the sixth to fourteenth structures, the following structure (fifteenth structure) can be adopted, namely, a bearing unit having: an energizing unit; and a bearing having an outer ring, an inner ring disposed on the inner diameter side of the outer ring, a rolling element disposed between the outer ring and the inner ring, and a retainer that holds the rolling element at a predetermined interval in the circumferential direction, configured such that the outer ring abuts against the energizing unit and supports the motor shaft.

[0039] According to the energizing unit of the first invention of this application, a new bypass path is formed to allow current to flow from the motor shaft to the housing, thereby preventing electro-erosion of the bearing disposed between the motor shaft and the housing. Furthermore, by applying force to the energizing component toward the motor shaft through the elastic member, even if the energizing component wears over time, the contact state between the motor shaft and the energizing component can be maintained, thus sustaining the anti-electro-erosion effect of the bearing anti-electro-erosion device for a long period of time.

[0040] Furthermore, according to the second invention of this application, the energizing unit and the bearing unit employing the energizing unit form a new bypass path for current to flow from the motor shaft to the housing, thus preventing electro-erosion of the bearing disposed between the motor shaft and the housing. Additionally, by applying force to the energizing component toward the motor shaft via the radial elastic member, even if the energizing component wears over time, the contact state between the motor shaft and the energizing component can be maintained, thus sustaining the anti-electro-erosion effect of the bearing device for a long period. Moreover, by pressing the energizing component from one side of the axial direction to the other via the pressing mechanism, the contact state between the energizing component and the housing body can be maintained, resulting in stable energizing performance. Attached Figure Description

[0041] Figure 1 This is a cross-sectional view showing one embodiment of an anti-electro-erosion bearing device employing the energizing unit involved in the first invention of this application.

[0042] Figure 2 It is along Figure 1 A sectional view along line II-II in the diagram.

[0043] Figure 3 yes Figure 1 An exploded perspective view of the energized unit shown.

[0044] Figure 4 This is a cross-sectional view showing one embodiment of a bearing unit employing the power supply unit involved in the second invention of this application.

[0045] Figure 5 It is along Figure 4 A cross-sectional view of the VV line.

[0046] Figure 6 yes Figure 4 A cross-sectional view of the main part of the energized unit shown.

[0047] Figure 7 yes Figure 4 An exploded perspective view of the energized unit shown.

[0048] Figure 8 yes Figure 4 A cross-sectional view of the main part of the first modified example of the energized unit shown.

[0049] Figure 9 yes Figure 4 A cross-sectional view of the main part of the second modified example of the energized unit shown.

[0050] Figure 10 yes Figure 4 A cross-sectional view of the main part of the third variant of the energized unit shown.

[0051] Figure 11 yes Figure 4 A cross-sectional view of a modified example of the bearing unit shown. Detailed Implementation

[0052] The anti-electro-erosion bearing device A, which employs the energizing unit 1 according to the first invention of this application, is shown in the attached figure. Figures 1-3 As shown, the energizing unit 1 mainly consists of a housing body 2, an energizing component 3, and an elastic component 4. The energizing unit 1 is sandwiched between the motor shaft 5 and the housing 6, so as to be adjacent to a bearing 7 (a ball bearing in this embodiment), which is sandwiched between the motor shaft 5 (e.g., the axle) and the housing 6 and supports the motor shaft 5. The housing 6 is electrically grounded.

[0053] From the perspective of preventing electrolytic corrosion, such as Figure 1 As shown, the energizing unit 1 and the bearing 7 are preferably arranged in axial contact, but a structure with a gap between them is also permissible. Hereinafter, the direction along the rotation axis of the motor shaft 5 will be referred to as the axial direction, the direction perpendicular to the rotation axis will be referred to as the radial direction, and the direction along the circumference of the rotation axis will be referred to as the circumferential direction.

[0054] The housing body 2 is a conductive annular component embedded in the inner diameter surface of the outer casing 6. The housing body 2 consists of an annular outer ring 8 with a flange extending in one axial direction on its outer periphery, and a retainer 9 with a flange extending in the opposite direction to the aforementioned axial direction on its outer periphery. Figure 1 As shown, the flange formed on the outer ring portion 8 and the flange formed on the retainer 9 are integrated by press-fitting. Furthermore, after inserting the flange formed on the retainer 9 into the flange formed on the outer ring portion 8, a retaining ring can be provided on the width surface to fix the outer ring portion 8 and the retainer 9, thereby improving maintainability.

[0055] Both the outer ring 8 and the retainer 9 are made of steel. An axial gap is formed between the fitted outer ring 8 and the retainer 9 to accommodate the energized component 3 and the elastic component 4. In the retainer 9, a plurality of (four in this embodiment) bent portions 10 are formed at predetermined angular intervals, extending from its inner edge in the aforementioned other axial direction (the same direction as the flange formed on the retainer 9).

[0056] The energizing component 3 is a conductive, arc-shaped component that protrudes radially inward from the housing body 2 and slides in contact with the motor shaft 5 supported by the bearing 7. The energizing components 3 are housed one by one between adjacent circumferentially adjacent bends 10 formed in the retainer 9. In this embodiment, four energizing components 3 are arranged at equal intervals in the circumferential direction. The number of energizing components 3 can be appropriately varied, but is preferably multiple. The number of bends 10 formed in the retainer 9 is determined corresponding to the number of energizing components 3. In this embodiment, polytetrafluoroethylene (PTFE) with added carbon is used as the raw material for the energizing components 3. The inner diameter surface of the energizing component 3 is formed by a portion of a cylindrical surface and contacts the outer circumferential surface of the motor shaft 5. A circumferential groove 11 is formed on the outer periphery of the energizing component 3.

[0057] As the raw material for the electrically conductive component 3, in addition to PTFE with added carbon, other materials such as metals, carbon, or carbon-added polyether ether ketone (PEEK) resins, rubbers, ceramics, or composite materials thereof that impart conductivity can also be used. In addition, surface processing such as coatings (e.g., conductive diamond-like carbon (DLC) films, metal films (platings, etc.)) can be applied to the surface of the electrically conductive component 3 (especially the inner diameter surface that slides in contact with the motor shaft 5) to improve conductivity and wear resistance.

[0058] The elastic component 4 is used to apply force to the energized component 3 radially inward toward the motor shaft 5 (see reference). Figure 2 The component with the arrow in it. For example... Figure 2 As shown, the elastic member 4 is mounted across the circumferential groove 11 formed on the outer periphery of each energized member 3. In this embodiment, a clamping disc spring formed by machining a coiled steel wire into a ring is used as the elastic member 4, but for example, a retaining ring (C-shaped retaining ring) with a slit in a part of the ring, or a ring-shaped rubber ring, can also be used. Furthermore, in this embodiment, a structure is adopted in which force is applied to all energized members 3 by one elastic member 4, but a structure in which an elastic member 4 is provided separately for each energized member 3 can also be adopted.

[0059] The function of the energizing unit 1 will be explained. A motor shaft 5 is inserted through the center of the energizing unit 1. If, as the motor shaft 5 rotates, the inner diameter surface of the energizing component 3, which is subjected to force by the elastic member 4 towards the motor shaft 5, slides into contact with the motor shaft 5, the inner diameter surface will gradually wear down. Even with this wear, the energizing component 3 is always subjected to force by the elastic member 4 towards the motor shaft 5, thus maintaining the contact state (energized state) between the motor shaft 5 and the energizing component 3.

[0060] The energized component 3 contacts the housing body 2 (at least one of the outer ring 8 or the cage 9), forming an energized circuit as a bypass between the motor shaft 5, the energized component 3, the housing body 2, and the outer casing 6. By forming such an energized circuit, the current through the bearing 7 sandwiched between the motor shaft 5 and the outer casing 6 is reduced, thus preventing electrolytic corrosion of the components of the bearing 7.

[0061] The aforementioned energizing unit 1 releases the charge generated in the motor shaft 5 to the outer casing 6 via the energizing component 3 and the main body 2, thus preventing electrolytic corrosion of the bearing 7 located between the motor shaft 5 and the outer casing 6. Furthermore, by applying force to the energizing component 3 radially inward, i.e., towards the motor shaft 5, through the elastic component 4, even if the energizing component 3 wears over time, the contact between the motor shaft 5 and the energizing component 3 can be maintained, thus sustaining the anti-electrolytic corrosion effect for a long period. In addition, the energizing component 3 uses a component with an initial radial width that can withstand long-term use even if wear occurs over time.

[0062] Furthermore, in the aforementioned energizing unit 1, the inner diameter surface of the energizing component 3 is brought into contact with the outer peripheral surface of the motor shaft 5 to ensure a wide energizing area. This increases the amount of current released from the motor shaft 5 to the housing 6 via the energizing unit 1, and more effectively prevents electrolytic corrosion of the bearing 7.

[0063] Furthermore, in the aforementioned energizing unit 1, by providing multiple energizing components 3, even if a fault occurs in which the energizing function of some energizing components 3 is impaired, the energizing function can be ensured by the other energizing components 3, thus reliably achieving the effect of preventing electro-erosion. Additionally, by utilizing the self-aligning function based on the multiple energizing components 3, the contact state between the motor shaft 5 and each energizing component 3 can be stabilized, thereby further improving the effect of preventing electro-erosion.

[0064] Furthermore, in the above-described embodiments, a structure is adopted in which the motor shaft 5 is inserted through the axis of the energizing unit 1 and the energizing component 3 is subjected to radial inward force by the elastic member 4, thereby making the energizing component 3 and the motor shaft 5 slide in contact. However, in the opposite case, when the motor shaft 5 is provided on the outer diameter side of the energizing unit 1 and the housing 6 is provided on the inner diameter side of the energizing unit 1, a structure in which the elastic member 4 is used to apply radial outward force to the energizing component 3 can also be adopted.

[0065] An embodiment of the bearing unit A (anti-electro-erosion bearing device) of the energized unit 1 according to the second invention of this application is as follows: Figure 4As shown. Bearing unit A consists of energizing unit 1 and bearing 7 (a ball bearing in this embodiment). Bearing 7 has: an outer ring 12, an inner ring 13 disposed on the inner diameter side of the outer ring 12, rolling elements 14 disposed between the outer ring 12 and the inner ring 13, and a retainer 15 that holds the rolling elements 14 at predetermined intervals in the circumferential direction. The energizing unit 1 and the outer ring 12 of the bearing 7 abut against each other.

[0066] like Figures 4-7 As shown, the main components of the energizing unit 1 are the housing body 2, the energizing component 3, the radial elastic component 16, and the pressing mechanism 17. The energizing unit 1 is disposed between the motor shaft 5 and the housing 6, adjacent to the bearing 7, which is disposed between the motor shaft 5 (e.g., the axle) and the housing 6 and supports the motor shaft 5. The housing 6 is electrically grounded. Hereinafter, the direction along the rotation axis of the motor shaft 5 will be referred to as the axial direction, the direction perpendicular to the rotation axis will be referred to as the radial direction, and the direction along the circumference of the rotation axis will be referred to as the circumferential direction.

[0067] The housing body 2 is a conductive annular component embedded in the outer shell 6. The housing body 2 has: an annular outer ring 8 having a flange 18 extending axially along its outer periphery and an extension piece 19 extending radially inward from its outer periphery; and an annular retainer 9 having a flange 20 extending axially inward in a direction opposite to the aforementioned axial direction along its outer periphery and an extension piece 21 extending radially inward from its outer periphery. Figure 4 As shown, the flange 18 formed in the outer ring portion 8 and the flange 20 formed in the retainer 9 are integrated by press-fitting. With this integration, a circumferential groove opening toward the inner diameter side is formed by the flanges 18 and 20 formed in the outer ring portion 8 and the retainer 9, respectively, and the extended plates 19 and 21. Furthermore, after the flange 20 formed in the retainer 9 is inserted into the flange 18 formed in the outer ring portion 8, a retaining ring can be provided on the width surface to fix the outer ring portion 8 and the retainer 9, thereby improving maintainability.

[0068] Both the outer ring 8 and the retainer 9 are made of steel. The axial clearance of the circumferential groove formed by the integration of the outer ring 8 and the retainer 9 is set to be slightly larger than the axial width of the energized component 3, so that the energized component 3 can move freely in the radial direction. In the retainer 9, a plurality of bent portions 10 are formed at predetermined angular intervals (4 in this embodiment) extending from the inner edge of the extending plate 21 in the axial direction (the same direction as the flange 20 formed on the retainer 9).

[0069] The energizing component 3 is an arc-shaped component that is disposed within the circumferential groove, protrudes radially inward from the housing body 2, slides in contact with the motor shaft 5, and is conductive. The energizing components 3 are housed one by one between adjacent circumferentially adjacent bends 10 formed in the retainer 9. In this embodiment, four energizing components 3 are arranged at equal intervals in the circumferential direction. The number of energizing components 3 can be appropriately varied, but is preferably multiple. The number of bends 10 formed in the retainer 9 is determined corresponding to the number of energizing components 3. In this embodiment, polytetrafluoroethylene (PTFE) with added carbon is used as the raw material for the energizing component 3. The inner diameter surface of the energizing component 3 is formed by a portion of a cylindrical surface and is in surface contact with the outer circumferential surface of the motor shaft 5. An outer circumferential groove 11 (circumferential groove) is formed on the outer periphery of the energizing component 3.

[0070] As the raw material for the electrically conductive component 3, in addition to PTFE with added carbon, conductive materials such as metals, carbon, or carbon-added polyether ether ketone (PEEK) resins, rubbers, ceramics, or composites thereof can also be used. In addition, surface processing such as coatings (e.g., conductive diamond-like carbon (DLC) films, metal films (platings, etc.)) can be applied to the surface of the electrically conductive component 3 (especially the inner diameter surface that slides in contact with the motor shaft 5) to improve its electrical conductivity and wear resistance.

[0071] The radial elastic member 16 is disposed within the circumferential groove and is used to apply force to the energized member 3 radially inward (see reference). Figure 5 The component with the arrow in it. For example... Figure 5 As shown, the radial elastic member 16 is mounted across the outer peripheral groove 11 formed in each energized member 3. In this embodiment, a clamping disc spring formed by machining a coiled steel wire into a ring shape is used as the radial elastic member 16, but for example, a retaining ring (C-shaped retaining ring) with a slit in a part of the ring, or an annular rubber ring, can also be used. Furthermore, in this embodiment, a structure is adopted in which force is applied to all energized members 3 by one radial elastic member 16, but a structure in which a radial elastic member 16 is provided separately for each energized member 3 can also be adopted.

[0072] The pressing mechanism 17 is a mechanism for pressing the energized member 3 from one side of the axial direction toward the other. In this embodiment, the pressing mechanism 17 is a bent portion 17a formed in at least one of the pair of wall portions (outer ring portion 8 and the extension pieces 19, 21 of the retainer 9) constituting the circumferential groove, which bends toward the inner side of the circumferential groove on the inner diameter side relative to the outer diameter side. More specifically, the bent portion 17a is formed by tilting the extension piece 19 of the outer ring portion 8 entirely at a predetermined angle relative to the radial direction toward the inner side of the circumferential groove, starting from the connection portion with the flange 18. Furthermore, it is also possible to adopt a structure in which the bent portion 17a is formed only in the retainer 9, or a structure in which the bent portion 17a is formed in both the outer ring portion 8 and the retainer 9.

[0073] The function of the energizing unit 1 will be explained. A motor shaft 5 is inserted through the center of the energizing unit 1. If, as the motor shaft 5 rotates, the inner diameter surface of the energizing component 3, which is subjected to force by the radial elastic member 16 towards the motor shaft 5, slides into contact with the motor shaft 5, the inner diameter surface will gradually wear. Even with this wear, the energizing component 3 is always subjected to force by the radial elastic member 16 towards the motor shaft 5, thus maintaining the contact state (energized state) between the motor shaft 5 and the energizing component 3.

[0074] The energized component 3 is pressed toward the retainer 9 by the pressing mechanism 17 (the bent portion 17a formed in the extended mounting piece 19 of the outer ring portion 8). As a result, the axial clearance between the energized component 3 and the housing body portion 2 (outer ring portion 8 and retainer 9) disappears, forming an energized circuit as a bypass between the motor shaft 5, the energized component 3, the housing body portion 2, and the outer casing 6. By forming this energized circuit, the current through the bearing 7 sandwiched between the motor shaft 5 and the outer casing 6 is reduced, preventing electrolytic corrosion of the components of the bearing 7.

[0075] In the aforementioned energizing unit 1 and bearing unit A, the charge generated in the motor shaft 5 is released to the outer casing 6 via the energizing component 3 and the main body 2 of the casing, thus preventing electrolytic corrosion of the bearing 7 located between the motor shaft 5 and the outer casing 6. Furthermore, by applying force to the energizing component 3 radially inward, i.e., towards the motor shaft 5, through the radial elastic member 16, even if the energizing component 3 wears over time, the contact state between the motor shaft 5 and the energizing component 3 can be maintained, thus sustaining the anti-electrolytic corrosion effect for a long period. Moreover, as the energizing component 3, it is preferable to use a component with an initial radial width that can withstand long-term use even if wear occurs over time.

[0076] Furthermore, in the aforementioned energizing unit 1 and bearing unit A, the energizing component 3 is pressed from one side of the axial direction to the other side by the buckling portion 17a, which serves as the pressing mechanism 17. Therefore, the contact state between the energizing component 3 and the housing body 2 can be maintained, and stable energizing performance can be achieved.

[0077] Furthermore, in the aforementioned energizing unit 1 and bearing unit A, the inner diameter surface of the energizing component 3 is made to contact the outer peripheral surface of the motor shaft 5, thereby ensuring a wide energizing area. This increases the amount of current released from the motor shaft 5 to the housing 6 via the energizing unit 1, and more effectively prevents electrolytic corrosion of the bearing 7.

[0078] Furthermore, in the aforementioned energizing unit 1 and bearing unit A, by providing multiple energizing components 3, even if a fault occurs in which the energizing function of some energizing components 3 is impaired, the energizing function can be ensured by the other energizing components 3, thus reliably achieving the effect of preventing electrolytic corrosion. In addition, through the self-aligning function based on the multiple energizing components 3, the contact state between the motor shaft 5 and each energizing component 3 can be stabilized, thereby further improving the effect of preventing electrolytic corrosion.

[0079] The first variation of the energized unit 1 is as follows: Figure 8 As shown. The basic structure of the energized unit 1 involved in the first modification is the same as... Figure 4 The energizing unit 1 shown is the same as that shown, but the difference is that the bent portion 17a, which is the pressing mechanism 17, is only formed on a portion of the inner diameter front end of the extended mounting piece 19 of the outer ring portion 8. Even in this structure, the energizing member 3 can be pressed from one side to the other axially via the bent portion 17a, thus maintaining the contact state between the energizing member 3 and the housing body portion 2, and achieving stable energizing performance. Furthermore, compared with Figure 4 Similarly, the energizing unit 1 shown can also be structured such that the buckling portion 17a is formed only in the cage 9, or that the buckling portion 17a is formed in both the outer ring portion 8 and the cage 9.

[0080] The second variation of the energized unit 1 is as follows: Figure 9 As shown. The basic structure of the energized unit 1 involved in the second modification is the same as... Figure 4 The energizing unit 1 shown is the same as the others, but the difference lies in that the pressing mechanism 17 is an axially elastic member 17b sandwiched in the axial gap between the inner surface of the circumferential groove and the energizing member 3. Even in this structure, the energizing member 3 can be pressed from one side to the other axially by means of the axially elastic member 17b, thus maintaining the contact state between the energizing member 3 and the housing body 2 (outer ring 8) and achieving stable energizing performance. In the second variation, a structure in which the axially elastic member 17b is sandwiched between the retainer 9 and the energizing member 3 is adopted, but a structure in which the axially elastic member 17b is sandwiched between the outer ring 8 and the energizing member 3 can also be adopted.

[0081] In the second variation of the energizing unit 1, a structure can also be adopted in which the axial elastic member 17b is made of a conductive material such as metal, carbon, or a conductive resin, rubber, ceramic, or a composite material thereof. In this way, multiple energizing lines can be ensured, namely, the energizing line where current flows directly from the energizing member 3 to the housing body 2 (outer ring 8), and the energizing line where current flows from the energizing member 3 to the housing body 2 (cage 9) via the axial elastic member 17b, thus enabling more stable energizing performance.

[0082] The third variation of the energized unit 1 is, for example Figure 10 As shown. The basic structure of the energized unit 1 involved in the third variation is the same as... Figure 4 The energizing unit 1 shown is the same as the others, but differs in that the pressing mechanism 17 is an inclined surface 17c formed on the contact portion of the energizing member 3 with the radial elastic member 16, having a normal inclined to one side in the axial direction. The inclined surface 17c is inclined such that the closer it is to the motor shaft 5, the further it moves from the outer ring portion 8 towards the holder 9. When the radial elastic member 16 contacts the inclined surface 17c, the radial component of the contact force acts as a force pressing the energizing member 3 against the motor shaft 5, and the axial component acts as a force pressing the energizing member 3 against the extended mounting piece 19 of the outer ring portion 8.

[0083] In this way, by tilting the face 17c, the force of the radial elastic member 16 is branched into radial and axial components, thereby maintaining the contact state between the energized member 3 and the motor shaft 5, and between the energized member 3 and the housing body 2 (outer ring 8), thus achieving stable energizing performance. Furthermore, with... Figure 10 The structure shown, conversely, also allows the inclined face 17c to tilt in a manner that is closer to the motor shaft 5 the further away from the cage 9 side toward the outer ring 8 side.

[0084] In the energized unit 1 involved in the third variation, and Figure 4 Similarly, the radial elastic member 16 of the energizing unit 1 shown is preferably made of metal. In this way, multiple power lines can be ensured, namely the power lines through which current flows directly from the energizing member 3 to the housing body 2 (outer ring 8) and the power lines through which current flows from the energizing member 3 to the housing body 2 (cage 9) via the radial elastic member 16, thus enabling more stable power-carrying performance.

[0085] Deformation of bearing unit A, for example Figure 11 As shown. The basic structure of bearing unit A involved in this variation is the same as... Figure 4 The bearing unit A shown is common, but differs in that, in this bearing unit A, the energizing unit 1 and the bearing 7 are independent components. In contrast, in the bearing unit A involved in the modified example, the energizing unit 1 and the bearing 7 are... Figure 4The flange 18 of the outer ring portion 8 of the energizing unit 1 shown in the figure extends axially to the outer diameter side of the outer ring 12 of the bearing 7, thus forming an integrated bearing unit A of the energizing unit 1 and the bearing 7. In this way, it can perform with... Figure 4 The power supply unit 1 and bearing unit A shown have the same function, and the dimensions of bearing unit A are made to be common with the main dimensions of bearings standardized in the Japanese Industrial Standard (JISB1512-1:2011), thereby enabling the bearing unit A equipped with power supply unit 1 to be lightweight and narrow.

[0086] Furthermore, in the above embodiments, a structure is adopted in which the motor shaft 5 is inserted through the axis of the energizing unit 1 and the energizing component 3 is subjected to radial inward force by the radial elastic member 16, thereby making the energizing component 3 and the motor shaft 5 slide in contact. However, in the case where the motor shaft 5 is provided on the outer diameter side of the energizing unit 1 and the housing 6 is provided on the inner diameter side of the energizing unit 1, a structure in which the energizing component 3 is subjected to radial outward force by the radial elastic member 16 can also be adopted.

[0087] The embodiments disclosed herein should be considered illustrative in all respects and not intended to limit the invention. The scope of the invention is not limited by the foregoing description but is defined by the claims, which are intended to include all modifications within the meaning and scope of the claims.

[0088] In the above embodiments of the first invention of this application, such as Figure 1 As shown, the energizing unit 1 and the bearing 7 constituting the anti-electro-erosion bearing device A are separate components. However, for example, it is also possible to adopt a structure in which the flange of the outer ring portion 8 of the energizing unit 1 extends axially toward the outer ring of the bearing 7, thereby integrating the energizing unit 1 and the bearing 7.

[0089] Explanation of reference numerals in the attached figures

[0090] 1…Electrifying unit; 2…Main housing section; 3…Electrifying component; 4…Elastic component; 5…Motor shaft; 6…Housing shell; 7…Bearing; 8…Outer ring section; 9…Cage; 10…Bending section; 12…Outer ring; 13…Inner ring; 14…Rolling element; 15…Retainer; 16…Radial elastic component; 17…Pressing mechanism; 17a…Bending section; 17b…Axial elastic component; 17c…Inclined surface section.

Claims

1. A power-conducting unit, characterized in that, have: The annular main body (2) is embedded in the outer shell (6) and is conductive; The energized component (3) protrudes radially inward from the main body of the housing (2) and slides in contact with the motor shaft (5), and is conductive; and The elastic member (4) applies force to the energized member (3) toward the motor shaft (5).

2. The energizing unit according to claim 1, characterized in that, The housing body (2) has an annular outer ring (8) and a retainer (9) that fits into the outer ring (8). The retainer (9) has a plurality of bends (10) that are equally spaced in the circumferential direction for the plurality of the power-conducting components (3).

3. The energizing unit according to claim 2, characterized in that, The elastic component (4) is a spring component that spans the plurality of energized components (3).

4. The energizing unit according to any one of claims 1 to 3, characterized in that, The electrically conductive component (3) is made of a conductive material, such as metal, carbon, or a resin, rubber, ceramic, or a composite of the above.

5. A device for preventing electrolytic corrosion of bearings, characterized in that, have: The energizing unit (1) according to any one of claims 1 to 4; and The bearing (7) is configured such that the end face of the outer ring abuts against the energized unit (1) and supports the motor.

6. A power-conducting unit, characterized in that, have: The annular housing body (2) is embedded in the outer shell (6), forming a circumferential groove that opens toward the inner diameter side and is conductive; The energized component (3) is disposed in the peripheral groove, protrudes radially inward from the housing body (2) and slides in contact with the motor shaft (5), and is conductive; A radially elastic member (16) is disposed within the circumferential groove, applying a force radially inward to the energized member (3); and The pressing mechanism (17) presses the energized component (3) from one side to the other in the axial direction within the circumferential groove.

7. The energizing unit according to claim 6, characterized in that, The pressing mechanism (17) is a buckled portion (17a) formed on at least one of the pair of walls constituting the peripheral groove and buckled toward the inside of the peripheral groove on the inner diameter side relative to the outer diameter side.

8. The energizing unit according to claim 6, characterized in that, The pressing mechanism (17) is an axially elastic component (17b) sandwiched in the axial gap between the inner surface of the peripheral groove and the energized component (3).

9. The energizing unit according to claim 8, characterized in that, The axial elastic member (17b) is made of a conductive material, such as metal, carbon, or a resin, rubber, ceramic, or a composite of the above.

10. The energizing unit according to claim 6, characterized in that, The pressing mechanism (17) is formed on the contact portion of the energized component (3) that abuts against the radial elastic component (16) and has an inclined surface (17c) with a normal inclined to one side in the axial direction.

11. The energizing unit according to any one of claims 6 to 10, characterized in that, The energized component (3) is provided in multiple forms.

12. The energizing unit according to claim 11, characterized in that, The housing body (2) has an annular outer ring (8) and a retainer (9) that fits into the outer ring (8). The retainer (9) has a plurality of bends (10) that are equally spaced in the circumferential direction for the plurality of the power-conducting components (3).

13. The energizing unit according to claim 6, characterized in that, The radial elastic member (16) is a metal spring member that spans the plurality of energized members (3).

14. The energizing unit according to any one of claims 6 to 13, characterized in that, The electrically conductive component (3) is made of a conductive material, such as metal, carbon, or a resin, rubber, ceramic, or a composite of the above.

15. A bearing unit, characterized in that, have: The energizing unit (1) according to any one of claims 6 to 14; and The bearing (7) has an outer ring (12), an inner ring (13) disposed on the inner diameter side of the outer ring (12), a rolling element (14) disposed between the outer ring (12) and the inner ring (13), and a retainer (15) that holds the rolling element (14) at a predetermined interval in the circumferential direction, and is configured such that the outer ring (12) abuts against the energizing unit (1) and supports the motor shaft (5).

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