Discharge apparatus and motor

Abstract

The present disclosure relates to a discharge apparatus for a motor, and a motor. The motor comprises a housing and a rotor, and the rotor is capable of rotating relative to the housing and is provided with a rotor shaft (8). The discharge apparatus is capable of guiding charge at the rotor shaft (8) to the housing. The discharge apparatus comprises: a first conductive member (1), fixedly provided at the housing and electrically connected to the housing; a guide pipe (3), extending in the axial direction and fixedly provided at the first conductive member (1); and an electrical contact member (5), provided with an inner cavity that is axially open, the electrical contact member (5) being supported on the radial outer side of the guide pipe (3) by means of the inner cavity and being electrically connected to the first conductive member (1), wherein the electrical contact member (5) and the rotor shaft (8) form electrical contact with each other and can slide relative to each other, so that the discharge apparatus can guide the charge at the rotor shaft (8) to the housing, or the rotor shaft (8) is fixedly provided with a matched electrical contact member (7) electrically connected to the rotor shaft (8), and the electrical contact member (5) and the matched electrical contact member (7) form electrical contact with each other and can slide relative to each other, so that the discharge apparatus can guide the charge at the rotor shaft (8) to the housing.

Description

Export device and motor Technical Field

[0001] The present disclosure relates to the field of vehicle technology, and particularly to a derivation device and a motor. Background Art

[0002] Current electric motors, particularly those used to power electric or hybrid vehicles, can generate shaft voltage on the rotor shaft during operation due to various factors. To prevent static charge accumulated on the rotor shaft and rotor support from forming a current path through the bearings supporting the rotor shaft, thereby preventing pitting corrosion in components such as the bearings, a discharge device consisting of grounding carbon brushes is typically installed in the motor. Discharge devices are also commonly used in railway technology to remove current from the wheel axle.

[0003] Summary of the Invention

[0004] The object of the present disclosure is to provide a derivation device solution with an improved structure, preferably with lower manufacturing cost while ensuring the derivation function.

[0005] According to one aspect of the present disclosure, the above object is achieved by a discharge device for an electric motor, wherein the electric motor includes a housing and a rotor, wherein the rotor is rotatable relative to the housing and has a rotor shaft, and the discharge device electrically connects the rotor shaft and the housing.

[0006] According to some embodiments of the present disclosure, the derivation device includes: a first conductive member, which is fixedly arranged at the shell and electrically connected to the shell; a guide tube, which extends axially and is fixedly arranged at the first conductive member; an electrical contact member, which is constructed with an axially open inner cavity, and the electrical contact member is supported on the radial outside of the guide tube by means of the inner cavity and is electrically connected to the first conductive member, wherein the electrical contact member and the rotor shaft form an electrical contact that can slide relative to each other, so that the derivation device can guide the charge at the rotor shaft to the shell.

[0007] According to other embodiments of the present disclosure, the derivation device includes: a first conductive member, which is fixedly arranged at the shell and electrically connected to the shell; a guide tube, which extends axially and is fixedly arranged at the first conductive member; an electrical contact member, which is constructed with an axially open inner cavity, and the electrical contact member is supported on the radial outside of the guide tube by means of the inner cavity and is electrically connected to the first conductive member, wherein a mating electrical contact member electrically connected to the rotor shaft is fixedly arranged at the rotor shaft, and the electrical contact member and the mating electrical contact member form an electrical contact that can slide relative to each other, so that the derivation device can guide the charge at the rotor shaft to the shell.

[0008] The electric motor can be used, in particular, as a drive motor for electric or hybrid vehicles. The electric motor is preferably configured as an internal rotor radial motor. The electric motor essentially comprises a housing, a stator, and a rotor. The housing forms a receiving space for the stator and rotor. The stator can be fixedly arranged relative to the housing within the receiving space. The rotor is arranged radially inside the sleeve-shaped stator and can rotate relative to the housing and stator. The rotor's output torque is output via a rotor shaft, which can be supported on the housing via rolling bearings.

[0009] Within the scope of this document, unless otherwise specified, the terms “axial”, “radial” and “circumferential” are defined based on the rotation axis of the electric machine, ie the rotation axis of the rotor shaft.

[0010] The first conductive member is preferably made of a conductive metal. The first conductive member is fixed to the housing and electrically connected to the housing. The first conductive member preferably directly contacts the housing, especially a metal housing, to achieve electrical connection with the housing.

[0011] The guide tube is cylindrical in shape and preferably made of plastic to reduce the weight of the device and reduce manufacturing costs. The guide tube is fixed to the first conductive member and is supported by the first conductive member.

[0012] The electrical contact is configured as a block-shaped member having an axially open inner cavity. For example, the electrical contact is configured as a carbon brush having an axially open inner cavity. The electrical contact is essentially made of a carbon-metal mixture, particularly a mixture of graphite and a highly conductive metal. Preferably, the electrical contact is doped with copper or silver ions.

[0013] In an embodiment in which the electrical contact is in sliding contact with the rotor shaft, the electrical contact is directly electrically connected to the rotor shaft, thereby enabling a relatively low system resistance to be maintained on the charge removal path.

[0014] In embodiments where the electrical contact is in sliding contact with a mating electrical contact, the electrical contact is indirectly electrically connected to the rotor shaft via the mating electrical contact. The mating electrical contact is made of a conductive material, preferably a conductive metal. This is particularly applicable when the rotor shaft is configured as a hollow shaft and thus has a small axial end surface area. In particular, in embodiments where the discharge device is arranged substantially coaxially with the rotor shaft, the mating electrical contact electrically connected to the rotor shaft can provide a sufficient contact area for the power supply contact to make sliding contact.

[0015] Since the electrical contact is electrically connected to the first conductive member and the electrical contact is directly electrically connected to the rotor shaft due to direct sliding contact with the rotor shaft or indirectly electrically connected to the rotor shaft via sliding contact with the mating electrical contact, the charge on the rotor shaft can be discharged to the housing.

[0016] Here, the electrical contact is supported by its inner cavity on the radial outside of the guide tube, whereby the first conductive element not only realizes the electrical connection between the electrical contact and the housing as a conductor but also serves as a supporting component for the guide tube and the electrical contact.

[0017] In some preferred embodiments, the decoupling device further includes a tensioning member, which is sleeved within the guide tube and axially tensioned between the first conductive member and the electrical contact. The tensioning member is preferably a spring, particularly a helical compression spring. The first conductive member forms an abutment portion for the tensioning member, preferably having a tensioning member base that matches the shape of the tensioning member. Preferably, the axial end surface of the electrical contact facing the first conductive member serves as the abutment portion for the tensioning member. This ensures that the electrical contact remains firmly in contact with the rotor shaft or the mating electrical contact, thereby ensuring stable charge conduction.

[0018] The guide tube preferably includes a first axial section and a second axial section, wherein the radially outer contour of the first axial section matches the radially inner shape of the tensioning member, and the radially outer contour of the second axial section matches the radially inner shape of the inner cavity of the electrical contact. The guide tubes can be axially identical or axially different in configuration. Preferably, the radially outer portion of the guide tube is axially uniformly cylindrical to facilitate manufacturing and reduce costs.

[0019] In some preferred embodiments, the housing includes an end cap at an axial end, the end cap having a receiving hole for accommodating the first conductive member, and the first conductive member is fixedly mounted in the receiving hole. In this case, the decoupling device, or a portion thereof, can be integrated into the end cap to form a preassembled assembly. During motor assembly, the decoupling device can be installed simultaneously with the end cap.

[0020] Here, preferably, the first conductive member is configured as a circular disk made of conductive metal. Preferably, the first conductive member is configured as a circular disk made of copper. This can provide sufficient support and conductive functions and has low cost.

[0021] Here, preferably, the lead-out device further includes a bolt, and the housing, in particular the receiving hole of the end cap, is configured as a stepped hole having an internal threaded portion. The bolt is secured to the internal threaded portion and presses the first conductive member against the step of the stepped hole. In other embodiments, the first conductive member can also be secured to the housing, in particular the end cap, via another connecting member, or the first conductive member can also be secured to the housing, in particular the end cap, via a material connection method such as form fit or welding.

[0022] In some preferred embodiments, the derivation device further includes a second conductive member disposed radially inwardly of the guide tube, electrically connecting the first conductive member to the electrical contact. Preferably, the second conductive member is configured as a cable. Disposing the second conductive member radially inwardly of the guide tube allows full utilization of the space radially within the guide tube.

[0023] Here, preferably, since the support portion of the electrical contact piece supported on the radially outside of the guide tube does not participate in the discharge of charges, it has a lower precious metal doping concentration than other parts, especially the conductive parts that participate in the discharge of charges, thereby reducing the cost of the discharge device.

[0024] In some preferred embodiments, the electrical contact has a contact portion for sliding contact with the rotor shaft or with a mating electrical contact.

[0025] Here, the contact portion is preferably configured as a smooth convex surface.

[0026] Alternatively or additionally, the contact portion may have a higher hardness and / or a lower precious metal doping concentration compared to other portions of the electrical contact, particularly portions in non-sliding contact. The contact portion may have a higher hardness compared to other portions of the electrical contact, particularly portions in non-sliding contact, thereby reducing or slowing down wear when the contact portion is in sliding contact with the rotor shaft or a mating electrical contact. The contact portion may have a lower precious metal doping concentration, such as silver ion doping concentration, compared to other portions of the electrical contact, particularly portions in non-sliding contact. This reduces the cost of the wear area while maintaining electrical conductivity.

[0027] According to another aspect of the present disclosure, the aforementioned objective is achieved by an electric motor. The motor comprises: a housing; a stator and a rotor, wherein the stator is fixed relative to the housing, and the rotor is rotatable relative to the housing and the stator and has a rotor shaft; and a charge removal device constructed in the aforementioned embodiment. The motor provided herein can remove charge from the rotor shaft via the charge removal device, thereby protecting components such as bearings from pitting corrosion. The charge removal device also has an optimized structure and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Features, advantages, and technical effects of exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0029] FIG1 is a partial cross-sectional view of a motor in a lead-out device region according to an embodiment of the present disclosure.

[0030] FIG. 2 is a perspective view of a first conductive member of the guide device according to the embodiment of FIG. 1 . DETAILED DESCRIPTION

[0031] FIG1 is a partial cross-sectional view of a motor in a lead-out device region according to an embodiment of the present disclosure.

[0032] The motor according to this embodiment can be used, in particular, as a drive motor for driving electric vehicles or hybrid vehicles. The motor is constructed as an inner rotor radial motor. The motor includes a housing, a stator, and a rotor. The housing forms a storage space for accommodating the stator and rotor. The stator can be fixedly arranged in this storage space relative to the housing. The rotor can be arranged radially inwardly of the sleeve-shaped stator and can rotate relative to the housing and the stator. The output torque of the rotor is output via a rotor shaft 8, which can be supported on the housing via rolling bearings 10. In this embodiment, the metal housing includes a metal end cap 6, which is configured with a receiving hole that partially accommodates the output device. Here, the output device or a part of the output device can be integrated into the end cap 6 to form a preassembled component. When assembling the motor, the output device can be installed at the same time as the end cap 6.

[0033] According to this embodiment, the lead-out device includes: a first conductive member 1 , a guide tube 3 , an electrical contact 5 , a second conductive member 4 , a tensioning member 2 and a mating electrical contact 7 .

[0034] FIG2 shows a perspective view of the first conductive member 1. The first conductive member 1 is made of a conductive metal. In this embodiment, referring to FIG1 and FIG2 , the first conductive member 1 is constructed as a circular disk made of a conductive metal, preferably a circular disk made of copper. The first conductive member 1 is fixedly arranged at the housing and electrically connected to the housing. Specifically, the receiving hole of the end cover 6 is constructed as a stepped hole with an internal threaded portion. By fixing the bolt 9 at the internal threaded portion, the first conductive member 1 is pressed against the step of the stepped hole, thereby achieving mechanical and electrical connection between the first conductive member 1 and the end cover 6.

[0035] As shown in Figure 1, the guide tube 3 is cylindrical in shape and is fixedly mounted to the first conductive member 1 in an axially extending manner. In this embodiment, the guide tube 3 is made of plastic to reduce the weight of the device and reduce manufacturing costs.

[0036] As shown in Figure 1, the electrical contact 5 is constructed as a block-shaped member with an axially open inner cavity. For example, the electrical contact 5 is configured as a carbon brush. The electrical contact 5 is essentially made of a carbon-metal mixture, particularly a mixture of graphite and a highly conductive metal. Preferably, the electrical contact 5 is doped with copper or silver ions. The electrical contact 5 is supported radially outside the guide tube 3 by the inner cavity. Thus, the first conductive member 1 not only serves as a conductor to achieve an electrical connection between the electrical contact 5 and the end cap 6, but also serves as a support component for the guide tube 3 and the electrical contact 5.

[0037] The second conductive member 4 is arranged radially inwardly of the guide tube 3 and electrically connects the first conductive member 1 to the electrical contact 5. Preferably, the second conductive member 4 is configured as a cable. Since the second conductive member 4 is arranged radially inwardly of the guide tube 3, the space radially inwardly of the guide tube 3 can be fully utilized.

[0038] According to this embodiment, a mating electrical contact 7 electrically connected to the rotor shaft 8 is fixedly disposed on the rotor shaft 8. In this embodiment, the mating electrical contact 7 is configured as a disk made of a conductive metal. The electrical contact 5 and the mating electrical contact 7 form a slidable electrical contact relative to each other, thereby enabling the discharge device to direct the charge on the rotor shaft 8 to the end cap 6. Of course, in other embodiments, the electrical contact 5 and the rotor shaft 8 may also form a slidable electrical contact relative to each other, thereby enabling the discharge device to direct the charge on the rotor shaft 8 to the end cap 6.

[0039] According to this embodiment, the electrical contact 5 can be constructed in a non-homogeneous material. Specifically, on the one hand, the electrical contact 5 has a contact portion for sliding contact with the mating electrical contact 7. The contact portion has a higher hardness than the non-sliding contact portion of the electrical contact 5, thereby reducing or slowing down wear when the contact portion and the mating electrical contact 7 are in sliding contact. In addition, the contact portion has a lower precious metal doping concentration, such as silver ion doping concentration, than the non-sliding contact portion of the electrical contact 5, and only the conductivity requirements need to be met, thereby reducing the cost of the wear area while ensuring the conductivity. On the other hand, the electrical contact 5 is supported on the radial outside of the guide tube 3 by its inner cavity. Since the support portion of the electrical contact 5 supported on the radial outside of the guide tube 3 can not participate in the derivation of charges, it has a lower precious metal doping concentration than the conductive portion that participates in the derivation of charges, thereby reducing the cost of the derivation device.

[0040] The tensioning member 2 is axially tensioned between the first conductive member 1 and the electrical contact 5, ensuring that the electrical contact 5 always rests tightly against the mating electrical contact 7, thereby stably conducting electrical charge. In this embodiment, the tensioning member 2 is configured as a helical compression spring. The tensioning member 2 is sleeved within a guide tube 3, which guides the axial movement of the tensioning member 2 and the electrical contact 5. Referring particularly to FIG2 , the first conductive member 1 is configured with a circular base portion that matches the shape of the tensioning member 2. The axial end surface of the electrical contact 5 facing the first conductive member 1 serves as an abutment for the tensioning member 2.

[0041] In this embodiment, the radially outer portion of the guide tube 3 is configured as a uniform cylindrical shape in the axial direction to facilitate manufacturing and reduce costs. In other embodiments, the first and second axial sections of the guide tube 3 can be configured differently based on the different structures within the tensioning member 2 and the electrical contact 5. The first axial section supports and guides the tensioning member 2, and its radially outer contour matches the shape of the radially inner portion of the tensioning member 2. The second axial section supports and guides the electrical contact 5, and its radially outer contour matches the shape of the radially inner portion of the electrical contact 5.

[0042] Obviously, the above embodiments of the present disclosure are merely examples for the purpose of clearly illustrating the present disclosure, and are not intended to limit the implementation methods of the present disclosure. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present disclosure should be included in the scope of protection of the claims of the present disclosure. In the description of the present disclosure, it should be noted that the terms "first", "second" and other ordinal numbers are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0043] Reference Signs List

[0044] 1. First conductive element

[0045] 2 tensioning members, helical compression springs

[0046] 3 Guide tube

[0047] 4 Second conductive member, cable

[0048] 5 Electrical contacts, carbon brushes

[0049] 6 End caps

[0050] 7 Mating electrical contacts

[0051] 8 Motor shaft

[0052] 9 bolts

[0053] 10 bearings

Claims

1. A derivation device for a motor, The motor comprises a housing and a rotor, wherein: The rotor is rotatable relative to the housing and has a rotor shaft (8). The derivation device electrically connects the rotor shaft (8) and the housing, It is characterized in that The derivation device comprises: A first conductive member (1) is fixedly disposed on the housing and electrically connected to the housing; A guide tube (3) extending in the axial direction and fixedly arranged at the first conductive member (1); An electrical contact (5) is constructed with an inner cavity open in the axial direction, wherein the electrical contact (5) is supported radially outside the guide tube (3) by means of the inner cavity and is electrically connected to the first conductive member (1), wherein: The electrical contact (5) and the rotor shaft (8) form an electrical contact capable of sliding relative to each other, so that the derivation device can guide the charge at the rotor shaft (8) to the housing, or, A mating electrical contact (7) electrically connected to the rotor shaft (8) is fixedly provided on the rotor shaft (8), and the electrical contact (5) and the mating electrical contact (7) form electrical contact that can slide relative to each other, so that the derivation device can guide the charge on the rotor shaft (8) to the housing.

2. The derivation device according to claim 1, wherein: The guide device further comprises a tensioning member (2), wherein the tensioning member (2) is sleeved on the guide tube (3), and the tensioning member (2) is tensioned axially between the first conductive member (1) and the electrical contact member (5).

3. The derivation device according to claim 2, wherein: The guide tube (3) includes a first axial section and a second axial section, wherein the radial outer contour of the first axial section matches the radial inner shape of the tensioning member (2), and the radial outer contour of the second axial section matches the radial inner shape of the inner cavity of the electrical contact (5).

4. The derivation device according to claim 1, wherein: The housing comprises an end cover (6) on an axial end side, the end cover (6) having a receiving hole for receiving the first conductive member (1), and the first conductive member (1) is fixedly arranged at the receiving hole.

5. The derivation device according to claim 4, wherein: The first conductive member (1) is constructed as a circular disk made of conductive metal.

6. The derivation device according to claim 5, wherein: The guide device further comprises a bolt (9), the receiving hole is constructed as a stepped hole with an internal thread portion, the bolt (9) is fixed at the internal thread portion and presses the first conductive member (1) against the step of the stepped hole.

7. The derivation device according to claim 1, wherein: The guide device further comprises a second conductive member (4), which is arranged radially inside the guide tube (3) and electrically connects the first conductive member (1) with the electrical contact member (5).

8. The derivation device according to claim 7, wherein: The supporting portion of the electrical contact (5) supported radially outside the guide tube (3) has a lower noble metal doping concentration than the conductive portion.

9. The derivation device according to claim 1, wherein: The electrical contact (5) has a contact portion for sliding contact with the rotor shaft (8) or with the mating electrical contact (7), wherein: The contact portion is configured as a smooth convex surface, and / or, The contact portion has a higher hardness and / or a lower noble metal doping concentration than a non-sliding contact portion of the electrical contact (5).

10. A motor comprising: case; A stator and a rotor, wherein the stator can be fixedly arranged relative to the housing, and the rotor can rotate relative to the housing and the stator and has a rotor shaft (8); as well as A derivation device according to any one of claims 1 to 9.

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