CN114172325A

CN114172325A - Motor and automobile

Info

Publication number: CN114172325A
Application number: CN202111510668.7A
Authority: CN
Inventors: 朱殿烨; 阮鸥; 蓝晓东; 徐浩杰; 林汝裕
Original assignee: Zhejiang Geely Holding Group Co Ltd; Weirui Electric Automobile Technology Ningbo Co Ltd; Zeekr Automobile Ningbo Hangzhou Bay New Area Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Weirui Electric Automobile Technology Ningbo Co Ltd; Zeekr Automobile Ningbo Hangzhou Bay New Area Co Ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-03-11

Abstract

The application provides a motor and car, wherein, the motor includes: a housing; the output shaft penetrates through the shell and can rotate relative to the shell; the first conductive piece is fixed at one axial end of the output shaft and is coaxially arranged with the output shaft; and the second conductive piece is fixed on the shell, and the second conductive piece is opposite to the axial end surface of the first conductive piece and is in electric contact connection with the axial end surface of the first conductive piece. The automobile comprises a body and the motor, wherein the motor is arranged on the body. The application provides a motor and car do benefit to the friction loss who reduces first electrically conductive piece, do benefit to the derivation of axle current, more do benefit to the life who improves the motor.

Description

Motor and automobile

Technical Field

The application relates to the technical field of automobiles, in particular to a motor and an automobile.

Background

The new energy automobile adopts unconventional automobile fuel as a power source (or adopts conventional automobile fuel and a novel vehicle-mounted power device), integrates advanced technologies in the aspects of power control and driving of the automobile, and forms an automobile with advanced technical principle, new technology and new structure.

In the related art, the motor may include a housing, a bearing mounted to the housing, and an output shaft penetrating the bearing. Wherein the output shaft is rotatable relative to the housing via the bearing.

However, during operation of the motor, there may be a potential difference across the output shaft or between the output shaft and the housing, i.e., a shaft voltage, which, when passing through some conduction path, generates a shaft current. This shaft current, when flowing through the bearing, can cause galvanic corrosion to the bearing.

Disclosure of Invention

The embodiment of the application provides a motor and an automobile, and is used for solving the problem that the service life of the motor is seriously influenced because the shaft current flowing through the bearing of an output shaft can generate electric corrosion on the bearing.

In order to achieve the purpose, the application provides the following technical scheme:

one aspect of an embodiment of the present application provides an electric machine, including: a housing; the output shaft penetrates through the shell and can rotate relative to the shell; the first conductive piece is fixed at one axial end of the output shaft and is coaxially arranged with the output shaft; and the second conductive piece is fixed on the shell, and the second conductive piece is opposite to the axial end surface of the first conductive piece and is in electric contact connection with the axial end surface of the first conductive piece.

In one possible implementation manner, at least a part of the first conductive member has elastic deformation along the axial direction of the output shaft, so that the first conductive member abuts against the second conductive member.

In one possible implementation manner, the first conductive member includes: a housing secured to the output shaft, the housing having an open end and a closed end; the conductive column penetrates through the shell and slides in the shell along the axial direction of the output shaft; and the elastic piece is fixed between the shell and the conductive column.

In one possible implementation, the elastic member is a spring.

In one possible implementation manner, the housing includes a first portion and a second portion, and the second portion covers an open end of the first portion and encloses an accommodating space with the open end of the first portion; the first conductive piece is rotatably arranged on the first part, the second conductive piece is fixed with the second part, and the contact position of the first conductive piece and the second conductive piece is positioned in the accommodating space.

In one possible implementation manner, the second conductive member is disposed through the second portion and embedded in the accommodating space, and the second conductive member is in threaded connection with the second portion.

In one possible implementation manner, the output shaft has a central hole, and the first conductive piece is accommodated in the central hole; a sealing element is fixed at one end of the central hole, and a through hole is formed in the middle of the sealing element; the second conductive member penetrates through the through hole and is in contact with the first conductive member.

In one possible implementation manner, the central hole of the output shaft comprises a first section and a second section, the first section and the second section are coaxially arranged, and the diameter of the first section is larger than that of the second section; the sealing element is accommodated in the first section and clamped between the bottom surface of the second part and the bottom wall of the first section.

In one possible implementation manner, the second part has a counter bore for the second conductive member to pass through, and a sealing ring is disposed between the counter bore and the second conductive member.

Another aspect of the embodiments of the present application provides an automobile, including a body and the motor as described above, the motor being mounted to the body.

According to the motor and the automobile, the first conductive piece fixed on the output shaft is arranged, the second conductive piece fixed on the shell is arranged, and the contact surface of the second conductive piece is abutted against and electrically connected with the contact surface of the first conductive piece, so that the shaft current on the output shaft is led out through the first conductive piece, the second conductive piece and the shell in sequence, and the problem that the shaft current is transmitted to a bearing to damage the bearing in the prior art can be avoided; in addition, the first conductive piece is coaxial with the output shaft, and the axial end face of the first conductive piece is opposite to and in electric contact with the second conductive piece, so that the friction loss of the first conductive piece is reduced, the shaft current is led out, and the service life of the motor is prolonged.

In addition to the technical problems solved by the embodiments of the present application, the technical features constituting the technical solutions, and the advantages brought by the technical features of the technical solutions described above, other technical problems solved by the embodiments of the present application, other technical features included in the technical solutions, and advantages brought by the technical features will be further described in detail in the detailed description.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Fig. 1 is a cross-sectional view of an electric machine provided in an embodiment of the present application;

FIG. 2 is a partial cross-sectional view of the motor shown in FIG. 1;

fig. 3 is a schematic view of a first conductive member according to an embodiment of the present disclosure;

fig. 4 is a sectional view of the first conductive member shown in fig. 3;

fig. 5 is a perspective exploded sectional view of the motor shown in fig. 1;

fig. 6 is a schematic view of a second conductive member according to an embodiment of the present disclosure;

fig. 7 is a top view of the second conductive member shown in fig. 6.

Description of reference numerals:

1-a shell;

11-a first part; 111-a cylinder; 112-a surrounding wall;

12-a second part; 121-countersunk holes;

2-an output shaft;

21-a central hole; 211-first stage; 212-a second segment; 213-third section;

3-a first conductive member; 31-a housing; 32-a conductive post; 33-an elastic member; 34-a wire;

4-a second conductive member; 41-a stationary part; 42-a conductive portion;

5-a seal;

6-bearing.

With the above figures, there are shown specific embodiments of the present application, which will be described in more detail below. These drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the inventive concepts to those skilled in the art by reference to specific embodiments.

Detailed Description

In the related art motor, shaft current flowing through a bearing of the motor may cause electrical corrosion of the bearing, making the bearing unstable in operation, which in turn may cause the bearing to prematurely fail due to an increase in temperature. Typically manifested as wear of the bearing cage or pitting or even pitting of the bearing raceways.

There are several methods for processing the shaft current. One is as follows: insulated bearings are used, i.e. damage to the bearing by shaft current is reduced by blocking the shaft current from passing through the bearing. However, the cost of the insulated bearing is high; the second is that: the conductive bearing is adopted, namely, conductive grease is added into the bearing, so that part of the bearing has a conductive effect. However, the conductive bearing does not completely eliminate the shaft current. In the oil-cooled motor, oil easily enters the conductive bearing, so that the conductive grease is ineffective; the third step is that: and a carbon brush is adopted to lead out the shaft current and is grounded. However, the carbon brush is arranged along the radial direction of the output shaft and is located between the side wall of the output shaft and the inner wall of the shell, sliding friction can occur between the carbon brush and the output shaft or between the carbon brush and the shell of the motor, and considering that the rotating speed of the output shaft is high, the carbon brush can be quickly abraded under the high-strength sliding friction, and the derivation of shaft current is influenced.

The inventor of the application finds in practice that if the contact surface between the carbon brush and the shell of the motor is perpendicular to the axial direction of the output shaft of the motor, namely the friction force between the carbon brush and the shell of the motor is on a plane perpendicular to the rotating axis of the output shaft, the abrasion of the carbon brush can be effectively reduced, and the conduction of shaft current is facilitated.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments.

Example one

Fig. 1 is a cross-sectional view of an electric machine according to an embodiment of the present application. Referring to fig. 1, a motor provided in an embodiment of the present application may include a housing 1, an output shaft 2, a first conductive member 3, and a second conductive member 4. The output shaft 2 can be inserted into the housing 1 and can rotate relative to the housing 1. The first conductive member 3 can be fixed at one end of the output shaft 2 and can rotate along with the rotation of the output shaft 2. The second conductive member 4 can be fixed to the housing 1, the second conductive member 4 and the first conductive member 3 can rotate relatively, and the second conductive member 4 can contact with the first conductive member 3 and conduct electricity.

Arrows shown in fig. 1 indicate the flowing direction of the shaft current, and referring to fig. 1, when the motor is operated, movable components such as an output shaft 2, a first conductive member 3, etc. rotate, and stationary components such as a housing 1, a second conductive member 4, etc. remain stationary. When the motor works, the high voltage on the output shaft 2 can be conducted to the second conductive member 4 through the first conductive member 3 and can be conducted to the shell 1 through the second conductive member 4, and one end of the shell 1 is grounded. Thus, the voltage on the output shaft 2 is transmitted through the first conductive member 3 and the second conductive member 4, and the electric corrosion of the bearing 6 arranged outside the output shaft 2 can be effectively prevented.

Fig. 2 is a partial sectional view of the motor shown in fig. 1, and referring to fig. 2, alternatively, friction is generated between the conductive part 42 of the first conductive member 3 and the conductive part 42 of the second conductive member 4 due to the contact and relative rotation of the first conductive member 3 and the second conductive member 4. Graphite is used as the material of the portion of the first conductive member 3 contacting the second conductive member 4 in order to reduce friction and facilitate rotation between the first conductive member 3 and the second conductive member 4, because graphite has good conductivity and lubricity. Since graphite is easily worn, a metal material may be used as the material of the portion of the second conductive member 4 in contact with the first conductive member 3.

It is understood that as the time of rubbing the graphite against the metallic material increases, the graphite wears. The friction area and friction force of the graphite can be reduced as much as possible in order to reduce the abrasion of the graphite. Referring to fig. 2, the first conductive member 3 is coaxial with the output shaft 2, and the first conductive member 3 is opposite to the second conductive member 4.

Specifically, the output shaft 2 is rotatable about its axial direction when the motor is operated. The first conductive member 3 can rotate around the axis of the output shaft 2 along with the rotation of the output shaft 2. Since the first conductive member 3 is coaxial with the output shaft 2, the first conductive member 3 can rotate about its own axis. The contact surface of the first conductive member 3 may be an axial end surface of the first conductive member 3 (the leftmost end surface of the first conductive member 3 in fig. 2). The contact surface of the second conductive member 4 (the rightmost end surface of the second conductive member 4 in fig. 2) is opposed to and in contact with the contact surface of the first conductive member 3.

In the working process of the motor, the contact surface between the first conductive piece 3 and the second conductive piece 4 is perpendicular to the axial direction of the output shaft 2 of the motor, relative sliding in the related technology cannot occur between the contact surface of the first conductive piece 3 and the contact surface of the second conductive piece 4, but the contact surface of the first conductive piece 3 rotates relative to the contact surface of the second conductive piece 4, so that friction between the first conductive piece 3 and the second conductive piece 4 is reduced, the friction loss of the first conductive piece 3 is reduced, the derivation of shaft current is facilitated, and the service life of the motor is prolonged.

It should be noted that, although the wear of the first conductive member 3 can be reduced by adopting the above structure, the axial direction of the first conductive member 3 becomes short after the first conductive member 3 is used for a long time. In order to compensate for the axial length and the axial assembly error of the first conductive member 3, at least a part of the first conductive member 3 may have elastic deformation along the axial direction of the output shaft 2, so that the first conductive member 3 may abut against the second conductive member 4, and further the first conductive member 3 is always in contact with the second conductive member 4, so as to prolong the service life of the first conductive member 3 and avoid frequent replacement of the first conductive member 3.

Fig. 3 is a schematic view of a first conductive member 3 according to an embodiment of the present disclosure, and fig. 4 is a cross-sectional view of the first conductive member 3 shown in fig. 3. Referring to fig. 2 to 4, the first conductive member 3 may include a housing 31, a conductive pillar 32, and an elastic member 33. The housing 31 may have an open end and a closed end, and the housing 31 may be coaxial with the output shaft 2. The conductive post 32 may be disposed through the housing 31. At least part of the conductive pillar 32 can penetrate through the opening end of the housing 31 and abut against the second conductive member 4, and at least part of the conductive pillar 32 can slide in the housing 31. That is, the housing 31 may be disposed at least partially outside the conductive pillar 32 and may limit the conductive pillar 32 from sliding along the axial direction of the output shaft 2. The elastic member 33 may be fixed between the bottom wall of the housing 31 (the rightmost inner surface of the housing 31 shown in fig. 2) and the bottom surface of the conductive post 32 (the rightmost outer surface of the conductive post 32 shown in fig. 2). Specifically, the conductive pillar 32 may be made of graphite, the axial direction of the conductive pillar 32 may become shorter as the usage time of the conductive pillar 32 increases, and the elastic member 33 may gradually recover to elastically deform in the process of gradually shortening the conductive pillar 32, so that the conductive pillar 32 abuts against the second conductive member 4. The elastic member 33 may be a spring, an elastic sheet, rubber, or other material having elastic deformation.

Referring to fig. 4, it should be noted that, in order to make the conductive post 32 conduct the high voltage on the output shaft 2, a conductive wire 34 may be connected to the conductive post 32, and the conductive post 32 may be electrically connected to the output shaft 2 through the conductive wire 34. When the housing 31 is made of a conductive material, the housing 31 can be fixed to the output shaft 2, and the conductive pillar 32 and the housing 31 can be connected by a conductive wire 34.

With continued reference to fig. 2, in order to prevent carbon powder generated at the contact position of the first conductive member 3 and the second conductive member 4 from flying out, the sealing member 5 can be used for sealing. Fig. 5 is a perspective exploded sectional view of the motor shown in fig. 1. Referring to fig. 2 and 5, the output shaft 2 may optionally have a central hole 21, and the first conductive member 3 may be received in the central hole 21. One end of the central hole 21 may be fixed with a sealing member 5, and the middle portion of the sealing member 5 may have a through hole. The second conductive member 4 may pass through the through hole and may abut the first conductive member 3.

Specifically, the sealing member 5 may surround a receiving space with the central hole 21 of the output shaft 2. The first conductive member 3, and the portion of the first conductive member 3 contacting the second conductive member 4 may be located in the accommodating space. Carbon powder generated at the contact position of the first conductive member 3 and the second conductive member 4 can be intercepted in the accommodating space by the sealing member 5 so as to avoid flying out of the carbon powder. In addition, the sealing element 5 can also block external oil from entering the accommodating space, so as to prevent the oil from polluting the contact part of the first conductive piece 3 and the second conductive piece 4. Wherein, the sealing element 5 can be an oil seal made of one or more materials such as nitrile rubber, fluororubber, silicon rubber, acrylate rubber, polyurethane, polytetrafluoroethylene and the like.

With continued reference to fig. 2, the sealing member 5 may be fixed to the output shaft 2, and the sealing member 5 may be disposed on the outer side of the second conductive member 4 and may rotate relative to the second conductive member 4. To position and retain the seal 5 to facilitate installation and rotation of the seal 5, the central bore 21 of the output shaft 2 may include a first section 211 and a second section 212. The first section 211 may be coaxially disposed with the second section 212, and the diameter of the first section 211 may be greater than the diameter of the second section 212. The seal 5 may be housed within the first section 211 and may be sandwiched between the housing 1 and the bottom wall of the first section 211. The contact surface between the first conductor 3 and the second conductor 4 may be located within the second section 212.

Alternatively, in order to facilitate the formation of a sealed space, and also for the mounting of the first conductive member 3 with the second conductive member 4, the housing 1 may comprise a first portion 11 and a second portion 12. Referring to fig. 5, the first portion 11 may include a first open end and a second open end. The second portion 12 may cover the first opening end of the first portion 11, and may surround the first opening end of the first portion 11 to form a receiving space.

Exemplarily, referring to fig. 5, the first portion 11 may include a cylinder 111 and a surrounding wall 112, the cylinder 111 may include a bottom wall and a side wall, the side wall of the cylinder 111 may be fixed with an outer circumference of the bottom wall of the cylinder 111 and may extend toward the first direction, the side wall of the cylinder 111 and the bottom wall may enclose a first space for accommodating at least part of the output shaft 2, and an end of the side wall of the cylinder 111 facing away from the bottom wall of the cylinder 111 may form a second open end of the first portion 11. The surrounding wall 112 may be fixed to the bottom wall of the barrel 111 and may extend towards the second direction, the surrounding wall 112 and the bottom wall of the barrel 111 may also surround a second space for accommodating part of the output shaft 2, and an end of the surrounding wall 112 facing away from the barrel 111 may form a first open end of the first part 11. The second portion 12 may be a cover plate, which may cover the outside of the surrounding wall 112 to enclose the second space. That is, referring to fig. 2 and 5, the surrounding wall 112, the bottom wall of the barrel 111, and the cover plate may surround a closed accommodating space. Part of the output shaft 2 can be located in the accommodating space, and a first conductive member 3 can be fixed at one axial end of the output shaft 2 located in the accommodating space, so that the first conductive member 3 can be rotatably arranged in the accommodating space. The second conductive member 4 is fixed to the second portion 12, and at least a portion of the second conductive member 4 can be accommodated in the accommodating space. Therefore, the contact position of the first conductive piece 3 and the second conductive piece 4 can be positioned in the accommodating space, so that carbon powder generated by friction between the first conductive piece 3 and the second conductive piece 4 is prevented from flying out, and oil of the motor is prevented from entering the accommodating space.

It should be noted that, as shown in fig. 2, the second conductive member 4 may be disposed through the second portion 12, that is, a part of the second conductive member 4 is located outside the accommodating space, and a part of the second conductive member 4 is located inside the accommodating space. Of course, the second conductive member 4 may also be fixed on one side of the second portion 12, that is, the second conductive member 4 is entirely accommodated in the accommodating space.

The following describes the assembly process of the first conductive member 3 and the second conductive member 4 by taking the structure of the second conductive member 4 shown in fig. 2 and 5 as an example. Referring to fig. 2 and 5, when the first conductive member 3 and the second conductive member 4 are installed, the first conductive member 3 may be installed at one axial end of the output shaft 2, one end of the output shaft 2 may be installed in the second space, and the second space may be covered by the second portion 12. The second conductive member 4 is extended out of the second portion 12 and into the accommodating space, so that the second conductive member 4 in the accommodating space is opposite to and contacts the first conductive member 3. Thus, the contact position of the first conductive member 3 and the second conductive member 4 is located in the accommodating space.

Referring to fig. 2, the above-mentioned seal 5 may be sandwiched between the bottom surface of the second portion 12 and the bottom surface of the first section 211 of the central hole 21 of the output shaft 2 to facilitate the positioning of the seal 5 in the axial direction of the output shaft 2. In addition, the first and second substrates are,

during the penetration of the second electrically conductive member 4 into the second portion 12, the position of the second electrically conductive member 4 relative to the second portion 12 is determined to facilitate the positioning of the second electrically conductive member 4. Further, referring to fig. 2 and 5, to facilitate the above-mentioned mounting of the housing 31, the central bore 21 of the output shaft 2 may further include a third section 213, the third section 213 may be disposed coaxially with the second end, and the third section 213 may have a diameter smaller than that of the second section 212. Part of the housing 31 of the first conducting member 3 mentioned above may be embedded in the third segment 213 to facilitate the positioning and installation of the first conducting member 3. The housing 31 of the first conducting member 3 may pass through the third segment 213: and fixing in the modes of interference fit, welding, bonding and the like.

Fig. 6 is a schematic diagram of a second conductive member 4 according to an embodiment of the present disclosure, and fig. 7 is a top view of the second conductive member 4 shown in fig. 6. Referring to fig. 2, 6 and 7, in order to facilitate the positioning of the second conductive member 4 on the second portion 12, the second conductive member 4 may optionally include a fixed portion 41 and a conductive portion 42, the fixed portion 41 may be disposed coaxially with the conductive portion 42, and the diameter of the fixed portion 41 may be larger than that of the conductive portion 42.

Referring to fig. 2 and 5, the second portion 12 may have a counter bore 121. The counterbore 121 may include a threaded section as well as a small diameter section. The threaded section may be coaxial with the minor diameter section, and the threaded section may have a diameter greater than the diameter of the minor diameter section. When the second conductive member 4 is inserted into the second portion 12 as shown in fig. 2, the fixing portion 41 of the second conductive member 4 can be in threaded connection with the threaded portion, and the conductive portion can be inserted into the small diameter portion and extend into the accommodating space, and contact with the first conductive member 3.

In addition, in order to achieve sealing at the counterbore 121, optionally, a sealing ring may be provided between the fixing portion 41 of the second conductive member 4 and the bottom surface of the threaded section. In addition, in order to facilitate the user to screw in the fixing portion of the second conductive member, referring to fig. 7, the fixing portion may have a hexagon socket inside.

In summary, the motor provided by the embodiment of the present application can have the following advantages:

the smooth conduction of shaft current is ensured, oil is prevented from entering and reducing the conductive effect, and the voltage of an output shaft of the motor is effectively reduced; the friction loss of the first conductive piece is effectively reduced, and the generation amount of carbon powder is reduced; effectively preventing carbon powder from entering oil to cause pollution and motor short circuit; the first conductive piece and the second conductive piece are simple in structure, convenient to assemble, low in cost, strong in maintainability and high in reliability. In addition, the motor that this application provided can be for oil-cooled motor, can be water-cooled motor again, and the motor that this application provided can fully reduce the axle voltage, and is with low costs, and the assembly is easy, and the reliability is high, greatly reduced's the risk of bearing overcurrent, improved bearing life.

Example two

An automobile comprises a body and the motor provided by the embodiment, wherein the motor can be arranged on the body.

The terms "upper" and "lower" are used for describing relative positions of the structures in the drawings, and are not used for limiting the scope of the present application, and the relative relationship between the structures may be changed or adjusted without substantial technical changes.

It should be noted that: in this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In addition, in the present application, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integral to; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electric machine, comprising:

a housing (1);

the output shaft (2) penetrates through the shell (1) and can rotate relative to the shell (1);

the first conductive piece (3) is fixed at one axial end of the output shaft (2) and is coaxially arranged with the output shaft (2);

and the second conductive piece (4) is fixed on the shell (1), and the second conductive piece (4) is opposite to the axial end surface of the first conductive piece (3) and is in electric contact connection with the axial end surface of the first conductive piece.

2. The machine according to claim 1, characterized in that at least part of the first conducting member (3) has an elastic deformation in the axial direction of the output shaft (2) so that the first conducting member (3) abuts against the second conducting member (4).

3. The machine according to claim 2, characterized in that said first conducting member (3) comprises:

a housing (31) fixed to the output shaft (2), the housing (31) having an open end and a closed end;

the conductive column (32) penetrates through the shell (31) and slides in the shell (31) along the axial direction of the output shaft (2);

and the elastic piece (33) is fixed between the shell (31) and the conductive column (32).

4. A machine as claimed in claim 3, characterized in that said elastic member (33) is a spring.

5. The machine according to any of the claims 1-4, wherein the housing (1) comprises a first part (11) and a second part (12), the second part (12) is covered at the open end of the first part (11) and encloses a receiving space with the open end of the first part (11);

the first conductive piece (3) is rotatably arranged on the first part (11), the second conductive piece (4) is fixed with the second part (12), and the contact position of the first conductive piece (3) and the second conductive piece (4) is positioned in the accommodating space.

6. The electric machine according to claim 5, characterized in that the second conductive member (4) is inserted through the second portion (12) and embedded in the receiving space, and the second conductive member (4) is in threaded connection with the second portion (12).

7. The machine according to claim 5, characterized in that said output shaft (2) has a central hole (21), said first electrically conductive member (3) being housed inside said central hole (21);

a sealing element (5) is fixed at one end of the central hole (21), and a through hole is formed in the middle of the sealing element (5);

the second conductive member (4) passes through the through hole and contacts the first conductive member (3).

8. An electric machine according to claim 7, characterized in that the central bore (21) of the output shaft (2) comprises a first section (211) and a second section (212), the first section (211) being arranged coaxially with the second section (212), and the first section (211) having a larger diameter than the second section (212);

the seal (5) is housed inside the first section (211) and is interposed between the bottom surface of the second portion (12) and the bottom wall of the first section (211).

9. An electric machine according to claim 5, characterized in that the second part (12) has a counter bore (121) for the passage of the second conductor (4), a sealing ring being provided between the counter bore (121) and the second conductor (4).

10. An automobile comprising a body and an electric machine as claimed in any one of claims 1 to 9 mounted to the body.