阅读说明：本技术 用于旋转电机的电刷架 (Brush holder for rotating electrical machine ) 是由 R.莫蒂尔 R.本欧姆兰 C.蒙泰尔 C.路易斯 L.多曼格 F.谢特尔 F.格林 于 2018-06-04 设计创作，主要内容包括：本发明涉及一种旋转电机,特别用于机动车辆。该电机包括：有源部件；外壳(11)；电刷架(24),包括：至少一个电刷(23)、所述电刷的励磁迹线(44)和由电绝缘材料形成的壳体(37)、用于将电刷架(24)安装在所述电机中的固定装置(49)；以及电子组件(36),其包括控制模块(61)和将电刷架的励磁迹线(44)连接到所述控制模块的励磁迹线(48)。电子组件(36)包括接地迹线(63),所述接地迹线通过固定装置(49)电连接至控制模块(61)和外壳(11)。(The present invention relates to a rotating electrical machine, in particular for a motor vehicle. The motor includes: an active component; a housing (11); a brush holder (24) comprising: at least one brush (23), an excitation track (44) of the brush and a housing (37) formed of an electrically insulating material, a fixing device (49) for mounting a brush holder (24) in the electrical machine; and an electronic assembly (36) including a control module (61) and an excitation trace (48) connecting an excitation trace (44) of a brush holder to the control module. The electronic assembly (36) includes a ground trace (63) that is electrically connected to the control module (61) and the housing (11) by a fixture (49).)

1. A rotating electric machine, in particular for a motor vehicle, the electric machine (10) comprising:

-an active component, in particular comprising a rotor (12) and a stator (15);

-a housing (11) surrounding the active component;

-a brush holder (24) comprising:

-at least one brush (23) allowing the supply of electricity to one of the active components;

-at least one bus bar (44) for the electrical excitation of the brushes;

-a housing (37) formed of an electrically insulating material, which surrounds at least a portion of the excitation bus bar (44) and comprises a housing portion (39) that at least partially houses the brush (23);

-a fixing device (49) enabling the assembly of a brush holder (24) in the electric machine; and

-an electronic assembly (36) comprising a control module (61) designed to control the electric machine and an excitation bus bar (48) connecting an excitation bus bar (44) of a brush holder to the control module;

characterized in that the electronic assembly (36) comprises a ground bus bar (63) electrically connected to the control module (61) and to the casing (11) by means of a fixing device (49).

2. An electric machine as claimed in claim 1, characterized in that the brush holder (24) is fitted to the housing (11) by fixing means (49) which allow electrical connection between the ground bars (63) of the electronic components (36) and the housing.

3. The machine according to claim 2, characterized in that the fixing means (49) are screwing means, in particular screws or tie rods.

4. A machine as claimed in claim 2 or 3, characterized in that the housing (11) comprises at least one bearing (17) and one stud (42) extending protrudingly from a flange of the bearing, wherein the stud (42) comprises an opening allowing passage of a fixing means (49) and a tapped portion cooperating with a threaded portion of the fixing means.

5. The machine according to any of claims 2 to 4, characterized in that the ground busbar (63) of the electronic assembly comprises a first portion (65) for connection with a fixing device (49) and a second portion (66) for connection with a control module (61).

6. An electric machine according to claim 5, characterized in that the first connection portion (65) of the ground busbar (63) has the form of a ring.

7. The machine according to claim 5 or 6, characterized in that the fixing means (49) comprise a head (71) and a body (72) extending from the head, and in that the head (71) is in electrical contact with the first connection portion (65) of the ground bar (63).

8. The electrical machine according to any one of claims 5 to 7, characterized in that the first connection portion (65) of the ground busbar (63) extends on a radial plane different from the radial plane on which the first connection portion (68) of the excitation busbar (48) of the electronic assembly (36) extends, wherein the first portion (68) of the excitation busbar is designed to be in electrical contact with the excitation busbar (44) of the brush holder (24).

9. The electrical machine according to claim 8, characterized in that the first connection portions (65) of the ground bars (63) and the first connection portions (68) of the field bars (48) are axially separated from each other by a clamping member (50) formed of an electrically insulating material.

10. The machine according to claim 9, characterised in that the clamping member (50) comprises a clamping device (73) which makes it possible to fix the clamping member on the excitation bus bar (48) and/or on the ground bus bar (63) of the electronic assembly (36).

11. An electric machine according to any one of claims 2 to 10, characterized in that the electrical contact between the excitation bus bars (44) of the brush holder (24) and the excitation bus bars (48) of the electronic component (36) is provided by means of the fixing device (49).

12. The electric machine according to any of claims 2 to 11, characterized in that the brush holder and the electronic assembly are different from each other.

Technical Field

The present invention relates to a brush holder for a rotating electrical machine.

Background

The invention has particularly advantageous application in the field of rotating electrical machines, such as alternators, alternator starters or reversible electrical machines. It should be remembered that a reversible electric machine is a rotary electric machine that can work reversibly, first as a generator functioning as an alternator and then as an electric motor, for example in order to start the heat engine of a motor vehicle.

The rotating electric machine includes a rotor that is rotationally movable about an axis and a fixed stator that surrounds the rotor. The rotor, stator and shaft are mounted in a housing that also supports electronic components that control the operation of the motor. In alternator mode, as the rotor rotates, it induces a magnetic field on the stator, which is then converted into an electric current to power the vehicle electronics and charge the battery. In the motor mode, the stator is energized and induces a magnetic field that rotates the rotor.

In the reduction of gases, especially CO ₂In the context of emissions and vehicle mixing, new functions have been developed. These new functions are, for example, stopping the engine when the vehicle is stopped, regenerative braking, and traction in the low-speed electric mode. These functions are provided by the rotating electrical machine and therefore it must be more powerful. For this purpose, the rotating electric machine is based on an electric network commonly used throughout the vehicleDifferent grids operate. Indeed, a conventional grid accepting a maximum voltage of about 16V requires too high a current level for the power required to integrate all new functions and the conventional functions of the alternator (such as supplying the battery and to the consumers) at the same time. Conventional power grids are no longer suitable to exceed a certain power level required in order to properly ensure these new functions.

The integration of these two electrical networks inside the vehicle means that the rotating electrical machine must be able to control these different voltages. The two power grids have the same ground potential, called chassis ground, which is connected in particular to the vehicle body. The electric machine is excited by a second electrical network having a voltage level that is higher than the voltage level of the first electrical network that is normally used on board the vehicle. The control of the electric machine by means of the electric machine control is performed by means of the first power network. The electronic components of the motor are thus connected to two electrical networks.

The first electrical network may also ground the electronic components of the electric machine. However, the path that makes it possible to connect ground to the electronic component is not direct and may be longer or shorter and is therefore inductive depending on the arrangement of the vehicle. This can lead to an offset between the chassis ground and the ground of the electronic components, in particular due to a voltage drop in the supply circuit of the motor. This type of offset causes problems with electromagnetic compatibility with the motor environment.

Disclosure of Invention

The object of the present invention is to reduce the drawbacks of the prior art and in particular to avoid problems of electromagnetic compatibility.

To this end, the subject of the invention is therefore a rotating electrical machine, in particular for motor vehicles. According to the invention, the electric machine comprises an active part, which in particular comprises a rotor and a stator, with a housing surrounding the active part. This motor still includes the brush yoke, and this brush yoke includes: at least one brush allowing the supply of electricity to one of the active components; at least one bus bar for electrical excitation of the brushes; and a housing formed of an electrically insulating material, the housing surrounding at least a portion of the field bus bar and including an accommodating portion that at least partially accommodates the brush. In addition, the motor comprises fixing means which make it possible to fit the brush holder in the motor; and an electronic assembly comprising a control module designed to control the electric machine and an excitation bus bar connecting the excitation bus bar of the brush holder to the control module. Again according to the invention, the electronic assembly comprises a ground bus bar electrically connected to the control module and to the housing by means of fixing means.

Owing to the invention, the control module is directly connected to ground potential. This may improve the electromagnetic compatibility of the motor with the motor environment. Therefore, the motor can be better protected from external interference and cannot cause interference to the external environment.

The ground bus bar is electrically connected to the control module and the housing by the fixing means that there is no direct contact between the housing and the ground bus bar. Thus, the fixing means is inserted on the electrical path between the ground bus bar and the housing.

According to an embodiment, the housing is at ground potential.

According to an embodiment, the control module is connected to a first electrical network via the motor control module and to a second electrical network for energizing the motor.

According to one embodiment, the brush holder is mounted on the housing by means of fixing means which allow an electrical connection between the ground bus bar of the electronic assembly and the casing.

This type of device makes it possible to transmit the electricity of the first electrical network to the electronic components in a simple and inexpensive manner, and also to fit the brush holder on the housing. This also makes it possible to avoid long wired connections to bring the chassis to the control module, thus avoiding having to have an inductive path. In addition, a single device thus has two functions, so that the size of the motor can be reduced.

According to an embodiment, the fixing means is formed of an electrically conductive material.

According to one embodiment, the fixing means is a tightening means, in particular a screw or a tie rod.

For example, the housing of the electronic assembly, the housing of the brush holder, and the housing each include openings that allow the passage of the securing device. This makes it possible to mechanically connect the components together. In this case, the respective openings in the electronic component, the brush holder and the housing are arranged facing each other.

According to an embodiment, the housing comprises at least one bearing and one stud extending protrudingly from a flange of the bearing, the stud comprising an opening allowing passage of the fixing means and a tapping portion cooperating with the threaded portion of the fixing means. This makes it possible to improve the reliability of the electrical connection between the housing and the ground bus bar of the electronic component.

According to one embodiment, the electronic component is mounted on the housing by means of a fixing device.

According to an embodiment, the housing further comprises a front bearing and a rear bearing, wherein the brush holder and the electronic assembly are mounted on said rear bearing.

According to an embodiment, the ground bus bar of the electronic assembly comprises a first portion for connection with the fixture and a second portion for connection with the control module.

For example, a ground bus bar is added to the control model. According to a variant embodiment, the ground bus bar may be integrated in the control module.

According to an embodiment, the electronic assembly comprises a housing on which the control module is arranged and in which the ground bus bar and the field bus bar are at least partially overmoulded.

According to an embodiment, the first connection portion of the ground bus bar has the form of a ring. As a variant, the first connection portion of the ground busbar may have the form of a circular arc or any other form that can ensure sufficient electrical contact.

According to one embodiment, a fixation device includes a head and a body extending from the head. In this embodiment, the header is in electrical contact with the first connection portion of the ground bus bar.

According to an embodiment, the first connection portion of the ground bus bar is in direct contact with the fixture, in particular with the head of the fixture. As a variant, the first connection portion of the ground busbar can be in indirect contact with the fixing means, in particular via a washer.

According to an embodiment, the first connection portion of the ground bus bar extends on a radial plane different from the radial plane on which the first connection portion of the excitation bus bar of the electronic assembly extends, wherein said first portion of the excitation bus bar is designed to be in electrical contact with the excitation bus bar of the brush holder.

According to an embodiment, the first connection portion of the ground bus bar and the first connection portion of the field bus bar are axially separated from each other by a clamping member formed of an electrically insulating material. The clamping member makes it possible to insulate the grounding bus bar from the excitation bus bar, thereby avoiding the formation of salt bridges.

According to one embodiment, the excitation bus bar of the electronic assembly has a first portion for connection with the excitation bus bar of the brush holder and a second portion for connection with the control module.

According to one embodiment, the excitation bus bar of the brush holder has a first portion for connection with the excitation bus bar of the electronic assembly and a second portion for connection with the brush.

According to an embodiment, an electrical contact is provided between the excitation bus bar of the brush holder and the excitation bus bar of the electronic assembly by means of the fixing device.

For example, the first connecting portion of the excitation bus bar of the electronic component and the first connecting portion of the excitation bus bar of the brush holder each have the form of circular arcs that fit each other.

According to an embodiment, the clamping member is positioned to exert a pressure on the excitation bus bar of the electronic assembly. The clamping member can ensure good electrical contact between the excitation bus bar of the electronic assembly and the excitation bus bar of the brush holder.

According to one embodiment, the clamping part comprises a clamping device which makes it possible to fix the clamping part on the excitation bus bar and/or on the ground bus bar of the electronic assembly.

For example, the clamping device cooperates with a ground bus bar of the electronic assembly, in particular with a first connecting portion of said bus bar. In this case, the clamping means are formed by at least one ramp extending from the body of the clamping member.

According to an embodiment, the clamping member comprises an opening allowing passage of the fixation device.

According to one embodiment, the brush holder includes two brushes that are respectively arranged in the two accommodation portions of the housing and respectively connected to the two electrically excited bus bars. For example, one of the brushes is at a positive potential of the second electrical network, while the other brush is at a negative or ground potential of the second electrical network.

According to one embodiment, the rotating electric machine comprises a collector fitted on one of the active components, and the brush is in contact with a collector bar of the collector for supplying power to said active component.

According to one embodiment, the electronic assembly, in particular the control module, is designed to be able to control two different electrical networks.

According to one embodiment, the brush holder and the electronic assembly are different from each other. In other words, the brush holder and the electronic assembly form two separate elements, so that the electronic assembly is not integrated in the brush holder.

The rotating electric machine may advantageously form an alternator, an alternator-starter or a reversible electric machine.

Drawings

The invention will be better understood from a reading of the following detailed description of non-limiting embodiments thereof, and from an examination of the attached drawings, in which:

figure 1 shows schematically and partially a cross-sectional view of a rotating electric machine according to an embodiment of the invention;

figure 2 shows schematically and partially an isolated partial view of a part of the electrical machine in figure 1;

figure 3 shows schematically and partially a perspective view from above of the example of the brush holder in figure 1;

figure 4 shows schematically and partially a perspective view of the brush holder of figure 3;

fig. 5 schematically and partially shows a perspective view of an example of a portion of the electronic assembly in fig. 1;

fig. 6 schematically and partially shows a perspective view of an example of the configuration of the bus bar of the electronic assembly in fig. 5;

fig. 7 schematically and partially shows a perspective view of an example of a clamping member of the electronic assembly in fig. 5;

fig. 8 schematically and partially shows a cross-sectional view of an electronic assembly and of a fixing region of an electrical brush holder on a bearing according to the example of fig. 1; and

fig. 9 shows a simplified electrical diagram of the electric machine of fig. 1 in a vehicle.

Identical, similar or analogous elements have the same reference symbols in the various figures.

Detailed Description

The embodiments described below are in no way limiting; in particular, if such a choice of features is sufficient to provide technical advantages or to distinguish the invention from the prior art, it will be possible to envisage variants of the invention comprising only the choice of features described below, isolated from the other features described. In particular, all variants and all embodiments described can be combined with one another if no technical objection to such a combination is present. In this case, this will be referred to in the present specification.

Fig. 1 shows a compact polyphase rotary electric machine 10, in particular for a motor vehicle. The rotating machine 10 converts mechanical energy to electrical energy in an alternator mode and may operate in a motor mode to convert electrical energy to mechanical energy. The rotating electrical machine 10 is, for example, an alternator-starter or a reversible electrical machine.

The rotary electric machine 10 includes a housing 11. Inside this housing 11, the rotating electrical machine further includes a shaft 13, a rotor 12 that rotates integrally with the shaft 13, and a stator 15 that surrounds the rotor 12. The rotary motion of the rotor 12 is about the axis X.

In the following description, the terms "axial", "radial", "external" and "internal" refer to an axis X passing through the shaft 13 at its centre. The axial direction corresponds to the axis X, while the radial orientation corresponds to a plane parallel to the axis X and in particular perpendicular to the axis X. In the radial direction, the terms "outer" or "inner" should be understood with respect to the same axis X, the term "inner" corresponding to an element directed towards the axis or closer to the axis than a second element, while the term "outer" denotes spaced apart from the axis.

In this example, the housing 11 includes a front bearing 16 and a rear bearing 17 assembled together. These bearings 16, 17 have a hollow form and each centrally support a respective ball bearing 18, 19 for rotatably mounting the shaft 13.

The pulley 20 is fixed on the front end of the shaft 13 at the front bearing 16, for example by means of a nut supported on the base of the cavity of the pulley. The pulley 20 can transmit the rotary motion to the shaft 13 or cause the shaft 13 to transmit its rotary motion to a belt.

The rear end of the shaft 13 supports a current collector 22. The collector comprises a body made of an electrically insulating material and a collector ring 21 overmoulded in said body. The slip ring 21 has an annular form, and rotates together with the rotor 12. Brushes 23 belonging to a brush holder 24 are arranged to rub on the slip rings 21. The brush holder 24 is electrically connected to an electronics assembly 36 that controls the voltage applied to the brushes.

The front bearing 16 and the rear bearing 17 may also comprise substantially lateral openings for the passage of air to allow the cooling of the rotating electrical machine by the circulation of air generated by the rotation of a front fan 25 on the front axial face of the rotor 12, i.e. at the front bearing 16, and by the rotation of a rear fan 26 on the rear axial face of the rotor, i.e. at the rear bearing 17. Alternatively, the bearing will be able to comprise a conduit allowing the passage of cooling liquid.

In this example, the rotor 12 is a rotor having claws. It comprises two magnetic wheels 31. Each magnet wheel 31 is formed by a flange 32 and a plurality of claws 33 forming magnetic poles. The flange 32 has a transverse orientation and, for example, has a substantially annular form. The rotor 12 also comprises a cylindrical core 34, which is axially interposed between the magnetic wheels 31. In this case, the core 34 is formed by two half-cores, each of which belongs to one of the magnetic wheels. Between the core 34 and the claw 33, the rotor 12 comprises a coil 35, in which case the coil 35 comprises a winding hub and an electrical winding on the hub. The slip rings 21 belonging to the current collector 22 are connected to said coil 35 by means of a wired connection, for example. The rotor 12 may also comprise a magnetic element interposed between two adjacent jaws 33.

In this embodiment, the stator 15 comprises a main body 27 in the form of a set of metal plates provided with recesses, for example of the semi-closed or open type, equipped with recess insulation for fitting electrical windings 28. The windings 28 pass through notches in the body 27 and form a bun 29 and a bun 30 on either side of the stator body. The windings 28 are connected, for example, in the form of a star or a triangle.

In addition, the winding 28 is formed of one or more phases. Each phase includes at least one conductor that passes through a notch in stator body 27 and forms a bun with all phases. The windings 28 are electrically connected to the electronic assembly 36.

The electronic assembly 36 comprises a control module 61, at least one electronic power module enabling control of the phases of the winding 28 and an excitation circuit enabling control of the electric machine 10. The power modules form a current rectifier bridge in order to convert the alternating current generated by the electric machine 10 into direct current, in particular in order to supply the battery and the on-board network of the vehicle. In addition, the electronics assembly 36 includes a housing 62, which housing 62 may house the power module and/or the control module 61. The housing 62 is mounted on a heat sink that includes fins that extend out and direct the air flow to cool the various modules. According to a variant embodiment, the radiator may comprise ducts for the circulation of a cooling fluid to allow cooling of the different modules. Alternatively, the heat sink may include fins and cooling ducts.

When the electrical winding 35 is energized by the brushes 23, the rotor 12 is magnetized and becomes an inductor rotor forming north and south magnetic poles at the claws. The inductor rotor generates an induced alternating current in the induction stator as the shaft 13 rotates. The power module of the electronic assembly 36 then converts this induced alternating current into direct current, in particular in order to supply the electrical loads of the on-board network of the motor vehicle and the consumers, and to charge its battery in alternator mode.

In order to implement new functions, vehicles require a more powerful electrical network than is conventionally used. To this end, the vehicle may include two different batteries, as shown in fig. 10. The first battery 76 supplies a first electrical network normally used for motor vehicles. The second battery 77 supplies the second grid with a potential different from that of the conventional network. In particular, the second battery 77 is more powerful than the first battery 76. For example, the potential of the first electrical network varies between 0V and 12V, while the potential of the second electrical network varies between 0V and 60V, in particular between 0V and 48V. The two batteries are connected to each other by a DC/DC electronic converter 43, called direct-to-direct converter.

The excitation of the rotating electrical machine 10 is operated via the second electrical network. The power supply to the rotor coil 35 is thus provided by a second electrical network which is directly connected to the electronic components 36 of the electric machine 10, in particular to the control module 61.

The vehicle further comprises a motor control module 41 enabling control of the electric machine 10 according to the user's requirements. This module 41 transmits control signals to the electronic components 36 of the motor, in particular to the control module 61. The module 41 is operated via the first power grid. The electronic assembly 36, in particular the control module 61, is therefore designed to be able to control these two different electrical networks.

In addition, the vehicle body is connected to the same chassis ground potential 75 as that of the DC/DC converter 43. The housing 11 in contact with the vehicle body is also at chassis ground potential 75. The control module 61 is grounded through its connection to the motor control module 41. However, since the connection is made by wires that may be longer or shorter depending on the arrangement of the vehicle, the ground taken may be slightly different from the chassis ground 75. For reasons of electromagnetic compatibility, the control module 61 needs to have more direct access to the chassis ground 75. The brush holder 24 is used to bring the chassis ground 75 to the control module 61.

According to a variant embodiment, the vehicle may comprise a single battery, the power level of which is equal to the power level of the second battery 77. The transformer will be able to be used to create another grid to supply the motor control module.

As can be seen in the example of fig. 2, the brush holder 24 is fitted around the collector 22 on the rear bearing 17, the collector 22 being fitted at the rear end of the shaft 13. An electronic assembly 36 is also mounted on the rear bearing 17 and includes a receptacle into which the current collector 22 and the brush holder 24 are at least partially inserted.

The brush holder 24 includes a housing 37 made of an electrically insulating material and two brushes 23. Each brush 23 is at the potential of the second electrical network in order to supply power to the rotor coil 35 via the current collector 22. The housing 37 includes a receptacle 39 into which the two different brushes 23 are at least partially inserted. Each receptacle 39 opens into the inner radial wall of the housing so that the associated brush is in contact with the respective slip ring 21. Each brush 23 extends in a radial direction with respect to axis X and has radially opposite inner and outer faces, with the inner face being in contact with relative slip ring 21. Furthermore, the brush holder 24 comprises springs 40 arranged in the accommodation 39, as shown in fig. 1, wherein each spring is associated with a brush 23 and exerts a force on the outer face of the associated brush. Preferably, the applied force has a radial direction. Each spring 40 is in a compressed state when the brush holder 24 is assembled around the current collector 22. The force exerted by the spring on the brush makes it possible to ensure electrical contact between said brush and the slip ring, while compensating for the wear of the brush caused by the rotary motion of the ring.

The brush holder 24 further includes a protective cover 38 extending from an end of the housing 37 to which the accommodation portion 39 opens. A protective cover 38 surrounds the current collector 22 and the end of the shaft 13. The protective cover thus enables the respective electrical contact between the brush and the collector ring to be insulated from the external environment.

In the example of fig. 3, brush holder 24 comprises two excitation bus bars 44, each at a different potential, and able to supply power to brushes 23. For example, one of the brushes is at a positive potential of the second electrical network, while the other brush is at a negative or ground potential of the second electrical network. The field bus bars 44 are electrically insulated from each other by the housing 37.

The excitation bus bar 44 is formed in the same manner. Each bus bar 44 thus has a first portion 45 for connection with the electronic assembly 36, a second portion 46 for connection with the associated brush 23, and a connecting portion 47 capable of connecting the first and second connecting portions to each other. Preferably, the connecting portion 47 is completely contained in the housing 37 of the brush holder, as shown in fig. 4.

The second connection portion 46 is electrically connected to a pigtail (not shown) that is itself connected to the associated brush 23. This second connection portion is accommodated in an obvious manner in the end wall of the housing 37, so that the connection to the braid can be simplified. In particular, the second portion is located in the outer radial end wall of the housing 37. The plaits are arranged inside the respective accommodation 39 and are connected to the connection portions, for example by crimping and/or by welding. Alternatively, the second connection portion may be positioned in the receiving portion of the housing, not on the surface thereof.

The first portion 45 of the excitation bus bar 44 is accommodated in an end wall of the housing 37 in a distinct manner. The wall faces the electronic component 36; preferably, this is an axial end wall of the housing 37.

The electronic assembly 36 includes a ground bus bar 63 and two field bus bars 48.

In the example of fig. 5 and 6, the excitation bus bars 48 each have a first portion 68 for connection with a respective excitation bus bar 44 of the brush holder, a second portion 69 for connection with the control module 61, and a connecting portion 70 capable of connecting the first and second connecting portions to each other.

The ground bus bar 63 of the electronic component has a first portion 65 for connection with the housing 11 via the fixing device 49, a second portion 66 for connection with the control module 61, and a connecting portion 67 capable of connecting the first and second connecting portions to each other.

Preferably, the connecting portions 67, 70 are at least partially overmolded in the housing 62 of the electronic assembly 36. Again preferably, the first and second portions 65, 68, 66, 69 extend protrudingly on either side of the housing 62. For example, the second connecting portions 66, 69 each have the form of a connecting lug that mates with a receptacle of the control module 61.

According to a variant embodiment, not shown, the excitation bus bar 48 and the ground bus bar 63 may extend protruding directly from the control module 61.

The fastening device 49 makes it possible both to fasten the brush holder 24 to the housing 11, in particular to the rear bearing 17, and to establish an electrical connection between the ground bar 63 of the electronic component 36 and the housing 11. In the embodiment described here, the fixing device 49 is a screwing device. Said means are in particular screws or tie rods and comprise a head 71 and a body 72 projecting from the head. In addition, the fixing means is formed of a conductive material.

For example, the housing 37 of the brush holder 24 and the housing 62 of the electronic assembly 36 and the rear bearing 17 each include openings disposed facing each other to allow the main body 72 of the fixture 49 to pass through. In this case, the opening in the rear bearing 17 is formed in a stud 42 which extends protrudingly from the plate of said bearing. The body 72 of the fixture 49 includes a threaded portion that mates with the tapped portion of the stud 42.

The head 71 of the fixture is in electrical contact with the first portion 65 of the ground bus bar 63. The contact may be direct or may be formed by a gasket 60 made of a conductive material.

In the embodiment shown in fig. 6, the first connection portion 65 of the ground bus bar 63 has the form of a ring, the opening of which allows the main body 72 to pass through. The dimensions of the ring are adapted to the dimensions of the head 71 to ensure a good electrical contact. The first connection portion 65 extends in a substantially flat manner.

As shown in the example in fig. 6, the first connection portion 65 of the ground bus bar 63 extends on a different radial plane than the radial plane on which the first connection portion 68 of the excitation bus bar 48 of the electronic component 36 extends. A clamping member 50 made of an electrically insulating material axially separates the first connection portions.

In this example, the first portions 45 of the excitation bus bars 44 each have the form of a circular arc and are positioned around an opening formed in the housing 37 that allows the fixing device 49 to pass through. The two connection portions 45 of the excitation bus bar 44 are positioned symmetrically with respect to the opening.

The first portions 68 of the excitation bus bars 48 each have the form of a first portion 45 adapted to be in contact therewith. In this example, the first portions 68 each have the form of a circular arc and are positioned to form an opening that allows the fixing device 49 to pass through.

Each first connection portion 45 is preferably in direct contact with a first portion 48 of an associated excitation bus bar 48 of the electronic assembly 36. The first portions 68, 45 each extend in a substantially flat manner and face the portion they contact. For example, contact grease may be added at the electrical contacts between the excitation bus bars of the brush holder and the excitation bus bars of the electronic assembly to avoid corrosion of these bus bars.

The clamping member 50 is positioned by means of the fixing means 49 to exert pressure on the first portion 68 in order to ensure good electrical contact with the first portion 45.

The clamping member 50 includes an opening 64 for passage of the securing device 49.

During assembly of the electrical machine, the clamping member 50 is radially inserted so as to be axially disposed between the field bus bar 48 and the ground bus bar 63. The clamping member 50 comprises a clamping device 73, which clamping device 73 is capable of fixing the clamping member with the grounding bars 63 in a substantially radial direction. The clamping means 73 are formed by two inclined surfaces against which the first portion 65 of the grounding bar 63 radially abuts.

In this embodiment, the brush holder 24 comprises a portion of a cylindrical body 51 that extends axially protruding from the housing 37 to the clamping member and forms an arc that at least partially surrounds the connection between the excitation bus bars 44, 48. This portion of the cylindrical body 51 enables the connection to be electrically insulated from the external environment. The clip member 50 may include a groove 54, the groove 54 being capable of receiving the portion of the cylinder 51.

Also in the example shown in these figures, the brush holder 24 comprises a sleeve 52, which sleeve 52 extends axially projecting from the housing 37 to the clamping member 50. The sleeve is located between the fixing means 49 and the connection between the excitation bus bars 44, 48, thereby surrounding said fixing means 49. The sleeve 52 enables electrical insulation of the fixing means 49 in contact with the attached rear bearing 17.

Also in the example shown in these figures, the brush holder 24 includes a partition 53 that extends protrudingly from the housing 37 to the holding member 50. In particular, the partition 53 extends between the first two connection portions 45 of the excitation bus bar 44, so as to electrically insulate them from each other and avoid the formation of salt bridges. In this case, the brush holder comprises two partitions 53 extending on either side of the sleeve 52. The clip member 50 may include one or two cavities into which the divider 53 may be inserted.

According to a variant embodiment, not shown, a portion of a cylinder, a sleeve and a spacer can be formed on the gripping member 50. The housing 37 then comprises a recess capable of receiving the portion of the cylinder, wherein the widened diameter of the opening may receive the sleeve, and a cavity that may receive the partition.

The clip member 50 may include a collar 74 that extends protrudingly from the main body of the portion in a direction axially opposite to the brush holder 24, and so as to at least partially surround the first connection portion 65 of the ground bus bar 63. The collar preferably extends over only a portion of the body so as to allow radial insertion of said clip member. This makes it possible to protect the connection between the first connection portion 65 and the fixing device 49 from the external environment.

The housing 37 of the brush holder 24 includes a fixing portion that supports the first portion 45 of the excitation bus bar 44 and the opening 55 through which the fixing device 49 passes. In this embodiment, the fixing portion is located on the side of the housing 37, i.e., on a portion of the brush holder extending between the two radially inner and outer radial ends of the housing 37. According to a variant embodiment, the fixed portion may be positioned on the outer radial end of the housing 37.

To facilitate positioning of the brush holder 24 on the rear bearing 17, the brush holder comprises in this case a first indexing stud 58 capable of indexing the brush holder on the bearing in a first direction and a second indexing stud 59 capable of indexing the brush holder on the bearing in a second direction perpendicular to the first direction.

The invention has application in particular in the field of alternators, alternator starters or reversible machines, but it can also be applied to any type of rotating electrical machine.

It is to be understood that the above description is provided by way of example only and not as a limitation on the scope of the invention, as no deviation from the invention will be implied by the replacement of different elements by any other equivalents.