CN110431732B

CN110431732B - Brush holder for rotating electrical machine

Info

Publication number: CN110431732B
Application number: CN201880017252.1A
Authority: CN
Inventors: R.本奥姆拉纳; R.莫蒂尔; C.蒙泰伊; D.穆伊尔拉德
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2017-03-15
Filing date: 2018-03-08
Publication date: 2022-06-07
Anticipated expiration: 2038-03-08
Also published as: KR102220795B1; FR3064133A1; CN110431732A; WO2018167398A1; KR20190113960A; FR3064133B1

Abstract

The present invention relates to a rotating electrical machine (10) comprising: -an active component (12, 15) comprising: -a housing (11) surrounding the active component and comprising at least one bearing (16, 17); and-a brush holder (24) comprising: -at least one brush (23) allowing to supply one of the active components with electricity; -a housing (37) formed of an electrically insulating material, the housing comprising a shell (39) at least partially containing brushes and an attachment portion allowing the brush holder to be attached to a part of a rotating electrical machine, characterized in that the brush holder comprises an anti-tilting device (41), the bearing comprises a holding device (44), and the anti-tilting device and the holding device are arranged to cooperate with each other.

Description

Brush holder for rotating electrical machine

Technical Field

The present invention relates particularly 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 machines. It is to be remembered that a reversible machine is a rotary electric machine that can work reversibly, firstly as a generator functioning as an alternator and secondly as an electric motor, for example in order to start the thermal engine of a motor vehicle.

Conventionally, a rotating electrical machine includes:

-a shaft extending along an axis;

-a rotor mounted on the shaft, the assembly formed by the rotor and the shaft being rotationally movable about the axis of the shaft;

-a stationary stator surrounding the rotor;

-two bearings in which the rotor, the stator and a part of the shaft are arranged; and

-an electronic assembly mounted on one of the bearings and controlling the rotating electrical machine.

In alternator mode, as the rotor rotates, it induces a magnetic field on the stator, which converts the magnetic field into an electric current to power the vehicle's electrical consumers and recharge the battery. In the motor mode, the stator is electrically powered and induces a magnetic field that rotates the rotor.

To induce a magnetic field, the rotor includes a coil wound around a rotor body. The coil is electrically powered by a current collector mounted on a portion of the shaft. The current collector comprises two power supply tracks, each in the shape of a ring, which is overmoulded with an insulating material, and two connection wires, each extending from a respective ring, in order to supply the rotor coil with power.

The rotating electrical machine also comprises a brush holder comprising two brushes designed to be in contact with the supply tracks of the collectors, respectively, and means for supplying power to the brushes, in particular from the electronic assembly. The electrical contact between each brush and the track of the associated collector is ensured by a spring supported on the face of the brush opposite to the face in contact with the track. These springs exert considerable force on the brushes and it is therefore important that the brush holder is well held in place.

The rotating electrical machine is mounted such that:

in a first step, the rotor, the stator and the shaft are mounted in bearings;

-in a second step, positioning the brush holder on one of the bearings;

in a third step, the electronic assembly is positioned on the same bearing as the brush holder, so as to form an electrical connection between the brush and the electronic assembly; and

in a fourth step, the brush holder and the electronic assembly are fixed on the bearing, in particular by screws passing through respective openings formed in the electronic assembly, the brush holder and the bearing, this last screwing step making it possible to ensure a good electrical supply of the brushes.

Furthermore, the brush holder comprises retaining means which make it possible to compress the spring sufficiently to return the brush into its receptacle, so as to position the brush holder opposite the collector. Once the brush holder is fixed on the bearing, the retaining device is pushed into its final position so that it no longer blocks the brushes. Thus, the spring is released and the brush returns into contact with the ring of the collector. This mechanism adds two steps to the assembly process, namely a step of blocking the brushes prior to positioning the brush holder on the bearing, and a step of unlocking the brushes after securing the brush holder with the electronic assembly.

In new swivel motor arrangements, new functionality is added to the electronic components, which results in a substantial increase in the size of the electronic components. Therefore, during assembly of the rotating electrical machine, once the electronic components are installed, the brush holder is no longer accessible, and the brushes can no longer be unlocked. Then, the rotor coil is not supplied with power because the contact between the brush and the collector ring cannot be ensured.

A solution to this problem involves unlocking the brushes prior to positioning the electronic assembly. However, the brush holder is not yet fixed to the bearing because the mechanical connection of the brush holder to the bearing occurs simultaneously with the electrical connection between the brush holder and the electronic assembly. This fixing is thus achieved by means of screws, which fix the brush holder and the electronic assembly. The force exerted by the spring on the brush in contact with the collector ring thus causes a deflecting movement of the brush holder. Thus, the brush holder is no longer correctly positioned. Therefore, the mounting of the electronic assembly cannot be performed, and the contact between the brush and the slip ring is no longer ensured.

Disclosure of Invention

The object of the invention is to make it possible to avoid the disadvantages of the prior art.

To this end, the subject of the invention is therefore a rotating electrical machine, in particular for a motor vehicle. According to the present invention, a rotary electric machine includes:

-an active component, in particular comprising a rotor and a stator;

-a housing surrounding the active component and comprising at least one bearing; and

-a brush holder comprising:

-at least one brush allowing to supply one of the active components with electricity;

-a housing formed of an electrically insulating material, said housing comprising a receptacle at least partially housing a brush, and a fixing portion allowing to fix said brush holder on a portion of a rotating electrical machine;

-an electronic assembly mounted on the housing so as to at least partially cover the brush holder; and

-a fixing means arranged such that the electronic component, the fixing portion of the brush holder and the bearing each comprise an opening allowing passage of said fixing means in order to mechanically connect them together.

Furthermore, according to the invention, the brush holder comprises an anti-tilting device different from the fixing device, and the bearing comprises a holding device. In addition, the anti-roll device and the holding device are designed to cooperate with each other.

The invention makes it possible to prevent the deflection of the brush holder caused by the force exerted by the brush during the unlocking of the brush. Thus, even when the unlocking of the brushes occurs before the fixing of the brush holder, a good positioning of the brush holder and thus a good power supply to the active components is ensured.

According to one embodiment, the anti-tilting device and the retaining device protrude and extend towards each other so as to be in contact with each other when the brushes exert a force on one of the active components of the electric machine, the contact being arranged in a direction perpendicular to the direction in which said device extends.

Preferably, the anti-tilting device and the holding device each extend protrudingly, so that the overlapping surface between the two devices is sufficient to make it possible to hold the brush holder in position when the brush exerts a force on the collector of the rotating electrical machine. For example, the anti-tilt device extends towards the bearing projection along an axial length of more than 4mm, in particular about 6 mm.

According to one embodiment, the anti-tilting device is formed by at least one wall projecting extending from the housing and positioned around the retaining device at least in the direction of the force exerted by the brushes so as to be positioned radially between the axis of the electric machine and said retaining device. In other words, the anti-tilting device surrounds the holding device at least around a sector area which is positioned such that it can resist the force exerted by the brushes.

Preferably, the wall extends according to a circular arc.

Preferably, the anti-tipping device is formed by a wall having a "U" -shaped cross-section in a radial plane, said device projecting axially extending from an axial end wall of the casing, and the two free ends of the "U" are positioned adjacent to the side walls of the casing. Thus, the side walls of the housing and the anti-tipping device completely surround the retaining device.

According to a variant embodiment, the anti-tilting means are formed by two walls, each extending in a radial plane from a lateral wall of the casing and projecting axially from an axial end wall of the casing so as to surround the retaining means in the direction of the force exerted by the brushes.

According to one embodiment, the retaining means is formed by a stud.

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

According to one embodiment, the anti-tipping device extends from the fixed part. Preferably, the anti-tipping device extends axially from the fixed part of the housing.

According to one embodiment, the anti-tilt device is in one piece with the housing. In other words, the anti-roll device is integral with the housing.

Preferably, the brush holder is completely covered by the electronic assembly.

According to one embodiment, the brush holder further comprises at least one power supply track having a first connection portion for connection with the electronic component and a second connection portion for connection with the brush. In this embodiment, the first connection portion is located in the first end wall of the fixture. Also in this embodiment, the anti-tipping device extends from a second end wall of the fixation device opposite the first end wall. Preferably, the first and second end walls are axial end walls of the fixation device. Also preferably, the first connection portion extends facing the electronic component. Preferably, the first connection portion is in contact with an associated track of the electronic component, in particular of the control module. The contact is in particular a direct electrical and mechanical contact.

Preferably, the fixing means make it possible to connect the components mechanically and to electrically connect the tracks of the electronic module and the power supply tracks of the brush holder. This makes it possible to reduce the size of the machine.

Preferably, the fixing means is a screw or a tie rod. Preferably, the respective openings of the electronic assembly, brush holder and bearing are located opposite each other. Preferably, the opening in the bearing is positioned in the holding means. It is also preferred that the fixing means have a thread which cooperates with a tapping present in an opening in the bearing.

According to one embodiment, the electronic assembly comprises a clamping member made of an electrically insulating material and positioned to exert pressure on the supply track of the brush holder and the track of the electronic assembly.

According to one embodiment, the housing comprises a portion of a cylinder which protrudes extending so as to at least partially surround the first connecting portion.

According to one embodiment, the housing comprises a sleeve which projects towards the electronic assembly and is positioned radially between the fixing means and the first connection portion of the brush holder.

According to one embodiment, the brush holder comprises two brushes, which are arranged in two receptacles of the housing, respectively, and which are connected to two power supply rails, respectively. For example, one of the brushes has a positive potential and the other brush has a negative or ground potential. Preferably, the housing and the electronic assembly each comprise electrical insulation means cooperating with each other to insulate the two first connection portions of the two power supply tracks of the brush holder. Preferably, the electrically insulating means of the electronic assembly are present on the clamping part.

According to one embodiment, the brush holder comprises at least one spring element, which extends at least partially into the receptacle of the housing, in order to exert a force on the brush in the radial direction.

According to one embodiment, the brush holder comprises at least one indexing stud which enables the brush holder to be indexed in at least one direction on the bearing. Preferably, the brush holder comprises a first indexing stud enabling the brush holder to be indexed on the bearing in a first direction and a second indexing stud enabling the brush holder to be indexed on the bearing in a second direction perpendicular to the first direction.

According to one embodiment, an electronic assembly includes a control module. Preferably, the electronic assembly further comprises at least one power module and a heat sink on which the power module and/or the control module is mounted.

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

Drawings

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

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

Figure 2 schematically and partially shows a separated partial view of a portion of the machine in figure 1;

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

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

fig. 5 shows schematically and partially a cross-sectional view of the electronic assembly and the area of the brush holder of fig. 3 fixed on the bearing;

figure 6 shows schematically and partially a perspective view of another example of a brush holder according to the invention; and

figure 7 shows schematically and partially a perspective transparent view of the brush holder in figure 6.

Like, similar or analogous elements retain the same reference numbers between figures.

Detailed Description

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

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

The rotary electric machine 10 includes a housing 11. Inside the housing 11, it further includes a shaft 13, a rotor 12 rotating integrally with the shaft 13, and a stator 15 surrounding the rotor 12. The rotary motion of the rotor 12 occurs about the axis X.

In the following description, the terms axial, radial, external and internal relate to an axis X passing through the shaft 13 in the center of the shaft. The axial direction corresponds to the axis X, while the radial orientation corresponds to a plane concurrent with and in particular perpendicular to the axis X. With respect to the radial direction, the term outer or inner is considered relative to the same axis X, wherein the term "inner" corresponds to an element oriented towards the axis or closer to the axis than a second element, and the term "outer" means away 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 supports a

respective ball bearing

18, 19 for rotatably mounting the shaft 13.

At the front bearing 16, a pulley 20 is fixed at the front end of the shaft 13, for example by means of a nut supported on the base of the cavity of the pulley. This pulley 20 makes it possible to transmit the rotary motion to the shaft 13 or to make the shaft 13 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 slip ring 21 overmoulded in the body. The slip ring 21 has an annular shape and rotates together with the rotor 12. Brushes 23 belonging to a brush holder 24 are positioned 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 so as to allow cooling of the rotating electrical machine by 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 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 may comprise a conduit allowing the passage of cooling fluid.

In this example, the rotor 12 is a claw rotor. 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 shape. 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 body 27 in the form of a set of metal plates provided with recesses, for example semi-closed or open recesses, equipped with recess insulation for mounting electrical windings 28. The windings 28 pass through notches in the body 27 and form front bun 29 and back bun 30 on either side of the stator body. The windings 28 are connected in a star or delta shape, for example.

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

The electronic assembly 36 comprises at least one electronic power module making it possible to control the phases of the windings 28, and a control module making it possible to control the excitation circuit of the machine 10. The power modules form a current rectifier bridge in order to convert the alternating current generated by the machine 10 into direct current in order to supply, in particular, the battery and the on-board network of the vehicle. Further, the electronic assembly 36 includes a heat sink, which may receive the power module and/or the control module. The heat sink comprises fins that extend out and which guide the cooling air flow for the different modules. According to a variant embodiment, the radiator may comprise ducts for allowing the circulation of a cooling liquid for cooling the different modules. Alternatively, the heat sink may include fins and cooling ducts.

When the electrical winding 28 is electrically powered by the brushes 23, the rotor is magnetized and becomes an inductor rotor, forming north and south magnetic poles at the jaws. The inductor rotor generates an alternating induced current in the induction stator as the shaft rotates. The rectifier bridge then converts this alternating induction current into direct current, in particular in order to supply the loads and consumers of the on-board system of the motor vehicle and to recharge its battery.

As can be seen in the example of fig. 2, a brush holder 24 is mounted on the rear bearing 17, around the current collector 22, the current collector 22 being mounted at the rear end of the shaft 13. An electronic assembly 36 is also mounted on rear bearing 17 and includes a receptacle into which current collector 22 and 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 a different potential to power the rotor coil 35 through the current collector 22. The housing 37 comprises two distinct receptacles 39 into which the 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 direction radial with respect to axis X and has radially opposite inner and outer faces, the inner faces being in contact with relative slip rings 21. In addition, brush holder 24 includes springs 40 positioned in receptacles 39, each spring being associated with a brush 23 and exerting 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 installed 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 collector ring, while compensating for brush wear caused by the rotary motion of the ring.

The brush holder 24 further includes a protective cap 38 extending from an end of the housing 37 in which the receptacle 39 is open. A protective cover 38 surrounds the current collector 22 and the end of the shaft 13. The protective cover thus makes it possible to insulate the respective electrical contacts between the brushes and the slip ring from the external environment.

In order to fit the brush holder 24 around the collector 22, the brush 23 must be held almost completely inside the receptacle 39. In other words, the spring 40 must be sufficiently compressed. For this purpose, means (not shown) for blocking the brush 23 inside the receptacle 39 are used. The device is for example contained in a protective cover 38. It may be formed by a plate that slides to close the receptacle 39. Once the brush holder 24 is in place, the brushes 23 must be released to make contact with the slip rings 21.

In order to prevent tilting of the brush holder 24 caused by the force exerted by the spring 40 during unlocking of the brushes 23, the brush holder 24 comprises an anti-tilting device 41, which is blocked by a retaining device 42 formed on the rear bearing 17. Therefore, the anti-tilting device 41 prevents the brush holder 24 from tilting relative to the bearing 17 in a direction opposite to the direction in which the springs 40 apply force to the brushes 23, respectively.

The anti-tilting device 41 protrudes towards the holding device 42, and the holding device 42 also protrudes so as to be in contact with said anti-tilting device. The contact between the devices occurs in a direction perpendicular to the direction in which the devices extend. In particular, the two

devices

41, 42 extend in axial directions opposite to each other and are in contact with each other by contact of their outer or inner radial ends, respectively. Both devices extend coaxially along an axis substantially parallel to axis X. Contact between the two devices occurs when the brush 23 exerts a force on the collector 22. As a variant, both devices may have dimensions such that the contact is permanent.

In this embodiment, the anti-tipping device 41 is positioned on the side of the housing 37, i.e. on a portion of the brush holder extending between the two radially inner and outer ends of the housing 37. According to a variant embodiment, the anti-tilting device 41 can be positioned on the radially outer end of the casing 37.

According to the embodiment shown in fig. 3 to 7, the anti-tipping device 41 is formed by a wall. The wall preferably extends according to an arc of a circle and at least partially surrounds the retaining means 42. Also in this embodiment, the retaining means 42 is formed by a stud having a substantially cylindrical shape. Preferably, the wall extends about 180 ° around the retaining means 42. Furthermore, the wall has a "U" shape according to the radial plane of the machine 10, the free end of the "U" shape being obtained from the side wall of the casing 37. During positioning of the brush holder 24 on the rear bearing 17, the brush holder is positioned so that the wall comes back into contact with the stud, or so that the wall and the stud are very close to each other, so that during unlocking of the spring 40, the contact between the two devices blocks the brush holder 24 and prevents it from moving relative to its initial position.

According to a variant embodiment, the anti-tilting device 41 can be formed by two or more walls in the form of circular arcs positioned opposite each other around the retaining device 42. In this embodiment, a first inner wall extends radially between the holder 42 and the collector rail 21, and a second outer wall extends between the holder 42 and a cover 43 of the rotating electrical machine 10 that protects the electronic components 36.

Regardless of the embodiment, the brush holder 24 comprises two power supply tracks 44, each of which is at a different potential and makes it possible to supply the brushes 23 with power. For example, one of the brushes is at a positive potential and the other brush is at a negative or ground potential. Due to the housing 37, the power supply tracks 44 are electrically insulated from each other.

The power supply rail 44 is formed in the same manner. Each track 44 therefore has a first connection portion 45 for connection with the electronic assembly 36, a second connection portion 46 for connection with the associated brush 23, and a connection portion 47 which makes it possible to connect the first and second connection portions to one another.

Preferably, the connecting portion 47 is completely contained in the housing 37 of the brush holder, as shown in fig. 4 and 7.

The second connection portion 46 is electrically connected to a braid (not shown) which is itself connected to the associated brush 23. This second connection portion is housed in an end wall of the casing 37 in a distinct manner so as to enable simplified connection to the braid. In particular, said second connection portion is located in a radially outer end wall of the housing 37. The braid is located inside the corresponding receptacle 39 and is connected to the connecting portion, for example by crimping and/or welding. Alternatively, the second connection portion may be located in the receptacle of the housing rather than on a surface thereof.

The first connection portion 45 is accommodated in the end wall of the housing 37 in a distinct manner. The wall faces the electronic component 36. Preferably, it is an axial end wall of the housing 37.

As can be clearly seen in fig. 5, each first connection portion 45 is preferably in direct contact with an associated track 48 of the electronic assembly 36, in particular a track of the control module. The fixing means 49 make it possible to ensure contact between the rail 48 and the first connection portion 45. For example, the housing 37 and the electronic assembly 36 each include openings that are positioned opposite each other to allow the passage of the fixture 49. The fixing means 49 are for example screws or tie rods. In this example, the first connecting portion 45 has a circular arc shape, and is positioned around an opening formed in the housing 37. The two first connection portions 45 of the power supply track 44 are positioned symmetrically with respect to the opening. The rails 48 of the electronic assembly 36 each have a shape adapted to the first connection portion 45 with which they are in contact. The tracks 48 of the electronic assembly 36 may extend proud of the control module or may be overmolded with an electrically insulating material while maintaining an apparent portion for connection with the power supply tracks 44 of the brush holder 24.

The electronic assembly 36 comprises a clamping member 50, the clamping member 50 being made of an electrically insulating material and being positioned to exert a pressure on the assembly formed by the first connection portion 45 of the power supply track 44 of the brush holder and the track 48, in order to ensure a good electrical contact. The clamping member is positioned between a portion of the fixture 49, such as a screw head, and the track 48. It may also electrically insulate the device 49 to secure the track 48.

Preferably, the electronic assembly 36 may also include a washer 60 positioned between a portion of the fixture 49 and the clamping member 50.

In the example shown in fig. 3 to 7, the fixing means 49 allowing electrical contact between the power supply rail 44 and the rail 48 also make it possible to fix the brush holder 24 on the rear bearing 17. To this end, the rear bearing 17 comprises an opening positioned facing a corresponding opening in the electronic assembly 36 and the brush holder 24, so as to allow the passage of the fixing means 49. Preferably, the opening in the rear bearing 17 has a threaded portion that mates with the threaded portion of the fixture 49.

Further, the housing 37 of the brush holder 24 includes a fixing portion that supports the first connecting portion 45 and an opening through which the fixing device 49 passes. The anti-tilt device 41 extends from the fixed part. In particular, the device extends from an axial end wall of the fixed part, opposite the axial end wall facing the electronic assembly. In addition, an opening in the rear bearing 17 is formed in the holding device 42. Preferably, the opening in the electronic assembly 36 is formed in the clip member 50.

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, which first indexing stud 58 allows the brush holder to be indexed on the bearing in a first direction, and a second indexing stud 59, which second indexing stud 59 allows the brush holder to be indexed on the bearing in a second direction perpendicular to the first direction.

The rotating electrical machine 10 operates with positive and negative excitation, with a variable potential difference, typically in the range of 10V to 60V, depending on the application. The power supply rails 44 of the brush holder 24 are connected to positive and negative excitation potentials, respectively. Preferably, different conductive parts of the machine having different potentials may be insulated from each other to prevent the formation of salt bridges.

By avoiding the formation of salt bridges, the anti-tilting device 41 makes it possible to electrically insulate the retaining device 42 formed in the rear bearing 17 of the first connecting portion 45. Preferably, the anti-tilting device 41 extends over at least 4mm, in particular over 6mm, protruding towards the bearing.

In the embodiment shown in fig. 3 to 5, the housing 37 comprises a portion of a cylinder 51 which extends projecting axially towards the electronic assembly 36 and forms an arc of a circle at least partially surrounding the assembly formed by the first connecting portion 45 and the track 48. A portion of the cylinder 51 makes it possible to electrically insulate the assembly from the external environment.

Also in the example shown in these figures, the housing 37 comprises a sleeve 52, which extends axially projecting towards the electronic assembly 36. The sleeve 52 is positioned between the fixing device 49 and the assembly formed by the first connection portion 45 of the brush holder 24 and the track 48 of the electronic assembly 36, so as to surround said fixing device 49. The sleeve 52 makes it possible to electrically insulate the fixing means 49 in contact with the rear bearing 17 of the assembly.

Also in the example shown in these figures, the housing 37 comprises a partition 53, which extends projecting axially towards the electronic assembly 36. The partition 53 is positioned between the two first connection portions 45 of the two power supply tracks 44 in order to electrically insulate them from each other and prevent the formation of salt bridges. Preferably, the housing 37 includes two dividers 53 positioned opposite each other between each end of the first connection section 45.

In all these examples, the gripping member 50 comprises grooves or cavities making it possible to house a portion of the cylinder 51, the sleeve 52 and the partition 53, respectively.

The example in fig. 6 and 7 shows a modified embodiment in which a part of the cylinder 51, the sleeve 52 and the partitioning member 53 are formed on the holding member 50. Then, the housing 37 includes a first groove 54 that makes it possible to accommodate a portion of the cylinder 51, a second groove 55 that makes it possible to accommodate the sleeve 52, and a cavity 56 that makes it possible to accommodate the partition 53.

The invention is particularly applicable in the field of brush holders for alternators or reversible machines, but it can also be applied to any type of rotary machine.

It is to be understood that the foregoing description is provided purely by way of example and does not limit the field of the invention, which may not constitute a departure from the invention by replacing various elements with any other equivalent. For example, no deviation from the scope of the invention is constituted by placing the anti-tilting means on the bearing and the retaining means on the brush holder.

Claims

1. An electric rotating machine, the machine (10) having an axis (X), comprising:

-an active component;

-a housing (11) surrounding the active component and comprising at least one bearing (16, 17);

-a brush holder (24) comprising:

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

-a housing (37) formed of an electrically insulating material, comprising a housing (39) that at least partially houses a brush (23), and a fixing portion that allows fixing the brush holder (24) on a portion of a rotary electric machine (10);

-an electronic assembly (36) mounted on the casing (11) so as to at least partially cover the brush holder (24); and

-a fixing means (49) arranged such that the electronic assembly (36), the fixing portion of the brush holder (24) and the bearing (16, 17) each comprise an opening allowing passage of said fixing means in order to mechanically connect them together,

the rotating electric machine is characterized in that the brush holder (24) comprises an anti-tilting device (41) distinct from the fixing device (49), the bearing (16, 17) comprises a holding device (42), and the anti-tilting device and the holding device are designed to cooperate with each other.

2. The rotating electric machine according to claim 1, characterized in that the rotating electric machine is used for a motor vehicle.

3. A rotating machine according to claim 1, characterized in that the active components comprise a rotor (12) and a stator (15).

4. A rotating electric machine according to claim 1, characterized in that the anti-tilting device (41) and the holding device (42) are protrudingly extended towards each other so as to be in contact with each other when the brushes (23) exert a force on one of the active components of the electric machine (10), the contact being arranged in a direction perpendicular to the direction in which the anti-tilting device and the holding device extend.

5. A rotating electric machine according to any of claims 1-4, characterized in that the anti-tilting means (41) is formed by at least one wall projecting from the housing (37) and positioned around the holding means (42) at least in the direction of the force exerted by the brushes (23) so as to be positioned radially between the axis (X) of the electric machine (10) and the holding means (42).

6. A rotating electric machine according to any of claims 1-4, characterized in that the anti-tilting device (41) is formed by a wall having a "U" -shaped cross-section in a radial plane, the wall extending projecting axially from an axial end wall of the casing (37), and the two free ends of the "U" shape being located adjacent to the side walls of the casing (37).

7. A rotating electric machine according to any of claims 1-4, characterized in that the holding means (42) is formed by a stud.

8. A rotating electric machine according to any of claims 1-4, characterized in that the anti-tilt device (41) extends from the stationary part.

9. A rotating electric machine according to any of claims 1-4, characterized in that the brush holder (24) further comprises at least one power supply track (44) having a first connection portion (45) for connection with the electronic component (36) and a second connection portion (46) for connection with the brush (23), the first connection portion being located in a first end wall of the stationary portion, and the anti-tilting means (41) extending from a second end wall of the stationary portion opposite the first end wall.

10. A rotating electric machine according to claim 9, characterized in that the housing (37) comprises a portion of a cylinder (51) which projects so as to extend at least partially around the first connection portion (45).

11. A rotating electric machine according to claim 9, characterized in that the housing (37) comprises a sleeve (52), the sleeve (52) projecting towards the electronic assembly (36) and being positioned radially between the fixing means (49) and the first connection portion (45) of the brush holder (24).

12. A rotating electric machine according to any of claims 1-4, characterized in that the brush holder (24) comprises at least one indexing stud (58, 59) enabling the brush holder to be indexed in at least one direction on the bearing (16, 17).

13. A rotating electric machine according to any of claims 1-4, characterized in that the anti-tilting device (41) extends protrudingly towards the bearing (16, 17) along an axial length of more than 4 mm.

14. The rotating machine of claim 13 wherein the axial length is 6 mm.

15. The rotating electrical machine according to any one of claims 1 to 4, forming an alternator.

16. The rotary electric machine according to any one of claims 1 to 4, forming an alternator-starter.

17. The rotating electrical machine according to any one of claims 1 to 4, forming a reversible machine.

18. A rotating electric machine according to any of claims 1-4, characterized in that the electronic assembly comprises a control module, at least one power module and a heat sink, on which the power module and/or control module is mounted.