FR3071372A1 - IMPROVED VOLTAGE REGULATOR FOR ROTATING ELECTRICAL MACHINE - Google Patents

Abstract

The invention relates mainly to a voltage regulator (78) at the terminals of a rotor winding of a rotating electrical machine, in particular for a motor vehicle, comprising: a body (79) provided with housings (38) for brooms and tracks conductors (81), - an electronic control module (84) provided with connection terminals (98), characterized in that the electronic control module (84) is integrated in a heat sink (104) comprising fixing means ( 111) with the regulator body (79), the connection terminals (98) of the electronic control module (84) being electrically connected to the conductive tracks (81).

Description

IMPROVED VOLTAGE REGULATOR FOR ROTATING ELECTRIC MACHINE

The present invention relates to an improved voltage regulator for a rotary electrical machine. The invention finds a particularly advantageous, but not exclusive, application in the field of alternators for motor vehicles. Such an alternator transforms mechanical energy into electrical energy and can be reversible.

In a manner known per se, an alternator comprises a casing and, inside thereof, a claw rotor, integral in rotation with a shaft, and a stator which surrounds the rotor with the presence of an air gap.

The rotor has two pole wheels each having a transverse orientation flange provided at its outer periphery with claws of axial orientation. The claws of the pole wheels are nested relative to each other. A cylindrical core is interposed axially between the flanges of the wheels. This core carries at its outer periphery an excitation winding formed around an insulating element radially interposed between the core and the winding.

Furthermore, the stator comprises a body constituted by a stack of thin sheets forming a crown, the inner face of which is provided with notches open towards the inside to receive phase windings. These windings pass through the notches in the stator body and form buns protruding from either side of the stator body. The phase windings are obtained for example from a continuous wire covered with enamel or from conductive elements in the form of pins connected together by welding.

The phase windings are electrically connected to electronic power modules via their phase output. These power modules form a voltage rectifier bridge. Generally, each power module comprises a control unit capable of driving rectifier elements constituted for example by transistors, in particular of the MOSFET type.

A brush holder has housings for brushes intended to rub against the rings of a collector carried by the shaft in order to supply the winding of the rotor. The brush holder is associated with an electronic control module in order to regulate the voltage across the rotor winding. However, the new functions desired by automobile manufacturers, such as for example a regenerative braking function or assistance in stopping the heat engine, involve the installation of additional components that are too bulky to be installed in current brush holders.

The invention aims to effectively remedy these drawbacks by proposing a voltage regulator at the terminals of a rotor winding of a rotating electric machine, in particular for a motor vehicle, comprising a body provided with housings for brushes and conductive tracks and an electronic module. control with connection terminals. According to the invention, the electronic control module is integrated in a heat sink comprising fixing means with the regulator body, the connection terminals of the electronic control module being electrically connected to the conductive tracks.

The invention thus makes it possible, owing to the integration of the electrical control module in the heat sink, to easily embed in the brush holder an electronic control module which can integrate functions in addition to regulation, such as in particular the electric energy recovery function when braking the vehicle. Indeed, according to the requirements of the automobile manufacturer, it will be possible to install a simple module performing only the voltage regulation function or a complex module performing additional functions, without modifying the architecture of the rotating electrical machine.

According to one embodiment, the conductive tracks are overmolded in the regulator body.

According to one embodiment, the electronic control module is positioned in a corresponding housing provided in the heat sink.

According to one embodiment, a layer of adhesive is interposed between the electronic control module and the heat sink.

According to one embodiment, the terminals of the electronic control module are electrically connected to the conductive tracks in welding zones, in particular of the laser type.

According to one embodiment, the means for fixing the dissipator include at least two holes for the passage of fixing members.

According to one embodiment, the heat sink includes cooling fins.

According to one embodiment, said voltage regulator comprises:

- a ground connection interface,

- a connection interface with positive potential,

- a connection interface with an external control system, and

- an interface for receiving phase signals to ensure voltage regulation.

According to one embodiment, said voltage regulator is configured to perform a function of regulating a voltage applied to a rotor winding as well as a function of recovering electrical energy during braking of the motor vehicle.

According to one embodiment, the heat sink has a shape complementary to the electronic control module, in particular parallelepiped.

The invention also relates to a rotating electrical machine, in particular for a motor vehicle. The machine includes a voltage regulator as previously defined.

According to one embodiment, the machine further comprises a bearing on which is mounted, at least in part, the voltage regulator.

According to one embodiment, the machine further comprises a rectifier bridge comprising rectifier elements and associated with a heat sink.

According to one embodiment, the machine further comprises a connector for establishing a connection between phases of the rotary electrical machine and the rectifier elements of the rectifier bridge.

According to one embodiment, the rectifier elements are transistors, in particular of the MOSFET type.

According to one embodiment, the rectifier elements are diodes.

According to one embodiment, the machine further comprises at least one heat sink supporting rectifier elements, the voltage regulator extending at least partly in a radial plane which passes through the heat sink. For example, the voltage regulator extends between two free ends of the heat sink.

According to one embodiment, the heat sink of the voltage regulator extends along its thickness between a transverse external face of the rear bearing and a face of the regulator body facing the rear bearing. This provides an axially compact configuration of the assembly. Alternatively, the heat sink of the voltage regulator may extend along its thickness between a cover of the machine and a face of the regulator body facing said cover, that is to say opposite to the face of the regulator body making facing the rear landing.

The rotating electric machine forms, for example, an alternator or an alternator-starter.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 is a longitudinal sectional view of a rotary electrical machine according to an example of the present invention.

Figure 2 is a perspective view of the rear end of the machine according to a first variant of the invention comprising a transistor rectifier bridge.

Figure 3 is a perspective view of the assembly formed by a connector and a heat sink integrating the electronic power modules of the machine according to the example of Figure 2.

FIG. 4 is an exploded perspective view of the electronic power modules and of the heat sink of the machine according to the example of FIG. 2.

Figure 5 is a perspective view of a voltage regulator according to the example of Figure 2.

Figure 6 is a perspective view from below of a voltage regulator according to the example of Figure 2.

Figure 7 is an exploded perspective view of a voltage regulator according to the example of Figure 2.

Figures 8a and 8b are perspective views of the rear end of the machine according to an alternative embodiment of the invention comprising a diode rectifier bridge respectively with and without the heat sink-connector assembly.

Identical, similar, or analogous elements keep the same reference from one figure to another.

FIG. 1 shows a compact and polyphase tournelO electric machine, in particular for a motor vehicle. The machine can form an alternator 10 capable of transforming mechanical energy into electrical energy and which may be reversible. Such a reversible alternator, called an alternator-starter, makes it possible to transform electrical energy into mechanical energy in particular for starting the thermal engine of the vehicle.

This alternator 10 comprises a casing 11 and, inside thereof, a claw rotor 12 mounted on a shaft 13, and a stator 16, which surrounds the rotor with the presence of an air gap. The axis X along which the shaft 13 extends forms the axis of rotation of the rotor 12.

The casing 11 has front 17 and rear 18 bearings carrying the stator 16. The bearings 17, 18 are hollow in shape and each carry a ball bearing centrally for the rotational mounting of the shaft 13.

More specifically, the rotor 12 comprises two pole wheels 24, 25 each having a flange 28 of transverse orientation provided at its outer periphery with claws 29 for example of trapezoidal shape and axial orientation. The claws 29 of one wheel 24, 25 are directed axially towards the flange 28 of the other wheel. The claws 29 of a pole wheel 24, 25 penetrate into an intermediate space existing between two claws 29 adjacent to the other pole wheel, so that the claws 29 of the pole wheels 24, 25 are nested with respect to the other.

A cylindrical core 30 is interposed axially between the flanges 28 of the wheels 24, 25. In this case, the core 30 consists of two half-cores each belonging to one of the flanges 28. This core 30 carries a rotor winding at its outer periphery excitement 31.

The shaft 13 may be force fitted into the central bore of the pole wheels 24, 25. On the side of its front end, the shaft 13 may include a threaded part for fixing a pulley 35. The pulley 35 belongs to a movement transmission device with at least one belt between the alternator 10 and the engine of the motor vehicle.

Brushes 39 positioned in their housing 38 are intended to rub against rings 40 of a collector 41 to supply the rotor winding 31.

Furthermore, the stator 16 comprises a body 43 in the form of a sheet bundle provided with notches equipped with insulating notches for mounting the phases of the stator 16. Each phase comprises at least one phase winding passing through the notches of the body of stator 43 and forms, with all the phases, a front bun 46 and a rear bun 47 on either side of the stator body 43.

The phase windings are obtained for example from a continuous wire covered with enamel or from conductive elements in the form of pins electrically connected to each other for example by welding.

In a first variant of the invention, the phase windings are electrically connected to electronic power modules 50 via their phase output. These power modules 50 form a voltage rectifier bridge to transform the alternating voltage generated by the alternator 10 into a direct voltage to supply in particular the battery and the on-board network of the vehicle.

In the example of FIG. 4, each power module 50 comprises a control unit 51 capable of driving three bridge arms 52 each comprising two rectifier elements 53. The rectifier elements 53 are for example constituted by transistors of the MOSFET type.

These components 51, 52, 53 as well as other passive components (resistors and capacitors in particular) are installed on an electronic card 54 comprising traces 55 formed in a layer of conductive material in particular a layer of copper. The copper layer covers for example a ceramic layer also carrying a second copper layer on the side opposite to the face of the card 54 carrying the electronic components. In this example, the various components are installed on the card 54 by soldering.

The components 51, 52, 53 are electrically connected to the traces 55 of the electronic card 54 for example by a wired wiring method known as wire bonding in English.

Connection terminals 56 are associated with the various power modules 50 for the interconnection with tracks 59 of a connector 60 described in more detail below.

The power modules 50 are each positioned inside a corresponding housing 61 formed in a heat sink 62. In order to improve the evacuation of the heat diffused by the different modules, a layer of thermally conductive adhesive 65 is interposed between each power module 50 and a bottom of each corresponding housing 61. Preferably, the adhesive layer 65 is deposited between the face of the card 54 bearing no component and the bottom of the housing 61.

Furthermore, the heat sink 62 includes a plurality of fins 67 projecting from an external face of the heat sink 62.

As can be seen in FIG. 3, the connector 60 establishes electrical connections in particular between the terminals 56 of the power modules 50 and the phase outputs of the alternator 10. The connector 60 also establishes electrical connections between the components of the electronic cards 54 and the positive potential via a positive terminal B + referenced 70 (see Figure 2). The positive terminal 70 is, for example, disposed on the heat sink 62. In addition, the connector 60 also establishes electrical connections between the components of the electronic cards 54 and a mass of the vehicle, in particular via the rear bearing 18.

To this end, the connector 60 comprises a body 71, generally in the form of a plate made of insulating material, molded onto a set of conductive tracks 59, some of which have been shown in broken lines. The connections between the terminals 56 of the power modules 50 and the tracks 59 are made for example by laser welding through connection zones 73.

As can be seen in FIGS. 2 and 3 in particular, certain tracks 59 project radially outward from the body of the connector 71, being arranged at their free ends in the form of connection tabs 75 to establish the connection with the phase outputs of the stator winding. In the example shown, the connector 60 comprises two sets of three connection tabs 75 intended to be connected with phase outputs of two three-phase systems.

The electric machine 10 also includes a voltage regulator 78 for regulating the voltage applied to the rotor winding 31.

In addition to the regulation function, the regulator 78 can be configured to perform an energy recovery function during a braking phase of the motor vehicle. It will also be possible to provide for a duplication of the various functions implemented by the electronic module in order to meet the new automotive security standards.

In the example of FIGS. 5, 6 and 7, this regulator 78 comprises a body 79 provided with housings 38 for the brushes 39. The body 79 is overmolded on conductive tracks 81 ensuring an interconnection between the components of an electronic module of control 84 as well as a connection between a first brush 39 and a connection interface 85 to ground and between a second brush 39 and a connection interface 86 to the positive terminal 70. For this purpose, two tracks 81 making it possible to supply the brushes 39 extend between the connection interfaces 85, 86 up to respective welding zones 87, 88 with the braids of the brushes 39.

An added protective element 90 can be fixed for example by snap-fastening via a sliding link on the side of the end of the brushes 39 intended to rub against the rings 40. This protective element 90 positioned around the brushes 39 and the rings 40 makes it possible to ensure the protection of the assembly vis-à-vis the external environment.

In addition, the electronic control module 84 includes a control unit 91 and electronic components 92 located on an electronic card 95, as shown in FIG. 7. This electronic card 95 has traces 96 made in a layer of conductive material including a layer of copper. The copper layer covers for example a ceramic layer also carrying a second copper layer on the side opposite to the face of the card 95 carrying the electronic components. In this example, the various components are installed on the electronic card 95 by soldering.

The components 91, 92 are electrically connected to the traces 96 of the electronic card 95 for example by a wired cabling process known as wire bonding in English.

Connection terminals 98 are associated with the various components of the electronic control module 84. These connection terminals 98 are electrically connected to the conductive tracks 81 in welding zones 101, in particular of the laser type. These weld zones 101 each consist of an opening formed in the body 79 to reveal a portion of the conductive track 81 to be connected. For example, a local widening of the conductive track 81 at the soldering zone 101 is possible.

The regulator 78 may also include a connection interface connecting the electronic control module 84 to a control system (not shown) external to the machine. This external control system is for example the engine computer of the vehicle. This interface allows information to be transferred from the machine to the external control system and vice versa. This transmission of information is done for example by means of a LIN or CAN link.

The electronic control module 84 is integrated into a heat sink 104, that is to say that it is positioned inside a corresponding housing 105 formed in the heat sink 104.

In order to improve the evacuation of the heat diffused by the module, a layer of thermally conductive glue 108 is interposed between the electronic control module 84 and the bottom of the housing 105. Preferably, the glue layer 108 is deposited between the face of the card 95 bearing no component and the bottom of the housing 105.

The heat sink 104 has a shape complementary to the electronic control module 84, in particular parallelepiped. The heatsink 104 has a plurality of fins 109 projecting from an external face of the heatsink.

The heat sink 104 comprises fixing means 111 with the regulator body 79. In this example, the fixing means 111 comprise at least two perforated ears 112, in particular threaded, implanted on the longitudinal edges of the heat sink 104 for the passage of 'fasteners 113, such as screws intended to cooperate with openings in the body 79. Alternatively, self-tapping screws can be used in combination with smooth openings. Other fixing means such as via tie rods or glue can be envisaged. The dissipator can also be positioned by centering pins.

The regulator 78 further comprises a connection interface 85 to ground, a connection interface 86 to the positive potential B + and an interface 116 for receiving phase signals in order to ensure voltage regulation. These interfaces 85, 86, 116 take, for example, the form of an annular eyelet.

In this example, the regulator 78 is mounted on the rear bearing 18 of the electric machine so as to extend between the two free ends of the heat sink 104 generally in a V shape.

In this case, fixing members 117, 118, 119 such as screws, are inserted into the different interfaces 85, 86, 116 to establish a connection between these interfaces 85, 86, 116 and corresponding connection elements.

Thus, the screw 117 is inserted inside the hole of the interface for connection 85 to the ground and the hole in coincidence of the projecting chimney 121 of the bearing 18 electrically connected to the ground.

The screw 118 is inserted inside the hole of the connection interface 86 at the positive potential B + and the hole in coincidence with a protruding stud 122 of the heat sink 104 connected to the positive potential.

A screw 119 is inserted inside the hole of the interface for receiving the phase signals 116 and the hole in coincidence with the stud 123 connected to the track 81 on which the phase signals circulate in order to ensure regulation. The regulator 78 receives two phase signals from the same three-phase system.

Given the raised mounting of the regulator 78 relative to the transverse external face of the rear bearing 18, the heat sink 104 may extend along its thickness between the transverse external face of the rear bearing 18 and a face of the regulator body 79 facing the rear bearing 18. This gives an axially compact configuration. It is specified here that the transverse external face of the bearing 18 is turned on the opposite side axially with respect to the internal active elements (rotor and stator) of the rotary electric machine 10. Alternatively, the heat sink 104 may extend according to its thickness between a cover of the machine and one face of the regulator body 79 facing the cover, the face facing the cover being axially opposite to that facing the bearing.

Alternatively, in the embodiment of Figures 8a and 8b, the rectifier bridge has diodes 125, 126 in place of the transistors. There is thus a first group of diodes 125 fitted into the bearing 18 connected to ground visible in FIG. 8b and a second group of diodes 126 fitted into the heat sink 104 connected to the positive terminal visible in FIG. 8a. The diodes 125, 126 are connected to each other via their projecting rod by means of the connector 60. Alternatively, the machine may comprise two heat sinks each carrying diodes.

The configuration of the voltage regulator 78 remains unchanged compared to that used with a transistor rectifier bridge.

Alternatively, the alternator 10 may in particular comprise a single three-phase system.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention from which one would not depart by replacing the various elements with any other equivalent.

Furthermore, the various features, variants, and / or embodiments of the present invention can be combined with one another in various combinations, insofar as they are not incompatible or mutually exclusive of one another.

Claims (11)

1. Voltage regulator (78) across a rotor winding (31) of a rotating electric machine (10), in particular for a motor vehicle, comprising: a body (79) provided with housings (38) for brushes (39) and conductive tracks (81), - an electronic control module (84) provided with connection terminals (98), characterized in that the electronic control module (84) is integrated in a heat sink (104) comprising fixing means (111) with the body regulator (79), the connection terminals (98) of the electronic control module (84) being electrically connected to the conductive tracks (81). 2. Regulator (78) according to claim 1, characterized in that a layer of adhesive (108) is interposed between the electronic control module (84) and the heat sink (104). 3. Regulator (78) according to claim 1 or 2, characterized in that the terminals (98) of the electronic control module (84) are electrically connected to the conductive tracks (81) in soldering zones (101), in particular of laser type. 4. Regulator (78) according to any one of claims 1 to 3, characterized in that the fixing means (111) of the dissipator comprise at least two perforated ears (112) for the passage of fixing members (113) . 5. Regulator (78) according to any one of claims 1 to 4, characterized in that the heat sink (104) comprises cooling fins (109). 6. Regulator (78) according to any one of claims 1 to 5, characterized in that it comprises: - a connection interface (85) to a ground, - a connection interface (86) with a positive potential, - a connection interface with an external control system, and - a reception interface (116) of phase signals in order to ensure voltage regulation. 7. Regulator (78) according to any one of claims 1 to 6, characterized in that it is configured to perform a function of regulating a voltage applied to a rotor winding as well as an energy recovery function electric when braking the motor vehicle. 8. Regulator (78) according to any one of claims 1 to 7, characterized in that the heat sink (104) has a shape complementary to the electronic control module (84), in particular parallelepiped. 9. Rotating electric machine (10) in particular for a motor vehicle, characterized in that it comprises a voltage regulator (78) as defined in any one of the preceding claims. 10. Machine according to claim 9, characterized in that it further comprises at least one heat sink (62) supporting rectifying elements (53, 125, 126), the voltage regulator (78) extending at at least partly in a radial plane which crosses the heat sink (62). 11. Machine according to claim 9 or 10, characterized in that the heat sink (104) of the voltage regulator (78) extends along its thickness between a transverse external face of the rear bearing (18) and a face of the body of regulator (79) facing the rear bearing.