WO2018020187A1

WO2018020187A1 - Rotating electrical machine provided with phase outputs pressed by clamping against conductive tracks

Info

Publication number: WO2018020187A1
Application number: PCT/FR2017/052132
Authority: WO
Inventors: Dominique Mouillard; Christophe Leborgne; Lionel DELECROIX
Original assignee: Valeo Equipements Electriques Moteur
Priority date: 2016-07-28
Filing date: 2017-07-28
Publication date: 2018-02-01
Also published as: FR3054751A1

Abstract

The invention mainly relates to a rotating electrical machine, comprising: - a bearing (18), - a stator (16) carried by said bearing (18), the stator (16) being provided with a stator body (43) and a coil having a plurality of phase windings (48), each phase winding (48) having an end forming a phase output (50), and - a power electronics module (51), characterised in that each phase output (50) is mounted pinched between an insulating support (54) abutting against said bearing (18) and a corresponding connection track (62) electrically connected to said power electronics module (51), the pinching of each phase output (50) being obtained by axially clamping said power electronics module (51) on the bearing (18) by means of an attachment member.

Description

ROTATING ELECTRIC MACHINE HAVING PHASE OUTPUTS PLATED BY CLAMPING AGAINST CONDUCTIVE TRACKS

The invention relates to a rotary electrical machine provided with phase outputs clamped against conductive tracks. 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. Such a reversible alternator is called an alternator-starter and makes it possible to convert electrical energy into mechanical energy, in particular for starting the engine of the vehicle. The invention may also be implemented with an electric motor.

In a manner known per se, an alternator or an alternator-starter comprises a housing and, inside thereof, a rotor with claws, integral in rotation with a shaft, and a stator which surrounds the rotor with presence of a gap.

The rotor comprises a body formed by a stack of sheets of sheet metal held in pack form by means of a suitable fastening system. The rotor comprises poles formed for example by permanent magnets housed in cavities formed in the magnetic mass of the rotor. Alternatively, in a so-called "salient" poles architecture, the poles are formed by coils wound around rotor arms.

Furthermore, the stator comprises a body consisting of a stack of thin sheets forming a ring, whose inner face is provided with notches open inwardly to receive phase windings. These windings pass through the notches of the stator body and form buns protruding from both sides 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. These windings are polyphase windings whose ends corresponding to phase outputs are connected to an electronic power module including a bridge rectifier in the case of an alternator.

In order to ensure the electrical connection of the phase outputs with the electronic power module, the phase outputs are conventionally fixed on lugs, which are screwed on corresponding connectors of the electronic power module.

However, in some alternator-starter configurations, access to the connection areas on the electronic power module can be made difficult due to the presence, imposed by the motor vehicle manufacturer, of a wall of the machine support. extending in front of the fixing interfaces.

The invention aims to allow the connection between the phase outputs and the electronic power module regardless of the configuration of the alternator support.

To this end, the invention proposes a rotating electrical machine comprising:

- a step,

a stator carried by said bearing, said stator being provided with a stator body and a coil having a plurality of phase windings, each phase winding having an end forming a phase output, and an electronic module power,

characterized in that each phase output is mounted wedged between an insulating support bearing against said bearing and a corresponding connection track electrically connected to said electronic power module, said jamming of each phase output being obtained by axial clamping of said electronic module of power on said bearing via at least one fastener.

The invention thus facilitates the establishment of connections between the phase outputs and the connection tracks because of the contacts obtained during the mounting of the electronic power module on the bearing of the machine. The connections can then be made whatever the shape of the alternator support. In addition, because of the removal of the lugs, the invention is of economic interest. According to one embodiment, an elastic element is mounted compressed between said connection track and an end face of said power electronic module. This makes it possible to absorb the mounting sets of the system and to keep the fastener in tension in order to maintain the pressure force between the connection track and the corresponding phase output.

In one embodiment, said connection track belongs to a connection medium.

According to one embodiment, said connection track is extended by a tab having a fixing interface on the side of its free end to attach to said power electronic module. This makes it possible to authorize a remote connection between the phase outputs of the machine and the electronic power module.

According to one embodiment, said connection track and said tab have an L-shaped. This makes it possible to ensure a remote connection of the connection track in a radially oriented face of the electronic power module.

According to one embodiment, said tab and said connecting track are overmolded by a portion of plastic material.

According to one embodiment, said phase output is folded against said insulating support.

According to one embodiment, said insulating support comprises lateral retention means of said phase output.

According to one embodiment, said rotating electrical machine comprises a plurality of connection supports interconnected by said elastic element.

According to one embodiment, said connection supports are interconnected by thermoforming the elastic element on said overmolded plastic portion of each connection support.

According to one embodiment, said connection supports are connected between they snap said elastic element onto said overmolded plastic portion of each connection support.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given for illustrative but not limiting of the invention.

Figure 1 is a longitudinal sectional view of a rotary electric machine according to the present invention;

FIG. 2a shows a detailed sectional view illustrating the connection between a phase output and a connection track connected to the electronic power module;

Figure 2b is a sectional view along the axis C-C of Figure 2a;

Figure 3a is a perspective view of an electronic power module mounted on the rear bearing of the rotating electrical machine according to the present invention; Figure 3b is a perspective view showing the rear face of the power electronics module including the connection tracks;

FIG. 4 is a perspective view illustrating the folded positioning of the phase outputs against the rear bearing of the rotating electrical machine according to the invention; Figures 5a and 5b are perspective views showing a set of connection supports according to the invention.

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

FIG. 1 shows a compact and polyphase alternator 10, in particular for a motor vehicle. The alternator 10 is able to transform mechanical energy into electrical energy and may be reversible. Such a reversible alternator, called alternator-starter, makes it possible to convert electrical energy into mechanical energy, in particular to start the engine of the vehicle. This alternator 10 comprises a casing January 1 and, inside thereof, a claw rotor 12 mounted on a shaft 13, and a stator 16, which surrounds the rotor 12 with the presence of an air gap between the outer periphery of the rotor 12 and the internal periphery of the stator 16. The axis X along which the shaft 13 extends forms the axis of rotation of the rotor 12.

The casing 1 1 comprises front 17 and rear 18 bearings bearing the stator 16. The bearings 17, 18 are of hollow form and each carry a central ball bearing 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 a wheel 24, 25 are directed axially towards the flange 28 of the other wheel. The claws 29 of a pole wheel 24, 25 penetrate the space between two claws 29 adjacent to the other pole wheel, so that the claws 29 of the pole wheels 24, 25 are interleaved relative to each 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 at its outer periphery a excitation winding 31 wound in an insulator 32 inserted radially between the core 30 and the coil 31.

The shaft 13 can be force-fitted into the central bore of the pole wheels 24, 25. On the side of its front end, the shaft 13 may comprise a threaded portion for fixing a pulley 35. The pulley 35 belongs to a device for transmitting movements to at least one belt between the alternator 10 and the engine of the motor vehicle.

The rear bearing 18 carries a brush holder 38 provided with brushes 39 intended to rub against rings 40 of a collector 41 to supply the winding of the rotor 12. Furthermore, the stator 16 comprises a body 43 in form a sheet metal package with notches equipped with notch insulation for mounting the phases of the stator 16. Each phase comprises at least one winding 48 passing through the notches of the stator body 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 48 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.

As can be seen in FIG. 2a, each phase winding 48 comprises an end forming a phase output 50 connected to an electronic power module 51. This module 51 comprises in particular a rectifier bridge constituted for example by diodes or transistors of the MOSFET type.

As shown in FIG. 4, the phase outputs 50 are each folded against an electrically insulating support 54 in abutment, preferably fixed on the rear bearing 18. Each insulating support 54 comprises lateral retaining means 55 of the output phase 50. These retaining means 55 are for example constituted by side walls of a housing 56 formed in the support 54 and intended to receive a corresponding phase output 50. Advantageously, the insulating supports 54 are mechanically connected to each other via a connecting strip 57 in order to facilitate their installation on the rear bearing 18.

Moreover, as is clearly visible in FIG. 3a, 3b, 5a, and 5b, connection supports 61 each comprise a connection track 62 intended to come into contact with a corresponding phase output 50 as well as a tab 63 located in the extension of the track 62.

Each lug 63 has an attachment interface 64 on its free end side, that is to say on the side opposite its connection zone with the connection track 62. The attachment interface 64 allows the lug 63 to attach to the power electronics module 51. The attachment interface 64 may for example take the form of an opening allowing the passage of a fastener 67 of the screw type to establish a contact between a portion of the tab 63 and a corresponding conductive portion of the module 51, as shown in FIG. than this is shown in Figures 2a and 3a.

Preferably, the connection track 62 and the tab 63 are made in one piece in an electrically conductive material. The track 62 and the lug 63 have an L shape. This makes it possible to ensure a remote connection of the connecting track 62 along a face of radial orientation of the module 51 with respect to the fixing area of the connection support 61 located on a lateral face of axial orientation of the module 51.

In addition, in order to ensure electrical insulation, each connection support 61 comprises a plastic portion 68 molded around the fastening tab 63 and the connection track 62. The plastic portion 68 may form visible edges 69 in Figures 2b and 5b, intended to extend on either side of the phase output 50 to ensure its lateral maintenance once the assembly is made.

As can be seen in FIGS. 5a and 5b, the connection supports 61 may be mechanically connected to one another by an elastic element 71. The elastic element 71 may be obtained for example by a strip of plastic material whose elastic effect is obtained by the production of corrugations having an alternation of hollow 72 and vertices 73. The connection supports 61 may be interconnected by thermoforming the elastic element 71 on the plastic portion 68 overmolded of each support 54 connection. For this purpose, a stud 76 coming from one face of each plastic portion 68 opposite to the connecting track 62 cooperates with a corresponding opening 77 made in a hollow 72 of the elastic element 71.

Alternatively, the connection supports 61 are interconnected by snap-fastening of the elastic element 71 on the plastic portion 68 molded on each connection support 54.

As is clear from Figures 2a and 2b, each phase output 50 is mounted wedged between the insulating support 54 bearing against the rear bearing 18 and a corresponding connection track 62 connected electrically to the power electronics module 51. The jamming of each phase output 50 is obtained by axial clamping of the power electronics module 51 on the rear bearing 18 via at least one fastener 78, such as a screw or tie visible in Figure 3a. The axial clamping has the effect of compressing the elastic element 71 between the connection track 62 and the end face 79 of the power electronic module 51. The elastic element 71 then exerts by reaction an axial force on the connection support 61 to maintain contact between the connection track 62 and the phase output 50. The elastic element 71 in this case bears against a radial face 79 of a heat sink 80 carrying positive rectifying elements.

The use of the elastic element 71 thus makes it possible to absorb the mounting slots of the system and to keep the fastener 78 in tension in order to maintain the pressure force between the connection track 62 and the phase output 50. corresponding.

In an alternative embodiment, the connection track 62 is not made in a connection support 61 but belongs to the power electronic module 51 in the form of an integrated circuit of electronic circuit. The invention has been described with reference to an alternator 10 or an alternator-starter but it may also be implemented with an electric motor or any other electrical machine comprising a winding provided with phase outputs 50 intended to be connected to a terminal. electronic power module 51. Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention which would not be overcome by replacing the different elements by any other equivalent.

Claims

1. Rotating electrical machine (10) comprising:

- a bearing (18),

a stator (16) carried by said bearing (18), said stator (16) being provided with a stator body (43) and a coil having a plurality of phase windings (48), each winding of phase (48) having an end forming a phase output (50), and

an electronic power module (51),

characterized in that each phase output (50) is mounted wedged between an insulating support (54) bearing against said bearing (18) and a corresponding connection track (62) electrically connected to said power electronic module (51), said jamming of each phase output (50) being obtained by axial clamping said power electronic module (51) on said bearing (18) via at least one fastener (78).

2. A rotary electric machine according to claim 1, characterized in that a resilient element (71) is compressed between said connecting track (62) and an end face (79) of said power electronic module (51).

3. Rotating electrical machine according to claim 1 or 2, characterized in that said connection track (62) belongs to a connection support (61).

4. rotary electrical machine according to claim 3, characterized in that said connecting track (62) is extended by a tab (63) having a fixing interface (64) on the side of its free end to attach to said electronic module of power (51).

5. Rotating electrical machine according to claim 4, characterized in that said connecting track (62) and said tab (63) have an L shape.

6. rotary electric machine according to claim 4 or 5, characterized in that said lug (63) and said connecting track (62) are overmolded by a plastic portion (68).

7. rotary electric machine according to any one of claims 1 to 6, characterized in that said phase output (50) is folded against said insulating support (54).

8. rotary electrical machine according to any one of claims 1 to 7, characterized in that said insulating support (54) comprises lateral retaining means (55) of said phase output (50).

9. Rotating electrical machine according to claims 2 and 3, characterized in that it comprises a plurality of connection supports (61) interconnected by said elastic member (71).

10. A rotary electric machine according to claims 6 and 9, characterized in that said connection supports (61) are interconnected by thermoforming the elastic element (71) on said molded plastic portion (68) of each connection support (61).

1 1. Rotary electric machine according to claims 6 and 9, characterized in that said connecting supports (61) are interconnected by snapping said elastic member (71) on said molded plastic portion (68) of each connection support (61).