WO2018178535A1

WO2018178535A1 - Rotating electrical machine with configuration modified to facilitate the mountability of the functional element

Info

Publication number: WO2018178535A1
Application number: PCT/FR2018/050614
Authority: WO
Inventors: Christophe Leborgne
Original assignee: Valeo Equipements Electriques Moteur
Priority date: 2017-03-28
Filing date: 2018-03-14
Publication date: 2018-10-04
Also published as: FR3064841B1; FR3064841A1

Abstract

The invention primarily relates to an assembly for a motor vehicle, comprising: - a rotating electrical machine provided with a first bearing (17) and a second bearing defining an internal volume (65), - a functional element (58), - at least one fastening member (60) passing through a portion (51) of one of the bearings (17) having an inner face turned towards the internal volume (65) and an outer face turned towards the opposite side, characterised in that said fastening member (60) comprises a head (77) located on the side of the inner face of the portion of the bearing (51).

Description

ROTATING ELECTRICAL MODIFIED MACHINE FOR FACILITATING THE MONTABILITY OF A FUNCTIONAL ELEMENT

The present invention relates to a rotating electrical machine with a modified configuration to facilitate the mounting of a functional element. The invention finds a particularly advantageous, but not exclusive, application in the field of alternators for motor vehicles.

In a manner known per se, an alternator comprises a housing 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 housing has a front bearing and a rear bearing centrally bearing a ball bearing for the rotational mounting of the shaft of the machine.

The rotor comprises two pole wheels each having a transversely oriented flange provided at its outer periphery axially oriented claws. The claws of the pole wheels are nested with respect to each other. A cylindrical core is interposed axially between the flanges of the wheels. This core carries at its outer periphery an excitation coil formed around an insulating element inserted radially between the core and the coil.

Furthermore, the stator comprises a body constituted by a stack of thin sheets forming a ring, whose inner face is provided with notches for receiving phase windings. The windings form coil coils extending projecting from either side of the stator body. The phase windings are electrically connected to an electronic control module. This control module comprises a voltage rectifier bridge formed from rectifying elements, such as diodes or transistors.

As can be seen in FIG. 1, a functional element, for example a roller support 1, is fixed on the front bearing 2 by means of fixing screws 3. For this purpose, the screws 3 pass through projecting lugs 4 with holes in the support 1 and cooperate with threaded columns 5 of the bearing 2. Rollers 6 rotatably mounted about axes 7 are intended to come into contact with a belt, which cooperates with the pulley 8 mounted on the shaft of the electric machine.

In the case of a heat engine implanted in a reduced under-hood space, it may arise a problem of mountability of the roller support 1 on the front bearing 2 due to interference between the mounting tool 9 (cf. Figure 2a) used to tighten the fastening screws 3 and a stretcher of the vehicle located nearby.

As shown in FIG. 2b, it was initially envisaged to shift the attachment zone of the roller support 1, but this was likely to generate short circuits in the zone Z1 because of the contact between the screw 3 electrically connected to the ground via the bearing 2 and a stator winding bunt electrically connected to a positive electric potential, for example 12Volts or 48Volts.

As shown in FIG. 2c, it has also been envisaged to reduce the length of the screw, but in this case, the length L1 of the thread engaged with the tapping of the threaded column 5 is insufficient to guarantee a correct fixing of the support. .

The invention aims to effectively remedy this disadvantage by proposing a motor vehicle assembly comprising:

a rotary electric machine provided with a first bearing and a second bearing delimiting an internal volume;

- a functional element,

at least one fastener passing through a portion of one of the bearings having an internal face turned towards the internal volume and an external face turned from the opposite side,

characterized in that said fixing member comprises a head located on the side of the inner face of the portion of the bearing.

The invention thus allows a mounting of the inside to the outside of the fastener allowing a reduction in the length of the mechanical connection between the functional element and the bearing of the electric machine. This therefore avoids the problem of interference between the mounting tool and the stretcher of the vehicle body in the case of a configuration of compact motor.

According to one embodiment, the functional element is a roller support intended to cooperate with a belt, which cooperates with a pulley mounted on a shaft of the rotating electrical machine. According to one embodiment, said bearing portion being constituted by a bearing base, the fastener passes through a thickness of the roller support and a thickness of said bearing base.

In one embodiment, the head of the fastener is located inside the internal volume of the rotating electrical machine. In one embodiment, the fastener passes through the thickness of the bearing floor via a perforated column.

According to one embodiment, a nut is screwed onto a threaded free end of the fixing member located outside the internal volume of the rotating electrical machine. In one embodiment, the functional element is an electronic control module.

According to one embodiment, said bearing portion being constituted by a perforated lug resulting from an outer periphery of a flange of the bearing, the fastener passes through said lug and cooperates with a tapping formed in a body of the electronic control module.

In one embodiment, the fixing member is fitted into a hole in the bearing portion.

According to one embodiment, the fastener is fitted by means of a knurled section. According to one embodiment, said assembly comprises a means of anti-rotation of the fastener.

According to one embodiment, the anti-rotation means is constituted by a housing formed in the bearing having a polygonal shape (for example, rectangular or square) and intended to cooperate with the head of the fastener having a corresponding shape.

According to one embodiment, said assembly comprises three fixing zones between the bearing and the functional element. 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.

FIG. 1, already described, is a perspective view of a roller support fixed on a front bearing of a rotating electrical machine according to the state of the art;

Figure 2a, already described, is a sectional view of the attachment zone between the roller support and the front bearing of the rotating electrical machine and the corresponding mounting tool;

Figures 2b and 2c, already described, are sectional views illustrating solutions envisaged but not feasible to ensure the mounting of the roller support on the bearing in case of interference of the mounting tool with a stretcher of the vehicle;

Figure 3 is a longitudinal sectional view of an alternator according to the present invention; Figure 4 is a sectional view of the attachment zone between the roller support and the front bearing of an alternator according to the invention;

Figure 5 is a perspective view of the roller support attached to the front bearing of the alternator according to the present invention;

Figure 6 is a perspective view of the outside of the front bearing of the alternator having three fixing screws mounted according to the configuration of the present invention;

Figure 7 is a perspective view of the inside of the front bearing showing the anti-rotation means of the fixing screws; Figure 8 is a detailed view showing by transparency the cooperation between a fixing screw and a corresponding anti-rotation means;

Figure 9a is a perspective view illustrating an alternative embodiment for fixing an electrical module to the rear bearing of the rotating electrical machine according to the invention;

FIG. 9b is a detailed perspective view of an attachment zone between the electrical control module and the front bearing of the rotating electrical machine according to the invention. Identical, similar or similar elements retain the same reference from one figure to another.

In addition, a forward-to-back orientation corresponding to a left-to-right orientation is used in Fig. 3, so that a front member is located on the side of the pulley and a back member is on the opposite side.

FIG. 3 represents 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 into a space existing between two claws 29 adjacent to the other pole wheel, so that the claws 29 of the pole wheels 24, 25 are interlocked relative to one another.

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 rotor excitation winding 31.

A pulley 35 is fixed on the front end of the shaft 13. This pulley 35 belongs to a belt motion transmission device 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 manifold 41 to supply the winding of the rotor 12.

Moreover, the stator 16 comprises a body 43 in the form of a sheet-metal package provided with notches for mounting the phases of the stator 16. Each phase comprises at least one phase winding passing through the notches of the stator body 43 and forms, with all 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.

The phase windings are electrically connected to an electronic control module 50 visible in FIGS. 9a and 9b. This electronic control module 50 comprises a voltage rectifier bridge formed from rectifying elements, constituted for example by diodes or MOSFET type transistors.

As can be seen in FIGS. 6 and 7, the front bearing 17, all like the rear bearing 18, has a bottom 51 of transverse orientation provided with a central opening 52 allowing the passage of the shaft 13 and a flange 55 of annular shape of axial orientation from the outer periphery of the bottom 51 . The flange 55 may have a stepped internal diameter. The flanges 55 of the front bearing 17 and the rear bearing 18 are directed axially toward each other and has openings 69 for the passage of fastening tie rods ensuring the maintenance of the assembly.

As shown in FIG. 5, a functional element, here a roller support 58, is fixed on the front bearing 17 by means of fasteners 60 in the form of screws 60. Rollers 61 rotatably mounted about axes 62 are intended to come into contact with a belt, which cooperates with the pulley 35 mounted on the shaft 13.

As can be seen in Figure 4, each screw 60 is threaded from the inside to the outside of the internal volume 65 defined by the front bearings 17 and rear 18. Thus, during assembly, the free end 67 of the screw 60 passes through the thickness of the bottom 51 of the bearing via a column 68 coming from the bottom of the bearing 51, then the thickness of the roller support 58 and more precisely of a fixing lug 70 of said roller support 58, in such a way that the screw head 77 is on the side of the inner face of the bottom 51 of the bearing. In other words, the heads of the screws 60 are located inside the internal volume 65. It is specified that the column 68 is constituted by a projecting annular wall defining an opening for the passage of the corresponding screw 60.

A nut 72 is tightened on the free end 67 threaded of the screw 60 located outside the internal volume 65 of the electric machine. The tightening of the nut 72 is effected by means of a mounting tool 74. Because of the possibility of reducing the length of the column 68, such a configuration makes it possible to avoid the problem of interference between the tool mounting 74 and the stretcher of the vehicle body in the case of a compact engine configuration under the hood. Preferably, the screw 60 is fitted, for example by means of a knurled section 73 in the hole of the column 68.

In addition, anti-rotation means 76 is preferably provided for each screw 60 allowing in particular the corresponding screw 60 not to rotate during the tightening of the nut 72. As is illustrated in Figures 7 and 8, the anti-rotation means 76 may be constituted by a hollow rectangular shape or square, formed in the inner face of the bottom 51 of the bearing 17 and intended to cooperate with a screw head 77 of corresponding shape.

For example, it is possible to use three fixing zones, and therefore three screws 60, to ensure the attachment between the roller support 58 and the front bearing 17, as shown in FIG. 5. The number of fixing zones can of course be be adapted according to the need of the application.

In the embodiment of FIGS. 9a and 9b, a similar screwing system is used to ensure the attachment of the electronic control module 50 to the rear bearing 18 of the machine 10.

Thus, during assembly, each screw 60 is inserted in a direction going from the inside to the outside of the machine, so that each free end 67 of the screw 60 passes firstly through a projecting lug 78 having a hole in it. external periphery of the flange 55 of the rear bearing 18 to then cooperate with a tapping 79 formed in the body 80 of the electronic control module 50. Following assembly, the head of the screw 60 is located on the side of the inner face of the ear 78 of the bearing 18 turned towards the internal volume 65 of the machine 10.

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.

In addition, the various features, variations, and / or embodiments of the present invention may be associated with each other in various combinations, to the extent that they are not incompatible or exclusive of each other.

Claims

1. Motor vehicle assembly comprising:

a rotary electric machine (10) provided with a first bearing (17) and a second bearing (18) delimiting an internal volume (65),

a functional element (50, 58),

at least one fastener (60) passing through a portion (51, 78) of one of the bearings (17, 18) having an internal face turned towards the internal volume (65) and an external face turned towards the opposite side,

characterized in that said fixing member (60) comprises a head (77) located on the side of the inner face of the portion of the bearing (51, 78).

2. An assembly according to claim 1, characterized in that the functional element is a roller support (58) intended to cooperate with a belt, which cooperates with a pulley (35) mounted on a shaft (13) of the electric machine rotating (10).

3. An assembly according to claim 2, characterized in that said bearing portion being constituted by a bearing base (51), the fastening member (60) through a thickness of the roller support (58) and a thickness of said bottom bearing (51).

4. An assembly according to claim 3, characterized in that the head (77) of the fastener (60) is located inside the internal volume (65) of the rotating electrical machine (10).

5. An assembly according to claim 3 or 4, characterized in that the fastener (60) passes through the thickness of the bearing base (51) via a perforated column (68).

6. An assembly according to any one of claims 3 to 5, characterized in that a nut (72) is screwed onto a free end (67) threaded of the fastener (60) located outside the volume internal (65) of the rotating electrical machine (10).

7. The assembly of claim 1, characterized in that the functional element is an electronic control module (50).

8. The assembly of claim 7, characterized in that said bearing portion being constituted by a perforated lug (78) from an outer periphery of a flange (55) of the bearing, the fastener (60) through said lug (78) and cooperates with a tapping (79) formed in a body (80) of the electronic control module (50).

9. An assembly according to any one of claims 1 to 8, characterized in that the fastener (60) is fitted into a hole in the bearing portion (51, 78).

10. The assembly of claim 9, characterized in that the fixing member (60) is fitted by means of a knurled section (73).

1 1. Assembly according to any one of claims 1 to 10, characterized in that it comprises an anti-rotation means (76) of the fixing member (60).

12. The assembly of claim 1 1, characterized in that the anti-rotation means (76) is constituted by a housing formed in the bearing having a polygonal shape and intended to cooperate with the head (77) of the organ. fastener (60) having a corresponding shape.

13. An assembly according to any one of claims 1 to 12, characterized in that it comprises three fixing zones between the bearing and the functional element (50, 58).