FR3086124A1 - ROTARY ELECTRIC MACHINE ASSEMBLY AND REDUCING ELEMENT AVOIDING INFILTRATION IN THE ROTARY ELECTRIC MACHINE - Google Patents

Abstract

The invention relates mainly to an assembly for a motor vehicle, comprising: - a rotary electric machine (10) comprising a bearing (15) provided with a receiving housing (17) of a bearing (19) ensuring rotation guidance of the shaft (13), - a reducing element (22) provided with a casing (48), characterized in that: - the bearing (15) is arranged to close the casing (48) so as to delimit a chamber (47) subjected to a spraying of coolant and / or lubrication, - the rotary electric machine (10) comprising a seal (64) interposed radially between the shaft (13) of the rotary electric machine (10 ) and the bearing (15), - the seal (64) being arranged to prevent the coolant and / or lubrication liquid from passing from the chamber (47) towards the interior of the rotary electric machine (10) .

Description

ROTATING ELECTRIC MACHINE ASSEMBLY AND REDUCING ELEMENT AVOIDING INFILTRATION IN THE ROTATING ELECTRIC MACHINE

The present invention relates to an assembly with a rotating electrical machine and a reducing element preventing infiltration into the rotating electrical machine. The invention finds a particularly advantageous, but not exclusive, application with reversible high power electric machines which can operate in alternator mode and in motor mode coupled with a reducing element.

In a manner known per se, rotary electrical machines comprise a stator and a rotor secured to a shaft. The stator is mounted in a casing configured to rotate the shaft on bearings by means of bearings.

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

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 a winding. The winding is obtained for example from a continuous wire covered with enamel or from conductive elements in the form of pins linked together by welding. The winding comprises phase windings connected in a star or a triangle, the outputs of which are connected to an electronic control module.

In certain types of motor vehicle traction chains ensuring the transmission of mechanical power from the heat engine to the wheels of the vehicle, a high power reversible rotating electric machine can be coupled to a reducing element. The reducing element may take the form of a vehicle gearbox or of a reduction gear mounted on a train of the vehicle and mechanically connected to the rotating electric machine.

According to certain configurations, the front bearing of the electric machine acts as a cover to close a chamber delimited by a casing of the reducing element and containing a connection interface between the shaft of the electric machine and a shaft of the reducing element .

This chamber being subjected to projections of lubricating liquid, such as oil or grease, used to ensure lubrication of the components of the reducing element, there is a risk of observing intrusions of foreign body of the liquid type. (oil, grease ...) or solid (iron filings ...) inside the electric machine. Liquid intrusions have the direct consequence of damaging the electronic control module, while solid intrusions are likely to damage the mechanical part of the electric machine, in particular the bearings and the air gap.

The present invention aims to effectively remedy these drawbacks by proposing an assembly for a motor vehicle, comprising:

- a rotating electric machine comprising:

- a tree,

- a rotor mounted on the shaft,

- a stator, in particular surrounding the rotor,

- a bearing comprising a housing for receiving a bearing ensuring rotational guidance of the shaft,

- a reducing element provided with a casing, characterized in that:

the bearing is arranged to close a chamber delimited by the casing, said chamber being subjected to a projection of coolant and / or lubrication,

- the rotary electric machine comprising a seal interposed radially between the shaft of the rotary electric machine and the bearing,

- the seal being arranged to prevent the coolant and / or lubrication liquid from passing from the chamber towards the interior of the rotary electrical machine.

According to one embodiment, the seal has an annular shape.

According to one embodiment, the seal is a lip seal.

According to one embodiment, the lip seal has an external portion bearing against an annular bearing of the bearing and an internal lip in contact with the shaft.

According to one embodiment, from a junction with the external portion, the internal lip extends in the direction of the chamber.

According to one embodiment, the chamber contains a connection interface between the shaft of the rotary electric machine and a shaft of the reducing element.

According to one embodiment, the connection interface is devoid of a seal.

According to one embodiment, an additional seal is mounted between the casing of the reducing element and the bearing of the rotary electrical machine.

According to one embodiment, the reducing element is a motor vehicle gearbox.

According to one embodiment, the reducing element is a reduction gear mounted on a train of the vehicle and coupled to the rotary electric machine.

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 perspective view of the rotary electrical machine according to the present invention;

Figure 2 is a longitudinal sectional view of the rotary electrical machine according to the invention;

Figure 3 is a perspective view of a rotary electrical machine coupled to a reducing element to form an assembly according to the invention;

Figure 4 is a detailed sectional view of the lip seal for sealing between the reducing element and the rotary electrical machine of the assembly according to the invention.

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

In the following description, we consider an orientation from front to rear, an orientation going from left to right in Figures 1 and 2. Thus, by a front element is meant an element located on the side of the front bearing 19 and by rear element an element situated on the opposite side, that is to say on the side of the electronic control module 34.

Figures 1 and 2 show a rotary electric machine 10 comprising a polyphase stator 11 surrounding a rotor 12 mounted on a shaft 13 of axis X corresponding to the axis of the electric machine 10. The stator 11 surrounds the rotor 12 with the presence of an air gap between the internal periphery of the stator 11 and the external periphery of the rotor 12. The stator 11 is mounted in a casing 14 comprising a front bearing 15 and a rear bearing 16. The front bearing 15 and the rear bearing 16 each have a receiving housing 17, 18 of a corresponding bearing 19, 20 which guides the shaft 13 in rotation.

This electric machine 10 is intended to be coupled to a speed reducing element 22. The reducing element 22 may take the form of a motor vehicle gearbox or a reduction gear mounted on a train of the vehicle and coupled to the rotating electric machine 10.

The electric machine 10 is able to operate in an alternator mode in particular to supply energy to the battery and to the on-board network of the vehicle, and in an engine mode, to ensure the starting of the heat engine of the vehicle, and if necessary to participate in the traction of the vehicle alone or in combination with the engine. The power of the machine could for example be between 15kW and 50kW.

More specifically, as visible in FIG. 2, the rotor 12 comprises a body 24 in the form of a pack of sheets. Permanent magnets 25 are implanted in cavities 26 of the body 24. The magnets 25 may be made of rare earth or ferrite depending on the applications and the desired power of the electric machine 10.

In addition, the rotor 12 comprises two flanges 28, 29 each pressed against an axial end face of the rotor 12. These flanges 28, 29 provide an axial retention of the magnets 25 and also serve to balance the rotor 12.

Furthermore, the stator 11 comprises a body 31 constituted by a pack of sheets as well as a coil 32. The body 31 is formed by a stack of sheets of sheets maintained in the form of a pack by means of a suitable fixing system, such as rivets.

The stator body 11 is provided with teeth delimiting notches for mounting the winding 32. The winding 32 comprises a set of phase windings passing through the notches and forming buns extending projecting on either side of the body stator 11. The winding 32 is obtained here from conductive elements in the form of pins connected together for example by welding. The winding 32 comprises phase windings of the double three-phase type connected in star and / or in triangle. Phase outputs are intended to be connected to an electronic control module 34.

The electronic control module 34 comprises a heat sink 35 on which are fixed in particular power modules 36, for example by screwing. These power modules 36 incorporate switches in known manner, for example taking the form of MOS type transistors, making it possible to control the phases of the rotary electric machine 10 in motor mode or in alternator mode. The switching of these transistors is controlled by a control unit. The electronic control module 34 is mounted flat, via the heat sink 35, against the rear face of the rear bearing 16.

Advantageously, the electric machine 10 comprises a cooling circuit 38 having an inlet 39 and an outlet 40 for coolant, such as a water or oil-based liquid. The cooling circuit 38 has a cooling chamber 41 formed in the mass of the heat sink 35 and a cooling chamber 42 surrounding the stator 11.

The cooling chamber 42 may be delimited by the external periphery of an annular wall of the front bearing 15 and the internal periphery of an annular wall of the rear bearing 16. This cooling chamber 42 is closed at its axial ends via two seals 46 toroidal type. The stator 11 is mounted hooped inside the front bearing 15 so as to establish intimate contact between the external periphery of the stator body 31 and the internal periphery of the side wall of the front bearing 15.

According to certain configurations, the front bearing 15 is arranged to close a chamber 47 delimited by a casing 48 of the reducing element 22, as shown in FIG. 3. This chamber 47 is subjected to a projection of lubricating liquid and / or cooling the reducing element 22, such as oil or grease.

In this case, the casing 48 includes a tubular portion 49 authorizing the passage of a shaft 50 of the reducing element 22. The tubular portion 49 is extended by a transverse wall 51. An annular skirt 52 comes from the external periphery of the transverse wall 51.

The chamber 47 delimited by the transverse wall 51 and the skirt 52 of the casing 48 is closed at an axial end by the front bearing 15. This chamber 47 contains a connection interface 54 between the shaft 13 of the electric machine 10 and the shaft 50 of the reducing element 22. For this purpose, the shaft 50 has a grooved end 55 cooperating with a grooved internal portion of complementary shape of a sleeve 56. The connection interface 54 further comprises an epicyclic train 57 connected on the one hand to the sleeve 56 and on the other hand to the shaft 50 of the reducing element 22. The connection interface 54 has no seal.

Furthermore, the front bearing 15 has a transverse wall 59 comprising the central housing 17 for receiving the bearing 19 and an annular skirt 60 coming from the external periphery of the transverse wall 59. The annular skirt 60 constitutes the internal wall of the cooling 42.

A seal 61, in particular of the O-ring type, is mounted between the casing 48 of the reducing element 22 and the front bearing 15 of the electric machine 10. The seal 61 is for example interposed radially between an annular flange 62 of the front bearing 15 and an internal periphery of the skirt 52 of the casing 48. The flange 62 and the skirt 60 of the front bearing 15 extend on either side of the wall 59 in two opposite axial directions one by compared to each other. The rim 62 is inserted inside the skirt 52 of the casing 48, so that an external portion of the front bearing 15 comes into contact with an axial end of the casing 48 of the reducing element 22.

In addition, a seal 64 is interposed radially between the shaft 13 of the electric machine 10 and the front bearing 15. This seal 64 is arranged to prevent the coolant and / or lubrication of the reducing element 22 to pass from the chamber 47 towards the interior of the electric machine 10.

This seal 64, generally of annular shape, is preferably a lip seal. As can be seen in FIG. 4, the lip seal 64 has an external portion 65 bearing against an annular bearing of the front bearing 15 and an internal lip 67 in contact against the shaft 13. From a junction with the outer portion 65, the lip 67 extends in the direction of the end 55 of the shaft 13 provided with grooves. In other words, the lip 67 extends in the direction of the chamber 47 and not towards the interior of the electric machine 10.

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 (10)

1. Motor vehicle assembly, comprising: - a rotary electric machine (10) comprising: - a tree (13), - a rotor (12) mounted on the shaft (13), - a stator (11), in particular surrounding the rotor (12), - a bearing (15) comprising a housing (17) for receiving a bearing (19) ensuring rotational guidance of the shaft (13), - a reducing element (22) provided with a casing (48), characterized in that: the bearing (15) is arranged to close a chamber (47) delimited by the casing (48), said chamber (47) being subjected to a spraying of coolant and / or lubrication, the rotary electric machine (10) comprising a seal (64) interposed radially between the shaft (13) of the rotary electric machine (10) and the bearing (15), - The seal (64) being arranged to prevent the coolant and / or lubrication from passing from the chamber (47) towards the interior of the rotary electric machine (10). 2. Assembly according to claim 1, characterized in that the seal (64) has an annular shape. 3. Assembly according to claim 1 or 2, characterized in that the seal (64) is a lip seal. 4. Assembly according to claim 3, characterized in that the lip seal (64) comprises an external portion (65) bearing against an annular bearing of the bearing (15) and an internal lip (67) in contact against the shaft (13). 5. Assembly according to claim 4, characterized in that from a junction with the external portion (67), the internal lip (67) extends in the direction of the chamber (47). 6. An assembly according to any one of claims 1 to 5, characterized in that the chamber (47) contains a connection interface (54) between the shaft (13) of the rotary electric machine (10) and a shaft ( 50) of the reducing element (22). 7. The assembly of claim 6, characterized in that the connecting interface (54) is devoid of seal. 5 8. An assembly according to any one of claims 1 to 7, characterized in that an additional seal (61) is mounted between the housing (48) of the reducing element (22) and the bearing (15) of the rotating electric machine (10). 9. An assembly according to any one of claims 1 to 8, characterized in ίο that the reducing element (22) is a motor vehicle gearbox. 10. An assembly according to any one of claims 1 to 8, characterized in that the reducing element (22) is a reduction gear mounted on a train of the vehicle and coupled to the rotary electric machine (10).