ELECTRIC MOTOR FOR PROPULSION OF A MOTOR VEHICLE AND METHOD FOR MOUNTING A SEALING DEVICE FOR SUCH A MOTOR

Abstract

The invention relates to an electric motor (1) for propulsion of a motor vehicle, said motor comprising a casing (2), a sleeve (3) embedded in a housing of said casing, a plurality of coils (6) mounted inside said sleeve and having a projecting part (7), a sealing device (8) comprising an annular sealing gasket (9) based on elastomer material and a ring (11) made of molded plastic material fitted inside said gasket, said device defining a mounting orifice (14) through which it fits said projecting part, said ring having an axial slot to allow a temporary enlargement of said mounting orifice in order to ensure the mounting of said sealing device. The invention also relates to a method for mounting a sealing device (8) of such a motor (1). Figure 1

Description

Title of the invention: ELECTRIC MOTOR FOR PROPULSION OF A MOTOR VEHICLE AND ASSEMBLY METHOD OF A SEALING DEVICE FOR SUCH AN ENGINE

[0001] The invention relates to an electric motor for propelling a motor vehicle and a method for mounting a sealing device for such a motor.

[0002] It is known to produce an electric motor for propelling a motor vehicle, said motor comprising a casing defining a cylindrical housing, said motor further comprising a rotor, provided with a plurality of permanent magnets, and a stator comprising: - a cylindrical steel sleeve embedded in said housing, said sleeve being provided with axial channels intended to be supplied with pressurized oil, said sleeve having an axial end where said channels open, - and a plurality of coils of conductive wire intended to be supplied with electric current, said coils being mounted inside said sleeve, said plurality of coils having a projecting part axially projecting from said axial end and falling in axial view within a circle, said motor further comprising an annular sealing device defining a mounting orifice through which it fits said projecting part, said device comprising: - an annular seal based on elastomeric material, said seal bearing against said casing and against said axial end so as to define a circular cavity, said channels opening into said cavity so that said cavity can receive the oil from said channels, - and a ring made of molded plastic material fitted inside said seal, said ring being provided with a plurality of discharge orifices distributed circularly and being positioned opposite a plurality of corresponding discharge orifices provided in said seal opposite said cavity and said projecting part, so as to allow evacuation of the oil from said cavity towards said projecting part to effect its cooling.

[0003] It will be noted here that the cooling of the projecting part allows, by thermal conduction, an overall cooling of the coils.

[0004] With such an arrangement, the mounting of the sealing device can prove complex, the mounting hole having to be temporarily enlarged to allow the said device to be fitted onto the projecting part.

[0005] The invention aims to overcome this drawback.

[0006] To this end, and according to a first aspect, the invention proposes an electric motor for propulsion of a motor vehicle, said motor comprising a casing defining a cylindrical housing, said motor further comprising a rotor, provided with a plurality of permanent magnets, and a stator comprising: - a cylindrical steel sleeve embedded in said housing, said sleeve being provided with axial channels intended to be supplied with pressurized oil, said sleeve having an axial end where said channels open, - and a plurality of coils of conductive wire intended to be supplied with electric current, said coils being mounted inside said sleeve, said plurality of coils having a projecting part axially projecting from said axial end and falling in axial view within a circle, said motor further comprising an annular sealing device defining a mounting orifice through which it fits said projecting part, said device comprising: - an annular seal based on elastomer material, said seal bearing against said casing and against said axial end so as to define a circular cavity, said channels opening into said cavity so that said cavity can receive the oil from said channels, - and a ring of molded plastic material fitted inside said seal, said ring being provided with a plurality of discharge orifices distributed circularly and being positioned opposite a plurality of corresponding discharge orifices provided in said seal opposite said cavity and said projecting part, so as to allow evacuation of the oil from said cavity towards said projecting part to effect its cooling, said ring having an axial slot to allow temporary enlargement of said mounting orifice in order to ensure the mounting of said sealing device.

[0007] It is specified here that, throughout the description, the term “axially” is taken with reference to the axis of rotation of the motor (reference X in the figures), corresponding in this case to the axis of symmetry of the sleeve.

[0008] The enlargement of the mounting hole allowed the projecting part to be fitted with the sealing device.

[0009] The elastic nature of the seal allows it to stretch during assembly of the sealing device and then, after its retraction, to ensure the maintenance of said device once assembled.

[0010] According to one embodiment, the sealing gasket is made of rubber.

[0011] According to one embodiment, the ring is made of polyamide reinforced with glass fibers, the choice of such a plastic material allowing said ring to have good resistance to high temperatures, for example of the order of 200°C.

[0012] According to one embodiment, the discharge orifices are distributed circularly in a regular manner, so as to ensure uniform cooling of the projecting part.

[0013] According to one embodiment, the number of discharge orifices is between 6 and 20, so as to ensure uniform cooling of the projecting part.

[0014] According to a second aspect, the invention proposes a method for mounting a sealing device for such a motor, said motor comprising a stator comprising a plurality of coils having a projecting part, said device comprising an annular seal based on elastomeric material and a ring made of molded plastic material fitted inside said seal, said device defining a mounting orifice, said ring having an axial slot, said method comprising the following steps: - deforming under stress said device so as to make it pass from a nominal configuration, where said seal is unstretched and where said slot is closed, to a mounting configuration where said seal is stretched and where said slot is actuated in opening in order to enlarge said mounting orifice, - fit said protruding part with said device placed in the mounting configuration, - release the constraint so as to achieve, under the effect of an elastic release of said joint, the assembly and maintenance of said device.

[0015] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: [Fig.l] is a partial schematic representation in axial section of a motor according to one embodiment, [Fig.2] is a schematic representation in exploded perspective of the sealing device of the engine shown in [Fig.l], the ring of said device being shown with its slot substantially closed.

[0016] We will now describe, with reference to the figures, an electric motor 1 for propelling a motor vehicle, said motor comprising a casing 2 defining a cylindrical housing, said motor further comprising a rotor, not shown, provided with a plurality of permanent magnets, and a stator comprising: - a cylindrical steel sleeve 3 embedded in said housing, said sleeve being provided with axial channels 4 intended to be supplied with pressurized oil, said sleeve having an axial end 5 where said channels open, - and a plurality of coils 6 of conductive wire intended to be supplied with electric current, said coils being mounted inside said sleeve, said plurality of coils having a projecting part 7 axially extending from said axial end and inscribed in axial view in a circle, said motor further comprising an annular sealing device 8 defining a mounting orifice 14 through which it fits said projecting part, said device comprising: - an annular sealing gasket 9 based on elastomer material, said gasket bearing against said casing and against said axial end so as to define a circular cavity 10, said channels opening into said cavity so that said cavity can receive the oil coming from said channels, - and a ring 11 made of molded plastic material fitted inside said seal, said ring being provided with a plurality of discharge orifices 12 distributed circularly and being positioned opposite a plurality of corresponding discharge orifices 13 provided in said seal opposite said cavity and said projecting part, so as to allow evacuation of the oil from said cavity towards said projecting part to carry out its cooling, said ring having an axial slot 17 to allow temporary enlargement of said mounting hole in order to ensure the mounting of said sealing device.

[0017] According to one embodiment, the sealing gasket 9 is made of rubber.

[0018] According to one embodiment, the ring 11 is made of polyamide reinforced with glass fibers.

[0019] According to an embodiment not shown, the discharge orifices 12 are distributed circularly in a regular manner.

[0020] According to an embodiment not shown, the number of discharge orifices 12 is between 6 and 20.

[0021] Finally, a method of mounting a sealing device 8 of such a motor 1 is described, said motor comprising a stator comprising a plurality of coils 6 having a projecting portion 7, said device comprising an annular sealing gasket 9 based on elastomer material and a ring 11 made of molded plastic material fitted inside said gasket, said device defining a mounting orifice 14, said ring having an axial slot 17, said method comprising the following steps: - deforming said device under stress so as to make it pass from a nominal configuration, where said gasket is unstretched and where said slot is closed, to a mounting configuration where said gasket is stretched and where said slot is actuated to open in order to enlarge said mounting orifice, - fitting said projecting portion by said device placed in the nominal configuration, ... assembly, release the constraint so as to achieve, under the effect of an elastic release of said joint, the assembly and maintenance of said device.

Claims

Claims

1. Electric motor (1) for propelling a motor vehicle, said motor comprising a casing (2) defining a cylindrical housing, said motor further comprising a rotor, provided with a plurality of permanent magnets, and a stator comprising: - a cylindrical steel sleeve (3) embedded in said housing, said sleeve being provided with axial channels (4) intended to be supplied with pressurized oil, said sleeve having an axial end (5) where said channels open, - and a plurality of coils (6) of conductive wire intended to be supplied with electric current, said coils being mounted inside said sleeve, said plurality of coils having a projecting part (7) axially extending from said axial end and falling in axial view within a circle, said motor further comprising an annular sealing device (8) defining a mounting orifice (14) through which it fits said projecting part, said device comprising: - an annular sealing gasket (9) based on elastomer material, said gasket bearing against said casing and against said axial end so as to define a circular cavity (10), said channels opening into said cavity so that said cavity can receive the oil coming from said channels, - and a ring (11) made of molded plastic material fitted inside said seal, said ring being provided with a plurality of discharge orifices (12) distributed circularly and being positioned opposite a plurality of corresponding discharge orifices (13) provided in said seal opposite said cavity and said projecting part, so as to allow evacuation of the oil from said cavity towards said projecting part to carry out its cooling, said motor being characterized in that said ring has a slot (17) axial to allow temporary enlargement of said mounting hole to ensure mounting of said sealing device.

2. Engine (1) according to claim 1, characterized in that the sealing gasket (9) is made of rubber.

3. Motor (1) according to any one of claims 1 or 2, characterized in that the ring (11) is made of polyamide reinforced with glass fibers.

4. Motor (1) according to any one of claims 1 to 3, characterized in that the discharge orifices (12) are distributed circularly in a regular manner.

5. Motor (1) according to any one of claims 1 to 4, characterized in that the number of discharge orifices (12) is between 6 and 20.

6. A method of mounting a sealing device (8) of a motor (1) according to any one of claims 1 to 5, said motor comprising a stator comprising a plurality of coils (6) having a projecting portion (7), said device comprising an annular sealing gasket (9) based on elastomeric material and a ring (11) made of molded plastic material fitted inside said gasket, said device defining a mounting orifice (14), said ring having an axial slot (17), said method comprising the following steps: - deforming said device under stress so as to make it pass from a nominal configuration, where said gasket is unstretched and where said slot is closed, to a mounting configuration where said gasket is stretched and where said slot is actuated to open in order to enlarge said mounting orifice, - fitting said projecting portion by said device placed in mounting configuration,- release the constraint so as to achieve, under the effect of an elastic release of said joint, the assembly and maintenance of said device.,

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