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, a sleeve (3) embedded in a housing of said casing, a plurality of coils having a projecting part, said coils being connected to a plurality of connectors (20) supported by a base (21), said motor further comprising a sealing 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 having a mounting orifice (14) through which it fits said projecting part, said ring being in two separate semi-circular parts (11a, 11b) held against each other by said gasket receiving them in fitting, one of said parts (11a) being provided with fitting means (22) receiving said base in fitting.The invention also relates to a method of mounting a sealing device of such an engine (1). Figure 2.

Description

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

[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 coils being connected to a plurality of connectors supported by a base, said motor further comprising an annular sealing device having 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 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 may prove to be complex, the mounting hole having to be temporarily enlarged to allow the said device to be fitted onto the protruding part.

[0005] Furthermore, the connectors supported by the base usually have a certain flexibility, which makes it difficult to correctly position them in their nominal position and can cause problems when mounting the rotor in the stator provided with the sealing device. Such problems can also occur when mounting a bearing carrier plate.

[0006] The invention aims to overcome these drawbacks.

[0007] 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 coils being connected to a plurality of connectors supported by a base, said motor further comprising an annular sealing device having 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 carry out its cooling, said engine further having the following characteristics: - said ring is presented in two separate semi-circular parts held against each other by said seal receiving them in interlocking, so that said ring may have been put into an enlarged configuration by spacing said parts apart from each other in order to allow an enlargement of said mounting orifice in order to ensure the mounting of said sealing device, - one of said parts is provided with fitting means resulting from molding, said fitting means receiving in fitting said base so as to index its position in said engine.

[0008] 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.

[0009] With such an arrangement, the fitting of the sealing device is facilitated by the possibility of putting the ring in an enlarged configuration.

[0010] It will also be noted that the elastic nature of the seal allows it to stretch during assembly of the sealing device and then, after its retraction, to ensure that said device is held in place once assembled.

[0011] Furthermore, the use of a ring in two separate parts means that it does not have to be deformed when mounting the sealing device, which is an advantage when the plastic material constituting said ring is not very flexible, which is usually the case with plastic materials intended to be exposed to the high temperatures that can be found in engines.

[0012] As for the connectors supported by the base, they are placed in their nominal position by the fitting means receiving said base, which facilitates the mounting of the rotor or a bearing carrier plate.

[0013] According to one embodiment, the base is in the form of a perforated plate receiving the connectors, said base extending in axial view along an arc of a circle, the fitting means receiving the ends of said base in a fitting manner.

[0014] According to the embodiment shown, the ends of the ring parts are arranged so that two contiguous ends fit into each other when the ring is in the non-expanded configuration, so as to allow good positioning of said parts relative to each other.

[0015] According to one embodiment, the sealing gasket is made of rubber.

[0016] 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.

[0017] According to one embodiment, the discharge orifices are distributed circularly in a regular manner, so as to ensure uniform cooling of the projecting part.

[0018] According to one embodiment, the number of discharge orifices is between 6 and 20, so as to ensure uniform cooling of the projecting part.

[0019] According to a second aspect, the invention proposes a method of mounting a sealing device for a motor, said motor comprising a stator comprising a plurality of coils having a projecting part, said coils connecting to a plurality of connectors supported by a base, said device comprising an annular sealing gasket based on elastomeric material and a ring of molded plastic material fitted inside said gasket so that said device defines a mounting orifice, said ring being in two separate semi-circular parts held against each other by said gasket receiving them in fitting, one of said parts being provided with fitting means, 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 parts are held against each other, to a mounting configuration where said seal is stretched and where said parts are separated from each other in order to enlarge said mounting hole, - 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 mounting and maintenance of said device and the fitting of said base in said fitting means.

[0020] 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 partial schematic representation in perspective of the motor shown in [Fig.l], the base supporting the connectors being fitted into the fitting means of the ring of the sealing device.

[0021] 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, 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 protruding axially from said axial end and inscribed in axial view in a circle, said coils being connected to a plurality of connectors 20 supported by a base 21, said motor further comprising an annular sealing device 8 having a mounting orifice 14 through which it fits said projecting part, said device comprising: - an annular seal 9 based on elastomer material, said seal 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 engine further having the following characteristics: - said ring is in two separate semi-circular parts 11a, 11b held against each other by said seal receiving them in an interlocking manner, so that said ring can be put into an enlarged configuration by moving said parts apart from each other in order to allow an enlargement of said mounting orifice in order to ensure the mounting of said sealing device, - one of said parts 11a is provided with interlocking means 22 resulting from molding, said interlocking means receiving said base in interlocking manner so as to index its position in said engine.

[0022] According to one embodiment, the base 21 is made of molded plastic material.

[0023] According to the embodiment shown, the base 21 is in the form of a perforated plate receiving the connectors 20, said base extending in axial view along an arc of a circle, the fitting means 22 receiving in fitting the ends 23 of said base.

[0024] In a manner not shown, the ends of the ring parts 11a, 11b may be arranged so that two contiguous ends fit into each other when the ring 11 is in the non-expanded configuration.

[0025] According to one embodiment, the sealing gasket 9 is made of rubber.

[0026] According to one embodiment, the ring 11 is made of polyamide reinforced with glass fibers.

[0027] According to an embodiment not shown, the evacuation orifices 12 are distributed circum- cularly on a regular basis.

[0028] According to an embodiment not shown, the number of discharge orifices 12 is between 6 and 20.

[0029] Finally, a method is described for mounting a sealing device 8 of a motor 1, said motor comprising a stator comprising a plurality of coils 6 having a projecting part 7, said coils being connected to a plurality of connectors 20 supported by a base 21, 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 so that said device defines a mounting orifice 14, said ring being in two separate semi-circular parts 11a, 11b held against each other by said gasket receiving them in fitting, one of said parts 11a being provided with fitting means 22, 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 parts are held against each other, to a mounting configuration where said seal is stretched and where said parts are separated from each other in order to enlarge said mounting hole, - 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 mounting and maintenance of said device and the fitting of said base in said fitting means.

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 coils being connected to a plurality of connectors (20) supported by a base (21), said motor further comprising an annular sealing device (8) having 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 the oil to be discharged from said cavity towards said projecting part to cool it, said motor being characterized in that: - said ring is in two disjointed semi-circular parts (11a, 11b) held against each other by said seal receiving them in fitting, so that said ring can have been put in an enlarged configuration by spacing said parts from each other in order to allow an enlargement of said mounting orifice in order to ensure the mounting of said sealing device, - one of said parts (11a) is provided with fitting means (22) resulting from molding, said fitting means receiving in fitting said base so as to index its position in said motor.

2. Motor according to claim 1, characterized in that the base (21) is in the form of a perforated plate receiving the connectors (20), said base extending in axial view along an arc of a circle, the fitting means (22) receiving in fitting the ends (23) of said base.

3. Motor (1) according to any one of claims 1 or 2, characterized in that the ends of the ring parts (11a, 11b) are arranged so that two contiguous ends fit into each other when the ring (11) is in the non-expanded configuration.

4. Motor (1) according to any one of claims 1 to 3, characterized in that the sealing gasket (9) is made of rubber.

5. Motor (1) according to any one of claims 1 to 4, characterized in that the ring (11) is made of polyamide reinforced with glass fibers.

6. Motor (1) according to any one of claims 1 to 5, characterized in that the discharge orifices (12) are distributed circularly in a regular manner.

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

8. A method of mounting a sealing device (8) of a motor (1) according to any one of claims 1 to 7, said motor comprising a stator comprising a plurality of coils (6) having a projecting portion (7), said coils connecting to a plurality of connectors (20) supported by a base (21), 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 so that said device defines a mounting orifice (14), said ring being in two separate semi-circular parts (11a, 11b) held against each other by said gasket receiving them in fitting, one of said parts (11a) being provided with fitting means (22), 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 parts are held against each other, to a mounting configuration where said seal is stretched and where said parts are separated from each other in order to enlarge said mounting hole, - 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 mounting and maintenance of said device and the fitting of said base in said fitting means.

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