An arrangement comprising a housing for a stator of a rotating electrical machine and a means for guiding a cooling fluid.

Abstract

An arrangement comprising a housing for a stator of a rotating electrical machine and a means for guiding a cooling fluid. An arrangement (10) comprising a housing (1) for a stator of a rotating electrical machine, the housing (1) extending along a given axis (X) between a first plane (P1) and a second plane (P2), the first plane (P1) and the second plane (P2) being perpendicular to the given axis (X), the housing (1) comprising: - a cylindrical bore (11) along the given axis (X) for containing the stator, and - a slot (12) substantially in the form of a cylindrical tube extending along the given axis (X), the cylindrical tube being cut into the housing (1) between the first plane (P1) and a third plane (P3) located between the first plane (P1) and the second plane (P2), the third plane (P3) being perpendicular to the given axis (X). The arrangement (10) further comprises a water guide (2) inserted in the slot (12) so as to extend between the first plane (P1) and the third plane (P3).Figure for the abridged version: [Fig.6].

Description

Title of the invention: Arrangement comprising a housing for a stator of a rotating electrical machine and a means for guiding a cooling fluid.

[0001] The invention relates to an arrangement comprising a housing for a stator of a rotating electrical machine. The invention further relates to a vehicle equipped with such an arrangement.

[0002] A stator is a component of an electrical machine consisting of a set of welded or glued metal sheets and copper wires that allow the passage of a high-voltage, high-intensity electric current through the metal sheets. However, the current causes the assembly to heat up due to the Joule effect. It is therefore necessary to dissipate the heat generated on the stator to ensure its proper long-term operation.

[0003] Cooling solutions exist. For example, for housings made using the "LPDC" (Low Pressure Die Cast) method, one solution may be to include a cavity of a particular shape within the housing for the circulation of a cooling fluid. For housings made using the "HPDC" (High Pressure Die Cast) method, such a cavity may be created between two housings. Such a cavity may also be obtained by means of an open core in a housing made using the "HPDC" method, with specific shapes of the cavity dedicated to water circulation being ensured by an added water guide.

[0004] However, existing cooling solutions have drawbacks. In particular, they do not allow for optimized stator cooling, notably by specifically guiding the cooling fluid within the housing to improve heat exchange.

[0005] The object of the invention is to provide an arrangement comprising a housing for a stator of a rotating electrical machine that overcomes the above drawbacks and improves upon prior art arrangements comprising a housing for a stator of a rotating electrical machine. In particular, the invention makes it possible to implement an arrangement that is simple and reliable and that improves the efficiency of stator cooling.

[0006] To this end, the arrangement according to the invention comprises a housing for a stator of a rotating electrical machine, the housing extending along a given axis between a first plane and a second plane, the first plane and the second plane being perpendicular to the given axis, the housing comprising: - a cylindrical bore along the given axis intended to house the stator, and - a slot substantially in the shape of a cylindrical tube extending along the given axis, the cylindrical tube being cut into the casing between the first plane and a third plane situated between the first and second planes, the third planes being perpendicular to the given axis, the arrangement further comprising a water guide inserted in the slot so as to extend between the first and third planes, and in that the water guide comprises - a first ring, in particular an end ring connected to a second ring, in particular a ring of opposite end, by at least one connecting wall or by a helical wall, the first and second end rings being coaxial to the given axis, - each ring and / or each connecting wall and / or the helical wall extend between the outer and inner surfaces of the cylindrical tube formed by the slot to define a path of a cooling fluid circulating in the slot between the first plane and the third plane and in contact with the outer and inner surfaces of the cylindrical tube.

[0007] The arrangement that is the subject of the invention may further comprise the following features taken individually or in combination with each other: - the path of a cooling fluid is defined by the water guide in the form of a coil making back and forth movements between the connecting walls parallel to the given axis between the first plane and the third plane, or in the form of a spiral winding around the given axis along the turns of the helical wall and extending between the first plane and the third plane; - it comprises several connecting walls distributed at equal angular intervals around the given axis; - at least one connecting wall is substantially straight and parallel to the given axis; - the connecting walls, in pairs, together with the outer and inner surfaces of the slot, define a heat exchange chamber - each connecting wall includes at least one through-opening for the circulation of the cooling fluid through the connecting wall to the heat exchange chamber directly adjacent to it, - the openings in successive connecting walls are alternately arranged at either end of the water guide, - the housing comprises a first orifice and a second orifice passing through the housing between an outer surface of the housing and the outer surface of the tube formed by the slot, - the first and second orifices are respectively in fluidic contact with two adjacent heat exchange chambers, the heat exchange chambers and the openings allowing a serpentine flow of the cooling fluid, the first and second orifices being intended to be connected to ducts of a cooling system, - the helical wall defines a single spiral-shaped heat exchange chamber comprising several turns, in particular between 2 and 5 turns, the chamber having a cross-section that varies between one of the end rings and the turn directly adjacent to it, in particular with a cross-section that increases in size near one of the end rings of the water guide, and in particular with a cross-section that decreases in size near the other end, depending on the direction of flow of the cooling fluid, - the helical wall comprises at least two parallel turns, - the turns of the helical wall are connected to each other by stiffening bridges parallel to the given axis, each stiffening bridge extending over at least a part of the height of the helical wall such that the cooling fluid is able to circulate between at least one of the upper and lower surfaces of the slot and each stiffening bridge, - the casing comprises a first orifice and a second orifice passing through the casing between an outer surface of the casing and the outer surface of the tube formed by the slot, and in that the first and second orifices are respectively in fluidic relation with the increasing and decreasing evolving sections, allowing a movement of the cooling fluid along the single heat exchange chamber of the water guide, the first and second orifices being intended to be connected to conduits of a cooling system, - the water guide is made at least partially of plastic material.

[0008] The invention also relates to a motor vehicle comprising an arrangement having at least one of the aforementioned characteristics. According to the invention, the motor vehicle comprises all or part of the aforementioned features of the arrangement and a cooling system, according to which the cooling system comprises a first pipe connected to the first orifice of the crankcase and a second pipe connected to the second orifice of the crankcase.

[0009] Other details, features and advantages will become clearer upon reading the detailed description given below, by way of example and not limitation, in relation to the various embodiments illustrated in the following figures: - Fig. 1 is a first illustration of an embodiment of a housing for an arrangement according to the invention; - [Fig.2] is a cross-sectional view of the housing of [Fig.1]; - [Fig.3] is an illustration of a first embodiment of a water guide of an arrangement according to the invention; - [Fig.4] illustrates the arrangement of the water guide of [Fig.3] and a first path of a cooling fluid circulating in the crankcase according to the first embodiment of the invention; - [Fig.5] is an illustration of a second embodiment of a water guide of an arrangement according to the invention; - [Fig.6] illustrates the arrangement of the water guide of [Fig.5] and a second path of a cooling fluid circulating in the crankcase according to the second embodiment of the invention.

[0010] According to one embodiment of the invention, the arrangement 10 of a stator housing for a rotating electrical machine in a motor vehicle is described below. The motor vehicle may be an electric or hybrid vehicle, the powertrain of which is equipped with a housing and a water guide, which will be described below. Furthermore, the vehicle may be a passenger car, a commercial vehicle, or a public transport vehicle.

[0011] The motor vehicle is equipped with an electric motor, of the rotary electric machine type, comprising a stator and an arrangement 10 according to the invention, the arrangement 10 comprising a stator housing 1.

[0012] The stator housing 1 is an external structure of the electrical machine that protects the internal components of the electrical machine. In the embodiment presented later in this document, the housing 1 extends along a given axis X between a first plane PI and a second plane P2, the first plane PI and the second plane P2 being perpendicular to the given axis X.

[0013] Furthermore, as can be more specifically seen in [Fig. 1] and [Fig. 2], the housing 1 of an arrangement 10 according to the invention comprises: - a cylindrical bore 11 along the given axis X intended to house the stator, and - a slot 12 in the shape of a cylindrical tube extending along the given axis X, the cylindrical tube being hollowed out in the casing 1 between the first plane PI and a third plane P3 located between the first plane PI and the second plane P2.

[0014] In other words, the third plane P3 delimits a depth of the slit 12, a depth of the slit 12 is equal to a distance measured along the X axis between the plane PI and the plane P3.

[0015] The slot 12 comprises an outer surface 121 and an inner surface 122. The outer surface 121 is a first cylindrical surface with a given axis X which defines an outer boundary of the slot 12. The inner surface 121 is a second cylindrical surface with a given axis X which defines an inner boundary of the slot 12. The first and second cylindrical surfaces 121, 122 are concentric, the second surface 122 being located inside the first surface 121. The outer surface 121 and inner surface 122 correspond to walls of the housing which must be cooled by the circulation of a cooling fluid in the slot 12 in order to maintain the temperature of the stator in a temperature range acceptable for its operation. Furthermore, slot 12 includes an open end 123 located in plane PI, the open end 123 allowing the insertion of a water guide into slot 12. After the water guide is inserted into slot 12, the open end 123 is intended to be sealed by a cover screwed onto the housing at plane PI. Slot 12 also includes a closed end 124 located in plane P3, the closed end sealing slot 12 at plane P3.

[0016] The arrangement 10 also includes a water guide 2. In the remainder of this document, the term "water guide" is used to designate a component capable of channeling or guiding a flow of a cooling fluid. A water guide comprises walls directing the cooling fluid near or in contact with areas to be cooled. The cooling fluid may be, for example, water or glycol water. Other cooling fluids may be used.

[0017] A water guide 2 of an arrangement 10 according to the invention is disposed in the slot 12 such that a first end ring extends in the first plane PI and a second end ring extends in the third plane P3. The water guide 2 of an arrangement 10 according to a first embodiment of the invention of [Fig.3] further comprises a helical wall 24 connecting said first and second rings 21, 22 to each other. The water guide 2 of an arrangement 10 according to a second embodiment of the invention of [Fig.5] further comprises at least one connecting wall 23 of said first and second rings 21, 22 between them. In other words, the water guide 2 extends over the entire depth of the slot 12. In addition, the water guide 2 is of the cage type which includes the first and second rings 21, 22 which according to the arrangement 10 extend radially between the outer surface 121 and inner surface 122 of the cylindrical tube formed by the slot 12. At least one connecting wall 23 extends radially between the outer surfaces 121 and inner surfaces 122 of the cylindrical tube formed by the slot 12 to define a path of a cooling fluid circulating in the water guide 2 between the first plane PI and the third plane P3 and in contact with the outer surfaces 121 and inner surfaces 122 of the cylindrical tube formed by the slot 12.

[0018] The manufacturing process by molding the housing 1 imposes an inclination between the inner 121 and outer 122 surfaces of the slot 12, such that the water guide 2 is substantially frustoconical.

[0019] Thus, according to the first embodiment illustrated in [1[Fig.3]], the helical wall 24 of the water guide 2 has a height that varies substantially according to the frustoconical profile of the slot 12, such that the height of the helical wall 24 near the plane PI is greater than the height of the wall near the plane P3.

[0020] Thus, according to the second embodiment illustrated in [Fig. 5], each connecting wall 23 of the water guide 2 is straight in shape and its height varies substantially according to the frustoconical profile of the slot 12, such that the height of the wall 23 near plane PI is greater than the height of the wall near plane P3. An outer surface and an inner surface of the water guide 2 are distinguished such that the outer surface is in contact with the outer surface 121 of the cylindrical tube formed by the slot 12 and the inner surface is in contact with the inner surface 122 of the cylindrical tube formed by the slot 12 with a support sufficiently strong to prevent the passage of the cooling fluid at the point of contact between each of the connecting walls 23 or the helical wall 24 of the water guide and the outer surface 121 and inner surface 122.

[0021] The water guide 2 according to the invention is at least partially made of a plastic material, in particular according to a molding process.

[0022] The first and second embodiments of the water guide 2 taken in isolation are respectively illustrated by [Fig.3] and [Fig.5].

[0023] In the first embodiment shown in [Fig. 3], a cooling fluid path defined by the helical wall 24 of the water guide 2 is in the form of a spiral 243 winding around the given axis X and extending between the first plane PI and the third plane P3. A diagram of a spiral cooling fluid circulation is shown in [Fig. 4]. Such a cooling fluid path is obtained by means of a helical wall 24 about the given axis X which extends between the outer surface 121 and inner surface 122 of the cylindrical tube formed by the slot 12.

[0024] According to the first embodiment, the arrangement of the stator housing including the water guide 2 allows the creation of a single heat exchange chamber 242 having several revolutions around the cylinder bore 11 of given axis X, the single chamber extending putting into fluidic communication the first and a second orifice 13, 14 connected to a cooling system, in particular on air, in order to allow the heat to be taken from the housing 1 in order to cool it. Given the design of the helical wall 24, which has a height greater than its width, the water guide 2 includes stiffening brackets 25 connecting the turns to each other with the first and second end rings 21, 22. Each bracket 25 runs parallel to the given axis X. Each bracket 25 is shorter than the height of the helical wall such that the fluid Cooling is likely to circulate between the bridge and at least one of the outer surfaces 121 and inner surfaces 122 of the cylindrical tube formed by the slot 12. The bridges 25 can be made of a material with increased rigidity compared to that of the helical wall 24. The bridges 25 can be made by overmolding the helical wall 24 and the first and second end rings 21, 22. The stiffening bridges 25 can be between 3 and 12 in number, preferably 8 in number. The bridges 25 are uniformly distributed around the given axis X, preferably spaced from each other by the same angle, in particular by an angle of 45° according to the preferred method illustrated in [Fig.3]. According to the first embodiment, the spiral circulation of the cooling fluid in the crankcase 1 tends to uniformize the temperature of the crankcase 1 around the given axis X.

[0025] In the second embodiment represented by [Fig. 5] and [Fig. 6], a cooling fluid path defined by at least one connecting wall 23 of the water guide 2 is in the form of a coil 233 making back-and-forth movements parallel to the given axis X between the first plane PI and the third plane P3. A diagram of a cooling fluid circulation in the form of a coil is shown in [Fig. 6]. Such a cooling fluid path is obtained by means of at least one connecting wall 23 oriented along the given axis X and extending between the outer surface 121 and inner surface 122 of the cylindrical tube formed by the slot 12. The water guide 2 can comprise between 4 and 16 connecting walls 23, preferably 12 connecting walls distributed around the cylinder forming the end walls 21 and 22, in a uniform angular manner, as shown in [Fig. 5].Each connecting wall 23 includes an opening located approximately at one of its ends. Taking into account the change in height of the connecting wall 23 between planes PI and P3, the opening can be substantially cylindrical near plane PI and substantially rectangular near plane P3 where the connecting wall 23 is of lesser height than the height of the connecting wall near plane PL. The flow of the cooling fluid takes place along a succession of heat exchange chambers 232, the communication from one chamber to an adjacent chamber taking place through an opening 231.

[0026] According to the second embodiment, the cooling fluid circulates from one chamber to another in an alternation between planes PI and P3, which tends to uniformize the temperature of the casing 1 along the given axis X. The circulation of the coolant within the crankcase 1 is made possible by the connection of ports 13, 14 to a vehicle cooling system which allows the coolant to enter the water guide 2 and then exit of the water guide 2. Advantageously, the first port 13 and the second port 14 are intended to be connected to conduits of a cooling system. In one embodiment, the motor vehicle further comprises a cooling system, the cooling system comprising a first conduit connected to the first port 13 for the inlet of a cooling fluid into the arrangement 10 and a second conduit connected to the second port 14 for the outlet of the cooling fluid from the arrangement 10.

[0027] Finally, thanks to the arrangement according to the invention, the water guide makes it possible to improve the heat transfer of an area of ​​the casing which is in contact with the stator, and of an area of ​​the casing which is in contact with the external environment, in particular the air via the external surface 15, which thus tends to optimize the cooling of the stator.

Claims

Demands

1. An arrangement (10) comprising a housing (1) for a stator of a rotating electrical machine, the housing (1) extending along a given axis (X) between a first plane (P1) and a second plane (P2), the first plane (P1) and the second plane (P2) being perpendicular to the given axis (X), the housing (1) comprising: - a cylindrical bore (11) along the given axis (X) for containing the stator, and - a slot (12) substantially in the form of a cylindrical tube extending along the given axis (X), the cylindrical tube being cut into the housing (1) between the first plane (P1) and a third plane (P3) situated between the first plane (P1) and the second plane (P2), the third plane (P3) being perpendicular to the given axis (X), the arrangement (10) being characterized in that it further comprises a water guide (2) inserted in the slot (12) so as to extend between the first plane (PI) and the third plane (P3), and in that the water guide (2) comprises - a first ring (21),in particular an end ring connected to a second ring (22), in particular a ring of opposite end, by at least one connecting wall (23) or by a helical wall (24), the first and second end rings being coaxial to the given axis (X), - each ring and / or each connecting wall and / or the helical wall extends between the outer (121) and inner (122) surfaces of the cylindrical tube formed by the slot (12) to define a path of a cooling fluid circulating in the slot (12) between the first plane (PI) and the third plane (P3) and in contact with the outer (121) and inner (122) surfaces of the cylindrical tube.

2. An arrangement (10) according to any one of the preceding claims, characterized in that a path of a cooling fluid defined by the water guide (2): - in the form of a coil making back-and-forth movements between the connecting walls (23) parallel to the given axis (X) between the first plane (PI) and the third plane (P3), or - in the form of a spiral winding around the given axis (X) along the turns of the helical wall (24) and extending between the first plane (PI) and the third plane (P3).

3. Arrangement (10) according to the preceding claim, characterized in that it comprises several connecting walls (23) distributed angularly equidistant around the given axis (X).

4. Arrangement (10) according to at least one of the preceding claims, characterized in that at least one connecting wall (23) is substantially straight and parallel to the given axis (X).

5. Arrangement (10) according to the preceding claim, characterized in that the connecting walls (23) in pairs delimit in combination with the outer (121) and inner (122) surfaces of the slot (12), a heat exchange chamber (232) and in that each connecting wall (23) includes at least one through opening (231) for the circulation of the cooling fluid through the connecting wall (23) for circulation of the cooling fluid towards the heat exchange chamber (232) which is directly adjacent to it.

6. Arrangement (10) according to the preceding claim, characterized in that the openings (231) of successive connecting walls are alternately arranged at either end of the water guide (2), and in that the housing (1) comprises a first orifice (13) and a second orifice (14) passing through the housing between an outer surface (15) of the housing and the outer surface (121) of the tube formed by the slot (12), the first and second orifices being respectively in fluidic relationship with two adjacent heat exchange chambers (232), the heat exchange chambers (232) and the openings (231) allowing a serpentine flow of the cooling fluid, the first and second orifices (13; 14) being intended to be connected to conduits of a cooling system.

7. Arrangement (10) according to claim 1 or 2, characterized in that the helical wall (24) defines a single spiral-shaped heat exchange chamber (242) comprising several turns (241), in particular between 2 and 5 turns, the chamber having a cross-section that varies between one of the end rings (21, 22) and the turn (241) directly adjacent to it, in particular having a cross-section that varies increasing in size near one of the end rings of the water guide, and in particular of decreasing evolving cross-section near the other end, according to the direction of flow of the cooling fluid.

8. Arrangement (10) according to the preceding claim, characterized in that the turns (241) of the helical wall (24) are connected to each other by stiffening bridges (25) parallel to the given axis (X), each stiffening bridge extending over at least a part of the height of the helical wall such that the cooling fluid is able to circulate between at least one of the upper and lower surfaces (121, 122) of the slot (12) and each stiffening bridge (25).

9. Arrangement (10) according to claim 7 or 8, characterized in that the housing (1) comprises a first orifice (13) and a second orifice (14) passing through the housing between an outer surface (15) of the housing and the outer surface (121) of the tube formed by the slot (12), and in that the first and second orifices (13, 14) are respectively in fluidic relationship with the increasing and decreasing evolving sections, allowing a movement of the cooling fluid along the single heat exchange chamber (242) of the water guide (2), the first and second orifices (13; 14) being intended to be connected to conduits of a cooling system.

10. Arrangement (10) according to at least one of the preceding claims, characterized in that the water guide (2) is made at least partially of plastic material.

11. Motor vehicle comprising an arrangement (10) according to any one of the preceding claims.

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