Arrangement comprising a casing of a stator of a rotary electric machine and a water guide

Abstract

The invention relates to an arrangement (10) comprising a casing (1) extending along a given axis (X), the casing (1) comprising: - a cylindrical bore (11) along the given axis (X) intended to contain the stator, and - a slot (12) in the form of a cylindrical tube extending along the given axis (X), the arrangement (10) further comprising a water guide (2) inserted into the slot (12) and comprising: - a first wall (21) covering an outer surface (121) of the cylindrical tube, and - a second wall (22) extending between the first wall (21) and an inner surface of the cylindrical tube, the second wall (22) being perpendicular to the first wall (21) and collaborating with the inner surface (122) of the cylindrical tube to define a path of a cooling fluid circulating in the water guide (2).

Description

[0001] DESCRIPTION

[0002] TITLE: Arrangement comprising a housing for a stator of a rotating electrical machine and a water guide.

[0003] 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.

[0004] A stator is a component of an electrical machine made up of welded or glued metal sheets and copper wires that allow the passage of a high-voltage, high-current electric current through the metal sheets. However, this 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.

[0005] Cooling solutions exist. For example, for crankcases made using low-pressure die-cast (LPDC) casting, one solution is to incorporate a specially shaped cavity within the crankcase to allow the circulation of a cooling fluid. For crankcases made using high-pressure die-cast (HPDC) casting, such a cavity can be created between two crankcases. Another option is to create a cavity with an open core within an HPDC-cast crankcase, where the specific shape of the water circulation cavity is ensured by an added water guide.

[0006] However, existing cooling solutions have drawbacks. In particular, they do not optimize stator cooling. The aim 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 provides a simple and reliable arrangement that improves the efficiency of stator cooling.

[0007] To this end, the invention relates to an arrangement comprising 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.

[0008] In addition, the crankcase includes:

[0009] - a cylindrical bore along the given axis intended to house the stator, and

[0010] - a slot in the form 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 arrangement further comprising a water guide inserted into the slot of the stator casing so as to extend between the first and third planes.

[0011] The water guide also includes:

[0012] - a first wall covering an outer surface of the cylindrical tube formed by the slot, in particular with complete coverage of the outer surface, and

[0013] - at least one second wall extending between the first wall and an inner surface of the cylindrical tube formed by the slot, this second wall being substantially perpendicular to the first wall, and this second wall interacting with the inner surface of the cylindrical tube formed by the slot to define a path for a cooling fluid circulating in the water guide between the first and third planes and in contact with the inner surface of the cylindrical tube formed by the slot. In one embodiment, the water guide is made of a thermally insulating material such that the first wall of the water guide is a thermal insulation screen intended to at least reduce the heat exchange between the cooling fluid and the outer surface of the cylindrical tube formed by the slot.

[0014] In one embodiment, the water guide is made at least partially of plastic material.

[0015] In one embodiment, a path of a cooling fluid defined by at least a second wall of the water guide is

[0016] - in the form of a serpentine line moving back and forth parallel to the given axis between the foreground and background, or

[0017] - in the form of a spiral winding around the given axis and extending between the foreground and background.

[0018] In one embodiment, the housing includes 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 wall of the water guide including a third orifice disposed opposite the first orifice of the housing and a fourth orifice disposed opposite the second orifice of the housing, the first orifice, the second orifice, the third orifice and the fourth orifice together allowing a movement of the cooling fluid along at least one second wall of the water guide.

[0019] In one embodiment, the first orifice and the second orifice are intended to be connected to ducts of a cooling system.

[0020] The invention further relates to a motor vehicle comprising an arrangement according to the invention. The invention also relates to a motor vehicle comprising an arrangement according to the invention and a cooling system, the cooling system comprising a first pipe connected to the first orifice of the crankcase and a second pipe connected to the second orifice of the crankcase.

[0021] Further details, features and advantages will become clearer upon reading the detailed description given below, which is indicative and not exhaustive, in relation to the various implementation examples illustrated in the following figures:

[0022] Figure 1 is a first illustration of an embodiment of a housing for an arrangement according to the invention.

[0023] Figure 2 is a second illustration of an embodiment of a housing for an arrangement according to the invention.

[0024] Figure 3 is a first illustration of a first embodiment of a water guide of an arrangement according to the invention.

[0025] Figure 4 illustrates a first path of a cooling fluid circulating in a water guide according to the first embodiment of the invention.

[0026] Figure 5 is a second illustration of the first embodiment of a water guide of an arrangement according to the invention.

[0027] Figure 6 is a first illustration of a second embodiment of a water guide of an arrangement according to the invention.

[0028] Figure 7 illustrates a second path of a cooling fluid circulating in a water guide according to the second embodiment of the invention.

[0029] Figure 8 is a second illustration of the second embodiment of a water guide of an arrangement according to the invention.

[0030] An embodiment of a motor vehicle 100 is described below with reference to Figure 1. The motor vehicle 100 can be an electric or hybrid vehicle. Furthermore, the vehicle 100 can be a passenger car, a commercial vehicle, or a public transport vehicle.

[0031] The motor vehicle 100 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.

[0032] 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 P1 and a second plane P2, the first plane P1 and the second plane P2 being perpendicular to the given axis X.

[0033] Furthermore, as can be more specifically seen in Figures 1 and 2, the housing 1 of an arrangement 10 according to the invention comprises

[0034] - a cylindrical bore 1 along the given axis X intended to contain the stator, and

[0035] - 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 P1 and a third plane P3 located between the first plane P1 and the second plane P2.

[0036] 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 P1 and the plane P3.

[0037] 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.

[0038] The outer surface 121 corresponds to a wall of the housing that is not in direct contact with the stator. Therefore, it is not necessary to cool the outer surface 121 of the slot 12. However, the inner surface 121 corresponds to a wall of the housing that is in direct contact with the stator. It is therefore essential that the inner surface 121 of the slot 12 be cooled to maintain the stator temperature within an acceptable range.

[0039] In addition, the slot 12 includes an open end 123 disposed in the plane P1, the open end 123 allowing a water guide to be inserted into the slot 12. After insertion of a water guide into the slot 12, the open end 123 is intended to be sealed by a cover screwed onto the housing at the level of the plane P1.

[0040] The slot 12 further includes a closed end 124 disposed in the plane P3, the closed end providing a seal of the slot 12 at the level of the plane P3.

[0041] Arrangement 10 also includes a water guide 2. In the remainder of this document, the term "water guide" refers to a component designed to channel or guide the flow of a cooling fluid. A water guide comprises walls that direct the cooling fluid near or into contact with areas to be cooled. The cooling fluid may be, for example, water or glycol water. Other cooling fluids may also be used.

[0042] A water guide 2 of an arrangement 10 according to the invention is disposed in the slot 12 so as to extend between the first plane P1 and the third plane P3. In other words, the water guide extends over the entire depth of the slot 12.

[0043] In addition, Water Guide 2 includes:

[0044] - a first wall 21 covering an external surface 121 of the cylindrical tube formed by the slot 12, in particular with complete coverage of the external surface, and

[0045] - at least one second wall 22 extending between the first wall 21 and an internal surface 122 of the cylindrical tube formed by the slot 12, the at least one second wall 22 being substantially perpendicular to the first wall 21.

[0046] At least one second wall 22 collaborates with the inner surface 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 P1 and the third plane P3 and in contact with the inner surface 122 of the cylindrical tube formed by the slot 12.

[0047] Thus, in order to cover the outer surface 121 of the cylindrical tube formed by the slot 12, the first wall 21 of the water guide 2 is cylindrical in shape,

[0048] - the outer diameter 211 of the first wall 21 being substantially equal to the diameter 1211 of the outer surface 121 of the cylindrical tube formed by the slot 12, and

[0049] - the inner diameter 212 of the first wall 21 being strictly greater than the diameter 1221 of the inner surface 122 of the cylindrical tube formed by the slot 12.

[0050] An outer surface 213 of the first wall 21 and an inner surface 214 of the first wall 21 are distinguished. The outer surface 213 of the first wall 21 is in contact with the outer surface 121 of the cylindrical tube formed by the slot 12. Furthermore, there is a gap 223 separating the inner surface 214 of the first wall 21 and the inner surface 122 of the cylindrical tube formed by the slot 12. The gap 223 is traversed by at least one second wall 22 of the water guide 2. This at least one second wall 22 extends between the first surface 21 of the water guide and the inner surface 122 of the cylindrical tube formed by the slot 12. Advantageously, this at least one second wall 22 bears against the inner surface 122, the bearing being strong enough to prevent the passage of the cooling fluid at the point of contact between the second wall 22 and the inner surface 122.

[0051] The water guide 2 according to the invention can be at least partially made of a thermally insulating material, in particular the first wall 21 of the water guide 2 is made of a thermally insulating material, such that the first wall 21 of the water guide 2 is a thermal insulation screen intended to at least reduce the heat exchange between the cooling fluid and the outer surface 121 of the cylindrical tube formed by the slot 12.

[0052] In other words, the first wall 21 of the guide 2 prevents heat transfer between a cooling fluid circulating in the water guide 2 and the outer surface 121 of the cylindrical tube formed by the slot 12. In one embodiment, the water guide 2 is made of plastic material, such as for example butylene terephthalate, or of synthetic polymer, such as polyamide also known as nylon, of type PA6 or PA66 or equivalent.

[0053] A first embodiment 23 and a second embodiment 24 of a water guide 2 according to the invention are respectively illustrated by figures 3 and 6.

[0054] In the first embodiment 23 shown in Figures 3 to 5, a path of a cooling fluid defined by at least one second wall 22 of the water guide 2 is in the form of a spiral 222 winding around the given axis X and extending between the first plane P1 and the third plane P3. A diagram of a spiral cooling fluid circulation is shown in Figure 4. Such a path of the cooling fluid is obtained by means of a wall 22 extending between the inner surface 214 of the first wall and the first wall 21 and the inner surface 122 of the cylindrical tube formed by the slot 12, the wall 22 having a spiral shape with a given axis X.

[0055] In the second embodiment 24 shown in Figures 6 to 8, a cooling fluid path defined by at least one second wall 22 of the water guide 2 is in the form of a coil 221 making back-and-forth movements parallel to the given axis X between the first plane P1 and the third plane P3. A diagram of a cooling fluid circulation in the form of a coil is shown in Figure 7. Such a cooling fluid path is obtained by means of a plurality of walls 22 oriented along the given axis X and extending between the inner surface 214 of the first wall 21 and the inner surface 122 of the cylindrical tube formed by the slot 12.

[0056] In the second embodiment of the water guide 2, three types 224, 225, 226 of walls 22 are distinguished:

[0057] - walls 22 of a first type 224 are pierced at one end of wall 22 located near plane P1,

[0058] - walls 22 of a second type 225 are pierced at one end of wall 22 located near plane P3, and

[0059] - a wall 22 of a third type 226 is not pierced.

[0060] The walls 22 of the first and second type 224, 225 are arranged alternately, so as to implement a cooling fluid path in the shape of a serpentine 221. The wall 22 of the third type 226 is arranged so as to separate a fluid inlet zone into the water guide 2 and a fluid outlet zone out of the water guide 2.

[0061] As illustrated by Figure 5, the housing 1 includes 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 the first wall 21 of the water guide includes a third orifice 215 disposed opposite the first orifice 13 of the housing 1 and a fourth orifice 216 disposed opposite the second orifice 14, and the first orifice, the second orifice, the third orifice and the fourth orifice together permit a movement of the cooling fluid along at least a second wall 22 of the water guide 2.

[0062] Ports 13, 14, 215, 216 thus allow a cooling fluid to enter the water guide 2 and then exit from the water guide 2.

[0063] Advantageously, the first orifice 13 and the second orifice 14 are intended to be connected to ducts of a cooling system.

[0064] In one embodiment, the motor vehicle 100 further includes a cooling system, the cooling system comprising a first pipe connected to the first port 13 for the entry of a cooling fluid into the arrangement 10 and a second pipe connected to the second port 14 for the exit of the cooling fluid out of the arrangement 10.

[0065] Finally, thanks to the thermally insulating surface of the water guide, the arrangement according to the invention reduces or even eliminates heat exchange between the cooling fluid and the external part of the housing that does not need to be cooled. Thus, the arrangement according to the invention allows heat transfer to be channeled towards an area of ​​the housing that is in contact with the stator, thereby optimizing stator cooling.

Claims

DEMANDS 1. 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 (1 1 ) along the given axis (X) intended to contain the stator, and - a slot (12) 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 arrangement (10) being characterized in that it further comprises a water guide (2) inserted into the slot (12) of the stator housing (1) so as to extend between the first plane (P1) and the third plane (P3), and in that the water guide (2) comprises: - a first wall (21) covering an outer surface (121) of the cylindrical tube formed by the slot (12), in particular with complete coverage of the outer surface, and - at least one second wall (22) extending between the first wall (21) and an inner surface (122) of the cylindrical tube formed by the slot (12), the at least one second wall (22) being substantially perpendicular to the first wall (21), and the at least one second wall (22) collaborating with the inner surface (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 (P1) and the third plane (P3) and in contact with the inner surface (122) of the cylindrical tube formed by the slot (12).

2. Arrangement (10) according to the preceding claim, characterized in that the water guide (2) is made of a thermally insulating material such that the first wall (21) of the water guide (2) is a thermal insulation screen intended to at least reduce the heat exchange between the cooling fluid and the outer surface (121) of the cylindrical tube formed by the slot (12).

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

4. An arrangement (10) according to any one of the preceding claims, characterized in that a path of a cooling fluid defined by at least a second wall (22) of the water guide (2) is - in the form of a serpentine (221) making back-and-forth movements parallel to the given axis (X) between the first plane (P1) and the third plane (P3), or - in the form of a spiral (222) winding around the given axis (X) and extending between the first plane (P1) and the third plane (P3).

5. An arrangement (10) according to any one of the preceding claims, 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), in that the first wall (21) of the water guide comprises a third orifice (215) disposed opposite the first orifice (13) of the housing (1) and a fourth orifice (216) disposed opposite the second orifice (14) of the housing (1), and in that the first, second, third, and fourth orifices together allow fluid movement cooling along at least a second wall (22) of the water guide (2).

6. Arrangement (10) according to the preceding claim, characterized in that the first orifice (13) and the second orifice (14) are intended to be connected to conduits of a cooling system.

7. Motor vehicle (100) comprising an arrangement (10) according to any one of the preceding claims.

8. Motor vehicle comprising an arrangement (10) according to claim 6 and a cooling system, characterized in that the cooling system comprises a first pipe connected to the first orifice (13) of the casing (1) and a second pipe connected to the second orifice (14) of the casing (1).

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