Non-drive end casing element of an electric machine housing for an electric drive assembly of a vehicle

Abstract

The invention relates to a non-drive end casing element (6) for an electric transmission assembly (1) of a vehicle, the non-drive end casing element (6) being configured to be associated with an electric machine (2) and comprising: - a bell which comprises a rear wall and an outer skirt intended to house one end of the electric machine (2) and which comprises a flange equipped with a first seal; - the rear wall of the bell comprising an opening intended to be crossed by the rotor shaft (9) and which opens into a cavity intended to receive an angular position sensor, said cavity being arranged on a second side of the non-drive end casing element (6), opposite the first side, and being constituted by a cavity edge equipped with a second seal;- the rear wall of the bell further comprises a hole intended to be crossed by an electrical connection assembly (18) for connecting the electric machine (2) to a control module of the electric machine (4); the non-drive end casing element (6) comprises a projecting rim which surrounds the hole, the projecting rim being equipped with a third seal. Figure for summary: 1;

Description

Title of the invention: Non-drive end casing element of an electric machine housing for an electric drive assembly of a vehicle Technical field

[0001] The invention relates to the field of electric or hybrid vehicles.

[0002] More particularly, the invention relates to a non-drive end housing member of an electric machine housing for an electric drive assembly of a vehicle, an electric drive assembly comprising the non-drive end housing member and a vehicle comprising the electric drive assembly.

[0003] Technological context

[0004] The electric drive assembly generally includes an electric rotating machine, a gearbox assembly, a control module of the electric machine, an electrical connection assembly that connects the control module of the electric machine to the electric rotating machine and sensors, such as an angular position sensor that outputs the angular position of the rotor shaft. The electric drive assembly includes several sealing interfaces and more particularly: a sealing interface between the housing of the electric machine and a non-drive end casing element that closes one side of the housing of the electric machine, a sealing interface that seals the electrical connection assembly and a sealing interface that seals a cavity in which the angular position sensor is housed.

[0005] These sealing interfaces are produced using several subassemblies, which makes series assembly and robust sealing difficult to achieve.

[0006] Summary

[0007] One of the underlying concepts of the invention is therefore to provide an electric transmission assembly that is easier to assemble and offers more robust sealing interfaces.

[0008] To this end, according to a first aspect, the invention provides a non-drive end casing element for an electric transmission assembly of a vehicle, the non-drive end casing element being configured to be associated with an electric machine comprising a rotor which is non-rotatably connected to a rotor shaft, a stator and an electric machine housing in which the rotor and the stator are at least partially housed; the non-drive end casing element comprising: - a bell which projects from a first side of the non-drive end casing element and comprises a rear wall and an outer skirt which is intended to house one end of the electric machine and which comprises a flange equipped with a first seal which is intended to ensure sealing between the bell and the casing of the electric machine;

[0009] - the rear wall of the bell comprising an opening which is intended to be crossed by the rotor shaft and which opens into a cavity intended to receive an angular position sensor, said cavity being arranged on a second side of the non-driving end casing element, and being constituted by a cavity edge which projects axially, and is equipped with a second sealing gasket intended to ensure sealing between the cavity edge and a cavity cover; - the rear wall of the bell further comprises a hole intended to be crossed by an electrical connection assembly for connecting the electric machine to a control module of the electric machine; the non-drive end casing element comprises on the second side, a protruding rim which surrounds the hole, the protruding rim being equipped with a third seal intended to ensure sealing between the protruding rim and a housing of the control module of the electric machine.

[0010] Thus, this non-drive end casing member can tightly connect the electric machine housing, the electric machine control module and the cavity cover and provides the sealing interfaces for the aforementioned members. This enables the sealing interfaces to be grouped on the same member, reduces the mechanical stress in the assembly and simplifies the assembly of the entire electric transmission.

[0011] According to the embodiments, such a non-drive end casing element may have one or more of the following characteristics.

[0012] According to one embodiment, said cavity is arranged on a second side of the non-drive end casing element, opposite the first side.

[0013] According to one embodiment, at least one of the first, second and third seals is a cured-in-place seal. Advantageously, all of the first, second and third seals are cured-in-place seals.

[0014] This further simplifies manufacturing by avoiding the need to handle prefabricated joints which tend to lead to failures in an automated process.

[0015] According to one embodiment, the rear wall of the bell comprises an annular skirt which is arranged around the opening, and which constitutes a bearing housing intended to house a bearing arranged to guide the rotor shaft in rotation.

[0016] According to one embodiment, the cavity edge comprises a window which passes through said cavity edge and opens into the cavity, the window being designed to receive a connector intended to be connected to the angular position sensor and the control module of the electric machine.

[0017] According to one embodiment, the rear wall of the bell comprises a hole for positioning a sensor, such as a temperature sensor.

[0018] According to one embodiment, the flange comprises several openings allowing the outer skirt to be fixed to the housing of the electric machine.

[0019] According to one embodiment, the edge of 1 cavity includes a plurality of openings allowing the cavity cover to be attached to the non-drive end housing member to close the cavity.

[0020] According to one embodiment, the non-drive end casing element is manufactured in a single piece, advantageously molded from a metallic or alloy material.

[0021] According to one embodiment, the non-drive end housing element comprises a plurality of openings arranged on the second side, and allowing the housing of the control module of the electric machine to be fixed to the non-drive end housing element.

[0022] According to one embodiment, the invention also provides an electric drive assembly comprising the aforementioned housing element, an angular position sensor housed in the cavity, a cavity cover attached to the edge of the recess and an electric machine comprising a rotor non-rotatably connected to a rotor shaft, a stator and an electric machine housing in which the rotor and the stator are at least partially housed, one end of the electric machine being housed in the bell, the electric machine housing being attached to the flange of the bell and the rotor shaft passing through the opening.

[0023] According to one embodiment, the electric drive assembly further comprises an electric machine control module attached to the non-drive end housing member and an electrical connection assembly that passes through the hole and is connected to an interconnector of the electric machine and to electrical connectors of the electric machine control module; the electric machine control module comprising a housing, the housing comprising a protruding portion that is positioned opposite the protruding rim and that is pressed against the third seal, the protruding portion comprising a hole allowing passage of a tool to secure the electrical connection assembly to the electrical connectors of the electric machine control module, a fourth seal being disposed around the hole of the protruding portion and providing a seal between a second cover and the protruding portion.

[0024] According to one embodiment, the electric machine control module is attached to the non-drive end housing member on the non-drive side.

[0025] According to one embodiment, the control module of the electric machine comprises an inverter configured to convert direct current into alternating current for powering the electric machine.

[0026] According to one embodiment, the invention also provides a motor vehicle comprising the aforementioned electric drive assembly. Brief description of the figures

[0027] The invention will be better understood and other objects, details, characteristics and advantages will appear more clearly in the following description of several embodiments of the invention, which are given only by way of illustration and in a non-limiting manner, with reference to the accompanying drawings.

[0028] [Fig.l] is a schematic view of an electric drive assembly.

[0029] [Fig.2] is a perspective view of the non-drive end casing member, showing the side intended to face the electric machine.

[0030] [Fig. 3] is a perspective view of the non-drive end housing member, showing the side intended to face the electric machine control module.

[0031] [Fig.4] is a detailed perspective view of the non-drive end casing member and the protruding portion of the electric machine control module.

[0032] [Fig.5] is a sectional view showing the electrical connection assembly and the protruding portion of the control module of the electric machine. Description of the embodiments

[0033] In the description and the claims, the terms "external" and "internal" as well as the orientations "axial" and "radial" will be used to designate, according to the definitions given in the description, elements of the electric drive assembly. By convention, the X axis of rotation of the rotor of the rotating electrical machine defines the "axial" orientation. The "radial" orientation is directed orthogonally to the X axis and, from the inside to the outside away from said X axis.

[0034] The electric drive assembly 1 is designed to equip a vehicle with a hybrid or electric motor.

[0035] As shown in [Fig.l], the electric drive assembly 1 comprises an electric machine 2, a gearbox assembly 3 and an electric machine control module 4. The electric drive assembly 1 also comprises an electric machine housing 5 in which the electric machine 2 is arranged and which has, for example, the general shape of a cylinder of revolution. The electric machine housing 5 is closed on one side, i.e. the driving end, by the gearbox assembly cover 3 and, on the other side, i.e. the non-driving end, by a non-driving end casing element 6.

[0036] The electrical machine 2 is for example a permanent magnet synchronous electrical machine or an alternating current asynchronous electrical machine. The electrical machine 2 comprises a rotor 7 and a stator 8. In the illustrated embodiment, the stator 8 radially surrounds the rotor 7 and the electrical machine 2 is a radial flux rotating electrical machine. However, in embodiments not illustrated, the electrical machine 2 is an axial flux rotating electrical machine, which means that it has at least one stator axially opposed to at least one rotor, so that the space between the rotor and the stator, and therefore the direction of the magnetic flux between the two, is aligned parallel to the axis of rotation, rather than radially.

[0037] The stator 8 comprises an iron core which carries windings. The iron core is formed from a plurality of grooves inside which the windings are inserted. The iron core comprises, for example, several plates, such as electrical steel plates, which are superimposed and sealed together to form a laminate.

[0038] According to an embodiment in which the electrical machine 2 is a permanent magnet synchronous electrical machine, the rotor 7 comprises permanent magnets which create a magnetic field synchronized with the rotating magnetic field produced by the stator windings. According to another embodiment in which the electrical machine is an asynchronous alternating current electrical machine, the rotor 7, composed of a conductive material, induces currents due to the change in magnetic field, which in turn creates a secondary magnetic field which interacts with the stator field, thereby causing the rotor to move.

[0039] The rotor 7 is rotatably mounted on the housing of the electric machine 5 about the axis of rotation X. More particularly, the rotor 7 is non-rotatably connected to a rotor shaft 9 which is rotatably mounted along the axis X. In the embodiment illustrated in [Fig.l], the rotor shaft 9 is guided in rotation by means of a pair of bearings 10, 11 which are respectively housed in a bearing housing 16, illustrated in [Fig.2], arranged in the non-drive end housing element 6 and in a bearing housing 17 arranged in the cover of the gearbox assembly 3.

[0040] The rotor shaft 9 passes through at least one hole 12 located in the cover of the gearbox 3 to be coupled to an input shaft, not shown, of the gearbox 3. The input shaft is for example arranged coaxially with the rotor shaft 9 and therefore receives the torque from the electric machine 2. It should be understood that the rotor shaft 9 and the input shaft of the gear may be two different shafts rotatably connected by a connecting element (for example, connected by splines) or may be the same shaft.

[0041] In the illustrated embodiment, the electric drive assembly 1 is intended to be arranged longitudinally between two wheels. In other words, the axle rotation X of the electric machine 2 is parallel to the axes of the wheels. In addition, the gearbox 3 also comprises a differential, not shown, which is coupled to the input shaft of the gearbox via gear sets. The differential allows the wheels to rotate at different speeds and to distribute the torque and load between the wheel axles. In the illustrated model, one of the wheel axles 15 passes through the holes 13, 14 arranged in the housing of the electric machine 5 and in the non-drive end casing element 6.

[0042] The electrical drive assembly 1 comprises an electrical connection assembly 18 which is configured to electrically connect the control module of the electrical machine 4 to the stator 8 of the electrical machine 2, and more precisely to an interconnector of the stator 8. Such an interconnector, not illustrated, is configured to connect the windings of the stator 8 to the electrical connection assembly 18. The electrical connection assembly 18 passes through a hole 19, described below in relation to FIGS. 2 and 3, provided in the non-drive end casing element 6.

[0043] As shown in [Fig.l], the electrical connection assembly 18 comprises several conductive bars (e.g., copper conductive bars). The number of conductive bars may be four, used for three current phases and the neutral, respectively.

[0044] With reference to Figures 2 and 3, the features of the non-drive end casing element 6 according to one embodiment will now be described. The non-drive end casing element 6 is advantageously manufactured in a single piece and is preferably molded from a metallic material or an alloy. [Fig. 2] shows the side of the non-drive end casing element 6 that faces the electric machine 2, while [Fig. 3] shows the side of the non-drive end casing element 6 that faces the control module of the electric machine 4.

[0045] As shown in [Fig. 2], the non-drive end casing element 6 comprises a bell 20 which projects towards the housing of the electric machine 5 and inside which is housed one end of the electric machine 2. The bell 20 has an outer skirt 21 and a rear wall 22. The bell 20 is fixed to the housing of the electric machine 5. For this purpose, the end of the outer skirt 21 comprises a flange 23 with a plurality of openings 24 distributed around the axis X, allowing the outer skirt 21 to be fixed to the housing of the electric machine 5 by means of fixing elements, such as screws. In addition, the flange 23 is equipped with a seal 25 intended to ensure sealing between the bell 20 and the housing of the electric machine 5.

[0046] According to a preferred embodiment, the seal 25 is a cure-in-place seal (CIPG). This seal 25 is obtained by applying the seal in liquid form, then curing it to create a strong and uniform compression seal. The seal 25 is for example made of a material selected from silicone and polyurethane. The curing process can be carried out by UV, by heat or by the reaction of a multi-component system. According to another embodiment, the seal 25 is prefabricated and subsequently installed in a corresponding groove provided in the flange 23.

[0047] The rear wall 22 of the bell 20 has an opening 26 through which the rotor shaft 9 of the electrical machine 2 can pass. Thus, as will be explained below, an angular position sensor configured to deliver a signal representative of the angular position of the rotor shaft 9 can be arranged on the other side of the non-drive end casing element 6.

[0048] The rear wall 22 of the bell 20 also comprises, around the opening 26, an annular skirt 27 which constitutes the housing of the bearing 16 intended to house one of the two bearings 10, 11 which guide the rotation of the shaft of the rotor 9.

[0049] The rear wall 22 of the bell 20 also comprises the hole 19 intended to be crossed by the electrical connection assembly 18 which electrically connects the control module of the electrical machine 4 and the stator 8 of the electrical machine 2, respectively arranged on either side of the non-drive end casing element 6.

[0050] In the illustrated embodiment, the rear wall 22 also comprises a hole 28 for positioning a temperature sensor configured to deliver a signal representative of the temperature of the rotor 7 and / or the stator 8.

[0051] In the illustrated version, the non-drive end casing element 6 also includes the hole 14 through which one of the wheel axles 15 passes.

[0052] As shown in [Fig. 3], the non-drive end housing element 6 comprises a cavity 29 into which the opening 26 for the rotor shaft 9 opens and which is defined by a cavity edge 30 which projects axially towards the control module of the electric machine 4. The cavity 29 serves as a housing for the angular position sensor. The cavity 29 is intended to be closed by a recess cover 31, illustrated in [Fig. 1]. For this purpose, the cavity 29 is flanked by a plurality of openings 32, such as threaded openings, arranged in the cavity edge 30, allowing the cavity cover 31 to be fixed to the non-drive end housing element 6 by means of fixing elements, such as screws.

[0053] The cavity edge 30 is equipped with a sealing gasket 33 intended to ensure sealing between said edge of the recess 30 and the cavity cover 31. The sealing gasket 33 is advantageously a CIPG (Cured-In-Place gasket) gasket, but it may also be a prefabricated gasket housed in a groove formed in the edge of the recess 30.

[0054] The non-drive end casing element 6 comprises a window 34 which is arranged in the edge of the recess 30 and passes through it so as to open into the cavity 29. The window 34 is designed to receive a connector 35, illustrated in [Fig.l]. The connector 35 is intended to be connected to the angular position sensor, on the one hand, and to the control module of the electric machine 4, on the other hand, and can thus transmit the signal representative of the angular position of the rotor shaft 9 from the angular position sensor to the control module of the electric machine 4. According to an advantageous embodiment, the temperature sensor arranged in the hole is also electrically connected to the connector 35.

[0055] According to one embodiment, the angular position sensor is a resolver. The resolver comprises a resolver rotor which is fixed to the end of the rotor shaft 9 projecting into the cavity 29 and a resolver stator which surrounds the resolver rotor. The resolver stator is electrically connected to the connector. According to another embodiment, the angular position sensor is an absolute encoder. The absolute encoder comprises, on the one hand, a circular disc fixed to the end of the rotor shaft 9 which projects into the cavity 29 and which has coded tracks representing the absolute angular information and, on the other hand, a read head or a sensor which is configured to detect the information coded on the disc as it rotates.

[0056] The non-drive end housing member 6 further comprises a plurality of openings 36, such as threaded openings, disposed on its side facing the electric machine control module and which allow the housing of the electric machine control module 4 to be secured to the non-drive end housing member 6 by means of fasteners, such as screws.

[0057] The control module of the electrical machine 4 is advantageously an inverter configured to convert direct current (DC) into alternating current (AC) to power the electrical machine 2. The inverter is also configured to control and regulate the output frequency and voltage.

[0058] The non-drive end casing element 6 comprises a projecting rim 37 which surrounds the hole 19 intended to be crossed by the electrical connection assembly 18. The projecting rim 37 projects axially towards the control module of the electric machine 4 and is intended to face a corresponding opening made in a housing of the control module of the electric machine 4. In addition, the projecting rim 37 is equipped with a seal 38 intended to ensure sealing between said projecting rim 37 and the housing of the control module of the electric machine 4. The seal 38 may be a CIPG (Cured-In-Place gasket) or a prefabricated seal.

[0059] As shown in Figures 4 and 5, the housing of the control module of the electric machine 4 comprises a projecting part 39 which is positioned opposite the projecting edge 37 and which is pressed against the seal 38. The projecting portion 39 comprises a hole 40 which allows the passage of a tool, such as a screwdriver, to fix the bars of the electrical connection assembly 18 to the electrical connectors of the control module of the electric machine 4. In addition, the projecting portion 39 also comprises a plurality of openings 42, such as threaded openings, allowing a second cover, not shown, to be fixed on the projecting portion 39. In addition, a seal 41 is disposed around the hole 40 and is intended to ensure sealing between the second cover and the projecting portion 39.

[0060] Although the invention has been described in relation to several embodiments, it is clear that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations, if these fall within the scope of the invention as claimed.

[0061] The use of the verbs "to have", "to understand" or "to include" and their conjugated forms does not exclude the presence of elements or steps other than those mentioned in a claim.

[0062] In the claims, any reference in parentheses should not be interpreted as a limitation of the claim.

Claims

Claims

1. A non-drive end housing element (6) for an electric transmission assembly (1) of a vehicle, the non-drive end housing element (6) being configured to be associated with an electric machine (2) comprising a rotor (7) which is non-rotatably connected to a rotor shaft (9), a stator (8) and an electric machine housing (5) in which the rotor (7) and the stator (8) are at least partially housed; the non-drive end casing element (6) comprises: - a bell (20) which projects from a first side of the non-drive end casing element (6) and which comprises a rear wall (22) and an outer skirt (21) intended to house one end of the electric machine (2) and which comprises a flange (23) equipped with a first seal (25) intended to ensure sealing between the bell (20) and the electric machine housing (5);- the rear wall (22) of the bell (20) comprising an opening (26) which is intended to be crossed by the rotor shaft (9) and which opens into a cavity (29) intended to receive an angular position sensor, said cavity (29) being arranged on a second side of the non-drive end casing element (6), and being constituted by a cavity edge (30) which projects axially and which is equipped with a second seal (33) intended to ensure sealing between the cavity edge (30) and a cavity cover (31); - the rear wall (22) of the bell (20) further comprises a hole (19) intended to be crossed by an electrical connection assembly (18) for connecting the electric machine (2) to a control module of the electric machine (4);the non-drive end casing element (6) comprises, on the second side, a projecting rim (37) which surrounds the hole (19), the projecting rim (37) being equipped with a third seal (38) intended to ensure sealing between the projecting rim (37) and a housing of the control module of the electric machine (4).;

2. The non-drive end housing member (6) of claim 1, wherein at least one of the first, second, and third seals (25, 33, 38) is a cured-in-place seal.

3. A non-drive end housing element (6) according to claim 1 or 2, wherein the rear wall (22) of the bell (20) comprises an annular skirt (27) which is arranged around the opening (26) and which constitutes a bearing housing (16) intended to house a bearing (10) arranged to guide the rotor shaft (9) in rotation.

4. A non-drive end casing element (6) according to any one of claims 1 to 3, wherein the cavity edge (30) comprises a window (34) which passes through said cavity edge (30) and opens into the cavity (29), the window (34) being adapted to receive a connector (35) intended to be connected to the angular position sensor and to the control module of the electric machine (4).

5. A non-drive end housing member (6) according to any one of claims 1 to 4, wherein the rear wall (22) of the bell (20) includes a hole (28) for positioning a sensor, such as a temperature sensor.

6. A non-drive end casing member (6) according to any one of claims 1 to 5, wherein the flange (23) has a plurality of openings for securing the outer skirt (21) to the housing of the electrical machine (5).

7. A non-drive end housing member (6) according to any one of claims 1 to 6, wherein the cavity edge (30) comprises a plurality of openings (32) allowing the cavity cover (31) to be secured to the non-drive end housing member (6) to close the cavity (29).

8. A non-drive end housing member (6) according to any one of claims 1 to 7, comprising a plurality of openings (36) arranged on the second side and for securing the housing of the control module of the electric machine (4) to the non-drive end housing member (6).

9. An electric drive assembly (1) comprising a non-drive end housing member (6) according to any one of claims 1 to 8, an angular position sensor housed in the cavity (29), a cavity cover (31) attached to the edge of the cavity and an electric machine (2) comprising a rotor (7) non-rotatably connected to a rotor shaft (9), a stator (8) and an electric machine housing (5) in which the rotor (7) and the stator (8) are at least partially housed, one end of the electric machine (2) being housed in the bell (20), the electric machine housing (5) being fixed to the flange (23) of the bell (20) and the rotor shaft (9) passing through the opening (26).

10. An electric drive assembly (1) according to claim 9, further comprising an electric machine control module (4) attached to the non-drive end housing member (6) and an electrical connection assembly (18) which passes through the hole (19) and is connected to an interconnector of the electric machine (2) and to electrical connectors of the electric machine control module (4);the control module of the electric machine (4) comprising a housing, the housing comprising a protruding portion (39) which is positioned opposite the protruding rim (37) and which is pressed against the third seal (38), the protruding portion (39) comprising a hole (40) allowing the passage of a tool in order to fix the electrical connection assembly (18) to the electrical connectors of the control module of the electric machine (4), a fourth seal (41) being arranged around the hole (40) of the protruding portion (39) and ensuring the seal between a second cover and the protruding portion (39).;

11. An electric drive assembly (1) according to claim 10, wherein the control module of the electric machine (4) comprises an inverter configured to convert direct current into alternating current for powering the electric machine (2).

12. Motor vehicle comprising an electric drive assembly (1) according to claims 9 to 11.

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