Propulsion module for vehicle

Abstract

To reduce occurrence of noise and vibration.SOLUTION: A propulsion module (1) for a vehicle includes a motor case (5) and a transmission case (6). The motor case (5) contacts with an end wall (37) of a first shell (18) of the transmission case (6) and includes a cylindrical component (12) protruding from the end wall (37). The propulsion module (1) includes first and second reinforcement elements (39, 40).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to the field of motor vehicles, and more particularly to a propulsion module for a hybrid vehicle or an electric vehicle.

Background Art

[0002] From the prior art, a propulsion module for a hybrid vehicle or an electric vehicle is known, which includes an electric motor, a reduction gear that receives torque supplied by the rotor of the electric motor, and a differential device that distributes the torque of the reduction gear to two half-shafts of a vehicle axle to rotate the two half-shafts at different speeds. The reduction gear includes an input shaft that is coaxial with and rotationally coupled to the rotor shaft of the electric motor, and an intermediate shaft. The intermediate shaft meshes with the input shaft via a certain set of gears on one hand, and meshes with the differential device via another set of gears on the other hand. The differential device includes two spline output hubs each of which is intended to be fixed to one of the two half-shafts of the vehicle axle respectively. The electric motor is housed in a motor case. On the one hand, the reduction gear and the differential device are housed in a transmission case. The transmission case includes two shells fixed to each other. The motor case is arranged concentrically with respect to the axis of the rotor and protrudes from an end wall of one of the two shells. As a result of such a configuration, the motor case may protrude from the transmission case and / or deform with respect to the transmission case. This makes it easy to cause defects in the alignment and parallelism of the above-mentioned shafts. In particular, it is easy to cause defects in the relative parallelism between the input shaft and the intermediate shaft of the reduction gear. The inventors of the present case have found that such defects in alignment and parallelism cause undesirable noise and vibration in the gear set of the reduction gear, particularly in the set of gears that transmit torque between the input shaft and the intermediate shaft of the reduction gear.

Summary of the Invention

[0003] Therefore, one idea of ​​the present invention is to propose the above-described type of propulsion module in which undesirable noise and vibration are limited.

[0004] To achieve this, according to the first aspect, the present invention is - A propulsion module for a vehicle comprising a motor case having a motor housing intended to house an electric motor, and a transmission case intended to receive a reduction gear and a differential, wherein the motor case and the transmission case are connected to each other, - The motor case is a first cylindrical housing having an axis X, and the first cylindrical housing is intended to receive a first guide bearing for guiding the rotor shaft of the electric motor, and the motor housing is positioned in the axial direction between the first cylindrical housing and the transmission case. - The transmission case comprises first and second openings aligned with each other along an axis Z parallel to the axis X, each of the first and second openings being capable of and intended to allow a wheel drive shaft to pass through, and the transmission case further comprises first and second shells fixed to each other along a fixed interface extending in the interface plane, the first shell having an end wall having the first opening and an end wall adjacent to the motor case, - The motor case includes a cylindrical component that protrudes from the end wall coaxially with the axis X around the axis X, - The propulsion module comprises first and second reinforcing elements positioned on both sides of a central plane including axes X and Z, wherein the first reinforcing element connects at least a first zone of the first shell to the first zone of the motor case, and the second reinforcing element connects at least a second zone of the first shell to the second zone of the motor case. - The first and second zones of the first shell are located radially outward of a circle passing through axis Z and the first opening and centered on axis X, - The first and second zones of the motor case are positioned at an axial distance greater than 50% of d1 from the interface plane, where d1 is the axial distance between the interface plane and the first cylindrical housing. We provide a propulsion module.

[0005] Therefore, the presence of the first and second reinforcing elements increases the rigidity of the connection between the motor case and the transmission case. This limits defects, particularly in the parallelism between the shafts of the reduction gear, thereby limiting undesirable noise and vibration that can easily occur with the gear wheels of the reduction gear.

[0006] Furthermore, the reinforcing elements are connected to the most rigid zones of the transmission case and the motor case. This further improves the rigidity of the connection between the motor case and the transmission case.

[0007] According to various embodiments, such a propulsion assembly may have one or more of the following features:

[0008] According to one embodiment, the second shell has an end wall having the second opening.

[0009] According to one embodiment, the first and second zones of the motor case are positioned at an axial distance greater than 70% of the axial distance d1, preferably greater than 80%, from the interface plane.

[0010] According to one embodiment, the first and second zones of the motor case are positioned at an axial distance of less than 130% of the axial distance d1 from the interface plane.

[0011] According to one embodiment, the first and second zones of the first shell are located on the end walls of the first shell.

[0012] According to another embodiment, the first and second zones of the first shell are adjacent to the end walls of the first shell. Thus, the reinforcing element is fixed to the rigid zone of the first shell.

[0013] According to one embodiment, the first reinforcing element is equipped with a dedicated reinforcing material.

[0014] According to one embodiment, the first reinforcing element is separate from the fixed flange or housing located on the first shell.

[0015] According to one embodiment, the first reinforcing element has a certain thickness.

[0016] According to one embodiment, the first reinforcing element comprises a reinforcing member selected from ribs and brackets. This type of reinforcing member is particularly effective in limiting the deformation of the motor case relative to the end wall of the first shell.

[0017] According to one embodiment, each bracket has a bar-like overall shape. Each bar can be connected by its end to a first zone of a first shell and a first zone of a motor case. According to one embodiment, the reinforcing member is a rib having a first edge and a second edge, the first edge being connected to the end wall of the first shell in at least the first zone of the first shell, and the second edge being connected to the cylindrical component of the motor case in at least the first zone of the motor case.

[0018] In one embodiment, the first edge of the rib is connected to the end wall of the first shell along its entire length.

[0019] According to one embodiment, the second edge of the rib is connected to a cylindrical component of the motor case along its entire length.

[0020] According to one embodiment, the first shell and the cylindrical component of the motor case are formed as a single (one-piece) component. In such a case, one of the end walls of the first shell and the end wall of the motor case may be made to coincide, and a partition wall may be formed between the inner space of the motor housing and the transmission case.

[0021] According to one embodiment, the first shell and the cylindrical component of the motor case are formed from two separate components integrally fixed by fasteners.

[0022] According to one embodiment, the motor case is a second component fixed to a cylindrical component protruding from the end wall of the first shell, and includes a second component having an end wall that closes the motor housing at the opposite end of the transmission case.

[0023] According to one embodiment, the first and second zones of the motor case extend to the end wall of the second component of the motor case.

[0024] According to one embodiment, the rib is formed together with the first shell and the cylindrical component of the motor case during their casting. Therefore, such a rib can be manufactured in a simple manner during the casting of the first shell and the cylindrical component of the motor case.

[0025] According to another embodiment, the rib is welded to the first shell and the cylindrical component along the first edge and the second edge.

[0026] According to one embodiment, the reinforcing member extends in a plane parallel to the axes X and Z. Such an orientation of the reinforcing member can provide greater resistance to deformation of the motor case with respect to the end wall of the first shell.

[0027] According to one embodiment, the reinforcing member is a bracket including a central bar and two fixing tabs respectively fixed to the first zone of the first shell and the first zone of the motor case.

[0028] According to one embodiment, the fixed tab is fixed to the first shell and the motor case by a fastener. According to another embodiment, the fixed tab is fixed to the first shell and the motor case by welding.

[0029] According to one embodiment, the second reinforcing element includes a casing for housing a power electronics device, the casing being fixed to the second zone of the first shell by a first mounting support and to the second zone of the motor case by a second mounting support. Thus, the rigidity of such a casing is utilized to strengthen the rigidity of the connection between the motor case and the transmission case.

[0030] According to one embodiment, the power electronics device is an inverter / rectifier type voltage converter electrically connected between a power storage unit of a vehicle and an electric motor.

[0031] According to one embodiment, the second reinforcing element includes a support element intended to provide support for the propulsion module with respect to the chassis of the vehicle, the support element including a plate fixed to the second zone of the first shell by a first mounting support and to the second zone of the motor case by a second mounting support, and an elastomeric block fixed to the plate and intended to be placed directly or indirectly on the chassis of the vehicle. Thus, the rigidity of such a support element is utilized to strengthen the rigidity of the connection between the motor case and the transmission case.

[0032] According to one embodiment, the second mounting support is fixed to an end wall of a second part of the motor case.

[0033] According to one embodiment, the second reinforcing element is separate from a fixed flange or housing arranged on the first shell.

[0034] According to one embodiment, the second reinforcing element has a certain thickness.

[0035] According to another embodiment, the second reinforcing element comprises reinforcing material selected from ribs and brackets.

[0036] According to one embodiment, each bracket has a bar-like overall shape. Each bar can be connected by its end to a second zone of a first shell and a second zone of a motor case. According to one embodiment, the rib of the second reinforcing element has a first edge and a second edge, the first edge being connected to the end wall of the first shell in at least the second zone of the first shell, and the second edge being connected to the cylindrical component of the motor case in at least the second zone of the motor case.

[0037] According to one embodiment, the ribs of the second reinforcing element are formed together with the cylindrical parts of the first shell and the motor case during their casting.

[0038] According to one embodiment, the rib of the second reinforcing element extends in a plane parallel to the axes X and Z.

[0039] According to one embodiment, the bracket of the second reinforcing element comprises a central bar and two fixing tabs fixed to the second zone of the first shell and the second zone of the motor case, respectively.

[0040] According to one embodiment, the first and second reinforcing elements are firmly connected to each other by connecting elements located at least partially, preferably entirely, in a zone located outside a rotating right cylindrical cylinder centered on axis X, the rotating right cylindrical cylinder having a radius corresponding to the distance separating axis X and axis Z along a straight line perpendicular to axis X and axis Z.

[0041] According to one embodiment, when viewed from a plane perpendicular to axes X and Z, the connecting element has a curved or curved shape, particularly a circular shape.

[0042] According to one embodiment, the connecting element has a substantially constant height in the axial dimension.

[0043] According to one embodiment, the connecting element has a height substantially equal to that of the first and second reinforcing elements in the axial dimension.

[0044] According to one embodiment, the connecting element has a certain thickness.

[0045] According to one embodiment, the connecting element continuously connects the first reinforcing element and the second reinforcing element. In other words, the connecting element is separate from the fixed flange or housing located on the first shell.

[0046] According to one embodiment, when viewed from a plane perpendicular to the axis X and the axis Z, the first and second reinforcing elements are formed from the same single rib, for example, having a curved portion.

[0047] According to one embodiment, the single rib has a substantially constant height in the axial dimension.

[0048] According to one embodiment, the single rib has a certain thickness.

[0049] According to one embodiment, the single rib is continuous. In other words, the single rib is separate from the fixed flange or housing located on the first shell.

[0050] According to one embodiment, the curved portion has a substantially circular shape when viewed from a plane perpendicular to axes X and Z.

[0051] According to one embodiment, the rib is U-shaped with two branches. The two branches form first and second reinforcing elements, respectively, and are located on both sides of the central plane. The two branches merge behind an opening formed in the end wall of the first shell.

[0052] According to one embodiment, the first reinforcing element is in contact with (preferably fixed to) the motor case over a distance exceeding 45% of the axial distance separating the first zone of the motor case from the interface plane.

[0053] Preferably, the first reinforcing element is in contact with (preferably fixed to) the motor case over the entire axial distance separating the first zone of the motor case from the interface plane.

[0054] According to one embodiment, the first reinforcing element is in contact with (preferably fixed to) the first shell over a radial distance of more than 45% of the distance separating the first zone of the first shell from the motor case.

[0055] Preferably, the first reinforcing element is in contact with (preferably fixed to) the first shell over the entire radial distance separating the first zone of the first shell from the motor case.

[0056] According to one embodiment, the propulsion module is - An electric motor housed in the motor case, comprising a stator and a rotor shaft whose rotation around the axis X is guided by the first and second guide bearings, - A differential mounted inside the transmission case so as to rotate about the shaft Z, comprising two hubs intended to be connected to the first and second half-shafts, - A reduction gear comprising: an input shaft rotatably connected to the rotor shaft and guided to rotate around the axis X within the transmission case; and an intermediate shaft guided to rotate around an axis Y parallel to the axis X within the transmission case, wherein the intermediate shaft meshes with the input shaft via a first set of gears and meshes with the differential via a second set of gears, It also has the following features.

[0057] According to one embodiment, the differential includes a differential box whose rotation is guided within a casing around an axis Z, two planetary pinions mounted in the differential box so as to rotate around an axis W perpendicular to axis Z, and two sun gears rotatable around axis X, each meshing with the two planetary pinions and each intended to directly or indirectly drive the rotation of a half-shaft.

[0058] The present invention will be better understood and other purposes, details, features, and advantages will become clearer from the following description of several specific embodiments of the invention, which are provided only as non-limiting examples with reference to the accompanying drawings. [Brief explanation of the drawing]

[0059] [Figure 1] Figure 1 is a schematic diagram of the propulsion module. [Figure 2] Figure 2 is a detailed view of the reduction gear and differential gear of the propulsion module shown in Figure 1. [Figure 3] Figure 3 is a partial perspective view of a propulsion module equipped with reinforcing material according to the first embodiment. [Figure 4] Figure 4 is another perspective view of the propulsion module shown in Figure 3. [Figure 5] Figure 5 is a partial perspective view of a propulsion module equipped with reinforcing material according to the second embodiment. [Figure 6] Figure 6 is another perspective view of the propulsion module shown in Figure 5. [Figure 7] Figure 7 is a partial perspective view of a propulsion module equipped with reinforcing material according to the third embodiment. [Figure 8] Figure 8 is a partial perspective view of a propulsion module equipped with reinforcing material according to the fourth embodiment. [Figure 9] Figure 9 is a partial perspective view of a propulsion module equipped with reinforcing material according to the fifth embodiment. [Modes for carrying out the invention]

[0060] In this specification and in the claims, the terms “outside” and “inside,” and the orientations “axial” and “radial” may be used to indicate elements of a propulsion module according to the definitions provided herein. By convention, the axis of rotation X of the rotor shaft 9 of the electric motor 2 defines the “axial” orientation. The terms “outside” and “inside” are used to define the relative position of one element to another with respect to the axis X. Thus, an element closer to the axis is referred to as “inside” with respect to an outer element located on the periphery in the radial direction.

[0061] A propulsion module 1 for an electric or hybrid vehicle will be described in reference to Figure 1. The propulsion module 1 comprises an electric motor 2, a reduction gear 3, and a differential gear 4. Thus, in the propulsion module 1, the electric motor 2 generates torque, the reduction gear 3 increases the torque, and the differential gear 4 distributes the torque to two half-shafts, causing them to rotate at different speeds.

[0062] According to one embodiment, such a propulsion module 1 is intended for hybrid vehicles. Therefore, the above-described propulsion module 1 can, for example, transmit torque from the electric motor 2 to the rear axle or front axle of the vehicle. In contrast, another propulsion module 1 equipped with another motor / engine, such as a combustion engine, can generate torque and transmit it between the other motor / engine and the two half-shafts of the other axle of the vehicle.

[0063] As shown in Figure 1, the propulsion module 1 comprises a motor case 5 housing an electric motor 2 and a transmission case 6 housing a reduction gear 3 and a differential gear 4. The transmission case 6 and the motor case 5 are fixed to each other.

[0064] The electric motor 2 comprises a stator 7 and a rotor 8, which are fixedly mounted inside the motor case 5. The rotor 8 has a rotor shaft 9 mounted inside the motor case 5 so as to be rotatable about axis X. The rotor shaft 9 is guided by a first rolling bearing 10 and a second rolling bearing 11. Each of these bearings is located near one end of the rotor shaft 9. According to another embodiment (not shown), the rotor shaft 9 is guided by its rotation in the motor case 5 by the first rolling bearing 10 alone. Alternatively, the rotor shaft 9 may be guided by more than two rolling bearings, for example, three.

[0065] The motor case 5 substantially has the shape of a rotating cylinder concentric with the rotation axis X of the rotor shaft 9. In the illustrated embodiment, the motor case 5 comprises two cylindrical parts 12 and 13, respectively. The parts 12 and 13 are fixed to each other and each has end walls 14 and 15 to close off the inner space of the motor case 5. The first rolling bearing 10 and the second rolling bearing 11 are mounted in the first cylindrical housing 17 and the second cylindrical housing 16, respectively. The first cylindrical housing 17 and the second cylindrical housing 16 are formed in the end walls 15 and 14 of the two parts 13 and 12 of the motor case 5, respectively.

[0066] Furthermore, the transmission case 6 comprises two integrally fixed shells 18, 19. Each shell 18, 19 comprises end walls 37, 38 facing the end walls 37, 38 of the other shell 18, 19, and a skirt extending parallel to the axis X from around the corresponding end walls 37, 38. The skirt of each shell 18, 19 comprises fixing flanges 20, 21 intended to be positioned in contact with the fixing flange of the other shell 18, 19. Each of the fixing flanges 20, 21 has an orifice through which fasteners 22 such as bolts can pass, thereby allowing the two fixing flanges 20, 21 to be fixed integrally. Thus, the fixing flanges 20, 21 define a fixing interface. The fixing interface extends into an interface plane P1 perpendicular to the axis X of the rotor shaft 9 of the electric motor 2. In a modified embodiment not shown, one and / or the other of the two shells 18, 19 may comprise a plurality of integrally joined components.

[0067] In the illustrated embodiment, the cylindrical component 12 of the motor case 5 and the adjacent shell 18 of the transmission case 6 are formed as a single component. In this case, as shown in Figure 1, the end wall 14 of the motor case 5 is formed by the end wall 37 of the first shell 18. In other words, the end wall of the motor case 5 forms a partition wall between the motor housing space and the inner space of the transmission case 6.

[0068] However, in another embodiment not shown, the motor case 5 component 12 and the adjacent shell 18 are formed as two separate components that are fastened to each other using fasteners.

[0069] The reduction gear 3 shown in Figures 1 and 2 comprises an input shaft 23 and an intermediate shaft 24, which are mounted to be rotatable inside the transmission case 6. The input shaft 23 and the rotor shaft 9 are coaxial and connected to each other so as to rotate integrally. According to one embodiment, the input shaft 23 and the rotor shaft 9 are connected to each other by a spline coupling 29. Thus, one of the two shafts has a spline male, which is pressed into the spline female of the other shaft. The input shaft 23 and the intermediate shaft 24 are guided to rotate inside the transmission case 6 by a pair of rolling bearings. One of the rolling bearings is housed in a cylindrical housing on the end wall 37 of one shell 18, and the other is housed in a cylindrical housing on the end wall 38 of the other shell 19. The intermediate shaft 24 is mounted inside the transmission case 6 so as to be rotatable about an axis Y parallel to axis X.

[0070] The input shaft 3 has one gear wheel 25, and the intermediate shaft 24 has two gear wheels 26 and 27. The gear wheel 25 of the input shaft 3 meshes with the larger gear wheel 26 of the intermediate shaft 27, and the smaller gear wheel 27 of the intermediate shaft 24 meshes with the gear wheel 28 of the differential 4. Thus, the reduction gear 3 generates a gear ratio of less than 1 from the electric motor 2 to the differential 4. This allows the torque delivered to the half-shaft to be higher than the torque delivered to the output of the electric motor 2.

[0071] Furthermore, as shown in Figure 2, the differential 4 includes a differential box 30 mounted inside the transmission case 6 so as to be rotatable about an axis Z parallel to axes X and Y. The differential box 30 is connected to the gear wheel 28 of the differential 4 so as to rotate integrally with it. The differential 4 also includes two planetary pinions 31 and 32 mounted inside the differential box 30 so as to rotate about an axis W perpendicular to axis Z, and two sun gears 33 and 34. The two sun gears 33 and 34 each have bevel gear teeth that mesh with complementary bevel gear teeth belonging to the two planetary pinions 31 and 32. The two sun gears 33 and 34 are also rotatable about axis Z. Each of the sun gears 33 and 34 has a spline hub intended to directly or indirectly drive the rotation of one of two half-shafts (not shown) of the vehicle's axle. As shown in Figure 1, the openings 35 and 36 formed in the respective end walls 37 and 38 of the two shells 18 and 19 each have a wheel drive shaft passing through them. The wheel drive shaft corresponds to a spline hub of one of the sun gears 33 and 34, a half shaft, or any other component that transmits power between the differential 4 and the wheels. Thus, the openings 35 and 36 allow a half shaft located outside the transmission case 6 to be connected to the differential 4, which is itself housed inside the transmission case 6.

[0072] In one embodiment (not shown), the gear wheel 28 and differential box 30 of the differential gear 4 are connected to each other by a coupling device having a coupled position and a discoupled position. In the coupled position, the coupling device enables the transmission of torque between the gear wheel 28 and the differential box 30. In the discoupled position, the transmission of torque between the gear wheel 28 and the differential box 30 is interrupted. Therefore, such a coupling device allows the electric motor 2 to be coupled to the two half-shafts of the axle so that the vehicle can be propelled by the electric motor 2, or, when the electric motor 2 is not in use, the electric motor 2 can be discoupled from the half-shafts of the axle so that the electric motor 2 and the reduction gear 3 do not generate resistance torque (drag).

[0073] In another embodiment (not shown), the propulsion module 1 includes a second motor located on the other side of the transmission case 6. Thus, this second motor is housed in a second motor case that protrudes from the end wall 38 of the second shell 19. In this way, the rotor shaft of the second motor meshes with the end of the reduction gear input shaft 23 opposite to the end that meshes with the rotor shaft 9 of the first electric motor 2.

[0074] In favorable modifications, in such cases, reinforcing elements similar to those described below may also be used to reinforce the connection between the end wall 38 of the second shell 19 and the second motor case.

[0075] A propulsion module according to the first embodiment, which is provided with two reinforcing elements configured to strengthen the rigidity of the connection between the motor case 5 and the transmission case 6, will be described in reference to Figures 3 and 4. This makes it possible to limit defects in the parallelism between the rotor shaft 9 and the intermediate shaft 24 of the reduction gear 3, and consequently between the input shaft 23 and the intermediate shaft 24 of the reduction gear 3, thereby reducing vibration.

[0076] In this embodiment, two reinforcing elements are formed from dedicated reinforcing material. More specifically, the reinforcing material is ribs 39, 40 that protrude from the end walls 37 of the shells 18 of the motor case 5 and the transmission case 6. In this example, the ribs 39, 40 are formed together with the integral elements that form the cylindrical part 12 of the motor case 5 and the adjacent shell 18 of the transmission case 6 during their casting. However, according to another embodiment, the ribs 39, 40 are each composed of metal plates welded to the motor case 5 and the transmission case 6.

[0077] The two ribs 39 and 40 extend on both sides of the plane P2 containing axes X and Z. Additionally, the ribs 39 and 40 extend in planes parallel to axes X and Z, respectively. Thus, this arrangement provides greater resistance to forces that tend to deform the motor case against the end walls 37 of the shell 18. As can be seen further in Figure 2, the two ribs 39 and 40 are substantially oriented radially with respect to axis X.

[0078] Each rib 39, 40 has a first edge 42 and a second edge 43. The first edge 42 connects to the end wall 37 of the shell 18 along its entire length. The second edge 43 connects to the cylindrical component 12 of the motor case 5 along its entire length. In the illustrated embodiment, the first edge 42 and the second edge 43 of the ribs 39, 40 are perpendicular to each other. As shown in Figure 3, the edges 42 of the ribs 39, 40 extend to a zone of the end wall 37 located outside the surface of the end wall 37, which is defined by a circle C passing through axis Z and centered on axis X, as shown by a dotted line in Figure 3. Therefore, the ribs 39, 40 connect to the most rigid zone of the end wall 37, because the rigidity of the end wall 37 tends to increase with increasing distance from the motor case 5 and toward the periphery of the end wall 37 and toward the fixed flange 21 of the shell 18.

[0079] Furthermore, as shown in Figure 4, the second edges 43 of the ribs 39 and 40 extend away from the end wall 37 of the shell 18 to a zone of the motor case 5 located at an axial distance d2 from the interface plane P1. The axial distance d2 is greater than 50%, preferably greater than 70%, and advantageously between 80 and 130%, of the axial distance d1 (shown in Figure 1) between the interface plane P1 and the first cylindrical housing 17 of the motor case 5, i.e., the housing that receives the first rolling bearing 10 that guides the rotation of the rotor shaft 9. Thus, the ribs 39 and 40 also connect to the most rigid zone of the motor case 5, because the rigidity of the motor case 5 tends to increase as it approaches the end wall 15 of the motor case 5.

[0080] Figures 5 and 6 show the propulsion module 1 according to the second embodiment.

[0081] In this embodiment, the two reinforcing elements positioned on either side of the plane P2 are composed of a single reinforcing member formed by a rib 41 in this example. The rib 41 is formed in this example together with the integral element forming the cylindrical part 12 of the motor case 5 and the adjacent shell 18 of the transmission case 6 during their casting. However, according to an alternative embodiment, the rib 41 is composed of a metal plate welded to the motor case 5 and the transmission case 6. According to the illustrated embodiment, the rib 41 is U-shaped with two branches. The two branches form two reinforcing elements and are positioned on either side of the plane P2. The curved portion of the rib 41 firmly connects the branches. The curved portion is positioned behind the opening 35 formed in the end wall 37, i.e., on the opposite side of the opening 35 relative to the motor case 5. The rib 41 has a first edge 42. The first edge 42 connects to the end wall 37 of the shell 18 along its entire length. Since the rib 41 passes around the opening 35, each of these branches extends to a zone of the end wall 37 located outside the surface of the end wall 37, as in the embodiments of Figures 3 and 4, which is defined by a circle C passing through axis Z and centered on axis X.

[0082] Furthermore, as shown in Figure 6, each branch of the rib 41 has an edge 43. The edge 43 connects to the cylindrical component 12 of the motor case 5 along its entire length. As in the embodiments of Figures 3 and 4, the edge 43 of the branch of the rib 41 extends to a zone of the motor case 5 located at an axial distance d3 from the interface plane P1, away from the end wall 37 of the shell 18. The axial distance d3 is greater than 50%, preferably greater than 70%, and advantageously between 80% and 130% of the axial distance d1.

[0083] Figure 7 shows a propulsion module 1 according to a third embodiment, which differs from the embodiments described above in terms of the structure of the two reinforcing elements. Here, the reinforcing elements comprise two reinforcing members formed from two metal brackets 44, 45 extending on both sides of a plane P2. Each bracket 44, 45 comprises a straight central bar 46 and two bent fixing tabs 47, 48 positioned at the ends of the brackets 44, 45. The central bar 46 is inclined with respect to axes X and Z. The two fixing tabs 47, 48 are fixed to the end wall 37 of the shell 18 and the cylindrical component 12 of the motor case 5, respectively. In the illustrated embodiment, the fixing tabs 47, 48 are fixed to the transmission case 6 and the motor case 5 by fasteners such as screws that pass through openings formed in the fixing tabs 47, 48 and the motor case 5 and the transmission case 6. However, in another alternative or complementary embodiment, the fixing tabs 47, 48 are welded to the motor case 5 and the transmission case 6. The fixing tab 47 is fixed to a zone on the end wall 37 of the shell 18, which passes through axis Z and is located outside the edge C centered on axis X. Furthermore, the fixing tab 48 is fixed to a zone on the motor case 5 located at an axial distance d4 from the interface plane P1, away from the end wall 37 of the shell 18. The axial distance d4 is greater than 50%, preferably greater than 70%, and advantageously between 80% and 130% of the axial distance d1.

[0084] Figure 8 shows a propulsion module 1 according to a fourth embodiment. As in the embodiments described above, the propulsion module 1 comprises two reinforcing elements positioned on both sides of the plane P2. One of the reinforcing elements is formed from a dedicated reinforcing material in the shape of a rib 39. This rib 39 has a structure similar to that described above in relation to Figures 3 and 4. In contrast, the other reinforcing element is not formed from a dedicated reinforcing material, but from a casing 49 that houses power electronics equipment, such as an inverter / rectifier type voltage converter.

[0085] Such a voltage converter electrically connects the electric motor 2 to a power storage unit (not shown) of the vehicle. The voltage converter is used to power the electric motor 2 by converting the DC voltage from the power storage unit to AC voltage when the electric motor 2 is operating in vehicle propulsion mode. The voltage converter can also rectify the AC voltage generated at the terminals of the electric motor 2's stator so as to charge the power storage unit when the electric motor 2 is operating in generator mode.

[0086] As shown in Figure 8, the casing 49 extends in a plane parallel to axes X and Z. The casing 49 is fixed to the shell 18 of the transmission case 6 on the one hand and to the motor case 5 on the other hand. More specifically, the casing 49 is fixed to the motor case 5 via a first mounting support 51 fixed to the end wall 15 of the motor case 5. Furthermore, the casing 49 is fixed to the shell 18 via second and third mounting supports 50, 52 fixed to the skirt and / or end wall 37 of the shell 18.

[0087] Therefore, the casing 49 having mounting supports 50, 51, and 52 forms a reinforcing element that, similar to the reinforcing member in the previous embodiment, is fixed on the one hand to a zone of the transmission case 6 located outside the circle C, and on the other hand to a zone of the motor case 5 located at an axial distance d5 from the interface plane P1. The axial distance d5 is greater than 50% of the axial distance d1, preferably greater than 70%, and less than 130%.

[0088] Figure 9 shows a propulsion module according to the fifth embodiment. This embodiment differs from the fourth embodiment shown in Figure 8 in that the reinforcing elements, which are not formed from dedicated reinforcing materials, are formed by support elements 53 intended to support the propulsion module 1 on the vehicle chassis, rather than the casing 49 shown in Figure 8. In the illustrated embodiment, the support element 53 comprises a plate 54 and an elastomer block 55. The elastomer block 55 is fixed to the plate 54 and is intended to be mounted on a frame fixed to the vehicle chassis. The plate 54 extends in a plane parallel to axes X and Z. Furthermore, the support element 53 is fixed on one side to the shell 18 of the transmission case 6 and on the other side to the motor case 5. In the illustrated embodiment, the support element 53 is fixed to the transmission case 6 and the motor case 5 by mounting supports 50, 51, and 52 having similar features to those described above in relation to Figure 8.

[0089] Although the present invention has been described in relation to several specific embodiments, it is quite clear that the present invention is by no means limited thereto and comprises all technical equivalents of the means described and combinations thereof where they fall within the scope of the present invention.

[0090] The use of the verbs "have," "comprise," and "include," and their conjugations, does not preclude the existence of elements or steps other than those described in the claims.

[0091] In the claims, reference numerals in parentheses should not be construed as limiting the scope of the claims.

Claims

1. A propulsion module (1) for a vehicle, comprising a motor case (5) having a motor housing intended to accommodate an electric motor (2), and a transmission case (6) intended to receive a reduction gear (3) and a differential gear (4), said motor case (5) and said transmission case (6) being connected to each other, - the motor case (5) has a first cylindrical housing (17, 16) with an axis X, intended to receive first guide bearings (10, 11) for guiding a rotor shaft (9) of the electric motor (2), the motor housing being arranged axially between the first cylindrical housing (17) and the transmission case (6); the transmission case (6) comprises first and second openings (35, 36) aligned with one another along an axis Z parallel to the axis X, each of the first and second openings (35, 36) being capable and intended to allow a wheel drive shaft to pass therethrough, the transmission case further comprising first and second shells (18, 19) fixed to one another along a fixing interface extending in an interface plane (P1), the first shell (18) having an end wall adjacent to the motor case and having the first opening (35); - said motor case (5) comprises a cylindrical part (12) projecting from said end wall (37) around and coaxial with the axis X; - said propulsion module (1) comprises first and second reinforcing elements (39, 40; 41; 44, 45; 49; 53) arranged on either side of a mid-plane (P2) containing the axes X and Z, said first reinforcing elements (39, 44) connecting at least a first zone of said first shell (18) with a first zone of said motor case (5) and said second reinforcing elements (40, 45, 49, 53) connecting at least a second zone of said first shell (18) with a second zone of said motor case (5); - said first and second zones of said first shell (18) are arranged radially outside a circle passing through said axis Z and said first opening (35) and centred on said axis X; - the first and second zones of the motor case (5) are arranged at axial distances (d2, d3, d4, d5) from the interface plane (P1) that are greater than 50% of d1, d1 being the axial distance between the interface plane (P1) and the first cylindrical housing (17); Propulsion module (1).

2. 2. A propulsion module (1) according to claim 1, wherein the second shell (19) has an end wall (38) with the second opening (36).

3. 2. The propulsion module (1) according to claim 1, wherein the first reinforcing element comprises a reinforcing material selected from a rib (39, 41) and a bracket (44).

4. 4. A propulsion module (1) according to claim 3, wherein the reinforcement is a rib (39, 41) having a first edge (43) and a second edge (42), the first edge (43) being connected to the end wall (37) of the first shell (18) at least in the first zone of the first shell (18), and the second edge (42) being connected to the cylindrical part of the motor case (5) at least in the first zone of the motor case (5).

5. 2. A propulsion module (1) according to claim 1, wherein the first shell (18) and the cylindrical part (12) of the motor case (5) are formed as a single piece.

6. 4. The propulsion module (1) according to claim 3, wherein the ribs (39, 41), the first shell (18) and the cylindrical part (12) of the motor case (15) are a single cast part.

7. 4. The propulsion module (1) according to claim 3, wherein the stiffeners extend in planes parallel to the X and Z axes.

8. The propulsion module (1) according to claim 3, wherein the stiffener is a bracket (44).

9. 4. The propulsion module (1) according to claim 3, wherein the stiffener is a bracket (44) having a central bar (46) and two fixing tabs (47, 48) fixed to the first zone of the first shell (18) and the first zone of the motor case (5), respectively.

10. 2. A propulsion module (1) according to claim 1, wherein the second reinforcing element comprises a casing (49) for housing a power electronics device, the casing (49) being fixed to the second zone of the first shell (18) by a first mounting support (51) and to the second zone of the motor case (5) by a second mounting support (50).

11. 2. The propulsion module (1) according to claim 1, wherein the second reinforcing element comprises a support element (53) intended to provide support for the propulsion module (1) relative to the chassis of the vehicle, the support element (53) comprising a plate (54) fixed to the second zone of the first shell (18) by a first mounting support (51) and to the second zone of the motor case (5) by a second mounting support (50), and an elastomer block (55) fixed to the plate (54), the elastomer block (55) intended to be placed directly or indirectly on the chassis of the vehicle.

12. 2. The propulsion module (1) according to claim 1, wherein the second reinforcing element comprises a reinforcing material selected from a rib (41) and a bracket (45).

13. 2. A propulsion module (1) according to claim 1, wherein the first and second reinforcing elements are rigidly connected to each other by connecting elements located at least partially in a zone located outside a right circular cylinder of revolution centered on the axis X and having a radius corresponding to the distance separating the axes X and Z along a line perpendicular to the axes X and Z.

14. 2. A propulsion module (1) according to claim 1, wherein, when viewed in a plane perpendicular to the axis X and the axis Z, the first and second reinforcing elements are formed from the same single rib (41), for example having a curved portion.

15. an electric motor (2) housed in said motor case (5), said electric motor (2) having a stator (7) and a rotor shaft (9) whose rotation about said axis X is guided by said first and second guide bearings (10, 11); a differential (4) mounted to rotate about said axis Z inside said transmission case (6), said differential (4) comprising two hubs intended to be coupled respectively to first and second half shafts; a reduction gear (3) comprising an input shaft (23) rotationally coupled to the rotor shaft and guided to rotate about the axis X inside the transmission case (6), and an intermediate shaft (24) guided to rotate about an axis Y parallel to the axis X inside the transmission case (6), the intermediate shaft (24) meshing with the input shaft (23) via a first set of gears (25, 26) and meshing with the differential gear (4) via a second set of gears (27, 28); The propulsion module (1) according to any one of claims 1 to 11, further comprising:

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