Powertrain module for an electric motor vehicle, and powertrain comprising two powertrain modules

Abstract

The invention relates to a powertrain module (10) for an electric motor vehicle, comprising: - at least one electric machine (14), - a reduction gear (22) comprising at least one input shaft (24) coupled at least to the at least one electric machine (14), and an output shaft (26) driven by the at least one input shaft (24) and capable of transmitting motive power to at least one wheel of the vehicle, characterized in that: - the at least one electric machine (14) is housed in an electric machine casing (28), - the reduction gear (22) is housed in a reduction gear casing (30), - each electric machine casing (28) is fastened to the reduction gear casing (30), - at least one determined casing (28) among the electric machine casing (28) and reduction gear casing (30) comprises a face (42) for fastening to an element of the vehicle.

Description

[0001] DESCRIPTION

[0002] POWERTRAIN MODULE FOR AN ELECTRIC MOTOR VEHICLE, AND POWERTRAIN COMPRISING TWO POWERTRAIN MODULES

[0003] Technical field of the invention

[0004] The invention relates to a powertrain module for an electric motor vehicle, and to an electric vehicle powertrain comprising such a powertrain module.

[0005] Technical background

[0006] Electric motorization of motor vehicles offers new possibilities for controlling the traction of these vehicles.

[0007] Conventionally, a motor vehicle comprises a thermal engine or an electric machine, which transmits driving power to the wheels of the vehicle successively via a transmission and then a differential which is coupled to each of the wheels of the axle in question. The differential makes it possible to distribute the rotational speed at the input of the latter by distributing the kinetic force, in an adaptive, immediate and automatic manner, to the needs of the vehicle. Thus, it allows the drive wheels coupled at the output of the differential to turn at different speeds when passing through a curve, the wheels located on the outside of the curve turning faster than those located on the inside.

[0008] In the case of a thermal vehicle, the transmission includes a gearbox allowing the rotation speed and torque supplied by the thermal engine at the gearbox input to be adapted to a variable speed and / or torque at the gearbox output and upstream of the differential, the variation in speed then being obtained by the choice of different ratios of this gearbox.

[0009] In the case of an electric vehicle, the transmission generally includes a reducer which makes it possible to bring the speed supplied by the electric machine upstream of the differential into a range of rotation speeds acceptable for it, the variation in the speed upstream of the differential being directly obtained by controlling the rotation speed of the electric machine upstream of the reducer.

[0010] Compared to a thermal engine, an electric machine has an extremely short reaction time and its rotation speed can be controlled very precisely. It is therefore possible to propose for the same axle a powertrain in which the adaptation of the speed of the drive wheels is no longer necessarily carried out by a differential, but by two independent powertrain modules, each comprising at least one electric machine and a reduction gear, and each supplying driving power to one of the wheels of the axle.

[0011] Depending on the vehicle's traction needs, power electronics in this powertrain control each electric machine independently. The rotation speed of each electric machine can therefore be controlled so as to allow the drive wheels coupled to the output of each powertrain module to rotate at different speeds when passing through a curve. In addition, the rotation torque of each electric machine can also be controlled so as to allow the drive wheels coupled to the output of each powertrain module to be driven with a precise torque at each instant depending on the use cases and road grip.

[0012] This ensures that the torque at each wheel is adequately adapted to the vehicle's traction needs. This configuration allows the torque to be controlled and precisely as needed, thereby better distributing the forces within each powertrain module, ensuring greater reliability.

[0013] Such a powertrain module can also be used independently, as part of a tricycle-type vehicle with only one drive wheel.

[0014] For preventive or curative maintenance purposes, it is important to be able to replace the various elements of a powertrain module quickly, i.e. with the greatest possible modularity. This requirement is essential in the context of a powertrain of a motor vehicle axle, for which it is important to be able to replace one or other of the machines or one or other of the reducers quickly in order to limit the overall downtime of the vehicle.

[0015] Summary of the invention

[0016] The invention meets this need by providing a powertrain module of modular design, the elements of which can be disassembled and replaced quickly.

[0017] For this purpose, the invention proposes a powertrain module for an electric motor vehicle comprising:

[0018] - at least one electrical machine,

[0019] - a reducer comprising at least one input shaft coupled at least to said at least one electrical machine and an output shaft, driven by said at least one input shaft, capable of transmitting driving power to at least one wheel of the vehicle.

[0020] According to the invention, this module is characterized in that:

[0021] - said at least one electrical machine is housed in an electrical machine casing,

[0022] - said reducer is housed in a reducer housing,

[0023] - the or each electrical machine casing is fixed to the reducer casing,

[0024] - at least one specific casing among the electrical machine and reducer casings has a face for attachment to an element of the vehicle.

[0025] The invention advantageously makes it possible to separate and remove one or other of the components from the electric machine and the reducer, independently of the other, by removing it from one piece with the housing dedicated to it. The invention thus makes it possible to quickly replace a defective electric machine or reducer with a similar replacement component without having to remove and reassemble the components that are not defective.

[0026] According to other characteristics of the invention:

[0027] - the fixing face is configured to be fixed to a fixing face of a similar determined casing of another powertrain module, said other powertrain module being symmetrical to the powertrain module with respect to a plane of symmetry passing through said fixing face,

[0028] - the fixing face is carried by the casing of said at least one electrical machine,

[0029] - the or each electrical machine casing comprises an external bearing which is received in a bell of the reducer casing, of a shape complementary to said bearing, - the reducer casing comprises at least one opening capable of allowing the passage of an electrical connector, in particular an electrical connection bar, to said at least one electrical machine,

[0030] - each electric machine or reducer casing comprises two respective half-i-electric machine or reducer casings which are joined along assembly faces parallel to the fixing face,

[0031] - the reducer is a three-parallel shaft reducer comprising an input shaft, an intermediate shaft and an output shaft, housed in the reducer housing,

[0032] - the powertrain module comprises a pivoting axis which passes through a wall of the reducer housing perpendicular to the shafts and which is capable of selectively controlling a blocking of said reducer,

[0033] - said pivoting axis comprises a section, internal to said reducer casing, which is capable of controlling, by means of a return mechanism, a transverse finger capable of cooperating with a toothing of at least one notched wheel secured to one of the shafts of the reducer, to selectively block said reducer,

[0034] - said at least one electric machine is cooled inside the electric machine casing by an oil bath and said electric machine casing carries an external oil / coolant exchanger which is fixed to said electric machine casing and which communicates with said oil bath,

[0035] - an oil passage between the interior of the electric machine casing and the external oil / coolant exchanger is formed between the assembly faces of the electric machine half-casings,

[0036] - said electric machine is axial flux.

[0037] The invention also relates to a motor vehicle powertrain, comprising two powertrain modules, as described above, symmetrical and fixed to each other by their fixing faces.

[0038] Another feature of this powertrain is that it has a power control unit attached transversely to both powertrain modules.

[0039] Brief description of the figures

[0040] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

[0041] [Fig. 1] Figure 1 is an axial sectional view of a powertrain module according to the invention;

[0042] [Fig. 2] Figure 2 is an axial sectional view of a powertrain according to the invention;

[0043] [Fig. 3] Figure 3 is a top view of the powertrain of Figure 2;

[0044] [Fig. 4] Figure 4 is a perspective view of the powertrain of Figure 2;

[0045] [Fig. 5] Figure 5 is a sectional view of a powertrain module through plane 5-5 of Figure 1.

[0046] Detailed description of the invention

[0047] Figures 1 and 5 show a powertrain module 10 of an electric motor vehicle, and Figures 2 to 4 show a powertrain group 12 of an electric motor vehicle produced in accordance with the invention. The module 10, the powertrain group 12 and their constituents will be described with reference to the directions of the trihedron "X", "Y", "Z", where "X" designates an axial direction of the shafts of these module 10 and group 12, "Y" designates a first transverse direction of these modules 10 and group 12 and where "Z" designates a second transverse direction of these modules 10 and group 12 perpendicular to the first transverse direction "Y".

[0048] According to the invention, the powertrain module 10 comprises at least one electrical machine 14, in particular an axial flux machine. The electrical machine 14 comprises in particular a rotor 16 and a stator 18. The rotor 16 rotates a shaft 20 of the electrical machine 14. According to the invention, the electrical machine 14 is housed in an electrical machine casing 28 which is specific to the latter. The electrical machine casing 28 carries the stator 18.

[0049] The powertrain module 10 also comprises a reducer 22 comprising at least one input shaft 24 which is coupled to the shaft 20 of the electric machine 14, and an output shaft 26 which is driven, directly or indirectly, by the input shaft 24. This output shaft 26 is capable of transmitting driving power to at least one wheel of the vehicle (not shown).

[0050] According to the invention, the reducer 22 is housed in a reducer casing 30 which is a casing specific to it and contains only this reducer 30 or at least not the electric machine 14. Similarly, the electric machine casing 28 contains only this electric machine 14 or at least does not contain the reducer 22.

[0051] In the example of a powertrain module 10 which has been shown here, the reduction gear is a reduction gear with three parallel shafts comprising the input shaft 24, an intermediate shaft 32 and the output shaft 26, all housed in the reduction gear housing 30. The input shaft 24 carries an input pinion 34 which drives with a first intermediate pinion 36 of the intermediate shaft 32. The intermediate shaft 32 carries a second intermediate pinion 38 which drives with a pinion 40 of the output shaft 26.

[0052] This configuration is not limiting of the invention, and the latter cannot be limited to a reducer with three parallel shafts.

[0053] In the example of a powertrain module 10 which has been shown here, it only comprises one electric machine 14, but it will be understood that this configuration is not limiting of the invention either. Indeed, the invention can be applied to any reducer comprising at least one input shaft 24 and one output shaft 26 and could for example be applied to an epicyclic or planetary reducer comprising two input shafts each coupled to an electric machine, to obtain different variable reduction ratios of this reducer.

[0054] Advantageously, to allow replacement of the electrical machine 14 or the reducer 22, or maintenance operations of these components independently of one another, the or each electrical machine casing 28 is fixed to the reducer casing 30. This configuration therefore advantageously makes it possible to isolate the at least one electrical machine 14 or reducer 22 by extracting it from the module 10 with its associated casing 28 or 30.

[0055] The electric machine casing 28 is fixed to the reduction gear casing 22 by any means. However, in the preferred relationship mode of the invention this fixing is carried out by bolting using screws.

[0056] Furthermore, the module 10 has the advantage that at least one specific casing among the electric machine casing 28 and the reduction casing 30 has a face 42 for attachment to an element of the vehicle.

[0057] In the embodiment shown in FIG. 1, it is the casing 28 of the electric machine 14 which comprises this fixing face 42, the casing 30 of the reducer 22 being fixed to the casing 28 of the electric machine 14 opposite the fixing face 42.

[0058] This fixing face 42 allows, for example, in the case of the use of the powertrain module 10 in a unitary manner, for example for the motorization of a tricycle type vehicle, to fix it directly to a structural element of the vehicle body.

[0059] Advantageously, as illustrated in FIG. 2, the fixing face 42 is configured to be fixed to a fixing face 42' 28 of a similarly determined casing of another powertrain module 10'. This powertrain module 10' is symmetrical to the propellant module 10 with respect to a plane P of symmetry passing through the fixing face 42. It comprises, in the same way as the powertrain module 10, an electric machine 14' and a reducer 22'.

[0060] The assembly of the two powertrain modules 10, 10', symmetrical and fixed to each other by their fixing faces 42, 42', thus defines a powertrain group 12 of a motor vehicle.

[0061] This powertrain 12 has the advantage of being able to be controlled independently in speed and / or torque for each of these electric machines 14, 14', which makes it possible to adapt the traction of the vehicle equipped with it to the curves that the vehicle takes and to the grip conditions encountered by the wheels of this vehicle.

[0062] In the preferred embodiment of the invention, regardless of the number of electrical machines used in a module 10, each electrical machine casing 28 has an external bearing surface 44 which is received in a bell 46 of the reducer casing 30. The bell 46 of the reducer casing 30 is of a shape complementary to the bearing surface 44. This configuration makes it possible, on the one hand, to preposition the casing 28 of the electrical machine 14 in the casing 30 of the reducer 22 before its fixing, and therefore to facilitate its fixing, this only depending on a simple bolting of the casings 28, 30. On the other hand, this configuration makes it possible to limit the axial size in the X direction of the two casings 28, 30.

[0063] Advantageously, as illustrated in FIG. 1, each electric machine casing 28 or 30 of the reducer comprises two respective half i-casings 28a, 28b of the electric machine and two respective half i-casings 30a, 30b of the reducer. The half i-casings 28a, 28b, with respect to the electric machine casing 28, and the half i-casings 30a, 30b with respect to the reducer casing 30, are respectively joined along respective assembly faces 28c, 28d, 30c, 30d which are parallel to the fixing face 42.

[0064] The bearing surface 44 of the casing 28 of the electric machine 14 being received in the bell 46 of the casing 30 of the reducer 22, it is important to be able to electrically supply the electric machine 14 in a simple manner. This is why, as can be seen in FIG. 1, the reducer casing 30, and more particularly the half-casing 30a, comprises at least one opening 48 which is capable of allowing the passage of an electrical connector, in particular an electrical connection bar (not shown) or power bar, to the electric machine 14.

[0065] The electric machine 14 and the reducer 22 are also independent with respect to their lubrication and cooling. For this purpose, here, the electric machine 14 is cooled inside the electric machine casing 28 by an oil bath. As can be seen in Figures 3 and 4 which represent the complete powertrain 12, each electric machine casing 28, 28' 14, 14' carries an external oil / coolant exchanger 50, 50' which is fixed to the corresponding electric machine casing 28, 28' and which communicates with the internal oil bath of each casing 28, 28'. In Figures 3 and 4, the corresponding coolant lines 52 and 52' of the exchangers 50, 50' will be noted.

[0066] Preferably, an oil passage (not shown) between the interior of the electric machine casing 28 and the external oil / coolant exchanger 50 is formed between the assembly faces 28c, 28d of the half i-casings 28a, 28b of the electric machine. In FIG. 3, a boss 54 is seen intended to be crossed by this oil passage.

[0067] Advantageously, as illustrated in Figure 5, each powertrain module 10 comprises a pivoting axis 56 which passes through a wall of the reducer casing 30 perpendicular to the shafts 24, 26, 32. This pivoting axis 56 is driven in rotation by an electric actuator 58 and it comprises a section 60, internal to the reducer casing 30, which is capable of controlling a transverse finger 62 capable of cooperating with a toothing of at least one wheel 62 of the reducer 22. The finger is movable substantially along the Z axis to selectively block said reducer. As can be seen in Figures 1 and 5, the input shaft 24 comprises a notched wheel 64 integral in rotation with the shaft 24 which is capable of receiving between its notches the transverse finger 62. The section 60 of the pivoting axis 56 is capable of actuating by means of a return mechanism 66 a tilting lever 68. This lever 68 is pivotally mounted around an axis parallel to the direction X, and it carries the transverse finger 62.The pivoting of the lever 68 allows the mobility of the finger 62 along the Z axis.

[0068] Each module 10 therefore has an independent parking brake.

[0069] Finally, as can be seen in Figures 3 and 4, the powertrain 12 advantageously comprises a power control unit 70 which is fixed transversely to the two powertrain modules 10, 10'. It is therefore from this control unit 70 that the electrical connection bars or power bars (not shown) passing through the openings 48 originate. This configuration ensures good stability for the power control unit 70 and simple mounting of the power connection bars. Preferably, this control unit 70 is configured to carry out respective and independent control of each of the electrical machines 14, 14'.

[0070] The invention therefore makes it possible to benefit from a powertrain module 10 and a powertrain group 12 of an electric vehicle, simplifying the preventive and curative maintenance operations of its components.

Claims

CLAIMS 1. Powertrain module (10) of an electric motor vehicle comprising: - at least one electric machine (14), - a reducer (22) comprising at least one input shaft (24) coupled at least to said at least one electrical machine (14) and an output shaft (26), driven by said at least one input shaft (24), capable of transmitting driving power to at least one wheel of the vehicle, characterized in that: - said at least one electric machine (14) is housed in an electric machine casing (28), - said reducer (22) is housed in a reducer casing (30), - the or each electric machine casing (28) is fixed to the reducer casing (30), - at least one specific casing (28) among the casings (28) of the electric machine and (30) of the reducer comprises a face (42) for attachment to an element of the vehicle.

2. Electric vehicle powertrain module (10) according to the preceding claim, characterized in that the fixing face (42) is configured to be fixed to a fixing face (42') of a similar determined casing (28') of another powertrain module (10'), said other powertrain module (10') being symmetrical to the powertrain module (10) with respect to a plane (P) of symmetry passing through said fixing face (42).

3. Powertrain module (10) according to one of the preceding claims, characterized in that the fixing face (42) is carried by the casing (28) of said at least one electric machine (14).

4. Powertrain module (10) according to one of the preceding claims, characterized in that the or each casing (28) of an electric machine comprises an external bearing surface (44) which is received in a bell (46) of the reducer casing (30), of a shape complementary to said bearing surface (44).

5. Powertrain module (10) according to the preceding claim, characterized in that the reducer casing (28) comprises at least one opening (48) capable of allowing the passage of an electrical connector, in particular an electrical connection bar, to said at least one electrical machine (14).

6. Powertrain module (10) according to one of the preceding claims, characterized in that each casing (28) of an electric machine or of a reducer (30) comprises two respective half-casings (28a, 28b) of an electric machine or (30a, 30b) of a reducer which are joined along assembly faces (28c, 28d, 30c, 30d) parallel to the fixing face (42).

7. Powertrain module (10) according to one of the preceding claims, characterized in that the reducer (22) is a reducer with three parallel shafts comprising an input shaft (24), an intermediate shaft (32) and an output shaft (26), housed in the reducer housing (30).

8. Powertrain module (10) according to one of the preceding claims, characterized in that it comprises a pivoting axis (56) which passes through a wall of the reducer casing (30) perpendicular to the shafts (24, 26, 32) and which comprises a section (60), internal to said reducer casing (30), which is capable of controlling by means of a return mechanism (66) a transverse finger (62) capable of cooperating with a toothing of at least one notched wheel (64) secured to one of the shafts (24) of the reducer (22), to selectively block said reducer (22).

9. Powertrain module (10) according to one of the preceding claims, characterized in that said at least one electric machine (14) is cooled inside the electric machine casing (28) by an oil bath and in that said electric machine casing carries an external oil / liquid exchanger cooling (50) which is fixed to said electric machine casing (28) and which communicates with said oil bath.

10. Powertrain module (10) according to the preceding claim taken in combination with claim 6, characterized in that an oil passage between the interior of the electric machine casing (28) and the external oil / coolant exchanger (50) is formed between the assembly faces (28c, 28d) of the half i-casings (28a, 28b) of the electric machine. 1 1. Motor vehicle powertrain (12), comprising two powertrain modules (10, 10') according to one of claims 2 to 10, symmetrical and fixed to each other by their fixing faces (42, 42').

12. Motor vehicle powertrain (12), characterized in that it comprises a power control unit (70) fixed transversely to the two powertrain modules (10, 10').

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