ELECTRIC DRIVE WITH TWO COUPLINGS

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to an electric powertrain for an electric or hybrid vehicle, in particular for an electric or hybrid motor vehicle. STATE OF PRIOR ART

[0002] The invention is particularly applicable to hybrid and electric vehicles. The speeds of an electric motor can be high, greater than or equal to 15,000 revolutions per minute, for example, particularly for two-speed electric transmission chains.

[0003] To adapt the speed and torque, the use of electric motors generally requires a transmission with a speed reduction device to achieve the desired output speed and torque levels at each wheel, and a differential to vary the speed between two laterally opposed wheels.

[0004] To adapt to different vehicle operating conditions, clutches are known to be used, allowing the desired reduction ratio to be selected at the speed reduction device. This type of device is disclosed, for example, in document DE102016202723, which describes a transmission system employing relatively complex planetary gear trains. Document WO 2016 120472 A1 discloses a transmission assembly comprising an electric motor and a clutch.

[0005] Application FR1901916, which has not yet been published, proposed a torque transmission device for a vehicle comprising at least one engine, the torque transmission device comprising: a first clutch comprising a first input element suitable for being driven by the engine and a first output element, a torque being transmitted between the first input element and the first output element when the first clutch is closed, a second clutch comprising a second input element suitable for being driven by the engine and a second output element, a torque being transmitted between the second input element and the second output element when the second clutch is closed, a transmission element, a first transmission mechanism arranged to transmit a torque between the first output element and the transmission element, according to a first gear ratio, a second transmission mechanism arranged to transmit a torque between the second output element and the transmission element, according to a second gear ratio different from the first gear ratio,and a connecting element arranged to allow or interrupt mutual rotational drive between the first output element of the first clutch and the transmission member, via the first transmission mechanism.

[0006] Using at least two gear ratios allows for a balance between high starting torque and top speed, thus reducing the time it takes for the vehicle to reach a high speed. Choosing two gear ratios with an electric motor offers a good compromise between transmission complexity, dynamic performance, vehicle fuel consumption, and the size of the electric motor.

[0007] The use of clutches, particularly progressive multi-disc clutches, also helps to ensure user comfort by avoiding abrupt gear changes and noticeable variations in acceleration.

[0008] In addition, the connecting element allows the drive of the output element of the first clutch, and in particular the output friction discs of the first clutch, to be interrupted when the second clutch is closed, which improves energy efficiency by significantly limiting, or even eliminating, the drag torque at the first clutch when the second clutch is closed.

[0009] However, implementing two clutches involves implementing many different parts, which complicates the design and assembly of a powertrain and increases the cost. DESCRIPTION OF THE INVENTION

[0010] The invention aims to overcome the drawbacks of the prior art.

[0011] To achieve this, according to a first aspect of the invention, a transmission assembly is proposed comprising: an electric machine equipped with a rotor capable of rotating around an axis of rotation (X), a housing for the electric machine, enclosing the electric machine, a first clutch intended to drive in rotation a first transmission mechanism, According to the invention, the housing of the electric machine comprises a first tubular portion extending along the axis of rotation (X) and around the axis of rotation (X), the first tubular portion of the housing projecting axially outwards from the housing on a first side of the electric machine, the first clutch being disposed at least in part around the first tubular portion. According to the invention, the first clutch comprises a plurality of friction discs, at least a portion of the friction discs being arranged around the first tubular portion.

[0012] Thus, the casing of the electric machine can contribute to the actuation and / or assembly of the first clutch.

[0013] The transmission assembly may also include one or more of the following characteristics:

[0014] The transmission assembly includes an output member capable of being driven by the rotor either through the first transmission mechanism or through the second transmission mechanism, the first clutch being capable, in a closed state, of transmitting a torque respectively between the rotor and the first transmission mechanism.

[0015] The transmission of torque between the rotor and the first transmission mechanism is interrupted when said first clutch is opened; the second clutch being capable, in a closed state, of transmitting torque respectively between the rotor and the second transmission mechanism, the transmission of torque between the rotor and the second transmission mechanism being interrupted when said second clutch is opened,

[0016] The first clutch is a wet clutch and the first tubular portion includes at least one coolant distribution conduit, said at least one distribution conduit extending axially and opening radially into the friction discs of the first clutch.

[0017] Said at least one distribution conduit opens axially into an axial sector occupied by the friction discs of the first clutch.

[0018] The transmission assembly includes a second clutch for driving a second transmission mechanism in rotation, and the housing of the electric machine includes a second tubular portion extending along the axis of rotation (X), the second tubular portion projecting axially outwards from the housing on a second side of the electric machine axially opposite to the first side, the second clutch being disposed at least in part around the second tubular portion.

[0019] The second clutch comprises a plurality of friction discs, at least some of the friction discs being arranged around the second tubular portion.

[0020] The second clutch is a wet clutch and the second tubular portion includes at least one coolant distribution conduit, said at least one distribution conduit extending axially and opening radially into the friction discs of the second clutch.

[0021] Said at least one distribution conduit opens axially into an axial sector occupied by the friction discs of the second clutch.

[0022] The rotor is mounted to rotate securely on a common input shaft, common to the first and second clutches, a first bearing is radially interposed between the housing of the electric machine and the common input shaft, the first bearing is located relative to the rotor on the side of the first clutch, and a second bearing is radially interposed between the housing of the electric machine and the common input shaft, the second bearing is located relative to the rotor on the side of the second clutch, the distribution conduit of the first tubular portion opening axially in relation to the first bearing and / or the distribution conduit of the second tubular portion opening axially in relation to the second bearing.

[0023] The housing of the electric machine includes a first side wall arranged axially between the rotor and the first clutch and / or the housing of the electric machine includes a second side wall arranged axially between the rotor and the second clutch.

[0024] The first side wall includes at least one fluid supply conduit which extends radially and which communicates with said at least one cooling fluid distribution conduit of the first tubular portion and / or the second side wall includes at least one fluid supply conduit which extends radially and which communicates with said at least one cooling fluid distribution conduit of the second tubular portion.

[0025] The first clutch is actuated by a first actuator which includes a first chamber for containing an actuating fluid and a first movable piston capable of sliding axially in the first chamber, the first chamber being formed in the casing of the electrical machine, and said at least one fluid supply conduit from the first side wall communicating with the first chamber; and / or the second clutch is actuated by a second actuator which includes a second chamber for containing an actuating fluid and a second movable piston capable of sliding axially in the second chamber, the second chamber being formed in the casing of the electrical machine, and said at least one fluid supply conduit from the second side wall communicating with the second chamber.

[0026] The first chamber is arranged radially outside said at least one cooling fluid distribution duct of the first tubular portion.

[0027] The second chamber is arranged radially outside said at least one cooling fluid distribution conduit of the second tubular portion.

[0028] The common input shaft is hollow and the second transmission mechanism includes a connecting shaft extending axially and disposed inside the common input shaft, with rolling elements, such as needles, being interposed between the common input shaft and the connecting shaft, the common input shaft having at least one lubrication conduit communicating with said at least one supply conduit from the first side wall and / or the second side wall.

[0029] Said at least one lubrication channel is open to lubricate the bearing elements. Thus, the bearing elements interposed between the shafts can be lubricated.

[0030] The first transmission mechanism includes a first reduction device and the second transmission mechanism includes a second reduction device connected to the second clutch by the connecting shaft, the first and second reduction devices being located axially on the same side of the electric machine.

[0031] The casing of the electric machine includes a housing and one of the first and second side walls is formed on a cover attached to the housing.

[0032] The casing includes a cylindrical portion in which the electrical machine is housed.

[0033] The lid is attached to the cylindrical portion of the case.

[0034] The cover is mounted in a watertight manner on the case, particularly on its cylindrical portion.

[0035] The other, between the first and second side walls, is formed in one piece with the cylindrical portion of the case and forms a bottom of the case.

[0036] A bearing support is mounted on the first tubular portion and a first load-bearing element is arranged in axial support against this bearing support so as to take up at least part of the axial forces transmitted by the first actuator to the first clutch.

[0037] The first tubular portion is formed in a part of the housing of the electrical machine comprising a wall covering and / or protecting the electrical machine.

[0038] In other words, this wall and the tubular portion are formed as a single unit. In other words, this casing component directly encloses and / or protects the electrical machine, the electrical machine (specifically its rotor or stator) being positioned opposite the wall covering and / or protecting it.

[0039] The first tubular portion and the first side wall are formed from a single piece, particularly in the lid.

[0040] The second tubular section and the second side wall are formed from a single piece.

[0041] According to one embodiment, a powertrain comprises an assembly as described above.

[0042] The output unit is driven solely by the electric motor. In other words, the powertrain does not include a heat engine or combustion engine.

[0043] According to another embodiment, an electric axle includes a powertrain as described above. BRIEF DESCRIPTION OF THE FIGURES

[0044] Other features and advantages of the invention will become apparent from the following description, with reference to the attached figures, which illustrate: [ Fig. 1 ] there figure 1 , a schematic diagram showing the context of use of the transmission assembly of the figure 3 . [ Fig. 2 ] there figure 2 , a schematic perspective view of a variant of the transmission assembly of the figure 1 [ Fig. 3 ] there figure 3 , a cross-sectional view of an embodiment of the invention. For clarity, identical or similar elements are identified by identical reference symbols across all figures. DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0045] In the description and 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 powertrain. By convention, the "radial" orientation is directed orthogonally to the axial orientation. The axial orientation relates, depending on the context, to one of the axes of rotation of the powertrain elements, for example, the rotor's axis of rotation. The "circumferential" orientation is directed orthogonally to the axial direction and orthogonally to the radial direction. The terms "external" and "internal" are used to define the relative position of one element with respect to another, with respect to the reference axis; an element close to the axis is thus described as internal, as opposed to an external element located radially at the periphery.

[0046] In practice, the various components of the powertrain have a torque input and a torque output. From a kinematic point of view, the input is located on the electric motor side, and the output is located on the wheel side of the vehicle.

[0047] On the figure 1 A powertrain group 1 is shown schematically.

[0048] This is a motor vehicle powertrain 1 comprising: an electric machine 2 comprising a rotor 21 rotating about an axis of rotation X, a first transmission assembly 3 comprising a first clutch 30 associated with a first transmission mechanism 40, a second transmission assembly 5 comprising a second clutch 50 associated with a second transmission mechanism 60, an output member 17 capable of being driven by the rotor 21 either through the first transmission mechanism or through the second transmission mechanism.

[0049] The powertrain 1 further includes a differential 8 capable of driving two laterally opposed wheels, or two sets of driven front and rear wheels of the vehicle.

[0050] A reduction stage 7, 9 is arranged between the output member 17 and the differential 8 so as to reduce the rotational speed between the output member 17 and the differential 8, and more globally between the electric machine 2 and the differential 8.

[0051] The first clutch 30 is capable, in a closed state, of transmitting torque respectively between the rotor 21 and the first transmission mechanism 40, but the transmission of torque between the rotor 21 and the first transmission mechanism 40 is interrupted when the first clutch 30 is opened.

[0052] The second clutch 50 is also capable, in a closed state, of transmitting torque respectively between the rotor 21 and the second transmission mechanism 60, but the transmission of torque between the rotor 21 and the second transmission mechanism 60 is interrupted when the second clutch 50 is open.

[0053] The first transmission mechanism 40 and the second transmission mechanism 60 have different gear ratios. Activating the first and / or second clutch allows the appropriate gear ratio to be selected. First gear, useful for starting and pulling away from the vehicle, is obtained using the second transmission mechanism 60, and second gear is obtained using the first transmission mechanism 40.

[0054] The first clutch 30 and the second clutch 50 are arranged axially on either side of the rotor 21. This allows the use of similar or even identical clutch structures, which standardizes the design elements of the first and second clutches and reduces the number of part numbers in the powertrain. Furthermore, it is possible to position the two clutches 30 and 50 close to their axis of rotation X.

[0055] Each clutch 30, 50 includes at least a first transmission interface 31, 51 and a second transmission interface 32, 52 cooperating with each other to transmit torque when the clutch 30, 50 is closed.

[0056] On the other hand, the transmission of torque between the first transmission interface 31, 51 and the second transmission interface 32, 52 of each clutch 30, 50 is interrupted when the clutch 30, 50 is opened.

[0057] The rotor 21, the first transmission interfaces 31, 51, and the second transmission interfaces 32, 52 are arranged such that there is an axis parallel to the X-axis that passes through both the rotor 21 and the first 31, 51 and second 32, 52 transmission interfaces. Thus, the rotor and the clutches can be placed approximately equidistant from the X-axis of rotation.

[0058] The rotor 21 has a radially external diameter greater than the radially external diameter of the first and second transmission interfaces 31, 32, 51, 52 of the first and second clutches 30, 50. The radial footprint of the electric machine and the two clutches is therefore compact.

[0059] The powertrain 1 comprises a housing 22 enclosing the electric machine 2, and the first and second clutches 30 and 50 are located outside the housing 22 of the electric machine 2. Kinematically, the clutches 30 and 50 are positioned as close as possible to the electric machine 2, upstream of the reduction gears. This means that the two clutches are located in a portion of the transmission chain where the torque is lowest. In the case of progressive friction clutches, in particular, this arrangement allows for greater clutch compactness. Preferably, the first clutch 30 is a progressive friction clutch, and the second clutch 50 is also a progressive friction clutch. This allows for smooth and gradual gear changes without abrupt acceleration. A progressive clutch is defined as a clutch whose transmissible torque can be controlled progressively.

[0060] The first clutch 30 and the second clutch 50 are wet multi-disc clutches.

[0061] The first clutch 30 and the second clutch 50 each have friction discs 31E, 31S, 51E, 52S. The first friction interfaces 31, 51 are formed by input friction discs 31E, 51E, and the second friction interfaces 32, 52 are formed by output friction discs 31S, 51S. The input and output friction discs of each clutch 30, 50 can be pressed axially against each other to transmit torque.

[0062] The first transmission assembly 3 comprises a first input shaft section 33 fixed in rotation to the rotor 21 and extending axially from the rotor 21 to the first clutch 30.

[0063] This first input shaft section 33 drives the first transmission interface 31 of the first clutch 30 into rotation.

[0064] In practice, the first input shaft section 33 is coupled in a rotationally fixed manner to a first input disc carrier 35 on which the input friction discs 31E of the first clutch 30 can be mounted, in an axially sliding manner and rotationally fixed around the X axis.

[0065] The second transmission assembly 5 includes a second input shaft section 53 fixed in rotation to the rotor 21 and extending axially from the rotor 21 to the second clutch 50.

[0066] This second input shaft section 53 drives the first transmission interface 51 of the second clutch 50 into rotation.

[0067] In practice, the second input shaft section 53 is rotationally coupled to a second input disc carrier 55 on which the input friction discs 51E of the second clutch 50 can be mounted axially sliding and rotationally fixed around the X axis.

[0068] Here, the first input shaft section 33 and the second input shaft section 53 are formed on a common input shaft 24 which is rotationally fixed to the rotor 21. The common input shaft 24 extends along the axis of rotation X, radially inside the rotor 21, extending axially beyond the rotor 21 on either side.

[0069] The output friction discs 32S of the first clutch 30 are mounted rotationally and axially slidingly to a first output disc carrier 37 of the first clutch 30.

[0070] Similarly, the output friction discs 52S of the second clutch 50 are also mounted rotationally and axially slidingly to a second output disc carrier 57 of the second clutch 50.

[0071] The first transmission mechanism 40 includes a first gear train and the second transmission mechanism 60 includes a second gear train.

[0072] The first gear train includes a first driving wheel 41 adapted to be driven in rotation by the second transmission interface 32 of the first clutch 30, when the first clutch 30 is closed. The first driving wheel 41 is mounted freely on the first input shaft section 33.

[0073] In practice the first output disc carrier 37 of the first clutch 30 can be directly fixed to the first driving wheel 41.

[0074] The second gear train includes a second driving wheel 61, which is driven in rotation by the second transmission interface 52 of the second clutch 50 when the second clutch 50 is closed. The second driving wheel 61 is mounted freely on the second input shaft section 53.

[0075] In practice the second output disc carrier 57 of the second clutch 50 can be directly fixed to the second drive wheel 61.

[0076] The first driving wheel 41 and the second driving wheel 61 are arranged axially on either side of the rotor 21.

[0077] The output member 17 is a shaft 17 arranged to be driven along an axis Y parallel to the axis of rotation X.

[0078] The first and second gear trains of the first and second transmission mechanisms 40, 60 are arranged in cascade, between the X axis and the Y axis.

[0079] The shaft 17 carries on the one hand a first driven wheel 42 of the first gear train 40 driven directly by the first driving wheel 41, and on the other hand a second driven wheel 62 of the second gear train 60 driven directly by the second driving wheel 61.

[0080] The driving wheel / driven wheel drive can also be done indirectly, that is to say via an intermediate toothed element.

[0081] The powertrain 1 also includes a disconnect device 6 associated here with the second transmission mechanism 60 so that the drive of the second transmission interface 52 of the second clutch 50 is interrupted when a torque is transmitted from the rotor 21 to the output member 17 via the first transmission mechanism 40.

[0082] In other words, the disconnecting device 6 is arranged to permit mutual rotational drive between the second transmission interface 52 of the second clutch 50 and the shaft 17, via the second transmission mechanism 60, when the second clutch 50 is closed, and to interrupt mutual rotational drive between the second transmission interface 52 of the second clutch 50 and the shaft 17, via the second transmission mechanism 60, when the second clutch 50 is open and the first clutch 30 is closed.

[0083] By avoiding unnecessary engagement of the second transmission mechanism 60, detrimental efficiency losses in the second transmission mechanism 60 are prevented, losses that could be linked in particular to the churning of the rotating transmission components. Unnecessary rotation of the output friction discs 52S of the second clutch 50 is also avoided.

[0084] The disconnecting device 6 is a device known to those skilled in the art, which may incorporate, for example, a dog clutch and / or a synchronizer. Its actuation may be hydraulic.

[0085] When first gear is engaged, the second clutch 50, normally open, is held closed by a closing command, while the first clutch 30, normally open, is held open and the disconnect device 6, normally open, is held closed. The shaft 17 is driven via the second transmission mechanism 60. The shaft 17 then transmits torque to the differential 8 via a third gear train 7, 9 which reduces the rotational speed.

[0086] When second gear is engaged, the first clutch 30, normally open, is held closed by a closing command, while the second clutch, normally open, is held open, and the disconnect device 6, normally open, is held open. Shaft 17 is driven via the first transmission mechanism 40. Shaft 17 further transmits torque to the differential 8 via a third gear train 7, 9.

[0087] The shift from first to second gear is achieved by de-energizing the closing command of the second clutch 50, applying a closing command to the first clutch 30, and interrupting the actuation of the disconnect device. The second clutch 50 and the disconnect device 6 then automatically return to their stable, open position, and the first clutch 30 moves into its closed position.

[0088] The assembly then consumes little energy, since the second output gear 62, mounted freely on the shaft 17, is not driven by the latter and does not unnecessarily drive the first driving gear 41 and the output friction discs 52S of the second clutch 50.

[0089] In one variant, the second clutch (50) is normally open and the first clutch is normally closed. The torque transmission system is then even better optimized in second gear, since none of the controls are powered in this most common operating mode.

[0090] In practice, a hydraulic interlock or via an electronic control can be provided between the second clutch 50 and the disconnecting device 6, to coordinate the openings and closings of the two components.

[0091] According to a variant, it is also possible to equip the first driven wheel 42 of the first transmission mechanism 40 with a disconnection device similar to the disconnection device 6.

[0092] Alternatively, at least some of the gear trains can be replaced by belt drives. For higher gear ratios, at least some of the gear trains can include an intermediate gear between the driving and driven gears.

[0093] The powertrain includes a first actuator 110 comprising a first chamber 112 intended to contain an actuation fluid and a first movable piston 111 capable of sliding axially in the first chamber 112. The first chamber 112 is formed in a housing of the powertrain 1.

[0094] The powertrain includes a second actuator 120 comprising a second chamber 122 intended to contain an actuation fluid and a second movable piston 121 capable of sliding axially in the second chamber 122. The second chamber 122 is also formed in the housing of the powertrain 1.

[0095] The actuation force of the first and second clutches 30 and 50 is directed axially towards the electric machine.

[0096] On the figure 2 A schematic representation of a variant of the powertrain of the figure 1 . In this variant, the driving wheels 41 and 61 have a smaller diameter respectively than the driven wheels 42 and 62 in order to reduce the rotational speed of the shaft 17 relative to the common input shaft 24.

[0097] On the figure 3 is represented as an embodiment of the invention.

[0098] The gear trains of the first transmission mechanism 40 and the second transmission mechanism 60 are arranged axially on the same side of the rotor 21. The first driving gear 41 is a first input pinion, and the second driving gear 61 is a second input pinion. The first input pinion 41 and the second input pinion 61 are arranged axially on the same side of the rotor. The first clutch 30 is positioned axially between the rotor 21 on one side and the first and second input pinions 41 and 61 on the other.

[0099] Thus the powertrain is more compact and it is possible to arrange the output shaft 17 axially on only one side of the rotor, which allows for more freedom in configuring the architecture of the powertrain 1.

[0100] The gear trains of the first transmission mechanism 40 and the second transmission mechanism 60 can be integrated within a modular reducer arranged axially on one side of the rotor 21, this module also being able to integrate the first clutch 30.

[0101] The electric machine 2 is housed in a casing 22. The electric machine 2 is arranged around an axis X and includes the rotor 21 and a stator 25. Here, "stator" means the component comprising the stator body 25a and the winding 25b.

[0102] Shaft 24 transmits torque to transmission assemblies 3 and 5. For this reason, it is called the common input shaft. The common input shaft 24 is driven in rotation by the rotor 21 around the X-axis. The rotor 21 and shaft 24 can, for example, be fixed to each other by press fitting.

[0103] The stator body 25a is tubular in shape and extends along the X-axis. The winding 25b extends axially along the stator body 25a. The winding 25b extends axially on each side of the stator body 25a, towards the clutches 30 and 50. The winding 25b includes winding heads that are formed in the portion of the winding 25b that extends axially from the stator body 25a.

[0104] The first input shaft section 33 and the second input shaft section 53 are arranged axially on either side of the rotor 21. On each side of the rotor 21, the housing 22 of the electric machine 2 comprises, respectively, a first projecting portion 221 towards the inside of the housing and a second projecting portion 222 towards the inside of the housing 22. The first projecting portion 221 comprises a first bore inside which is mounted a first roller bearing 11 guiding the first input shaft section 33 in rotation around the axis of rotation X. The second projecting portion 222 comprises a second bore inside which is mounted a second roller bearing 12 guiding the second input shaft section 53 in rotation around the axis of rotation X.

[0105] In addition, on each side of the rotor 21, the housing 22 of the electric machine 2 comprises respectively a first tubular portion 223 projecting outwards from the housing 22 and a second tubular portion 224 also projecting outwards from the housing 22.

[0106] The first input tree segment 33 and the second input tree segment 53 are formed in a common input tree 24 which is hollow.

[0107] The first input shaft section 33 is rotationally fixed to a first input disc carrier 35 of the first clutch 30. The input friction discs 31E of the first clutch are mounted on the first input disc carrier 35, rotationally fixed about the X-axis and axially movable. The input friction discs form the first transmission interface 31 of the first clutch 30.

[0108] A first output disc carrier 37 is mounted rotationally fixed to the first input pinion 41 of the first transmission mechanism 40. Here, a toothed wheel 91 of a locking device, also called a "park lock," is welded to the first output disc carrier 37 and rigidly coupled rotationally to the first input pinion 41. In other words, the first input pinion 41 is mounted rotationally fixed to the first output disc carrier 37 via the toothed wheel 91 of the locking device. The toothed wheel 91 of the locking device is thus advantageously associated with the gear train associated with the second gear ratio.

[0109] The powertrain 1 includes a first actuator 110 having a first moving element 111 capable of closing the first clutch 30 to transmit torque between the first transmission interface 31 and the second transmission interface 32 of the first clutch 30, i.e. between the input friction discs 31e and the output friction discs 32s of the first clutch 30. The first actuator 110 is arranged axially between the rotor 21 and the first clutch 30.

[0110] The first moving element 111 of the first actuator 110 transmits to the friction discs 31e, 32s of the first clutch 30 an axial translational movement so that the friction discs 31e, 32s of the first clutch are pressed axially against each other against a first reaction element 113 of the first clutch 30. The first reaction element 113 is formed here on a cup 114 arranged so as to transmit a torque between the first output disc carrier 37 and the toothed wheel 91 of the locking device.

[0111] A first kinematic link 116 rotating around the axis of rotation X and a first pusher 115 are interposed between the first moving element 111 of the first actuator 110 and the friction discs 31e, 32s of the first clutch 30 to transfer the axial forces of the first moving element 111 to the friction discs 31e, 32s of the first clutch 30. The friction discs 31e, 32s of the first clutch 30 are then axially pressed against each other between on the one hand the first pusher 115 and on the other hand the cup 114.

[0112] The first rotary kinematic link 116 is interposed between the first moving element 111 and the first pusher 115 so that the first moving element 111 is fixed in rotation relative to the casing 22 of the electrical machine 2 and the first pusher 115 is able to rotate with the friction discs 31e, 32s of the first clutch 30 when the first clutch 30 is closed.

[0113] The first actuator 110 includes a first chamber 112 intended to contain an actuation fluid and the first moving element 111 is formed by a first moving piston 111 capable of sliding axially in the first chamber 112.

[0114] A first group of springs 117 is arranged axially between the first output disc carrier 37 of the first clutch 30 and the first pusher 115 so as to allow the first pusher 115 to return to a rest position when the fluid pressure in the first chamber 112 is below a first predetermined threshold.

[0115] A bearing 119 is mounted on the first tubular portion 223 and a first load-bearing element 118 is arranged in axial support against this bearing 119 so as to absorb at least part of the forces transmitted from the first pusher 115 to the friction discs 31e, 32s of the first clutch 30. The first group of springs 117 also bears against the first load-bearing element 118 on the side of the first load-bearing element 118 facing the electric machine 2, while on its side opposite the electric machine 2, the first load-bearing element 118 is in axial support directly or indirectly against the bearing 119.

[0116] The first force recovery element 118 is formed here on the radially internal portion of the first output disc carrier 37.

[0117] On the other side of the electric machine 2, the second input shaft section 53 is fixed for rotation to a second input disc carrier 55 of the second clutch 50. The input friction discs 51E of the second clutch 50 are mounted on the second input disc carrier 50 for rotation about the X-axis and are axially movable. The input friction discs 51E form the first transmission interface 51 of the second clutch 50.

[0118] A second output disc carrier 57 is mounted to rotate securely with the second input pinion 61 of the second transmission mechanism 60.

[0119] The second transmission mechanism 60 includes a connecting shaft 26 that extends axially. This connecting shaft is arranged radially inside the rotor 21 and radially inside the common input shaft 24 such that a first portion of the connecting shaft 26 is located inside the first input shaft section 33 and a second portion of the connecting shaft 26 is located inside the second input shaft section 53. Rotational guiding elements and / or bearings such as needle bearings may be inserted between the common input shaft 24 and the connecting shaft 26 to facilitate the rotational guidance of the two shafts.

[0120] The connecting shaft 26 is thus configured to transmit torque between the second transmission interface 52 of the second clutch 50 and the second input pinion 61 of the second transmission mechanism 60.

[0121] In other words, the second input pinion 61 is mounted rotationally fixed to the second output disc carrier 57 via the connecting shaft 26.

[0122] The powertrain 1 includes a second actuator 120 having a second moving element 121 suitable for closing the second clutch 50 to transmit torque between the first transmission interface 51 and the second transmission interface 52 of the second clutch 50, i.e. between the input friction discs 51e and the output friction discs 52s of the second clutch 50. The second actuator 120 is arranged axially between the rotor 21 and the second clutch 50.

[0123] The second moving element 121 of the second actuator 120 transmits an axial translational movement to the friction discs 51e, 52s of the second clutch 50 so that the friction discs 51e, 52s of the second clutch are pressed axially against each other against a second reaction element 123 of the second clutch 50. The second reaction element 123 is formed here on a flange 124 arranged to transmit a torque between the second output disc carrier 57 and the connecting shaft 26.

[0124] A second kinematic link 126 rotating around the axis of rotation X and a second pusher 125 are interposed between the second moving element 121 of the second actuator 120 and the friction discs 51e, 52s of the second clutch 50 to transfer the axial forces of the second moving element 121 to the friction discs 51e, 52s of the second clutch 50. The friction discs 51e, 52s of the second clutch 50 are then axially pressed against each other between on the one hand the second pusher 125 and on the other hand the flange 124.

[0125] The second rotary kinematic link 26 is interposed between the second moving element 121 and the second pusher 125 so that the second moving element 121 is fixed in rotation relative to the casing 22 of the electric machine and the second pusher 125 is able to rotate with the friction discs 51e, 52s of the second clutch 50 when the second clutch 50 is closed.

[0126] The second actuator 120 includes a second chamber 122 intended to contain an actuation fluid and the second moving element 121 is formed by a second moving piston 121 capable of sliding axially in the second chamber 122.

[0127] A spring washer 127 is arranged axially between the second output disc carrier 57 of the second clutch 50 and the second pushrod 125 so as to allow the second pushrod 125 to return to its rest position when the fluid pressure in the second chamber 122 is below a second predetermined threshold. Alternatively, a second set of axially extending helical springs can be provided around the axis of rotation X to replace this spring washer.

[0128] A bearing 129 is mounted on the second tubular section 224 and a second load-bearing element 128 is arranged in axial support against this bearing 129 so as to absorb at least part of the forces transmitted from the second pusher 125 to the friction discs 51e, 52s of the second clutch 50. The spring washer 127 also bears against the second load-bearing element 128 on the side of the second reaction element facing the electric machine 2, while on its side opposite the electric machine 2, the second load-bearing element 128 is in axial support against the bearing 129.

[0129] The second force recovery element 128 is formed here on the radially internal portion of the second output disc carrier 57.

[0130] To reduce the manufacturing cost of such a powertrain, the first and second clutches 30, 50 can incorporate similar components, meaning they are standardized for both clutches 30 and 50. For example, the first moving piston 111 and the second moving piston 121 are identical. Similarly, the input friction discs 31E of the first clutch 30 are identical to the input discs 51E of the second clutch 50. The output friction discs 32s of the first clutch 30 are also identical to the output discs 52s of the second clutch 50. The pushrods 115 and 125, and the input disc holders 35, 55 and output disc holders 37, 57 can also be identical.

[0131] The actuation forces of the first 30 and second 50 clutches are directed axially in the opposite direction to the electric machine 2.

[0132] The first tubular section 223 extends along the axis of rotation X and projects axially from one side of the electrical machine 2. The first clutch 33 is arranged partly around the first tubular section 223. In particular, most of the friction discs 31E, 32S of the first clutch 30 are arranged around the first tubular section 223. The first input disc carrier 35 and the first output disc carrier 37 are also arranged partly around the first tubular section 223 of the housing 22.

[0133] The first tubular portion 223 includes several distribution conduits 252 for cooling fluid extending axially and opening radially inside the friction discs 31E, 32s, and axially into an axial sector occupied by the friction discs.

[0134] The casing 22 of the electric machine 2 includes a first side wall 225, arranged on a first side of the electric machine 2. The first side wall 225 is arranged axially between the rotor 21 and the first clutch 30. The first tubular portion 223 extends axially from this first side wall 225.

[0135] The first side wall 225 includes several fluid supply conduits 251. These supply conduits 251 extend radially and communicate with the cooling fluid distribution conduits 252 of the first tubular portion 223. The first side wall 225 extends generally radially outwards from the first tubular portion 223.

[0136] The fluid supply conduits 251, the first chamber 112 and / or the second chamber 122 can be arranged at least partly radially inside the winding heads, with overlap.

[0137] The first chamber 112 is formed in the casing 22 of the electric machine 2, more precisely in the first side wall 225. The first side wall 225 includes a radially internal base 226 from which the first tubular portion 223 extends axially, on the side of the first clutch 30. The first projecting portion 221, having the mounting bore of the first bearing 11, extends on the other side of the radially internal base 226 of the first wall 225.

[0138] The first chamber 112 is formed in the radially internal base 226 of the first wall 225. The radially internal base 226 of the first wall 226 has a greater thickness compared to the rest of the first wall 225. The first chamber 112 is arranged radially outside the distribution conduits 252. The first chamber 112 also communicates with the fluid supply conduits 251.

[0139] The cooling fluid distribution channels 252 also open radially into the first projecting portion 221 inside the mounting bore of the first bearing 11. The distribution channels 252 of the first tubular portion 223 open axially with respect to the first bearing 11 so as to allow lubrication of the latter.

[0140] The second tubular section 224 extends along the axis of rotation X and projects axially from a second side opposite the first side of the electric machine 2. The second clutch 50 is arranged partly around the second tubular section 224. In particular, most of the friction discs 51E, 52S of the second clutch 50 are arranged around the first tubular section 224. The second input disc carrier 55 and the second output disc carrier 57 are also arranged partly around the second tubular section 224 of the housing 22.

[0141] The second tubular portion 224 includes several distribution conduits 252 for cooling fluid extending axially and opening radially inside the friction discs 51E, 52s, and axially into an axial sector occupied by the friction discs 51E, 52s.

[0142] Oil can circulate in the network formed by the supply pipes 251 and distribution pipes 252.

[0143] The casing 22 of the electric machine 2 includes a second side wall 227, arranged on a second side of the electric machine 2. The second side wall 227 is arranged axially between the rotor 21 and the second clutch 50. The second tubular portion 224 extends axially from this second side wall 227.

[0144] The second side wall 227 includes several fluid supply conduits 251. These supply conduits 251 extend radially and communicate with the cooling fluid distribution conduits 252 of the second tubular section 224. The second side wall 227 extends generally radially outwards from the second tubular section 224.

[0145] The second chamber 122 is also formed in the housing 22 of the electric machine 2, more precisely in the second side wall 227. The second side wall 227 includes a radially internal base 228 from which the second tubular portion 224 extends axially, on the side of the second clutch 50. The second projecting portion 222, having the mounting bore for the second bearing 12, extends on the other side of the radially internal base 228 of the second side wall 227.

[0146] The second chamber 122 is formed in the radially internal base 228 of the second wall 227. The radially internal base 228 of the second wall 227 is therefore thicker than the rest of the second wall 227. The second chamber 122 is arranged radially outside the distribution conduits 252 of the second tubular section 224. The second chamber 122 also communicates with the fluid supply conduits 251 of the second lateral wall 227.

[0147] The cooling fluid distribution channels 252 of the second tubular portion 224 also open radially into the second projecting portion 222 inside the mounting bore of the second bearing 12. The distribution channels 252 of the second tubular portion 224 open axially with respect to the second bearing 12 so as to allow lubrication of the latter.

[0148] Needles are interposed between the common input shaft 24 of the two clutches 30, 50 and the connecting shaft 26. The common input shaft 24 has several lubrication channels 241 opening radially inwards and outwards. These lubrication channels 241 communicate with one of the supply channels 251 of the first side wall 225 and the second side wall 227. Thus, the needles interposed between the shafts can be lubricated.

[0149] The housing 22 of the electric machine 2 comprises a casing 28. The first side wall 225 is formed on a cover 229 attached to this casing 28. The casing 28 comprises a cylindrical portion in which the electric machine 2 is housed. The cover 229 is sealed onto this cylindrical portion. The first tubular portion 223 and the first side wall 225 are formed as a single piece within the cover 229.

[0150] The second side wall 227 is formed in one piece with the cylindrical portion of the housing and forms a bottom of the housing 28. Similarly, the second tubular portion 224 and the second side wall 227 are formed in one piece in the housing 28.

[0151] The gear trains of the transmission mechanisms 40, 60 which are not fully represented on the figure 2 may have the same characteristics as those of the figure 1 They can cause a vehicle differential as explained in the solution to the figure 1 .

Claims

1. A transmission assembly comprising: - an electric machine (2) equipped with a rotor (21) adapted to rotate about an axis of rotation (X), - a casing (22) for the electric machine, enclosing the electric machine (2), - a first clutch (30) intended to drive a first transmission mechanism (40) in rotation, wherein the casing (22) of the electric machine (2) comprises a first tubular portion (223) extending along the axis of rotation (X) and around the axis of rotation (X), the first tubular portion (223) of the casing (22) projecting axially outward from the casing on a first side of the electric machine, the first clutch (30) being disposed at least partially around the first tubular portion (223), characterized in that the first clutch (30) comprises a plurality of friction discs (31E, 32s), at least a portion of the friction discs (31E, 32s) being disposed around the first tubular portion (223).

2. The transmission assembly according to the preceding claim, wherein the first clutch (30) is a wet clutch and the first tubular portion (223) comprises at least one distribution duct (252) for cooling fluid, said at least one distribution duct (252) extending axially and opening radially into the interior of the friction discs (31E, 32s) of the first clutch.

3. The transmission assembly according to the preceding claim, wherein said at least one distribution duct (252) opens axially into an axial sector occupied by the friction discs (31E, 32s) of the first clutch (30).

4. The transmission assembly according to any one of the preceding claims, wherein the transmission assembly comprises a second clutch (50) intended to drive a second transmission mechanism (60) in rotation, and the casing (22) of the electric machine (2) comprises a second tubular portion (224) extending along the axis of rotation (X), the second tubular portion (224) projecting axially outward from the casing (22) on a second side of the electric machine (2) axially opposite the first side, the second clutch (50) being disposed at least partially around the second tubular portion (224).

5. The transmission assembly according to the preceding claim, wherein the second clutch (50) comprises a plurality of friction discs (51E, 52s), at least a portion of the friction discs being disposed around the second tubular portion (224); the second clutch (50) being a wet clutch and the second tubular portion comprising at least one cooling fluid distribution duct, said at least one distribution duct (252) extending axially and opening radially into the interior of the friction discs (51E, 52s) of the second clutch (50), and said at least one distribution duct (252) opening axially into an axial sector occupied by the friction discs (51E, 52s) of the second clutch (50).

6. The transmission assembly according to the preceding claim, wherein the rotor (21) is mounted so as to be integral in rotation with a common input shaft (24), common to the first and second clutches (30, 50), a first rolling bearing (11) being radially interposed between the casing (22) of the electric machine and the common input shaft (24), the first rolling bearing (11) being located with respect to the rotor (21) on the side of the first clutch (30), and a second rolling bearing being radially interposed between the casing (22) of the electric machine and the common input shaft (24), the second rolling bearing (12) being located with respect to the rotor (21) on the side of the second clutch (50), the distribution duct (252) of the first tubular portion (223) opening axially opposite the first rolling bearing (11) and / or the distribution duct of the second tubular portion (224) opening axially opposite the second rolling bearing (12).

7. The transmission assembly according to any one of the preceding claims, wherein the casing (22) of the electric machine (2) comprises a first side wall (225) disposed axially between the rotor (21) and the first clutch (30) and the casing (22) of the electric machine (2) comprises a second side wall (227) disposed axially between the rotor (21) and the second clutch (50); and wherein the first side wall (225) comprises at least one fluid supply duct (251) that extends radially and communicates with said at least one cooling fluid distribution duct (252) of the first tubular portion (223) and / or the second side wall (227) comprises at least one fluid supply duct (251) that extends radially and communicates with said at least one cooling fluid distribution duct (252) of the second tubular portion (224).

8. The transmission assembly according to the preceding claim, wherein the first clutch (30) is actuated by a first actuator (110) which comprises a first chamber (112) intended to contain an actuating fluid and a first movable piston (111) adapted to slide axially in the first chamber (112), the first chamber (112) being formed in the casing (22) of the electric machine (2), and said at least one fluid supply duct (251) of the first side wall (225) communicating with the first chamber; and / or the second clutch (50) is actuated by a second actuator (120) which comprises a second chamber (122) intended to contain an actuating fluid and a second movable piston (121) adapted to slide axially in the second chamber (122), the second chamber (122) being formed in the casing (22) of the electric machine (2), and said at least one fluid supply duct (251) of the second side wall (227) communicating with the second chamber (122).

9. The transmission assembly according to claims 5 and 7, wherein the common input shaft (24) is hollow and the second transmission mechanism (60) comprises a connecting shaft (26) extending axially inside the common input shaft (24), rolling elements, such as needles, being interposed between the common input shaft (24) and the connecting shaft (26), the common input shaft (24) comprising at least one lubrication duct (241) communicating with said at least one supply duct (251) of the first side wall (225) and / or of the second side wall (227), said at least one lubrication duct (241) opening out so as to lubricate the rolling elements.

10. The transmission assembly according to any one of the preceding claims, wherein the first transmission mechanism (40) comprises a first reduction device and the second transmission mechanism (60) comprises a second reduction device connected to the second clutch (50) by the connecting shaft (26), the first and second reduction devices being located axially on the same side of the electric machine (2).

11. The transmission assembly according to claim 7 or 8, wherein the casing (22) of the electric machine (2) comprises a housing (28) and one of the first and second side walls (225, 227) is formed on a cover (229) attached to the housing (28).

12. The transmission assembly according to claim 7 or 8 or 11, wherein the first tubular portion (223) and the first side wall (225) are formed in one piece, in particular in the cover (229).