HYBRID VEHICLE DRIVE SUBASSEMBLY, HYBRID ENGINE ASSEMBLY AND HYBRID DRIVE METHOD

Abstract

A hybrid drive subassembly (10) of a vehicle comprises at least one primary shaft (12), at least one secondary shaft (16), a transmission (18) comprising at least one intermediate shaft (26) separate from the primary shaft (12) and the secondary shaft (16), and an electric motor unit comprising at least one reversible electric machine (56), and a coupling device (58) capable of assuming at least one intermediate coupling position in which an output shaft (57) of the reversible electric machine (56) is kinematically linked to the intermediate shaft (26), and one secondary coupling position in which the output shaft (57) of the reversible electric machine (56) is kinematically linked to the secondary shaft (16) without passing through the intermediate shaft (26). (Shortcut figure: Figure 1)

Description

Title of the invention: HYBRID VEHICLE DRIVE SUB-ASSEMBLY, HYBRID ENGINE UNIT AND HYBRID DRIVE METHOD Technical field of the invention

[0001] The invention relates to a drive subassembly intended to be positioned between an engine, for example an internal combustion engine, and one or more drive wheels of a vehicle. It relates in particular, though not exclusively, to such a subassembly intended to equip a heavy goods vehicle, that is to say, a road vehicle weighing more than 3.5 tonnes, in particular a tractor unit or a rigid truck, prior art

[0002] Document AT520019B1 describes a powertrain assembly of a vehicle, comprising a primary shaft intended to be driven by an engine of the vehicle, a secondary shaft intended to drive a set of one or more drive wheels of the vehicle, and a transmission comprising one or more primary gears fixed in rotation to the primary shaft or capable of being coupled to the primary shaft, a plurality of secondary gears fixed in rotation to the secondary shaft or capable of being coupled to the secondary shaft, and an intermediate shaft to which intermediate gears are fixed in rotation, the primary gear(s) and the secondary gears each meshing with a corresponding gear among the intermediate gears.The powertrain assembly also includes a reversible electric machine kinematically linked to the intermediate shaft and capable of operating as a current generator to brake the intermediate shaft or as a drive motor for the intermediate shaft. Such an electric machine allows for different operating modes, including transient operation of the electric machine to brake or accelerate the intermediate shaft and facilitate synchronization of the transmission during gear changes, motor operation to assist the drive of the vehicle's main engine outside of gear changes, and operation as an electric generator to supply power to vehicle accessories or a battery, particularly during vehicle braking.

[0003] Document GB1435517A describes a transmission box comprising a an output shaft and a return shaft, as well as a gear train between the return shaft and the output shaft, comprising a first gear fixed to one of the two shafts and a second gear capable of being fixed to the other shaft by via a dog clutch. A reversible electric machine is permanently coupled to the return shaft, and the coupling means are controlled to synchronize the speed of the second gear and the dog clutch before they engage.

[0004] In these devices, the intermediate shaft or the return shaft is always connected to the shaft of the electric machine, which limits the possible operating modes. Description of the invention

[0005] The invention aims to remedy the drawbacks of the prior art and to propose a better integration of an electric machine to an intermediate shaft of a transmission box, making it possible to consider modes of operation previously inaccessible.

[0006] To this end, according to a first aspect of the invention, a hybrid vehicle drive subassembly is proposed, of the type comprising: at least one primary shaft, at least one secondary shaft, and a transmission comprising at least one intermediate shaft separate from the primary and secondary shafts, and gear trains for achieving several transmission ratios between the primary and secondary shafts via the intermediate shaft. The hybrid subassembly also comprises an electric motor unit comprising at least one reversible electric machine, and a coupling device which, in at least one intermediate coupling position, kinematically links an output shaft of the reversible electric machine to the intermediate shaft.Remarkably, the coupling device, in at least one secondary coupling position, kinematically links the output shaft of the reversible electric machine to the secondary shaft without passing through the intermediate shaft.

[0007] In the secondary coupling position, the coupling device allows for direct power transmission between the reversible electric machine and the secondary shaft without driving the intermediate shaft. This allows for various operating modes, which will be described later, including: a mode of permanent electrical drive of the secondary shaft by the reversible electric machine operating as a motor, a transient mode of maintaining traction during gear changes, and a purely regenerative braking mode minimizing the resisting mechanical torque. These operating modes are in addition to those available in the intermediate coupling position.

[0008] The reversible electric machine may in particular be a permanent magnet synchronous machine, an asynchronous machine, a variable reluctance electric machine or a variable reluctance synchronous electric machine, known as a synchro-reluctant machine.

[0009] According to one embodiment, the coupling device, in at least one uncoupled position, simultaneously kinematically uncouples the output shaft of the reversible electric machine from the intermediate shaft and the secondary shaft. This position of the coupling device allows for additional operating modes in which the electric machine is uncoupled, either because it is not required for the operation of the gearbox, or because it is used for other purposes, for example, to drive another rotating component. Decoupling the electric machine reduces inertia and resistive torque at the intermediate shaft and relieves stress on the rotor guide bearings, thereby increasing their service life.

[0010] According to one embodiment, the coupling device comprises at least one coupling mechanism permanently kinematically linked to the output shaft of the reversible electric machine, an intermediate speed reducer permanently kinematically linked to the intermediate shaft, and a secondary speed reducer permanently kinematically linked to the secondary shaft. The secondary speed reducer may advantageously comprise a reversing gear guided in rotation by a guide bearing coaxial with the intermediate shaft.

[0011] The reversible electric machine should preferably be dimensioned so as to be fully operational for wide operating ranges in the various operating modes envisaged. Thus, it is preferable that the reversible electric machine meet one or more of the following criteria: • the reversible electric machine is capable of continuously developing a motor torque greater than 300 Nm, and preferably greater than 350 Nm, in a speed range of more than 1000 rpm, and preferably more than 2000 rpm, including a lower limit which is less than 6000 rpm, and preferably less than 5000 rpm, and an upper limit which is greater than 6000 rpm, preferably greater than 7000 rpm, and preferably greater than 9000 rpm; • the reversible electric machine is capable of developing a resisting torque greater than 400 Nm and preferably greater than 450 Nm in a speed range of more than 3000 rpm, and preferably more than 4000 rpm having a lower limit which is less than 6500 rpm, and preferably less than 6000 rpm and an upper limit which is greater than 9000 rpm, and preferably greater than 10000 rpm, for 30 seconds; • The reversible electric machine is capable of developing a motor torque greater than 50 Nm and preferably greater than 60 Nm in a speed range of more than 5500 rpm, and preferably more than 7000 rpm, having a lower limit which is less than 5000 rpm, and preferably less than 4500 rpm and an upper limit which is greater than 10000 rpm, and preferably greater than 11000 rpm, for 5 seconds in transient gear change regime.

[0012] In practice, the coupling device in the intermediate coupling position kinematically links the output shaft of the reversible electric machine to the intermediate shaft with a so-called intermediate transmission ratio, while the coupling device in the secondary coupling position kinematically links the reversible electric machine to the secondary shaft with a so-called secondary transmission ratio. According to various embodiments, the coupling device meets one or more of the following criteria: • the secondary transmission ratio is greater than 6, and preferably greater than or equal to 8; • the intermediate transmission ratio greater than 4, and preferably greater than or equal to 6 between the intermediate shaft and the output shaft of the reversible electric machine; • the secondary transmission ratio is strictly greater than the intermediate transmission ratio, preferably with a factor greater than or equal to 1.5 between secondary transmission ratio and intermediate transmission ratio.

[0013] It may be advantageous to have several transmission ratios between the reversible electric machine and the intermediate shaft and / or between the reversible electric machine and the secondary shaft. To this end, one or more of the following arrangements may be made: • the coupling device, in an additional intermediate coupling position, kinematically links the reversible electric machine to the intermediate shaft with an additional intermediate transmission ratio distinct from the intermediate transmission ratio; • the coupling device, in an additional secondary coupling position, kinematically links the reversible electric machine to the secondary shaft with an additional secondary transmission ratio distinct from the secondary transmission ratio.

[0014] According to a particularly advantageous embodiment, the hybrid sub-assembly further comprises a power take-off element, capable of being driven at least by the reversible electric machine, preferably in one of the following ways: • the power take-off element is kinematically linked permanently to the intermediate shaft; • The power take-off unit is kinematically linked to the intermediate shaft by the intermediary of the coupling device in the intermediate coupling position; • the power take-off unit is kinematically linked to the output shaft of the reversible electric machine via the coupling device in the intermediate coupling position; • The power take-off unit is permanently kinematically linked to the output shaft of the reversible electric machine.

[0015] It is then possible to consider driving the power take-off by the reversible electric machine without using the vehicle's main engine, which makes it possible to reach rotational speeds much higher than 1000 rpm, for example higher than 1500 rpm, and where appropriate up to 5000 rpm.

[0016] In practice, the transmission may advantageously include: • one, or preferably several, primary gears suitable for coupling to the primary shaft, for example by one or more coupling and uncoupling mechanisms, for example synchronizers and / or dog clutches, • several secondary gears capable of being coupled to the secondary shaft, for example by one or more coupling and uncoupling mechanisms, for example synchronizers and / or dog clutches, • intermediate gears permanently fixed to the intermediate shaft, the primary gear(s) and secondary gears each permanently meshing with a corresponding gear among the intermediate gears to create gear trains.

[0017] In practice, the transmission includes coupling mechanisms for alternately coupling each of the primary gears to the primary shaft, and each of the secondary gears to the secondary shaft. If necessary, the hybrid sub-assembly may further include a dry or wet friction clutch for placement between the primary shaft and the main motor.

[0018] Various configurations of the primary gears, secondary gears, intermediate shaft and rotor of the reversible electric machine are conceivable.

[0019] According to one embodiment, the primary tree and the secondary tree have coincident axes of revolution. Alternatively, these axes are parallel and distant.

[0020] According to an example embodiment, the output shaft of the reversible electric machine has an axis of revolution parallel to an axis of revolution of the intermediate shaft, one or more of the following characteristics preferably being realized: • the axis of revolution of the output shaft coincides with the axis of revolution of the intermediate tree; • the axis of revolution of the output shaft is distant from the axis of revolution of the intermediate shaft; • the axis of revolution of the output tree is distant from one axis of revolution of the primary tree; • the axis of revolution of the output tree is distant from one axis of revolution of the secondary tree.

[0021] According to one embodiment, the coupling device comprises an epicyclic gear train arranged kinematically between the output shaft and the secondary shaft.

[0022] Depending on different variants, the coupling device comprises one or more of the following coupling mechanisms: • a dog clutch mechanism, • a synchronizer mechanism, • a clutch mechanism, preferably a friction clutch mechanism, preferably wet, • a dual friction clutch, preferably wet, • a triple friction clutch, preferably wet.

[0023] In particular, a non-synchronizing dog clutch mechanism may be considered in cases where the electric machine itself is intended to be used to synchronize the coupling device with the associated gear.

[0024] According to one embodiment, the hybrid subassembly is equipped with a control unit for the reversible electric machine and the coupling device, and sensors capable of generating a signal representing the rotational speed of the intermediate shaft or a kinematically linked component thereof, and a signal representing the rotational speed of the reversible electric machine or a kinematically linked component thereof. The control unit can, in particular, be used to synchronize the coupling device.Preferably, the control unit is capable, in a disengaged state of the coupling device, of controlling the reversible electric machine so that a relative rotational speed between the coupling member kinematically linked to the reversible electric machine and the coupling member kinematically linked to the intermediate shaft is achieved under a predetermined condition, and, when the predetermined condition is met, of controlling a coupling of the coupling device. The predetermined condition could, for example, be a zero relative rotational speed or a predetermined relative sliding speed.

[0025] According to another aspect of the invention, it comprises a hybrid power unit with a main engine, preferably an internal combustion engine, and a hybrid sub-assembly as described above. The main engine is equipped with a drive shaft main linked to the primary shaft directly or via a clutch or torque converter.

[0026] Preferably, the coupling device control unit is operational for controlling one or more of the following operating modes: • a transient mode of maintaining traction during a gear change, in which the coupling device is positioned in the secondary coupling position, the main motor is disengaged from the intermediate shaft, and the reversible electric machine is controlled to generate motor torque on the secondary shaft or to minimize a speed variation of the secondary shaft while a gear change of the transmission is being controlled; • a pure regenerative slowing mode without the intermediate shaft, in which the coupling device is positioned in the secondary coupling position, the secondary shaft is uncoupled from the intermediate shaft and electrical energy is generated with the reversible electric machine operating as a generator; • a direct electric drive mode without the intermediate shaft, in which the coupling device is positioned in the secondary coupling position, the intermediate shaft is uncoupled from the secondary shaft, and the reversible electric machine is the driving machine.

[0027] Preferably, the control unit is operational for controlling one or more of the following operating modes: • a reinforcement mode, in which the gearbox performs one of the transmission ratios between the primary shaft and the secondary shaft via the intermediate shaft, the main motor is supplied so as to drive the primary shaft and exert a main motor torque on the intermediate shaft, the coupling device is positioned in the intermediate coupling position, and the reversible electric machine generates a reinforcement motor torque on the intermediate shaft, of the same sign as the main motor torque; • a charging mode, in which the transmission is positioned so as to connect the primary shaft to the intermediate shaft, the main motor is supplied so as to drive the primary shaft and exert a main motor torque on the intermediate shaft, the coupling device is positioned in the intermediate coupling position, and kinetic energy is converted into electrical energy with the reversible electric machine operating as a generator; • a transient mode of synchronization of the intermediate tree during a passing one of the transmission ratios of the transmission box, in which the coupling device is positioned in the intermediate coupling position, the main motor is uncoupled from the intermediate shaft, then the reversible electric machine is controlled so as to bring the intermediate shaft to a set speed allowing the engagement of the secondary gear before recoupling the main motor to the intermediate shaft; • an indirect electric drive mode, in which the coupling device is positioned in the intermediate coupling position and the main motor is uncoupled from the intermediate shaft while the intermediate shaft is kinematically linked to the secondary shaft, then the reversible electric machine is controlled according to a vehicle speed setpoint; • a regenerative braking mode via the intermediate shaft, in which the coupling device is positioned in the intermediate coupling position, the main drive shaft is decoupled from the intermediate shaft and the reversible electric machine is driven to operate as a generator; • a hybrid motor braking mode, in which the coupling device is positioned in the intermediate coupling position, one of the transmission ratios between the primary shaft and the secondary shaft passing through the intermediate shaft being engaged, the primary shaft being kinematically linked to the main motor shaft, and kinetic energy is converted into electrical energy with the reversible electric machine operating as a generator and kinetic energy is converted into heat with the main motor developing a resisting torque; • a power take-off drive mode, in which the coupling device is positioned in the intermediate coupling position and the main engine is uncoupled from the intermediate shaft, the intermediate shaft from the secondary shaft, and then the reversible electric machine is controlled to drive a power take-off coupled to the intermediate shaft.

[0028] According to another aspect of the invention, it relates to a hybrid drive method for a vehicle comprising a hybrid powertrain according to claim as described above. With a coupling device control unit, one or more of the following operating modes are controlled: • a transient traction maintenance mode during a gear change, in which the coupling device is positioned in the secondary coupling position, the main motor is disengaged from the intermediate shaft, and the reversible electric machine is controlled so as to to generate engine torque on the secondary shaft or to minimize a speed variation of the secondary shaft while commanding a gear change of the transmission; • a pure regenerative slowing mode without the intermediate shaft, in which the coupling device is positioned in the secondary coupling position, the secondary shaft is uncoupled from the intermediate shaft and electrical energy is generated with the reversible electric machine operating as a generator; • a direct electric drive mode without the intermediate shaft, in which the coupling device is positioned in the secondary coupling position, the intermediate shaft is uncoupled from the secondary shaft, and the reversible electric machine is the driving machine.

[0029] Preferably, one or more of the following operating modes are controlled with the control unit: • a reinforcement mode, in which the gearbox performs one of the transmission ratios between the primary shaft and the secondary shaft via the intermediate shaft, the main motor is supplied so as to drive the primary shaft and exert a main motor torque on the intermediate shaft, the coupling device is positioned in the intermediate coupling position, and the reversible electric machine generates a reinforcement motor torque on the intermediate shaft, of the same sign as the main motor torque; • a charging mode, in which the transmission is positioned so as to connect the primary shaft to the intermediate shaft, the main motor is supplied so as to drive the primary shaft and exert a main motor torque on the intermediate shaft, the coupling device is positioned in the intermediate coupling position, and kinetic energy is converted into electrical energy with the reversible electric machine operating as a generator; • a transient mode of synchronizing the intermediate shaft during a shift of one of the transmission ratios of the gearbox, in which the coupling device is positioned in the intermediate coupling position, the main motor is disengaged from the intermediate shaft, then the reversible electric machine is controlled so as to bring the intermediate shaft to a set speed allowing the engagement of the secondary gear before recoupling the main motor to the intermediate shaft; • an indirect electric drive mode, in which the coupling device in the intermediate coupling position and the main motor is uncoupled from the intermediate shaft while the intermediate shaft is kinematically linked to the secondary shaft, then the reversible electric machine is controlled according to a vehicle speed setpoint; • a regenerative braking mode via the intermediate shaft, in which the coupling device is positioned in the intermediate coupling position, the main drive shaft is decoupled from the intermediate shaft and the reversible electric machine is driven to operate as a generator; • a hybrid motor braking mode, in which the coupling device is positioned in the intermediate coupling position, one of the transmission ratios between the primary shaft and the secondary shaft passing through the intermediate shaft being engaged, the primary shaft being kinematically linked to the main motor shaft, and kinetic energy is converted into electrical energy with the reversible electric machine operating as a generator and kinetic energy is converted into heat with the main motor developing a resisting torque; • a power take-off drive mode, in which the coupling device is positioned in the intermediate coupling position and the main engine is uncoupled from the intermediate shaft, the intermediate shaft from the secondary shaft, and then the reversible electric machine is controlled to drive a power take-off coupled to the intermediate shaft. brief description of the figures

[0030] Other features and advantages of the invention will become apparent from the following description, with reference to the attached figures. [Fig.1] Fig.1 illustrates a hybrid drive subset of a vehicle according to a first embodiment. [Fig.2] Fig.2 illustrates a hybrid drive subset of a vehicle according to a second embodiment. [Fig.3] Fig.3 illustrates a hybrid drive subset of a vehicle according to a third embodiment. [Fig.4] Fig.4 illustrates a hybrid drive subset of a vehicle according to a fourth embodiment. [Fig.5] Fig.5 illustrates a hybrid drive subset of a vehicle according to a fifth embodiment.

[0031] For clarity, identical or similar elements are identified by identical reference signs throughout the figures. DETAILED description of implementation methods

[0032] Figure 1 illustrates a hybrid sub-assembly 10 of a vehicle drive system, comprising a primary shaft 12 intended to be driven by a main engine 14 of the vehicle, for example a heat engine, a secondary shaft 16 intended to drive an assembly of one or more drive wheels of the vehicle (not shown), and a transmission 18.

[0033] The connection of the main motor 14 to the primary shaft 12 may include a clutch 20 of any suitable type, for example a slip clutch. The connection of the secondary shaft 16 to the vehicle wheels may include one or more drive axles.

[0034] The transmission 18, housed within a cavity 22 in a transmission casing 24, comprises an intermediate shaft 26 to which intermediate gears 28, 30, 32, 34, 36 are rotationally fixed. Two primary gears 38, 40, coaxial with the primary shaft 12, each form a gear train with a corresponding gear 28, respectively 30, among the intermediate gears. The meshing of the gear trains 38, 28 and 40, 30 between primary gears 38, 40 and the corresponding intermediate gears 28, 30 is permanent. A double synchronizer 41 with three positions allows either of the primary gears 38, 40 to be coupled to the primary shaft 12, and provides a neutral position in which neither of the primary gears 38, 40 is coupled to the primary shaft 12.

[0035] Secondary gears 42, 44, 46, coaxial with the secondary shaft 16, each also form a gear train with a corresponding gear 32, 34, 36, respectively, from among the intermediate gears, one of the gear trains being reversing and comprising an intermediate gear 48 to achieve a reverse gear ratio. The meshing of the gear trains formed by the secondary gears 42, 44, 46 and the corresponding intermediate gears 32, 34, 36 is permanent. A three-position dog clutch coupling without synchronizers 50, positioned between two of the secondary wheels 44, 46, allows either to couple to the secondary shaft 16 one or the other of the two associated secondary wheels 44, 46, or, in an intermediate neutral position, to keep the associated secondary gears 44, 46 decoupled from the secondary shaft 16.

[0036] In this embodiment, the axis of revolution 100 of the primary shaft 12 is aligned with the axis of revolution 200 of the secondary shaft 16, which allows the primary end gear 40 to be used alternately as a primary gear, connected to the primary shaft 12 by the synchronizer 41, or as a secondary gear connected to the secondary shaft 16. For this purpose, a three-position dog clutch 52 without synchronizers, positioned between the primary end gear 40 and the secondary gear 42, allows either the primary end gear 40 or the secondary wheel 42, and also allows, in an intermediate neutral position, to keep the primary end wheel 40 and the secondary wheel 42 decoupled from the secondary shaft 16.

[0037] A transmission 18 with six forward gears and potentially two reverse gears is thus established, which can, if necessary, be coupled at the output of the secondary shaft 16 to an epicyclic gear train (not illustrated) in order to obtain a twelve-speed gearbox.

[0038] Remarkably, the hybrid drive sub-assembly 10 is equipped with an electromotor unit 5 comprising a reversible electric machine 56, whose output shaft 57 rotates around an axis of revolution 300, and a coupling device 58, comprising in this example a three-position dog clutch mechanism 59 without synchronizer and two gear reduction trains 60, 62, 64, 66, 68. In a connection position to the intermediate shaft 26, also called the intermediate coupling position, the coupling device 58 achieves a rotational coupling of the output shaft 57 with a so-called intermediate speed reducer 260 comprising here a gear 60 which permanently meshes with a gear 62 fixed to the intermediate shaft 26.In a secondary shaft connection position, also called the secondary coupling position, the coupling device 58 connects the output shaft 57 to a secondary speed reducer 264, comprising a gear 64 that permanently meshes with a reversing gear 66, which itself permanently meshes with a gear 68 fixed to the secondary shaft 16. Remarkably, the reversing gear 66 can be guided in rotation by a guide bearing 69 coaxial with the intermediate shaft 26. The intermediate shaft 26 can then support the guide bearing 69. Finally, the coupling device 58, in a neutral position, keeps the output shaft 57 decoupled from the gears 60, 64.Within the coupling device 58, the transition from the intermediate coupling position to the secondary coupling position is achieved via the coupling mechanism 59 controlled by a control unit 76.

[0039] Where applicable, the intermediate shaft 26 is equipped with a power take-off 68, intended to allow the coupling of one or more vehicle accessories, for example a winch, a pump, or a tool. The power take-off 68 may, for example, be a transmission shaft comprising an external connection interface, for example a spline.

[0040] The motor shaft 57 illustrated in [Fig. 1] is integral with the rotor of the reversible electric machine 56 and constitutes a motor shaft. Alternatively, the reversible electric machine may incorporate a gearbox between the motor shaft and the output shaft 57.

[0041] The reversible electric machine 56 is powered by a battery 70 per via a bidirectional current converter 72, which allows the reversible electric machine 56 to be powered as a motor, and conversely, to rotate the reversible electric machine 56 as a generator to power the battery 70.

[0042] The reversible electric machine 56 is preferably a high-voltage machine, supplied for example at a nominal voltage between 300 Volts and 800 Volts, capable of delivering significant torque and power, as will be discussed later.

[0043] The control unit 76 allows the reversible electric machine 56 and its coupling device 58 to be controlled. Sensors 78, 80, 82 are connected to this control unit to measure the rotational speed of the output shaft 57, the intermediate shaft 26, and the secondary shaft 16, or the rotational speeds of elements permanently driven by these shafts. This control unit 76 can be integrated into a robotic control of the transmission 18, which controls the opening and closing of the synchronizers 41, the dog clutch mechanisms 50, 52, and, where applicable, the main clutch 20, to respond to a torque or speed command.

[0044] The electric machine 56 allows for several modes of operation, as will be discussed later.

[0045] Figure 2 illustrates a hybrid subassembly 10 according to a second embodiment of the invention, which differs from the embodiment shown in Figure 1 in that the coupling device 58 comprises, in addition to the three-position dog clutch coupling mechanism 59, a two-position dog clutch coupling mechanism 159, which provides a rotational coupling of the output shaft 57 with a second intermediate speed reducer 360 comprising a gear 160 that permanently meshes with a gear 162 fixed to the intermediate shaft 26. The transmission ratio achieved by the gearing of the gears 160, 162 is different from the transmission ratio of the gearing of the gears 60, 62. The coupling mechanism 159, in a neutral position, keeps the output shaft 57 decoupled from the gear 160.

[0046] A person skilled in the art will understand, without the need for detailed illustration, that it would be possible, if necessary, to multiply the transmission ratios between the output shaft 57 and the intermediate shaft by adding speed reducers between the coupling mechanisms 59, 159 and the intermediate shaft 26. Similarly, it would be possible to multiply the transmission ratios between the output shaft 57 and the secondary shaft 16 by adding coupling mechanisms and speed reducers between the output shaft 57 and the secondary shaft 16.

[0047] The coupling mechanisms 59, 159 of the coupling device 58 can be of any type, in particular dog clutch with or without synchronization or friction clutch. Figure 3 illustrates a third embodiment of the invention, which differs The embodiment shown in [Fig. 1] differs from the one shown in [Fig. 4] by the fact that the coupling device 58 includes a coupling mechanism of the wet friction double clutch type 259. In [Fig. 4], the coupling device 58 includes a coupling mechanism of the wet friction triple clutch type 359, achieving the same transmission ratios as the embodiment shown in [Fig. 2]. In [Fig. 5], a fifth embodiment of the invention is illustrated, which differs from the embodiment shown in [Fig. 3] by the addition of a reduction gear, here an epicyclic gear train 564, between the gear 64 and the secondary shaft 16. Depending on the type of epicyclic gear train chosen, the reversing gear for the gears 66, 68 may remain necessary, or be integrated into the epicyclic gear train.

[0048] The various embodiments described have in common a coupling device 58 capable of taking at least one so-called intermediate coupling position in which the reversible electric machine 56 is kinematically linked to the intermediate shaft, and at least one secondary coupling position in which the reversible electric machine 56 is kinematically linked to the secondary shaft 16 without passing through the intermediate shaft 26. These various couplings can be used to achieve a wide variety of operating modes, as will now be discussed.

[0049] First of all, several modes of operation can be implemented while the coupling device 58 connects the output shaft 57 to the intermediate shaft 26.

[0050] In a transient mode of synchronizing the intermediate shaft during a gear change, the coupling device 58 is positioned in the intermediate coupling position, the main motor 14 is disengaged from the intermediate shaft 26 either at the clutch 20 or at the dog clutch mechanism 41, then the reversible electric machine 56 is controlled so as to bring the intermediate shaft 26 to a set speed allowing the engagement of the secondary gear before re-coupling the main motor 14 to the intermediate shaft 26. During these transient phases, the reversible electric machine 56 thus makes it possible to adapt the speed of revolution of the intermediate shaft to the synchronization requirements during the switching of the dog clutch mechanisms 50, 52 or the synchronizers 41.During these phases, the reversible electric machine can be used alternately as an electric motor to increase the rotational speed of the intermediate shaft 26 or as a generator to decrease this speed. This adaptation of the speed of the intermediate shaft 26 makes it possible to reduce the dog clutch or synchronization times, without resorting to a gearbox brake.

[0051] In a charging mode, one of the primary gears 38, 40 is coupled to the primary shaft 12, the main motor 14 is powered so as to drive the primary shaft 12 and to exert a main motor torque on the intermediate shaft 26, one po The coupling device 58 is positioned in the intermediate coupling position, and kinetic energy is converted into electrical energy by the reversible electric machine operating as a generator. Recharging can take place while the intermediate shaft 26 drives the secondary shaft 16 or without a connection to the secondary shaft 16.

[0052] In a boost mode, one of the secondary gears 42, 44, 46 is coupled to the secondary shaft 16, one of the primary gears 38, 40 is coupled to the primary shaft, the main motor 14 is powered so as to drive the primary shaft 12 and exert a main motor torque on the intermediate shaft 26, and the coupling device 58 is positioned in the intermediate coupling position or one of the intermediate coupling positions if there are several, and the reversible electric machine generates a boost motor torque on the intermediate shaft, with the same sign as the main motor torque. The additional power input for vehicle traction is achieved with one gear ratio (for the embodiments shown in Figures 1, 3, and 5), two gear ratios (for the embodiments shown in Figures 2 and 4), or even more.

[0053] In a pure electric drive mode passing through the intermediate shaft 26, the coupling device 58 is positioned in the intermediate coupling position and the main motor 14 is uncoupled from the intermediate shaft 26 while one of the secondary gears 42, 44, 46 is coupled to the secondary shaft 16, then the reversible electric machine is controlled according to a vehicle speed setpoint.As a guideline, to implement such an electric vehicle drive system, it is advantageous for the reversible electric motor to be able to continuously develop a motor torque exceeding 300 Nm, and preferably exceeding 350 Nm, within a speed range exceeding 1000 rpm, and preferably exceeding 2000 rpm, with a lower limit below 6000 rpm, and preferably below 5000 rpm, and an upper limit above 6000 rpm, preferably above 7000 rpm, and preferably above 9000 rpm. With such an operating range, combined with several transmission ratios between 4 and 8 achieved by the meshing of gears 32 and 42, 34 and 44, 60, 62, and, where applicable, 160 and 162, electric operation of the vehicle in urban driving mode is conceivable.

[0054] In a regenerative braking mode passing through the intermediate shaft, the coupling device 58 is positioned in the intermediate coupling position, the main motor 14 is decoupled from the intermediate shaft 26, at the clutch 20 or the synchronizers 41, one of the dogs 50, 52 is engaged to connect the intermediate shaft 26 to the secondary shaft 16 and the reversible electric machine 56 is driven to operate as a generator.

[0055] In a hybrid motor braking mode, the coupling device 58 is positioned in the intermediate coupling position, a kinematic link is maintained between the main motor 14, the intermediate shaft 26, and the secondary shaft 16, part of the kinetic energy transmitted by the secondary shaft 16 is converted into electrical energy by the reversible electric machine 56 operating as a generator, and part of the kinetic energy transmitted by the secondary shaft 16 is converted into heat by the main motor 14, which develops a resisting torque. This operating mode makes it possible to achieve a higher braking torque than with the main motor 14 alone.

[0056] The reversible electric machine 56 can also be used as a motor to drive the power take-off 68 while the transmission 18 is in the neutral position to interrupt the connection between the intermediate shaft 26 and the primary shaft 12 on the one hand, and between the intermediate shaft 26 and the secondary shaft 16 on the other hand.

[0057] Particularly advantageously, other modes of operation can be envisaged while the coupling device 58 connects the output shaft 57 to the intermediate shaft 26.

[0058] A transient mode of maintaining traction during a gear change can thus be implemented, in which the coupling device 58 is positioned in the secondary coupling position, the main motor 14 is uncoupled from the intermediate shaft 26, and the reversible electric machine 56 is controlled so as to generate a motor torque on the secondary shaft 16 or to minimize a speed variation of the secondary shaft while a gear change of the transmission 18 is controlled between the main motor 14 and the intermediate shaft 26 and / or between the intermediate shaft 26 and the secondary shaft 16.

[0059] A pure regenerative braking mode without the intermediate shaft 26 can also be envisaged, in which the coupling device is positioned in the secondary coupling position, the secondary shaft 16 is uncoupled from the intermediate shaft 26 by acting on the dog clutch mechanisms 50, 52 and electrical energy is generated with the reversible electric machine 56 operating as a generator. To optimally achieve this regenerative braking mode without the main motor, it is advantageous that the reversible electric machine be able to develop a resisting torque greater than 400 Nm and preferably greater than 450 Nm in a speed range of more than 3000 rpm, and preferably more than 4000 rpm with a lower limit that is less than 6500 rpm, and preferably less than 6000 rpm and an upper limit that is greater than 9000 rpm, and preferably greater than 10000 rpm, for at least 30 seconds.

[0060] The transient mode of maintaining traction during a gear change and the pure regenerative braking mode without the intermediate shaft 26 are modes of operation transient operation, not intended to last more than thirty seconds. As an indication, with a transmission ratio of around 8 between the output shaft 57 and the secondary shaft 16, it is advantageous to size the reversible electric machine to develop a resisting torque greater than 400 Nm and preferably greater than 450 Nm in a speed range of more than 3000 rpm, and preferably more than 4000 rpm having a lower limit which is less than 6500 rpm, and preferably less than 6000 rpm and an upper limit which is greater than 9000 rpm, and preferably greater than 10000 rpm, for 30 seconds.

[0061] A direct electric drive mode without the intermediate shaft 26 can finally be implemented, in which the coupling device 58 is positioned in the secondary coupling position and the intermediate shaft 26 is disengaged from the secondary shaft 16 at the dog clutch mechanisms 50, 52, the reversible electric machine acting in a driving or regenerative manner depending on the acceleration or braking requirements. This operating mode is less flexible than the electric drive mode with the intermediate shaft since the plurality of transmission ratios of the gearbox 18 is not available. However, it can be used in conjunction with the latter, offering a higher direct transmission ratio between the output shaft 57 and the secondary shaft 16 than the transmission ratios using the gearbox 18.As an example, two ratios with a value of around 4 and 6 respectively can be developed with the dog clutches 50, 52 of the transmission box 18 combined with the gear train 60, 62 of the coupling device 58, and an additional transmission ratio with a value of around 8 by the gear train 64, 66, 68 of the coupling device 58.

[0062] Naturally, the examples shown in the figures and discussed above are given by way of illustration only and are not intended to be limiting. It is explicitly intended that the different embodiments illustrated can be combined to propose others.

[0063] According to an unillustrated variant, the power take-off element 68 is positioned on the output shaft 57 of the reversible electric machine 56.

Claims

Demands

1. Hybrid sub-assembly (10) of a vehicle drive, comprising: - at least one primary shaft (12); - at least one secondary shaft (16); - a transmission (18) comprising at least one intermediate shaft (26) separate from the primary shaft (12) and the secondary shaft (16) and gear trains (38, 28, 40, 30, 32, 42, 36, 48, 44, 46) for achieving several transmission ratios between the primary shaft (12) and the secondary shaft (16) via the intermediate shaft (26); - an electromotor set comprising at least one reversible electric machine (56), and a coupling device (58) which, in at least one intermediate coupling position, kinematically links an output shaft (57) of the reversible electric machine (56) to the intermediate shaft (26), in which the coupling device, in a secondary coupling position,kinematically links the output shaft (57) of the reversible electric machine (56) to the secondary shaft (16) without passing through the intermediate shaft (26), the coupling device (58) comprising at least one coupling mechanism (59, 159, 259, 359) permanently kinematically linked to the output shaft (57) of the reversible electric machine (56), an intermediate speed reducer (260, 360) permanently kinematically linked to the intermediate shaft (26) and a secondary speed reducer (264, 564) permanently kinematically linked to the secondary shaft (16), characterized in that the secondary speed reducer (264, 564) comprises a reversing gear (66) guided in rotation by a guide bearing (69) coaxial with the intermediate shaft (26).

2. Hybrid subassembly (10) according to claim 1, characterized in that the coupling device (58), in at least one uncoupling position, kinematically uncouples simultaneously the output shaft (57) of the reversible electric machine (56) to the intermediate shaft (26) and to the secondary shaft (16).

3. Hybrid subset (10) according to any one of the claims

4. previous, exhibiting one or more of the following characteristics: - the reversible electric machine (56) is capable of continuously developing a motor torque greater than 300 Nm in a speed range of more than 1000 rpm including having a lower limit which is less than 6000 rpm and an upper limit which is greater than 6000 rpm; - the reversible electric machine (56) is capable of developing a resisting torque greater than 400 Nm in a speed range of more than 3000 rpm having a lower limit which is less than 6500 rpm and an upper limit which is greater than 9000 rpm, for 30 seconds; - the reversible electric machine (56) is capable of developing a motor torque greater than 50 Nm in a speed range of more than 5500 rpm having a lower limit which is less than 5000 rpm and an upper limit which is greater than 10000 rpm for 5 seconds in transient gear change regime. Hybrid subassembly (10) according to any one of the preceding claims, characterized in that the coupling device (58) in the intermediate coupling position kinematically links the output shaft (57) of the reversible electric machine (56) to the intermediate shaft (26) with an intermediate transmission ratio, the coupling device (58) in the secondary coupling position kinematically links the reversible electric machine (56) to the secondary shaft (16) with a secondary transmission ratio, and in that at least one of the following criteria is met: - the secondary transmission ratio is greater than 6, and preferably greater than or equal to 8; - the upper intermediate transmission ratio 4, and preferably greater than or equal to 6 between the intermediate shaft (26) and the output shaft (57) of the reversible electric machine (56); - the secondary transmission ratio is strictly greater than the intermediate transmission ratio, preferably with a factor greater than or equal to 1.5 between secondary transmission ratio and intermediate transmission ratio.

5.

6.

7. Hybrid subassembly (10) according to claim 4, characterized in that at least one of the following criteria is met: - the coupling device (58), in an additional intermediate coupling position, kinematically links the reversible electric machine (56) to the intermediate shaft (26) with an additional intermediate transmission ratio distinct from the intermediate transmission ratio; Hybrid subassembly (10) according to any one of the preceding claims, characterized in that it further comprises a power take-off element (68), capable of being driven at least by the reversible electric machine (56), preferably in one of the following ways: - the power take-off unit (68) is permanently kinematically linked to the intermediate shaft (26); - the power take-off element (68) is kinematically linked to the output shaft (57) of the reversible electric machine (56) via the coupling device (58) in the intermediate coupling position. Hybrid subassembly (10) according to any one of the preceding claims, characterized in that the output shaft (57) of the reversible electric machine (56) has an axis of revolution (300) parallel to an axis of revolution of the intermediate shaft (26), one or more of the following features preferably being realized: - the axis of revolution (300) of the output shaft (57) coincides with the axis of revolution (200) of the intermediate shaft (26); - the axis of revolution (300) of the output shaft (57) is distant from the axis of revolution (200) of the intermediate shaft (26); - the axis of revolution (300) of the output tree (57) is distant from one axis of revolution (100) of the primary tree (12); - the axis of revolution (300) of the output tree (57) is distant from one axis of revolution of the secondary tree (16).

8. Hybrid subassembly according to any one of the preceding claims, characterized in that the coupling device (58) comprises an epicyclic gear train (564) kinematically arranged between the output shaft (57) and the secondary shaft (16).

9. Hybrid subassembly according to any one of the preceding claims, characterized in that the coupling device (58) comprises one or more of the following coupling mechanisms: - a dog clutch mechanism (59, 159), - a synchronizer mechanism, - a clutch mechanism (259, 359), preferably a friction clutch mechanism, preferably wet, - a double friction clutch (259), preferably wet, - a triple friction clutch (359), preferably wet.

10. Hybrid subassembly (10) according to any one of the preceding claims, characterized in that it comprises a control unit (76) of the reversible electric machine (56) and of the coupling device (58), and sensors (78, 80, 82) capable of generating a signal representative of a speed of revolution of the intermediate shaft (26) or of a component kinematically linked to it, a signal representative of a speed of revolution of the secondary shaft (16) or of a component kinematically linked to it, and a signal representative of a speed of revolution of the reversible electric machine (56) or of a component kinematically linked to it.

11. Hybrid engine group comprising a main engine (14), preferably an internal combustion engine, with a main drive shaft, characterized in that it further comprises a hybrid sub-assembly (10) according to any one of the preceding claims, the main drive shaft being connected to the primary shaft (12) directly or via a clutch (20) or a torque converter.

12. Hybrid engine assembly according to the preceding claim, the hybrid subassembly (10) being, according to claim 10, characterized in that the control unit (76) of the coupling device (58) is operational for controlling one or more of the following operating modes: - a transient traction maintenance mode during a gear change, in which the device is positioned coupling (58) in the secondary coupling position, the main motor (14) is uncoupled from the intermediate shaft (26), and the reversible electric machine (56) is controlled so as to generate a motor torque on the secondary shaft (16) or to minimize a speed variation of the secondary shaft (16) while a gear change of the transmission (18) is controlled; - a pure regenerative slowing mode without the intermediate shaft (26), in which the coupling device (58) is positioned in the secondary coupling position, the secondary shaft (16) is uncoupled from the intermediate shaft (26) and electrical energy is generated with the reversible electric machine (56) operating as a generator; - a direct electric drive mode without the intermediate shaft (26), in which the coupling device (58) is positioned in the secondary coupling position, the intermediate shaft (26) is uncoupled from the secondary shaft (16), and the reversible electric machine (56) is the driving machine.

13. Hybrid powertrain according to the preceding claim, characterized in that the control unit (76) is operational for controlling one or more of the following operating modes: - a reinforcement mode, in which the transmission box (18) performs one of the transmission ratios between the primary shaft (12) and the secondary shaft (16) via the intermediate shaft (26), the main motor (14) is supplied so as to drive the primary shaft (12) and to exert a main motor torque on the intermediate shaft (26), the coupling device (58) is positioned in the intermediate coupling position, and the reversible electric machine (56) generates a reinforcing motor torque on the intermediate shaft (26), of the same sign as the main motor torque; - a charging mode, in which the transmission (18) is positioned so as to connect the primary shaft (12) to the shaft intermediate (26), the main motor (14) is powered so as to drive the primary shaft (12) and to exert a main motor torque on the intermediate shaft (26), the coupling device (58) is positioned in the intermediate coupling position, and kinetic energy is transformed into electrical energy with the reversible electric machine (56) operating as a generator; a transient mode of synchronization of the intermediate shaft (26) during a passage of one of the transmission ratios of the transmission box (18), in which the coupling device (58) is positioned in the intermediate coupling position, the main motor (14) is uncoupled from the intermediate shaft (26), then the reversible electric machine (58) is controlled so as to bring the intermediate shaft (26) to a set speed allowing the engagement of the secondary gear before recoupling the main motor (14) to the intermediate shaft (26); an indirect electric drive mode, in which the coupling device (58) is positioned in the intermediate coupling position and the main motor (14) is uncoupled from the intermediate shaft (26) while the intermediate shaft (26) is kinematically linked to the secondary shaft (16), then the reversible electric machine is controlled according to a vehicle speed setpoint; a regenerative braking mode by the intermediate shaft (26), in which the coupling device (58) is positioned in the intermediate coupling position, the main drive shaft (12) is decoupled from the intermediate shaft (26) and the reversible electric machine (56) is driven to operate as a generator; a hybrid engine braking mode, in which the coupling device (58) is positioned in the intermediate coupling position, one of the transmission ratios between the primary shaft and the secondary shaft (16) via the intermediate shaft (26) is engaged, the primary shaft (12) is kinematically linked to the main drive shaft, and kinetic energy is converted into electrical energy with the reversible electric machine (56) operating as a generator and kinetic energy is transformed into heat with the main motor developing a resisting torque; a power take-off drive mode (68), in which the coupling device (58) is positioned in the intermediate coupling position and the main motor is uncoupled from the intermediate shaft, the intermediate shaft (26) from the secondary shaft (16), and then the reversible electric machine (56) is controlled to drive a power take-off (68) coupled to the intermediate shaft (26).

14. A hybrid drive method for a vehicle comprising a hybrid engine unit according to claim 11, characterized in that, with a control unit (76) of the coupling device (58), one or more of the following operating modes are controlled: - a transient mode of maintaining traction during a gear change, in which the coupling device (58) is positioned in the secondary coupling position, the main motor (14) is uncoupled from the intermediate shaft (26), and the reversible electric machine (56) is controlled so as to generate a motor torque on the secondary shaft (16) or to minimize a speed variation of the secondary shaft (16) while a gear change of the transmission (18) is controlled; - a pure regenerative slowing mode without the intermediate shaft (26), in which the coupling device (58) is positioned in the secondary coupling position, the secondary shaft (16) is uncoupled from the intermediate shaft (26) and electrical energy is generated with the reversible electric machine (56) operating as a generator; - a direct electric drive mode without the intermediate shaft (26), in which the coupling device (58) is positioned in the secondary coupling position, the intermediate shaft (26) is uncoupled from the secondary shaft (16), and the reversible electric machine (56) is the driving machine.

15. Hybrid drive method according to the preceding claim, characterized in that, with the control unit (76), one or more of the following operating modes are controlled: - a reinforcement mode, in which the transmission box (18) performs one of the transmission ratios between the primary shaft (12) and the secondary shaft (16) via the intermediate shaft (26), the main motor (14) is supplied so as to drive the primary shaft (12) and to exert a main motor torque on the intermediate shaft (26), the coupling device (58) is positioned in the intermediate coupling position, and the reversible electric machine (56) generates a reinforcing motor torque on the intermediate shaft (26), of the same sign as the main motor torque; - a charging mode, in which the transmission box (18) is positioned so as to connect the primary shaft (12) to the intermediate shaft (26), the main motor (14) is supplied so as to drive the primary shaft (12) and to exert a main motor torque on the intermediate shaft (26), the coupling device (58) is positioned in the intermediate coupling position, and kinetic energy is transformed into electrical energy with the reversible electric machine (56) operating as a generator; - a transient mode of synchronizing the intermediate shaft (26) during a shift of one of the transmission ratios of the gearbox (18), in which the coupling device (58) is positioned in the intermediate coupling position, the main motor (14) is uncoupled from the intermediate shaft (26), then the reversible electric machine (56) is controlled so as to bring the intermediate shaft (26) to a set speed allowing the engagement of the secondary gear before recoupling the main motor (14) to the intermediate shaft (26); - an indirect electric drive mode, in which the coupling device (58) is positioned intermediate coupling and the main motor (14) is uncoupled from the intermediate shaft (26) while the intermediate shaft (26) is kinematically linked to the secondary shaft (16), then the reversible electric machine is controlled according to a vehicle speed setpoint; a regenerative braking mode by the intermediate shaft (26), in which the coupling device (58) is positioned in the intermediate coupling position, the main drive shaft (12) is decoupled from the intermediate shaft (26) and the reversible electric machine (56) is driven to operate as a generator; a hybrid motor braking mode, in which the coupling device (58) is positioned in the intermediate coupling position, one of the transmission ratios between the primary shaft and the secondary shaft (16) passing through the intermediate shaft (26) being engaged, the primary shaft (12) being kinematically linked to the main motor shaft, and kinetic energy is converted into electrical energy with the reversible electric machine (56) operating as a generator and kinetic energy is converted into heat with the main motor developing a resisting torque; a power take-off drive mode (68), in which the coupling device (58) is positioned in the intermediate coupling position and the main motor is uncoupled from the intermediate shaft, the intermediate shaft (26) from the secondary shaft (16), and then the reversible electric machine (56) is controlled to drive a power take-off (68) coupled to the intermediate shaft (26).

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