Transmission device for a vehicle axle

Abstract

Transmission device for a vehicle axle, comprising a first driving wheel (11) intended to be driven by a first driving member M1, a second driving wheel (12) intended to be driven by a second driving member (M2), a left wheel shaft (31), a right wheel shaft (32), a main axle shaft (10) interposed between the left and right wheel shafts, first left and right coupling members (41, 42) capable of selectively engaging in rotation respectively the left and right wheel shaft (31, 32) with the main axle shaft, two planetary gears (21, 22), each planetary gear engaging by toothing permanently with the first driving wheel (11) and with the second driving wheel (12), second left and right coupling members (51, 52) capable of selectively engaging in rotation respectively the left and right wheel shaft (31, 32) with the first driving wheel (11), and respectively the second driving wheel (12).Figure for abstract: Fig 1.

Description

Title of the invention: Transmission device for a vehicle axle Technical field

[0001] The present invention relates to transmission devices for vehicle axles. In particular, it concerns an axle with essentially electric motorization. Such an axle may be suitable for a 4-wheel vehicle, although other applications are not excluded. One of the intended modes of use of the vehicle in question is the so-called "Offroad" mode which involves traveling at very low speed in difficult terrain with the crossing of obstacles and / or ruts. Prior art

[0002] Document WO2021126333 discloses an axle with 2 electric motors equipped with a differential lock. However, it is noted that for very low speed maneuvers in “Offroad” mode, the electric motors involved rotate at very low speed (or are even blocked), which poses a problem of heating of the control circuits and, consequently, this is detrimental to the performance and lifespan of the system.

[0003] The inventors sought to propose a flexible and versatile solution to improve the behavior of the electrically powered axle in off-road mode while allowing other modes of use, including road use. Statement of the invention

[0004] For this purpose, according to the present disclosure, there is provided here a transmission device for a vehicle axle having an axle shaft, the device comprising: • a first driving wheel intended to be driven by a first motor member, • a second driving wheel intended to be driven by a second motor unit, • a left wheel shaft, intended to be coupled to a left axle wheel, • a straight wheel shaft, intended to be coupled to a straight axle wheel, • a main axle shaft, mounted to rotate around the axle axis and interposed between the left and right wheel shafts, • a first left coupling member capable of selectively engaging in rotation the left wheel shaft with the main axle shaft, directly or via a reducer, • a first right coupling member capable of selectively engaging in rotation the right wheel shaft with the main axle shaft, directly or via a reducer, • at least two planet gears, the main axle shaft acting as a planet carrier for the at least two planet gears, each of the at least two planet gears providing permanent tooth engagement with the first drive wheel and with the second drive wheel, • a second left coupling member capable of selectively engaging the left wheel shaft in rotation with the first driving wheel, directly or via a reducer, • a second right coupling member capable of selectively engaging in rotation the right wheel shaft with the second driving wheel, directly or via a reducer.

[0005] Thanks to these arrangements, the first left coupling member and the first right coupling member make it possible to secure the left and right shafts and thus obtain the differential locking function on the axle, in particular for "off-road" situations. Furthermore, in a road situation, the left and right wheels can be driven independently respectively by the left and right motors, either in a conventional manner or in a particular manner with vectoring of the torques applied to the wheels. In addition, the axle can be put into freewheel mode, to minimize drag, or into energy recovery mode in the context of regenerative electric braking. In addition, the device presented allows a degraded mode called 'limp home', in which traction can be obtained on both wheels even in the event of failure of one of the two motors.

[0006] In summary, the structure of the device as well as appropriate selective control of the 4 coupling members provide general versatility and access to multiple operating modes of the axle.

[0007] It should be noted that the axle axis A does not necessarily coincide with the wheel axis. There may be a final reduction between the axle axis and the wheel axis which leads to a wheel axis offset from the axle axis. There may also be a suspension connection to the ground with relative vertical travel.

[0008] It is also noted that, in the above, the term 'axle wheel' designates the vehicle wheel in contact with the ground while the term 'drive wheel' designates a gear wheel in the kinematics of the axle.

[0009] In various embodiments of the invention, one and / or the other of the following arrangements may optionally be used, taken individually or in combination.

[0010] RI a According to one aspect, each of the two planet gears is permanently toothedly engaged with both the first drive wheel and the second drive wheel. This creates a structure similar to a conical or spherical differential with teeth inclined at 45° to the axis. However, a flat structure is not excluded.

[0011] R2 According to one aspect, the first left coupling member and / or the first right coupling member may be a hydraulic clutch. Opposite discs are pressed against each other by a controlled hydraulic pressure; there may be several pairs of discs in mutual interaction. Such a hydraulic clutch may be controlled to allow a certain amount of slip between the two respective rotating parts.

[0012] R2b According to another aspect, the first left coupling member and / or the first right coupling member may be a mechanical dog clutch system, for example with an axially movable grooved sleeve. This forms a loss-free solution with excellent efficiency.

[0013] R3 According to one aspect, the second left coupling member and / or the second right coupling member may be a hydraulic clutch. Here too, these may be discs arranged opposite each other which are pressed against each other by a controlled hydraulic pressure. Here too, such a hydraulic clutch may in certain cases be controlled to allow a certain sliding between the 2 respective rotating parts.

[0014] R3b According to another aspect, the second left coupling member and / or the second right coupling member may be a mechanical dog clutch system, for example with an axially movable grooved sleeve.

[0015] R4 According to one aspect, the rotational speed (V10) of the main axle shaft is the algebraic half-sum of the rotational speed (VI1) of the first driving wheel and the rotational speed (V12) of the second driving wheel. If the first driving wheel and the second driving wheel rotate in the same direction, and at the same speed, then the main axle shaft also rotates at the same speed. If the first driving wheel and the second driving wheel rotate in opposite directions and at the same speed, then their effects cancel each other out and the main axle shaft does not rotate (zero rotational speed); it is this characteristic that is used for off-road mode situations in quasi-static or very low speed. Using the notations above, the rotational speeds verify the equation V10 = (Vll+V12) / 2.

[0016] R5 According to one aspect, it is provided that for a track / offroad mode, with the first left and right coupling members engaged (axle differential lock function present), and with a speed of the main axle shaft lower than a first predefined threshold SV1, the rotational speed (V11) of the first driving wheel and the rotational speed (V12) of the second driving wheel are each greater, in absolute value, than a second predefined threshold SV2, and SV2>SV1. Thanks to the device presented, we can choose rotation speeds for each of the 2 motors sufficiently far from zero speed and this for an output shaft speed close to 0. This avoids any risk of heating the electronic control stages of the motors and avoids possible "derating" (voluntary degradation of performance to protect the equipment).

[0017] R6 According to one aspect, it is provided that when the four coupling members are in the uncoupled state (clutch open), the right and left wheels are in a freewheel configuration. Whereby the drag introduced by the presence of the axle, in its non-motorized state, is minimized. This mode is advantageous for driving, for example, on a highway and is favorable to energy savings for travel.

[0018] R7 According to one aspect, it may be provided that the first driving wheel and the second driving wheel are mounted to rotate about the axle axis, and the first driving wheel and the second driving wheel are arranged on either side, symmetrically with respect to an axle median plane. This naturally balances the torques involved and promotes the right-left balance of the assembly.

[0019] R8 According to one aspect, the device may further include the first drive member and the second drive member, the first and second drive members being electric motors. The axle forms a self-contained motorized assembly, with a power supply and local or remote electronic control.

[0020] R8b According to one aspect, it is not excluded to use hydraulic motors instead of electric motors.

[0021] R9 According to one aspect, each of the first and second motor members has a rotor having an axis coincident with the axle axis (A). As a result, the integration of the motors in the axle is improved and the general compactness of the solution is improved.

[0022] RIO According to one aspect, the main axle shaft may be rigid in rotation with an auxiliary toothed wheel which may be selectively driven by a longitudinal shaft of the vehicle from another axle or from an auxiliary, electric or thermal, motor unit. The proposed axle may thus be suitable for a multitude of vehicle applications with two or more axles.

[0023] RI 1 According to one aspect, there may be provided, for a left side (respectively right), a planetary gear train interposed between on the one hand the first and second coupling members (41, 51) and on the other hand the wheel shaft.

[0024] RI 1b According to one aspect, the planetary gear train is of the “Ravigneaux” type. Brief description of the drawings

[0025] Other characteristics and advantages of the invention will become apparent upon reading of the description which follows. This is purely illustrative and must be read in conjunction with the attached drawings in which:

[0026] [Fig.l] [Fig.l] schematically illustrates an electrically powered axle according to a first embodiment of the present invention,

[0027] [Fig.2] [Fig.2] schematically illustrates a road operating mode with independence of the traction controls applied to the wheels,

[0028] [Fig.3] [Fig.3] schematically illustrates another mode of operation with vectorization of the drive commands applied to the wheels,

[0029] [Fig.4] [Fig.4] schematically illustrates another road operating mode with a freewheel function on the axle,

[0030] [Fig.5] [Fig.5] schematically illustrates another mode of operation, in the event of failure of one of the motor components,

[0031] [Fig.6] [Fig.6] schematically illustrates another mode of operation, called track or “offroad”,

[0032] [Fig.7] [Fig.7] schematically illustrates an electrically powered axle according to a second embodiment of the present invention,

[0033] [Fig.8] [Fig.8] schematically illustrates an electrically powered half axle according to a third embodiment of the present invention,

[0034] [Fig.9] [Fig.9] shows a detailed view of a planetary gear train interposed between the first and second coupling members and the wheel shaft, useful in particular in the context of the third and fourth embodiments,

[0035] [Fig. 10] [Fig. 10] schematically illustrates an electrically powered half axle according to a fourth embodiment of the present invention. Description of the embodiments

[0036] In the various figures, the same references designate identical or similar elements. For reasons of clarity of the description, certain elements are not necessarily represented to scale.

[0037] Furthermore, it should be noted that, in the figures, the axle housing has not been shown to facilitate reading of the figures. Similarly, the lubrication system has not been shown. With regard to the bearings, the various ball or roller bearings usually used have not been shown except for some symbolically in dotted lines. Similarly, it should be noted that suspension and / or steering kinematics may be provided at the wheel level, not shown in the figures, but compatible with the present disclosure.

[0038] The figures show an electrically powered axle. In the example illustrated, this electrically powered axle comprises at least two electric motors. However, it could be equipped with more than two electric motors.

[0039] In an alternative embodiment, instead of using electric motors, hydraulic motors can be used. Thus, the generic term "motor unit" can be used to designate either an electric motor or a hydraulic motor.

[0040] This axle may be suitable for a four-wheeled vehicle, although other applications are not excluded, for example three-wheeled vehicles or vehicles with more than four wheels. In the vehicle in question, there may be another axle of the same type or an axle of a different type with a thermal or hybrid engine for example. It is also not excluded to use the proposed axle in a vehicle with more than two axles.

[0041] Structure

[0042] With reference to [Fig.l], the axle is organized around an axis, the axle denoted A, generally perpendicular to a longitudinal axis X of the vehicle carried by the axle. On the axle in question, a left wheel W1 and a right wheel W2 are mounted, which are most of the time in contact with the ground but one of which can also sometimes be raised relative to the ground, particularly in off-road conditions with the crossing of obstacles or the crossing of ruts. The example illustrated concerns an axle with non-steered wheels, but the solution presented can also be applied to an axle with steered wheels. Similarly, the suspension of the axle can be of the independent suspension type or not.

[0043] The axle receives driving power from a first motor member M1 and a second motor member M2. Concerning the motor member, it is for example preferably an electric machine, for example a brushless electric motor. Depending on the control logic of the motor poles, the electric machine can be a motor or the electric machine can be a generator in which case it is in an energy recovery mode.

[0044] The axle comprises a first driving wheel 11 (for example the one located on the left) meshing with an output pinion of the first driving member M1 and a second driving wheel 12 (for example the one located on the right) meshing with an output pinion of the second driving member M2. In [Fig.l], the teeth 14, 16 respectively on the motor side and the driving wheel side are shown.

[0045] In the illustrated example, the first driving wheel 11 with its driving member M1 is symmetrical to the second driving wheel 12 with its driving member M2 with respect to a median axis of the vehicle denoted PX. Depending on the possible integration of the axle in the vehicle, of course, the configuration could be asymmetrical.

[0046] The axle comprises a main axle shaft 10 which is rotatably mounted about the axle axis A and generally interposed between the left and right wheel shafts. The main axle shaft 10 comprises a cylindrical axial portion extending essentially along the axis, the latter may be supplemented by elements auxiliaries which are described later.

[0047] The axle comprises at least two planet gears (references 21 and 22). Each planet gear is permanently engaged by teeth with both the first driving wheel 11 and the second driving wheel 12. In the example illustrated, the teeth 15 are oriented at 45° relative to the axle axis A. The configuration thus defined resembles a conical or spherical axle differential except that the assembly is reversed. In fact, the output of the system is here the planet carrier, unlike a conventional axle differential.

[0048] The main axle shaft 10 comprises two diametrically opposed radial supports 24, 25. The radial supports 24, 25 are rigidly mounted relative to the axial portion of the main axle shaft 10.

[0049] On each of these radial supports is mounted a satellite pinion. Thus, the main axle shaft 10 forms a satellite carrier function for the two satellite pinions 21, 22.

[0050] A planar differential type assembly could be used instead of a conical differential type assembly. The technical characteristic can thus be generalized by indicating that each of the two satellite pinions 21, 22 participates in a permanent toothed engagement with the first driving wheel 11 and with the second driving wheel 12.

[0051] It is noted that the number of satellite gears can be greater than 2.

[0052] The axle comprises a left wheel shaft 31 coupled to the left axle wheel W1 and a right wheel shaft 32 coupled to the right axle wheel W2. In the first embodiment illustrated in Figures 1 to 6, the left wheel shaft 31, respectively right 32, is directly coupled to the left, respectively right, axle wheel. We will see later that a reducer or a gear mechanism can be interposed at this location. But, as already mentioned, there can be at least one cardan joint at the interface with the wheel for a suspension function or for a steering function.

[0053] Furthermore, the axle comprises a first left coupling member 41 capable of selectively engaging, in rotation about the axle axis A, the left wheel shaft 31 with the main axle shaft 10. In the first embodiment, the engagement of the left wheel shaft 31 with the main axle shaft 10 via the first left coupling member 41 is direct, without an intermediary. It will be seen later that the coupling in question can be done via a reducer or a gear train.

[0054] Furthermore and in a similar manner, the axle comprises a first right coupling member 42 capable of selectively engaging, in rotation about the axle axis A, the right wheel shaft 32 with the main axle shaft 10. The coupling can be made directly as illustrated in the first embodiment or via a reducer or a train of gears as discussed later.

[0055] The first coupling member (left 41 or right 42) is in the example illustrated a hydraulic clutch. Opposite discs are pressed against each other by a controlled hydraulic pressure. There may be a pair of discs (single-disc clutch) or several pairs of discs in mutual interaction (multi-disc clutch). Such a hydraulic clutch may be controlled by a regulated hydraulic pressure to allow a certain slip between the 2 respective rotating parts.

[0056] In an alternative embodiment, the first coupling member (left or right) may be a mechanical dog clutch system, for example with an axially movable grooved sleeve, known by the English term 'dog clutch'.

[0057] In addition, the axle comprises a second left coupling member 51 capable of selectively engaging, in rotation about the axle axis A, the left wheel shaft 31 with the first driving wheel 11. The coupling can be made directly or via a reducer or a gear train.

[0058] In addition, the axle comprises a second right coupling member 52 capable of selectively engaging, in rotation about the axle axis A, the right wheel shaft 32 with the second driving wheel 12. The coupling can be made directly or via a reducer or a gear train.

[0059] The second coupling member (left 51 or right 52) ​​is in the example illustrated a hydraulic clutch, for example a single-disc clutch or a multi-disc clutch, as already mentioned above. Here too, the hydraulic clutch can be controlled by a regulated hydraulic pressure to allow a certain sliding between the 2 respective rotating parts.

[0060] In an alternative embodiment, the second coupling member (left or right) may be a mechanical dog clutch system, for example with an axially movable grooved sleeve, known by the English term 'dog clutch'.

[0061] The left coupling members 41, 51 are housed in a left clutch housing 34. The right coupling members 42, 52 are housed in a right clutch housing 36.

[0062] Operation

[0063] Figures 2 to 6 illustrate different modes of operation of the proposed transmission device. The parts represented with thick lines are the stressed parts of the system while the parts represented with thin lines are not mobilized.

[0064] The central assembly 35 with the satellite pinions 21, 22 implies that the rotational speed of the main axle shaft 10 is the algebraic half-sum of the rotational speed of the first driving wheel 11 and the rotational speed of the second driving wheel 12. In other words, if we denote V10 the rotational speed of the main shaft of axle 10, VI1 the rotation speed of the first driving wheel 11 and, V12 the rotation speed of the second driving wheel 12, then by construction we have VIO = (V11+V12) / 2. The speed values ​​are signed: we take as a reference by convention a positive rotation speed contributing to moving the vehicle forward, a negative rotation speed value contributing to moving the vehicle backward.

[0065] [Fig.2] illustrates the case of an independent drive control applied respectively to the left wheel and to the right wheel. The torque transmission follows the arrows F1, F2 shown in dot-and-dash lines in [Fig.2].

[0066] The first left coupling member 41 and the first right coupling member 42 are in the inactive state, i.e. clutch open.

[0067] The second left coupling member 51 is in the activated state, that is to say it secures the first driving wheel 11 in rotation with the left wheel shaft 31. Here the configuration corresponds to a closed clutch, without slipping.

[0068] The second right coupling member 52 is in the activated state, that is to say it secures the second driving wheel 12 in rotation with the right wheel shaft 32. Here too the configuration corresponds to a closed clutch, without slipping.

[0069] In cases where the wheel speeds W1, W2 are not identical, the planet gears 21, 22 can rotate freely on themselves, which allows a speed difference between the first driving wheel 11 and the second driving wheel 12. The main axle shaft 10 rotates according to the rotation of the planet gears. The above-mentioned situation corresponds to taking a conventional bend on a road course with the outside wheel traveling more distance. Conversely, in the case where the wheel speeds W1, W2 are identical, the main axle shaft 10 does not rotate (straight line situation).

[0070] In this mode, the electric motors can also work in regenerative mode whether in a downhill driving scenario, or during deceleration or even in the case of active electric braking.

[0071] [Fig. 3] illustrates an operating mode with vectorization of the drive torques applied to the wheels. As in the previous case of [Fig. 2], the second left coupling member 51 is in the activated / closed state and the second right coupling member 52 is in the activated / closed state. But unlike the previous [Fig. 2], the first right coupling member 42 is partially closed, and therefore the main axle shaft 10 is driven from the second drive member via the second right coupling member 52 and the first right coupling member 42.

[0072] A part of the torque generated by the second electric motor M2 is thus directed towards the satellite carrier of the central differential and the satellite pinions 21, 22 transmit this torque towards the left wheel W1 which is added to (or subtracted from) the torque generated by the first electric motor. This is illustrated by a chain-dotted arrow F3 in [Fig.3]. This vectoring mode can also be applied in the event of energy recovery (deceleration or braking).

[0073] It is noted here that the control of the electric motors can follow a torque control logic or a speed control logic. The case where one of the motors is torque controlled and the other motor is speed controlled is notably used in the case of vectoring the transmitted or received torques. The sliding of the first right coupling member 42 can be controlled from a control unit (not shown), for example to contribute to the anti-skid function.

[0074] [Fig.4] illustrates a freewheel operating mode or in other words drag minimization mode. The four coupling members 41, 42, 51, 52 are in the open state, the right and left wheels W1 W2 are in a freewheel configuration. This minimizes the drag introduced by the presence of the axle, in its state without traction. This mode will be favored in situations of medium or high speed ranges (road and highway).

[0075] [Fig.5] illustrates a mode of operation in the event of failure of one of the motor components, here for example motor M2. M2 no longer produces motor or resistive torque.

[0076] The second left coupling member 51 is in the activated / closed state, without sliding.

[0077] The first left coupling member 41 is in the activated state, that is to say it secures the main axle shaft 10 in rotation with the left wheel shaft 31.

[0078] The first right coupling member 42 is in the activated state, i.e. it connects the main axle shaft 10 in rotation with the right wheel shaft 32.

[0079] The path of the torque to drive the right wheel W2 from the first motor Ml is illustrated by an arrow F5 in a chain line in [Fig.5].

[0080] The first right coupling member 42 is controlled to allow a certain slip and to allow a speed difference between the left and right wheels.

[0081] [Fig.6] illustrates the operation, called track or “offroad”.

[0082] The second left coupling member 51 and the second right coupling member 52 are in the inactive state, i.e. clutch open.

[0083] The first left coupling member 41 is in the activated state, that is to say it secures the main axle shaft 10 in rotation with the left wheel shaft 31. Here the configuration corresponds to a closed clutch, without slipping.

[0084] The first right coupling member 42 is in the activated state, that is to say it rotationally secures the main axle shaft 10 with the right wheel shaft 32. Here too the configuration corresponds to a closed clutch, without slipping.

[0085] Thus the axle differential locking function is performed by the closed clutches 41 42.

[0086] In this mode, the wheels of the vehicle do not rotate quickly; in most cases, the speed is very low or even the vehicle is almost static. The rotation speed of the main axle shaft 10 is thus low or even zero.

[0087] It is advantageous to choose rotation speeds for each of the 2 motors sufficiently far from zero speed to avoid heating of the electronic power control circuits of the motors M1, M2.

[0088] We have already seen that V10 = (VI1+V12) / 2. As a reminder, Vil and V12 are signed values, generally opposite in this mode.

[0089] In off-road mode, travel is at very low speed in difficult terrain with obstacle and / or rut crossings, or movement on slippery or muddy terrain. The speed of the main axle shaft V 10 is very low.

[0090] Advantageously, the first motor M1 is driven in a first direction of rotation and the second motor M2 in the opposite direction of rotation. For example, choose Vil between 100 rpm and 500 rpm and V12 = - VI1 in signed values.

[0091] We thus obtain the characteristic that for a speed of the main axle shaft 10 lower than a first predefined threshold SV1, the rotation speed VI1 of the first driving wheel 11 and the rotation speed V12 of the second driving wheel 12 are, in absolute value, each greater than a second predefined threshold SV2, with SV2>SV1.

[0092] For example, one can choose 110 rpm for SV and 30 rpm for SV2.

[0093] According to a second embodiment, illustrated in [Fig.7], the device of The proposed transmission can be coupled via a longitudinal axis shaft of the vehicle to another axle or bridge of the vehicle.

[0094] More precisely, the radial supports 24, 25 rigidly secured to the main axle shaft 10 also carry a toothed crown 90 provided with a 45° bevel gear 91. This toothed crown 90 is engaged with a bevel gear 92 mounted on a longitudinal shaft 94 having an axis of rotation parallel or coinciding with the longitudinal axis of the vehicle X. In addition, a clutch 96 is provided for selectively coupling or uncoupling the two axles together.

[0095] The remainder of the elements of the second embodiment not described in particular are considered to be identical or similar to the elements of the first embodiment.

[0096] According to a third embodiment, illustrated in [Fig.8], the proposed transmission device comprises a planetary gear train 8 interposed between the first and second coupling members (41,51) and the wheel shaft. Only the left part of the axle has been shown in [Fig.8]. [Fig.9] illustrates in more detail the planetary gear train 8 which is illustrated in [Fig.8].

[0097] In this configuration, a first intermediate shaft 61 and a second intermediate shaft 71 are provided. The first intermediate shaft 61 is connected on the side central to the first left coupling member 41, and carries on the wheel side the sun pinion 62 of the planetary gear train 8.

[0098] The second intermediate shaft 71 is connected on the central side to the second left coupling member 51, and forms on the wheel side a satellite carrier function for two sets of satellite pinions 74, 76 of the planetary gear train 8.

[0099] In the double-satellite planetary gear set, the second intermediate shaft is rigid in rotation with a planet carrier part which forms a bearing 75 for the first planet pinion 74 and a second bearing 77 for a second planet pinion 76. The first planet pinion 74 is permanently engaged by teeth 85, 86 with the second planet pinion 76. The first planet pinion is also permanently engaged with the sun pinion 62 via the teeth 82, 83.

[0100] The wheel shaft 31 is integral with, or carries, an outer crown with radially internal teeth 88. The teeth 87 of the second satellite pinion 76 are engaged, on the outer side, with the aforementioned radially internal teeth 88. Finally, the second satellite pinion 76 is engaged on the inner side on a toothed wheel 80 here fixed relative to the axle housing, by mutual engagement of the teeth 84, 86.

[0101] The double-set planetary gear train 8 illustrated here is known in practice as a "Ravigneaux" train. In the third embodiment, it functions as a reduction gear.

[0102] The remaining elements of the third embodiment not described in particular are considered identical or similar to the elements of the first embodiment.

[0103] According to a fourth embodiment, illustrated in [Fig. 10], the transmission device includes the motors in a mechanical integration logic.

[0104] Only the left part of the axle is shown. The engine M1 is arranged between on the one hand the central differential, in particular the driving wheel 11, and on the other hand the first and second left coupling members 41, 51.

[0105] The coils 26 of the motor are arranged circumferentially with an axis coincident with the axle axis A.

[0106] The rotor of the motor is rigid in rotation with a tubular shaft 58 which passes through the motor ML. The tubular shaft 58 is connected on the central side with the driving wheel 11, and is connected on the opposite side to the second coupling member 51.

[0107] Furthermore, the kinematic system can be supplemented by two auxiliary clutches which provide a gearbox function. A first auxiliary clutch 47 (for example band brake) makes it possible to immobilize the rotation of the second intermediate shaft 71. A second auxiliary clutch 46 (for example band brake) immobilizes or releases the rotation of the wheel carrying the teeth 84.

[0108] The “Ravigneaux” train operates in this third embodiment, as a ratio selector, e.g. reducer or multiplier.

[0109] A control unit is provided for controlling the two electric motors as well as the state of the coupling members or clutches. The power control of the motors can be integrated in the control unit or can be located respectively on each of the motors M1, M2.

Claims

1. Claims Transmission device for a vehicle axle having an axle shaft (A), the device comprising: • a first driving wheel (11) intended to be driven by a first motor member (Ml), • a second driving wheel (12) intended to be driven by a second motor member (M2), • a left wheel shaft (31) intended to be coupled to a left axle wheel (Wl), • a right wheel shaft (32) intended to be coupled to a right axle wheel (W2), • at least two satellite pinions (21,22), • a second left coupling member (51) capable of selectively engaging in rotation the left wheel shaft (31) with the first driving wheel (11), directly or via a reducer, • a second right coupling member (52) capable of selectively engaging in rotation the right wheel shaft (32) with the second driving wheel (12), directly or via a reducer, the device being configured in that it comprises: • a main axle shaft (10) mounted to rotate around the axle axis (A) and interposed between the left and right wheel shafts (31, 32), • a first left coupling member (41) capable of selectively engaging in rotation the left wheel shaft (31) with the main axle shaft (10), directly or via a reducer, • a first right coupling member (42) capable of selectively engaging in rotation the right wheel shaft (32) with the main axle shaft (10), directly or via a reducer, • / and where the main axle shaft (10) forms a satellite carrier function for the at least two satellite pinions (21, 22), each of the at least two satellite pinions (21, 22) providing permanent toothed engagement with the first driving wheel (11) and with the second driving wheel (12),

2. Device according to claim 1, wherein the first left coupling member (41) and / or the first right coupling member (42) is a hydraulic clutch.

3. Device according to any one of claims 1 to 2, wherein the second left coupling member (51) and / or the second right coupling member (52) is a hydraulic clutch.

4. A device according to any one of claims 1 to 3, wherein the rotational speed of the main axle shaft (10) is the algebraic half-sum of the rotational speed of the first drive wheel (11) and the rotational speed of the second drive wheel (12).

5. Device according to claim 4, wherein for a track / offroad mode, with the first left and right coupling members (41, 42) engaged, and with a speed of the main axle shaft (10) lower than a first predefined threshold (SV1), the rotational speed (VI1) of the first driving wheel (11) and the rotational speed (V12) of the second driving wheel (12) are each greater than a second predefined threshold SV2, and SV2>SV1.

6. A device according to any one of claims 1 to 5, wherein when the four coupling members are in the uncoupled state, the right and left wheels are in a freewheel configuration.

7. Device according to any one of claims 1 to 6, wherein the first driving wheel (11) and the second driving wheel (12) are rotatably mounted about the axle axis (A) and the first driving wheel (11) and the second driving wheel (12) are arranged on either side, symmetrically with respect to an axle median plane (PX).

8. A device according to any one of claims 1 to 7, further including the first drive member (Ml) and the second drive member (M2), the first and second drive members (Ml, M2) being electric motors.

9. Device according to claim 8, in which each of the first and second motor members (M1, M2) have a rotor having an axis coincident with the axle axis (A).

10. Device according to any one of claims 1 to 9, wherein the main axle shaft (10) is rigid in rotation with an auxiliary toothed wheel (90) which can be selectively driven by a longitudinal shaft (94) of the vehicle from another axle or from an auxiliary, electric or thermal motor unit.

Images