Differential module

The differential module simplifies and compacts the structure of vehicle transmission systems by using a sliding sleeve with form cooperation links and assist springs to manage wheel shaft engagement, addressing inefficiencies and mechanical losses.

FR3164150A1Pending Publication Date: 2026-01-09VALEO EMBRAYAGES SAS
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Patent Information

Application Number
FR2024007452
Authority / Receiving Office
FR · FR
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-07-08
Publication Date
2026-01-09

AI Technical Summary

Technical Problem

Existing differential modules in vehicle transmission systems are complex and lack compactness, with coupling mechanisms that do not efficiently address the need for selective wheel drive shaft engagement and disengagement, leading to inefficiencies and mechanical losses.

Method used

A differential module with a sliding sleeve that axially moves through a planetary gear, utilizing form cooperation links and assist springs to achieve four distinct positions – connected, locked, disconnected, and parked – for efficient torque transmission and wheel shaft management, simplifying the structure and reducing mechanical losses.

Benefits of technology

The differential module enhances efficiency by allowing seamless transitions between operating modes, reducing mechanical losses, and ensuring optimal traction and immobilization, while maintaining a compact design.

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Abstract

The invention relates to a differential module (2) having a first axis of rotation (X1) and comprising: a planet carrier (9); a planet gear (11) pivotally mounted on the planet carrier (9); first and second planetary gears (12, 13) pivoting about the first axis of rotation (X1); first and second wheel drive shafts (3, 4), the first wheel drive shaft (3) being rotationally linked to the first planetary gear (12); and a sliding sleeve (8) movable between two axial positions; a form-cooperative connection being provided between the sliding sleeve and the first wheel drive shaft so as to selectively couple the first wheel drive shaft with the second wheel drive shaft in a locked position of the differential module. (Short figure: 3)
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Description

Title of the invention: Differential module technical field

[0001] The present invention relates to a differential module of a transmission system for a vehicle. Technological background

[0002] Transmission systems incorporating a differential module are designed to transmit and distribute torque from an engine to two wheel drive shafts of a vehicle axle. The differential module comprises an input element intended to be driven by an engine and an output element intended to drive one or both of the two wheel drive shafts of the vehicle axle. In order to selectively make the vehicle wheels free or driven, the differential module may include coupling means capable of selectively coupling the input element to the output element and / or selectively coupling the output element to one of the two wheel drive shafts.

[0003] Document EP0241382 describes in particular such a differential module where coupling means include a sliding piece constantly fixed in rotation to one of the two wheel drive shafts, the sliding piece occupying three positions: a first position where the sliding piece is coupled to a shaft section fixed to an output element of the differential module, a second position where the sliding piece is decoupled from the shaft section and a third position where the sliding piece is fixed in rotation to an input element of the differential module.

[0004] The invention aims to improve this type of device, in particular by simplifying and making the structure of the coupling means more compact and by providing additional functionalities. Summary

[0005] In all that follows, ordinal numeral adjectives are used to differentiate features. They do not define the position of a feature. Therefore, for example, a third feature of a product does not mean that the product has a first and / or a second feature.

[0006] The invention relates to a differential module for a vehicle transmission system, the differential module having a first axis of rotation and comprising: • a satellite carrier capable of receiving a torque supplied, directly or indirectly, by a traction motor; • at least one satellite pinion mounted pivoting on the satellite carrier; • a first and a second planetary gear pivoting around the first axis of rotation; • a first and a second wheel drive shaft, the first wheel drive shaft being rotationally linked to the first planetary gear; and • a portable player that moves axially along the first axis of rotation; a second connection by cooperation of forms being arranged between the sliding gear and the second wheel drive shaft so as to ensure coupling of the second planetary gear with the second wheel drive shaft in a first axial position of the sliding gear, called the locked position, and in a second axial position of the sliding gear, called the connected position; and

[0007] a fourth link by cooperation of shapes being arranged between the slider and the first wheel drive shaft so as to selectively ensure a coupling of the first wheel drive shaft with the second wheel drive shaft in the blocked position, and to selectively ensure the decoupling of the first wheel drive shaft with the second wheel drive shaft in the connected position.

[0008] In the connected position, it is possible to transmit torque between the traction motor and the first and second wheel drive shafts, by acting as a differential that allows different rotational speeds for the two wheel drive shafts. This operating mode is used particularly when the vehicle is turning.

[0009] In the locked position, the relative movement between the first and second planetary gears is blocked, and the first and second wheel drive shafts are forced to rotate at the same speed as the planet carrier. This operating mode is used, in particular, to prevent the risk of loss of traction or the vehicle becoming stuck when the two opposite wheels of the vehicle encounter a difference in friction on the road.

[0010] For the purposes of the present invention: • “axial” means “parallel to the first axis of rotation”; • “Radial” means “along an axis belonging to a plane orthogonal to the first axis of rotation and cutting this first axis of rotation"; • the terms “external” and “internal” are used to define the relative position of a component or a portion of a component with respect to the axis of rotation for which it is concentric, a component close to said axis is thus described as internal as opposed to an external component located radially on the periphery; • Two parts are said to be "rotationally linked" or "coupled" when they are assembled in such a way that they do not rotate relative to each other. Otherwise That said, it is a rotationally rigid joint, possibly with a small amount of play such as spline play. This rotationally rigid joint can be made directly from the first part to the second part or via one or more intermediate parts.

[0011] According to a further feature of the invention, the fourth form cooperation link is configured to selectively ensure coupling of the second planetary pinion with the first wheel drive shaft, the fourth form cooperation link comprising a fourth toothing arranged on the sliding part, the fourth toothing preferably being of the dog type oriented in axial projection.

[0012] Each form cooperation link of the present invention comprises a first form arranged on the player and a second complementary form arranged on another component so that said component cooperates in rotation with the player by said form cooperation link.

[0013] According to an additional feature of the invention, a first form cooperation link is provided between the slider and the second planetary pinion, the first form cooperation link being configured so that the slider is permanently linked in rotation to the second planetary pinion and so that the slider slides axially relative to the second planetary pinion.

[0014] In the differential module architecture according to this latter characteristic, the sliding sleeve cooperates directly and continuously with the second planetary gear, unlike a common prior art architecture where a shaft section is required to connect the sliding sleeve to the second planetary gear. This architecture is therefore simpler and more economical.

[0015] Furthermore, in this architecture, it is possible to slide the sliding sleeve axially through the second planetary gear to allow direct access to the first wheel drive shaft and thus achieve coupling in the locked position in a simple and compact manner. The sliding sleeve can be coupled here either between the sliding sleeve and the first wheel drive shaft or between the sliding sleeve and the first planetary gear.

[0016] According to an additional feature of the invention, the first joint by cooperation of forms comprises a male groove provided on the sliding part and a female groove provided on the second planetary pinion.

[0017] According to an additional feature of the invention, a surface of the satellite carrier ensures radial centering of a surface of the portable player.

[0018] These last two characteristics ensure sufficient axial guidance of the slider throughout its entire movement.

[0019] According to an additional feature of the invention, a radial and axial guiding means is provided between the slider and the satellite carrier, the guiding means comprising a bearing or a sliding coating or a bearing.

[0020] This last characteristic makes it possible to ensure sufficient axial guidance of the slider over the entirety of its movement, while limiting friction and therefore the forces provided by the actuator to move the slider into the four positions.

[0021] According to an additional feature of the invention, the second form cooperation link further selectively ensures the decoupling of the second wheel drive shaft in a third axial position of the slider, called the disconnected position.

[0022] In the disconnected position, the torque transmission between the traction motor and the first and second wheel drive shafts is disconnected. This operating mode is used particularly during vehicle operation phases where drive to the wheels of an axle is not required. This improves the overall efficiency of the vehicle's driveline by eliminating mechanical losses associated with the rotation of various unused components.

[0023] According to a further feature of the invention, the second form cooperation link comprises a second toothing arranged in a cavity of the slider receiving a portion of the second wheel drive shaft, the second toothing preferably being of the internal type oriented radially.

[0024] According to an additional feature of the invention, a third form cooperation link is configured to be arranged between the slider and a fixed frame, in particular a housing, so as to selectively ensure coupling of the second planetary pinion with the fixed frame in a fourth axial position of the slider called parking position, the third form cooperation link comprising a third set of teeth arranged on the slider, the third set of teeth preferably being of the dog type oriented in axial projection.

[0025] In the parking position, the movement of the second wheel drive shaft is completely blocked. This operating mode is used, in particular, to ensure that the vehicle remains immobilized when parked.

[0026] Dog-type teeth are a simple and robustly designed coupling means which allows for quick coupling / decoupling of the slider.

[0027] According to an additional feature of the invention, all the aforementioned dog-type teeth can be "anti-release" type teeth.

[0028] In a manner known from the prior art, anti-release dog-type teeth have undercuts and undercuts with angles chosen to ensure that the teeth cannot disengage spontaneously while transmitting torque, thus preventing untimely disconnection.

[0029] In general, all the aforementioned teeth can be in other embodiments of the invention of the axial or radial type, without angle, or with an angle favoring the engagement of the teeth while they transmit a torque, or on the contrary with an angle favoring the disengagement of the teeth while they transmit a torque.

[0030] According to one aspect of the invention, the four axial positions of the slider follow one another in a first determined sequence as the slider moves away in a direction opposite to the first planetary pinion, the locked position being the closest to the first planetary pinion, the connected position then succeeding the locked position, the disconnected position then succeeding the connected position and the parking position then succeeding the disconnected position.

[0031] This first determined sequence makes the transition from one position to the other more efficient and safer. Indeed, the transition to the parking position is advantageously carried out from the disconnected position to limit the relative speed between the moving part and the fixed frame, and thus reduce shocks and over-torque during the coupling phase.

[0032] In addition, since the connected position corresponds to the most frequently used operating mode on a vehicle, it is advantageous to place this connected position between the locked position and the disconnected position in order to limit the distance and travel time of the player to reach one or the other of these last two positions.

[0033] According to another aspect of the invention, the four axial positions of the slider follow one another in a second determined sequence as the slider moves away in a direction opposite to the first planetary pinion, the locked position being the closest to the first planetary pinion, the disconnected position then succeeding the locked position, the connected position then succeeding the disconnected position and the parking position then succeeding the connected position.

[0034] According to an additional feature of the invention, a number of active positions between two and four is chosen from among the four positions of the slider so that only the active positions thus chosen are used during the operation of the differential module on the vehicle, the number of positions chosen being predetermined according to the needs of each vehicle application.

[0035] Indeed, the arrangement of the four aforementioned positions also allows the differential module according to the invention to be used as such even if, depending on the needs of a vehicle application, the locking position and / or the parking position are not necessary.

[0036] According to a further feature of the invention, the slider is arranged to be moved by an actuator, the slider comprising in particular an annular groove cooperating with a fork linked to the actuator.

[0037] The invention makes it possible to move the portable player into the four positions mentioned above with a single actuator.

[0038] According to an additional feature of the invention, a first assist spring is arranged to exert axial force on the slider so as to promote the transition to the connected position and / or its transition to the locked position.

[0039] According to an additional feature of the invention, a second assist spring is arranged to exert axial force on the slider so as to facilitate the transition to the parking position.

[0040] For the two preceding features, "facilitating the transition" means that, during the movement of the sliding sleeve from one position to another, when the coupled gear teeth happen to be in relative angular misalignment such that their engagement is not immediately possible, the assist spring compresses and exerts a force on the sliding sleeve. As soon as the relative rotation of the teeth places them in a position of mutual engagement, the spring, by relaxing, helps the sliding sleeve to position itself in its new position. The spring thus accelerates the mutual engagement of the coupled gear teeth, which improves the dynamics of the differential module. Indeed, the spring can move the connecting sliding sleeve more quickly than an actuator alone would because the inertia of the spring is lower.

[0041] According to a first aspect of the invention: • the portable player has two parts that are axially movable relative to each other; • the first part being configured to cooperate with the actuator; • the second part being configured to selectively ensure coupling in the locked, connected, disconnected, and parked positions; and • the first and second assist springs being interposed axially between the first and second part.

[0042] According to an additional feature of the invention, the first part of the player is radially centered on the second part of the player.

[0043] According to an additional feature of the invention, the first part of the slider is rotationally linked to the second part of the slider, in particular by teeth.

[0044] According to a further feature of the invention, the first assist spring is arranged axially on a first side of the first part of the slider and the second assist spring is arranged axially on a second side of the first part of the player, the first side being closer axially to the first planetary gear than the second side.

[0045] According to another aspect of the invention, the first assist spring and the second assist spring are interposed axially between the slider and a fork linked to the actuator.

[0046] According to an additional feature of the invention, the first assist spring and / or the second assist spring are of the helical spring type or wave washer or Belleville type frustoconical washer or elastomer material spring.

[0047] The invention further relates to a transmission system comprising the differential module according to the invention, a fixed frame in particular a housing, a set of gears configured to make the differential module cooperate in rotation with a traction motor, and an actuator configured to move the slider.

[0048] The differential module according to the invention may have one or more of the characteristics described below, either combined or taken independently of each other: • at least one satellite gear and both planetary gears can be bevel gears; • at least one satellite pinion is mounted pivotally on a cylindrical axis fixed to the satellite carrier; • at least one satellite pinion and the two planetary pinions can be made in the form of cylindrical gears, in particular straight-toothed gears, in particular gears arranged in the form of an epicyclic train; • the differential module may be of the limited slip differential type in which a friction device is arranged to create a torque difference between two wheels connected to the differential module, particularly in connected mode; • at least one satellite pinion and the two planetary pinions can be made in the form of worm gears, the differential module can in particular be of the "Torsen" type; • the number of satellite gears is between one and twelve; • The satellite carrier can be made in the form of a housing comprising a internal cavity in which are housed at least one satellite pinion and the two planetary pinions; • the two planetary gears are supported and guided in rotation by the housing; • the casing can be made in several parts, fixed together by a means of fastening, in particular by welding or by screwing or by riveting; • a toothed wheel is fixed to the satellite carrier, the toothed wheel receiving, via a set of gears, the torque supplied by a traction motor.

[0049] The transmission system according to the invention may have one or more of the characteristics described below, either combined or taken independently of each other: • the fixed frame can be a housing for the transmission system; • The transmission system housing may be designed to accommodate the play gears and the differential module; • the gear set may include cylindrical gears with parallel trains; • the gear set may include at least one epicyclic gear train; • the actuator can be of mechanical, electromechanical, electromagnetic, pneumatic or hydraulic type; • The actuator may include a ball ramp or ball screw system or a selector drum system.

[0050] The invention further relates to a powertrain comprising a traction motor and a torque transmission system as defined above.

[0051] The fixed frame may be a powertrain housing, in particular a traction motor housing. Brief description of the figures

[0052] [Fig-1] Fig. 1 illustrates a schematic cross-sectional view of a powertrain including a differential module according to the invention.

[0053] [Fig.2] The [Fig.2] is a cutaway perspective view of the differential module according to a first embodiment of the invention.

[0054] [Fig.3] The [Fig.3] is a cross-section of the differential module in connected position according to a first embodiment of the invention.

[0055] [Fig.4] The [Fig.4] is a cross-section of the differential module in the locked position according to a first embodiment of the invention.

[0056] [Fig.5] The [Fig.5] is a cross-section of the differential module in the parking position according to a first embodiment of the invention.

[0057] [Fig.6] The [Fig.6] is a cross-section of the differential module in the disconnected position according to a first embodiment of the invention.

[0058] [Fig.7] The [Fig.7] is a cutaway perspective view of the player according to a first embodiment of the invention.

[0059] [Fig-8] The [Fig.8] is a cross-section of the differential module in the locked position according to a second embodiment of the invention. Description of the implementation methods

[0060] In all the figures, identical elements or elements performing the same function are identified by the same reference numerals. The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference numeral relates to the same embodiment or that the features apply only to a single embodiment. Simple features from different embodiments can also be combined or interchanged to provide other embodiments.

[0061] Figure 1 schematically illustrates a powertrain 1 according to an embodiment of the invention. The powertrain 1 comprises a differential module 2 for rotating two wheel drive shafts 3 and 4 of a vehicle axle and configured to distribute torque from a traction motor 5 to the wheel drive shafts 3 and 4, allowing them to rotate at different speeds.

[0062] Such a differential module 2 is, for example, intended for a hybrid vehicle. Thus, the powertrain 1 is, for example, capable of transmitting torque from an electric motor to a rear or front axle of the vehicle, while another powertrain coupled to another engine, such as an internal combustion engine, generates torque and transmits it between this other engine and the wheel drive shafts 3, 4 of the other axle of the vehicle. Another powertrain configuration for a hybrid vehicle may consist of combining an internal combustion engine and an electric motor, both working together to transmit torque to the wheel drive shafts 3, 4 of the same axle. The vehicle may also be fully electric.

[0063] As shown in [Fig. 1], the powertrain 1 comprises a transmission housing 6 in which a traction motor 5, a differential module 2, and a gear set 7 are housed. The structure of the transmission housing 6 may be a single unit or composed of several sub-parts. The traction motor 5 includes, at its output, a shaft rotating about a third axis of rotation X3. The gear set 7 cooperates kinematically in rotation with, on the one hand, the shaft of the traction motor 5 and, on the other hand, with the differential module 2 to form one or more speed reduction ratios.

[0064] In the non-limiting example of [Fig. 1], the gear set 7 comprises a first train of cylindrical gears 701, coaxial with the third axis of rotation X3, and cooperating kinematically in rotation with a second train of gears Cylindrical gears 702, coaxial with a fourth axis of rotation X4 parallel to the third axis of rotation X3, form a first reduction ratio. The second set of cylindrical gears 702 cooperates kinematically in rotation with a toothed wheel 10 fixed to a housing 9 of the differential module 2 to form a second reduction ratio.

[0065] In this example, the traction motor 5 can be an electric or thermal motor. Another electric or thermal motor (not shown) can also be coupled with one of the gears in the gear set 7.

[0066] Figures 1 to 6 illustrate a differential module 2 according to a first embodiment of the invention, the differential module 2 having a first axis of rotation XI and comprising a planet carrier 9 adapted to receive torque supplied directly or indirectly by a traction motor 5, at least one planetary pinion 11 pivotally mounted on the planet carrier 9, a first and a second planetary pinion 12, 13 pivoting about the first axis of rotation XI and meshing with the at least one planetary pinion 11, a first and a second wheel drive shaft 3, 4, the first wheel drive shaft 3 being rotationally linked to the first planetary pinion 12, and a sliding sleeve 8 axially movable about the first axis of rotation XL

[0067] In this embodiment, the planet carrier 9 can be in the form of a housing forming a cavity that accommodates and supports the planet gears 11 and the planetary gears 12, 13. The planet gears 11 and the first and second planetary gears 12, 13 are bevel gears. A cylindrical rod 902 can be fixed to the housing 9, the planet gears 11 being pivotally mounted about the second axis of rotation X2 on said cylindrical rod 902. There can be one to four planet gears 11, choosing four having the advantage of being able to transmit the torque with smaller planet gears. The second axis of rotation X2 is perpendicular to the first axis of rotation XL. The first planetary gear 12 can be mounted and rotationally linked to the wheel drive shaft 3 via a spline 1201. The gear 10 can be fixed to the planet carrier 9 by fixing screws 20.The satellite carrier 9 can be supported by the transmission housing 6 via a first bearing 22, here a ball bearing, and a second bearing 23, here a tapered roller bearing.

[0068] The differential module 2 described above corresponds to a differential design in its most common form. According to another embodiment of the invention not shown, the differential may be of the "flat differential" type where the satellite gears and planetary gears are made in the form of cylindrical gears, in particular spur gears, in particular gears arranged in the form of an epicyclic gear train.

[0069] The sliding sleeve 8 is configured to selectively occupy four axial positions: a connected position illustrated in [Fig. 3], a locked position illustrated in [Fig. 4], a parking position illustrated in [Fig. 5], and a disconnected position illustrated in [Fig. 6]. In the connected position, the sliding sleeve 8 ensures a coupling of the second wheel drive shaft 4 with the second planetary gear 13. In the locked position, the sliding sleeve 8 ensures a coupling of the second wheel drive shaft 4 with the first wheel drive shaft 3. In the parking position, the sliding sleeve 8 ensures a coupling of the second planetary gear 4 with a fixed frame, which in this case is the transmission housing 6. In the disconnected position, the sliding sleeve 8 does not ensure a coupling of the second wheel drive shaft 4.

[0070] The slider 8 is arranged to be moved by an actuator (not shown). The slider 8 may include an annular groove 809 cooperating with a fork (not shown) connected to the actuator. Only one actuator is required to move the slider into the four positions.

[0071] In order to facilitate the axial sliding of the slider 8 over part or all of its movement, an internal surface 901 of the satellite carrier 9 can ensure radial centering of an external surface 810 radially external to the slider 8.

[0072] As illustrated by figures 3 to 6, the four axial positions of the slider 8 can succeed one another in a determined sequence as the slider 8 moves away in a direction opposite to the first planetary pinion 12, the blocked position being the closest to the first planetary pinion 12, the connected position then succeeding the blocked position, the disconnected position then succeeding the connected position and the parking position then succeeding the disconnected position.

[0073] As illustrated in the first embodiment of Figures 2 to 6, the differential module 2 may comprise: • a first link by cooperation of forms by which the slider 8 is permanently linked in rotation to the second planetary pinion 13 and by which the slider 8 slides axially relative to the second planetary pinion 13; • a second link by cooperation of forms by which the slider 8 is coupled to the second wheel drive shaft 4 in connected and locked positions, and by which the slider 8 is decoupled from the second wheel drive shaft 4 in disconnected position; • a third connection by cooperation of forms by which the slider 8 is configured to be coupled to a fixed frame, here the transmission housing 6, in the parking position, and by which the slider 8 is decoupled from the fixed frame in the connected, disconnected and locked positions; and • a fourth link by cooperation of forms by which the slider 8 is coupled to the first wheel drive shaft 3 in the locked position, and by which the slider 8 is decoupled from the first wheel drive shaft 3 in the disconnected, connected and parking positions.

[0074] In the first embodiment of Figures 2 to 7: • the first link by cooperation of forms can include a first externally oriented radially arranged tooth 801 on the sliding 8, the first tooth 801 being here a male spline which cooperates with a female spline 1301 arranged on the second planetary pinion 13; • the second joint by cooperation of forms may include a second internally oriented radial toothing 802, the second toothing 802 being able to be arranged in a cavity 813 of the slider 8 receiving a portion of the second wheel drive shaft 4; • the third link by cooperation of forms may include a third dog-type tooth 803 oriented in projection axially arranged on the sliding 8; • the fourth link by cooperation of forms may include a fourth dog-type tooth 804 oriented in axial projection arranged on the sliding 8.

[0075] In the second embodiment of [Fig. 8], the sliding part 8 may comprise two axially movable parts 811, 812 relative to each other. The first part 811 may be configured to cooperate with the actuator. The second part 812 may be configured to selectively ensure coupling in the locked, connected, disconnected, and parked positions. The first part 811 may be radially centered on the second part 812. The first part 811 may be rotationally linked to the second part 812 by teeth. The first and second assist springs 14, 15 may be axially interposed between the first and second parts 811, 812.The first assist spring 14 can be disposed axially on a first side of the first part 811 and the second assist spring 15 can be disposed axially on a second side of the first part 812, the first side being closer axially to the first planetary pinion 12 than the second side.

[0076] The first and second assist springs 14,15 are here truncated conical washers of the Belleville type.

[0077] It is emphasized that all the features, as they are apparent to a person skilled in the art from the present description, the drawings and the attached claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, can be combined with other features or groups of characteristics disclosed here, insofar as this has not been expressly excluded or technical circumstances render such combinations impossible or meaningless.

[0078] The use of the verb "comporter", "comprendre" and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0079] In the claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Differential module (2) for a vehicle transmission system, the differential module (2) having a first axis of rotation (XI) and comprising: • a planet carrier (9) capable of receiving torque supplied, directly or indirectly, by a traction motor (5); • at least one planetary pinion (11) pivotally mounted on the planet carrier (9); • a first and a second planetary pinion (12, 13) pivoting about the first axis of rotation (XI); • a first and a second wheel drive shaft (3, 4), the first wheel drive shaft (3) being rotationally linked to the first planetary pinion (12); and • a sliding sleeve (8) axially movable about the first axis of rotation (XI);characterized in that: • a second joint by cooperation of forms is arranged between the sliding bearing (8) and the second wheel drive shaft (4) so ​​as to ensure a coupling of the second planetary pinion (13) with the second wheel drive shaft (4) in a first axial position of the sliding bearing (8), called the blocked position and in a second axial position of the sliding bearing (8), called the connected position; and • a fourth joint by cooperation of forms is arranged between the sliding bearing (8) and the first wheel drive shaft (3) so as to selectively ensure a coupling of the first wheel drive shaft (3) with the second wheel drive shaft (4) in the blocked position, and to selectively ensure the decoupling of the first wheel drive shaft (3) with the second wheel drive shaft (4) in the connected position.

2. Differential module according to claim 1, wherein the fourth joint by cooperative forms comprises a fourth tooth (804) fitted on the sliding part (8), the fourth tooth (804) being preferably of the dog type oriented in axial projection.

3. Differential module (2) according to any one of the preceding claims, wherein a first form cooperation link is provided between the slider (8) and the second planetary pinion (13), the first form cooperation link being configured so that the slider (8) is permanently rotationally linked to the second planetary pinion (13) and so that the slider (8) slides axially relative to the second planetary pinion (13).

4. Differential module (2) according to claim 3, wherein the first form cooperation link comprises a male spline (801) provided on the sliding sleeve (8) and a female spline (1301) provided on the second planetary pinion.

5. Differential module (2) according to any one of the preceding claims, wherein a surface (901) of the satellite carrier (9) ensures radial centering of a surface (810) of the slider (8).

6. Differential module (2) according to any one of the preceding claims, wherein the second form-cooperation linkage further selectively decouples the second wheel drive shaft (4) in a third axial position of the slider (8), referred to as the disconnected position.

7. Differential module according to claim 6, wherein the second form cooperation link comprises a second toothing (802) arranged in a cavity (813) of the slider (8) receiving a portion of the second wheel drive shaft (4), the second toothing (802) preferably being of the internal radially oriented type.

8. Differential module (2) according to any one of the preceding claims, wherein a third form-cooperative linkage is configured to be arranged between the sliding sleeve (8) and a fixed frame, in particular a housing (6), so as to selectively ensure coupling of the second planetary pinion (13) with the fixed frame in a fourth axial position of the sliding sleeve (8), referred to as the parking position, the third form-cooperative linkage comprising a third set of teeth (803) arranged on the sliding sleeve. (8), the third tooth (803) being preferably of the dog type oriented in axial projection.

9. Differential module (2) according to any one of the preceding claims in combination with claims 6 and 8, wherein the locked, connected, disconnected and parked positions of the slider (8) follow one another in a determined sequence as the slider (8) moves away in a direction opposite to the first planetary gear (12), the locked position being closest to the first planetary gear (12), the connected position then following the locked position, the disconnected position then following the connected position and the parked position then following the disconnected position.

10. Differential module (2) according to any one of the preceding claims, wherein a first assist spring (14) is arranged to exert axial force on the slider (8) so as to promote the transition to the connected position and / or the locked position.

11. Differential module (2) according to any one of the preceding claims in combination with claim 8, wherein a second assist spring (15) is arranged to exert axial force on the sliding part (8) so as to facilitate the shift into the parking position.

12. Differential module (2) according to any one of the preceding claims, wherein the slider (8) is arranged to be moved by an actuator, the slider (8) comprising in particular an annular groove (809) cooperating with a fork linked to the actuator.

13. Differential module (2) according to claims 10 to 12, wherein: • the sliding part (8) comprises two parts (811, 812) axially movable relative to each other; • the first part (811) being configured to cooperate with the actuator; • the second part (812) being configured to selectively ensure coupling in the locked, connected, disconnected, and parked positions; and

14.

15. • the first and second assist springs (14,15) being interposed axially between the first and second part (811,812). A transmission system comprising the differential module (2) according to any one of the preceding claims, a fixed frame, in particular a housing (6), a gear set (7) configured to rotate the differential module (2) with a traction motor (5), and an actuator configured to move the sliding sleeve (8). A powertrain (1) comprising a traction motor (5) and a torque transmission system according to claim 14.

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