阅读说明：本技术 用于车辆的差速器单元的组件 (Assembly of differential gear unit for vehicle ) 是由 托马斯·巴里约 塞尔日·瓦南蒂 于 2018-04-06 设计创作，主要内容包括：本发明涉及一种用于车辆的差速器单元(10)的组件,该组件包括：-差速器壳体(24a),其具有纵向轴线(23)；-差速器侧齿轮(18),其构造成连接到驱动轴(11),该驱动轴(11)能够连接到车辆的车轮,该差速器侧齿轮位于差速器壳体的内部并且以能够相对于差速器壳体围绕纵向轴线旋转的方式被安装；-锁止系统(100),用于锁止差速器单元的操作,包括：锁止构件(50),其能够在释放位置和锁止位置之间移动；和致动系统(60),用于使锁止构件(50)在所述释放位置和所述锁止位置之间移动；其中,锁止构件(50)位于差速器壳体(24a)的内部,并且被构造成将差速器壳体(24a)和差速器侧齿轮(18)可旋转地固定。(The invention relates to an assembly of a differential gear unit (10) for a vehicle, comprising: -a differential housing (24a) having a longitudinal axis (23); -a differential side gear (18) configured to be connected to a drive shaft (11), the drive shaft (11) being connectable to a wheel of a vehicle, the differential side gear being located inside the differential housing and mounted in a manner rotatable about a longitudinal axis relative to the differential housing; -a locking system (100) for locking the operation of the differential unit, comprising: a lock member (50) movable between a release position and a lock position; and an actuation system (60) for moving the locking member (50) between the release position and the locking position; wherein the locking member (50) is located inside the differential case (24a) and is configured to rotatably fix the differential case (24a) and the differential side gears (18).)

1. An assembly (110) for a differential unit (10) of a vehicle (1), comprising:

-a differential housing (24a, 24b), said differential housing (24a, 24b) having a longitudinal axis (23);

-differential side gears (18), said differential side gears (18) being configured to be connected to a drive shaft (11), said drive shaft (11) being connectable to a wheel (8) of a vehicle (1), said differential side gears (18) being located inside said differential housing (24a), and said differential side gears (18) being mounted in a manner rotatable relative to said differential housing (24a) about said longitudinal axis (23);

-a locking system (100), said locking system (100) being for locking operation of said differential gear unit, said locking system (100) comprising: a locking member (50), the locking member (50) being movable between a release position and a locking position; and an actuation system (60), the actuation system (60) for moving the locking member (50) between the release position and the locking position;

characterized in that the locking member (50) is located inside the differential case (24a), and the locking member (50) is configured to rotatably fix the differential case (24a) and the differential side gear (18).

2. The assembly according to claim 1, characterized in that said actuation system (60) comprises:

-a connecting device (70), said connecting device (70) being connected to said locking member (50) in a rotationally fixed and axially fixed manner;

-an actuating device (65), said actuating device (65) being capable of moving said locking member (50) relative to said differential case (24a) between said release position and said locking position via said connecting device (70).

3. The assembly according to claim 2, wherein said actuating means (65) is located outside of said differential case (24a), and wherein said connecting means (70) comprises:

-an outer portion (80), said outer portion (80) being mounted on said differential case (24a) and outside said differential case (24a), wherein said outer portion (80) is rotatably fixed to said differential case (24a) and said outer portion (80) is movable relative to said differential case (24a) along said longitudinal axis (23) so as to allow moving said locking member (50) between said released position and said locked position;

-at least one through-going portion (71), said at least one through-going portion (71) extending through a differential case peripheral wall (40) for fixedly connecting, in use, said outer portion (80) of said connection device and said locking member (50).

4. The assembly according to any one of claims 1 to 3, characterized in that the locking member (50) is rotatably fixed to the differential case (24a) and the locking member (50) is movable relative to the differential case (24a) along the longitudinal axis (23) between:

-the locking position in which the locking member (50) is engaged with the differential side gear (18) such that the locking member (50) and the differential side gear (18) are rotationally fixed to each other;

-and the release position, in which the locking member (50) is spaced apart from the differential side gear (18).

5. An assembly according to any one of claims 1 to 4, characterized in that the locking member (50) comprises at least one protrusion or recessed relief configured to cooperate, in the locking position, with at least one corresponding recess or protruding relief provided on the differential side gear (18), preferably in the form of a plurality of teeth (56) extending from the periphery of the locking member (50), wherein the locking member (50) is annular and the plurality of teeth (56) is configured to engage with a set of teeth (79) arranged on the differential side gear (18).

6. An assembly according to any one of claims 1 to 5, characterized in that the inner face (41) of the differential case (24a) is provided with at least one protrusion or concave relief and the outer face (54) of the locking member (50) is provided with at least one corresponding recess or convex relief, the inner face (41) of the differential case (24a) and the outer face (54) of the locking member (50) preferably being provided with corresponding longitudinally extending splines (43, 55), the corresponding longitudinally extending splines (43, 55) allowing relative longitudinal sliding movement between the locking member (50) and the differential case (24a) and preventing relative rotational movement between the locking member (50) and the differential case (24a) about the longitudinal axis (23).

7. Assembly according to any one of claims 1 to 6, when depending on claim 3, characterized in that the or each through portion (71) of the connection device (70) is engaged in a through opening (48), the through opening (48) being provided in the peripheral wall (40) of the differential housing (24a), the through portion (71) being axially slidable in the through opening (48), the through opening (48) preferably being elongated in the longitudinal direction, and the through portion (71) being rotatably fixed relative to the differential housing (24 a).

8. Assembly according to claim 7, characterized in that the locking member (50) comprises at least one reception of the or each through portion (71) of the connecting device (70), preferably in the form of a through aperture (57) provided in a peripheral wall (51) of the locking member (50).

9. An assembly according to claim 8, characterised in that the or each through aperture (57) is circumferentially elongate.

10. Assembly according to any one of claims 1 to 9, when depending on claim 3, characterized in that said outer portion (80) of said connection means (70) comprises an inner face (81), said inner face (81) being provided with at least one relief or concave relief, and wherein said outer face (42) of said differential case (24a) is provided with at least one corresponding concave or convex relief, preferably in the form of: at least two protrusions (84), said at least two protrusions (84) being circumferentially spaced relative to each other and said at least two protrusions (84) protruding from said inner face (81) of said outer part (80) of said connection device; and at least two axially extending cavities (44), said at least two cavities (44) being circumferentially spaced relative to each other and said at least two cavities (44) being arranged on said outer face (42) of said differential case so as to allow relative longitudinal sliding movement between said differential case (24a) and said outer portion (80) of said connection device (70) and prevent relative rotational movement between said differential case (24a) and said outer portion (80) of said connection device (70) about said longitudinal axis (23).

11. An assembly according to any one of claims 1 to 10, characterised in that the outer portion (80) of the connection device (70) comprises at least one receptacle of the or each through portion (71) of the connection device (70), preferably in the form of a hole or an internal annular groove (85).

12. Assembly according to any one of claims 1 to 9, characterized in that the outer portion (80) of the connection means (70) comprises an outer face (82), the outer face (82) being provided with an outer annular groove (86) or an outer annular ridge for receiving a portion (68) of the actuation means (65).

13. Assembly according to claim 12, wherein the actuation means (65) and the outer portion (80) of the connection means (70) are free to rotate with respect to each other about the longitudinal axis (23), the actuation means (65) comprising: at least one finger (68), said at least one finger (68) being engaged in said outer annular groove (86) of said outer portion (80) of said connection device; or a hollow for receiving the outer annular ridge of the outer part (80) of the connection device.

14. Assembly according to any one of claims 1 to 13, characterized in that said at least one through portion of said connection device (70) comprises at least two pins (71), preferably four pins (71), more preferably eight pins (71), extending radially, said pins (71) being regularly angularly spaced.

15. An assembly according to any one of claims 1 to 14, further comprising a support member (90), the support member (90) being configured to be axially retained between the differential side gear (18) and an inner collar (28) of the differential housing (24a), and the support member (90) further forming an internal abutment for preventing radially inward movement of the or each through portion (71) of the connection means (70).

16. A differential gear unit (10) of a vehicle (1), the differential gear unit (10) comprising a differential carrier case (20), and the following are mounted in the differential carrier case (20):

-an assembly (110) according to any one of claims 1 to 15;

-a crown wheel (22), the crown wheel (22) having a longitudinal axis (23), the crown wheel (22) being arranged to be driven in rotation about the longitudinal axis (23) by an input shaft (3);

-a differential (15), said differential (15) being arranged substantially inside said crown wheel (22), and said differential (15) comprising: a differential-side pinion (16), the differential-side pinion (16) rotating relative to a spider (17) attached to the crown wheel (22); and two differential side gears (18), the two differential side gears (18) each being connected to at least one differential side pinion and to a drive shaft (11), the drive shaft (11) being connectable to a wheel (8) of a vehicle (1) outside the differential carrier housing (20);

-a differential case arrangement (24), said differential case arrangement (24) containing said differential (15) and a portion of said drive shaft (11), said differential case arrangement (24) comprising two differential cases (24a, 24b), said two differential cases (24a, 24b) being fixed to said crown wheel (22) on both sides of said crown wheel (22), said differential cases (24a, 24b) having the same longitudinal axis as said crown wheel;

wherein a differential case (24a) and the differential side gears (18) located inside the differential case (24a) are part of the assembly (110).

17. A differential gear unit as claimed in claim 16, characterized in that the actuating means (65) is mounted on the differential carrier housing (20) in a rotationally fixed manner.

18. A differential gear unit as claimed in claim 16 or 17, characterized in that the locking system (100) is located inside the differential carrier housing (20) in a region substantially facing one differential housing (24a) in a direction orthogonal to the longitudinal axis (23).

19. A differential gear unit according to any one of claims 16 to 18, characterised in that the locking member (50) is annular and the locking member (50) is preferably arranged around one drive shaft (11).

20. A differential gear unit according to any one of claims 16 to 19, characterised in that the differential gear unit further comprises support means (30) on both sides of the crown wheel (22), the support means (30) being attached to the differential carrier housing (20), and the support means (30) comprising an annular portion in which are received: a portion of a drive shaft (11) inside said differential case (24 a); and a bearing (27) surrounding the differential case (24a), the locking member (50) being located between the differential side gear (18) and the corresponding bearing (27) according to a projection along the longitudinal axis (23).

21. A driven wheel system (6) for a vehicle (1), the driven wheel system (6) comprising: at least one left wheel (8) and one right wheel (8), each wheel (8) being connected to a differential unit (10) according to any one of claims 16 to 20 by a drive shaft (11); at least one joint (11 a); a lower arm (14b), the lower arm (14b) being hinged at both ends; and preferably an upper arm (14a), said upper arm (14a) being hinged at both ends.

22. A driven wheel system (6) for a vehicle (1), the driven wheel system forming an axle and comprising:

-a differential gear unit (10) according to any one of claims 16 to 20;

-an axle housing (7), the axle housing (7) constituting a second housing part (20b), the second housing part (20b) being designed to be assembled to a first housing part (20a) for forming the differential carrier housing (20), and the second housing part (20b) at least partially containing the drive shaft (11);

-at least one wheel (8), said at least one wheel (8) being connected to one end of each drive shaft (11).

23. A vehicle (1), the vehicle (1) comprising at least one driven wheel system (6) according to claim 21 or 22.

Technical Field

The invention relates to an assembly of a differential gear unit for a vehicle. The invention also relates to a differential unit comprising such an assembly, to a driven wheel system comprising such a differential unit, and to a vehicle comprising such a driven wheel system.

Background

Vehicles such as trucks are typically equipped with one or more differential units on their driven axles.

The differential unit generally comprises a differential carrier housing containing the differential mechanism, namely: a crown wheel driven by a pinion fixed to the input shaft; a differential disposed inside the crown wheel and including a pinion and a gear; and a differential housing arrangement containing a differential and a portion of a drive shaft connected to a wheel of the vehicle. The differential housing arrangement may typically be made of two differential housings, each secured to a crown wheel on both sides of the crown wheel, whereby the differential housings are mounted in a differential carrier housing.

The differential allows the corresponding left and right wheels to have different speeds when turning/steering. The maximum torque transmitted through the mechanical differential is limited by the lowest wheel adhesion. Thus, if the wheel is slipping (typically on a low grip surface such as mud, sand, snow, etc.), torque is not transferred to the second wheel and the truck may become stuck.

To avoid this, the differential unit may be equipped with a locking system that enables locking of the operation of the differential unit and transmission of torque to the wheels still in grip, allowing the truck to move.

However, conventional differential gear units can be rather bulky, which is of course disadvantageous, since the space available in a vehicle is often limited.

More specifically, such locking systems are typically located at one end region of the differential unit, depending on the lateral direction of the vehicle, and are configured to rotationally fix the drive shaft and the differential case. This may cause problems because the lateral width of the vehicle (in particular a truck) is limited to the maximum value given by the legislative requirements. In particular, a vehicle having an independent wheel suspension configuration needs to be increased in length in the lateral direction of the vehicle. This means that conventional locking systems cannot be implemented on trucks with independent wheel suspension configurations without reducing the wheels. In fact, since the torque to be transmitted by the drive shaft is high, the drive shaft must be dimensioned accordingly, which is generally incompatible with the legislative requirements of the maximum width of the vehicle.

Disclosure of Invention

The object of the present invention is to provide an improved differential gear unit for a vehicle, in particular a differential gear unit equipped with a locking system that is more compact in the lateral direction of the vehicle.

To this end, according to a first aspect, the invention relates to an assembly of a differential unit for a vehicle, the assembly comprising:

-a differential housing having a longitudinal axis;

differential side gears configured to be connected to a drive shaft connectable to wheels of a vehicle, the differential side gears being located inside the differential case and mounted in a manner rotatable about a longitudinal axis relative to the differential case.

-a locking system for locking the operation of the differential unit, the locking system comprising: a lock member movable between a release position and a lock position; and an actuation system for moving the locking member between the release position and the locking position;

wherein the locking member is located inside the differential case, and the locking member is configured to rotatably fix the differential case and the differential side gear.

Thus, according to the present invention, contrary to the prior art, the rotary members rotatably fixed to each other to lock the operation of the differential unit are the differential side gears and the differential case.

This allows the locking member to be positioned inside the differential case, and therefore the present invention enables space saving, particularly in the area adjacent to the differential unit in the lateral direction of the vehicle.

Thanks to this arrangement, the invention makes it possible to implement a locking system on a differential unit of a heavy vehicle having an independent wheel suspension configuration without reducing the wheels. However, the invention is not limited to this application and may also be used in vehicles having a rigid driven axle.

Another advantage of the present invention resides in the fact that: the rotationally locked connection between the components of the assembly can be realized on a larger diameter (e.g., approximately the outer diameter of the differential side gears) than in the prior art (typically approximately the diameter of the drive shaft). This results in less force being applied to the components of the assembly for the same input torque transmitted through the system. As a result, these components can be made of less resistant materials (i.e., less expensive materials) and/or can be reduced in size compared to the prior art, which results in cost savings and increased compactness.

Furthermore, in embodiments, the present invention can utilize the area of the differential unit where there is empty space available to receive at least a portion of the actuation system. The region may generally face the differential case in a direction orthogonal to the longitudinal axis.

The actuation system may include:

-a connecting device connected to the locking member in a rotationally fixed and axially fixed manner;

an actuating device which is able to move the locking member relative to the differential housing between the release position and the locking position via a connecting device.

It is emphasized that, although rotation and translation between the connecting means and the locking member is not possible, this does not necessarily mean that the two parts are fixed to each other.

Has the following structure:

the locking member is a rotating part located inside the differential case;

and the actuating means located outside the differential housing are preferably rotationally fixed for easy mounting and connection.

The problem that arises is solved by the invention in that the connecting device has an outer part and a through-going part.

The actuating means may be located outside the differential case, and the connecting means may comprise:

-an outer portion mounted on and outside of the differential case, wherein the outer portion is rotatably fixed to the differential case and is movable relative to the differential case along the longitudinal axis so as to allow movement of the locking member between the released position and the locked position.

-at least one through-going portion extending through the differential case peripheral wall for fixedly connecting, in use, the outer portion of the connecting device and the locking member.

It must be noted that the through portion of the connecting device may extend through a cylindrical or radial portion of the peripheral wall of the differential case.

By "fixedly connecting" two parts is meant that the two parts are connected in a rotationally fixed and axially fixed manner. This does not necessarily mean that the two parts are fixed to each other. Axial and longitudinal means both: along or parallel to the longitudinal axis.

The locking member may be rotatably fixed to the differential case, and the locking member may be movable relative to the differential case along the longitudinal axis between:

a locking position in which the locking member is engaged with the differential side gear such that the locking member and the differential side gear are rotationally fixed to each other;

and a release position in which the locking member is spaced apart from the differential side gear.

Rotationally fixing the locking member with the differential side gear may be achieved by cooperation between at least one engagement portion of the locking member and at least one engagement portion of the differential side gear. These engaging portions may be of any kind as long as they cause the locking member and the differential side gear to be rotationally fixed to each other in the engaged position. Preferably, said mutual engagement is achieved by interference.

According to one embodiment, the locking member comprises at least one relief of projections or recesses configured to cooperate, in the locking position, with at least one corresponding relief of recesses or projections provided on the differential side gear. Preferably, the locking member is annular and the at least one projection or recess relief of the locking member is in the form of a plurality of teeth extending from the periphery of the locking member and configured to engage with a set of teeth arranged on the differential side gear. The plurality of teeth preferably extend axially from a periphery of the locking member. The locking member then forms a dog clutch. With respect to the differential side gear, the differential side gear may have an annular shape, and the one set of teeth preferably protrudes axially outward from a face of the differential side gear opposite to a face including a separate set of teeth that meshes with at least one differential side pinion of the differential unit.

The inner face of the differential case may be provided with at least one convex or concave relief and the outer face of the locking member may be provided with at least one corresponding concave or convex relief. Preferably, the inner face of the differential case and the outer face of the locking member are provided with corresponding longitudinally extending splines that allow relative longitudinal sliding movement between the locking member and the differential case and prevent relative rotational movement between the locking member and the differential case about the longitudinal axis.

The or each through-portion of the connecting device may be engaged in a through-opening provided in a peripheral wall of the differential case, the through-portion being axially slidable in the through-opening and being rotatably fixed relative to the differential case. The through opening is preferably elongated in the longitudinal direction.

The locking member may comprise at least one receptacle of the or each through-portion of the connection means, preferably in the form of a through aperture provided in a peripheral wall of the locking member. The connecting device through-portion is preferably received in the through-opening, wherein there is no degree of freedom in the longitudinal direction.

The or each through aperture may be circumferentially elongate. This makes the manufacturing and installation process easier because the exact relative positions of the splines and the through-going aperture, which the connector through-portion may face, are not required to ensure that one locking member is installed inside the differential case.

In a variant, the receiving portion does not comprise any aperture. In such a variant, the connecting means through-portion may be formed in a single part with the locking member. The connector through-portion may be made as a single part with the locking member, or the connector through-portion may be made as a separate part but then permanently or removably secured to the locking member by any suitable means, such as gluing, welding, screwing or the like.

The outer part of the connection device may comprise an inner face provided with at least one protrusion or concave relief and the outer face of the differential case may be provided with at least one corresponding recess or convex relief so as to allow relative longitudinal sliding movement between the differential case and the outer part of the connection device and to prevent relative rotational movement between the differential case and the outer part of the connection device about the longitudinal axis. Preferably, the connection device inner face comprises at least two protrusions circumferentially spaced relative to each other and protruding from the inner face of the connection device outer portion, and the differential case outer face comprises at least two axially extending cavities circumferentially spaced relative to each other and arranged on the differential case outer face. In one embodiment, the cavity may be a parallelepiped. Alternatively, the inner face of the connecting device outer part and the outer face of the differential housing may be provided with corresponding splines.

The outer part of the connection device may comprise or consist of a ring.

The outer part of the connection means may comprise at least one receptacle of the or each through-portion of the connection means, preferably in the form of a bore or an internal annular recess. Providing a recess is more advantageous than providing a hole, because a recess facilitates positioning and thus the mounting process.

The connecting means through-going portion is preferably received in the bore or the inner annular groove with no freedom in the longitudinal direction.

In a variant, the receiving portion does not comprise any holes or grooves. In such a variant, the connecting device through-portion may form a single part with the connecting device outer portion. The connector through-portion may be made as a single part with the connector outer portion, or the connector through-portion may be made as a separate part but then permanently or removably secured to the connector outer portion by any suitable means, such as gluing, welding, screwing or the like.

The outer part of the connection means may comprise an outer face provided with an outer annular groove for receiving a part of the actuation means. The part of the actuating means is preferably received in the outer annular groove with no degree of freedom in the longitudinal direction. Alternatively, the outer part of the connection means may comprise an outer annular ridge for receiving a part of the actuation means, or the part of the actuation means may abut against the outer annular ridge.

In one embodiment, the actuation means and the outer portion of the connection means are free to rotate relative to each other about a longitudinal axis, the actuation means comprising: at least one finger engaged in an outer annular groove of the outer portion of the connection device; or a hollow for receiving an external annular ridge of the outer part of the connection device (such as a fork in contact with the opposite annular face of the ridge). If the outer part of the connecting means comprises an outer annular ridge, the actuating means preferably comprises a hollow to receive said ridge.

The fingers may move in the grooves during the rotational movement of the ring, and the fingers may also move the ring in the longitudinal direction. For example, the actuating means may be fixedly mounted on the differential carrier housing.

According to an embodiment, said at least one through-portion of the connection device comprises at least two pins, preferably four pins, more preferably eight pins, extending radially, which pins are regularly angularly spaced.

The assembly may further comprise a support member configured to be axially retained between the differential side gear and the inner collar of the differential case, and the support member further forms an internal abutment for preventing radially inward movement of the or each through-portion of the connecting means.

The present invention also relates to a differential case of a differential unit for a vehicle, the differential case being configured for receiving at least a portion of a differential, the differential case having: a peripheral wall having a substantially tubular shape; a longitudinal axis; an interior face; and an outer face, the differential case comprising:

-at least one raised or recessed relief on the inner face of the differential case for forming an internal sliding connection with a locking member of a differential unit along a longitudinal axis, said at least one raised or recessed relief on the inner face of the differential case preferably being in the form of longitudinally extending splines;

-at least one relief of projections or recesses on the outside face of the differential case, said at least one relief of projections or recesses on the outside face of the differential case forming an external sliding connection with a part of the actuation system of the locking member along the longitudinal axis, said at least one relief of projections or recesses on the outside face of the differential case preferably being in the form of at least two circumferentially spaced-apart parallelepiped cavities;

at least one through opening provided in the peripheral wall, configured to form a sliding connection with a part of the actuation system of the locking member along the longitudinal axis, the through opening preferably being elongated in the longitudinal direction.

The differential case may be configured to cooperate with the differential side gears and the locking system for forming an assembly as previously described.

The invention also relates to a differential side gear for a differential unit of a vehicle, the differential side gear having an annular shape and a longitudinal axis and comprising two opposite faces, the differential side gear being provided with a central hole for receiving a drive shaft in a rotationally fixed manner, the drive shaft being connectable to a wheel of the vehicle, the differential side gear comprising a first set of teeth for meshing with at least one differential side pinion of the differential unit, the differential side gear further comprising at least one relief of projections or recesses, the relief of projections or recesses being different from the first set of teeth or having a different orientation with respect to the first set of teeth, the relief of projections or recesses being adapted to surround a locking member of the differential unit by engagement of a corresponding engagement portion of the locking member in the relief of projections or recesses, preferably between the differential side gear and the locking member The longitudinal axis forms a rotationally coupled connection. The differential side gears may be configured to cooperate with the differential case and the locking system for forming an assembly as previously described.

The present invention also relates to a lock member for locking operation of a differential gear unit of a vehicle, the lock member being configured to be mounted inside a differential case of the differential gear unit, the lock member having: a peripheral wall having a generally cylindrical shape with a longitudinal axis; an interior face; and an exterior face, the locking member comprising:

-at least one relief of projections or recesses on the outer face of the locking member, said at least one relief of projections or recesses forming an outer sliding connection along the longitudinal axis, said at least one relief of projections or recesses preferably being in the form of longitudinally extending splines;

at least one engagement portion for forming a rotationally coupled connection with a differential-side gear of the differential unit about a longitudinal axis, preferably in the form of a plurality of teeth extending (e.g. axially extending) from the periphery of the locking member;

at least one receptacle of a part of the actuation system of the locking member, preferably in the form of a through aperture provided in the peripheral wall

The locking member may be configured to cooperate with the differential case and the differential side gears for forming an assembly as previously described.

The present invention also relates to a ring for a locking system of a differential unit of a vehicle, the ring being configured to be mounted around a differential case of the differential unit and having a longitudinal axis, an inner face and an outer face, the ring comprising:

-at least one relief of projections or recesses on the inner face of the ring for forming an inner sliding connection with the differential case along the longitudinal axis, preferably in the form of at least two circumferentially spaced projections;

at least one receptacle on the inner face of the ring, belonging to a part of the actuation system of the locking system, preferably in the form of a hole or an internal annular groove;

an external annular groove or an external annular ridge on the external face of the ring, intended to receive a portion of the actuating means belonging to the locking system.

The ring may form part of a locking system configured to cooperate with the differential case and the differential side gears to form an assembly as previously described.

According to another aspect, the present invention relates to a differential gear unit of a vehicle, which includes a differential carrier case, and in which the following are mounted:

-an assembly as described above;

-a crown wheel having a longitudinal axis, the crown wheel being arranged to be driven in rotation about said longitudinal axis by an input shaft;

-a differential arranged substantially inside the crown wheel and comprising: a differential-side pinion that rotates relative to a spider attached to the crown wheel; and two differential side gears each connected to at least one differential side pinion and to a drive shaft connectable to a wheel of the vehicle outside the differential carrier housing;

-a differential housing arrangement containing a differential and a portion of a drive shaft, said differential housing arrangement comprising two differential housings, both of which are fixed to a crown wheel on both sides of the crown wheel, the differential housings having the same longitudinal axis as the crown wheel.

Wherein a differential case and a differential side gear located inside the differential case are part of the assembly.

In an embodiment, the actuating device is mounted in a rotationally fixed manner on the differential carrier housing, i.e. on and inside the differential carrier housing wall.

The locking system may be located inside the differential carrier housing in a region generally facing one of the differential housings in a direction orthogonal to the longitudinal axis.

The locking member may be annular and is preferably arranged around a drive shaft.

The differential unit may further comprise a support means on both sides of the crown wheel, which support means is attached to the differential carrier housing and which support means comprises an annular portion in which is received: a portion of at least one drive shaft inside the differential case; and a bearing surrounding the differential case, the locking member being located between the differential side gear and the corresponding bearing according to a projection along the longitudinal axis.

The present invention also relates to a differential gear unit of a vehicle, which includes a differential carrier case, and in which the following are mounted:

-a crown wheel having a longitudinal axis, the crown wheel being arranged to be driven in rotation about said longitudinal axis by an input shaft;

-a differential arranged substantially inside the crown wheel and comprising: a differential-side pinion that rotates relative to a spider attached to the crown wheel; and two differential side gears each connected to at least one differential side pinion and to a drive shaft connectable to a wheel of the vehicle outside the differential carrier housing;

-a differential housing arrangement containing a differential and a portion of a drive shaft, said differential housing arrangement comprising two differential housings, each secured to a crown wheel on both sides of the crown wheel, the differential housings having the same longitudinal axis as the crown wheel;

-a locking system for locking the operation of the differential unit, the locking system comprising: a lock member movable between a release position and a lock position; and an actuation system for moving the locking member between the release position and the locking position;

wherein:

the locking system is located inside the differential carrier housing in a region facing substantially towards one differential housing in a direction orthogonal to the longitudinal axis.

And/or the locking member is configured to rotationally fix the differential case and the differential side gear.

The invention also relates to a driven wheel system for a vehicle.

According to one embodiment, the driven wheel system comprises: at least one left wheel and one right wheel, each wheel being connected by a drive shaft to a differential unit as previously described: at least one joint (e.g., a universal joint, a homotype joint, etc.); a lower arm hinged at both ends; and preferably an upper arm, which is hinged at both ends.

According to another embodiment, the driven wheel system forms an axle and comprises:

-a differential gear unit as described above;

-an axle housing constituting a second housing part designed to be assembled to a first housing part for forming a differential carrier housing and which at least partly contains a drive shaft;

-at least one wheel connected to one end of each drive shaft.

The invention also relates to a vehicle comprising at least one driven wheel system as described above.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

Drawings

The following is a more detailed description of embodiments of the invention, reference being made to the accompanying drawings by way of example.

In the drawings:

FIG. 1 is a schematic view of an underside of a vehicle showing a driven wheel system including a differential gear unit according to an embodiment of the invention;

FIG. 2 is a schematic view of a first embodiment of a driven wheel system;

FIG. 3 is a schematic view of a second embodiment of a driven wheel system;

FIG. 4 is a perspective view of the differential unit;

FIG. 5 is a perspective partial cut-away view of a differential unit showing an assembly including a differential case, locking members, differential side gears and a ring according to an embodiment of the invention.

FIG. 6 is a perspective view of the assembly;

FIG. 7 is a perspective partial cut-away view of the assembly;

FIG. 8 is a cross-sectional view of the assembly;

FIG. 9 is an exploded view of the assembly of FIG. 7, showing the installation step of the assembly;

FIG. 10 is a perspective partial cut-away view of a differential housing;

FIG. 11 is a perspective view of a differential housing;

FIG. 12 is a perspective view of the locking member;

fig. 13 and 14 are perspective views of the differential side gears viewed from opposite sides;

fig. 15 is a perspective view of a ring.

Detailed Description

As shown in fig. 1, the vehicle 1 includes: an engine 2, the engine 2 driving an input shaft 3 having an axis 13; and a front axle 4, the front axle 4 being connected to a front wheel 5.

The vehicle 1 further comprises at least one driven wheel system 6, the or each driven wheel system 6 having an axis 12, and a differential unit 10, the differential unit 10 comprising a differential 15 and at least part of two drive shafts 11. Each drive shaft 11 has a first end connected to a differential 15 and a second end connected to at least one wheel 8. In the illustrated embodiment, the vehicle 1 includes a first driven rear wheel system 6a and a second driven rear wheel system 6b, and the second driven rear wheel system 6b is located rearward of the first driven rear wheel system 6 a. Each rear wheel system 6a, 6b may comprise two wheels 8 on both sides, thus forming a double-mounted tyre arrangement.

The additional shaft 9 connects the input shaft 3 to the differential unit 10 of the second driven rear wheel system 6b through the differential unit 10 of the first driven rear wheel system 6a, and the additional shaft 9 is an input shaft for the differential unit 10 of the second driven rear wheel system 6 b.

The invention is of particular interest for vehicles with independent wheel configurations as schematically shown in fig. 2. In this configuration, the left wheel 8 and the right wheel 8 are each connected to the differential gear unit 10 by: a drive shaft 11, at least one joint 11a (for example a universal joint, i.e. a cardan joint, or another type of joint), lower arms 14b hinged at both ends and preferably upper arms 14a hinged at both ends.

However, the invention may also be used for vehicles with a rigid axle construction as schematically shown in fig. 3. In this configuration, the driven wheel system forms an axle comprising the axle housing 7 containing the differential 15 and a portion of the drive shaft 11. The axle housing 7 may constitute a second housing part designed to be assembled to the first housing part for forming a differential carrier housing.

The present invention may be applied to heavy vehicles such as trucks, buses and construction equipment, as well as to medium-sized vehicles. Although described below with reference to a rear wheel system, it must be noted that the present invention may be used on another driven wheel system, for example, on a driven front wheel system.

Reference is now made to fig. 4, 5 and 8.

The differential unit 10 includes a differential carrier case 20, the differential carrier case 20 being made of a first case portion 20a and a second case portion 20b (shown in fig. 4), the first case portion 20a and the second case portion 20b being fixed to each other by appropriate fasteners (not shown). In a vehicle having a rigid axle configuration, the second housing portion 20b may be formed by the axle housing 7 (see fig. 3).

A crown wheel 22 having a longitudinal axis 23 is located inside the differential carrier housing 20. The crown wheel 22 is driven by the input shaft 3 in rotation about said longitudinal axis 23 by engagement of teeth arranged on a pinion (not shown) mounted on said input shaft 3 with teeth arranged on the crown wheel 22 (not shown).

As shown in fig. 8, the longitudinal direction X is defined as a direction parallel to the longitudinal axis 23 of the crown wheel 22. In the operating position, i.e. when the differential unit is mounted under the vehicle 1, as shown in fig. 1, the longitudinal direction X corresponds to the transverse direction Y' of the vehicle 1, i.e. the axis 12 of the driven wheel system 6. When the vehicle 1 is on a horizontal surface, the direction X is substantially horizontal.

Further, the lateral direction Y is defined as a direction that is orthogonal to the longitudinal direction X and is substantially horizontal when the vehicle 1 is on a horizontal surface. The direction Y corresponds to the longitudinal direction X' of the vehicle 1. The axis 13 of the input shaft 3 is parallel to the transverse direction Y, i.e. the longitudinal direction X' of the vehicle 1.

Further, the direction Z is defined as a vertical direction when the vehicle 1 is on a horizontal surface.

The invention will be described in the case where the vehicle 1 is on a horizontal surface.

Inside the crown wheel 22, a differential 15 is arranged, which differential 15 comprises: differential-side pinions 16, for example, four differential-side pinions, the differential-side pinions 16 being fitted on a spider 17 attached to the crown wheel 22; and two differential side gears 18. Each of the differential side gears 18 meshes with at least one of the differential side pinions 16, and is fastened to a first end of one of the drive shafts 11. The differential-side pinion 16 is not shown in fig. 5; the differential-side pinion 16 is shown in fig. 8.

Inside the differential carrier housing 20, the differential unit 10 further comprises a differential housing arrangement 24, which differential housing arrangement 24 contains the differential 15 and a portion of the drive shafts 11, i.e. the portion of each drive shaft 11 located near the first end of said drive shaft 11. The differential housing arrangement 24 is secured to the crown wheel 22. The differential case arrangement 24 may be composed of two parts, namely two differential cases 24a, 24b, each forming a sleeve in such a way as to surround the corresponding differential side gear 18 and partially surround the drive shaft 11, said differential cases 24a, 24b being fastened on both sides of the crown wheel 22.

Thus, on each side of the crown wheel 22, a differential side gear 18 is mounted at a first end of the drive shaft 11 in a rotationally fixed manner. Furthermore, the differential side gears 18 and the drive shaft 11 are each mounted rotatably about the longitudinal axis 23 relative to the differential cases 24a, 24 b. The bearing 26 may be mounted around the drive shaft 11 between the drive shaft 11 and the differential housings 24a, 24 b.

The crown wheel 22, differential 15, and differential case 24 are rotating components that are internal to the differential carrier case 20 and rotate relative to the differential carrier case 20. The crown wheel 22, the differential 15 and the differential housing 24 are mounted on the inside of the speed carrier housing 20 by means of two support devices 30 arranged on both sides of the crown wheel 22. Each support device 30 is attached to the differential carrier housing 20 and comprises an annular portion in which a portion of one drive shaft 11 inside the differential housings 24a, 24b and a bearing 27 surrounding the differential housings 24a, 24b are received. More specifically, the bearing 27 may have an inner ring mounted on the differential case 24a, 24b and an outer ring mounted on the support device 30. The bearing 27 is preferably a conical bearing.

The differential unit 10 also includes a locking system 100 (see fig. 8) for locking operation of the differential unit. The latch system 100 includes: a lock member 50, the lock member 50 being movable between a release position and a lock position; and an actuating system 60, the actuating system 60 being for moving the locking member between said release position and said locking position.

The entire locking system 100 may be located inside the differential carrier housing 20. The locking system 100 may be located in a direction orthogonal to the longitudinal axis 23 in a region generally facing one of the differential housings, which preferably faces the differential housing 24a that does not extend inside the crown wheel 22.

The differential case 24a, differential side gears 18 and locking system form an assembly 110 such as that shown in fig. 6 and 7.

According to the present invention, the locking member 50 is located inside the differential case 24a and is configured to rotatably fix the differential case 24a and the corresponding differential side gear 18 (i.e., the differential side gear 18 located in the differential case 24 a).

The locking member 50 may be annular, with a peripheral wall 51 having a generally cylindrical shape. The locking member 50 is preferably arranged around one of the drive shafts 11. The locking member 50 may be located between the differential side gear 18 and a corresponding bearing 27 according to a projection along the longitudinal axis 23, the bearing 27 being mounted between the support device 30 and the differential case 24 a.

As shown in fig. 8, the actuation system 60 may include:

a connecting means 70, which connecting means 70 is connected to the locking member 50 in a rotationally fixed and axially fixed manner;

an actuating means 65, which actuating means 65 is able to move the locking member 50 relative to the differential housing 24a between said release position and said locking position via a connecting means 70.

In embodiments, the actuation device 65 may be located outside of the differential case 24 a. Then, the connecting device 70 includes:

an outer portion 80 mounted on the differential case 24a and external to the differential case 24a, the outer portion 80 being rotatably fixed to the differential case 24a and movable relative to the differential case 24a along the axis 23, allowing the locking member 50 to move between the released position and the locked position;

at least one through-going portion 71, said at least one through-going portion 71 extending through a peripheral wall of the differential case 24a for fixedly connecting, in use, the outer portion 80 of the connecting device 70 and the locking member 50.

By "fixedly connecting" two parts is meant that the two parts are connected in a rotationally fixed and axially fixed manner. This does not necessarily mean that the two parts are fixed to each other.

With this arrangement, the present invention enables the transfer of actuation movement from the non-rotating component (i.e., the actuation device 65) to the moving locking member 50 surrounded by the rotating differential case 24 a. Having a non-rotating actuating means 65 makes this embodiment simpler, since wires and pipes can be easily connected.

The locking member 50 may be rotatably fixed to the differential case 24a, and may be movable relative to the differential case 24a along the longitudinal axis 23 between:

a release position in which the locking member 50 is spaced apart from the differential side gear 18;

and a locked position in which the locking member 50 and the differential side gear 18 are rotationally fixed to each other by cooperation between at least one engagement portion of the locking member 50 and at least one engagement portion of the differential side gear 18. In the locked position, the differential case 24a and the differential side gears 18 rotate at the same speed about the longitudinal axis 23, and the differential 15 is locked.

By "rotatably fixed" is meant that the locking member 50 is mounted in a rotationally fixed manner relative to the differential side gear 18.

In other words, according to the present invention, the differential unit operation is locked by locking the rotation between the differential side gear 18 and the differential case 24a, which results in indirectly locking the rotation between the drive shaft 11 and the crown wheel 22.

As shown in fig. 6 to 11, the differential case 24a may have a peripheral wall 40, the peripheral wall 40 having a generally tubular shape and not generally having a constant diameter. Said differential case 24a has, in the mounted position, the same longitudinal axis 23 as the crown wheel 22; the differential case 24a also has an inner face 41 and an outer face 42. As shown in fig. 10, the differential case 24a may be made of two half-tubular half-shells assembled together along a plane containing the longitudinal axis 23.

On the inner face 41, the differential case 24a may include means for forming an internal sliding connection with the locking member 50 along the longitudinal axis 23. These means may comprise at least one raised or recessed relief, such as longitudinally extending splines 43.

A "sliding connection" between two parts is a connection that allows relative sliding of the parts along the longitudinal axis 23 but prevents relative rotational movement between the parts about the longitudinal axis 23.

On the outer face 42, the differential case 24a may comprise means for forming an external sliding connection along the longitudinal axis 23 with a portion of the actuation system 60, more particularly with an external portion 80 of said actuation system 60. These means may comprise at least one relief of projections or recesses. In one embodiment, these means may be in the form of at least two circumferentially spaced cavities 44. The cavity 44 may be a parallelepiped. At least four, and more preferably eight cavities, preferably regularly angularly spaced, may be provided on the outer face 42 of the differential case 24 a. Alternatively, the differential case 24a may be provided with external splines and the actuation system outer portion 80 may be provided with corresponding internal splines.

As shown in fig. 11, the differential case 24a may have a portion 45 on the crown side, the portion 45 having a larger diameter than the other portion 46 and forming a shoulder 47. The cavity 44 may be arranged on said portion 45 having a larger diameter and may open in a shoulder 47. This allows the outer part 80 of the connecting device 70 to be mounted from the position shown in fig. 9 by a sliding movement along the longitudinal axis 23.

Differential case 24a may include at least one through opening 48 disposed in peripheral wall 40. The or each through opening 48 is configured to form a sliding connection with a portion of the actuation system 60 of the locking member 50, more specifically with the through portion 70 of said actuation system 60, along the longitudinal axis 23. The or each through opening 48 is preferably elongate in the longitudinal direction X. At least four, and more preferably eight, through openings 48 may be provided, with the through openings 48 preferably being regularly angularly spaced on the outer face 42 of the differential case 24 a. Each through opening 48 may be located between two adjacent cavities 44.

As shown in fig. 12, the locking member 50 may have a generally cylindrical peripheral wall 51 and, in the installed position, the same longitudinal axis 23 as the crown wheel 22. The locking member 50 also has an inner face 53 and an outer face 54.

The locking member 50 may have longitudinally extending splines 55 on its outer face 54 for cooperating with the splines 43 of the differential case 24a, or another means for providing a sliding connection between the locking member 50 and the differential case 24a along the longitudinal axis 23.

The locking member 50 may also have at least one engagement portion for forming a rotationally coupled connection with the differential side gear 18 about the longitudinal axis 23. Preferably, the engagement portion is in the form of a plurality of teeth 56, the plurality of teeth 56 extending from the periphery of the locking member 50. Teeth 56 may extend axially from the periphery of locking member 50; the teeth 56 may have a parallelepiped shape. In other words, the locking member 50 may be a dog clutch.

The peripheral wall 51 of the locking member 50 may also comprise at least one through aperture 57, which through aperture 57 is intended to receive a portion of the actuation system 60 of the locking member 50, more particularly the through portion 70 of said actuation system 60. At least four, more preferably eight through-holes 57 may be provided, which through-holes 57 are preferably regularly angularly spaced on the peripheral wall 51 of the locking member 50. The through-going apertures 57 are preferably circumferentially elongated.

As shown in fig. 13 and 14, the differential side gear 18 preferably has an annular shape. The differential side gear 18 may include a disk-shaped plate 73, the disk-shaped plate 73 having two opposite faces, one face 74 facing the crown wheel 22 and an opposite face 75. In the mounted position, the differential side gear 18 has the same longitudinal axis 23 as the crown wheel 22.

The differential side gear 18 is provided with a central bore 76 for receiving the drive shaft 11 in a rotationally fixed manner. To this end, the central bore 76 may include internal longitudinally extending splines 77. On the face 74 facing the crown wheel 22, the differential side gear 18 includes a first set of teeth 78 for meshing with at least one differential side pinion 16 of the differential unit 10.

Additionally, the differential side gear 18 may include a second set of teeth 79, the second set of teeth 79 preferably projecting outwardly from an outer peripheral region of the differential gear 18 and axially from the face 75 for engagement with the teeth 56 of the locking member 50. Alternatively, the differential side gear 18 and the locking member 50 may be provided with other complementary engagement portions for forming a rotationally coupled connection between the differential side gear 18 and the locking member 50 about the longitudinal axis 23. Preferably, the engagement may be achieved by interference, for example, between complementary raised or recessed undulations.

It is advantageous to provide teeth 79 on the differential side gear 18 that cooperate with the locking member 50. In fact, first, this takes advantage of the fact that the differential side gears 18 are made of high-grade material. Therefore, it is not necessary to perform a surface treatment for imparting high resistance to the teeth 79, and it is also not necessary to provide a separate member made of a high-grade material to form the teeth 79. Secondly, this enables the entire differential side gear 18 including the second set of teeth 79 to be manufactured in the same precision forging operation at one time. The precision forging is the current manufacturing process for a conventional differential side gear 18 provided with a first set of teeth 78. The present invention does not involve additional costs since no additional manufacturing steps are required.

An embodiment of the outer portion 80 of the connection device 70 is shown in fig. 15.

According to this non-limiting embodiment, the connection means outer portion 80 comprises or forms a ring having an inner face 81 and an outer face 82. The ring is configured to fit around the differential case 24 a. In the mounted position, the ring has the same longitudinal axis 23 as the crown wheel 22.

The ring 80 may include at least two circumferentially spaced protrusions 84 on its inner face 81, the protrusions 84 being longitudinally slidable within the cavity 44 of the differential case 24 a. Alternatively, other means for forming an internal longitudinal sliding connection with the differential case 24a may be provided. The projection 84 may be a parallelepiped having a longitudinal dimension less than the longitudinal dimension of the cavity 44 so as to be capable of guiding sliding movement throughout the entire range of movement. The lateral dimension of the projection 84 may be substantially the same as the lateral dimension of the cavity 44 (with working clearance) to prevent relative rotation.

Still on the inner face 81 of the ring 80, the ring 80 may comprise an inner annular groove 85 for receiving a portion of the actuation system 60, more particularly the through portion 71 of the connection means 70 of said actuation system 60. Alternatively, the inner annular groove 85 may be replaced by a hole or another receiving portion, since the through portion 71 and the ring 80 are rotatably fixed to each other.

The ring 80 may include an outer annular groove 86 on its outer face 82 for receiving a portion of the actuating means 65. Alternatively, the ring 80 may comprise an outer annular ridge for receiving a portion of the actuating means 65.

The actuating means 65 may comprise a hydraulic actuator 66 or any other actuator and a spring 67, the spring 67 being used to bias the actuating means towards the release position. Preferably, the actuating device 65 is mounted in a rotationally fixed manner on the differential carrier housing wall and inside the differential carrier housing 20. Such a construction is simpler, in particular with regard to the mounting and sealing of the conduits provided for carrying the actuating fluid. With this configuration, the linkage outer portion 80 is a rotating portion relative to the actuator 65.

The actuating means 65 may comprise at least one finger 68, said at least one finger 68 being engaged in an outer annular groove 86 of the connecting means outer portion 80, such that the actuating means 65 and the outer portion 80 of the connecting means 70 are free to rotate relative to each other about the longitudinal axis 23. Preferably, however, a relative longitudinal sliding is not possible, so that a longitudinal movement of the actuating means 65 results in the same longitudinal movement of the connecting means outer part 80 between the release position and the locking position of the locking member 50. If the ring 80 comprises an external annular ridge instead of an external annular groove, the actuating means 65 may comprise a hollow for receiving said ridge.

In an embodiment, the through portion 71 of the connection device 70 comprises at least two, preferably four, more preferably eight radially extending pins, which are regularly angularly spaced.

Each through portion 71, i.e., each pin 71, is engaged in:

the inner annular groove 85 of the ring 80, in which there is no degree of freedom in the longitudinal direction X;

one through opening 48 provided in the differential case peripheral wall 40, said pin 71 being able to slide axially in said through opening 48 following elongation of said pin 71, but said pin 71 being rotatably fixed with respect to the differential case 24a, since for example the transverse dimension of the pin 71 is substantially the same as the transverse dimension of the through opening 48;

and one through aperture 57 provided in the locking member peripheral wall 51, wherein there is no degree of freedom in the longitudinal direction X.

Thus, the locking member 50 is fixedly connected to the connecting device outer portion 80. As a result, the longitudinal movement of the actuating means 65 results in the same longitudinal movement of the locking member 50 between the release position and the locking position of the locking member 50. In the installed position, the locking member 50 and the outer portion 80 generally face each other in a radial direction (i.e., a direction orthogonal to the longitudinal axis 23).

The pin 71 serves as a part for transmitting the movement of the connecting device outer portion 80 to the locking member 50. However, the pin 71 does not transmit torque and is only subjected to the thrust of the actuating means 65, which is significantly lower than torque. Therefore, the pin 71 or other through portion does not need to be sized to withstand a large force.

The longitudinal movement of the locking member 50 is stopped in both directions. This may be achieved by abutment in cooperation with the locking member 50 itself or by limiting the stroke of the actuating means 65.

In the event that the pin 71 or other connector through-portion is not secured to the connector outer portion 80 and/or the latch member 50, the assembly 110 may include a support member 90 (see fig. 7), the support member 90 forming an internal abutment for preventing radially inward movement of the or each through-portion 71 of the connector 70. It must be noted that in embodiments in which the through portion 71 is fixed to the outer portion 80 and/or to the locking member 50, no such internal abutment for the through portion 71 is required. The support member 90 may be axially retained between the differential side gear 18 and the inner collar 28 of the differential case 24 a. As shown in fig. 5, the bearings 26 may be located between the inner collar 28 and the differential side gears 18. However, other embodiments regarding the location of the bearing 26 are contemplated. In a vehicle having an independent wheel configuration, the bearing 26 may be omitted, as the bearing 26 may be replaced with a hub bearing.

As shown in fig. 8, the mechanical connection between the rotating components of the assembly 110 is made by splines and teeth on a diameter D that is quite high and higher than the prior art diameter, which increases the resistance of the assembly components to a determined torque.

The trend in the heavy-duty transportation industry is to steer an independent wheel suspension (IRS) from a rigid axle to improve a number of features (dynamic performance, volumetric capacity of battery/fuel …, wheel alignment, comfort …). In an IRS arrangement, for reasons of mechanical strength, in order to provide sufficient space to allow operational movement of components and to improve fuel efficiency, the drive shaft must have a minimum length that may not be readily compatible with legal constraints (i.e. a prescribed maximum lateral length of the vehicle).

The present invention provides a solution for implementing a differential unit with a locking system on a vehicle with an IRS arrangement and with double mounted tires without reducing the wheels by providing a differential unit with a smaller dimension in the transverse direction of the vehicle.

The advantages of the present invention are all even more significant since IRS is a key solution for developing an optimized electric drive train, which is a promising development in the transportation industry.

Although the invention has been described for a rear wheel system, the invention may be used in another driven wheel system, in particular in a front driven wheel system. Further, the vehicle may have a different configuration from that shown in fig. 1. In particular, the present invention may be applied to an electric vehicle.

It should be understood that the present invention is not limited to the embodiments described above and shown in the drawings; rather, the skilled person will recognise that many modifications and variations are possible within the scope of the appended claims.