Cross-Reference to Related Applications

This patent application claims priority of Italian Patent Application No. 102021000016187 filed on June 21, 2021, the entire disclosure of which is incorporated herein by reference.

Technical Field of the Invention

The present invention concerns an improved bracket for a suspension system for a heavy vehicle, in particular a suspension system for a heavy vehicle provided with an electronic traction.

State of the Art

Heavy vehicles such road transport vehicles, e.g. trucks, are more and more electrified for reducing their polluting emissions. In particular, such vehicles may be hybrid vehicles or purely electric vehicles.

In particular, the electrified vehicles comprises at least an electric drive rear axle, i.e. a rear drive axle provided with electric machines such as motors/generators configured to impart a torque on the axle to allow its motion or to recharge battery modules of the vehicle when this latter is braking.

Such battery modules are usually placed in the proximity of the electric machines of the electric axle in order to provide energy exchange with electric machines in an efficient way.

However, as known, an axle of a vehicle is connected to the chassis of this latter via a suspension system configured to dampen the forces acting between the road and the chassis.

If a vehicle is provided with an electric axle as described above, the presence of the electric batteries increases the encumbrance around the chassis. Accordingly, known suspension systems for heavy vehicles are not suitable because of the presence of the electric axle.

Therefore, the need is felt to provide new arrangement of suspension system that can be mounted to an electric axle and that provides at least the same mechanical properties of the known suspension systems.

An aim of the present invention is to satisfy the above mentioned needs in a compact, optimized and cost effective way. Subject and Summary of the Invention

The aforementioned aim is reached by a suspension system and a vehicle as claimed in the appended independent claims.

Preferred embodiments of the invention are realized according to the claims dependent on or related to the above independent claim. Brief Description of the Drawings

For a better understanding of the present invention, a preferred embodiment is described in the following, by way of a non-limiting example, with reference to the attached drawings wherein:

• Figure 1 is a perspective view showing a suspension system comprising a bracket according to the present invention;

• Figure 2 is a perspective view of the bracket of the suspension system according to the invention;

• Figure 3 is a lateral view of a portion of the suspension system of figure 1;

• Figure 4 is a perspective view of the portion of figure

3;

• Figure 5 is a bottom view of the suspension system of figure 1; and

• Figure 6 is a perspective view of the suspension system of the invention provided with a mudguard.

Detailed Description of Preferred Embodiments of the Invention

Figure 1 discloses a suspension system 1 for connecting an axle 2 of a heavy vehicle to a chassis 3 thereof. The chassis 3 comprises, as per se known, a pair of side members 4, 5 extending along a longitudinal axis A of the vehicle and transversally spaced apart.

It is noticed that the suspension system 1 may be provided for a work vehicle comprising a front axle (not shown) and a rear axle 2 that, as shown, may be provided with a single configuration (as shown) or a double axle configuration and extends along an axis B, transversal with respect to longitudinal axis A.

In particular, the axle 2 is an electric drive axle i.e. it is provided with electric machines that are fed by the at least one battery module (not shown) to provide torque to the wheels carried by the axle 2 or to receive electric energy generated by the electric machines when the vehicle is braking. Due to the presence of such electric machines, the axle 2 has a greater extension in the space laterally comprised between side members 4, 5 along axis A, both in forward and rearward direction. Accordingly, a suspension system 1 is provided between the chassis 3 and rear axle 2.

Making reference to figures 1 and 5, the suspension system 1 comprises a right side 1'' and a left side 1'. Since the right side 1'' and the left side 1' are symmetrically equal with respect to longitudinal axis A, only the left side 1' will be described for sake of brevity.

With reference to figures 1 and 3, suspension system 1 comprises a metallic beam 7, i.e. a spring beam, comprising a rear terminal portion 7a and a front terminal portion 7b extending along longitudinal axis A. The metallic beam 7 is connected to axle 2, as described below, in an intermediate portion 7c longitudinally comprised between front and rear terminal portions 7b, 7a.

Each the front and rear terminal portions 7b, 7a are connected to chassis 3, i.e. to side member 5, via an air bellow such as an air bellow 8 interposed in a vertical direction between the chassis 3 and the metallic beam 7.

In particular, air bellow 8 comprises an upper portion 8a configured to be connected to chassis 3 and a lower portion 8b that is connected, e.g. via a threaded element, to the respective front or rear terminal portion 7b, 7a. As per se known, each air bellow 8 comprises an air bag 8c carried between the upper and lower portions 8a, 8b and configured to house pressurized air to dampen relative movements between such upper and lower portions 8a, 8b.

In particular, one between the rear air bellow 8 and the front air bellow 8 is connected to the chassis 3 via a standard bracket 9 while the other is connected to the chassis 3 via a multipurpose bracket 10 according to the invention and detailed described in the following. In the disclosed embodiment, the front air bellow is connected to chassis 3 via the standard bracket 9 while the rear air bellow is connected to the chassis 3 via the multipurpose bracket 10.

The metallic beam 7 is furthermore connected to chassis 3, i.e. to side member 5, via a damper 11 interposed along the aforementioned vertical direction. In particular, the damper 11 is substantially vertical with respect to side member 5 / to ground.

Preferably, the damper 11 is a hydraulic damper, i.e. a cylinder, comprising a housing 11a that is carried by side member 5 and a stem lib that is connected to the metallic beam 7. As per se known, the stem lib is configured to move inside housing 11a against the action of a fluid contained in the housing 11a to dampen relative movement between the side member 5 and metallic beam 7.

The stem lib is connected to metallic beam 7 in a portion comprised between the intermediate portion 7c and one between the front terminal portion 7b or the rear terminal portion 7a, as specified in the following description .

In particular, the stem lib is connected to the metallic beam 7 via a hinge connection (not shown) configured to allow a rotation of terminal portion of stem lib about an axis parallel to an axis parallel to the longitudinal axis A of the vehicle. The casing 11a is instead connected to side member 5 via a hinge connection 12 configured to allow a rotation of terminal portion of casing 11a.

The metallic beam 7 is connected to the respective axle 2 via a connection assembly 15. Preferably the connection assembly foresees a screw fixation of the the intermediate portion 7c of metallic beam 7 above axle 2. Since such connection assembly is per se known, it will not be further described for sake of brevity. Suspension system 1 further comprises a transversal retaining element 20 configured to support transversal movements acting between the axle 2 and chassis 3 but allowing vertical movement between these latter elements.

In particular, the transversal retaining element 20 comprises a V-shaped rod 21 provided with a first arm portion 21' and a second arm portion 21'' each provided with a first portion and a second portion. The first portions are stably connected together while the second portions are spaced along transversal direction getting over from the first portion connection.

Accordingly, the first and second arm portions 21', 21'' are inclined in a horizontal plane with respect to longitudinal axis so that each between their second portions gets closer to a respective side member 4, 5. In greater detail, the first and second arm portions 21', 21'' are symmetrical with respect to longitudinal axis A.

Advantageously, the first arm portion 21' and the second arm portion 21'' are realized as one piece. The first portions thereof are connected to the axle 2 via a hinge connection 22 that allows the rotation of such first portions about an axis parallel to transversal axis B. More preferably, the first portions are connected to axle 2 in an upper portion thereof, more preferably via a flange 23 carried by the axle 2. The second portions of the first arm portion 21' and the second arm portion 21 are connected by a respective hinge connection 24 to the chassis 3. In the disclosed embodiment, the hinge connection 24 is realized with a flange element 25 carried in a cantilevered way from a respective side member 4, 5.

Such flange member 25 is fixed to the respective side member 4, 5 via fixing element such as threaded elements and furthermore defines the lateral support for a cross member

26 that connected together the side elements 4, 5. The suspension system 1 further comprises stop means 27 configured to avoid an excessive vertical motion of the axle 2 with respect to chassis 3. In particular, such stop means

27 comprise a flange 28 fixedly carried by chassis 3 , e.g. by an intermediate element (not shown) carried by side members 4, 5 and configured to cooperate at contact with an end stop buffer (not shown) fixedly carried on the axle 2 when its motion exceed a predetermined height.

The suspension system 1 further comprises a stabilizer bar 30 configured to dampen possible torque acting between the axle 2 and chassis 3. The stabilizer bar 30, best shown in figure 5, comprises essentially a substantially straight portion 30' and a pair of terminal portions 30' . The terminal portions 30' are connected to the straight portion 30' via respective curved portions 30'''.

The stabilizer bar 30 is placed underneath the axle 2 and the metallic beam 7.Advantageously, the straight portion 30'is carried by metallic beam 7 and the terminal portions are carried by the multipurpose bracket 10 as detailed herein under.

Furthermore, the terminal portions 30''extends substantially perpendicular with respect to the straight portion 30', i.e. along longitudinal axis A and are both placed on the same side with respect to this latter. Therefore the stabilizer bar 30 defines a substantially

U-shaped path in a horizontal plane wherein the straight portion 30'is placed between the air bellows 8 and the respective axle 2.

The curved portions 30 ^,,f are positioned externally with respect to side members 4,5 so that they can swivel without interfering with the axle 2 or any further element attached to side members 4,5 such as battery modules.

In greater detail, the straight portion 30'is carried by metallic beam 7 via bearing means 36. In particular, bearing means 36 are directly carried by the beam 7 underneath this latter.

Suspension system 1 further comprises a longitudinal retaining element 35 configured to support longitudinal movements acting between the axle 2 and chassis 3 but allowing vertical movement between these latter elements.

In particular, longitudinal retaining element 35 comprises a rod 36 connecting axle 2 to chassis 3. In particular, the rod 36 connects axle 2 via beam 7 to a front hanger 37 fixedly carried by side member 4, 5, i.e. it rod 36 is directly connected to beam 7.

In greater detail rod 36 comprises a first terminal portion 36a and a second terminal portion 36b along axis A and an intermediate portion 36c comprised between these latter.

The first terminal portion 36a is connected to the front hanger 37 via a hinge 38 and the second terminal portion 36b is connected to beam 7 via a further hinge 38. Both hinges 38 are configured to allow a motion about an axis parallel to transversal axis B of the respective terminal portion 36a, 36b. It is noticed (see figure 5) that the rod 36 is completely placed laterally outside with respect to the space comprised by side member 4,5.

Front hanger 37 comprises an upper portion 31 configured to allow the fixation of the front hanger 37 to the respective side member 4,5 and a lower portion 31 configured to allow the connection of the rod 31 to the same.

The upper portion 31 defines a plurality of holes configured to allow the fixation of the front hanger 37 to the side member 4,5 and has a longitudinal extension greater with respect to lower portion 31 . In other words, a intermediate portion 31 connecting upper and lower portions 37 , 31 has a tapered cross-section along longitudinal axis A.

Preferably, the hinge 38 between rod 36 and lower portion 31 of front hanger 37 is realized between a pair of terminal legs extending spaced apart from lower portion 32 defining a space for accommodating the rod 36 and providing a support for hinge 38.

The multipurpose bracket 10 according to the invention, shown in detail in figure 2, is configured at least to allow the connection of the air bellow 8 and of a connection element 50 configured to allow the connection to stabilizer bar 30 as detailed below.

Moreover, the multipurpose bracket 10 may be configured to allow the connection of a support element 60 configured to carry an element of the vehicle, in particular a mudguard 70 (see figure 6).

In detail, the multipurpose bracket 10 comprises a main plate 40, a first connection point 41 and a second connection point 42. The main plate 40 has a shape that may vary according to the position needed to first and second connection points 41, 42.

Furthermore, the multipurpose bracket 10 is provided with a plurality of fixation points 43 to allow the fixation of the main plate 40 to side member 5. In particular, the fixation points 43 may be realized as holes realized in the main plate 40.

Advantageously, the first connection point 41 is realized as a plate element that extends substantially perpendicular to the main plate 40 underneath a lower edge of this latter and is configured to allow the fixation of the air bellow, e.g. via two holes 41'.

Advantageously, the second connection point 42 defines a cylindrical seat 42' realized in a protruding portion extending longitudinally cantilevered with respect to main plate 40.

In greater detail the connection element 50 is provided with a lower end connected to terminal portion via a lower hinge 51 and an upper end connected to chassis 3 via an upper hinge 52. Hinges 51, 52 are both configured to allow a rotation about an axis parallel to transversal axis B.

According to the above, the lower hinge 51 is realized between the lower end of the connection element 50 and the terminal portion 30' of the stabilizer bar 35 while the upper hinge 52 is seated into the seat 42' and is realized between the multipurpose bracket 10 and the upper end of the connection element 50.

According to the described embodiment, the connection element 50 comprises a pair of arms 50', 50' placed laterally with respect to the terminal portion 30 and the multipurpose bracket 10, therefore spaced apart along transversal direction, and hinged at respective terminal ends to hinges 51, 52.

If configured, the multipurpose bracket 10 further defines a third connection point 44 configured to house the support element 60. In particular, the third connection point 44 defines a seat 44'carried by the same protruding portion that defines seat 42' and configured to house the support element that may be represented by a straight rod extending parallel to transversal axis B. In particular, the straight rod may be fixed by interference of by threaded elements into the seat 44'.

In particular, the main plate 40 is fixed to the side member 5 outside with respect to the space transversally comprised between the side members 4, 5, i.e. towards the exterior of the vehicle. More preferably, the first and second connection points 41, 42 are spaced apart in longitudinal direction of axis A while the third connection point 44 is placed between these latter, and preferably more near to the second connection point 42. Moreover, it is noticed that the third connection point 44 is placed faced to the respective side member 5, while the first and second connection points 41, 42 are both placed beneath the side member 5. In particular, the third connection point 44 is realized vertically upper with respect to the first and second support points 41, 42, i.e. more distanced with respect to ground.

Moreover, the first support point 41 is vertically comprised between the third connection point 44 and the second connection point 42, i.e. the first support point 41 is vertically upper with respect to second support point 42.

According to the above optimized geometry, the main plate 41 of the multipurpose bracket 10 has a substantial U- shape wherein one leg (defining first connection point 41) is shorter with respect to the other (defining second connection point 42 and third connection point 44). In particular, it is noticed that the width along longitudinal axis A of such two legs is different, i.e. the leg defining the first connection point is wider with respect to the other.

As shown in figures 4 and 6, the mudguard 70 is configured to receive the support element 60 thereby fixing with respect to side member 50n its most rear portion. Other fixation points, in front portion, may be clearly provided.

The main plate 40 and the connection points 41, 42, 44 are preferably realized as one piece and in a metallic material such as cast iron.

The operation of the above described suspension system 1 is the following. During the motion of the vehicle the axle 2 follows the asperity of the road and may move with respect to the chassis 3 of the vehicle. In particular, at least part of the motion torque is imparted to the vehicle via the axle 2.

Such motions are dampened by suspension system 1, in particular:

• Vertical motions are dampened by dampers 11 and air bellows 8. Excessive vertical motions are stopped by stop means 27;

• Transversal and longitudinal motions are compensated by V-rod 21 and longitudinal rod; and

• Torque motions are compensated by stabilizer bar 30.

In view of the foregoing, the advantages of the above described suspension system according to the invention are apparent. The proposed suspension system 1, in particular the presence of multipurpose bracket 10, allows the mounting of the suspension 1 also in case of electric axle while maintaining good mechanical properties.

Furthermore, the proposed suspension system 1 is particularly compact and allows an easy assembly with standard components. Accordingly, costs are sensibly reduced.

Indeed, the use of single multipurpose bracket 10 allows to reduce the number of existing brackets for fixating the three described operational elements. Consequently to the reduction of the number of brackets, the number of fixation elements and machine working on the side members is equally reduced.

Since the multipurpose bracket 10 is realized in cast iron, thanks to its geometry, it is sufficiently stiff to support the connected elements without need of other reinforces .

Furthermore, with respect to known mudguard fixation method, the proposed one is particularly effective. Indeed, the use of a straight rod reduces the vibrations imparted by chassis to the mudguards.

Indeed, existing systems foresees the presence of a bend tube welded on a plate carried by the side member of the chassis. Such fixation transmits directly the vibrations to the mudguard whose useful life is reduced.

The fixation through the straight rod carried in seat defined by the multipurpose bracket reduces such vibrations.

It is clear that modifications can be made to the described suspension system which do not extend beyond the scope of protection defined by the claims. For example, presence position and shape of the elements of the suspension 1 may vary within the limit of the below claims.

Moreover, the suspension system 1 may be provided for any typology of axle, e.g. rear or front axles, standard or electrified axles.

The shown and described fixation means, hinges and connections may be vary and be substituted by equivalent means.