Improved suspension system for heavy vehicles

Abstract

Suspension system (1) for heavy vehicles, configured to connect an axle (2) of a heavy vehicle to a chassis (3), the axle (2) extending along a transverse axis (B) with respect to a longitudinal axis (A) of the vehicle, the suspension system comprising, in addition to other elements, a stabilizer bar (35) operatively interposed between a metal beam (7) and the chassis (3), wherein the stabilizer bar (35) is placed below the axle (2) and the metal beam (7), a straight portion (35') of the bar (35) being supported by the metal beam (7) via support means (36), and wherein a terminal portion (35") of the stabilizer bar (35) is supported in a free rotation manner by a front hanger (32) via a connection assembly (38).

Description

[0001] Cross-reference to related applications

[0002] This patent application claims priority to Italian patent application no. 102020000025021, filed on October 22, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to suspension systems for heavy vehicles, and more particularly to suspension systems for heavy vehicles equipped with electronic traction devices. Background Technology

[0004] Heavy-duty vehicles, such as road transport vehicles and trucks, are increasingly being electrified to reduce their pollution emissions. In particular, these vehicles can be hybrid or fully electric vehicles.

[0005] In particular, electrified vehicles include at least one electrically driven rear axle, i.e., a rear drive axle equipped with a motor, such as a motor / generator, which is configured to apply torque to the axle to allow movement of the axle or to charge the vehicle's battery module when the vehicle is braking.

[0006] Such battery modules are typically placed near the motor on the axle of an electric vehicle in order to provide energy exchange with the motor in an efficient manner.

[0007] However, as is known, the vehicle's axles are connected to the vehicle's chassis via a suspension system configured to dampen forces acting between the road and the chassis.

[0008] If the vehicle is equipped with an electric axle as described above, the presence of the battery increases obstacles around the chassis.

[0009] Therefore, due to the presence of electric axles, known suspension systems for heavy vehicles are unsuitable.

[0010] Therefore, there is a need to provide a suspension system with a new arrangement that can be mounted to the electric vehicle axle and provides at least the same mechanical performance as known suspension systems.

[0011] The purpose of this invention is to meet the above-mentioned needs in a compact, optimized and cost-effective manner. Summary of the Invention

[0012] The aforementioned objective is achieved by the suspension system and vehicle as claimed in the appended independent claims.

[0013] Preferred embodiments of the present invention are implemented according to claims that are dependent on or related to the above independent claims. Attached Figure Description

[0014] To better understand the present invention, preferred embodiments are described below with reference to the accompanying drawings by way of non-limiting examples, in which:

[0015] · Figure 1 This is a perspective view of the suspension system according to the present invention;

[0016] · Figure 2 yes Figure 1 A bottom view of the suspension system;

[0017] · Figure 3 yes Figure 1 Side view of the suspension system;

[0018] · Figure 4 and Figure 5 These are, respectively, a bottom view and a top view of a portion of the suspension system according to the present invention;

[0019] · Figure 6 yes Figure 4 and Figure 5 A side view of the portion of the suspension system;

[0020] · Figure 7 and Figure 8 This is a corresponding enlarged perspective view of the connection between the components of the suspension system according to the present invention. Detailed Implementation

[0021] Figure 1 A suspension system 1 for connecting the axle 2 of a heavy vehicle to the chassis 3 of the heavy vehicle is disclosed. As is known per se, the chassis 3 includes a pair of side members 4, 5 that extend along the longitudinal axis A of the vehicle and are laterally spaced apart.

[0022] It should be noted that the suspension system 1 can be configured to include a front axle (not shown) and a single rear axle 2 (see [reference]). Figure 4 , Figure 5 and Figure 6 ) or two rear axles 2 ( Figure 1 , Figure 2 , Figure 3 ) work vehicles.

[0023] In the presence of two rear axles 2, the second rear axle 2 is positioned in the forward position relative to the first rear axle 2 along axis A.

[0024] Clearly, each rear axle between the first rear axle 2 and the second rear axle 2 can be configured as a tag axle 2” or an electrically driven axle 2’, and in particular, at least one of the two rear axles 2 can be configured as an electrically driven axle 2’.

[0025] The electric drive axle 2' is equipped with a motor powered by at least one battery module (not shown) to provide torque to the wheel carried by the electric drive axle 2', or to receive electrical energy generated by the motor when the vehicle is braking. Due to the presence of such a motor, the electric drive axle 2' has a greater range of extension forward and backward relative to the standard axle 2' in the space laterally included between the side members 4 and 5 along axis A.

[0026] Therefore, first and second suspension systems 1 are respectively installed between chassis 3 and the first rear axle 2 and between chassis 3 and the second rear axle 2.

[0027] Since the second suspension system is equivalent to the first suspension system, only the first suspension system 1 will be referred to. The first suspension system 1 includes a left side portion 1” and a right side portion 1’. Since the left side portion 1” and the right side portion 1’ are symmetrical and identical with respect to the longitudinal axis A, for the sake of simplicity, only the right side portion 1’ will be described.

[0028] Reference Figure 2 and Figure 6 The suspension system 1 includes a metal beam 7, i.e., a spring beam, which includes a front end portion 7a and a rear end portion 7b extending along a longitudinal axis A. As described below, the metal beam 7 is connected to the axle 2 in an intermediate portion 7c that is longitudinally located between the front end portion 7a and the rear end portion 7b.

[0029] Each of the front end portion 7a and the rear end portion 7b is connected to the chassis 3, i.e., to the side member 5, via an air spring, such as an air bellows 8, which is placed vertically between the chassis 3 and the metal beam 7.

[0030] Specifically, the air bellows 8 includes an upper portion 8a and a lower portion 8b. The upper portion 8a is configured to be connected to the chassis 3, for example, via a bracket 9, and the lower portion 8b is connected, for example, via a threaded element to a corresponding front or rear end portion 7a or rear end portion 7b. As is known per se, each air bellows 8 includes an air bladder 8c carried between the upper portion 8a and the lower portion 8b, and is configured to contain pressurized air to dampen relative movement between the upper portion 8a and the lower portion 8b.

[0031] The metal beam 7 is also connected to the chassis 3, i.e., to the side member 5, via a damper 11 placed therebetween along the aforementioned vertical direction. In particular, the damper 11 is substantially vertical relative to the side member 5 / ground.

[0032] Preferably, the damper 11 is a hydraulic damper, i.e., a hydraulic cylinder, which includes a housing 11a carried by the side member 5 and a stem 11b connected to the metal beam 7. As is known per se, the stem 11b is configured to move within the housing 11a against the action of fluid contained in the housing 11a, in order to suppress relative movement between the side member 5 and the metal beam 7.

[0033] The stem portion 11b is connected to the metal beam 7 in a portion contained between the intermediate portion 7c and either the front terminal portion 7a or the rear terminal portion 7b, as described below.

[0034] Specifically, the stem-like portion 11b is connected to the metal beam 7 via a hinged connector 12, which is configured to allow the terminal portion of the stem-like portion 11b to rotate about an axis parallel to the transverse axis B, which is the longitudinal axis of the axle 2. The housing 11a is alternatively connected to the side member 5 via a hinged connector 13, which is configured to allow the terminal portion of the housing 11a to rotate about an axis parallel to the longitudinal axis A.

[0035] The metal beam 7 is connected to the corresponding axle 2 via a connecting assembly 15, which preferably includes at least a plate 16, which is vertically positioned between the axle 2 and the middle portion 7c of the metal beam 7.

[0036] Plate 16 defines: a top portion configured to engage with the outer surface of the axle 2; and a lower portion configured to engage with the outer surface of the metal beam 7.

[0037] The connecting assembly 15 also includes a retaining device 17 configured to apply a compressive force between the axle 2, the plate 16 and the metal beam 7 so as to hold the axle 2, the plate 16 and the metal beam 7 together by friction.

[0038] Specifically, the retaining device 17 may include two U-shaped supports 18, each U-shaped support 18 being provided with: threaded end ends configured to pass through the middle portion 7c of the metal beam 7; and threaded elements configured to cooperate with these threaded end ends to apply a compressive force between the elements.

[0039] The suspension system 1 also includes a lateral retaining element 20 configured to support lateral movement between the axle 2 and the chassis 3 but allow vertical movement between these elements.

[0040] Specifically, the lateral retaining element 20 includes a V-shaped rod 21, which is provided with a first arm portion 21' and a second arm portion 21'". The first arm portion 21' and the second arm portion 21' are each provided with a first part and a second part. The first parts are stably connected together, while the second parts are spaced apart in the lateral direction starting from the connection of the first parts.

[0041] Therefore, the first arm portion 21' and the second arm portion 21" are inclined relative to the longitudinal axis in the horizontal plane, such that each of the second portions of the first arm portion and the second arm portion is closer to the corresponding side member 4, 5. More specifically, the first arm portion 21' and the second arm portion 21" are symmetrical with respect to the longitudinal axis A.

[0042] Advantageously, the first arm portion 21' and the second arm portion 21" are implemented as a single piece. The first portion of the first arm portion and the first portion of the second arm portion are connected to the axle 2 via a hinged connector 22, which allows such a first portion to rotate about an axis parallel to the transverse axis B. More preferably, the first portion is connected to the axle 2 in its upper portion, and even more preferably, it is connected to the axle 2 via a flange 23 carried by the axle 2.

[0043] The second portion of the first arm 21' and the second portion of the second arm 21" are connected to the chassis 3 via corresponding hinged connectors 24. In the disclosed embodiment, the hinged connectors 24 are implemented by flange elements 25, which are supported in a manner that allows them to be suspended from the corresponding side members 4, 5. Such flange elements 25 are fixed to the corresponding side members 4, 5 via fixing elements such as threaded elements.

[0044] The suspension system 1 also includes a stop device 27 configured to prevent excessive vertical movement of the axle 2 relative to the chassis 3. In particular, this stop device 27 includes a flange 28 fixedly supported by the chassis 3, for example by an intermediate element (not shown) supported by side members 4 and 5, and the flange 28 is configured to engage with the outer surface of the axle 2 when the movement of the axle 2 exceeds a predetermined height.

[0045] Advantageously, the suspension system 1 includes a pair of stop devices 27, which are housed in a space laterally included by the side members 4 and 5 and are arranged symmetrically with respect to the longitudinal axis A. Preferably, the flange 28 may be provided with a rubber damper to avoid direct metal-to-metal contact between the axle 2 and the flange 28.

[0046] The suspension system 1 also includes a longitudinal retaining element 30, which is configured to support longitudinal movement between the axle 2 and the chassis 3 but allows vertical movement between the axle 2 and the chassis 3.

[0047] Specifically, the longitudinal retaining element 30 includes a rod-shaped member 31 that connects the axle 2 to the chassis 3 via a metal beam 7. In particular, the rod-shaped member 31 connects the axle 2 to the front suspension 32, which is fixedly supported by the side members 4 and 5.

[0048] More specifically, the rod-shaped member 31 includes a first terminal portion 31a and a second terminal portion 31b along axis A, and an intermediate portion 31c contained between the first terminal portion 31a and the second terminal portion 31b.

[0049] The first terminal portion 31a is connected to the front hanger 32 via a hinge 33, and the second terminal portion 31b is connected to the metal beam 7 via another hinge 33. The two hinges 33 are configured to allow movement about an axis parallel to the lateral axis B of the respective terminal portions 31a, 31b. It should be noted (see...) Figure 2 The rod-shaped member 31 is placed entirely on the lateral outer side relative to the space contained in the side members 4 and 5.

[0050] The front hanger 32 includes an upper portion 32' and a lower portion 32'. The upper portion 32' is configured to allow the front hanger 32 to be fixed to the corresponding side members 4, 5, and the lower portion 32' is configured to allow the rod-shaped member 31 to be connected to the corresponding side members 4, 5.

[0051] The upper portion 32' defines a plurality of holes 34 configured to allow the front hanger 32 to be secured to the side members 4, 5, and the upper portion 32' has a greater longitudinal extension range relative to the lower portion 32". In other words, the intermediate portion 32"' connecting the upper portion 32' and the lower portion 32" has a tapered cross section along the longitudinal axis A.

[0052] Preferably, the hinge 33 between the rod 31 and the lower portion 32” of the front hanger 32 is implemented between a pair of terminal legs that extend from the lower portion 32” and are spaced apart, thereby defining a space for accommodating the rod 31 and providing support for the hinge 33.

[0053] The suspension system 1 also includes a stabilizer bar 35, which is configured to dampen possible torques acting between the axle 2 and the chassis 3.

[0054] The stabilizer bar 35 basically includes (such as) Figure 4 (Best shown in the diagram) a generally straight portion 35' and a pair of terminal portions 35'. The terminal portions 35' are connected to the straight portion 35' via corresponding curved portions 35''.

[0055] The stabilizer bar 35 is positioned below the axle 2 and the metal beam 7. Advantageously, the straight portion 35' is supported by the metal beam 7, and the end portion is supported by the front suspension 32.

[0056] Furthermore, the terminal portion 35” extends substantially perpendicularly to the straight portion 35’, that is, along the longitudinal axis A, and the terminal portions 35” are all placed on the same side relative to the straight portion 35’.

[0057] Therefore, the stabilizer bar 35 defines a generally U-shaped path in the horizontal plane, wherein the straight portion 35' is placed between the air bellows 8 and the corresponding axle 2.

[0058] The curved portion 35”’ is positioned externally relative to the side members 4, 5 (see Figure 2 This allows the curved portion 35”' to rotate without interfering with the electric vehicle axle 2” or any other components attached to the side members 4, 5, such as the battery module.

[0059] More specifically, the straight portion 35' is supported by the metal beam 7 via the support device 36. In particular, the support device 36 includes a first half 36' and a second half 36'". The first half 36' is fixedly supported by the middle portion of the metal beam 7, preferably as a single piece, and the second half 36' can be selectively fixed to the first half 36' to allow for the installation and removal of the stabilizer bar 35.

[0060] More preferably, both the first half 36' and the second half 36" are made of a metallic material. The support device 36 may include two half-shells (not shown in detail) made of a polymer material such as rubber, which are fixed to the respective half-shells 36', 36" by fixing these respective half-shells together.

[0061] Specifically, the support device 36 consists of two devices located at the end of the straight portion 35', i.e., near the curved portion 35", and configured to allow the stabilizer bar 35 to rotate about an axis parallel to the transverse axis B.

[0062] Each of the terminal portions 35” is connected to the chassis 3 via a connecting assembly 38, which is configured to allow movable connection, specifically rotational movement about an axis parallel to the transverse axis B.

[0063] More specifically, the connecting assembly 38 includes a connecting element 40, which is provided with a lower end connected to the terminal portion via a hinge 39 and an upper end connected to the chassis 3 via another hinge 39. Both hinges 39 are configured to allow rotation about an axis parallel to the lateral axis B.

[0064] Preferably, the hinge 39 between the upper end of the connecting element 40 and the chassis 3 is realized between this upper end and the front hanger 32. More specifically, the front hanger 32 defines a support portion 41 that extends cantileveredly in the space included between the side members 4 and 5.

[0065] Specifically, the support portion 41 extends from the middle portion 32”' of the front hanger 32 to a flange near the upper portion 32’. Preferably, the support portion 41 and the front hanger 32 are implemented as a single piece, and the connecting element can be detachably installed to the front hanger 32.

[0066] Preferably, the connecting element 40 includes a pair of arms 40', 40" which are placed laterally relative to the terminal portion 35" and thus spaced apart in the lateral direction, and are hinged to the hinge 39 at the respective terminal ends.

[0067] In the described dual rear axle configuration, the front suspension 32 is shared and allows for the connection of the longitudinal bars 31 of the two suspension systems 1 and the connection of the stabilizer bars 35.

[0068] Furthermore, in the two-axle configuration, two other possibilities can be envisioned, in which the first rear axle 2 is a drive axle and the second rear axle 2 is a support axle, such as... Figure 1 As shown, and wherein both the first rear axle 2 and the second rear axle 2 are drive axles, as... Figure 2 and Figure 3 As shown in the figure.

[0069] The difference between the two implementations lies in the position of the damper 11 and the position of the opening of the U-shaped stabilizer bar 35.

[0070] In fact, Figure 1 In this configuration, the dampers 11 are all positioned at the rear relative to the corresponding axle 2, and the U-shaped stabilizer bars 35 are all open towards the front of the vehicle, meaning the U-shaped stabilizer bars 35 have the same arrangement. In this configuration, a single stabilizer bar 35 is supported by a central common front suspension 32, while the other stabilizer bar is directly connected to the portion fixedly supported by the side elements 3, 4.

[0071] Alternatively, in Figure 2 In this configuration, the damper 11 is positioned externally relative to the corresponding axle 2, i.e., in a rear position relative to the first rear axle and in a front position relative to the second rear axle along axis A. In this configuration, the stabilizer bars 35 are positioned such that they open in opposite directions, i.e., the stabilizer bars 35 are symmetrically opposite each other with respect to the lateral axis B. In other words, the openings of the U-shaped cross-sections of the stabilizer bars face each other. In this configuration, a central common front suspension 32 supports both stabilizer bars 35.

[0072] The operation of the suspension system 1 described above is as follows.

[0073] During the movement of the vehicle, at least one axle 2 follows the unevenness of the road and can move relative to the vehicle's chassis 3. In particular, at least a portion of the kinetic torque is applied to the vehicle via the electric axle 2'.

[0074] These movements are damped by suspension system 1, specifically:

[0075] Vertical movement is suppressed by damper 11 and air spring 8. Excessive vertical movement is stopped by stop device 27;

[0076] Lateral and longitudinal movements are compensated by V-shaped rod 21 and longitudinal rod 31; and

[0077] Torque motion is compensated by stabilizer bar 35.

[0078] In view of the foregoing, the advantages of the suspension system described above according to the present invention are obvious.

[0079] The proposed suspension system 1, especially the position of the stabilizer bar 35, allows the suspension 1 to be installed even with the electric axle 2”, while maintaining good mechanical performance.

[0080] Furthermore, the proposed suspension system 1 is particularly compact. Additionally, the presence of the connecting assembly 38 allows the stabilizer bar 35 to be connected to the generally standard front suspension 32.

[0081] The special arrangement of the stabilizer bar 35 between the front hanger 32 and the metal beam 7 allows for the use of a standard one-piece stabilizer bar 35.

[0082] Similarly, the rod-shaped member 31 and the V-shaped member 21 are standard components, and the support / hinge is of standard type. Therefore, the suspension system 1 is particularly inexpensive.

[0083] In addition, the support 36 allows for easy installation of the stabilizer bar 35 and provides good damping during the rotation of the stabilizer bar 35.

[0084] As shown, the proposed suspension system 1 can be used in different vehicle configurations, namely, single-drive-drive or drive-support or support-drive configurations, dual-drive-drive or drive-support or support-drive configurations. Therefore, the proposed suspension system allows for economies of scale because it can be used in different vehicle configurations.

[0085] It is evident that modifications can be made to the described suspension system without exceeding the scope of protection defined by the claims.

[0086] For example, the location and shape of the components of suspension 1 can vary within the limitations of the appended claims.

[0087] In addition, the suspension system 1 can be configured for the following front or rear axles: the front or rear axle is configured as a drive axle or a support axle or as a standard axle and an electric axle.

[0088] The fixing devices, hinges, and connectors shown and described may vary and be replaced by equivalent devices.

Claims

1. A suspension system (1) for a heavy-duty vehicle, the suspension system (1) being configured to connect an axle (2) of the heavy-duty vehicle to a chassis (3), the axle (2) extending along a lateral axis (B) relative to a longitudinal axis (A) of the vehicle, the suspension system comprising: • Metal beam (7), the metal beam (7) includes a front end portion (7a) and a rear end portion (7b) along the longitudinal axis (A), and an intermediate portion (7c) contained between the front end portion (7a) and the rear end portion (7b); • A pair of air springs (8) operatively positioned between the front end portion (7a) and the rear end portion (7b) and the chassis (3); • A damper (11), which is operatively positioned between the intermediate portion (7c) and the chassis (3); • A longitudinal retaining element (30) operatively positioned between the metal beam (7) and the front hanger (32), which is fixedly supported by the chassis (3); • A lateral retaining element (20), which is operatively positioned between the axle (2) and the chassis (3); and • A stabilizer bar (35), which is operatively positioned between the metal beam (7) and the chassis (3), The stabilizer bar (35) is positioned below the axle (2) and the metal beam (7), and The stabilizer bar (35) includes a straight portion (35') and a pair of terminal portions (35"), the straight portion (35') being connected to the metal beam (7), and the pair of terminal portions (35") extending from the straight portion (35') and being connected to the front hanger (32). The straight portion (35') is supported by the metal beam (7) via a support device (36), and each of the two terminal portions (35") is supported by the front hanger (32) in a rotatable manner via a connecting assembly (38).

2. The suspension system according to claim 1, wherein, The support device (36) includes: a first half (36') supported by the metal beam (7); and a second half (36") configured to connect to the first half (36') to accommodate the straight portion (35'), thereby allowing the straight portion (35') to rotate about an axis parallel to the transverse axis (B).

3. The suspension system according to claim 2, wherein, The support device (36) includes a polymer element disposed between the first half (36') and the second half (36") and the straight portion (35').

4. The suspension system according to claim 1, wherein, The connecting assembly (38) includes a connecting element (40) having opposite ends that are respectively hinged to the front hanger (32) and the terminal portion (35”) of the stabilizer bar (35) via a hinge (39).

5. The suspension system according to claim 1, wherein, The terminal portion (35) is connected to the straight portion (35') via a curved portion (35”').

6. The suspension system according to claim 1, wherein, The air spring (8) includes an air bellows, which is provided with an upper portion and a lower portion that are correspondingly fixed to the chassis (3) and the metal beam (7).

7. The suspension system according to claim 1, wherein, The damper (11) includes a hydraulic cylinder, the end of which is hinged to the chassis (3) and the metal beam (7) via corresponding hinges (12, 13).

8. The suspension system according to claim 1, wherein, The intermediate portion (7c) is connected to the axle (2) via a connecting assembly (15), the connecting assembly (15) including a plate (16) and a retaining device (17), the plate (16) being vertically positioned between the axle (2) and the metal beam (7), and the retaining device (17) being configured to provide compressive force between the axle (2), the plate (16) and the metal beam (7).

9. The suspension system according to claim 1, comprising a stop device (27) supported by the chassis (3) and configured to restrict vertical movement of the axle (2).

10. The suspension system according to claim 1, wherein, The longitudinal retaining element (30) includes a longitudinal rod (31) which is hinged at its end between the metal beam (7) and the front hanger (32).

11. The suspension system according to claim 1, wherein, The lateral retaining element (20) includes a V-shaped rod (21), which includes a first arm (21') and a second arm (21"), the first arm (21') and the second arm (21") including: a first end, the first end being joined together and hinged to the chassis (3); and a second end, the second end being each hinged to the top of the axle (2), the hinge allowing the respective end to move about an axis parallel to the lateral axis (B).

12. The suspension system according to claim 11, wherein, The second end of the first arm (21') and the second end of the second arm (21") are hinged to the flange (25) carried by the chassis (3).

13. The suspension system according to claim 7, wherein, The damper (11) is generally vertical.

14. A vehicle comprising a rear electric drive axle (2) and a suspension system (1) for the rear electric drive axle (2) according to any one of claims 1 to 13.

15. A vehicle comprising a first rear axle (2') and a second rear axle (2"), the vehicle comprising a first suspension system (1') for the first rear axle (2') and a second suspension system (1") for the second rear axle, the first suspension system (1') and the second suspension system (1") being configured as a suspension system (1) according to any one of claims 1 to 13, the vehicle comprising a suspension (32) shared for the first suspension system (1') and the second suspension system (1"), at least one of the first rear axle (2') and the second rear axle (2") being an electrically driven axle.

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