VEHICLE CHASSIS AND SUSPENSION SYSTEM

Abstract

A haulage vehicle has a suspension system providing a flexible connection between a vehicle chassis and at least one axle housing. The system has three longitudinal link members, a transverse link member, and a resilient member adjacent each end of the axle housing; all of which are connected at one end to the vehicle chassis and at an opposite end to the axle housing. The transverse link member substantially prevents movement of the axle housing in a transverse direction, and the three longitudinal link members are substantially aligned with the longitudinal axis of the chassis and spaced apart, providing a three-point connection between the chassis and axle housing. The three-point connection keeps the axle housing in a substantially transverse orientation relative to the chassis, preventing rotation of the axle housing about the longitudinal axis of the axle housing while allowing movement of the axle housing in the vertical plane.

Claims

1. A vehicle suspension system for providing a flexible connection between a vehicle chassis and at least one axle housing, the vehicle suspension system having three longitudinal link members, at least one transverse link member, and at least one resilient member situated adjacent each end of the axle housing; all of which are connected at one end to the vehicle chassis and at an opposite end to the axle housing, wherein the at least one transverse link member is configured to substantially prevent movement of the axle housing in a transverse direction, and the three longitudinal link members are each substantially aligned with the longitudinal axis of the chassis and are spaced apart to provide a three point connection between the chassis and the axle housing which is configured to keep the axle housing in a substantially transverse orientation relative to the chassis and to prevent rotation of the axle housing about the longitudinal axis of the axle housing while allowing movement of the axle housing in the vertical plane, and wherein movement of the axle housing in the vertical plane is limited by the resilient members which connect each end of the axle to the chassis.

2. A vehicle suspension system as claimed in claim 1, wherein the vehicle suspension system includes two resilient members at each end of the or each axle housing.

3. A vehicle suspension system as claimed in claim 2, wherein each of the two resilient members at each end of the or each axle housing is positioned on an opposite side of the axle housing to the other.

4. A vehicle suspension system as claimed in claim 1, wherein the connection of the resilient members to the or each axle housing is situated near or adjacent the lowest point of the or each axle housing in the vicinity of the connection.

5. A vehicle suspension system as claimed in claim 1, wherein a first of the three longitudinal links is connected to a left half of the axle housing, and a second of the three longitudinal links is connected to a right half of the axle housing.

6. A vehicle suspension system as claimed in claim 5, wherein a third of the three longitudinal links is connected to a mid section of the axle.

7. A vehicle suspension system as claimed in claim 5, wherein the first and the second longitudinal links are connected to points low on the axle housing and the third longitudinal link is connected to a point high on the axle housing.

8. A vehicle suspension system as claimed in claim 1, wherein each of the longitudinal links is substantially parallel to the others.

9. A vehicle suspension system as claimed in claim 5, wherein the first and the second longitudinal links are each connected to fixed struts which extend downwards from the main longitudinal chassis members.

10. A vehicle suspension system as claimed in claim 1, wherein the longitudinal and transverse links are connected to both the chassis and to the axle housing using pinned joints.

11. A vehicle suspension system as claimed in claim 1, wherein the resilient members include springs.

12. A vehicle suspension system as claimed in claim 1, wherein the resilient members include shock absorbers.

13. A vehicle suspension system for providing a flexible connection between a vehicle chassis and a forward axle, the chassis comprising two longitudinal beams, each longitudinal beam being stepped upwards as it passes over the axle, and the connection between the vehicle chassis and the axle comprising two longitudinal link members, two angled link members and two resilient members configured to allow movement of the axle in a substantially vertical direction only, the angled link members being oriented in a direction that is between a longitudinal direction and a transverse direction.

14. A vehicle suspension system as claimed in claim 13, wherein the angled link members are oriented in a direction that is between thirty and sixty degrees offset from the longitudinal direction.

15. A vehicle suspension system as claimed in claim 13, wherein the longitudinal link members are connected to a lower portion of the stepped longitudinal beams of the chassis.

16. A vehicle suspension system as claimed in claim 13, wherein the resilient members are connected to an upper portion of the stepped longitudinal beams of the chassis.

17. A vehicle suspension system as claimed in claim 13, wherein the longitudinal link members are connected to a lower portion of the axle.

18. A vehicle suspension system as claimed in claim 13, wherein the angled link members are connected to an upper portion of the axle.

19. A vehicle suspension system as claimed in claim 13, wherein the angled link members are connected to the axle at a location at or adjacent a centre section of the axle.

20. A vehicle incorporating at least one vehicle suspension system substantially as claimed in claim 19.

Description

DESCRIPTION

[0040] Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

[0041] FIG. 1 is a perspective view showing an underside of a vehicle suspension system and chassis according to the present invention,

[0042] FIG. 2 is an end elevation view of the vehicle suspension system,

[0043] FIG. 3 is a plan elevation view of the vehicle suspension system,

[0044] FIG. 4 is a side elevation view of the vehicle suspension system and chassis,

[0045] FIG. 5 is a perspective view showing an upper view of the vehicle suspension system and chassis,

[0046] FIG. 6 is an upper perspective view of the main components of a forward suspension system,

[0047] FIG. 7 is an upper perspective view of the main components of a rear suspension system,

[0048] FIG. 8 is a perspective view showing connection points on a forward end of the chassis, and

[0049] FIG. 9 is a perspective view showing connection points on an aft end of the chassis.

[0050] With reference to FIGS. 1 to 5, 7 and 9, a vehicle suspension system (11) according to the present invention will now be described. The vehicle suspension system (11) is designed for use on the rear axles of heavy haulage vehicles, and is designed to be rugged and durable for use on both unpaved and paved surfaces, while being relatively compact and low in weight.

[0051] The vehicle suspension system (11) provides a flexible connection between a vehicle chassis (13) and at least one rear axle housing (15). The vehicle suspension system (11) includes three longitudinal link members (17) and at least one transverse link member (19). The link members are each connected at one end to the vehicle chassis (13) and at an opposite end to the axle housing (15).

[0052] The vehicle suspension system (11) also includes two resilient members (21) situated adjacent each end of the axle housing (15). The resilient members (21) are in the form of telescopic shock absorbers which are connected at one end to the vehicle chassis (13) and at an opposite end to the axle housing (15).

[0053] The transverse link member (19) is configured to substantially prevent movement of the axle housing (15) in a transverse direction.

[0054] The three longitudinal link members (17) are each substantially aligned with the longitudinal axis of the chassis (13) and are spaced apart to provide a three point connection between the chassis (13) and the axle housing (15). This configuration of the three longitudinal link members (17) is configured to keep the axle housing (15) in a substantially transverse orientation relative to the chassis (13) and to prevent rotation of the axle housing (15) about its longitudinal axis. However, the configuration of the three longitudinal link members (17) still allows movement of the axle housing (15) in the vertical plane.

[0055] Movement of each end of the axle housing (15) in the vertical plane is limited by the resilient members (21) which connect each end of the axle (15) to the chassis (13). The resilient members (21) include shock absorbers and springs to support the weight of the loaded vehicle (23).

[0056] In this example, the vehicle (23) includes two rear axles (15), and each axle (15) has two resilient members (21) at each end. And at each end, one resilient member (21) is connected to axle housing (15) and the other resilient member (21) is connected to the other side of the axle housing (15). The connection of the resilient members (21) to the axle housings (15) is situated near or adjacent the lowest point of the axle housings (15) in the vicinity of the connection. Due to this configuration, the length of the resilient members (21) can be maximised, and the reaction loads experienced by the axle housing (15) from the resilient members (21) are balanced, minimising any twisting action caused by the resilient members (21) when bumps are encountered while travelling over rough terrain.

[0057] A first of the three longitudinal links (17) is connected to a left half of the axle housing (15), and a second of the three longitudinal links (17) is connected to a right half of the axle housing (15), both at points low on the axle housing (15). And a third of the three longitudinal links (17) is connected to a mid section of the axle (15), at a point high on the axle housing (15). All of the longitudinal links (17) are substantially parallel to the others. In this way the longitudinal links (17) provide a three point triangular linkage system between the axle housing (15) and the chassis (13), allowing vertical movement of the axle housing (15), while restricting rotation of the axle housing (15) about its own axis and about a vertical axis.

[0058] The first and the second longitudinal links (17) are each connected to the bottom end of fixed struts (25) which extend in a downwards direction from the main longitudinal chassis members (27). The fixed struts (25) are triangular in shape, with a base of the triangular shape connected to the main longitudinal chassis members (27) and with a connection to the longitudinal links (17) at the free apex of the triangular shape.

[0059] Each of the longitudinal and transverse links (17) and (19) are connected to both the chassis (13) and to the axle housing (15) using pinned joints which allow for limited pivoting movement.

[0060] FIG. 9 shows resilient member attachment lugs (29), longitudinal member attachment lugs (31) and a transverse member attachment lug (33), on an aft end of the chassis (13).

[0061] With reference to FIGS. 1 to 6, and 8, a vehicle suspension system (51) for providing a flexible connection between the vehicle chassis (13) and a forward axle (53) will now be described.

[0062] The vehicle chassis (13) includes two longitudinal beams (55). Each longitudinal beam (55) is stepped upwards as it passes over the forward axle (53).

[0063] The connection between the vehicle chassis (13) and the axle (53) includes two longitudinal link members (57) and two angled link members (59). The angled link members (59) are oriented in a direction that is between a longitudinal axis or direction and a transverse axis or direction of the vehicle chassis (13). It is envisaged that the angled link members (59) are ideally oriented in a direction that is between thirty and sixty degrees offset from the longitudinal axis of the vehicle chassis (13), and more preferably between forty and fifty degrees offset from the longitudinal axis of the vehicle chassis (13).

[0064] The connection between the vehicle chassis (13) and the axle (53) also includes two resilient members (61). The resilient members (61) include shock absorbers and springs to support the weight of the loaded vehicle (23).

[0065] The arrangement of the two longitudinal link members (57), the two angled link members (59) and the two resilient members (61) is designed to allow movement of the axle (53) in a substantially vertical direction only.

[0066] The longitudinal link members (57) and the angled link members (59) are connected to a lower portion of the stepped longitudinal beams (55) of the chassis (13). And the resilient members (61) are connected to an upper portion of the stepped longitudinal beams (55).

[0067] The longitudinal link members (57) are connected to a lower portion of the axle (53) and the angled link members (59) are connected to an upper portion of the axle (53). The angled link members (59) are connected to the axle at a location at or adjacent a centre section of the axle (53) and the longitudinal link members (57) are connected to the axle (53) at locations at or adjacent each end of the axle (53).

[0068] It can be seen in FIG. 8 that the connection between the longitudinal link members (57) and the longitudinal beams (57) of the chassis (13) is aligned with a lower flange (63) of the longitudinal beams (55). And the connection between the angled link members (59) and the longitudinal beams (55) is aligned with an upper flange (65) of the longitudinal beams (55).

[0069] As noted above, the aft suspension system (11) and the forward suspension system (51) are designed for use on a heavy haulage vehicle (23). Although not shown in the figures, heavy haulage vehicle (23) also includes wheels, a cab and a tip-tray. The heavy haulage vehicle (23) includes two rear axles (15) and each rear axle (15) is connected to the chassis (13) of the vehicle by a vehicle suspension system (11) as described above. The vehicle suspension system (11) of the forward of the two rear axles (15) is a mirror image of the vehicle suspension system (11) of the aft of the two rear axles (15).

[0070] The longitudinal links (17) of the forward-most rear axle (15) are connected to the rear face of the forward-most rear axle (15), and the longitudinal links (17) of the aft-most rear axle (15) are connected to the forward face of the aft-most rear axle (15). The first longitudinal link (17) of the forward-most rear axle (15) and the first longitudinal link (17) of the aft-most rear axle (15) are each connected to a first fixed strut (25) that extends downwards from one side of the chassis (13) of the vehicle (23), and the second longitudinal link (17) of the forward-most rear axle (15) and the second longitudinal link (17) of the aft-most rear axle (15) are each connected to a second fixed strut (25) that extends downwards from the opposite side of the chassis (13).

[0071] FIG. 8 shows resilient member attachment lugs (69), longitudinal member attachment lugs (71) and angled member attachment lugs (73), on a forward end of the chassis (13).

[0072] An engine (81) of the vehicle (23) is situated low and between the chassis beams (55), immediately aft of the attachment points of the forward vehicle suspension system (51). In this way the centre of gravity of the vehicle (23) is kept low, and there is a direct route for the drive train to the rear axles (15).

[0073] Variations

[0074] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

[0075] In the example described above, the vehicle suspension systems included metal spring style shock struts. It is envisaged that in an alternative configuration air springs could be used.

DEFINITIONS

[0076] Throughout this specification the word comprise and variations of that word, such as comprises and comprising, are not intended to exclude other additives, components, integers or steps.

[0077] Advantages

[0078] Thus it can be seen that at least the preferred form of the invention provides a vehicle suspension system in which the longitudinal link members are appropriately aligned to transfer the largely longitudinal acceleration and braking forces between the axle housings and the vehicle chassis, without picking up any appreciable side loads when the vehicle is travelling over rough terrain. This minimises the need for excessively large and therefore heavy suspension components.

[0079] In addition, the configuration of the suspension system provides sufficient length for the operation of the shock struts of the resilient members as well as strong and direct attachment to the underside of the vehicle chassis allowing efficient and secure load transfer when travelling over rough terrain while carrying a heavy payload.

[0080] The combination of the low centre of gravity of the vehicle and the compact and robust suspension systems provides a multi-role haulage vehicle that can carry heavy payloads both over rough terrain and also at speed over long distances over paved surfaces.