IES83366Y1 - A trailing arm suspension assembly - Google Patents

Description

A Trailing arm suspension assembly This invention relates to a leading or trailing arm suspension assembly in particular for armoured vehicles.

In wheeled armoured vehicles the space claim of the suspension system is a critical factor when seeking to maximise the usable interior volume of the vehicle. Typically a wheel well incorporating the suspension system and wheel is built into the vehicle and this intrudes into the interior space of the vehicle reducing the interior volume and causing an obstruction. Further, in conventional suspension systems spring mounts, bump and rebound stops and control arms are typically mounted on the hull of the vehicle as separate elements thus requiring accurate positioning of these locations on the hull to maintain the correct relationship of the various suspension elements to each other. This presents problems in the manufacture of such vehicles.

The present invention is directed towards overcoming these problems.

It is an object of the present invention to provide a suspension system which greatly reduces the intrusion of the suspension elements into the armoured hull thus maximising usable internal space in the vehicle.

According to the invention there is provided a leading or trailing arm suspension assembly including a suspension arm having an outer end and an inner end, the outer end for connection to a wheel or track support, the inner end being pivotally mounted on a support and connected to a spring means which opposes pivotal movement of the suspension arm away from a neutral position. Preferably a pivot axis about which the suspension arm rotates lies beneath the line of action of the spring means.

In another embodiment when the suspension arm is in the neutral position the suspension arm is supported either in a substantially horizontal position or the suspension arm inclines upwardly from the inner end to the outer end of the suspension arm.

In a preferred embodiment the spring means is supported in a substantially horizontal orientation. This provides for a very compact assembly.

In a further embodiment the inner end of the suspension arm is connected to a lever arm which in turn acts on the spring means.

In a particularly preferred embodiment the assembly forms a module having a sealed support housing within which the spring and lever arm are mounted, the lever arm being connected to the suspension arm by a pivot shaft which projects through an associated opening in a side wall of the housing, a seal being mounted in said opening about the shaft to seal between the housing and the shaft. in another embodiment the housing has horizontal connector flanges, plates or the like for connection to an underside of a chassis member or vehicle body.

In another embodiment the housing has means for reacting bump and rebound forces within the housing. in a further embodiment the lever arm has a rebound stop which is engagable against an inner side wall of the housing.

In another embodiment a bearing is mounted between the spring means and an inner side wall of the housing to transmit bump forces to the housing.

In a particularly preferred embodiment the suspension assembly includes a pair of in- line suspension arms, namely a forward suspension arm and a reanrvard suspension arm, the spring means for the arms being supported in a horizontal juxtaposed position. Preferably the spring means and the lever arms associated with each of the suspension arms are mounted in a common housing.

The invention will be more clearly understood by the following description of some embodiments thereof given by way of example only, with reference to the accompanying drawings, in which; Fig. 1 is a perspective view of a trailing arm suspension assembly according to the invention; Fig. 2 is an end elevational view of the assembly; Fig. 3 is a sectional elevational view taken along the line 111-111 of Fig. 2; Fig. 4 is a plan view of the assembly; Fig. 5 is a sectional view taken along the line V-V of Fig. 4; Fig. 6 is a sectional view taken along the line VI-VI of Fig. 4; Fig. 7 is an elevational view of the assembly; Fig. 8 is a sectional view taken along the line VIH-VIII of Fig. 7; Figs. 9 to 11 are detail sectional views of portion of the assembly; Fig. 12 is an elevation view of the assembly carrying a pair of wheels; Fig. 13 is an end elevational view showing a pair of the assemblies in position for connection to a vehicle body; Fig. 14 is a plan view of the pair of assemblies shown in Fig. 13; and Fig. 15 is a detail plan view of portion of the assembly.

Referring to the drawings there is illustrated a trailing arm suspension assembly according to the invention indicated generally by the reference numeral 1. The assembly 1 is in this case in the form of a two wheel station module. It will be appreciated however that a single wheel station module could alternatively be provided. A pair of suspension arms, namely a forward suspension arm 2 and a rear suspension arm 3 are pivotally mounted on a housing 4 containing spring means 5, 6 associated with each of the arms 2, 3 respectively . Each suspension arm 2, 3 has an outer end 8 upon which are mounted wheel hub assemblies 9. In the illustrated embodiment the wheel hubs 9 are non-steering. It will be appreciated however that in other embodiments means may be provided for steering the hubs 9. An inner end of each suspension arm 2, 3 is connected by a pivot shaft 11 with an associated lever arm 12 mounted within the housing 4. An upper end of the lever arm 12 is connected to a spring element which in this case comprises a hydrostrut 14 which extends between the lever arm 12 and a side wall of the housing 4.

Each pivot shaft 11 passes through an opening in a side wall of the housing 4.

A seal is mounted in said opening about the shaft 11 to seal between the housing 4 and the shaft 11.

The lever arm 12 is provided with an resilient rebound stop 16 at an upper end of the lever arm 12. This rebound stop 16 is engagable against an associated striking plate 17 on an inside face of a side wall of the housing 4.

A bearing 18 is mounted between the upper end of the lever arm 12 and an inner end 19 of the hydrostrut 14. A second bearing 20 is mounted between an outer end 21 of the hydrostrut 14 and an inner side wall of the housing 4 to transmit bump forces to the housing 4.

It will be noted that a pivot axis X about which each suspension arm 2, 3 rotates lies beneath the line of action Y of the hydrostrut 14 spring means.

It will also be noted that the pivot shaft 11, lever arm 12 and hydrostrut assemblies associated with each of the suspension arms 2, 3 are mounted side by side which provides a compact configuration. The hydrostruts 14 are supported in a substantially horizontal orientation.

In the illustrated embodiment the spring element is a hydrostrut 14 but in alternative embodiments various other spring media such as coil spring, rubber or any suitable elastic medium may be used. The mechanical rebound stop 16 reacts all the rebound forces directly on the housing 4 and likewise all the suspension bump forces are reacted directly into the housing 4 through the second bearing 20 mounted between the hydrostrut 14 and the housing 4.

Both of the bearings 18, 20 allow pivoting movement at each end of the hydrostrut 14. it will be noted that the complete assembly of moving parts are contained within the housing 4 and so are protected from dust, mud and mechanical impact. As the suspension and its force reaction elements are completely contained within the housing 4 the requirement for machining of the vehicle hull or accurate location of individual elements of a suspension system of the hull is eliminated.

Horizontal mounting flanges are provided on the housing 4 comprising an inner mounting flange 30 and an outer mounting flange 31. The outer mounting flange 31 has a central pivot hole 32 on either side of which mounting slots 33 are provided. These mounting slots 33 are somewhat elongated and are for reception of undersize mounting bolts for attachment of the assembly 1 to an underside of a vehicle allowing some adjustment in a horizontal plane. The inner mounting flange 30 has a number of mounting slots 34 which are elongated and arranged on a radius relative to the pivot hole 32. Thus the pivot hole 32 can be engaged with a spiggot or pivot pin on the underside of the vehicle and the whole assembly can be pivoted about the pivot pin swinging about a vertical axis through the pivot pin for correct alignment of the assembly 1 on the vehicle body. Once in alignment mounting bolts engage through the slots 33, 34 to securely bolt the assembly in position on the vehicle body.

It will be appreciated that the invention provides a suspension assembly of compact construction which can be mounted to an underside of the vehicle to minimise or eliminate intrusion into the interior volume of the vehicle. The modular assemblies are easy to fit and align on the vehicle body and require only one mounting point on the armoured hull. All of the interconnected moving elements and bearings are contained within a sealed housing. Also, all the bump and rebound forces are reacted within the assembly. While the inclusion of bump stops and rebound stops within the housing is desirable it is envisaged that in some configurations these may be omitted from the housing if desired. it is advantageous that the front suspension arm 2 rises between the inner end 10 and outer end 8. When the vehicle hits a bump the front leading arm with wheel will rise and move rearwards relieving the loads.

It will be noted also that the compact arrangement of the assembly 1 allows clearance for delivery of a drive shaft to the hub assemblies 9 if required.

With the twin suspension arm arrangement illustrated the suspension has zero net average torque applied to the hull mounting because the suspension arms produce opposite and on average equal torques.

Regarding the provision of a drive for the wheels this can be done in a number of different ways. For example a drive train may be fed through the suspension arm. Alternatively an electric motor could be provided in the hub and cabling and a cooling system delivered through the suspension arm through the electric motor.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims (1)

1.CLAIMS A leading or trailing arm suspension assembly including a pair of in-line suspension arms, namely a fonrvard suspension arm and a rear suspension arm, each suspension am having an outer end and an inner end, the outer end for connection to a wheel or track support, the inner end being pivotally mounted on a support and connected to a spring means which opposes pivotal movement of the suspension am away from a neutral position, a pivot axis about which the suspension arm rotates lying beneath the line of action of the spring means, and the spring means for the suspension amis being supported in a horizontal juxtaposed position. A suspension assembty as claimed in claim 1 wherein when the suspension arm is in the neutral position the suspension arm is supported either in a substantially horizontal position or the suspension arm inclines upwardly from the inner end to the outer end of the suspension arm, the spring means is supported in a substantially horizontal orientation, the inner end of the suspension arm is connected to a lever arm which in tum acts on the spring means, the spring means and the lever arms associated with each of the suspension arms being mounted in a common housing. A suspension assembly as claimed in claim 2 wherein the housing has horizontal mounting flanges, plates or the like for connection to an underside of a chassis member or vehicle body. A suspension assembly as claimed in any preceding claim wherein the assembly fomis a module having a sealed support housing within which each spring and lever arm are mounted, the lever arm being connected to the suspension am by a pivot shaft which projects through an associated opening in aside wall of the housing, a seal being mounted in said opening about the shaft to seal between the housing and the shaft. A suspension assembly substantially as hereinbefore described with reference to the accompanying drawings.