GB2394699A

GB2394699A - Amphibious vehicle suspension arrangement

Info

Publication number: GB2394699A
Application number: GB0225493A
Authority: GB
Inventors: Alan Timothy Gibbs
Original assignee: Gibbs Technologies Ltd
Current assignee: Gibbs Technologies Ltd
Priority date: 2002-11-01
Filing date: 2002-11-01
Publication date: 2004-05-05
Also published as: GB0225493D0; AU2003301752A1; WO2004039613A1

Abstract

An amphibious vehicle 1 has a body 3, retractable road wheels 12 and 13 mounted to the body and arranged to be moved from a lower position to an upper position. At least one of the road wheels having a wheel suspension 14 and 15 which comprises a suspension member 20 having a bearing 24 for supporting the wheel. The suspension member being connected to the body by at least one upper link 28 and 30 and one lower link 34 and 36, with the bearing being forward, of any connection of the or each link with the vehicle body, in relation to the longitudinal axis of the body. This arrangement may allow the vehicle engine 4 to be mounted close to the rear drive shafts 10 to give suitable weight distribution for the vehicle to plane. The arrangement may be applied to front and/or non-driven wheels. A hydraulic suspension strut 42 may be used to move the suspension, with said strut acting as an upper suspension link.

Description

Amphibious Vehicle Suspension The present invention relates to an

unphibiow vehicle having retractable road wheels each having a wheel ewpension.

5 Such a vehicle i. shown in US 5,531,179 (Roycroft et al). Id order to improve the routine and road perfiomance, it has been proposed to move the engine slighdy forward; and to align the engine transvmoly as shown diagrammatically in Figure 3 of PCT/GB 01/03493 (Pub. No. WO 02/14092). Such a conformation however results in Latin problems, in that the outer ends of the engine block we very c1080 to the suspension 10 mountings An amphibious vehicle according to die invention has a body, retractable road wheels mounted to the body and Winged to be moved freon a lower road engaging position in a land mode to an upper Haired position in a marine mode, at least one of the road wheels having wheel swponeion. the uspeion comprising a suspension member 15 having c Mung for 8UppO0g the wheel, the suspicion member being connected to the body by at least one upper link end one lower link, the beard bang ahead of any connection of We or each lower link with the vabicle body.

A McPherson type suspension Strut could act as an upper said link, because it locates the suspension member carrying the wheel beard.

20 Preferably, the bearing is also ahead of any connection of the or each lower link With the suspension member.

The wheel may love an asynnnetic run profile, as opposed to a synunetrical motorcycle wheel; in which case, We upper link(s) and lower link() support 6md wheel only on that side of Me wheel which faces the vehicle.

25 The upper link() and lower linl(o) may extend substantially transversely across the vehicle; again, in opposition to a motorcycle leading or 1rsiling link suspension, where such links would extend substantially along the Melville We suspended road wheel may longitudinally overlap at least one of the connection of a lower little to the vehicle body; end if driven, may 8160 longitudinally 30 overlap the vehicle eogino.

At lead two of the road wheels may each have a wicel suspension, the suspension comprising a w6ion member having a bluing for uppordug the wheel, the suepenshn member bemg connected to the body by at least one upper link and one lower

link, she bearing being ahead of any connection of the or each lower link with Me vehicle body. Preferably, the driven wheel(s) driven by a drive shaft or shafts have their shaft bearing(s) ahead of the lower linlc connections to the vehicle body. In an amphibious 5 vehicle hailing at least four wheels, preferably all the road wheels, or all of the driven wheels, are mounted to the vehicle's body with their beanage ahead of die or each lower link connection to the vehicle body.

In a particularly advantageous embodiment, at roast one of the lower suspension links is a track control ann.

10 The arranganeDt described may be found particularly suitable to a planing vehicle win a mid-moustod transverse engine, due to the hull shape and mechanical layout of such a vehicle. The weight distribution offered by a nud-mounted engine assists planing on water. Tle arrangement described also allow. a particularly robust mounting for a strut 15 actuator for a rotrwtablc suupenolon, which mounting must withstand retraction and deployment loads as well as normal uon loading. Should this Con layout be used in conjunction with He msdon layout of our copending application GB02,tfiled hemvitl), the contents of which are incorporated herein by means of reference, so that the outer CV joint on the or each triveshaft is a plunging joint; the 20 separation of the momdago to the ouspenon member of the suspension links and of the drivedft may be advantageous in package the bulky plunging CV jolt.

An embodiment of the invention will now be described by way of example win reference to the accompanyug drawings in which: 25 Figure I is a diagrammatic plan view of an amphibious vehicle according to the invention; Figure 2 is a perspective view of a rear suspension for the vehicle of Figure 1 as eecn from the mside of the vehicle looking outwards, and for clarity not showing 30 the road wheel; Figure. 3 and 4 are repecvely a diagrammatic plan and elevation of a front wspamion for the vehicle of Figure I.

In Figure 1, there is shown an amphibious vehicle I having body 3, and a mid mounted transverse engine 4 arranged to drive through transmission 6 a marine drive means, such as a pump jet 8; and via drive shafts 1 0, rear road wheels 1 2. The rear rosa 5 wheels have suspensions 14, which have suspension links 16; which will be described with reference to Figure 2. The front road wheds 13 have suspensions 15, which have suspension links 17.

Figure 2 shows an upright suspension member 20 having an upward extension 22, and a bearing 24 for supporting one end of drive shaft 10 on the inside; and the wheel on 10 the outside. Member 20 also has connection points for suspension links 16, as will be described below. A disc brake caliper (not shown) is secured to the suspension member at points 26.

Connected between the body of the vehicle and a member 20 are upper links 28 and 30 which connect to extension 22 at 32. Lower links 34 and 36 connect the lower part of 15 member 20 at 38 to the body of the vehicle. Il will be noted that tile connections between links 34 and 36 and member 20 are behind drive shaft 10. A track control amp 40 also connects between the lower part of member 20 and body 3 (fig. 1).

In order to retract the road wheel mto the body of the vehicle, a cylinder 42 is connected to the body by means of trunnions 44. A piston rod 46 acts between cylinder 42 20 and lower part of member 20 at point 48.

It will be seen that drive shaft 10 and bearing 24 are ahead of any connection of lower links 34 and 36 between the body of the vehicle and the suspension member. This ensures that there is no difficulty in finding room for the engine 4 and suspension connection points to body 3 of Me vehicle.

25 Figures 3 and 4 relate to the front wheels, which are also retractable and which are steerable; these each have a bearing 25 on the outside of suspension member 21. Numeral 27 represents the central axis of bearing 25; which is ahead of any connection of both lower links 35 and 37, together forming a wishbone between the body 3 of the vehicle and suspension member 21. An upper wishbone having links 29 and 31 connects with an 30 upward extension 23 of suspension member 21 and the body 3. It will be noted that as shown, the front of body 3 is swept up to present a good hydrodynamic profile on water; reducing the amount of chassis space available for lower suspension mountings in front of the centre of rotation of the wheel.

It may also be seen from figure 3 that the rim profile 33 of wheel 13, which is shown in section, is an asymmetric profile, as commonly used in car wheels; and that the upper and lower licks support wheel 13 only on that side of the wheel which faces the vehicle. 5 It will be appreciated by those skilled in the automotive engineering art, that a "connection" between two components may in fact comprise several other components, e.g. a bolt, nut, and washers; which may have a significant length. For clear understanding of the claims, the term "connection" should be understood as the plane in which two adjacent components meet.

10 It will also be understood that where opposite ends of a suspension link are attached to other components in planes at right angles to each other, it cannot be determined whether one plane is ahead of the other, as the planes intersect. In this case, the mounting positions may be compared by defining a plane at one end of the link as passing through the longitudinal centre line of a connecting element such as a bolt or stud.

15 It should also be noted that for clarity, figures 3 and 4 do not show components such as the wheel hub and brake which would be needed to complete the wheel mounting arrangement. An advantage of the present arrangement of the lower wishbone 35137 being behind the centre of rotation of each front road wheel 13 relates to vehicle dynamics.

20 Vehicle weight ahead of the front wheels is reduced, which may improve steering response. Where the amphibian is designed for off road driving on land - for example to allow it to reach water - it is possible to keep vehicle front overhang to a minimum, so as to reduce grounding by improving the ramp angle. (The Wont ramp angle being defined, particularly for off road vehicles, as the angle to the horizontal of a line drawn as a tangent 25 to the front wheel to the foremost part of the vehicle) Furthermore, the wheelbase is able to be made as long as possible in proportion to the vehicle's total length. A yet further advantage is that in the case of the vehicle of Figure 1, where the vehicle narrows towards the front, it is possible to ensure that the lower wishbones can be kept as low as possible to provide a stable support system to each Wont Wheel.

It will be appreciated that further modifications to the suspension layout may also be made as required without departing from the spins and scope of the invention. In particular, n may be found convenient to apply such a suspension to a vehicle with four or

s more driven wheels; and to use for example a McPherson strut suspension system, as opposed to the tipper wishbone layout described and illustrated. The layout of suspension arms and locations shown is of course applicable to suspensions using a range of spring media, for example coil springs, air or hydraulic springs, or simple or compound torsion 5 bars; with and without further accessories such as anti-roll bats Various suspension retraction mechanisms may be used to convert ale vehicle from road mode to marine mode and vice versa, as are known in the amphibious vehicle art.

The term 'body" may be taken to mean an open flame, a monocoque, or any other enclosure.

Claims

1. An amphibious vehicle having a body, retractable road wheels mounted to the body and arranged to be moved Bom a lower road engaging position in a land 5 mode to an upper fatted position in a marine mode, at Iwt one of the road wheels loving a wheel suspension, the suspension comprising a suspension member having a bearing for supporting the wheel, the summon member being connected to the body by Bt roast one upper link and one lower linl, the bearing being ahead of any connection of the or each lower link with the vehicle body.

2. An amphibious vehicle according to claim 1, characterized that the bong IB also ahead of any connection of the or each louver little with Me suspension member.

3. An amphibious vehicle according to clann I or claum 2, characterized in that the 15 wheel has anasymmetnc rim profile, and the tipper link(6) end lower link() support Bait wheel only on that side of the wheel which faces the vehicle.

4. An amphibious vehicle according to any of the above claims, characterized in that the upper link() and lower link(o) extend substantially tranovereely across the 20 vehicle. S. An amphibious vehicle according to any of the above claims, characterized in that We road wheel loryptudinly overlaps at lent one of Me connections of a lower link to the vehicle body.

2S 6. An amphibious vehicle according to any of the above claims, characterized in that at least two of the road wheels each have a wheel ewpension, the suspension comprising a suspension member hoe a baking for upportir Me wheel, Me suspension member being connected to the body by at least one upper link and one 30 lower link, the bearing being ahead of 'my connection of the or owh lower link with the vehicle body.

7. An amphibious vehicle according to any of the above claims, characterized in that the driven wheel() driven by a drive shaft or shapes have their shaft boaniu(B) ahead of the lower link connection(s) to the vehicle body.

5 8. An amphibious vehicle according to any of Me above claims, characterized in Mat the driven road wheel(s) longitudinally overlap the vehicle engine.

9. An amphibious vehicle according to any of the above claims, characterized in that the vehicle has at lout four road wheels, all of which wheels are mounted to the 10 vehicle'6 body with their bovines ahead of the or each lower link connection to the vehicle body.

10. An amphibious vehicle according to any of claims I to 8, characterized In that the vehicle has at least four road wheels, and in that all of the driven wheels are 15 mounted to the vehicle'. body with their drive shah boarmge ahead of the or each Iowa link connection to the vehicle body.

11. An amphibious vehicle according to any of the above claims, chazeoterized in that at least one of the lower suspension linlu is a track control arm 12. An amphibious vehicle according to any of the above claims, characterized in dolt the vehicle is a planing vehicle win a midmounted transverse engine 13. An amphibiooo vehicle according to any of flu above claims, characterized in that 25 a suspension upper link comprises a swponsion strut.

14. An amphibious vehicle substantially as described win reference to any one or more of Figura 1, 2, 3, or 4 of the accompanying drawings.