MXPA96003612A - Hydraulic suspension with independent pitch and roll control - Google Patents

Abstract

A vehicle hydropneumatic suspension comprising four double acting rams (1, 2, 3, 4) each between respective one of four spaced wheels at corners of the vehicle. First conduits (9, 11) connecting main chambers (1a, 2a) of front rams (1, 2) with diagonally opposite rear cylinder minor chambers (3b, 4b), respectively, and, second conduits (10, 12) connecting minor chambers (1b, 2b) with main chambers of diagonally opposite rams (3a, 4a), respectively. A load distribution unit (13) has two cylindrical chambers (13a, 13b) each separated by a piston into, respectively, chambers (14, 15) and (16, 17). Conduits (9a, 10a, 11a, 12a) connect respectively conduits (9, 10, 11, 12) to chambers (14, 16, 17, 15). The pistons are connected by a resilient means (20) to allow relative piston movement to provide for independent control of pitch and roll of the vehicle.

Description

HYDRAULIC SUSPENSION WITH INDEPENDENT INCLINATION AND BAMBOLEO CONTROL This invention relates to improvements in the suspension system for a vehicle, and relates specifically to the control of the arrangement of the body of the vehicle relative to the ground when the vehicle is subjected to variations in the contour of the surface it is traveling. In recent times, there has been a trend towards suspension systems on resilient springs, which incorporate variable amounts of damping and resilience in an attempt to improve the stability of the vehicle and reduce the movement of the body of the vehicle in relation to the surface that is traveling. A series of suspension systems known as "active" and "semi-active" suspensions for vehicles has been proposed to include systems that operate on the basis of fluid compression and / or displacement, and these systems currently in use incorporate a pump, to maintain the working fluid at the required pressure and perform the distribution of the same at high REF: 22993 speed, and sophisticated control mechanisms to regulate the operation of the suspension system according to the operating conditions of the vehicle and / or the road, detected . These known systems incorporating pumps and electronic control systems, which both usually operate continuously while the vehicle is in operation, are comparatively expensive to build and maintain, and require a substantial energy input. Therefore, they find limited acceptability in the vehicle industry. There has previously been published an International Patent Application (International Publication Number WO 93/01948, International Application Number PCT / AU92 / 00362 and dated February 4, 1993) which describes a "passive" hydropneumatic vehicle suspension system. This described passive suspension system has many of the advantages of "active" or "semi-active" suspension systems, while avoiding the complexity and cost of these systems, thus making it more acceptable to the automotive industry.

In the suspension system described in that patent, a hydraulic ram or cylinder of the front wheel and the rear wheel ram diagonally opposite have the upper chamber of the front ram interconnected with the lower chamber of the rear ram and the lower chamber of the front ram interconnected to the upper chamber of the rear ram. Similarly, the respective chambers of the other front ram and the rear ram are equally interconnected. In this way, two individual fluid circuits are provided, each comprising a front ram and a diagonally opposite rear ram. Each of the conduits that interconnects the respective upper and lower chambers, normally has at least one conventional pressure accumulator in communication with them. The two circuits are interconnected to a pressure compensating device that is arranged to maintain a substantially equal pressure in the two circuits, as described in detail in the Patent Application.

International No. WO 93/01948, previously referenced. This proposed vehicle suspension system, previous, avoids the use of ordinary springs (for example, spiral springs, leaf springs or torsion bars) as well as conventional telescopic shock absorbers (commonly referred to as shock absorbers) and anti-roll bars. wobbling or rolling The elasticity or resilience is provided by means of accumulators filled with gas with the valves of the dampers located in the mouths of the accumulators. Conventional vehicles equipped with springs with accumulators are known to provide good levels of comfort when traveling on low amplitude ground surfaces at higher speeds. However, gas-filled accumulators to provide a smooth ride also tend to induce and exaggerate the wobble and tilt movements, unwanted, when used without swaying or rocking stabilizer bars. Many of the hydropneumatically suspended vehicles are therefore usually provided with wobble or swing rods made of spring steel which mechanically and transversely interconnect the two wheels of each axle, thus limiting the wobbling but not tilting movements. In the suspension system described above (Patent No. WO 93/01948) excessive wobble movements are prevented and hydropneumatically controlled without the wobble stabilizer bars and the amount of wobble allowed is defined by a function of the ratio of the diameters of the cylindrical holes of the rams (of the diagonally opposed rams) to the diameters of the rods of the rams, and with respect to their stroke lengths and with respect to the amount of gas within the various accumulators of the suspension system. It should also be noted that the type of wheel geometry and the location and design of the various components can give some components a mechanical advantage over others, thus providing, for example, an appropriate but different amount of stiffness of wobble in the front in relation to the rear of the vehicle that to a degree, defines whether the vehicle is under- or oversteer when it has a turn. In conventional vehicles, the wobbling forces are prevented by wobble rods, or rocking, that is to say, the steel bars of springs, formed, mounted, transverse, that must be formed in the torsion as soon as any wobble of the body occurs.

Conversely, the tilt movement in the longitudinal plane is usually only partially prevented by the design of the suspension geometry with spring resonances which are avoided through the proper selection of the dampening and elasticity amounts, frontal and rear, without the need for any mechanical equivalent of direct action of the wobble bar. This is because the tilting actions in the longitudinal direction are less severe than the wobbling, transverse actions. It has been found that the previously described system provides adequate comfort, stability and wheel loading, relatively consistent, regardless of the relative travel positions of the wheel, during many maneuvers such as the axle joints and absorbed energies, individual, wheel, however, the magnitude of the tilt and wobble control is governed by the same components and the effective, linear stiffness of each wheel in relation to the vehicle body at any inclination or wobble is typically the same. In vehicles based on high wheels, this is transferred to the characteristics of rigid inclination in relation to the wobble. In vehicles based on low wheels, the rigidity of inclination and wobble become closer in magnitude. Since most vehicles are considerably narrower than they are long, and due to other geometrical effects, it has been found that wobbling is more difficult to control than tipping, as noted above. In fact, when the suspension system is designed to adequately contain the wobble movement, the tilting movements can be overcompensated, consequently, in the system. This can be further clarified as follows: In order to contain the high wobble forces resulting from a high center of gravity with respect to the rams located relatively closer (in the transverse direction), it is necessary to supply rams with a greater difference in the diameters of the rod and the hole. Therefore, this can automatically generate an unnecessary amount of resistance or control of the inclination in the longitudinal direction and this can lead to discordance of the ride quality in some conditions. In particular, it has been found that while the alteration of the body due to the movements of the joints of the axes and minimizes the energy absorbed from the individual wheel, road surfaces that cause double energies absorbed from the wheel on an individual axis (such as "speed peaks") or sinusoidal road profiles may disturb the suspension system previously described. Typically, this occurs when a length of the base of the vehicle wheel approaches half the space of the ridges placed along the road surface. To avoid traversing this kind of road surface, smoothly (excessive inclination movements are induced) both axes need to become independent in their movement, however, the hydropneumatic system, interrelated, previously described, interprets these movements as movements high-speed tilt and therefore try to prevent them as if they were unwanted tilt movements. This type of resistance to high-speed inclination and overcompensation manifests itself as an inappropriate discordance of the inclination that can become additionally uncomfortable when the vehicle moves on protrusions or repeated depressions causing resonant, increasingly exaggerated responses. inappropriate. Therefore, it is the object of the invention to provide a vehicle suspension system that will provide a more optimal relationship between the control of the inclination and the wobble of the vehicle. A suspension system for a vehicle body having a plurality of wheels arranged in a spaced relation, lateral and longitudinal, to support the body of the vehicle, this suspension system comprising a means of ram, individual arranged between each wheel and the body of the vehicle, each ram means comprising a cylinder, a piston and a rod, a first means and a second means of equilibrium or compensation, each having two chambers and a force transfer means separating the chambers and can be displaced in response to the pressure conditions in the respective chambers, this means of force transfer of each equilibrium means that is operably interconnected to transfer the force between these to achieve a balanced or compensated state between the two transfer means, the two chambers of each equilibrium means including an inner chamber adjacent to the interconnection and a opposite outer chamber, the inner chambers of each balance medium that are in communication for fluids, res pectively, with the ram means at one end of the vehicle, and the outer chambers of each balancing or compensation means that are in communication for fluids, respectively, with the ram means at the opposite end of the vehicle body, such that both chambers of the first balancing or compensation means are in fluid communication with the ram means on one side of the vehicle body, both chambers of the second balancing or compensation means being in communication for fluids with the ram means in the opposite side of the vehicle body; the interconnection between the force transfer means that is adapted to transfer the force and allow relative movement between the force transfer means to provide additional resiliency in a tilting direction of the vehicle body relative to a wobble direction of the body of the vehicle. The suspension system described above has the ability to maintain in general all the wheels in traction contact with the surface being traveled, in particular in situations where the extreme irregularity of the surface, as experienced in cross-country operation. Furthermore, effective control of the tilt and rebound wobble of the vehicle is achieved, by virtue of the fluid system that controls the concurrently unidirectional movement of either of the two longitudinally adjacent wheels or the two laterally adjacent wheels relative to the vehicle. The maintenance of the traction contact of all the wheels with the ground is achieved by the pressure conditions in the respective rams and the control of the inclination and wobble is by the pressure and the movement of the fluid between the rams and the means of balance or compensation.

Preferably, the first and second balancing means comprise a first and a second control chamber each divided into two cavities by movable walls, respectively. The two cavities of the first control chamber communicate respectively with the rams of the front and rear wheels on one side of the vehicle, and the cavities of the second control chamber communicate respectively with the fluid cylinders of the front and rear wheels on the opposite side of the vehicle. The force transfer means that is arranged to interconnect the movable wheels to transfer the force between them to achieve a balanced or compensated state between the movable walls of the respective control chambers. Also, the interconnection between the force transfer means includes a resilient means adapted to transfer the force and to allow relative movement between the movable walls to achieve balance or compensation between the net forces in the respective movable walls. Conveniently, the resilient means is arranged to be able to transfer both tension and compressive forces. Preferably, the resilient means is a metal or gas spring or a member of resilient material, such as a rubber or plastic member. Conveniently, one or each movable wall can be in the form that is resiliently deformable, so that the total volume of the control chamber, occupied by the fluid can vary in response to the pressure in the two cavities of the respective chambers. The inclusion of a resilient means as part of each movable wall in addition to the resilient means interconnecting each movable wall, allows the adjustment of both the inclination and wobble characteristics, individually and independently. Hydraulic rams can be either double or single action type. In any arrangement, the chambers of the rams that are providing the support of the vehicle, are connected to the means of balance or compensation. If the balancing means is for restraining the lateral wobble of the vehicle while still allowing a degree of tilting resilience, then the chambers of the first balancing means are in communication with the fluid chambers of the wheels on a longitudinal side of the vehicle and the chambers of the second balancing means are in communication with the fluid cylinders of the chambers on the other side of the vehicle. If the tilting movement of the vehicle is the dominant factor to be restrained, while still allowing some additional resilience around the wobble axis, then the fluid cylinders of the front wheels are in communication with the first balancing chamber and the fluid cylinders of the rear wheels in communication with the second balancing or compensation chamber. It will be appreciated that the provision of the resilient means interconnecting the movable walls in the respective control chambers allows at least a part of the movement of a wall to be absorbed by the resilient means, between them, so that a different degree of movement is transferred. to the other moving wall. The resilient means can be either resiliently elongated or compressed and in this way the difference in the degree of movement of the respective movable walls can be by means of an increase or decrease. The effect of this differential on the degree of movement of the respective movable walls is that a smaller degree of movement is transferred to the other wheels in response to a severe or rapid movement of both wheels on a vehicle axis in the same direction, it is that a lesser degree of movement is transferred to the other wheels, thus reducing or even reversing the undesirable tilt control characteristics mentioned above. When mobile walls or members are built incorporating resilient means, other types of resilient means such as the accumulator can be omitted. A suspension system for a vehicle that has a load-bearing body, on a pair of front wheels that couple the floor and a pair of rear wheels that connect the floor connected to the body to support it and each wheel and can be displacing relative to the body in a generally vertical direction, a suspension system comprising a double action ram interconnected between each wheel and the body, each ram including a first and a second chamber filled with fluid that vary in volume in response to relative vertical movement between the respective wheel and the body.

Each ram of the front wheel is connected to the rear wheel ram diagonally opposite by a respective pair of fluid communication conduits, a first of the pair of conduits connecting the first ram chamber of the front wheel to the second ram chamber. of the rear wheel and the second of the pair of ducts connecting the second chamber of the front wheel ram to the first ram chamber of the rear wheel. Each pair of conduits and rams of the interconnected front and rear wheels, thereby constituting a respective closed circuit, whereby a first and a second closed circuit are formed, and a pressure distribution means interposed between the first and second circuits. the second circuits closed and adapted to achieve substantially the balance of the pressure between these closed circuits, the means of distribution of the pressure comprising two primary pressure chambers, each divided into two secondary pressure chambers * by a piston means, the piston means of the primary chambers that are operatively interconnected to transfer movement between them, and allow the independent, controlled movement to vary the relative position in the middle of the piston in the primary pressure chamber, this independent controlled movement that maintains substantial balance of the pressure and that allows the resilience of the inclination, controlled, additional. The invention will be more readily understood from the following description of a number of alternative arrangements of the vehicle suspension system with reference to the accompanying drawings. In the drawings, Figure 1 is a schematic representation of the suspension system.

Figure 2 is a schematic, enlarged view of the load distribution unit as incorporated in the suspension system shown in Figure 1.

Figures 3 through 7 illustrate alternative forms of the load distribution unit that can be used in the suspension system shown in Figure 1.

Figures 8 and 9 are schematic representations of a vehicle with a version of the suspension system incorporating individual action hydraulic rams to support the vehicle body.

Figure 10 is a schematic representation of a suspension system incorporating an additional, alternative load distribution unit.

Figure 11 is a suspension system as shown in Figure 1 incorporating a closing arrangement of the load distribution.

Referring now to Figure 1, four rams or hydraulic cylinders, 1, 2, 3, and 4 are located between the vehicle body / chassis (not shown) and the wheel units (not shown) so that each wheel moves. Relative to the chassis, which causes the rams to contract or extend. As shown in Figure 1, the ram is functionally related to the front left wheel while the ram 2 is similarly associated with the right front wheel. The ram 3 is associated with the wheel on the right, rear side while the ram 4 is located or located between the left rear wheel and the chassis. Therefore, the front of the vehicle is shown towards the top of the page. Four conventional oil-on-gas accumulator springs 5, 6, 7, 8 are shown, such that the accumulator 5 is associated for example with the left, front wheel and the accumulator 8 with the left, rear wheel. The portion or chamber 5a, 6a, 7a, 8a of each of the accumulators is filled with gas, while the portions 5b, 6b, 7b, 8b filled with oil, hydraulic are in communication with the gas chambers 5a, 6a, 7a, 8a. The oil and gas chambers are normally separated with a diaphragm, flexible or free piston. The damper valves 5c, 6c, 7c, 8c are conveniently located in the mouths of the accumulators 5, 6, 7, 8. When the double-action wheel rams are used, they are usually conventionally divided into two reciprocal chambers that they include a larger camera, 2a, 3a, 4a and a smaller chamber Ib, 2b, 3b, 4b, the larger chamber accommodating a piston rod. The upper chamber is connected to the lower, lower chamber 3b of the diagonally opposite wheel by means of a tube or conduit 9 while the upper chamber 3a of this wheel is connected to the lower chamber Ib of the first cylinder by means of a tube 10. These tubes, therefore complete a pair of fluid circuits that interconnect a pair of wheels diagonally opposite, the camera from the top to the bottom, and vice versa. The other pair of diagonally opposed wheels are similarly interconnected from 2a to 4b via conduit 11 and from 4a to 2b via conduit 12. Located (centrally) in any convenient location and in any suitable manner is a component that can be refer to as the load distribution unit 13. An earlier version of a load distribution unit is described in the applicant's prior patent No. WO 93/01948 and is usually constructed from between the cylindrical tube by a fixed wall and having a movable piston in each chamber.

The two pistons in the previous proposed construction were connected directly by a rod that extends across the entire length of the cylinder, so that both pistons are caused to move together in unison resulting in two of the chambers becoming simultaneously lengthened while causing the other two to contract in a reciprocal manner at the same time. This design has been found to lead to some problems inherent in certain circumstances described as follows: In the construction described previously, the piston and rod assembly is unable to move in response to two absorbed energies of the octagonal wheel (such as movements on the crests of parallel speed). The chambers of the load distribution unit were described as being hydraulically connected to the wheels in a sequence such that the changes in pressure and volume of the fluid resulting from the two orthogonal energy absorbed by the wheel, opposed to each other in order to to prevent piston movements inside the discharge distribution unit. The proposed, original system was specifically designed to allow only the movements of the piston and rod in the load distribution unit as a response to the diagonal shaft joints that induce changes in pressure and fluid volume in the distribution unit load to ensure the optimal weight that is carried by each of the four wheels without considering their travel positions of the wheels. As a consequence of the restriction of movement of the piston and rod assembly in response to the two orthogonal energies absorbed from the wheel, the tilting movement of the suspension becomes perceptible in specific situations. When, for example, the front pair of wheels encounters an obstacle, such as a ridge of speed across the width of the road, fluid is first expelled from the chambers at the top of both front rams, and some of this fluid is force to enter the associated accumulators via the damper valves. In general, the greater the resistance offered by these damper valves, the greater the volume of fluid that will be forced to the other parts of the connected hydraulic system, and inevitably some fluid enters the lower, diagonally opposed chambers. The transfer of the volume of fluid from the front rams to the lower chambers of the rear rams forces the associated pistons upward thereby contracting the two rear rams, which in turn tend to cause the rear part of the vehicle to bend. The delay in this movement in some frequencies may cause the rear part of the vehicle to still "move down or bend when the rear pair of wheels meets the same speed crest and this can lead to a quick tilt response since it requires a very fast change in the direction in the rear of the vehicle, the additional impact on the wheels of the rear axle also then contracts the rear rams and this additionally compresses the gas in the associated accumulators.As the rear wheels start from the bottom side of the velocity ridge, the cumulative compression of the gas in the gas chamber of the rear accumulator caused by the rapid succession of the absorbed energies of the front and rear wheels, is allowed to expand and thereby expel fluid from the rear chambers of accumulator fluid .This can then cause the rams to over extend causing the rear of the Vehicle is lifted beyond the level required to restore normal ride height. If more crests are found later on the road by the front wheels before the vehicle has settled, a resonant response can be established and may be exaggerated as quick reversals in vehicle movement take place. These movements can be canceled at least partially by the dampers in the mouths of the accumulators as well as by the limiters located in the ducts. Nevertheless, several permutations of unpleasant responses may occur for poor road surfaces, depending on the length of the base of the wheel, the distance between the protuberances, speed, damping amounts, elasticity amounts for example the physical location of the rams with with respect to the geometry of the wheels. The load distribution unit 13 according to the present invention provides resilience to decrease / suppress small amplitude, high frequency absorbed energy, and also provides some additional resilience in either tilt or wobble movement in a specific manner. The load distribution unit 13 has similarities in construction to the unit described above since four cameras are provided. However, the one-piece piston rod referred to in the above specification is replaced with two piston rods with a resilient shock absorber that interconnects the two piston rods. Figures 1 to 11 show several alternative constructions of the load distribution unit 13 which are all generally divided into two cylinder portions 13a, 13b each of which comprises two reciprocal volume chambers, 14, 15, 16, 17. The same reference numbers are used in each of the Figures for corresponding components. In Figure 1 and 2, the load distribution unit 13 is shown with four main chambers 14, 15, 16, 17, respectively in direct communication for fluids with branch lines 9a, 12a, 10a, lia, respectively, and these are in communication for fluids with the chambers 3b and 4a, 2b, and 3a, Ib, and 2a, 4b, of rams, respectively via the conduits 9, 12, 10, 11. The chambers 14 and 15 within the 13a of the cylinder act in a reciprocal manner therein. As * cameras 16 and 17 do in the other portion 13b of cylinder. Each cylinder portion 13a, 13b supports a piston assembly 18, 19, each piston assembly having a piston 18d, 19d, an outer piston rod portion, 18a, 19a and an inner portion of piston rod 18b, 19b. The two outer portions of piston rod 18a, 19a normally end outside the chambers at both ends of each of the cylinders to allow the pistons to move freely with respect to the cylinders. The ends of the piston rod inner portions 18b, 19b that typically occur with each other can be provided with any convenient joining means such as the disc accessories shown at the ends of the rod, numbered 18c and 19c. Between the opposing piston rod assemblies, a resilient member or damper 20 is introduced to provide resilience in any compression or tension or both. In the example shown in Figure 2, the resilient member 20 may comprise a portion of rubber that meets or joins the discs 18c and 19c in Figure 2. Therefore, any movement induced by changes in pressure and volume of the fluid, in a pair of the reciprocal chambers (such as the chambers 14, 15 in the cylinder portion 13a) are transferred directly, via the rod 18 and through the resilient member 20 to the other cylinder portion 13b of the unit 13 of distribution of charge via the rod 19 and thus in the other pair of chambers 16, 17. The purpose of this indirect connection / coupling between the two cylinder portions can be described as follows: It will be seen in Figure 1 (in conjunction with Figure 2) that the upper chambers 2a of the rams associated with the front wheels are in fluid communication with the chambers 14 and 17 within the opposite cylinder portions of the load compensation unit 13 . If an obstacle is encountered (such as a speed crest), by both front wheels, simultaneously, the fluid will be expelled out of the cameras la and 2a superiors. Some fluid will initially enter the nearest accumulators 5 and 6 through the buffer valves 5c and 6c and some will be distributed to the rear ram and to the control unit. Some fluid under the increased pressure will therefore enter the branching lines 9a and lia associated with the front chambers of the upper part of the rams 1 and 2. This fluid then enters chambers 14 and 17 at opposite ends of the distribution unit and pushes these chambers to elongate them. As they lengthen in volume, the two piston and rod assemblies 18, 19 are forced to slide together and this compresses the resilient member 20 which is located between the two cylinder portions 13a and 13b. As the two piston assemblies 18, 19 are forced to move towards another of the chambers 15, 16 (which are reciprocal with the chambers 18, 19, respectively) they progressively decrease in size and expel fluid towards the lines 12a and 10a of branching, in conduits 12 and 10 and thus introduce fluid at a slightly higher pressure in cylinder chambers 2b, 4a and Ib, 3a. This has the effect of further softening the impact of the speed crest on the front axle by pushing the pistons inside the rams 1, and 2, and more importantly providing fluid to the chambers 3a, 4a of the upper part of the rams. rear rams that tend to raise the rear of the vehicle as the rams extend in preparation for the rear wheels impact the same peaks of speed. Therefore, it should be noted that the member The resilient thus greatly reverses the adverse inclination response in the longitudinal plane of the vehicle relative to the construction proposed above and this then softens the tilt discordance and helps to stabilize the tilting resonant movements. It should also be understood that while the configuration described with reference to Figures 1 and 2 modifies and smoothes the tilting movements, it does not effect the rigidity of the wobble. However, if the wobble rigidity was required to be reduced instead of the tilt rigidity, the branch line conduits need only be changed to connect to the different appropriate chamber in the load distribution unit. An additional benefit of introducing a resilient member 20 in the load distribution unit is that the overall smoothness of the vehicle and comfort can be improved by interrupting the resilient member 20 without sacrificing the stability of the wobble. It is also possible to reduce the amount of gas in the accumulators below what would normally be required, so that the reduction in gas volume adds wobble smoothness without adversely affecting comfort levels. Additionally, the stability of the wobble is not reduced as more weight is loaded into the vehicle since the gas in the accumulators becomes more compressed which effectively reduces the wobble. However, the introduction of a resilient member such as the rubber component 20 can provide some dynamic insulation between the wheels when faster movements of the small shaft joints are occurring. Since the movements of the joints of the large axis occur only when driving or driving at slower speeds such as when operating cross-country, the consequence is that they are low pressure impulses that energize the resilient member that causes thermal insulation , and therefore, during the slow joints of this dynamic isolation is not perceptible. The smoothness of the resilient member 20 must be such that the two piston assemblies 18, 19 must follow each other substantially (or pull and push each other without much difference or loss of movement between the two piston assemblies 18, 19). when there are energies absorbed from the wheels diagonally placed, individual or slow, which occurs such as when the axle joint is taking place, but the resilient member should not be too hard that when the two wheels on the same axle meet a protrusion or depression Suddenly simultaneously, the resilient member is not easily deformed to allow a delayed response in adverse tilting movements. In practice, the pressure pulses are significantly greater during the high speed absorbed energies of the two wheels than during the low speed articulation when some rigidity is required, so that there is some freedom with the choice of the resilient means 20. In this context, the resilient member can optionally be replaced with any suitable damping mechanism that can similarly delay the transfer of force and movement from one tree to the other without a resilient member such as a spring between the trees. In Figures 3 to 7, resilient means are illustrated in different forms, such as types of rubber or urethane blocks, spiral springs, or gas accumulators. It should be understood that within the scope of this invention disc springs and other resilient means can be used in an equal manner, and the damping mechanism only serves to return the component parts to their correct, relative positions. In this respect, the two cylinder portions 13a, 13b of the load distribution unit 13 are understood to be mechanically joined together, so that the relative movements of its piston assemblies 18 and 19 do not cause its housing cylinders to move as well. The numbered connecting shoes 21a, 21b therefore illustrate a means of joining the chassis (or any convenient means) of the two cylinder portions 13a, and 13b, respectively. The resilient means 20 is normally maintained either in compression or tension depending on which fluid conduits are connected to which chambers in relation to which end (one side) of the vehicle is heavier at any given time and also with respect to the relative sizes. of the holes or inner diameters and rods of the rams 1, 2, 3, 4 that define the relative pressures of the system. Therefore, it is necessary to design all the components in a relative manner, so that the resilient member 20 is given the appropriate amount of elasticity or hardness / durometer that varies to compensate for any deviations and / or expected variations in weight. It should be noted that since the resilient member 20 is often a spring of some nature, it may be beneficial to introduce a damper component in the load distribution unit to dampen any unwanted spring resonance within this unit. The damping means can be designed in the load distribution unit as an integral part within the body of the unit. Alternatively, the two ends of a shock absorber (such as the telescopic shock absorber, numbered 22 in Figure 2, can be attached to the two ends of the rod (as in 18a and 19a) so that the shock absorber is extend and contract in direct response to any movement induced by the absorbed, orthogonal energies of the wheel but not by the diagonal absorbed energies of the two wheels such as when the joint is occurring.This further ensures that the damping occurs specifically and only when This is important so that even optimal ground pressure occurs in the wheels during the axle articulation while additional damping occurs when the wheels impact obstacles. parallel to the successive axes.The shock absorber unit should be considered as an optional component. carrier since it allows the tuning of specific functions in the suspension system. The shock absorber can also be used to delay the responses and interactions between the front and rear axles so that the energy absorbed at sensible frequencies resulting from road conditions of the length of the base of the wheel will not disturb the smooth passage of the wheels. vehicles. The dampers can also take the form of (optionally variable) limiters 9b, 9c, 12b, 12c, 11b, 11c, 10b, 10c within the conduits, which allows individual tuning of the various components. For example, when the limiting dampers 9b, 10b, 11b, 12b are introduced, the fluid is restricted from communicating with the lower chambers Ib, 2b, 3b, 4b so that the resilient effects of the distribution unit 13 are maximized. load. Conversely, when shock absorbers 9c, 10c, 11c, 12c are used mainly, this prevents the free communication of fluid from the rams to the load distribution unit and encourages the vehicle to act on the lower chambers Ib, 2b, 3b, 4b of battering rams with very different consequences. The adjustment of the balance or compensation of the constraints exerted by the limiters 9b, 10b, 11b, 12b with reference to the limiters 9c, 10c, 11c, 12c provides the ability to allow the appropriate tuning of the total damping forces acting on the vehicle. This tuning can also be achieved through the careful selection of duct sizes to provide that the proper amount of friction arrives at similar cushion responses. Figure 3 is another alternative method of construction of the load distribution unit 13. In this modality, the two cylinder portions 13a, 13b are remotely coupled by the resilient means 20a, which may comprise a cylindrical portion 19c attached to the rod portion 19b in place of the flange 19c in Figure 2. At the end of the portion Cylindrical which gives the other rod there is a hole that can be easily accommodated to the opposite rod portion 18b. The end of the opposite rod portion 18b extends through the hole in the cylinder 19c so that a flange 18c provided at the end of the rod portion 18b is located inside the chamber and towards the center of the cylinder 19c. On either side of the flange 18c there is provided a resilient means such as a coil spring or disc or block of numbered rubber 18e, 19e. Alternatively, the chambers on either side of the flange or piston 18c can be charged with gas to provide a gas spring to locate the piston 18c far away within the cylinder 19d. An advantage of the resilient medium such as 20a out of 20 is that the two resilient members can be constructed individually, in a different manner to better support their required functions as tension or compression members with reference to the other parts of the suspension system. The resilient member 20a can alternatively be constructed by using a shock absorber (cushion unit) provided with one or two spiral springs, concentrically, internally or externally of the telescopic component. Figure 4 shows another alternative to the central, resilient member 20 of Figure 2. This version differs from that shown in Figure 2 in that the resilient member 20 is kept in compression within the cylinder means 18c, 19c regardless of whether the two half cylinders 18c and 19c move away from each other or toward each other. By keeping the resilient means in compression, the mechanical problems of bonding the rubber blocks to the end flanges 18c and 19c of the embodiment of Figure 2 are eliminated. In Figure 5, a loaded gas version of the member is illustrated. resilient In essence, the two rod ends 18c, 19c are constructed as pistons having seals within the cylindrical chamber 21 which is an extension of the portions 13a, 13b. The two pistons subdivide the cylinder 21 into three smaller chambers 21a, 21b and 21c as shown. The chambers 21b and 21c, on either side of the central chamber 21 are interconnected by means of the conduit 21c so that these two chambers remain substantially at the same pressure while still maintaining reciprocal in the volume. The purpose of this is to prevent a deviation development that would substantially center the pistons 18c, 19c thereby restricting the articulation of the axles with the uniform load of the wheels. Two gas loading valves 22a, 22b are provided, so that a valve 22a allows the chamber 21a to be loaded at an appropriate pressure to withstand the pressure difference caused by the front of the vehicle weight exceeding the rear part, and the valve 22b allows the chambers 21b and 21c to be loaded together to provide sufficient resilience to maintain the height of the vehicle when the vehicle can load more at the rear as during a tilting movement. Figure 6 is still another version of the central resilient means and represents another gas loaded form of the resilient medium. In this case, the two cylinder portions 13a and 13b are located parallel, so that their ends 18c and 19c do not meet with each other but in the same direction. The central cylindrical chamber 21 is divided so that one half is located or located adjacent a cylinder portion 13a and accommodates the piston 18c, and the other half of the cylinder 21 located adjacent to the other cylinder portion 13b and accommodates the piston Í9c. The chambers 21b and 21c are joined by the conduit 21d as in Figure 6 so that they maintain a substantially equivalent pressure. As the chamber 21a is now divided into two sections 21a (i) and 21a (ii) they are now similarly joined by means of the conduit 21e.

In operation, the version shown in Figure 6 is the same as that shown in Figure 5, but the advantage of the version in Figure 6 is that the total length of the load distribution unit 13 is reduced which facilitates the packaging. Figures 7a and 7b show another version of the load distribution unit in which the two cylinder portions 13a and 13b are placed in parallel. In this version, however, the resilient gas spring chambers are replaced with rubber blocks or spiral springs in the following manner; Figure 7a represents a similar elevation view equivalent to that shown in Figure 6. Figure 7b is another elevation diagram drawn at right angles to the first and included for clarity. The inner portions 18b, 19b of piston rod are elongated to extend to the points 18d, 19d. At some point along the length of the extended rod portions are the points 18c, 19c which are equivalent in function to the numbered parts 18c and 19c in the other figures. In these figures, 18c and 19c may typically comprise a disk mounted and slidably located on the rods 18b and 19b. Exiting from each of these two disks on the opposite sides, there are two projections or small rods that carry four arms 18e, 19e. These in turn are joined in a similar manner flexibly to the points 18f, 19f to a common oscillating arm 23 which is mounted on pivot to the same member as that which is located in the rest of the body of the distribution unit 13 of cargo. The units 18c and 19c of projections and disks are therefore mounted in a mechanical and reciprocal manner with respect to each other, so that if one moves "upwards" the other moves "downwards". The resilient members 24a and 24b are functionally similar to the resilient means 18d, 19d in Figure 3 or the gas springs 21a (i) and (ii) and 21b and c in Figure 6 for example. The example shown in Figure 7, the resilient means 24a and b may be rubber or urethane blocks placed concentrically around the rods 18b and 19b held between marked end stops 25a and 25b which are prevented from moving on the rods by any means convenient as shown.

Therefore, if the wheels of the vehicle impact a speed crest as an axis, the rod portions 18a and 19a will cause both to be pushed down (with reference to the drawings) which will cause both sets of rubber blocks 24a become compressed between the discs 25a and 18c, 19c while the other rubber blocks 24b are allowed to extend. The impact of the two front wheels will therefore be brought to a degree by the blocks 24a and a similar simultaneous impact on the two rear wheels will cause the compression of the rubber blocks 24b to bear some of the impact. However, if the impact is only on the diagonally opposite wheels as during the articulation of the shaft, the four rubber blocks will remain substantially undisturbed while a piston rod can be extended in one way, the other is contracted in the opposite direction . In this way, the load distribution is optimally maintained during the movements of the diagonal wheels while the two absorbed energy of the orthogonal wheels is partially reduced by the resilient means 24, and while the wobbling forces on the other two wheels orthogonally Opposites are prevented hydraulically. Referring again to Figure 1, at some point along the length of each conduit, a fixed or adjustable valve may optionally be located to vary the degree of resistance to fluid flow through the conduits. These valves are marked 9b, 10b, 11b, 12b and are normally located between the smaller chambers of the cylinder and the branching or branch lines 9a ", 10a, 11a, 12a, which in turn may have additional limiters 9c, 10c, 11c , 12c located along their lengths Normally, in operation these valves allow a large volume of fluid to flow at low speed (like and during the articulation of the axle, while the valves restrict the flow of smaller volumes of fluid at higher speeds that are typical of the wheels that impact protrusions at speed and tend to disturb the smooth running of the vehicle. that for reasons of packaging it is sometimes preferable to have as few accumulators in the arc areas of the wheels as possible and therefore only one accumulator is indicated per hydraulic circuit although maximum comfort can be obtained by the incursion of a second small accumulator located near the lower chambers Ib, 2b, 3b, 4b In addition, with reference to the type of arrangement shown in Figures 1 to 7 (which allows additional resilience of the inclination as a direct result of the design the resilient medium within the load compensation units 13), it has been found that only a small volume of gas is normally required s in the accumulator associated with the lower chambers of the hydraulic cylinders. Figure 8 of the drawings represents the present invention applied to a vehicle in which the hydraulic rams 1, 2, 3 and 4 are individual action rams in contrast to the double action rams as described by reference to Figure 1. As a result of the rams that only act individually, each of the ducts 9, 10, 11 and 12 connects only the respective upper chambers, the, 3a, 2a and 4a of the rams with the chambers 14, 16, 15 and 17, respectively, of the load distribution unit 13. In this way, the portions of the ducts communicating with the lower chambers 3b, Ib, 4b and 2b of the hydraulic rams can be eliminated. The flow restrictors 9b, 10b, 11b and 12b placed in the remaining portions of the conduits 9, 10, 11 and 12 may be desirable to allow additional tuning of the suspension characteristics. Variable flow limiters can be equipped with a "semi-active" system evolution. Figure 8 also further illustrates modifications to the load distribution unit 13 that can optionally be included in the version shown in Figure 1. In Figure 8, outer rod portions 18a and 19b are now of different diameters to inner portions 18b and 19b. This may be necessary to create differential areas from one side of the piston to the other in order to compensate differential pressures of the system from the front to the rear, due for example to uneven weight distribution of the vehicle. The outer rod portions can be larger or smaller in diameter compared to the inner rod portions depending on the direction of the deflection, which in turn is dictated by the sequence of connection of the conduits to the load distribution unit. Figure 9 shows the same circuit arrangement as shown in Figure 8, but with the modifications that are restricted to the load distribution unit 13. While Figure 8, the outer rod portions 18a and 19a were of different diameters to the rod portions 18b and 19b, internally by the same reasoning, the outer, rod portions 18a and 19a could be omitted completely if desired . Depending on the weight distribution of a vehicle, it may be necessary to change the sequence in which the conduits are connected to the load distribution unit as mentioned above. In addition, the load distribution unit 13 as shown in Figures 1 and 2 has been modified in Figure 9 by replacing the pistons 18 and 19 in Figure 2 with a piston built substantially the same as the resilient member 20. as seen in Figure 2. Equivalents of the disk sections 18c and 19c are constructed which interspersed the resilient member 20 in Figure 2, to function as pistons having reciprocating movement in the chambers 13a and 13b in the same basic manner as the individual pistons as shown in Figures 1 and 2. However, the use of this construction of the pistons, which has the resilient intermediate section, results in some limited resilient movement between the two sections of the piston when one of the The wheels are subjected to a sudden shock load, in the same way as the load distribution unit 20, as previously described with reference to Figures 1 and 2. The movement during wobble will result, resulting in a reduction in the rigidity of the wobble with the configuration shown in Figures 8 and 9. Figure 10 shows an alternative, preferred, additional form of the load distribution unit 13. In addition to the chambers 14, 15, 16, 17 provided in the aforementioned forms of the distribution unit 13, the two piston assemblies 18, 19 are separated by a center chamber 35 containing a compressible gas or a fluid. An accumulator 38 communicates with the center cylinder 35 and the movement of the piston assemblies 18, 19 between each other will be prevented by the gas or fluid contained within the center chamber 35. The outer rod portions 18a, 19a are larger in diameter than the inner rod portions, 18b, 19b which are respectively accommodated within the outer chambers 33, 34. These outer chambers are connected by a conduit 36, with an additional accumulator 37 being provided in this conduit 36. The fluid is contained within the outer chambers 33, 34 and the connecting conduit 36, and the movement of the assemblies 18, 19 piston away from each other is prevented by the fluid contained therein. This load distribution unit 13 has the ability to control the tilt and accommodate large variations in the vehicle load. For example, if a significant load is added to the rear of the vehicle, the piston mounts 18, 19 of the load distribution unit 13 will be further pushed due to the increased pressure and volume of fluid in the interior chambers 15, 16 Of the same. To compensate for the increased load of the cameras 1516, inside, additional fluid can be introduced into the outer chambers 33, 34 by a pump 40 or other means to increase the pressure acting on the ends of the rod portions, 18a, 19a thereby allowing the pistons 18, 19 return to their correct operating positions despite the increased load of the vehicle. Conversely, when the piston assemblies move too close together, it may be necessary to release fluid from the outer chambers 33, 34 to the tank 41 to compensate for removing the vehicle load or for an added load on the front of the vehicle. Also, the fluid can be pumped or drained from the center chamber 35 to control the position of the piston assemblies 18, 19. The return of the pistons 18, 19 to their correct operating position allows a greater clearance for the movement of the piston assemblies to thereby prevent any restriction of the movement of the pistons 18, 19 within their respective cylinder portions. Therefore, for a pressure set in the center chamber 35 (ideally achieved through the use of a pressure regulating valve), the load distribution unit 13 can be controlled to compensate for changes in the load on the vehicle. To control the necessary flow of fluid to and from the alternative load distribution unit 13, a position sensor of the load distribution unit (preferably a Hall Effect sensor) is required to allow the position of each piston 18, 19 find out. In order to achieve the correct positioning of these pistons, an electronic control unit averages the signals from the piston position sensor of the load distribution unit to achieve the desired initial spacing between the pistons 18, 19 when supplying or releasing fluid from the piston. the outer chambers 33, 34. Additional details of this load distribution unit are described in International Applicant Application No. PCT / AU94 / 00646 and the details are incorporated herein by reference. As noted above, the suspension system according to the present invention tends to reduce the tilting movements of a vehicle when going over speed peaks or other obstacles, however, it is preferable to maintain the height of the rear of the vehicle towards up until immediately before the rear wheels impact the crest of speed and retract the rear rams as the rear wheels travel over the ridge. This helps to further reduce the tilt movement of the vehicle as it travels over these or other obstacles. To this term, a quick acting valve 42, such as a solenoid valve in the mouth of one or both of the accumulators 37, 38 of the load distribution unit 13 is provided. This valve 42 can be provided for example in the mouth of the accumulator 38 of the center chamber 35 as shown in Figure 10. As the gas or fluid enters the accumulator 38 when the front wheels hit a ridge and the fluid is expelled from the chambers 2a of the upper part of the front rams 1, 2 towards the load distribution unit 13, the solenoid valve 42 can temporarily close the accumulator 38 to store the gas or pressurized fluid. An electronic control unit can determine when the rear wheels impact the ridge and this has the effect of retracting the rear rams 3, 4 as the rear wheels travel over the ridge so that the tilt movement of the vehicle is further reduced, the energy absorbed for the rear axle.

Figure 11 shows the suspension system of Figure 1, which has been modified to incorporate a "load distribution shutdown or shutdown" arrangement. The applicant's suspension system has the advantage of allowing large degrees of "articulation" of the axle without significantly affecting the normal reaction force on each wheel of the vehicle to the ground, thereby maintaining a similar amount of traction on the extremely rough ground. or rough as on flat ground. The term "articulation" refers to the movement of diagonally placed wheels in a common direction. In addition, these systems oppose and thus limit the wobble movements of the bodywork created when the vehicle is taking a turn without the need for sway stabilizer bars. It has been found that in vehicles equipped with the suspension system noted above, during extreme situations, for example, when there is a combination of a very fast turn and hard braking or rapid acceleration, this may result in the lightly loaded wheel of the vehicle is completely lifted off the ground. While this does not necrily affect the overall stability of the vehicle, lifting one of the vehicle's wheels can be disconcerting. The load distribution closing arrangement includes at least one "stop or stop" valve 30a, 30b provided in at least one of the branching or bypass conduits 9a, 10a, lia, 12a. In the arrangement shown in Figure 1, the valves 30a, 30b are respectively provided in the branch ducts 9a and 11a communicating with the outer chambers 14, 17 of the load distribution unit 13. When the valves 30a, 30b are acting to block the flow of fluid through the branch lines, this acts to disable the suspension system, so that the articulation in the suspension system is restricted or prevented. This stops or minimizes the lift of the wheel under the extreme driving or driving conditions indicated above. These conditions can be determined via a sensor means mounted on the vehicle, the sensor means that drives the valves 30a, 30b.

The sensor means may include an acceleration sensor. Alternatively, or in addition, the sensor means may include a vehicle speed sensor. The sensor means may provide a signal to the control means when both lateral and longitudinal accelerations of the vehicle in excof the preset, programmable levels are detected simultaneously, the control means thereby actuating the closing means. The control means can only actuate the closing means when the signal from the vehicle speed sensor indicates that the speed is above a pre-set level. This prevents the actuation of the closing means when the vehicle is traveling rough rugged terrain. It should be noted that the sensor means can comprise many different types of sensors as long as the sensor means is able to determine from the available absorbed energies, the appropriate reactions for lateral and longitudinal accelerations acting on the vehicle. For example, the sensor means may alternatively consist of sensors for the position of the brake pedal and position of the intake handle, steering angle, speed. By using the resilient members 20 instead of the pistons in the load distribution unit 13 as shown in Figure 9, it is possible to eliminate the need for the accumulators 5, 6, 7, 8 in the suspension system this will be in generally the case for any of the embodiments of the suspension system according to the present invention. The load distribution unit according to the present invention provides the suspension system with additional resiliency in the direction of inclination of the vehicle while not increasing the docility of the vehicle in the wobble direction. This has the advantage that the front wheels are virtually "uncoupled" from the rear wheels when the front wheels impact a speed crest or other obstacles so that the rear wheels are not significantly influenced by the movement of the front wheels in this situation. This results in ldiscordant tilt movements of the vehicle and a smoother ride.

It is noted that in relation to this date, the best method known by the applicant to carry out the present invention, is the conventional one for the manufacture of the objects to which it refers. Having described the invention as above, the content of the following is claimed as property:

Claims (23)

1. A suspension system for a vehicle having a load-bearing vehicle body, and at least one pair of front wheels that engage the ground and at least one pair of rear wheels that engage the ground connected to the body of the vehicle to support At the same time, each wheel that can be displaced relative to the body of the vehicle in a generally vertical direction, the suspension system is characterized in that it comprises a hydraulic ram or double action cylinder interconnected between each wheel and the body of the vehicle, each ram including a first and second fluid-filled chambers that vary in volume in response to relative vertical movement between the respective wheel and the vehicle body, each front wheel ram that is connected to the rear wheel ram diagonally placed by a respective pair of fluid communication conduits, a first pair of ducts connecting the p The first chamber of the front wheel ram to the second chamber of the rear wheel ram and the second of the pair of pipes connecting the second chamber of the front wheel ram to the first chamber of the rear wheel ram, each pair of ducts and rams of the interconnected front and rear wheels, thereby constituting a respective closed circuit whereby a first and second closed circuits are formed, and a pressure distribution means interposed between the first and second closed circuits and adapted to achieve substantially the pressure equilibrium between the closed circuits, the pressure distribution means comprising two primary pressure chambers, each divided into two secondary pressure chambers by the force transfer means, the means of force transfer of the primary pressure chambers which is operatively interconnected by the interconnecting means for the transferring movement between these, and allowing the controlled independent movement to vary the relative position of the force transfer means in the primary pressure chambers, and provide resilience to additional resilience in a direction of inclination of the vehicle body in relation to a wobbling or rolling direction of the vehicle body.

2. A suspension system according to claim 1, characterized in that the secondary pressure chambers include a pressure chamber, secondary include an inner chamber adjacent to the interconnecting means and an opposite outer chamber, the outer chambers are respectively connected to the first conduit of each closed circuit, the inner chambers that are respectively connected to the second circuit of each closed circuit, the two secondary chambers of a primary pressure chamber that are respectively connected to the rams on one side of the vehicle body, the pressure chambers , secondaries of the other primary pressure chamber that are respectively connected to the rams on the other side of the vehicle body.

3. A suspension system according to claim 2, characterized in that the force transfer means of the respective primary pressure chambers are interconnected by the interconnection means adapted to allow axial, controlled, relative movement between the transfer means of force, with which differential movements of the front and rear wheels can be made in relation to the chassis.

4. A suspension system according to claim 3, characterized in that the interconnection means is effected by a resilient member.

5. A suspension system according to claim 3, characterized in that the interconnection means is effected by means of compressible gas.

6. A suspension system according to any one of claims 1 to 3, characterized in that each of the transfer means at the adjacent ends extends into a common chamber isolated from the primary pressure chambers, the common chamber being charged with a fluid to apply an equal force to each force transfer means.

7. A suspension system according to claim 6, characterized in that an accumulator is in operable communication with the common chamber for the flow of fluids therebetween.

8. A suspension system according to claim 7, characterized in that the operable communication is through a selectively variable flow velocity passage.

9. A suspension system according to claim 6, 7 or 8, characterized in that each force transfer means extends in a respective third chamber located on the opposite side of the primary pressure chambers to the location of the common chamber, the third chambers that are in altered communication for the flow of fluids between them.

10. A suspension system according to claim 9, characterized in that the operable communication includes an accumulator for the flow of fluids therebetween.

11. A suspension system according to claim 10, characterized in that the operable communication is through a selectively variable flow velocity passage.

12. A suspension system according to claims 9, 10 or 11, characterized in that means are provided for selectively supplying or withdrawing fluid from the third chambers ..

13. A suspension system according to any of claims 6 to 12, characterized in that means are provided for selectively supplying or withdrawing fluid from the common chamber.

14. A suspension system according to any of claims 6 to 13, characterized in that the fluid is a gas.

15. A suspension system according to any of the preceding claims, characterized in that means are provided for selectively isolating the pressure distribution means from at least one of the pairs of the fluid communication conduits.

16. A suspension system according to any of claims 9 to 15, characterized in that each of the force transfer means includes piston and piston rod portions extending from opposite sides thereof, a portion of rod. piston that fits inside the third chamber, the other portion of the piston rod that fits inside the common chamber.

17. A suspension system according to claim 16, characterized in that the diameter of a piston rod portion is different from the diameter of the other piston rod portion.

18. A suspension system according to any one of claims 1 to 3, characterized in that the means of interconnection between the two force transfer means includes a respective rigid member projecting from each force transfer means into an additional chamber. and the control pistons are attached to the respective control pistons therein, defining within the additional chamber a first control chamber between the two control pistons and on the opposite side of each of the respective second control chambers. of the control pistons, the first and the second control chambers each being loaded with a fluid to normally centralize the pistons defining the smaller chambers and to allow controlled movement between them to allow independent control of the inclination with this mode and wobble of the vehicle.

19. A suspension system according to claim 18, characterized in that the two control chambers are placed in a side-by-side relationship and the control pistons are each placed in respective chambers side by side.

20. A suspension system for a vehicle body having a plurality of wheels arranged in a spaced, lateral and longitudinal relationship to support the vehicle body, the suspension system is characterized in that it comprises individual action ram means, individual, arranged between each wheel and the body of the vehicle, each ram means including an individual chamber filled with fluid, a first and a second balancing or compensation means each having two chambers and a force transfer means that separates the chambers and that can be displaced in response to the pressure conditions in the respective chambers, the force transfer means of each equilibrium means that is operably interconnected by means of interconnection to transfer force between these to achieve a state balanced or compensated between the two means of force transfer; the two chambers of each balance means including an inner chamber adjacent to the interconnecting means and an opposite outer chamber; the interior chambers of each balancing means that are in fluid communication respectively with the ram chamber at one end of the vehicle, and the outer chambers of each balancing means that are in fluid communication, respectively, with the chamber of the vehicle. means of the ram at the opposite end of the vehicle body, such that both chambers of the first balancing means are in fluid communication with the ramming chambers of one end of the vehicle body, both chambers of the second balancing means which they are in fluid communication with the water ram chambers on the opposite side of the vehicle body; wherein the interconnecting means is resilient and adapted to transfer force and allow relative movement between the force transfer means to provide additional resiliency in a tilting direction of the vehicle body relative to a body wobble direction of the vehicle, and wherein the force transfer means are resilient to provide resilience in the wobble direction thereof.

21. A suspension system according to claim 20, characterized in that the first and second balancing means each comprise a main chamber divided by a resilient piston to form two chambers, each piston constituting a force transfer means.

22. A suspension system according to claim 21, characterized in that the piston includes opposite sides, the respective area side of each side thereof being different.

23. A suspension system according to any of the preceding claims, characterized in that it includes a means of damping to dampen the movement of the force transfer means. SUMMARY OF THE INVENTION A suspension system for a vehicle having a body and a plurality of wheels arranged in a spaced apart relationship, laterally and longitudinally, to support the vehicle body, and including individual double action rams arranged between each wheel and the vehicle body , and comprising a cylinder and a piston axially movable therein as a result of relative movement between the wheels and the vehicle body. Each front wheel ram is connected to the rear wheel ram, diagonally opposed by a respective pair of fluid communication conduits, a first of the conduits connecting the first ram chamber of the front wheel to the second ram chamber of the front wheel. the rear wheel and the second ram chamber of the front wheel to the first ram chamber of the rear wheel. Each pair of conduits and rams of the interconnected front and rear wheels, which thus constitute a respective closed circuit, whereby a first and a second closed circuit are formed. A pressure distribution means interposed between the first and second closed circuits, and adapted to achieve substantially the pressure equilibrium between the closed circuits. The pressure distribution means comprises two primary pressure chambers, divided into two pressure chambers, secondary by force means. The force means of the primary chambers are operatively interconnected by a resilient device arranged to transfer movement between the force means, and allow independent, controlled movement between them. Secondary chambers include an inner chamber adjacent to the interconnection of an opposite outer chamber, the outer chamber that is connected respectively to the first conduit of each closed circuit, the inner chambers that are respectively connected to the second circuit of each conduit, the two primary chambers of a primary pressure chamber which are respectively connected to the rams on one side of the body of the vehicle, the two primary chambers of the other primary pressure chamber which are respectively connected to the rams on the other side of the body of the vehicle.