Suspension (Hydragas suspension): Description and operation

HYDRAGAS SUSPENSION

The Hydragas suspension system consists of a Hydragas unit at each wheel, mounted vertically between the vehicle’s body and top suspension arm. The units are connected front to rear at each side of the vehicle via pipes, and pressurized with fluid. This method of linking the units improves the vehicle’s resistance to pitch. The pitching motion occurs when the front suspension is compressed and the rear suspension is extended simultaneously.

Controlled distribution of the fluid between the two connected units combats the pitching motion. A sudden upward movement of the front wheel displaces fluid from the front hydragas unit, forcing it through the connecting pipe into the rear unit. This action raises the rear of the vehicle to the same level as the front, keeping the vehicle’s body horizontal. When the front wheel descends the fluid is returned and the suspension settles to its normal position.

The hydragas system also restricts vehicle roll when cornering, this is achieved by the two outside units stiffening when under load.

Each Hydragas unit comprises of two chambers separated by a rubber membrane. The upper chamber which is sealed contains nitrogen gas, the lower chamber is filled with a water base fluid containing approximately 50% alcohol to prevent freezing, and a corrosion inhibiter.

Damping is achieved by fluid passing through a two-way valve arrangement restricting the flow of fluid in the unit. One valve provides bump control and the other restricts rebound.