Here's a bit from their
website:
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General Description
The Sachs Nivomat is a compact device for vehicle level control, containing all necessary system elements (supporting element, pump, accumulator, reservoir, regulator, etc.) in one housing. The Nivomat is installed instead of a conventional shock absorber, spring shock absorber or spring strut and automatically establishes the optimum vehicle level under all load conditions.
The Nivomat also takes over the spring and damping function. The installation of the Nivomat is usually carried out at the rear axle of a vehicle.
The specific characteristic of the Nivomat level control system lies in the fact that the energy necessary for adjusting the optimum height level is generated by the relative movements between the axle and the vehicle body arising from road irregularities while driving.
This means that – in contrast to other systems – the Nivomat operates without any pollution since it does not need any external energy supply.
Depending on road conditions, a vehicle with maximum payload reaches its normal ride-height after just a few hundred meters. As soon as the vehicle begins to move, the increasing power of the Nivomat (which comes from increased pressure) is used to elevate the vehicle body to a constant level. In this way, optimal driving performance is achieved.
In the vehicle, the Nivomat takes on the functions of a load-sensitive spring and a shock absorber.
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