HPS (Hydro Pneumatic Suspension) is a hydropneumatics suspensions system installable on motor vehicles with capacity up to 35t.
This type of suspension is out of classical schemes to which we are accustomed to, it is specifically suitable for all the vehicles that need greater comfort compared to the series constructive standard, in fact, this suspension acts on the synergy between a hydraulic system and a pneumatic one. Installable exclusively on the rear axle, it is based on the work of two hydraulic actuators (similar to common jacks) that replace the series shock absorbers.

These, in turn, are connected through high pressure tubes to a hydraulic pump that manages the quantity of oil inside the same actuators, consequently adjusting the vehicle’s height off the ground.

Instead, the elasticity of the suspension remains constant, since the shock absorbing function is executed by pressurised hydrospheres, inside which circulates oil kept in constant pressure by a chamber containing preloaded nitrogen.

This system has both the shock absorbing function and the vehicle load bearing one. Practically, it executes a stabilizing effect (usually given by the common hydraulic shock absorber) and a vehicle height adjusting effect (usually given by leaf springs or springs).

The HPS system also has two great advantages:

  1. It allows the vehicle on which it is installed to maintain a constant height from the ground, regardless the weight of the load transported or type of ground that vehicle travels on. This occurs automatically since the appropriate electronic control unit manages everything.

  2. It allows remarkably improving the driving comfort of the vehicle, making all the solicitations of the body and passenger compartment, transmitted during travel, almost imperceptible.

Currently, the HPS system is installed exclusively at the O.M.A. headquarters, since the assembling may require subjective modifications and adequate software programming.

The HPS system is totally self-levelling, in fact, it is equipped with height detectors that control a particularly advanced electronic control unit that allows also the levelling between the right and left side of the vehicle, recovering differences in level often due to an ununiformly distributed load on the vehicle floor.

The parameters of the control unit are customisable according to the different needs of the users. These are preset at the moment of installation, through proper software that also allows a rapid check-up in case of HPS suspension malfunction. The only operation allowed manually regards the complete lowering of the vehicle through appropriate digital pushbutton installed on the dashboard. This operation is useful to facilitate the loading of materials or persons (obviously with vehicle stopped).

As soon as the motor vehicle is restarted, the suspension automatically returns to the preset height, whatever the variation of the load may be. Thanks to its practical use and its effective yield, HPS is particularly indicated on medical vehicles and rescue means, such as ambulances or vehicles for the transportation of disabled persons.

HPS is available for the following mechanics: Fiat Ducato X250, X290, Peugeot Boxer, Citroen Jumper.