ANALYSIS OF A TWIN-GAS-CHAMBER HYDRO-PNEUMATIC VEHICLE SUSPENSION

A hydro-pneumatic suspension strut concept with integrated two gas chambers is proposed to realize nearly symmetric stiffness properties in compression and rebound, and progressively hardening roll stiffness characteristics. Fundamental stiffness properties of the proposed strut suspension are compared with the suspension involving one-gas-chamber struts with an anti-roll bar, in terms of suspension rate and roll stiffness. Dynamic responses are performed under a range of road inputs and vehicle velocities, and an excitation arising from a steady turning maneuver. The simulation results of stiffness properties indicate that the suspension rate of the twin-gas-chamber strut suspension can be designed to achieve soft vertical ride around static ride height and progressively hardening properties in both compression and rebound, which could help realize hardening effects in roll stiffness, compared with the softening effects in roll stiffness characteristics of suspensions with one-gas-chamber struts or commercial air springs. The dynamic responses demonstrate that the twin-gas-chamber strut suspension could considerably enhance the roll performance of heavy vehicles and slightly improve suspension travel responses, with negligible influence on vertical and roll ride.