The Romanian concept of active suspension with pneumatic actuators is in patent application OSIM-A/00368/28.05.2015 and was in PCT/EP2016/061515_23.05.2016 and is able to large static and dynamic car trim adjusting, assuring thus:
• ground clearance increasing on bad road to protect the passengers and the car;
• decreasing the ground clearance on speed road, to increase stability and cruise speed;
• increasing longitudinal and transverse stability by adherence increasing due to improved contact wheel ground
• increasing body stability and so the comfort but the same reducing turbulence round the car decreasing drag resistance and thus fuel consumption and pollution
• optimal positioning towards longitudinal and transverse axis, to reduce the turbulence round the car, especially under body, to decrease aerodynamic resistance and thus fuel consumption and pollution, but the same to reduce the lift force, increasing thus the adherence and stability;
The novelty and main advantages of the solution are:
A. Pneumatic actuators which can be applied to any kind of usual shock absorbers – Table 1, by replacing the dust shield made from plate/ rubber/ plastic , with a pneumatic cylinder (12b), whose lid is mounted on rod and sealed against it by a seal element (17), the cylinder being sliding sealed by one or more seal/s (11) placed in a circular trough made in an annular body (9) fastened against the outer cylinder of the shock absorber, a quick valve (15) fitted in a bore of cylinder provide air/gas filling, by coupling to a gas/air source.
Table 1 shows the proposed actuators comparative to the known pneumatic actuators made by bellows or sleeves. Both solution presented, have prices over $1000/set, but buoyant forces limited by reduced working pressure (under 9 bar), the Romanian solution reaching tens of bar, reducing the size and have prices under $200/set.
Table 2 shows versions with supplementary metallic spring having the role of take the vehicle weight and position it in the lowest position, the actuators having only the role of correcting clearance. The equipment is endowed with pressure and displacement transducers (with rod, without contacts, wired)
The solution was tested successfully on rigs and on the car.
B. The pneumatic active system with two pressure circuits – Table 3 uses one of high pressure circuit for filling the actuators for vehicle rising and one of low pressure for discharging the actuators pressure for vehicle descending, so the energy consumption is for the compressor maintain the pressure difference between the circuits.
Comparative to known active solution the proposed one is more compact, cheaper and easier realized.
The reduced price and its simplicity give a good marketability in a large range of application from the luxury and off road cars to the medium class cars.