A prototype of an active cab suspension has been realized and successfully tested. Especially in the frequency range around 2 Hz a marked reduction of cab vibrations has been achieved. At frequencies beyond 5 Hz the performance is not satisfying. An analysis of the hydraulic components available at present shows that trying to increase the upper frequency limit is not very effective, because then complexity and energy demand grow more than proportionally. Therefore, as alternative, a hybrid suspension system is described that can be realized and operated at moderately low costs and has a good vibration isolation over the whole frequency range. By systematically saving hydraulic energy it seems possible to realize a power supply from axle vibrations. Because then energy supply and energy need go in parallel, losses during phases of low demand are avoided which increases life of the control elements definitively and cooling systems can be omitted. (A)
Samenvatting