Accumulator for Energy Storage and Delivery at Multiple Pressures

Many of the hybrid power systems under development for use in vehicles offer a means for recapturing “wasted” vehicle energy. One of the best-known examples is the hybrid electric vehicle which couples the vehicle’s drive system to generators that store the electricity produced during deceleration in batteries. Another system with great potential is the hybrid hydraulic system which proposes an accumulator to store energy for later use. UW–Madison researchers have developed an accumulator that provides an exceedingly simple and elegant solution to the limitations of prior accumulators. Specifically the potential energy stored in the primary chamber of this accumulator can be delivered to the system pressure line at a variety of output pressures.


1) Greatly enhances the feasibility of hybrid fluid power systems as well as other hydraulic systems using accumulators 2) Cost-effective means of achieving multiple pressures in hydraulic systems 3) Can deliver and store potential energy at a far wider range of pressures than the accumulators of the prior art 4) Provides three or more alternate pressure levels in a single unit 5) Occupies far less space 6) Requires far less material 7) Installation costs are cheaper

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