Hamm has launched its HD+ 90i PH hybrid tandem roller to market.
The new roller combines a conventional internal combustion engine (ICE) with a hydraulic accumulator – basic loads are handled by the diesel engine, while the hydraulic accumulator is able to ensure heavy loads are managed.
A Hamm spokesman said, “The underlying concept is based on the realization that although the maximum load is called for regularly while compacting, it is always just for a few seconds at a time. This typically occurs when starting up or activating the vibration or oscillation, for example. All other compaction tasks call for significantly less power. This is why we have equipped the power hybrid roller with a smaller diesel engine in combination with a hydraulic accumulator to satisfy the load peaks.”
Working like a pumped storage power station, as soon as the power demand falls below the maximum load of the ICE, a pump begins to fill the hydraulic accumulator. If a lot of power is required, the hydraulic system functions as an auxiliary drive and supplies a maximum short-term load of up to 20kW.