Abstract: The invention relates to a driving unit for a feed pump, particularly for a crude oil feed pump which is suitable for recovery of energy. The delivery flow of a hydraulic variable displacement pump, in particular a pump of the axial piston type is used to perform the upstroke of the pump piston. A directional valve control means is provided to deliver the liquid volume displaced under pressure in the downstroke of the pump piston through the pump in the same direction of flow as for the upstroke. The pressurized fluid may either pass to a reservoir, wherein the pump drives a motor for supplying electrical energy back to the electric supply, or, respectively, may load a hydraulic accumulator which is connected to the suction port of the pump for performing the upstroke of the pump piston for which the accumulator is discharged, wherein the remaining torque only has to be supplied by the drive motor.