A pump located under the injection unit, with internal gear driven by an electric motor of very small size, provides for the recharge of the accumulators. The accumulators act as “energy dam” : once the required filling level has been reached the motor shuts off to minimize power consumption. The motor is controlled by a dedicated inverter thus maximizing the efficiency of the system. This system allows speed performance on the injection axis otherwise impossible and the possibility of overlapping ejection and core pullers to all other movements for faster cycles. The advantages of this application are: reliability, high performance, high precision, energy savings, flexibility of the system.