DUAL DRIVE ARRANGEMENT FOR THE DRIVE OF A VEHICLE HYDRAULIC PUMP AND METHOD OF CONTROLLING THE SAME

摘要

The dual drive arrangement has three way power split device such as an epicyclic gearing system (3) converting input rotation from a gearbox (5) or from an electric motor into an output rotation driving the hydraulic pump (2). The method for controlling the dual drive arrangement driving a hydraulic pump (2) comprises the steps of: setting a minimal flow value Qm to the hydraulic pump (2); sensing the vehicle speed processing the sensed vehicle speed where the processing comprises comparing the sensed vehicle speed with a reference speed value to thereby determine whether the vehicle operates in a first operational mode I where the speed vehicle is too low to drive the hydraulic pump (2) up to the minimal flow or in a second operational mode II where speed vehicle where the speed vehicle is sufficient to meet at least the minimal flow value Qm; controlling the operation of the epicyclic gear so that the electric source drives the hydraulic pump (2) when the vehicle runs under the first operational mode I and at least the gearbox drives the hydraulic pump (2) when the vehicle runs under the second operational mode II.