This product is consisfed a main pump using in closed circuit and an auxiliary pump using in open circuit.The main pump is axial piston,variable displacement pump of swashplate design,achieving three operating positions(positive,negative and zero) through a three-way four-path elecfromagnetic value.The main pump also includes an integral charge pump to provide system replenishing and cooling oil flow,as well as servo coufrel oil flow to vary the displacement on the main pump,The auxiliary pump is designed as a gear pump to provide flow to other system.This product is a compact struction,high power deusity and suitable for engineering mechanis of road roller.