Study of a Novel Axial Piston Pump with Adjustable Tilting Piston

In pump-control system, the flow rate is controlled by the rotating rate of pump or the displacement of the pump. The fixed displacement axial piston pump is designed for the rated operating condition. Therefore, the volumetric efficiency becomes worse when the rotating rate becomes lower. The variable displacement axial piston pump has a pilot valve to control the displacement. Thus, its structure is more complicated and its size is larger than the size of fixed displacement pump. In the proposed paper, a novel axial piston pump is introduced to alleviate these problems. An adjustable tilting mechanism for piston is utilized to switch the cylindrical barrel of pump to the conical barrel in order to enlarge the displacement of pump when the rotating rate of pump is lower. The displacement increases when the rotating rate decreases automatically. Compared with the variable displacement pump, the displacement of the novel axial piston pump can be changed without pilot valve. The novel axial piston pump has the same size as the fixed displacement pump. Besides, the volumetric efficiency of the novel axial piston pump is better in low rotating rate condition. The simulation model of the novel axial piston pump is constructed based on AMESim. Compared with the original axial piston pump, the novel one can compensate the increasing of volumetric efficiency loss at low speed.