Static stress and modal analysis of water hydraulic reciprocating piston pump driven by the linear motor

In recent years, with the mature of linear motor technology, linear motor has been more and more widely applied in the field of hydraulics. The water hydraulic reciprocating piston pump driven by linear motor has the advantages of constant flow and low vibration. Compared with traditional piston pump which can only regulate the movement of the pump by means of rotor speed control, the water hydraulic pump can get a good flow output performance through servo control. For the large flow bilge pump used in naval ships, this paper use a novel four double-action linear motors to drive eight pistons. In this research, the system simulation model is established, and the static stress analysis and modal analysis are conducted. As a result, we obtain ten orders natural frequency and amplitude of the system, and then discuss the different position of vibration situation when a damping module is added in the system. The lowest frequency of the system is close to 1507 Hz, which is much large than the motion frequency. And with added the damping module, the lowest maximum deformation is reduced to 4 mm and occurs on cylinder joint. The research work provides an effective method to analyze the vibration of the water hydraulic reciprocating piston pump driven by linear motor. It is suitable for further dynamic analysis and structure optimum design to reduce the vibration of the water hydraulic piston pump.