Research on the Vibration Characteristic of a Seawater Hydraulic Piston Pump System and Vibration Reduction Approach

Seawater hydraulic piston pump has been widely used in ocean engineering and become a key power component for underwater equipment due to its inherent characteristic such as energy conservation and environment friendly. As one of the most important properties of seawater hydraulic piston pump, vibration would further determine the stability, reliability and stealth of underwater equipment. In this paper, the dynamic of a novel crankshaft seawater piston pump with gearbox are analyzed theoretically, illustrating the dramatically effect of the gearbox on the vibration characteristic of the seawater hydraulic piston pump. Then, a new type crankshaft seawater hydraulic piston pump system driven by a permanent magnet synchronous motor instead of asynchronies motor is proposed in order to eliminate the gearbox and improve the vibration characteristics. In addition, the vibration characteristic of this new type crankshaft seawater hydraulic piston pump system driven by asynchronous motor and permanent magnet synchronous motor are studied and compared experimentally. The experiment results indicate that the seawater hydraulic piston pump system driven by permanent magnet synchronous motor eliminating the gearbox has lower vibration acceleration level in comparison with the pump system driven by asynchronous motor and gearbox. The vibration acceleration level can be reduced from 7dB to 4.3dB. Driving the seawater hydraulic piston pump by permanent magnet synchronous motor instead of asynchronous motor is of benefit to eliminating the gearbox and reducing the vibration excitation source. Consequently, the vibration characteristic of the seawater hydraulic piston pump system driven by a permanent magnet synchronous motor is significantly improved.