A transmissibility-based approach to identifying the dynamic behavior of a seawater hydraulic piston pump under pressure excitation

An investigation into the dynamic behavior of the piston pump is an important method to reduce its vibration and noise. In this paper, an approach to predict the dynamics of a seawater hydraulic piston pump (SWHPP) from output-only transmissibility measurements is introduced. In order to eliminate the harmonic interference generated by spindle rotation, the excitation in this method is the pressure which caused by the SWHPP operating at a constant speed and under different loading conditions. The first four modes of the SWHPP were estimated utilizing the method proposed in this paper, and the influence of the pressure on the dynamics of the SWHPP structure was further studied. The experimental results indicated that peak occurred around the frequency of 20 Hz, and the reason is that the estimated second-order natural frequency (19.8 Hz) is near to the frequency of 20 Hz which is the excitation frequency of the swash plate and the flat valve of the SWHPP. In addition, this method can identify modal parameters of the piston pump structure in the working state, so it can effectively predict the dynamic behaviors of the piston pump.