Abstract:To obtain the dynamic parameters of direct-driven super pressure pumps, an experimental modal analysis has been made of the overall structure of direct-driven pumps. The frequency response function is optimized based on the analysis of the experimental data, and a single-mode parameter identification method has been adopted to identify the parameters of direct-driven pumps, thus obtaining the machine inherent frequencies, damping ratio, and the corresponding mode shape. The research results show that the inherent frequency of super pressure direct-driven pump mainly concentrate in the low frequencies (49.90, 100.21, 149.13, 175.93 Hz) and high frequency (with a high mode frequencies above 1 000 Hz); while the weak links mainly concentrate on the valves. During the operating process of direct-driven super pressure pumps, three ranges of speed, 981.8, 2 004.2, and 2 982.6 r/min should be avoided by the motor speed.