Dynamic Characteristics of Pressure Compensator in Underwater Hydraulic System

A pressure compensator for an underwater hydraulic system is studied in this paper. The compensator is used to maintain the tank pressure of the underwater hydraulic system so that it is slightly greater than the ambient pressure, allowing the system to work at any depth. The dynamic characteristics of the pressure compensator are studied using theoretical analysis, simulation and experiment. The tank pressure changes due to the step flow to the tank coming from the motion of a piston in a single-rod cylinder. This flow is caused by the unequal areas of the piston. The tank pressure change can be mathematically determined. A design procedure focusing on the dynamic characteristics of the pressure compensator is given. A compensator and underwater hydraulic system were built and the dynamic characteristics of the compensator were tested. Both simulation and experimental results conform to the analysis. The study provides a theoretical way to determine the dynamic characteristics of a pressure compensator in an underwater hydraulic system.