Design and Simulation Analysis of Hydraulic Retraction and Extension System for Landing Gear of High-Speed Superconducting Electrodynamic Suspension Train

The performance of the landing gear hydraulic retraction and extension system (LGHRES) directly affects the safety of high-speed superconducting electrodynamic suspension train, and is one of the important indicators for evaluating the quality of train operation. The LGHRES is designed and simulated. Based on the overall technological parameters, around the design goals of the LGHRES, the function and configuration of the LGHRES are determined, the schematic diagram is designed, the function planning and the theoretical calculation of the key parameters are completed. The simulation analysis of the designed LGHRES by AMEsim shows that: (1) the error between the accumulator initial charging time and the theoretical calculation is less than 1%. (2) When the accumulator is at the minimum normal working pressure of 17.5 MPa and the hydraulic pump is no longer working, the accumulator can be used for two emergency retraction and extension cycles of liquid storage. (3) By adjusting the flow area of the proportional directional valve from 5 to 20 mm2, the requirement of adjusting the landing gear retraction or extension time within 5 to 10 s can be achieved. (4) When the diameter of the flow hole of the accumulator unloading solenoid valve is between 5.5 and 6.0 mm, it can meet the requirement of a discharging time of 20 to 30 s for the accumulator.