基于气隙组合永磁弹簧的直动式溢流阀优化设计

The characteristics of aerospace servo system with high pressure and large flow put higher requirements on the reliability, precision and the thrust weight ratio of relief valve. However, the spiral compression spring with large thrust is generally large, and there are some failure modes such as stuck, fatigue fracture and plastic deformation during the service period, which brings hidden safety troubles to the servo system. A direct relief valve structure with air gap combination of permanent magnet spring is presented. The above-mentioned failures can be avoided because of non-contact permanent magnetic spring. By optimization design of air gap combination the ideal stiffness curve and thrust weight ratio can be effectively improved. Besides, the pressure fluctuation at opening due to large stiffness is reduced at the same time. Furthermore, the flange structure is designed accurately by finite element analysis to compensate the hydrodynamic force. The stabilized pressure precision is further improved. The simulation results show that this novel relief valve has good dynamic and static performance, and its design method provides reference for the application of the permanent magnet spring in the hydraulic system.