Design and experiment of novel piezoelectric double nozzle flapper electro-hydraulic servo valve

To improve the performance of the existing nozzle flapper type electro-hydraulic servo valve, a novel piezoelectric double nozzle flapper electro-hydraulic servo valve (PDNFESV) is proposed. An electricity-machine transducer is designed to replace the torque motor in the traditional nozzle flapper servo valve. The electricity-machine transducer is constructed by two identical piezoelectric bimorphs and a beryllium bronze board. The design and fabrication of the electricity-machine transducer is introduced. The structure and work principle of the novel PDNFESV is analysed. The static and dynamic characteristic of the electricity-machine transducer are tested, the experimental results show that the designed electricity-machine transducer can meet the demand of the novel PDNFESV. At last, the performance indexes of the novel PDNFESV are researched.