Analysis of Zero Deviation Fault of a Certain Type of Electrohydraulic Servo Valve

The engine guide vane control device is an important driving component of the engine anti-surge regulation system; it receives commands from the engine electronic controller and achieves the purpose of engine anti-surge by controlling the angle deflection of the guide vane. Aiming at the zero bias fault of electro-hydraulic servo valve of a guide vane control device, through analzing the operating principle of the guide vane control device, causes of the zero bias fault are analyzed, and the electro-hydraulic servo valve zero bias fault tree analysis is established. After investigating the underlying events one by one, and conducting the product breakdown inspection and experimental verification, it is ultimately determined that the zero deviation fault is due to the excessive protrusion of the limit screw causing the armature to collide and deform, resulting in the zero deviation of the electro-hydraulic servo valve exceeding the tolerance. By adjusting the protrusion of the limit screw and conducting the improvement measures under the simulated product performance testing conditions, the zero deviation anomaly disappears. The fault analysis method and results in this article have positive guiding significance for troubleshooting the similar faults in the external field, and have reference significance for improving the design of the similar products and developing new research products in the future.