Study On Spool Valve Overlap Value Of Servo Valve Measuring System Based On Weighting Method

The measurement of spool valve overlaps of a servo valve is a key processingtechnique of servo valve manufacturing that is widely used in a large number ofapplications in the field of aerospace, such as hydraulic servo control systems. Theoverlap value is the main valve port processing quality control indicator whichdirectly affects the overall power performance of the spool valve. The existingmeasurement of servo valve flow is based on the application of gear flow meterwhich can meet applications demand but its high cost and production errors due toits working principle leave room for improvement. On the other hand, the use ofweighing method, especially for low flow measurement, not only reduces thedisadvantage of the gear flow meter, but also the cost.This thesis firstly discusses the background of the servo valves spool overlapsmanufacturing, then it analyses the theory of servo valves overlaps flowmeasurement and the principles of the weighing method. Secondly, the thesis givesdetailed design of each part of the system in line with the overall design of the flowmeasurement system by the weight, which includes: the remolded hydraulic part;the mechanical part; the electrical part; the computer interface and the controlsoftware. Finally, after the system debugging, the thesis provides the experimentscheme, results and the data collection and handling. After calculating the servovalves overlaps and analyzing the outcome of the experiment, this thesis comes tothe conclusion that: the system meets the design requirements and, the measurementof servo valves overlaps automatically based on weighing method to replace theexisting use of gear flow meter is feasible. This means this method has greatresearch value.