Influence of Magnetic Reluctances of Magnetic Elements on Servo Valve Torque Motors

作     者：LIU Changhai JIANG Hongzhou 

作者机构：School of Mechatronics EngineeringHarbin Institute of Technology 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2016年第29卷第1期

页      面：136-144页

核心收录：

学科分类：080704[工学-流体机械及工程] 08[工学] 080401[工学-精密仪器及机械] 0807[工学-动力工程及工程热物理] 0804[工学-仪器科学与技术] 

基　　金：Supported by National Natural Science Foundation of China(Grant No.50975055) 

主　　题：servo valve torque motor magnetic reluctance electromagnetic torque constant magnetic spring stiffness 

摘      要：The current research of electro-hydraulic servo valves mainly focuses on the vibration, pressure oscillating and source of noise. Unfortunately, literatures relating to the study of the influence of the magnetic reluctances of the magnetic elements are rarely available. This paper aims to analyze the influence of the magnetic reluctances of the magnetic elements on torque motor. Considering these magnetic reluctances ignored in previous literatures, a new mathematical model of servo valve torque motor is developed and proposed based on the fundamental laws of electromagnetism. By using this new mathematical model and the previous models, electromagnetic torque constant and magnetic spring stiffness are evaluated for a given set of torque motor parameters. A computer simulation by using AMESim software is also performed for the same set of torque motor parameters to verify the proposed model. The theoretical results of electromagnetic torque constant and magnetic spring stiffness evaluated by the proposed model render closer agreement with the simulation results than those evaluated by the previous models. In addition, an experimental measurement of the magnetic flux densities in the air-gaps is carried out by using SFL218 servo valve torque motor. Compared with the theoretical results of the magnetic flux densities in the air-gaps evaluated by the previous models, the theoretical results evaluated by the proposed model also show better agreement with the experimental data. The proposed model shows the influence of the magnetic reluctances of the magnetic elements on the servo valve torque motor, and offers modified and analytical expressions to electromagnetic torque constant and magnetic spring stiffness. These modified and analytical expressions could provide guidance more accurately for a linear control design approach and sensitivity analysis on electro-hydraulic servo valves than the previous expressions.