3-D magnetic field analysis of hydraulic servo valve torque motor with magnetic fluid

As a functional material, magnetic fluid (MF) is filled in the working clearances of torque motor in hydraulic servo valve. The construction and working principle of torque motor with magnetic fluid are introduced. Using 3-D magnetic field finite element analysis (FEA) method, the magnetic field distribution and characteristics of torque created by the torque motor are analyzed. Calculation results are given. The torque characteristics are compared when magnetic fluid is filled or not in the torque motor. Compared with analytical method, 3-D finite element analysis method is accurate enough to calculate the output torque of torque motor