Abstract
High-speed and high-precision hydraulic valves have been widely required in the industry. The authors have been developed the hydraulic servo valve (LSV) using a linear DC motor (LDM). This paper describes a design method of the magnetic circuit and the optimization of the electrical time constant on a moving-magnet-type LDM. The electrical and mechanical time constants of the LDM are required to have small values so as to realize a high-speed-response LDM. The expressions of the electrical and mechanical time constants of the LDM is derived using the permeance method. These constants are also computed using the finite element method (FEM) combined the electric circuit equations. The measured electrical time constant is 10.5ms. The calculated values of the electrical time constant obtained by the permeance method and the FEM are 13.4ms and 10.2ms, respectively. It is clarified that two methods are useful for calculating the electrical time constant of the LDM.
