A Consideration of Magnetic Materials for a High Response Type LDM

Abstract

The yoke of a Linear DC motor (LDM) was made of a carbon steel (annealed S15C) in high speed hydraulic valve using a LDM, which was developed the authors. The paper deals with a consideration of seven magnetic materials for the LDM, which may be used in the future, the conclusion as follows: (1) In the case of flux density, B, of 1.0 tesla, annealed carbon steel, S10C, has the field strength, H, of 100%, the relative permeability, μ_r, of 95% and the hysteresis loss, W_h, of 120% compare with annealed carbon steel, S15C, as the standard, among four carbon steels. (2) Annealed spheroidal graphite, FCD450, has H of 200%, μ_r of 41%, and W_h of 59% compare with S15C, among two iron castings. The value of W_h was the minimum among seven materials. (3) In the case of free-cutting pure iron has H of 88%, μ_r of 102%, and W_h of 78% of S15C. The values of H and μ_r exceeded S15C, and it was the best material in the seven.