MOTOR CORE WITH SMALL IRON LOSS DETERIORATION UNDER COMPRESSIVE STRESS

摘要

PROBLEM TO BE SOLVED: To provide a motor core in which deterioration of high frequency iron loss characteristics is small even in the presence of compressive stress.SOLUTION: In a motor core, a magnetic steel sheet which preferably includes a component composition containing 7 mass% or less of Si, 3 mass% or less of Al, 5 mass% or less of Mn, 0.01 mass% or less of S, 0.005 mass% or less of N and 0.01 mass% or less of O and to which an insulation coating is applied is laminated, and 10 MPa or more of compressive stress is applied to the circumferential direction. A back yoke part of the magnetic steel sheet constituting the motor core is irradiated with electron beams at 0.2-5 mm of intervals.