ELECTROMAGNETIC STEEL SHEET FOR ROTOR CORE, AND ROTOR

摘要

PROBLEM TO BE SOLVED: To provide a rotor core that has shrink-fitting fastening force causing no slip between a rotor core and a rotor shaft due to starting torque when an electromagnetic steel plate for a rotor core and the rotor shaft are joined together by shrink fitting without performing secondary processing such as shaping processing.SOLUTION: An electromagnetic steel sheet 4 for a rotor core has a punched through hole formed in a center part of a plate surface, and the ratio of the area of a shear surface 7 to the area of an end face 5 of the through hole is 50 to 90%. Further, the ratio of the area of the shear surface 7 to the area of the end face 5 of the through hole is preferably 70% or larger.