Stator core, manufacturing method therefor, and rotary electric machine that uses that stator core

A method for manufacturing a stator core in which teeth respectively extend radially inward from an inner circumferential surface of an annular core back and are arranged at a predetermined pitch circumferentially,

• said method for manufacturing a stator core comprising:
• a punching step in which magnetic segments that have a core back portion and tooth portions are punched out of an electromagnetic steel sheet that is coated with an organic insulating coating;
• a laminating step in which a laminated body is formed by laminating a predetermined number of said punched magnetic segments such that said core back portions and said tooth portions are respectively stacked on each other;
• a first preheating step in which a welding position on a wall surface on an opposite side of said stacked core back portions of said laminated body from said tooth portions is heated locally from a first end to a second end in a direction of lamination to decompose an organic component in said insulating coating thermally at said welding position;
• and
• a first welding step in which said welding position at which said organic component in said insulating coating is decomposed thermally is welded from said first end to said second end in said direction of lamination to interconnect and integrate said laminated magnetic segments.