The stator winding has winding assemblies that are disposed in a stator core so as to be stacked in three or more layers in a radial direction such that slot-housed portions line up in single columns in a clot depth direction inside slots, and radial widths of return portions of the winding assemblies that are mounted so as to be stacked in a radial direction are made sequentially narrower in order of return portions of a winding assembly that is positioned centrally, return portions of a winding assembly that is positioned on an inner circumferential side, and return portions of a winding assembly that is positioned on an outer circumferential side.