Manufacturing method for stator winding coil

A manufacturing method for a stator winding coil that is formed into a U shape, the stator winding coil including

• two rectilinear portions that are configured to be inserted into two slots that are formed on a stator core such that longitudinal directions thereof are oriented in an axial direction and
• a coil end portion that links together end portions of said two rectilinear portions,
• wherein said manufacturing method comprises:
• coating a jointless continuous conductor wire with insulation;
• forming a bulging portion on the jointless continuous conductor wire;
• forming oblique portions on said conductor wire at two longitudinal ends of said bulging portion;
• forming the two rectilinear portions on said conductor wire at opposite ends of said oblique portions from said bulging portion, the bulging portion being formed at a central portion between the two rectilinear portions and a pair of oblique portions linking the two linked rectilinear portions and the bulging portion;
• forming a crank portion on a central position of said bulging portion after forming said two rectilinear portions, the crank portion displacing radial positions of the two linked rectilinear portions by a set amount at the central position;
• and
• forming said oblique portions into a circular arc shape that is centered around a central axis of the stator core after forming said two rectilinear portions,
• wherein forming said crank portion includes holding a portion of said conductor wire at a first end of said bulging portion in a direction that is perpendicular to a direction of displacement of said crank portion by a first metal die that enables movement in said direction of displacement of said crank portion, and holding a portion of said conductor wire at a second end of said bulging portion in a direction that is perpendicular to a direction of displacement of said crank portion by a second metal die that enables movement in said direction that is perpendicular to said direction of displacement of said crank portion, and then forming said crank portion by moving said second metal die toward said first end in said direction that is perpendicular to said direction of displacement of said crank portion while moving said first metal die in said direction of displacement of said crank portion.