Stator, method for manufacturing stator, and motor

A stator, comprising:

• a stator core having an annular portion and plural teeth that protrude radially outward from an outer periphery of the annular portion, the annular portion and the plural teeth being integrally formed with each other, the annular portion having a cylindrical shape;
• a molded coil that has an air-core portion into which the teeth of the stator core are inserted and that is stored in a slot formed between the teeth of the stator core;
• and
• a yoke that covers a circumference of the molded coil stored in the slot of the stator core, wherein
• the molded coil has an arc-shaped cross-section,
• the molded coil includes a resin-molded portion and an exposed portion exposed at the molded portion,
• the resin-molded portion comprises:
• an air-core coil having the air-core portion at a center of the air-core coil;
• a first resin covering a portion of the air-core coil;
• and
• a second resin covering an entire periphery of the air-core coil including other portions not covered with the first resin,
• the air core coil has an arc-shaped cross-section which has an outer arc surface, an inner arc surface and side surfaces connecting the outer arc surface and the inner arc surface,
• the outer arc surface includes first to fourth portions surrounding the air-core portion, the first and second portions being longer than the third and fourth portions, the first and second portions extending in a direction of an axis of the cylindrical shape of the annular portion, and
• the first resin covers a part of the first portion or the second portion of the outer arc surface and the first resin extends from the air-core portion to one of the side surfaces.