Linear material and stator structure
A stator structure includes: a stator core ( 104 ) having a large number of concave slots ( 105 ) and a large number of convex magnetic poles ( 106 ) circumferentially alternately arranged; and magnet wires ( 101 ) of rectangular cross section in each of which an insulating coating ( 103 ) is formed on the outer surface of a metal wire ( 102 ), wherein each of the slots ( 105 ) is formed so that the distance (W 2 ) between both the side surfaces ( 109, 109 ) of the slot ( 105 ) gradually decreases from the bottom ( 107 ) to a distal opening ( 108 ) of the slot ( 105 ), each of the magnet wires ( 101 ) is wound around the associated magnetic pole ( 106 ) and inserted in tiers in the associated slot ( 105 ), and the magnet wire ( 101 ) is placed in the slot ( 105 ) so that the width (W 1 ) thereof continuously or stepwise decreases from the bottom ( 107 ) to the distal opening ( 108 ) of the slot ( 105 ).
1. A method of fabricating a linear material, the method comprising the steps of:
forming a metal wire so that the metal wire has a rectangular shape, and one of periodically and continuously changing a width and a thickness of the metal wire along a longitudinal direction thereof so that the transverse cross-sectional area of the metal wire is constant along the longitudinal direction thereof, and
forming an insulating coating by electrodepositing on the outer surface of the metal wire.
2. The method of claim 1 , wherein the linear material is formed by concurrently pressing the metal wire horizontally and vertically by using a fylfot-arranged roll assembly having an upper roll and a lower roll and a pair of lateral rolls.
3. The method of claim 1 , wherein the linear material is formed by pressing the metal wire by using a pair of pressure rolls arranged so that the rotational axes of the pressure rolls are transverse with respect to each other.
4. The method of claim 1 , wherein the linear material is formed by passing through a rectangular space between one of a pressure roll having a groove that changes width and depth in a circumferential direction with respect to the roll, and an opposing pressure roll having no groove.
5. The method of claim 1 , wherein the linear material is formed by pressing the metal wire into a die having a groove that changes width and depth of along a longitudinal direction of the die.
6. The method of claim 1 , further comprising a step of attaching marks to the metal wire at predetermined pitches.