Method for manufacturing a stator winding
A stator winding is manufactured by a forming step, a winding step, and a expanding step. In the forming step, an S-shaped offset shape is formed on a conductor part corresponding to a coil end part. Thereby, in a coil end part, it is possible to provide an expected shape stably at the coil end part. The conductor is wound around a bobbin in the winding step. In the winding step, a twisted shape is given to the conductor parts to be the inclined part of the coil end and the conductor part to be accommodated in a slot. In the expanding step, a preform product removed from the bobbin is expanded into a shape of the stator winding.
1. A method for manufacturing a stator winding, which has a plurality of slot conductor parts accommodated in a plurality of slots of a stator core and a plurality of coil end parts connecting the slot conductor parts, the slot conductor parts being located in radial locations which are alternately displaced in an inner side and outer side manner along a circumferential direction, the method comprising:
a winding step which forms a helical shape winding assembly by winding a conductor on a bobbin; and
an expanding step which deforms the winding assembly into a shape of the stator winding by deforming in a radial direction of the helical shape, and wherein
the stator winding is a wave winding, and wherein
the coil end part has inclined parts and a top part, and wherein
the conductor has a rectangular shape in cross section, and wherein
the winding step rotates the conductor itself in a twisted shape, and wherein the expanding step rotates the conductor in a reverse, direction to undo the twisted shape.
2. The method for manufacturing a stator winding in claim 1 , wherein the twisted shape appears on the inclined parts and the slot conductor part.
3. The method for manufacturing a stator winding in claim 2 , wherein the shape including the twisted shape on the inclined parts is formed by press forming the conductor in the winding step.
4. The method for manufacturing a stator winding in claim 2 , wherein the twisted shape is given by applying a twisting rotation force on the conductor at an end of the slot conductor part which is connected to a succeeding one of the inclined part after the slot conductor part is wound on the bobbin.