Patent ID: 8631564

Claim:
A stator core in combination with a spool for a coil winding device for forming coils, wherein the coils are to be loaded in slots between teeth of the stator core by using a coil insertion device, the spool comprising: a front spool part that is formed to have a plurality of coil winding surfaces formed to increase in diameter stepwise from the bottom upwards in a state where the spool is set on the coil winding device, and a rear spool part that is formed to have a plurality of coil winding surfaces formed to increase in diameter stepwise from the bottom upwards in the state where the spool is set on the coil winding device, wherein the front spool part and the rear spool part are placed at a distance from each other so that each turn of coil has a length corresponding to arbitrary lamination thickness of the stator core, and wherein the plurality of coil winding surfaces of the front spool part includes a coil winding surface corresponding to an outermost coil, the coil winding surface being dimensioned so that when the outermost coil is wound on the coil winding surface, the outermost coil includes first and second straight-line portions angled relative to each other; and if the first and second straight-line portions of the outermost coil are arranged parallel to respective first and second radial lines extending from a central axis of the stator core and if the first and second straight-line portions of the outermost coil overlap the respective first and second radial lines extending from the central axis of the stator core when viewing the first and second straight-line portions of the outermost coil along an axial direction of the stator core, the first straight-line portion of the outermost coil extends from a first position spaced apart from the central axis of the stator core to a second position radially outwardly of a core back where the roots of the teeth outside the slots of the stator core are connected when viewing the first straight-line portion of the outermost coil along the axial direction of the stator core.