Stator manufacturing method

1. A method for manufacturing a stator including

a stator core including a plurality of slots,

a plurality of coils each including

a pair of slot-housed portions housed in the slots, and

a coil end portion connected to the pair of slot-housed portions and protruded from an end face of the stator core in a central axis direction of the stator core, and

an insulating sheet,

the method comprising:

an insulating sheet preparing step involving preparing the insulating sheet including a plurality of folded portions extending in the central axis direction;

an insulating sheet placing step involving, after the insulating sheet preparing step, placing the insulating sheet in the slots of the stator core;

a first slot-housed portion placing step involving placing a first slot-housed portion of each pair of the slot-housed portions in a first slot included in the slots; and

a second slot-housed portion placing step involving, simultaneously with or after the first slot-housed portion placing step, moving a second slot-housed portion of each pair of the slot-housed portions radially outward while unfolding the insulating sheet in a radially outward direction, intersecting a direction of extension of the folded portions of the insulating sheet, thus placing each second slot-housed portion in a second slot included in the slots and different from the first slot.

2. The stator manufacturing method according to claim 1 , further comprising a coil forming step involving, after the insulating sheet placing step and before the second slot-housed portion placing step, increasing a distance between each pair of the slot-housed portions while unfolding the insulating sheet in the radially outward direction, intersecting the direction of extension of the folded portions of the insulating sheets so as to move the second slot-housed portion of each pair of the slot-housed portions to a circumferential position corresponding to the second slot included in the slots and different from the first slot, thus forming the coils.

3. The stator manufacturing method according to claim 2 , wherein

the insulating sheet includes

a first coil end portion insulator to be placed on a first side in the central axis direction,

a second coil end portion insulator to be placed on a second side in the central axis direction, and

a pair of connections connecting the first coil end portion insulator with the second coil end portion insulator, and

the second slot-housed portion placing step involves placing one of each pair of the connections between the associated first slot-housed portion and an inner surface of the stator core that defines a bottom of the associated first slot on a first radial side, placing the other one of each pair of the connections between the associated second slot-housed portion and a radial pressing jig that presses the associated second slot-housed portion from a second radial side to the first radial side, and radially moving, in this state, each second slot-housed portion by the radial pressing jig, thus placing each second slot-housed portion.

4. The stator manufacturing method according to claim 3 , wherein the insulating sheet placing step involves placing the insulating sheet in the stator core before the first slot-housed portion placing step.

5. The stator manufacturing method according to claim 4 , wherein the insulating sheet placing step involves placing the insulating sheet in the stator core, with the insulating sheet retained by a first retaining jig placed between the insulating sheet and teeth that define the first slots.

6. The stator manufacturing method according to claim 5 , wherein the insulating sheet placing step involves placing the insulating sheet in the stator core, with the insulating sheet retained by an outer jig and an inner jig, the outer jig being included in the first retaining jig and placed between the insulating sheet and the teeth, the inner jig being included in the first retaining jig and placed inside the associated first slot such that the inner jig is located inward of the insulating sheet, the insulating sheet being interposed between the outer jig and the inner jig.

7. The stator manufacturing method according to claim 2 , wherein the insulating sheet placing step involves placing the insulating sheet in the stator core before the first slot-housed portion placing step.

8. The stator manufacturing method according to claim 2 , wherein

the insulating sheet placing step involves placing the insulating sheet together with the coil, with the insulating sheet attached to the coil, and

the insulating sheet preparing step includes a step of fixing the folded portions to each other such that the folded portions of the insulating sheet will not be spread out.

9. The stator manufacturing method according to claim 2 , wherein

the coil forming step involves, with the insulating sheet placed on a first circumferential side of the coil end portion, pressing each second slot-housed portion from a second circumferential side to the first circumferential side by a circumferential pressing jig so as to move each second slot-housed portion to a circumferential position adjacent to the second slot while unfolding the folded portions, thus forming the coils.

10. The stator manufacturing method according to claim 1 , wherein

the stator further includes a slot insulating sheet placed in the slots such that the slot insulating sheet is located between each pair of the slot-housed portions and teeth that define the slots, and

the method further comprises a step of placing the slot insulating sheet in the slots before the insulating sheet placing step.

11. The stator manufacturing method according to claim 2 , wherein

the stator further includes a slot insulating sheet placed in the slots such that the slot insulating sheet is located between each pair of the slot-housed portions and teeth that define the slots, and

the method further comprises a step of placing the slot insulating sheet in the slots before the insulating sheet placing step.