Method of manufacturing stator

1 . A method of manufacturing a stator in which numerous rectangular wire coils, which are shaped in U-shapes having both leg portions respectively inserted into respective slots of a stator core from one side in an axial direction of the stator core, are superposed in a plurality of layers in a radial direction of the stator core and are arrayed in annular forms, the method comprising:

setting lengths in the axial direction of the both leg portions of the rectangular wire coils such that the lengths become longer in a stepwise manner from a layer at an inner side toward a layer at an outer side of the plurality of layers;

of the both leg portions of each of the rectangular wire coils, forming a leg portion at one side in a peripheral direction of the stator core to be longer in the axial direction than a leg portion at another side in the peripheral direction;

within each of the slots, at each of the respective layers, superposing the leg portion at the one side of one of the rectangular wire coils on an outer side in the radial direction of the leg portion at the other side of another of the rectangular wire coils;

placing a first jig, which has a stepped portion shaped in a form of steps heading downward toward an outer side in the radial direction, at another side in the axial direction with respect to the numerous rectangular wire coils, and making respective steps of the stepped portion face the layers, respectively;

causing a second jig to abut the numerous rectangular wire coils from the one side in the axial direction, and pushing the second jig toward the other side in the axial direction; and

of the leg portions at the one sides and the leg portions at the other sides of the respective layers, causing only distal ends of the leg portions at the one sides to abut the steps, respectively.

2 . The method of manufacturing a stator of claim 1 , wherein the numerous rectangular wire coils are moved toward the other side in the axial direction relative to the stator core, in a state in which the first jig and the second jig are made to abut the numerous rectangular wire coils.

3 . The method of manufacturing a stator of claim 1 , wherein, after the first jig and the second jig are made to abut the numerous rectangular wire coils, the numerous rectangular wire coils are moved toward the other side in the axial direction relative to the stator core in a state in which the first jig has been moved apart from the numerous rectangular wire coils.

4 . The method of manufacturing a stator of claim 2 , wherein the stepped portion of the first jig is formed so as to be able to be inserted into the respective slots from the other side in the axial direction, and the numerous rectangular wire coils are made to abut the respective steps of the stepped portion that is inserted in the respective slots.

5 . A method of manufacturing a stator in which numerous rectangular wire coils, which are shaped in U-shapes having both leg portions respectively inserted into respective slots of a stator core from one side in an axial direction of the stator core, are superposed in a plurality of layers in a radial direction of the stator core and are arrayed in annular forms, the method comprising:

setting lengths in the axial direction of the rectangular wire coils such that the lengths become longer in a stepwise manner from a layer at an inner side toward a layer at an outer side of the plurality of layers;

of the both leg portions of each of the rectangular wire coils, forming a leg portion at one side in a peripheral direction of the stator core to be longer in the axial direction than a leg portion at another side in the peripheral direction;

within each of the slots, at each of the respective layers, superposing the leg portion at the one side of one of the rectangular wire coils on an outer side in the radial direction of the leg portion at the other side of another of the rectangular wire coils;

placing a first jig, which has a stepped portion shaped in a form of steps heading downward toward an outer side in the radial direction, at another side in the axial direction with respect to the numerous rectangular wire coils, and making respective steps of the stepped portion face the leg portions of the respective layers, respectively;

causing a second jig to abut the numerous rectangular wire coils from the one side in the axial direction, and pushing the second jig toward the other side in the axial direction; and

causing distal ends of the leg portions of the respective layers to abut the steps, respectively.

6 . The method of manufacturing a stator of claim 5 , wherein:

the stepped portion of the first jig is formed such that steps whose heights in the axial direction are tall and steps whose heights in the axial direction are short are lined-up alternately, and the leg portions at the one sides are made to abut the steps whose heights in the axial direction are tall, and the leg portions at the other sides are made to abut the steps whose heights in the axial direction are short.

7 . The method of manufacturing a stator of claim 1 , wherein the second jig has a plurality of urging portions that urge the numerous rectangular wire coils toward the other side in the axial direction per layer.

8 . The method of manufacturing a stator of claim 1 , wherein, after the numerous rectangular wire coils are pushed by the second jig toward the other side in the axial direction and are moved toward the other side in the axial direction relative to the stator core, the numerous rectangular wire coils are made to abut the first jig in a state in which the second jig has been moved apart from the numerous rectangular wire coils.

9 . The method of manufacturing a stator of claim 3 , wherein the stepped portion of the first jig is formed so as to be able to be inserted into the respective slots from the other side in the axial direction, and the numerous rectangular wire coils are made to abut the respective steps of the stepped portion that is inserted in the respective slots.

10 . The method of manufacturing a stator of claim 5 , wherein the second jig has a plurality of urging portions that urge the numerous rectangular wire coils toward the other side in the axial direction per layer.

11 . The method of manufacturing a stator of claim 5 , wherein, after the numerous rectangular wire coils are pushed by the second jig toward the other side in the axial direction and are moved toward the other side in the axial direction relative to the stator core, the numerous rectangular wire coils are made to abut the first jig in a state in which the second jig has been moved apart from the numerous rectangular wire coils.