TW201312905A - Stator of cylindrical linear motor, cylindrical linear motorand winding method of stator coil of cylindrical linear motor - Google Patents

Abstract

Provided is a winding method of a cylindrical linear motor capable of increasing a contact area between coil and yoke, enhancing radiation performance, and improving magnetic features with excellent magnetic balance, wherein the cylindrical linear motor comprises stator 10 having long cylindrical yoke 8 made of magnetic material and plural short cylindrical coils 4A of U phase, V phase and W phase arranged in plurality along an axial direction upon an inner diameter side of yoke 8, and movable components 20 disposed upon the inner side of stator 10 while facing each other with magnetic gap in between and movable along the axial direction and interposed with plural permanent magnets 6 along the axial direction. Further, crossover 5A of coils 4A of each phase of stator 10 is arranged upon inner circumferential face of coils 4A. Thereby, crossover process is conducted upon the inner diameter side of coils 4A, and the outer circumferential portion of coils 4A can become a true cylindrical shape. As a result, the radiation performance and magnetic features can be enhanced without the need to form unevenness upon yoke 8 while simplifying the process.

Description

Rolling method of stator of cylindrical linear motor, cylindrical linear motor and stator coil of cylindrical linear motor

The present invention relates to a stator having a cylindrical linear motor in which a plurality of coils are arranged in the axial direction on the inner diameter side of the cylindrical yoke, and is provided to be disposed opposite to the stator, A cylindrical linear motor in which a movable member of a plurality of permanent magnets is axially inserted, and a winding method of a stator coil of a cylindrical linear motor.

Fig. 11 is a side cross-sectional view showing a conventional cylindrical linear motor described in, for example, Patent Document 1. Fig. 12 is a cross-sectional view taken along the line C-C of Fig. 11 in the direction of the arrow. In Fig. 11, 10 is the stator, 20 is the movable part, 3 is the supporting mechanism, 4 is the U-phase, V-phase, W-phase coil, 15 is the U-phase, V-phase, W-phase jumper, 6 is permanent The magnet, 7 is a sheath, and 8 is a yoke.

In the stator 10, a plurality of short cylindrical (annular) coils 4 constituting a U phase, a V phase, and a W phase are arranged in the axial direction inside the yoke 8 formed of a long cylindrical magnetic body. It is fixed to the yoke 8 by an adhesive method. The coils 4 are arranged in plural in the axial direction, and are respectively joined by the jumper wires 15 of the respective phases. The jumper 15 of the coil 4 of each phase is concentrated in one portion in the circumferential direction as shown in Fig. 12, and is formed so as to be in close contact with the surface of the coil 4.

The movable member 20 is formed by inserting a plurality of cylindrical permanent magnets 6 in the axial direction inside the cylindrical sheath 7 extending in the axial direction. The movable member 20 is supported by the support mechanism 3 so as to be movable in the axial direction with a slight gap from the stator 10. With the cylindrical linear motor thus constructed, An axial thrust occurs between the sub-10 and the movable member 20 and is output to the outside.

In the conventional cylindrical linear motor, since the jumper wires of the coil are concentrated at one portion and are in close contact with the surface of the coil, the copper wires constituting the coils of the respective phases are arranged between the jumpers of each other, or the jumper and the coil. Inter-contact. Therefore, the insulation between the phases is composed only of the insulating film of the copper wire, and the mechanical stress applied to the copper wire or the pinhole existing in the copper wire film may cause a problem that the dielectric breakdown voltage is lowered.

On the other hand, in the cylindrical linear motor of Patent Document 1, in order to secure the accommodation space of the jumper, the yoke is provided with a convex portion (a concave portion when viewed from the inner diameter side) to secure a space for the jumper and the wire. Increased workability and ease of production.

Further, according to the cylindrical linear motor of Patent Document 2, the winding type of the toroidal coil is used, and the process of the jumper is performed on the inner and outer sides, so that the continuous winding can be performed. Further, in order to secure the space of the jumper, a notch portion is provided in the yoke of the short cylindrical outer circumference to form a gap to secure the space.

(previous technical literature) (Patent Literature)

(Patent Document 1) Japanese Patent Laid-Open Publication No. 2008-79358

(Patent Document 2) Japanese Patent Laid-Open Publication No. 2006-223090

However, according to the above-described conventional technique, since the wire bonding process and the jumper wire process are performed on the outer circumferential side of the coil, it is necessary to ensure accommodation on the outer circumferential side of the coil. The space for the connection and jumper. Therefore, it is necessary to provide a notch or a convex portion in the yoke or to provide a gap between the coil and the yoke.

When the yoke is provided with a notch or a convex portion, since the core portion of the yoke disappears or the distance becomes long, there is a problem that the magnetic characteristics are lowered. In addition, although it differs depending on the manufacturing precision, if the notch portion is not formed with a good balance, magnetic imbalance occurs, and cogging torque or torque ripple occurs. When the magnetic attraction force is unbalanced and the shaft is deformed, the accuracy of the shaft displacement is deteriorated, which is a problem. Further, since the yoke is provided with a notch or a convex portion, it is necessary to machine the yoke into a special shape by machining or the like. Therefore, the cost is increased as compared with the case where the yoke is a perfect circular shape, which is a problem.

On the other hand, if a gap is provided between the coil and the yoke, the outer peripheral surface of the short cylindrical coil as a heat source and the yoke portion that transmits thermal energy to the outer casing may have heat insulation. The air layer of the air causes the heat dissipation of the coil to deteriorate.

The present invention has been made in view of the above problems, and an object thereof is to provide a stator and a cylindrical type of a cylindrical linear motor in which a contact area between a coil and a yoke is increased, heat dissipation is improved, magnetic balance is improved, magnetic characteristics are improved, and processing is easy. A winding method of a stator coil of a linear motor and a cylindrical linear motor.

In order to solve the above problems and achieve the object, the stator of the cylindrical linear motor of the present invention is characterized in that it has a long cylindrical yoke formed of a magnetic body, and a short cylindrical shape and a yoke. The inner diameter side is arranged in the axial direction with a plurality of U-phase, V-phase, and W-phase coils, and the cross-coils of the respective phases The wiring system is disposed on the inner circumferential surface of the coil.

Further, the cylindrical linear motor of the present invention is characterized in that it has a stator and a movable member, and the stator has a long cylindrical yoke formed of a magnetic body and a short cylindrical shape and magnetic A plurality of U-phase, V-phase, and W-phase coils are arranged in the axial direction on the inner diameter side of the yoke; and the movable member is opposed to the inner side of the stator via a magnetic gap, and is movable in the axial direction. And a plurality of permanent magnets are inserted in the axial direction; and the jumper wires of the coils of the respective phases of the stator are disposed on the inner circumferential surface of the coil.

Further, in the method of winding a stator coil of a cylindrical linear motor according to the present invention, the stator coil has a long cylindrical yoke formed of a magnetic body, and each has a short cylindrical shape and a yoke. The plurality of first, second, and third plurality of coils are arranged in the axial direction of the inner diameter side, and the step of winding the stator coil of the cylindrical linear motor includes: using the first, second, and third First, after the first coil is wound, the jumper is pulled out from the inner diameter end of the first coil in the axial direction, and then the second coil adjacent to the first coil is wound around the first coil. The outer side of the jumper of the coil is pulled out from the inner diameter end of the second coil in the axial direction, and then the third coil adjacent to the second coil is wound around the jumper of the first coil and the second coil. On the outer side, the jumper wire is pulled out from the inner diameter end of the third coil in the axial direction, and then the first coil adjacent to the third coil is wound around the outer side of the jumper of the second coil and the third coil, and the first coil is wound. The inner diameter end pulls the jumper wire axially, and by repeating the above steps, the jumper of the coil of each phase of the stator is disposed on the inner circumference of the coil .

By performing all the wire bonding processing and the jumper wire processing in the short cylindrical inner diameter, the outer circumference of the short cylindrical shape can be formed into a cylindrical shape, and it is not necessary to provide a notch or a convex portion in the yoke. The contact area between the coil and the yoke is increased, and the heat dissipation is improved. Further, since the yoke is cylindrical, magnetic imbalance does not occur and magnetic characteristics are not lowered. Further, since the yoke is cylindrical, processing is also relatively easy.

Hereinafter, embodiments of the winding method of the stator, the cylindrical linear motor, and the stator coil of the cylindrical linear motor according to the present invention will be described in detail with reference to the drawings. However, the invention should not be limited by the embodiment.

<Embodiment 1>

Fig. 1 is a side sectional view showing a cylindrical linear motor according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view taken along the line A-A of Fig. 1 in the direction of the arrow. In Fig. 1, 10 is a stator, 20 is a movable member, 3 is a support mechanism, 4A is a U-phase, V-phase, and W-phase coil, 5A is a U-phase, V-phase, and W-phase jumper, and 6 is permanent. The magnet, 7 is a sheath, and 8 is a yoke.

In the stator 10, a plurality of short cylindrical (annular) coils 4A constituting a U phase, a V phase, and a W phase are arranged in the axial direction inside the yoke 8 formed of a long cylindrical magnetic body. It is fixed to the yoke 8 by an adhesive method. The coil 4A is disposed in plural in the axial direction, and is joined by the jumper wires 5A of the respective phases. As shown in Fig. 2, the jumper wire 5A of the present embodiment is disposed on one side in the circumferential direction on the radial inner diameter side of the coil 4A, and is disposed so as to be in close contact with the inner circumferential surface of the coil 4A.

The movable member 20 is on the inner side of the cylindrical sheath 7 extending in the axial direction, toward A plurality of cylindrical permanent magnets 6 are axially inserted. The movable member 20 is opposed to the stator 10 with a slight magnetic gap (gap), and is supported by the support mechanism 3 so as to be movable in the axial direction. Here, the axial direction refers to the movable direction of the movable member 20. According to the cylindrical linear motor having such a configuration, axial thrust is generated between the stator 10 and the movable member 20 in the same manner as the conventional article, and the thrust is output to the outside by the movement of the movable member 20.

Fig. 3 is a view showing an arrangement position of the jumper 5A of the coil 4A of the cylindrical linear motor of the first embodiment, and is an enlarged view of a portion B of Fig. 1. Fig. 4 is a flow chart showing the winding procedure of the coil 4A of the cylindrical linear motor of the first embodiment. Here, in the drawings 3 and 4, only the coil 4A and its jumper 5A are shown, and the movable member 20 or the winding tool is not described. Fig. 5 is a partially enlarged sectional view showing a coil 4A of a cylindrical linear motor according to the first embodiment.

In Fig. 3, the bridging process of the respective phases of the U phase, the V phase, and the W phase is disposed on the inner diameter side (inner peripheral surface), and the connection between the coils 4A can be performed. Further, by performing the jumper processing and the wire bonding process on the inner diameter side of the coil 4A, the outer diameter side of the coil 4A can be designed in a cylindrical shape without irregularities to increase the contact area with the yoke 8. Further, since the outer circumferential surface of the coil 4A is a perfect circular cylindrical shape having no concavities and convexities, the coil 4A can be inserted into the yoke 8 by a light press fit or a shrinkage fit. Thereby, the thermal conductivity is improved, and the fixing reliability of the coil 4A is improved.

The winding method of the coil 4A and the wiring method of the jumper 5A according to the present embodiment will be described with reference to Fig. 4 . Among them, in Figure 4, shown in Figure 3 In the coil 4A, the coil of the U phase (first phase) is 4u, the coil of the V phase (second phase) is 4v, and the coil of the W phase (third phase) is 4w. Further, in the jumper 5A shown in Fig. 3, the U-phase (first phase) jumper is set to 5u, and the V-phase (first phase) jumper is set to 5v, and the W phase ( The jumper of the third phase is set to 5w.

The U-phase, V-phase, and W-phase coils 4u, 4v, and 4w are formed by being wound around a cylindrical rod-shaped winding tool (not shown), and then taken out from the winding tool and inserted into the yoke 8 (No. 2)). Fig. 4 is a view schematically showing a state of being wound around a winding tool. The package of the coil 4A is carried out using three pull wires 9u, 9v, and 9w of one phase of each of the U phase, the V phase, and the W phase. First, the U-phase coil 4u is wound. After the U-phase coil 4u is wound, the jumper wire 5u is pulled out in the axial direction from the inner diameter side end of the U-phase coil 4u. The jumper 5u is wound in the axial direction by a coil width of two phases (Fig. 4(a)).

Next, the V-phase coil 4v adjacent to the U-phase coil 4u is wound around the jumper 5u of the U-phase coil 4u (outside). When the winding of the V-phase coil 4v is completed, the jumper wire 5v is pulled out from the inner diameter side end of the V-phase coil 4v, and the coil width of the two phases is wound in the axial direction in the same manner as the U-phase coil 4u. 4 Figure (b)).

Next, the W-phase coil 4w adjacent to the V-phase coil 4v is wound around the jumper 5u and the jumper 5v (outer side) (Fig. 5(c)). Thereafter, the U-phase, V-phase, and W-phase coils 4u, 4v, and 4w are wound around the jumper wires (outer sides) of the other two (two-phase) coils, respectively.

According to the above aspect, the winding method of the stator coil of the cylindrical linear motor according to the present embodiment uses three pull wires 9u, 9v, and 9w, respectively. The two-phase bridging process of winding and extending in the axial direction is performed in the respective order of the phases, and the winding of the first coil is wound around the second and third windings (outside) by repeating this The continuous jumper processing can be performed by the operation, and the workability is improved because the wire bonding operation is not required. In addition, by performing the jumper processing on the inner circumferential surfaces of the coils 4u, 4v, and 4w, it can be easily wound on the other two-phase jumper (outer side) without having to avoid the other two-phase jumper wires. Winding, so continuous winding can be easily performed even without special design for the winding pattern or winding machine.

The fixing of the jumper wires 5u, 5v, and 5w is fixed to the inner circumferential surfaces of the respective coils 4u, 4v, and 4w using varnish. Thereby, the shape stability is imparted to each of the coils 4u, 4v, and 4w, and the jumper wires 5u, 5v, and 5w are not detached from the inner diameter side, and the jumper wires 5u, 5v, and 5w are fixed to impart a shape. Stability, that is, there is no possibility of falling off on the inner diameter side, and insulation can be added to the jumper wires 5u, 5v, 5w.

By using the winding method as described above, the jump wires 5u, 5v, and 5w of the respective coils can be disposed on the inner diameter side by forming the respective coils 4u, 4v, and 4w arranged in the axial direction. Further, the electric wires constituting the respective coils 4u, 4v, and 4w of the U phase, the V phase, and the W phase are continuous structures (continuous winding) having no joint. By continuous winding in the above manner, since the knots between the coils are not required, there is no possibility that the productivity is deteriorated. In addition, by arranging the jumper wires 5u, 5v, and 5w on the inner circumferential surface of the coil, the winding can be performed on the other two-phase jumper wires, and after the predetermined coil winding is completed, the next winding can be directly performed. line.

Furthermore, the coil 4A of the present embodiment is wound by a winding tool. Forming, but it can also be formed by winding a bobbin (reel frame) which is not shown in the winding tool, and then taken out by the winding tool together with the bobbin, and inserted in the yoke 8 (Figure 2). At this time, the jumper wire 5A is hung in a groove recessed in the coil winding surface of the bobbin (reel frame) not shown.

As described above, the cylindrical linear motor according to the embodiment includes the stator and the movable member. The stator has a long cylindrical yoke 8 formed of a magnetic material, and a U-phase, a V-phase, and a W-phase, which are each formed in a short cylindrical shape and arranged in the axial direction on the inner diameter side of the yoke 8. The plurality of coils 4A of the phase; the movable member 20 is disposed on the inner side of the stator 10 with a magnetic gap therebetween, and is disposed to be movable in the axial direction, and a plurality of permanent magnets 6 are inserted in the axial direction. The jumper 5A of the coil 4A of each phase of the stator 10 is disposed on the inner circumferential surface of the coil 4A. By performing all the wire bonding processing and the jumper processing on the inner diameter side of the coil 4A, the outer peripheral portion of the coil 4A can be formed in a cylindrical shape, and it is not necessary to provide a notch or a convex portion in the yoke 8, so the coil 4A and the magnetic body The contact area of the yoke 8 is increased, and heat dissipation is improved. Further, since the yoke 8 has a cylindrical shape, magnetic imbalance does not occur and magnetic characteristics are not lowered. Further, since the yoke 8 is cylindrical, processing is also easy.

Further, the jumper wire 5A of the present embodiment is fixed to the inner circumferential surface of each of the coils 4A by varnish, but may be fixed by an adhesive, an adhesive tape, a resin or the like, and is not limited to the varnish.

<Embodiment 2>

Fig. 6 is a partially enlarged view showing the appearance of a coil of the cylindrical linear motor of the second embodiment. Figure 7 is a cylindrical linear motor of Embodiment 2. Cross section view. The coil 4B of the present embodiment is formed by a so-called flatwise winding in which a wide flat surface of a flat electric wire having a flat cross section is overlapped with each other and wound by a plurality of slits without a gap. As shown in Fig. 6, the coil 4B of the present embodiment, which is a flat-shaped flat wire having a flat cross-section, can be wound without a gap as compared with the coil 4A of the first embodiment (fifth drawing) in which a circular electric wire is used. Winding, and the duty factor is higher. As shown in Fig. 7, the jumper wire 5B has a flat cross section, and is, in other words, curved in the width direction along the inner circumferential surface of the coil 4B. Among them, the coil 4B of Fig. 7 is exaggerated to describe its characteristics, and is easy to understand.

According to the coil 4B of the present embodiment, by using a flat electric wire, the space of the jumper wire 5B can be reduced, and the duty factor can be increased, so that the loss can be reduced and the size can be reduced. Further, by forming a flat wire by using a flat electric wire, the outer shape of the coil 4A can be completely formed into a perfect circular shape, and the contact area with respect to the yoke 8 can be further increased, so that heat conduction can be improved.

In the coil 4A (Fig. 5) of the first embodiment, even when a wire having a circular cross section is used, only the portion of the jumper wire is flattened to have a flat cross section, and the jumper can be saved. Spatial or miniaturized.

<Embodiment 3>

Fig. 8 is a cross-sectional view showing a cylindrical linear motor of the third embodiment. In the present embodiment, a metal tube (SUS tube) for holding a magnet is used as the sheath 7 covering the outer peripheral portion of the movable member 20. A groove 20a is formed along the axial direction on the outer circumferential surface of the sheath 7, and the jumper wire 5A is disposed in the groove 20a. The other configuration is the same as that of the first embodiment.

With this design, the jumper space is not wasted, and the magnetic gap can be shortened (activity A slight magnetic gap between the member 20 and the stator 10). In particular, when the SUS tube for magnet holding is used as the sheath 7 on the movable member side, the jumper space can be provided without affecting the magnetic characteristics.

Further, the movable member 20 of the present embodiment has a sheath 7 covering the outer peripheral portion, and the groove 7a for the jumper 5A is formed in the sheath 7, but even a movable member having no sheath can be borrowed A groove having a wrap line is formed on the outer peripheral surface to obtain substantially the same effect.

<Embodiment 4>

Fig. 9 is a cross-sectional view showing a cylindrical linear motor of the fourth embodiment. In the present embodiment, three grooves 20b are formed in the outer circumferential surface of the movable member 20 so as to extend the axial direction at a pitch of 120 degrees in order to achieve the purpose of avoiding the jumper wire 5D. A jumper wire 5D of each of the U-phase, V-phase, and W-phase coils 4A is disposed at the position of the three grooves 20b. The other configuration is the same as that of the third embodiment. According to the cylindrical linear motor of the present embodiment, an unbalance of magnetic attraction force is not generated, and a stable thrust can be output.

<Embodiment 5>

Fig. 10 is a partially enlarged view showing a state of coil winding of the cylindrical linear motor of the fifth embodiment. In the U-phase, V-phase, and W-phase coils 4C of the present embodiment, only one of the three pull wires 9 provided in each phase is wound and formed into one layer parallel to the shaft. In the present embodiment, the coil 4C is wound in the radial direction so that the number of segments is only one step (one layer), and the other configuration is such that the coil 4C is wound in a plurality of stages in the first embodiment. The same as the first embodiment. According to the cylindrical linear motor of the present embodiment, the outer peripheral shape of the coil can be easily formed into a cylindrical shape having a substantially circular cross section, and the yoke 8 can be added. The contact area increases the thermal conductivity.

(industrial availability)

As described above, the cylindrical linear motor of the present invention is most suitable for a cylindrical linear motor having a plurality of plural coils arranged in the axial direction on the inner diameter side of the cylindrical yoke.

3‧‧‧Support institutions

4, 4A, 4B, 4C, 4u, 4v, 4w‧‧‧ coil

15, 5A, 5B, 5D, 5u, 5v, 5w‧‧‧ jumper

6‧‧‧ permanent magnet

7‧‧‧ sheath

8‧‧‧Y yoke

9, 9u, 9v, 9w‧‧‧ winding machine cable

10‧‧‧ Stator

20‧‧‧Activities

20a, 20b‧‧‧ trench

Fig. 1 is a side sectional view showing a cylindrical linear motor according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along the line A-A of Fig. 1 in the direction of the arrow.

Fig. 3 is a view showing a jumper arrangement position of a coil of a cylindrical linear motor according to the first embodiment, which is an enlarged view of a portion B of Fig. 1.

Fig. 4 (a) to (c) are process diagrams showing the winding sequence of the coil of the cylindrical linear motor of the first embodiment.

Fig. 5 is a partially enlarged cross-sectional view showing the coil of the cylindrical linear motor of the first embodiment.

Fig. 6 is a partially enlarged view showing the appearance of a coil of the cylindrical linear motor of the second embodiment.

Fig. 7 is a cross-sectional view showing a cylindrical linear motor of the second embodiment.

Fig. 8 is a cross-sectional view showing a cylindrical linear motor of the third embodiment.

Fig. 9 is a cross-sectional view showing a cylindrical linear motor of the fourth embodiment.

Fig. 10 is a partially enlarged view showing a coil package state of the cylindrical linear motor of the fifth embodiment.

Figure 11 is a side cross-sectional view of a conventional cylindrical linear motor.

Fig. 12 is a cross-sectional view taken along the line C-C of Fig. 11 in the direction of the arrow.

4A‧‧‧ coil

5A‧‧‧ Jumper

8‧‧‧Y yoke

10‧‧‧ Stator

20‧‧‧Activities

Claims (12)

A stator of a cylindrical linear motor having a long cylindrical yoke formed of a magnetic body; and each having a short cylindrical shape and arranged in the axial direction on the inner diameter side of the yoke The plurality of coils of the U phase, the V phase, and the W phase, and the jumper of the coils of the respective phases are disposed on the inner circumferential surface of the coil. A cylindrical linear motor comprising: a stator having a long cylindrical yoke formed of a magnetic body; and each having a short cylindrical shape and arranged in the axial direction on an inner diameter side of the yoke a plurality of U-phase, V-phase, and W-phase coils; and a movable member disposed on the inner side of the stator with a magnetic gap interposed therebetween and movable in the axial direction, and inserted in the axial direction a plurality of permanent magnets; and a jumper of the coils of the respective phases of the stator is disposed on an inner circumferential surface of the coil. The cylindrical linear motor according to claim 2, wherein the coil is formed by winding a flat electric wire. A cylindrical linear motor according to claim 2, wherein the plurality of coils in the same phase and the jumper bridges across the coils are continuously wound without a wire joint. The cylindrical linear motor of claim 2, wherein the jumper wire has a flat cross-sectional shape. Cylindrical linear horse as described in item 2 or 3 of the patent application In the above, the jumper wire is fixed to the inner circumferential surface of the coil by any one of a varnish, an adhesive, an adhesive tape, and a resin. The cylindrical linear motor according to claim 2, wherein the outer peripheral surface of the movable member is formed with a groove along an axial direction, and the jumper is formed in the groove. Within the space. The cylindrical linear motor according to claim 3, wherein the coil is wound in a flat manner by the flat electric wire. The cylindrical linear motor according to any one of claims 2 to 3, wherein the coil is formed by winding only one layer parallel to the shaft. The cylindrical linear motor according to any one of claims 2 to 3, wherein the coil is press-fitted into the yoke. The cylindrical linear motor according to any one of claims 2 to 3, wherein the stator is provided with a bobbin in which the coil is wound, and the jumper is attached to the recess It is disposed in the groove of the aforementioned bobbin. A winding method of a stator coil of a cylindrical linear motor, the stator coil having a long cylindrical yoke formed of a magnetic body, and a short cylindrical shape and an inner diameter of the yoke The plurality of first, second, and third plurality of coils are arranged side by side in the axial direction, and the step of winding the stator coil of the cylindrical linear motor includes: using the first, second, third, and third First, after winding the first coil, the jumper wire is pulled out from the inner diameter end of the first coil toward the axial direction. Next, the second coil adjacent to the first coil is wound around the jumper of the first coil, and the jumper is pulled out from the inner diameter end of the second coil in the axial direction, and then a third coil adjacent to the coil is wound around the jumper of the first coil and the second coil, and the jumper is pulled out from the inner diameter end of the third coil in the axial direction, and then the third coil is connected The adjacent first coil is wound around the outer side of the jumper of the second coil and the third coil, and the jumper is pulled out from the inner diameter end of the first coil in the axial direction, and the stator is reversed by the above steps. The jumper of the coil of each of the above phases is disposed on the inner circumferential surface of the coil.