Stator and rotary electric machine

Abstract

This stator comprises: two first coils having first insertion portions that are inserted into slots and first bridge portions that run, at coil ends, along a virtual cylinder including the entire outer circumferential surface of a stator core; two second coils having second insertion portions that have spacing narrower than that of the first insertion portions, and second bridge portions that run along the virtual cylinder at coil ends and have a height lower than the first bridge portions in a direction perpendicular to the rotation axis; two third coils having third insertion portions that are inserted into slots, and third bridge portions that run, at coil ends, along an end surface of the stator core perpendicular to the rotation axis; and two fourth coils having two fourth insertion portions that have spacing narrower than that of the third insertion portions, and fourth bridge portions that run along the end surface at coil ends and have spacing narrower than that of the third bridge portions. The eight coils are divided into sets of two coils or sets of four coils connected in series, and the sets are connected in parallel with each other.

Description

Stator and Rotating Electric Machine

[0001] The present invention relates to a stator and a rotating electric machine.

[0002] Currently, rotating electric machines such as motors and generators are used in various fields. Examples of stators for rotating electric machines include the stator disclosed in Patent Document 1 and the stator disclosed in Patent Document 2. The stator disclosed in Patent Document 1 is manufactured by inserting a plurality of U-shaped rectangular wires into slots of a stator core and welding ends of different rectangular wires to each other. The stator disclosed in Patent Document 2 includes a first partial winding having bent portions at both ends in a rotation axis direction, and a second partial winding not having the bent portions.

[0003] Japanese Patent No. 7444733 Japanese Unexamined Patent Application Publication No. 2023-157342

[0004] However, in the above-described coils and windings, variations in machining accuracy, assembly accuracy and the like of components such as the rotor and the shaft may cause each component to be arranged offset with respect to the rotation axis. In such a case, a potential difference occurs between coils connected in parallel, causing a circulating current that flows between these coils. The circulating current does not contribute to torque regardless of whether the rotating electric machine is a motor or a generator, thereby causing a loss.

[0005] Therefore, an object of the present invention is to provide a stator and a rotating electric machine that can suppress circulating current.

[0006] To solve the above-mentioned problems, the stator of the present invention comprises two first coils having two first insertion portions inserted into a slot and two first bridge portions at the coil end that are along a virtual cylinder including the entire outer surface of the stator core; two second coils having two second insertion portions inserted into a slot and spaced closer together than the spacing between the two first insertion portions and two second bridge portions at the coil end that are along the virtual cylinder and have a height lower than the first bridge portions in a direction perpendicular to the rotation axis of the rotating electric machine; two third coils having two third insertion portions inserted into a slot and two third bridge portions at the coil end that are along the end face of the stator core perpendicular to the rotation axis; two fourth coils having two fourth insertion portions inserted into a slot and spaced closer together than the spacing between the two third insertion portions and two fourth bridge portions at the coil end that are along the end face and have a spacing narrower than the spacing between the two third bridge portions. The two first coils, two second coils, two third coils, and two fourth coils are connected in series to form sets of two coils or sets of four coils, and these sets of two coils or these sets of four coils are connected in parallel to each other.

[0007] In the stator of the present invention, a set of four coils, consisting of two first coils and two fourth coils, and a set of four coils, consisting of two second coils and two third coils, are connected in parallel.

[0008] In the stator of the present invention, two sets, each containing one of the first coil, the second coil, the third coil, and the fourth coil, are connected in parallel.

[0009] In the stator of the present invention, at least one of the first coil, the second coil, the third coil, and the fourth coil has a jumper wire at the end of the conductor.

[0010] In the stator of the present invention, at least one of the first coil, the second coil, the third coil, and the fourth coil has the end of the welded wire bent in a direction perpendicular to the rotation axis.

[0011] The rotating electric machine of the present invention comprises one of the stators described above.

[0012] According to the present invention, circulating current can be suppressed.

[0013] This is a diagram showing an example of a stator according to the first embodiment. This is a diagram showing an example of a first coil according to the first embodiment. This is a diagram showing an example of a second coil according to the first embodiment. This is a diagram showing an example of a third coil according to the first embodiment. This is a diagram showing an example of a fourth coil according to the first embodiment. This is a diagram showing an example of a coil set and coil arrangement according to the first embodiment. This is a diagram showing an example of a coil set and coil arrangement according to the first embodiment. This is a diagram showing an example of a jumper wire according to the second embodiment. This is a diagram showing an example of a jumper wire according to the second embodiment. This is a diagram showing an example of a stator coil end according to the second embodiment. This is a diagram showing an example of a stator according to the third embodiment. This is a diagram showing an example of a stator according to the third embodiment. This is a diagram showing an example of a first coil and a second coil according to the third embodiment. This is a diagram showing an example of a third coil and a fourth coil according to the third embodiment. This is a diagram showing an example of a fifth coil and a sixth coil according to the third embodiment.

[0014] The embodiments for carrying out the present invention will be described below with reference to the drawings. In the following description, a motor will be given as an example of a rotating electric machine.

[0015] (First Embodiment) Figure 1 is a diagram showing an example of a stator according to the first embodiment. As shown in Figure 1, the stator 1 comprises a first coil 11, a second coil 12, a third coil 13, a fourth coil 14, and a stator core 19. The stator 1 is cylindrical with the rotation axis A of the rotor as its central axis, and the rotor is inserted inside. The first coil 11, the second coil 12, the third coil 13, and the fourth coil 14 are electrically connected by busbars, jumper wires, etc., thereby forming the coils of the motor including the stator 1. The first coil 11, the second coil 12, the third coil 13, and the fourth coil 14 are formed from conductors such as flat rectangular wires. The stator core 19 is manufactured by stacking plate-shaped members made of electromagnetic steel in the direction of the rotation axis A.

[0016] Figure 2 shows an example of a first coil according to the first embodiment. As shown in Figure 2, the first coil 11 includes a first insertion portion 111, a first insertion portion 112, a first bridge portion 113, and a first bridge portion 114.

[0017] The first insertion portion 111 and the first insertion portion 112 are the parts of the first coil 11 that are inserted into the slots of the stator core 19. The first bridge portion 113 is the part of the first coil 11 that connects one end of the first insertion portion 111 and one end of the first insertion portion 112. When the first insertion portion 111 and the first insertion portion 112 are inserted into the slots, the first bridge portion 113 has a surface 113P at the coil end that follows a virtual cylinder that includes the entire outer surface of the stator core 19. Here, the virtual cylinder is a cylinder that extends the outer surface of the stator core 19 on both sides in the direction of the rotation axis A. The surface 113P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The first bridge portion 114 is the part of the first coil 11 that connects the other end of the first insertion portion 111 and the other end of the first insertion portion 112. The first bridge portion 114 has a surface 114P that, when the first insertion portion 111 and the first insertion portion 112 are inserted into the slot, is aligned with a virtual cylinder at the coil end that includes the entire outer surface of the stator core 19. The surface 114P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder.

[0018] The coil ends described above are regions located on both sides in the direction of the rotation axis A of the stator core 19. The coil ends include the first bridge section 113, the first bridge section 114, the second bridge section 123, the second bridge section 124, the third bridge section 133, the third bridge section 134, the fourth bridge section 143, the fourth bridge section 144, etc. The virtual cylinder described above is the side surface of a right circular column with the rotation axis A as its central axis and a diameter equal to the outer surface of the stator core 19.

[0019] Figure 3 shows an example of a second coil according to the first embodiment. As shown in Figure 3, the second coil 12 includes a second insertion portion 121, a second insertion portion 122, a second bridge portion 123, and a second bridge portion 124.

[0020] The second insertion portion 121 and the second insertion portion 122 are the parts of the second coil 12 that are inserted into the slots of the stator core 19. The distance between the second insertion portion 121 and the second insertion portion 122 is narrower than the distance between the first insertion portion 111 and the first insertion portion 112 of the first coil 11. Furthermore, the second insertion portion 121 and the second insertion portion 122 are inserted into slots located between the slot in which the first insertion portion 111 of the first coil 11 is inserted and the slot in which the first insertion portion 112 is inserted. Specifically, the second insertion portion 121 is inserted into a slot sandwiched between the slot in which the first insertion portion 111 is inserted and the slot in which the fourth insertion portion 142 (described later) is inserted. Similarly, the second insertion portion 122 is inserted into a slot sandwiched between the slot in which the first insertion portion 121 is inserted and the slot in which the fourth insertion portion 141 is inserted.

[0021] The second bridge portion 123 is the part of the second coil 12 that connects one end of the second insertion portion 121 and one end of the second insertion portion 122. When the second insertion portions 121 and 122 are inserted into the slot, the second bridge portion 123 has a surface 123P at the coil end that follows a virtual cylinder including the entire outer surface of the stator core 19. The surface 123P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. Furthermore, the height of the second bridge portion 123 in the direction perpendicular to the rotation axis A is lower than that of the first bridge portion 113 of the first coil 11. Specifically, the height of the surface 123P of the second bridge portion 123 in the direction perpendicular to the rotation axis A is lower than that of the surface 113P of the first bridge portion 113.

[0022] The second bridge portion 124 is the part of the second coil 12 that connects the other end of the second insertion portion 121 to the other end of the second insertion portion 122. When the second insertion portions 121 and 122 are inserted into the slot, the second bridge portion 124 has a surface 124P at the coil end that follows a virtual cylinder including the entire outer surface of the stator core 19. The surface 124P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. Furthermore, the height of the second bridge portion 124 in the direction perpendicular to the rotation axis A is lower than that of the first bridge portion 114 of the first coil 11. Specifically, the height of the surface 124P of the second bridge portion 124 in the direction perpendicular to the rotation axis A is lower than that of the surface 114P of the first bridge portion 114.

[0023] Figure 4 shows an example of a third coil according to the first embodiment. As shown in Figure 4, the third coil 13 comprises a third insertion portion 131, a third insertion portion 132, a third bridge portion 133, and a third bridge portion 134.

[0024] The third insertion portion 131 and the third insertion portion 132 are the parts of the third coil 13 that are inserted into the slots of the stator core 19. The third bridge portion 133 is the part of the third coil 13 that connects one end of the third insertion portion 131 and one end of the third insertion portion 132. When the third insertion portion 131 and the third insertion portion 132 are inserted into the slots, the third bridge portion 133 has a surface 133P that aligns with the end face perpendicular to the rotation axis A of the stator core 19 at the coil end. The surface 133P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The third bridge portion 134 is the part of the third coil 13 that connects the other end of the third insertion portion 131 and the other end of the third insertion portion 132. The third bridge portion 134 has a surface 134P that, when the third insertion portion 131 and the third insertion portion 132 are inserted into the slot, lies along the end face perpendicular to the rotation axis A of the stator core 19 at the coil end. The surface 134P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder.

[0025] Figure 5 shows an example of a fourth coil according to the first embodiment. As shown in Figure 5, the fourth coil 14 comprises a fourth insertion portion 141, a fourth insertion portion 142, a fourth bridge portion 143, and a fourth bridge portion 144.

[0026] The fourth insertion portion 141 and the fourth insertion portion 142 are the parts of the fourth coil 14 that are inserted into the slots of the stator core 19. The distance between the fourth insertion portion 141 and the fourth insertion portion 142 is narrower than the distance between the third insertion portion 131 and the third insertion portion 132 of the third coil 13. Furthermore, the fourth insertion portion 141 and the fourth insertion portion 142 are inserted into slots located between the slot in which the third insertion portion 131 and the slot in which the third insertion portion 132 of the third coil 13 are inserted. Specifically, the fourth insertion portion 141 is inserted into the slot sandwiched between the slot in which the third insertion portion 131 is inserted and the slot in which the second insertion portion 122 is inserted. Similarly, the fourth insertion portion 142 is inserted into the slot sandwiched between the slot in which the third insertion portion 132 is inserted and the slot in which the second insertion portion 121 is inserted.

[0027] The fourth bridge portion 143 is the part of the fourth coil 14 that connects one end of the fourth insertion portion 141 to one end of the fourth insertion portion 142. When the fourth insertion portion 141 and the fourth insertion portion 142 are inserted into the slot, the fourth bridge portion 143 has a surface 143P that aligns with the end face perpendicular to the rotation axis A of the stator core 19 at the coil end. The surface 143P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The fourth bridge portion 144 is the part of the fourth coil 14 that connects the other end of the fourth insertion portion 141 to the other end of the fourth insertion portion 142. When the fourth insertion portion 141 and the fourth insertion portion 142 are inserted into the slot, the fourth bridge portion 144 has a surface 144P that aligns with the end face perpendicular to the rotation axis A of the stator core 19 at the coil end. The surface 144P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The distance between the fourth bridge portion 143 and the fourth bridge portion 144 is narrower than the distance between the third bridge portion 133 and the third bridge portion 134.

[0028] As shown in Figure 1, the second coil 12 is positioned on the side of the rotation axis A in a direction perpendicular to the rotation axis A than the first coil 11. The second insertion portion 121 is inserted into the slot one position inward from the slot in which the first insertion portion 111 is inserted. The second insertion portion 122 is inserted into the slot one position inward from the slot in which the first insertion portion 112 is inserted. The third coil 13 is positioned to surround the fourth coil 14. The fourth coil 14 is positioned to surround the adjacent first insertion portions 111, second insertion portion 121, first insertion portion 112, and second insertion portion 122 around the rotation axis A.

[0029] Figures 6 to 8 show examples of coil sets and coil arrangements according to the first embodiment. The eight coils shown in Figure 6, Figure 7, or Figure 8 are divided into pairs of two coils connected in series. Furthermore, the pairs of two coils are connected in parallel.

[0030] Figure 6 shows an example in which a set containing four coils, two first coils and two fourth coils, is connected in parallel to a set containing four coils, two second coils and two third coils. Figure 6 shows the first coils 11a, 11b, 2nd coil 12a, 2nd coil 12b, 3rd coil 13a, 3rd coil 13b, 4th coil 14a, and 4th coil 14b, which are inserted into the slots of the stator core 19.

[0031] The first coil 11a, the second coil 12a, the third coil 13a, and the fourth coil 14a form a set of four coils and are connected in series. The first coil 11b, the second coil 12b, the third coil 13b, and the fourth coil 14b form a set of four coils and are connected in series. These two sets are connected in parallel.

[0032] The first coil 11a and the first coil 11b are positioned opposite each other with the rotation axis A in between. The second coil 12a is located inside the first coil 11a and is positioned closer to the rotation axis A than the first coil 11a in a direction perpendicular to the rotation axis A. The second coil 12b is located inside the first coil 11b and is positioned closer to the rotation axis A than the first coil 11b in a direction perpendicular to the rotation axis A.

[0033] The third coil 13a and the third coil 13b are positioned at a 90-degree angle relative to the first coil 11a, the first coil 11b, the second coil 12a, and the second coil 12b in the direction of the rotation axis A. The third coil 13a and the third coil 13b are positioned opposite each other with the rotation axis A in between. The fourth coil 14a is positioned inside the third coil 13a. The fourth coil 14b is positioned inside the third coil 13b.

[0034] In the example shown in Figure 6, the number of large coils and small coils in each set are equal. The large coils here are the first coil 11a, the first coil 11b, the third coil 13a, and the third coil 13b. The small coils here are the second coil 12a, the second coil 12b, the third coil 13a, and the third coil 13b. Furthermore, in the example shown in Figure 6, the coils in the set containing the first coil 11a, etc., and the coils in the set containing the second coil 12a, etc., are arranged in a relatively uniform distribution with respect to the rotation axis A.

[0035] Therefore, in the example shown in Figure 6, due to variations in the manufacturing precision and assembly precision of each component, the components are positioned unevenly with respect to the rotation axis A. As a result, the electromotive forces generated between the coils connected in parallel cancel each other out more than in the examples shown in Figures 7 and 8. Consequently, in the example shown in Figure 6, the circulating current is smaller than in the examples shown in Figures 7 and 8.

[0036] Figure 7 shows an example in which two sets, each containing one first coil, one second coil, one third coil, and one fourth coil, are connected in parallel. Figure 7 shows the first coil 11c, one first coil 11d, the second coil 12c, one second coil 12d, the third coil 13c, one third coil 13d, the fourth coil 14c, and the fourth coil 14d, which are inserted into the slots of the stator core 19.

[0037] The first coil 11c, the second coil 12c, the third coil 13c, and the fourth coil 14c form a set of four coils and are connected in series. The first coil 11d, the second coil 12d, the third coil 13d, and the fourth coil 14d form a set of four coils and are connected in series. These two sets are connected in parallel.

[0038] The first coil 11c and the first coil 11d are positioned opposite each other with the rotation axis A in between. The second coil 12c is located inside the first coil 11c and is positioned closer to the rotation axis A than the first coil 11c in a direction perpendicular to the rotation axis A. The second coil 12d is located inside the first coil 11d and is positioned closer to the rotation axis A than the first coil 11d in a direction perpendicular to the rotation axis A.

[0039] The third coil 13c and the third coil 13d are positioned at a 90-degree angle to the first coil 11c, the first coil 11d, the second coil 12c, and the second coil 12d in the direction of the rotation axis A. The third coil 13c and the third coil 13d are positioned opposite each other with the rotation axis A in between. The fourth coil 14c is positioned inside the third coil 13c. The fourth coil 14d is positioned inside the third coil 13d.

[0040] In the example shown in Figure 7, a set containing the first coil 11c, etc., is arranged on one side of the plane passing through the rotation axis A, and a set containing the first coil 11d, etc., is arranged on the other side of the same plane. In other words, in the example shown in Figure 7, the coils connected in series are arranged together on one side and the other side of the plane passing through the rotation axis A. Therefore, in the example shown in Figure 7, it is possible to shorten and simplify the busbars, jumper wires, etc., necessary for connecting the coils in series, thereby simplifying the processes and parts required for motor manufacturing and reducing the cost required for motor manufacturing.

[0041] Figure 8 shows an example in which a set containing four coils, two first coils and two third coils, is connected in parallel to a set containing four coils, two second coils and two fourth coils. Figure 8 shows the first coils 11e, 11f, 22e, 22f, 33e, 33f, 44e, and 44f, which are inserted into the slots of the stator core 19.

[0042] The first coil 11e, the first coil 11f, the third coil 13e, and the third coil 13f form one set of four coils and are connected in series. The second coil 12e, the second coil 12f, the fourth coil 14e, and the fourth coil 14f form one set of four coils and are connected in series. These two sets are connected in parallel.

[0043] The first coil 11e and the first coil 11f are disposed at positions opposing each other with the rotation axis A interposed therebetween. The second coil 12e is located inside the first coil 11e, and is disposed at a position closer to the rotation axis A than the first coil 11e in a direction perpendicular to the rotation axis A. The second coil 12f is located inside the first coil 11f, and is disposed at a position closer to the rotation axis A than the first coil 11f in a direction perpendicular to the rotation axis A.

[0044] The third coil 13e and the third coil 13f are disposed at positions shifted by 90 degrees relative to the first coil 11e, the first coil 11f, the second coil 12e, and the second coil 12f in a direction around the rotation axis A. Further, the third coil 13e and the third coil 13f are disposed at positions opposing each other with the rotation axis A interposed therebetween. The fourth coil 14e is disposed inside the third coil 13f. The fourth coil 14e is disposed inside the third coil 13f.

[0045] In the example shown in FIG. 8, the set of coils including the first coil 11e and the like and the set of coils including the second coil 12e and the like are disposed relatively uniformly dispersed with reference to the rotation axis A. However, in the example shown in FIG. 8, unlike the example shown in FIG. 6, large coils are connected in series, and small coils are connected in series. The large coils referred to herein are the first coil 11e, the first coil 11f, the third coil 13e, and the third coil 13f. Further, the small coils referred to herein are the second coil 12e, the second coil 12f, the third coil 13e, and the third coil 13f.

[0046] For this reason, in the example shown in FIG. 8, since each component is arranged offset relative to the rotation axis A due to variations in the machining accuracy, assembly accuracy and the like of each component, the electromotive force generated between the coils connected in parallel is not canceled out to a greater extent than in the example shown in FIG. 6. Therefore, in the example shown in FIG. 8, the circulating current is of the same level as in the example shown in FIG. 7.

[0047] The stator 1 according to the first embodiment has been described above. In the stator 1, the eight coils described above are divided into four sets of coils connected in series, and these two sets are connected in parallel with each other.

[0048] In the stator 1, for example, as shown in FIG. 6, a set including four coils, that is two first coils and two fourth coils, and a set including four coils, that is two second coils and two third coils, are connected in parallel. For the coils shown in FIG. 6, the number of large coils included in each set is equal to the number of small coils, and the number of large coils and the number of small coils are arranged relatively uniformly dispersed. Thereby, the coils shown in FIG. 6 can reduce the electromotive force generated between the coils connected in parallel, and can reduce the circulating current. Further, thereby, the coils shown in FIG. 6 can suppress the occurrence of loss due to circulating current that does not contribute to the torque of the motor.

[0049] In the stator 1, for example, as shown in FIG. 7, two sets each including one first coil, one second coil, one third coil and one fourth coil are connected in parallel. Thereby, the coils shown in FIG. 7 can reduce the electromotive force generated between the coils connected in parallel, and can reduce the circulating current. Further, in the stator 1, the coils connected in series are collectively arranged on one side and the other side of a plane passing through the rotation axis A. Thereby, the coils shown in FIG. 7 make it possible to make the bus bars, crossover wires and the like required for connecting the coils in series shorter and have a simple structure, simplify the processes and parts required for manufacturing the motor, and reduce the cost required for manufacturing the motor.

[0050] Furthermore, since the stator 1 is equipped with the first coil, second coil, third coil, and fourth coil described above, it is possible to make effective use of the space at the coil ends and their surroundings.

[0051] Specifically, the stator 1 allows the second coil to be positioned in the gap between the first coil, the third coil, and the fourth coil. Therefore, the stator 1 can reduce the dimensions of the coils in the direction perpendicular to the rotation axis A. Furthermore, the stator 1 allows the fourth coil to be positioned in the gap between the first coil, the second coil, and the third coil. Therefore, the stator 1 can reduce the dimensions of the coils in the direction of the rotation axis A.

[0052] On the other hand, stator 1 has larger dimensions in the direction of the rotation axis A than stator 1 which has coils made by welding a large number of U-shaped flat wires inserted into slots. In other words, stator 1 has a higher coil end height than stator 1 which has coils made by welding a large number of U-shaped flat wires inserted into slots. As a result, stator 1 increases electrical resistance and reduces the efficiency of the motor.

[0053] However, this increase in electrical resistance has little effect on the motor's efficiency in regions where the motor's torque is relatively low. Furthermore, the stator 1 can avoid increasing the dimensions in the direction of the rotation axis A by reducing the number of plate-like members forming the stator core 19 and thereby reducing the dimensions of the stator core 19 in the direction of the rotation axis A. In addition, the stator 1 can reduce the iron loss of the stator core 19 by reducing the dimensions of the stator core 19 in the direction of the rotation axis A. Moreover, in the motor according to the first embodiment, the increase in electrical resistance due to the increase in dimensions in the direction of the rotation axis A contributes less to the reduction of iron loss of the stator core 19 than to the reduction of iron loss of the stator core 19.

[0054] Furthermore, compared to a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, stator 1 can reduce the number of locations requiring welding. In addition, compared to a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, stator 1 can reduce the number of locations requiring powder coating to insulate the welded areas. Therefore, stator 1 can reduce the failure rate.

[0055] Furthermore, in a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, changing the number of turns requires changing the number of flat wires, thus requiring changes to the welding locations. Therefore, changing the number of turns in such a stator necessitates changing the specifications of the welding equipment. However, stator 1 allows the number of turns to be changed simply by changing the number of times the conductor is wound, so even when changing the number of turns, it does not require changing the specifications of the welding equipment.

[0056] In the first embodiment, the example described with reference to Figures 6 to 8 was that eight coils are divided into pairs of two coils connected in series, but the embodiment is not limited to this. The eight coils may also be divided into pairs of four coils connected in series. In this case, the pairs of four coils are connected in parallel.

[0057] (Second Embodiment) Next, a stator according to the second embodiment will be described. In the second embodiment, mainly the differences from the first embodiment will be described, and explanations of the same aspects as the first embodiment will be omitted as appropriate.

[0058] Figures 9 and 10 show examples of jumper wires according to the second embodiment. As shown in Figure 9, the stator according to the second embodiment comprises a first coil 11g, a first coil 11h, a fourth coil 14g, and a fourth coil 14h. Furthermore, as shown in Figure 10, the stator according to the second embodiment comprises a second coil 12g, a second coil 12h, a third coil 13g, and a third coil 13h.

[0059] The first coil 11g comprises a jumper wire 110g, a neutral point 11gN, and a terminal 11gT. The jumper wire 110g is an extension of the end of the conductor constituting the first coil 11g, with its tip being the neutral point 11gN. The terminal 11gT is the end of the conductor constituting the first coil 11g and is connected to the neutral point 14hN, which will be described later. The first coil 11g is the same as the first coil according to the first embodiment, except that it comprises the jumper wire 110g, the neutral point 11gN, and the terminal 11gT.

[0060] The first coil 11h comprises a jumper wire 110h, a neutral point 11hN, and a terminal 11hT. The jumper wire 110h is an extension of the end of the conductor constituting the first coil 11h, with its tip being the neutral point 11hN. The terminal 11hT is the end of the conductor constituting the first coil 11h and is connected to the neutral point 14gN, which will be described later. The first coil 11h is the same as the first coil according to the first embodiment, except that it comprises the jumper wire 110h, the neutral point 11hN, and the terminal 11hT.

[0061] The fourth coil 14g comprises a jumper wire 140g, a neutral point 14gN, and a terminal 14gT. The jumper wire 140g is an extension of the end of the conductor constituting the fourth coil 14g, with its tip being the neutral point 14gN. The terminal 14gT is the end of the conductor constituting the fourth coil 14g and is connected to the neutral point 11gN. The fourth coil 14g is the same as the fourth coil according to the first embodiment, except that it comprises a jumper wire 140g, a neutral point 14gN, and a terminal 14gT.

[0062] The fourth coil 14h comprises a jumper wire 140h, a neutral point 14hN, and a terminal 14hT. The jumper wire 140h is an extension of the end of the conductor constituting the fourth coil 14h, with its tip being the neutral point 14hN. The terminal 14hT is the end of the conductor constituting the fourth coil 14h and is connected to the neutral point 11hN. The fourth coil 14h is the same as the fourth coil according to the first embodiment, except that it comprises a jumper wire 140h, a neutral point 14hN, and a terminal 14hT.

[0063] The second coil 12g comprises a jumper wire 120g, a neutral point 12gN, and a terminal 12gT. The jumper wire 120g is an extension of the end of the conductor constituting the second coil 12g, with its tip being the neutral point 12gN. The terminal 12gT is the end of the conductor constituting the second coil 12g and is connected to the neutral point 13hN, which will be described later. The second coil 12g is the same as the second coil according to the first embodiment, except that it comprises a jumper wire 120g, a neutral point 12gN, and a terminal 12gT.

[0064] The second coil 12h comprises a jumper wire 120h, a neutral point 12hN, and a terminal 12hT. The jumper wire 120h is an extension of the end of the conductor constituting the second coil 12h, with its tip being the neutral point 12hN. The terminal 12hT is the end of the conductor constituting the second coil 12h and is connected to the neutral point 13gN, which will be described later. The second coil 12h is the same as the second coil according to the first embodiment, except that it comprises a jumper wire 120h, a neutral point 12hN, and a terminal 12hT.

[0065] The third coil 13g comprises a jumper wire 130g, a neutral point 13gN, and a terminal 13gT. The jumper wire 130g is an extension of the end of the conductor constituting the third coil 13g, with its tip being the neutral point 13gN. The terminal 13gT is the end of the conductor constituting the third coil 13g and is connected to the neutral point 12gN. The third coil 13g is the same as the third coil according to the first embodiment, except that it comprises the jumper wire 130g, the neutral point 13gN, and the terminal 13gT.

[0066] The third coil 13h comprises a jumper wire 130h, a neutral point 13hN, and a terminal 13hT. The jumper wire 130h is an extension of the end of the conductor constituting the third coil 13h, with its tip being the neutral point 13hN. The terminal 13hT is the end of the conductor constituting the third coil 13h and is connected to the neutral point 12hN. The third coil 13h is the same as the third coil according to the first embodiment, except that it comprises the jumper wire 130h, the neutral point 13hN, and the terminal 13hT.

[0067] The above description uses the example of a neutral point such as 11gN located at the end of a jumper wire, but is not limited to this. In the second embodiment, at least one of the first coil, second coil, third coil, and fourth coil may not have a jumper wire and may draw its neutral point from its own vicinity.

[0068] Furthermore, the above description uses the example where all eight coils, including the first coil 11g, have the ends of the conductors connected as jumper wires, but is not limited to this. In the second embodiment, at least one of the first coil, second coil, third coil, and fourth coil may have the ends of the conductors connected as jumper wires.

[0069] Figures 11 and 12 show examples of stator coil ends according to the second embodiment. In Figures 11 and 12, the U-phase coils are shown with dot hatching, the V-phase coils with vertical line hatching, and the W-phase coils with horizontal line hatching. Figure 11 shows an example of the stator coil end according to the second embodiment viewed from a viewpoint located on the rotation axis A. Figure 12 shows an example of the stator coil end according to the second embodiment viewed from a viewpoint located on a straight line perpendicular to the rotation axis A.

[0070] The coil ends of the stator according to the second embodiment have the structure shown in Figure 11, by applying the structures shown in Figures 9 and 10 to the U-phase coil, V-phase coil, and W-phase coil, respectively. Furthermore, as indicated by the arrows in Figure 12, the first coil, second coil, third coil, and fourth coil according to the second embodiment have the ends of the welded conductors bent in a direction perpendicular to the rotation axis A.

[0071] In the above description, the example given is that for all U-phase, V-phase, and W-phase, the ends of the wires to which all eight coils, such as the first coil, are welded are bent perpendicular to the axis of rotation, but the description is not limited to this. In the second embodiment, the ends of the wires to which at least one of the first coil, second coil, third coil, and fourth coil is welded may be bent perpendicular to the axis of rotation A.

[0072] The stator according to the second embodiment has been described above. In the second embodiment, at least one of the first coil, second coil, third coil, and fourth coil has a jumper wire at the end of the conductor. This reduces the number of places where conductors are welded or crimped together and powder-coated in the stator according to the second embodiment. Alternatively, this reduces the number of busbars or jumper wires that electrically connect the coils in the stator according to the second embodiment. Therefore, the stator according to the second embodiment can reduce the number of parts, man-hours, costs, etc. required for the manufacture of the motor.

[0073] Furthermore, in the second embodiment, the end of the wire to which at least one of the first coil, second coil, third coil, and fourth coil is welded is bent in a direction perpendicular to the rotation axis A. As a result, the stator according to the second embodiment can reduce the dimensions of the motor in the direction of the rotation axis A.

[0074] (Third Embodiment) The stator according to the third embodiment is mounted on a motor having an odd number of pole pairs. The motor according to the third embodiment has 6 poles and 36 slots, with the number of slots per pole per phase being q = 2. The number of slots per pole per phase is the value obtained by dividing the number of slots formed in the stator core by the product of the number of poles and the number of phases of the motor. Therefore, the motor according to the third embodiment has 6 poles and 3 phases.

[0075] Figure 13 shows an example of a stator according to the third embodiment. In Figure 13, the U-phase coils are shown with dot hatching, the V-phase coils with vertical line hatching, and the W-phase coils with horizontal line hatching. The stator 2 is cylindrical with the rotor's rotation axis B as its central axis, and the rotor is inserted inside. As shown in Figure 13, the stator 2 also includes a first coil 21, a second coil 22, a third coil 23, a fourth coil 24, a fifth coil 25, a sixth coil 26, and a stator core 29.

[0076] The first coil 21, second coil 22, third coil 23, fourth coil 24, fifth coil 25, and sixth coil 26 are electrically connected by busbars, jumper wires, etc., to form the coils of the motor, including the stator 2. The first coil 21, second coil 22, third coil 23, fourth coil 24, fifth coil 25, and sixth coil 26 are formed from conductors such as flat rectangular wires. The stator core 29 is manufactured by stacking plate-shaped members made of electromagnetic steel in the direction of the rotation axis B.

[0077] As shown in Figure 13, the U-phase of the coil according to the third embodiment is formed by two sets of the first coil 21 and the second coil 22, and one set of the third coil 23 and the fourth coil 24. As shown in Figure 13, the V-phase of the coil according to the third embodiment is formed by one set of the first coil 21 and the second coil 22, and two sets of the third coil 23 and the fourth coil 24. As shown in Figure 13, the W-phase of the coil according to the third embodiment is formed by one set of the first coil 21 and the second coil 22, one set of the third coil 23 and the fourth coil 24, and one set of the fifth coil 25 and the sixth coil 26.

[0078] Figure 14 shows examples of the first and second coils according to the third embodiment. As shown in Figure 14, the first coil 21 includes a first insertion portion 211, a first insertion portion 212, a first bridge portion 213, and a first bridge portion 214.

[0079] The first insertion portion 211 and the first insertion portion 212 are the parts of the first coil 21 that are inserted into the slots of the stator core 29. The first bridge portion 213 is the part of the first coil 21 that connects one end of the first insertion portion 211 and one end of the first insertion portion 212. When the first insertion portion 211 and the first insertion portion 212 are inserted into the slots, the first bridge portion 213 has a surface 213P at the coil end that follows a virtual cylinder that includes the entire outer surface of the stator core 29. Here, the virtual cylinder is a cylinder that extends the outer surface of the stator core 29 on both sides in the direction of the rotation axis B. The surface 213P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. The surface 213P is formed of a conductor such as a flat rectangular wire. The first bridge portion 214 is the part of the first coil 21 that connects the other end of the first insertion portion 211 and the other end of the first insertion portion 212. The first bridge portion 214 has a surface 214P that, when the first insertion portion 211 and the first insertion portion 212 are inserted into the slot, is aligned with a virtual cylinder at the coil end that includes the entire outer surface of the stator core 29. The surface 214P does not have to be entirely parallel to the virtual cylinder, or at least a portion of it may be parallel to the virtual cylinder. The surface 214P is formed of a conductor such as a flat rectangular wire.

[0080] The coil ends described above are regions located on both sides in the direction of the rotation axis B of the stator core 29. The coil ends include the first bridge section 213, the first bridge section 214, the second bridge section 223, the second bridge section 224 (described later), the third bridge section 233, the third bridge section 234, etc. The coil ends also include the fourth bridge section 243, the fourth bridge section 244, the fifth bridge section 253, the fifth bridge section 254, the sixth bridge section 263, the sixth bridge section 264, etc. (described later). The virtual cylinder described above is the side surface of a right circular column with the rotation axis B as its central axis and a diameter equal to the outer surface of the stator core 29.

[0081] As shown in Figure 14, the second coil 22 includes a second insertion portion 221, a second insertion portion 222, a second bridge portion 223, and a second bridge portion 224.

[0082] The second insertion portion 221 and the second insertion portion 222 are the parts of the second coil 22 that are inserted into the slots of the stator core 29. The distance between the second insertion portion 221 and the second insertion portion 222 is narrower than the distance between the first insertion portion 211 and the first insertion portion 212 of the first coil 21. The second insertion portion 221 is inserted into the slot one position inward from the slot in which the first insertion portion 211 of the first coil 21 is inserted. The second insertion portion 222 is inserted into the slot one position inward from the slot in which the first insertion portion 212 of the first coil 21 is inserted.

[0083] Furthermore, as shown in Figure 13, the stator 2 has three structures in which a third insertion part 231, a fourth insertion part 241, a third insertion part 232, and a fourth insertion part 242 are arranged between the second insertion part 221 and the second insertion part 222, adjacent in the direction around the rotation axis B. Alternatively, as shown in Figure 13, the stator 2 has one structure in which a third insertion part 231, a fourth insertion part 241, a fifth insertion part 252, and a sixth insertion part 262 are arranged between the second insertion part 221 and the second insertion part 222, adjacent in the direction around the rotation axis B.

[0084] The second bridge portion 223 is the part of the second coil 22 that connects one end of the second insertion portion 221 and one end of the second insertion portion 222. When the second insertion portions 221 and 222 are inserted into the slot, the second bridge portion 223 has a surface 223P at the coil end that follows a virtual cylinder including the entire outer surface of the stator core 29. The surface 223P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. The surface 223P is formed of a conductor such as a flat rectangular wire. Furthermore, the height of the second bridge portion 223 in the direction perpendicular to the rotation axis B is lower than that of the first bridge portion 213 of the first coil 21. Specifically, the height of the surface 223P of the second bridge portion 223 in the direction perpendicular to the rotation axis B is lower than that of the surface 213P of the first bridge portion 213.

[0085] The second bridge portion 224 is the part of the second coil 22 that connects the other end of the second insertion portion 221 to the other end of the second insertion portion 222. When the second insertion portions 221 and 222 are inserted into the slot, the second bridge portion 224 has a surface 224P at the coil end that follows a virtual cylinder including the entire outer surface of the stator core 29. The surface 224P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. The surface 224P is formed of a conductor such as a flat rectangular wire. Furthermore, the height of the second bridge portion 224 in the direction perpendicular to the rotation axis B is lower than that of the first bridge portion 214 of the first coil 21. Specifically, the height of the surface 224P of the second bridge portion 224 in the direction perpendicular to the rotation axis B is lower than that of the surface 214P of the first bridge portion 214.

[0086] Figure 15 shows examples of the third and fourth coils according to the third embodiment. As shown in Figure 15, the third coil 23 includes a third insertion portion 231, a third insertion portion 232, a third bridge portion 233, and a third bridge portion 234.

[0087] The third insertion portion 231 and the third insertion portion 232 are the parts of the third coil 23 that are inserted into the slots of the stator core 29. The third bridge portion 233 is the part of the third coil 23 that connects one end of the third insertion portion 231 and one end of the third insertion portion 232. When the third insertion portion 231 and the third insertion portion 232 are inserted into the slots, the third bridge portion 233 has a surface 233P that aligns with the end face perpendicular to the rotation axis B of the stator core 29 at the coil end. The surface 233P does not have to be entirely parallel to the virtual cylinder, or at least a part of it may be parallel to the virtual cylinder. The surface 233P is formed of a conductor such as a flat rectangular wire. The third bridge portion 234 is the part of the third coil 23 that connects the other end of the third insertion portion 231 and the other end of the third insertion portion 232. The third bridge portion 234 has a surface 234P that aligns with the end face perpendicular to the rotation axis B of the stator core 29 at the coil end when the third insertion portion 231 and the third insertion portion 232 are inserted into the slot. The surface 234P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The surface 234P is formed of a conductor such as a flat rectangular wire.

[0088] As shown in Figure 15, the fourth coil 24 comprises a fourth insertion portion 241, a fourth insertion portion 242, a fourth bridge portion 243, and a fourth bridge portion 244.

[0089] The fourth insertion portion 241 and the fourth insertion portion 242 are the parts of the fourth coil 24 that are inserted into the slots of the stator core 29. The distance between the fourth insertion portion 241 and the fourth insertion portion 242 is narrower than the distance between the third insertion portion 231 and the third insertion portion 232 of the third coil 23. The fourth insertion portion 241 is inserted into the slot one position inward from the slot in which the third insertion portion 231 of the third coil 23 is inserted. The fourth insertion portion 242 is inserted into the slot one position inward from the slot in which the third insertion portion 232 of the third coil 23 is inserted.

[0090] Furthermore, as shown in Figure 13, the stator 2 has three structures in which the first insertion portion 211, the second insertion portion 221, the first insertion portion 212, and the second insertion portion 222 are arranged between the fourth insertion portion 241 and the fourth insertion portion 242 in the direction of rotation axis B. Alternatively, as shown in Figure 13, the stator 2 has one structure in which the first insertion portion 212, the second insertion portion 222, the fifth insertion portion 251, and the sixth insertion portion 261 are arranged between the fourth insertion portion 241 and the fourth insertion portion 242 in the direction of rotation axis B.

[0091] The fourth bridge portion 243 is the part of the fourth coil 24 that connects one end of the fourth insertion portion 241 to one end of the fourth insertion portion 242. When the fourth insertion portion 241 and the fourth insertion portion 242 are inserted into the slot, the fourth bridge portion 243 has a surface 243P that aligns with the end face perpendicular to the rotation axis B of the stator core 29 at the coil end. The surface 243P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. The surface 243P is formed of a conductor such as a flat rectangular wire. The fourth bridge portion 244 is the part of the fourth coil 24 that connects the other end of the fourth insertion portion 241 to the other end of the fourth insertion portion 242. When the fourth insertion portion 241 and the fourth insertion portion 242 are inserted into the slot, the fourth bridge portion 244 has a surface 244P that aligns with the end face perpendicular to the rotation axis B of the stator core 29 at the coil end. The surface 244P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. Also, the surface 244P is formed by a conductor such as a flat rectangular wire. The distance between the fourth bridge section 243 and the fourth bridge section 244 is narrower than the distance between the third bridge section 233 and the third bridge section 234.

[0092] Figure 16 shows examples of the fifth and sixth coils according to the third embodiment. As shown in Figure 16, the fifth coil 25 comprises a fifth insertion portion 251, a fifth insertion portion 252, a fifth bridge portion 253, and a fifth bridge portion 254.

[0093] The fifth insertion portion 251 and the fifth insertion portion 252 are the parts of the fifth coil 25 that are inserted into the slots of the stator core 29.

[0094] The fifth bridge portion 253 is the part of the fifth coil 25 that connects one end of the fifth insertion portion 251 to one end of the fifth insertion portion 252. The fifth bridge portion 253 comprises a surface 253P and a surface 253Q. Surfaces 253P and 253Q are formed from a conductor such as a flat rectangular wire. As shown in Figure 13, when the fifth insertion portion 251 and the fifth insertion portion 252 are inserted into the slot, surface 253P follows a virtual cylinder at the coil end that includes the entire outer surface of the stator core 29. Surface 253P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. As shown in Figure 13, when the fifth insertion portion 251 and the fifth insertion portion 252 are inserted into the slot, surface 253Q follows the end face of the stator core 29 perpendicular to the rotation axis B at the coil end. Surface 253Q does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. Furthermore, as shown in Figure 13, surfaces 253P and 253Q are in a twisted position.

[0095] The fifth bridge portion 254 is the part of the fifth coil 25 that connects the other end of the fifth insertion portion 251 to the other end of the fifth insertion portion 252. The fifth bridge portion 254 comprises a surface 254P and a surface 254Q. Surfaces 254P and 254Q are formed from a conductor such as a flat rectangular wire. As shown in Figure 13, when the fifth insertion portion 251 and the fifth insertion portion 252 are inserted into the slot, surface 254P follows a virtual cylinder at the coil end that includes the entire outer surface of the stator core 29. Surface 254P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. As shown in Figure 13, when the fifth insertion portion 251 and the fifth insertion portion 252 are inserted into the slot, surface 254Q follows the end face of the stator core 29 perpendicular to the rotation axis B at the coil end. Surface 254Q does not have to be entirely parallel to the virtual cylinder, or at least a portion of it may be parallel to the virtual cylinder. Also, surfaces 254P and 254Q are in a twisted position, as shown in Figure 13.

[0096] As shown in Figure 16, the sixth coil 26 comprises a sixth insertion portion 261, a sixth insertion portion 262, a sixth bridge portion 263, and a sixth bridge portion 264.

[0097] The sixth insertion portion 261 and the sixth insertion portion 262 are the parts of the sixth coil 26 that are inserted into the slots of the stator core 29. The distance between the sixth insertion portion 261 and the sixth insertion portion 262 is narrower than the distance between the fifth insertion portion 251 and the fifth insertion portion 252 of the fifth coil 25. The sixth insertion portion 261 is inserted into the slot one position inward from the slot in which the fifth insertion portion 251 of the fifth coil 25 is inserted. The sixth insertion portion 262 is inserted into the slot one position inward from the slot in which the fifth insertion portion 252 of the fifth coil 25 is inserted.

[0098] Furthermore, as shown in Figure 13, the stator 2 has a structure in which the first insertion portion 211, the second insertion portion 221, the third insertion portion 232, and the fourth insertion portion 242 are arranged between the sixth insertion portion 261 and the sixth insertion portion 262.

[0099] The sixth bridge portion 263 is the part of the sixth coil 26 that connects one end of the sixth insertion portion 261 to one end of the sixth insertion portion 262. The sixth bridge portion 263 comprises a surface 263P and a surface 264Q. Surfaces 263P and 263Q are formed from a conductor such as a flat rectangular wire. As shown in Figure 13, when the sixth insertion portion 261 and the sixth insertion portion 262 are inserted into the slot, surface 263P follows a virtual cylinder at the coil end that includes the entire outer surface of the stator core 29. Surface 263P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. As shown in Figure 13, when the sixth insertion portion 261 and the sixth insertion portion 262 are inserted into the slot, surface 263Q follows the end face of the stator core 29 perpendicular to the rotation axis B at the coil end. Surface 263Q does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. Furthermore, as shown in Figure 13, surfaces 263P and 263Q are in a twisted position. Surface 263P has a lower height than the fifth coil 25 in the direction perpendicular to the rotation axis B. Specifically, surface 263P has a lower height than surface 253P of the fifth coil 25 in the direction perpendicular to the rotation axis B.

[0100] The sixth bridge portion 264 is the part of the sixth coil 26 that connects the other end of the sixth insertion portion 261 to the other end of the sixth insertion portion 262. The sixth bridge portion 264 comprises a surface 264P and a surface 264Q. Surfaces 264P and 264Q are formed from a conductor such as a flat rectangular wire. As shown in Figure 13, when the sixth insertion portion 261 and the sixth insertion portion 262 are inserted into the slot, surface 264P follows a virtual cylinder at the coil end that includes the entire outer surface of the stator core 29. Surface 264P does not have to be parallel to the virtual cylinder as a whole, or at least a part of it may be parallel to the virtual cylinder. As shown in Figure 13, when the sixth insertion portion 261 and the sixth insertion portion 262 are inserted into the slot, surface 264Q follows the end face of the stator core 29 perpendicular to the rotation axis B at the coil end. Surface 264Q does not have to be entirely parallel to the virtual cylinder, or at least a portion of it may be parallel to the virtual cylinder. Also, surfaces 264P and 264Q are in a twisted position, as shown in Figure 13. Surface 264P has a height lower than that of the fifth coil 25 in the direction perpendicular to the rotation axis B. Specifically, surface 264P has a height lower than that of surface 254P of the fifth coil 25 in the direction perpendicular to the rotation axis B.

[0101] Furthermore, the distance between surface 263Q and surface 264Q is narrower than that between the fifth coil 25. Specifically, the distance between surface 263Q and surface 264Q is narrower than the distance between surface 253Q and surface 254Q.

[0102] The stator 2 according to the third embodiment has been described above. Since the stator 2 includes a first coil 21, a second coil 22, a third coil 23, and a fourth coil 24, it is possible to effectively utilize the space at the coil ends and their surroundings.

[0103] Specifically, the stator 2 allows the second coil 22 to be positioned in the gap between the first coil 21, the third coil 23, and the fourth coil. Therefore, the stator 2 can reduce the dimensions of the coils in the direction perpendicular to the rotation axis B. Furthermore, the stator 2 allows the fourth coil 24 to be positioned in the gap between the first coil 21, the second coil 22, and the third coil 23. Therefore, the stator 2 can reduce the dimensions of the coils in the direction of the rotation axis B.

[0104] Furthermore, since the stator 2 includes a fifth coil 25 and a sixth coil 26, even if the number of magnetic pole pairs in the motor according to the third embodiment is odd, it is possible to avoid both a shortage and an excess of slots.

[0105] Furthermore, since the stator 2 includes a fifth coil 25 and a sixth coil 26, it is possible to make effective use of the space at the coil ends and their surroundings.

[0106] Specifically, the stator 2 allows the sixth coil 26 to be positioned in the gap between the fifth coil 25, the third coil 23, and the fourth coil 24. Furthermore, the stator 2 allows the fourth coil 24 to be positioned in the gap between the fifth coil 25, the sixth coil 26, and the third coil 23. Therefore, the stator 2 can reduce the dimensions of the coils in the direction perpendicular to the rotation axis B and in the direction of the rotation axis B.

[0107] On the other hand, the stator 2 has a larger dimension in the direction of the rotation axis B than the coil made by welding a large number of U-shaped flat wires inserted into the slots. In other words, the height of the coil end of the stator 2 is greater than that of the coil made by welding a large number of U-shaped flat wires inserted into the slots. As a result, the stator 2 increases electrical resistance and reduces the efficiency of the motor.

[0108] However, this increase in electrical resistance has little effect on the motor's efficiency in regions where the motor's torque is relatively low. Furthermore, the stator 2 can avoid increasing the dimensions in the direction of the rotation axis B by reducing the number of plate-like members forming the stator core 29 and thereby reducing the dimensions of the stator core 29 in the direction of the rotation axis B. In addition, the stator 2 can reduce the iron loss of the stator core 29 by reducing the dimensions of the stator core 29 in the direction of the rotation axis B. Moreover, in the motor according to the third embodiment, the increase in electrical resistance due to the increase in dimensions in the direction of the rotation axis B contributes less to the reduction of iron loss of the stator core 29 than to the reduction of iron loss of the stator core 29.

[0109] Furthermore, compared to a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, stator 2 can reduce the number of locations requiring welding. In addition, compared to a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, stator 2 can reduce the number of locations requiring powder coating to insulate the welded areas. Therefore, stator 2 can reduce the failure rate.

[0110] Furthermore, in a stator having a coil made by inserting U-shaped flat wires into slots and welding the ends of different flat wires together, changing the number of turns requires changing the number of flat wires, thus requiring changes to the welding locations. Therefore, changing the number of turns in this stator necessitates changing the specifications of the welding equipment. However, stator 2 allows changing the number of turns simply by changing the number of times the conductor is wound, so even when changing the number of turns, it does not require changing the specifications of the welding equipment.

[0111] In the third embodiment described above, a motor with 6 poles and 36 slots, and a number of slots per pole and per phase q = 2 was used as an example, but the motor is not limited to this. The number of poles, the number of slots, and the number of slots per pole and per phase q of the motor according to the third embodiment are not particularly limited as long as the number of magnetic pole pairs is odd. For example, the motor according to the third embodiment may have 6 poles, 54 slots, and a number of slots per pole and per phase q = 3.

[0112] In the embodiments described above, the example of a rotating electric machine being a motor was used, but the embodiment is not limited to this. The rotating electric machine in the embodiment may be, for example, a generator.

[0113] Preferred embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. That is, the present invention includes embodiments that have been modified, substituted, or redesigned in accordance with the spirit of the present invention, and these embodiments are not excluded.

[0114] 1, 2... Stator, 11, 21... First coil, 12, 22... Second coil, 13, 23... Third coil, 14, 24... Fourth coil, 25... Fifth coil, 26... Sixth coil, A, B... Rotating shaft

Claims

1. A first coil having two first insertion portions inserted into a slot and two first bridge portions at the coil end that follow a virtual cylinder including the entire outer surface of the stator core; a second coil having two second insertion portions inserted into a slot and spaced closer together than the spacing between the two first insertion portions, and two second bridge portions at the coil end that follow the virtual cylinder and have a height lower than the first bridge portions in a direction perpendicular to the rotation axis of the rotating electric machine; a third coil having two third insertion portions inserted into a slot and two third bridge portions at the coil end that follow the end face of the stator core perpendicular to the rotation axis; a fourth coil having two fourth insertion portions inserted into a slot and spaced closer together than the spacing between the two third insertion portions, and two fourth bridge portions at the coil end that follow the end face and have a spacing narrower than the spacing between the two third bridge portions; A stator in which two first coils, two second coils, two third coils, and two fourth coils are connected in series to form sets of two coils or sets of four coils, and these sets of two coils or these sets of four coils are connected in parallel.

2. The stator according to claim 1, wherein a set of four, each consisting of two first coils and two fourth coils, and a set of four, each consisting of two second coils and two third coils, are connected in parallel.

3. The stator according to claim 1, wherein two sets, each containing one of the first coil, the second coil, the third coil, and the fourth coil, are connected in parallel.

4. The stator according to claim 1, wherein at least one of the first coil, the second coil, the third coil, and the fourth coil has a jumper wire at the end of the conductor.

5. The stator according to claim 1, wherein at least one of the first coil, the second coil, the third coil, and the fourth coil has the end of the welded wire bent perpendicular to the axis of rotation.

6. A rotating electric machine comprising a stator according to any one of claims 1 to 5.

7. A first coil having two first insertion portions inserted into a slot and two first bridge portions at the coil end that follow a virtual cylinder including the entire outer surface of the stator core; a second coil having two second insertion portions inserted into a slot and spaced closer together than the spacing between the two first insertion portions, and two second bridge portions at the coil end that follow the virtual cylinder and have a height lower than the first bridge portions in a direction perpendicular to the rotation axis of the rotating electric machine; a third coil having two third insertion portions inserted into a slot and two third bridge portions at the coil end that follow the end face of the stator core perpendicular to the rotation axis; a fourth coil having two fourth insertion portions inserted into a slot and spaced closer together than the spacing between the two third insertion portions, and two fourth bridge portions at the coil end that follow the end face and have a spacing narrower than the spacing between the two third bridge portions; a fifth coil having two fifth insertion portions inserted into a slot and two fifth bridge portions at the coil end that have a surface along the virtual cylinder and a surface along the end face; A stator comprising: two sixth insertion portions inserted into a slot and spaced closer together than the spacing between the two fifth insertion portions; and a sixth coil having a surface along the virtual cylinder and a surface along the end face at the coil end, wherein the height of the surface along the virtual cylinder in the direction perpendicular to the rotation axis is lower than that of the fifth coil, and the spacing between the surfaces along the end face is narrower than that of the fifth coil.

8. The stator according to claim 7, wherein the number of magnetic pole pairs is odd.

9. A rotating electric machine comprising the stator according to claim 7 or claim 8.

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