Rotating electric machine

Abstract

The present invention provides a rotating electric machine that can improve the space factor of coils in a slot by reducing the potential difference between segment coils arranged within the same slot. [Solution] The rotating electric machine has the following features: (a) In a three-phase coil, three segment coils of the same phase are inserted into the outer circumference of one set of slots that are adjacent in the circumferential direction from among a plurality of slots, and three segment coils are inserted into the inner circumference of another set of slots that are shifted by one slot in the circumferential direction from that set of slots; (b) The U-phase coil 40, V-phase coil 50, and W-phase coil 60 each have an inner winding portion with an outer circumferential layer connection portion Ro connected in the first and second layers so that the segment coils rotate in the circumferential direction; and (c) Regarding the connection order of the segment coils from the input terminal side of each phase, the connection to the segment coils inserted in the third and fourth layers is after the connection to the outer circumferential layer connection portion Ro in the inner winding portion.

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine including a distributed-winding three-phase coil in which six segment coils are inserted into each of the slots of a stator core having a plurality of slots.

Background Art

[0002] A rotating electrical machine is known that includes a distributed-winding three-phase coil in which six coils are inserted into each of the slots of a stator core having a plurality of slots. For example, the one described in Patent Document 1 is such a machine. In the rotating electrical machine described in Patent Document 1, a stator is manufactured by, for example, a method in which a mesh-like coil having no welded portion is prepared in advance, and then the coil is expanded on the inner peripheral side of the stator core and inserted into the slots. Such a manufacturing method requires large-scale manufacturing equipment. Further, since the coils are expanded on the inner peripheral side of the stator core and inserted into the slots, it is necessary to widen the opening on the inner peripheral side of the slots in the circumferential direction. This tends to lower the space factor of the coils in the slots. Here, the "space factor" refers to the ratio [%] of the total cross-sectional area of the metal portions of the coils to the effective cross-sectional area of the slots. In addition, there is a risk that the NV (Noise Vibration) performance will deteriorate due to the coils vibrating within the slots during operation of the rotating electrical machine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] By the way, compared to the rotating electric machine described in Patent Document 1, a method can be considered in which a distributed winding three-phase coil is wound using a segment coil having a pair of arms and a connecting part that connects the bases of the pair of arms, in order to improve the space factor and suppress the deterioration of NV performance. For example, in the method using segment coils, after a segment coil is inserted into each of a plurality of slots, the three-phase coil is wound by welding one end of each of the pair of arms of the segment coils inserted into different slots to each other. In this method using segment coils, in order to further improve the space factor, it is effective to make the insulating coating of the segment coil thinner, but the thickness of the insulating coating needs to be set according to the potential difference between segment coils arranged in the same slot. That is, the smaller the potential difference between segment coils arranged in the same slot, the thinner the insulating coating of the segment coil can be made to improve the space factor.

[0005] The present invention was made against the above circumstances, and its objective is to provide a rotating electric machine that can improve the space factor of coils in a slot by reducing the potential difference between segment coils arranged in the same slot. [Means for solving the problem]

[0006] The gist of the first invention is a rotating electric machine comprising: a stator core that is cylindrical in shape and extends in the axial direction and has a plurality of slots; a distributed winding three-phase coil in which six segment coils, each having a pair of arms and a connecting portion that connects the bases of the pair of arms, are inserted into each of the plurality of slots, and one end of each pair of arms of the segment coils inserted into different slots is welded to each other; and a rotor provided on the inner circumference side of the stator core, wherein (a) the number of slots is six times the number of poles of the rotor, and (b) when the insertion positions of the six segment coils inserted into each of the plurality of slots are designated as the 1st layer, 2nd layer, 3rd layer, 4th layer, 5th layer, and 6th layer from the outer circumference side to the inner circumference side, the segment coils of the same phase in the three-phase coil are arranged from the 1st layer to the 3rd layer on the outer circumference side of a pair of slots that are adjacent in the circumferential direction among the plurality of slots (c) Three segments are inserted into each of the first and second layers, and three segments are inserted into each of the fourth to sixth layers on the inner circumference side of the other set of slots, which are offset by one slot in the circumferential direction from the first set of slots. (d) Each phase coil in the three-phase coil has an inner winding portion to which the segment coils are connected from the outer circumference to the inner circumference, an outer winding portion to which the segment coils are connected from the inner circumference to the outer circumference, and a connecting portion that connects the inner end of the inner winding portion to the inner end of the outer winding portion. (e) The inner winding portion and the outer winding portion each have an outer circumference layer connecting portion to which the segment coils are connected in the circumferential direction in the first and second layers, respectively.

[0007] The gist of the second invention is that, in the first invention, the inner winding portion and the outer winding portion each have an inner circumferential layer connecting portion connected in the fifth and sixth layers so that the segment coil rotates in the circumferential direction, an intermediate layer connecting portion connected in the third and fourth layers so that the segment coil rotates in the circumferential direction, an outer circumferential layer side transfer portion connecting the end of the outer circumferential layer connecting portion and the end of the intermediate layer connecting portion, and an inner circumferential layer side transfer portion connecting the end of the inner circumferential layer connecting portion and the end of the intermediate layer connecting portion.

[0008] The gist of the third invention is that, in the second invention, the direction in which the outer peripheral layer connection portion, the intermediate layer connection portion, and the inner peripheral layer connection portion in the inner winding portion rotate in the circumferential direction is the same.

[0009] The gist of the fourth invention is that, in the second or third invention, in the inner circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion, the direction in which the segment coil in the inner winding portion rotates in the circumferential direction and the direction in which the segment coil in the outer winding portion rotates in the circumferential direction are opposite to each other.

[0010] The gist of the fifth invention is that, in any one of the second to fourth inventions, (a) in the outer peripheral layer connection portion and the inner peripheral layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 6 in both cases; (b) in the intermediate layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 5 on one side and 7 on the other; and (c) in the outer peripheral layer transfer portion and the inner peripheral layer transfer portion, the number of circumferential slots on either the connecting portion side or the tip portion side of the segment coil is 6.

[0011] The gist of the sixth invention is that, in any one of the first to fifth inventions, in a plurality of slots, the winding start position of the outer peripheral layer connection portion in the inner winding portion of the phase coil is set at a predetermined position such that the maximum value of the voltage difference between the segment coil inserted in the third layer and the segment coil inserted in the fourth layer of different phases within the same slot is reduced.

[0012] The gist of the seventh invention is that, in any one of the first to sixth inventions, (a) the three-phase coil is Y-connected, (b) a first coil section and a second coil section are provided between the input terminal and the neutral point of the phase coil, respectively, connected in parallel, and (c) the connection structure of the segment coils within the phase coil is the same for each phase.

[0013] The gist of the eighth invention is that, in the seventh invention, the phase coils in the three-phase coil are such that, in the first coil section and the second coil section, the segment coils, which have the same connection order from the input terminal side of the phase coils, are inserted into circumferentially adjacent slots.

[0014] The gist of the ninth invention is that, in any one of the first to sixth inventions, (a) the three-phase coil is Y-connected, (b) one coil section is provided between the input terminal and the neutral point of the phase coil, (c) the phase coil has two internal winding sections, two external winding sections, and two connecting sections, and (d) the connection structure of the segment coils within the phase coil is the same for each phase.

[0015] The gist of the 10th invention is that, in the 9th invention, the phase coil in the three-phase coil is such that (a) in each of the two inner windings, the segment coils having the same connection order from the input terminal side are inserted into circumferentially adjacent slots, and (b) in each of the two outer windings, the segment coils having the same connection order from the input terminal side are inserted into circumferentially adjacent slots. [Effects of the Invention]

[0016] According to the rotating electric machine of the first invention, (a) the number of slots is six times the number of poles of the rotor, and (b) when the insertion positions of the segment coils, six of which are inserted into each of the plurality of slots, are designated as the 1st layer, 2nd layer, 3rd layer, 4th layer, 5th layer, and 6th layer from the outer circumference to the inner circumference, the segment coils of the same phase in the three-phase coil are inserted three times each from the 1st to the 3rd layer on the outer circumference side of one set of slots that are adjacent in the circumferential direction among the plurality of slots, and three times each from the 4th to the 6th layer on the inner circumference side of another set of slots that are shifted by one slot in the circumferential direction relative to the set of slots, and (c) the three-phase coil Each phase coil in a three-phase coil has an inner winding portion to which the segment coils are connected from the outer circumference to the inner circumference, an outer winding portion to which the segment coils are connected from the inner circumference to the outer circumference, and a connecting portion that connects the inner end of the inner winding portion to the inner end of the outer winding portion. (d) The inner winding portion and the outer winding portion each have an outer layer connecting portion to which the segment coils are connected in the first and second layers so as to rotate in the circumferential direction. (e) Regarding the connection order of the segment coils from the input terminal side of the phase coil, the connection to the segment coil inserted in the third layer and the connection to the segment coil inserted in the fourth layer are made after the outer layer connecting portion of the inner winding portion. In a three-phase coil, when segment coils of the same phase are adjacent within the same slot, the greater the difference in the connection order from the common input terminal side of those adjacent segment coils, the greater the voltage applied between these adjacent segment coils. In a three-phase coil, when segment coils of different phases are adjacent within the same slot, the smaller the sum of the connection sequences from the input terminal side of each phase of these adjacent segment coils, the greater the voltage applied between these adjacent segment coils. In this invention, the maximum voltage difference between adjacent segment coils in the same slot occurs when segment coils of different phases are adjacent within the same slot in a three-phase coil.With the configuration in (b) above, segment coils of different phases are adjacent within the same slot only when the segment coil inserted in the third layer and the segment coil inserted in the fourth layer are adjacent. With the configurations in (c) to (e) above, regarding the connection order of the segment coils from the input terminal side of each phase, the connection to the segment coil inserted in the third layer is made after the connection to the outer layer of the inner winding. Similarly, regarding the connection order of the segment coils from the input terminal side of each phase, the connection to the segment coil inserted in the fourth layer is made after the connection to the outer layer of the inner winding. As a result, the impedance between the adjacent segment coil inserted in the third layer and the segment coil inserted in the fourth layer is reduced according to the number of segment coils connected at the outer layer connection of the inner winding, as viewed from the input terminal side of each phase. Therefore, with the configurations in (c) to (e), the maximum value of the impedance between adjacent segment coils of different phases within the same slot is smaller compared to the case without these configurations. When the maximum value of the impedance is smaller, the maximum value of the voltage difference between adjacent segment coils of different phases within the same slot is also smaller. Therefore, the insulating coating of the segment coil can be thinned to improve the packing factor. This makes it possible, for example, to reduce the size of a rotating electric machine while maintaining the same performance, or to improve the performance of a rotating electric machine while maintaining the same size.

[0017] According to the rotating electric machine of the second invention, in the first invention, the inner winding portion and the outer winding portion each have an inner circumferential layer connecting portion connected so that the segment coil rotates circumferentially in the fifth and sixth layers, an intermediate layer connecting portion connected so that the segment coil rotates circumferentially in the third and fourth layers, an outer circumferential layer side transfer portion connecting the end of the outer circumferential layer connecting portion and the end of the intermediate layer connecting portion, and an inner circumferential layer side transfer portion connecting the end of the inner circumferential layer connecting portion and the end of the intermediate layer connecting portion. Thus, the inner winding portion and the outer winding portion each have an outer circumferential layer connecting portion, an intermediate layer connecting portion, an inner circumferential layer connecting portion, an outer circumferential layer side transfer portion, and an inner circumferential layer side transfer portion. As a result, by appropriately increasing or decreasing the number of circumferential slots in the outer circumferential layer connecting portion, the intermediate layer connecting portion, and the inner circumferential layer connecting portion, a distributed winding three-phase coil corresponding to the number of slots which is six times the number of poles of the rotor can be easily constructed.

[0018] According to the rotating electric machine of the third invention, in the second invention, the direction in which the outer circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion in the inner winding portion rotate in the same direction. When the direction in which the outer circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion in the inner winding portion rotate in the same direction, the bending direction in the circumferential direction of the segment coil can be unified to be the same in the outer circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion, compared to when they are not. As a result, the bending and welding processes of the segment coil become a repeating pattern, improving the workability of the winding process of the three-phase coil.

[0019] According to the rotating electric machine of the fourth invention, in the second or third invention, in the inner circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion, the direction in which the segment coil rotates circumferentially in the inner winding portion and the direction in which the segment coil rotates circumferentially in the outer winding portion are opposite to each other. This allows the inner winding portion and the outer winding portion to have a simple double helix configuration. For example, the bending and welding processes of the segment coils become a repeating pattern, improving the workability of the winding process of the three-phase coil.

[0020] According to the rotating electric machine of the fifth invention, in any one of the second to fourth inventions, (a) in the outer peripheral layer connection portion and the inner peripheral layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 6 in both cases; (b) in the intermediate layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 5 on one side and 7 on the other; and (c) in the outer peripheral layer transfer portion and the inner peripheral layer transfer portion, the number of circumferential slots on either the connecting portion side or the tip portion side of the segment coil is 6. By using a segment coil with the above configurations (a) to (c), the segment coils of the same phase in a three-phase coil are arranged so that 3 segment coils are inserted on the outer peripheral side of a pair of slots that are adjacent in the circumferential direction from among a plurality of slots, and 3 segment coils are inserted on the inner peripheral side of another pair of slots that are shifted by one slot in the circumferential direction relative to the pair of slots. Furthermore, the types of segment coils that differ in the number of circumferential slot pitches on the connecting end and the number of circumferential slot pitches on the tip end are limited.

[0021] According to the rotating electric machine of the sixth invention, in any one of the first to fifth inventions, in a plurality of slots, the winding start position of the outer peripheral layer connection portion in the inner winding portion of the phase coil is set at a predetermined position such that the maximum voltage difference between the segment coil inserted in the third layer and the segment coil inserted in the fourth layer of different phases within the same slot is reduced. By setting the winding start position of the outer peripheral layer connection portion in the inner winding portion of the phase coil at a predetermined position, the maximum voltage difference between the segment coil inserted in the third layer and the segment coil inserted in the fourth layer of different phases within the same slot is further reduced. As a result, the insulating coating of the segment coil can be made even thinner, improving the space factor, which makes it possible to reduce the size of the rotating electric machine while maintaining the same performance, or to improve the performance of the rotating electric machine while maintaining the same size.

[0022] According to the rotating electric machine of the seventh invention, in any one of the first to sixth inventions, (a) the three-phase coil is Y-connected, (b) a first coil section and a second coil section are provided between the input terminal and the neutral point of the phase coil, each connected in parallel, and (c) the connection structure of the segment coils within the phase coil is the same for each phase. In this way, when the connection structure of the segment coils within each phase coil is the same, the complexity of the connection structure is avoided and it is made simpler compared to when it is not. For example, the bending and welding processes of the segment coils become a repeating pattern, improving the workability of the winding process of the three-phase coil.

[0023] According to the rotating electric machine of the 8th invention, in the 7th invention, the phase coils in the three-phase coil are such that, in the first coil section and the second coil section, the segment coils, which have the same connection order from the input terminal side of the phase coils, are inserted into circumferentially adjacent slots. By inserting segment coils, which have the same connection order from the input terminal side in the first coil section and the second coil section, into circumferentially adjacent slots, the connection structure of the first coil section and the second coil section becomes identical. In this way, when the connection structure of the first coil section and the second coil section is identical, the complexity of the connection structure is avoided and made simpler compared to when it is not. For example, the bending and welding processes of the segment coils become a repeating pattern, further improving the workability of the winding process of the three-phase coil.

[0024] According to the rotating electric machine of the ninth invention, in any one of the first to sixth inventions, (a) the three-phase coil is Y-connected, (b) one coil portion is provided between the input terminal and the neutral point of each of the phase coils, (c) each of the phase coils has two inner winding portions, two outer winding portions, and two connection portions, and (d) the connection structure of the segment coils in the phase coil is the same for each phase. With the configuration of the above (c), when the three-phase coil is Y-connected, the segment coils can be easily shared between a mode in which one phase coil is connected in series between the input terminal and the neutral point of each phase coil and a mode in which two phase coils are connected in parallel.

[0025] According to the rotating electric machine of the tenth invention, in the ninth invention, the phase coils in the three-phase coil are configured such that (a) in each of the two inner winding portions, the segment coils having the same connection order from the input terminal side are inserted into the slots adjacent in the circumferential direction, and (b) in each of the two outer winding portions, the segment coils having the same connection order from the input terminal side are inserted into the slots adjacent in the circumferential direction. In this way, by inserting the segment coils having the same connection order from the input terminal side in each of the two inner winding portions into the circumferentially adjacent slots, the two inner winding portions have the same connection structure as each other. By inserting the segment coils having the same connection order from the input terminal side in each of the two outer winding portions into the circumferentially adjacent slots, the two outer winding portions have the same connection structure as each other. As described above, when the two inner winding portions and the two outer winding portions have the same connection structure as each other, complication of the connection structure is avoided and the structure is simplified as compared with the case where they do not. For example, the bending process and welding process of the segment coils form a repeating pattern, and the workability of the winding process of the three-phase coil is improved. [Brief Description of the Drawings]

[0026] [Figure 1] This is a diagram illustrating an outline of a cross section of the rotating electric machine according to the present invention cut in the axial direction. [Figure 2] This figure illustrates the schematic method for winding a three-phase coil onto the stator core of a rotating electric machine according to Embodiment 1 of the present invention, where (a) is a perspective view of the stator core, (b) is a perspective view of a segment coil, (c) is a view of the stator core unfolded in the circumferential direction and viewed from the inner side to the outer side, showing a state in which one segment coil is inserted into a slot of the stator core, and (d) is a view of the stator core unfolded in the circumferential direction and viewed from the inner side to the outer side, showing a state in which a pair of arms of multiple segment coils are each inserted into a slot of the stator core, and one end of each pair of arms of segment coils inserted into different slots are welded together to connect them. [Figure 3] This is an electrically equivalent circuit diagram of a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 1 of the present invention. [Figure 4] Figure 3 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram showing the arrangement of the segment coils, (b) is a diagram illustrating the assignment of insertion positions of the segment coils in the first coil section and the second coil section of the U-phase coil, and (c) is a diagram illustrating the schematic of the connection structure of the U-phase coil. [Figure 5] Figure 4 illustrates the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the three-phase coil connection structure, and (b) is a diagram illustrating the details of the U-phase coil connection structure. [Figure 6] Figure 4 illustrates the types of segment coils used to construct the three-phase coil shown in the diagram. [Figure 7]Figure 5 illustrates the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, where (a) is a diagram illustrating the relationship between the voltage difference between adjacent segment coils and the connection order from the input terminal side of the segment coils, (b) is a diagram representing the voltage difference between adjacent segment coils, and (c) is a diagram representing the connection order from the input terminal side of the segment coils and the voltage difference between adjacent segment coils when segment coils of different phases are adjacent within the same slot. [Figure 8] Figure 5 illustrates the positional relationship of adjacent segment coils within a three-phase coil when segment coils of different phases are adjacent to each other within the same slot. [Figure 9] This diagram illustrates the connection structure of the segment coils constituting a three-phase coil according to Comparative Example 1, where (a) is an arrangement diagram of the segment coils, (b) is a diagram illustrating the general structure of the U-phase coil connection, and (c) is a diagram illustrating the types of segment coils used to constitute the three-phase coil. [Figure 10] Figure 9 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Figure 11] This is a diagram showing the arrangement of segment coils that constitute a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 2 of the present invention. [Figure 12] Figure 11 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil, (b) is a diagram illustrating the details of the connection structure of the U-phase coil, and (c) is a diagram illustrating the types of segment coils used to make up the three-phase coil. [Figure 13] Figure 12 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Figure 14] This is a diagram showing the arrangement of segment coils that constitute a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 3 of the present invention. [Figure 15] Figure 14 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil, (b) is a diagram illustrating the details of the connection structure of the U-phase coil, and (c) is a diagram illustrating the types of segment coils used to make up the three-phase coil. [Figure 16] Figure 15 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Figure 17] This is a diagram showing the arrangement of segment coils that constitute a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 4 of the present invention. [Figure 18] Figure 17 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil, (b) is a diagram illustrating the details of the connection structure of the U-phase coil, and (c) is a diagram illustrating the types of segment coils used to make up the three-phase coil. [Figure 19] Figure 18 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Figure 20] This is a diagram showing the arrangement of segment coils that constitute a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 5 of the present invention. [Figure 21] Figure 20 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil, and (b) is a diagram illustrating the types of segment coils used to make up the three-phase coil. [Figure 22]Figure 21 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Figure 23] This figure illustrates the connection structure of segment coils constituting a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 6 of the present invention, where (a) is a diagram illustrating the overall structure of the three-phase coil connection structure, and (b) is a diagram illustrating the types of segment coils used to constitute the three-phase coil. [Figure 24] This is an electrically equivalent circuit diagram of a three-phase coil wound around the stator core of a rotating electric machine according to Embodiment 7 of the present invention. [Figure 25] Figure 24 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram showing the arrangement of the segment coils, and (b) is a diagram illustrating the schematic of the connection structure of the U-phase coil. [Figure 26] Figure 25 is a diagram illustrating the connection structure of the segment coils that make up the three-phase coil, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil, (b) is a diagram illustrating the details of the connection structure of the U-phase coil, and (c) is a diagram illustrating the types of segment coils used to make up the three-phase coil. [Figure 27] Figure 26 illustrates the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, where (a) is a diagram illustrating the relationship between the voltage difference between adjacent segment coils and the connection order from the input terminal side of the segment coils, (b) is a diagram showing the voltage difference between adjacent segment coils, and (c) is a diagram showing the connection order from the input terminal side of each phase of the segment coils and the voltage difference between adjacent segment coils when segment coils of different phases are adjacent within the same slot. [Figure 28] Figure 26 illustrates the positional relationship of adjacent segment coils within a three-phase coil when segment coils of different phases are adjacent to each other within the same slot. [Figure 29] This diagram illustrates the connection structure of the segment coils constituting a three-phase coil according to Comparative Example 2, where (a) is an arrangement diagram of the segment coils, (b) is a diagram illustrating the connection structure of the U-phase coil, and (c) is a diagram illustrating the types of segment coils used to constitute the three-phase coil. [Figure 30] Figure 29 is a diagram illustrating the maximum voltage difference between adjacent segment coils within the same slot in a three-phase coil, and represents the voltage difference between adjacent segment coils. [Modes for carrying out the invention]

[0027] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. In each embodiment, the drawings have been simplified or modified as appropriate, and the dimensional ratios and shapes of each part are not necessarily depicted accurately. In this specification, "direction parallel to the axis CL," "radial direction centered on the axis CL," and "circumferential direction centered on the axis CL" will be simply referred to as "axis CL direction," "radial direction," and "circumferential direction," respectively. [Examples]

[0028] Figure 1 is a diagram illustrating a schematic cross-section of the rotating electric machine 10 according to the present invention, obtained by cutting it in the direction of the axis CL.

[0029] The rotating electric machine 10 is an electric motor that functions as a power source for driving, for example, mounted on a hybrid vehicle or an electric vehicle. The rotating electric machine 10 comprises a cylindrical stator core 22 formed by laminating multiple electromagnetic steel sheets and extending in the direction of the axis CL, and a rotor 30 provided on the inner circumference side of the stator core 22. The inner surface of the stator core 22 is provided with multiple grooves, i.e., multiple slots 22s (see Figure 2), which have a depth in the direction toward the outer circumference in the radial direction centered on the axis CL and penetrate in the direction of the axis CL. Teeth 22t (see Figure 2) are formed between adjacent slots 22s. A distributed winding three-phase coil 24 is wound around each slot 22s. The stator core 22 and the three-phase coil 24 constitute the stator 20. The rotor 30 is, for example, a well-known embedded magnet type, and the number of poles of the rotor 30 is predetermined. The number of poles of the rotor 30 is a multiple of 2, and in this embodiment, the number of poles of the rotor 30 is 4.

[0030] Figure 2 is a diagram illustrating the schematic method of winding a three-phase coil 24 onto a stator core 22 of a rotating electric machine 10 according to Embodiment 1 of the present invention, where (a) is a perspective view of the stator core 22, (b) is a perspective view of a segment coil 80, (c) is a view of the stator core 22 unfolded in the circumferential direction and viewed from the inner circumference to the outer circumference, showing a state in which one segment coil 80 is inserted into a slot 22s of the stator core 22, and (d) is a view of the stator core 22 unfolded in the circumferential direction and viewed from the inner circumference to the outer circumference, showing a state in which a pair of arms 82 of multiple segment coils 80 are each inserted into a slot 22s of the stator core 22, and one end of each pair of arms 82t of the segment coils 80 inserted into different slots 22s is welded together to connect them.

[0031] In this embodiment, the number of slots 22s is 24 (=4 × 6), which is 6 times the number of poles of the rotor 30. In Figure 2(a), the number of slots 22s is shown as 12.

[0032] As shown in Figure 2(b), the segment coil 80 is made of a so-called flat conductor with a rectangular cross-section, such as a longitudinal conductor plate, with an insulating coating such as enamel formed on its surface. The segment coil 80 is bent into a roughly U-shape. The segment coil 80 has a pair of arms 82 that extend linearly in the same direction on both sides of the U-shape, and a connecting part 84 that connects the bases of the pair of arms 82. The insulating coating has been removed from the tips 82t of the pair of arms 82.

[0033] First, as shown in Figure 2(c), a pair of arm portions 82 are inserted into the slot 22s from one end 22a of the stator core 22 towards the other end 22b. The one end 22a of the stator core 22 is one end of the stator core 22 in the axial direction CL, and the other end 22b of the stator core 22 is the other end of the stator core 22 in the axial direction CL. As a result, the connecting portion 84 is positioned on the one end 22a side. Also, the tip portions 82t of the pair of arm portions 82 protrude from the other end 22b.

[0034] Next, as shown in Figure 2(d), the tips 82t of each of the pair of arms 82 of the segment coil 80 are bent in the circumferential direction. Then, one of the tips 82t of the pair of arms 82 in one segment coil 80 is welded to the other of the pair of arms 82 in the other segment coil 80. That is, in the segment coils 80 inserted into each of the multiple slots 22s, the tips 82t of one of the pair of arms 82 of the segment coils 80 inserted into different slots 22s are welded together. In this way, the tips 82t of the multiple segment coils 80 are electrically connected by welding, forming a three-phase coil 24 wound around the teeth 22t. In the three-phase coil 24, the portion where the tips 82t of the multiple segment coils 80 are welded together is the welded portion 88. The welding is, for example, TIG (Tungsten Inert Gas) welding. Note that Figure 2 is a conceptual explanation; in reality, multiple segment coils 80 are inserted in a ring shape within the slot 22s, and these multiple segment coils 80 are welded to each other to form a three-phase coil 24. Six segment coils 80 are inserted into each of the multiple slots 22s.

[0035] Figure 3 is an electrically equivalent circuit diagram of a three-phase coil 24 wound around the stator core 22 of a rotating electric machine 10 according to Embodiment 1 of the present invention.

[0036] The three-phase coil 24 is Y-connected. The three-phase coil 24 consists of the U-phase coil 40, the V-phase coil 50, and the W-phase coil 60. The U-phase coil 40, the V-phase coil 50, and the W-phase coil 60 each correspond to the "phase coils" in this invention. The U-phase terminal 72 is an input terminal for inputting the U-phase of three-phase AC to the U-phase coil 40. The V-phase terminal 74 is an input terminal for inputting the V-phase of three-phase AC to the V-phase coil 50. The W-phase terminal 76 is an input terminal for inputting the W-phase of three-phase AC to the W-phase coil 60. Hereafter, unless otherwise specified, the U-phase coil 40, the V-phase coil 50, and the W-phase coil 60 will simply be referred to as "phase coils". Unless otherwise specified, the U-phase terminal 72, the V-phase terminal 74, and the W-phase terminal 76 will be referred to as "input terminals 70". The U-phase terminal 72, the V-phase terminal 74, and the W-phase terminal 76 correspond to the "input terminals" in this invention. The U-phase coil 40 has one end connected to the U-phase terminal 72 and the other end connected to the neutral point N. The V-phase coil 50 has one end connected to the V-phase terminal 74 and the other end connected to the neutral point N. The W-phase coil 60 has one end connected to the W-phase terminal 76 and the other end connected to the neutral point N. The U-phase coil 40 comprises two parallel-connected first coil sections 42 and second coil sections 44 between the U-phase terminal 72 and the neutral point N. The V-phase coil 50 comprises two parallel-connected first coil sections 52 and second coil sections 54 between the V-phase terminal 74 and the neutral point N. The W-phase coil 60 comprises two parallel-connected first coil sections 62 and second coil sections 64 between the W-phase terminal 76 and the neutral point N. Thus, each of the phase coils of the three-phase coil 24 has one end connected to the input terminal 70 of its respective phase and the other end connected to the neutral point N, and comprises two parallel-connected first coil sections and second coil sections between the input terminal 70 of each phase and the neutral point N.

[0037] Here, the positions in which the segment coil 80 in the first coil section 42 of the U-phase coil 40 is inserted into the slot 22s will be denoted as insertion positions U1a, U2a, U3a, U4a, ..., U23a, U24a, in order from the U-phase terminal 72 side toward the neutral point N. The positions in which the segment coil 80 in the second coil section 44 of the U-phase coil 40 is inserted into the slot 22s will be denoted as insertion positions U1b, U2b, U3b, U4b, ..., U23b, U24b, in order from the U-phase terminal 72 side toward the neutral point N. The positions in which the segment coil 80 in the first coil section 52 of the V-phase coil 50 is inserted into the slot 22s will be denoted as insertion positions V1a, V2a, V3a, V4a, ..., V23a, V24a, in order from the V-phase terminal 74 side toward the neutral point N. The positions in which the segment coil 80 in the second coil section 54 of the V-phase coil 50 is inserted into the slot 22s will be denoted as insertion positions V1b, V2b, V3b, V4b, ..., V23b, V24b, in order from the V-phase terminal 74 side toward the neutral point N. The positions in which the segment coil 80 in the first coil section 62 of the W-phase coil 60 is inserted into the slot 22s will be denoted as insertion positions W1a, W2a, W3a, W4a, ..., W23a, W24a, in order from the W-phase terminal 76 side toward the neutral point N. The positions in which the segment coil 80 in the second coil section 64 of the W-phase coil 60 is inserted into the slot 22s will be denoted as insertion positions W1b, W2b, W3b, W4b, ..., W23b, W24b, in order from the W-phase terminal 76 side toward the neutral point N. In these insertion position notations, the leading letters U, V, and W indicate the segment coils 80 that make up the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. The numerical part indicates the connection order from the input terminal 70 side of each phase toward the neutral point N. The trailing letters a and b indicate that "a" is the first coil section and "b" is the second coil section.

[0038] Figure 4 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 24 shown in Figure 3, where (a) is an arrangement diagram of the segment coils 80, (b) is an explanatory diagram of the assignment of insertion positions of the segment coils 80 in the first coil section 42 and the second coil section 44 of the U-phase coil 40, and (c) is a diagram illustrating the outline of the connection structure of the U-phase coil 40. Figure 5 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 24 shown in Figure 4, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 24, and (b) is a diagram illustrating the details of the connection structure of the U-phase coil 40. "Connection structure" refers to the physical arrangement structure of the multiple segment coils 80 that constitute the three-phase coil 24. Specifically, "connection structure" refers to the relative positional relationship of the insertion positions of each segment coil 80 and the connection relationship between the tip portions 82t within a coil in which multiple segment coils 80 are connected.

[0039] The slot numbers S1 to S24 shown in Figure 4 represent the sequentially assigned numbers in the circumferential direction for each of the 24 slots 22s, i.e., the circumferential positions. The insertion positions of the segment coils 80 in the radial direction are designated as the 1st layer, 2nd layer, 3rd layer, 4th layer, 5th layer, and 6th layer, starting from the outer circumference and moving towards the inner circumference. Six segment coils 80 are inserted into each of the 24 slots 22s. As shown in Figure 4(a), in the three-phase coil 24, three segment coils 80 of the same phase are inserted into the outer circumference of one pair of circumferentially adjacent slots 22s from the 1st to 3rd layers, and three segment coils each are inserted into the inner circumference of another pair of slots 22s that are shifted by one slot 22s in the circumferential direction relative to the first pair of slots 22s, from the 4th to 6th layers. In Figure 4(a), the insertion positions of the in-phase segment coils 80, i.e., one set of slots 22s and another set of slots 22s, are shown enclosed by thick solid lines. Hereafter, each region enclosed by these thick solid lines will be referred to as an "in-phase insertion unit". The insertion positions of the segment coils 80 constituting the three-phase coil 24 are represented by specifying the slot numbers S1 to S24 and the layers 1 to 6, which represent the radial position. For example, the insertion positions U1a, U2a, U3a, U4a, ..., U23a, U24a in the first coil section 42 of the U-phase coil 40 are represented by specifying one of the slot numbers S1 to S24, which represent the circumferential position, and one of the layers 1 to 6, which represent the radial position.

[0040] In the circumferential direction, a V-phase in-phase insertion unit is positioned adjacent to a U-phase in-phase insertion unit. In the circumferential direction, a W-phase in-phase insertion unit is positioned adjacent to that V-phase in-phase insertion unit. In the circumferential direction, a U-phase in-phase insertion unit is positioned adjacent to that W-phase in-phase insertion unit. In this way, in the circumferential direction, U-phase, V-phase, and W-phase in-phase insertion units are repeatedly positioned adjacent to each other.

[0041] In the in-phase insertion units of each of the U, V, and W phases, the insertion positions of the segment coils 80 in the first coil section and the second coil section are assigned, respectively. These assignments are the same for each phase in the in-phase insertion units. Therefore, in the following, we will explain the assignments of the insertion positions of the segment coils 80 in the first coil section 42 and the second coil section 44 in the in-phase insertion unit of the U-phase coil 40 as a representative example, and omit explanations for the other phases.

[0042] In Figure 4(b), the insertion positions of the segment coils 80 for the V-phase coil 50 and W-phase coil 60 are omitted from Figure 4(a), and only the insertion position of the segment coil 80 for the U-phase coil 40 is shown. Furthermore, to make it easier to distinguish between the insertion positions of the segment coils 80 for the first coil section 42 and the second coil section 44, the insertion positions of the segment coils 80 for the second coil section 44 are shown in inverted black and white characters. As shown in Figure 4(b), within each in-phase insertion unit, in each of the 1st to 6th layers, the insertion positions of the segment coils 80 for the first coil section 42 and the insertion positions of the segment coils 80 for the second coil section 44 are adjacent in the circumferential direction. In each in-phase insertion unit, for the slot 22s into which only the segment coil 80 of the U-phase coil 40 is inserted, one of the insertion positions for the segment coil 80 of the first coil section 42 and the insertion positions for the segment coil 80 of the second coil section 44 is set to the 1st, 3rd, 4th, and 6th layers, while the other is set to the 2nd and 5th layers. In two in-phase insertion units adjacent to each other in the circumferential direction, the insertion positions for the segment coil 80 of the first coil section 42 and the insertion positions for the segment coil 80 of the second coil section 44 are opposite each other in the circumferential direction in each of the 1st to 6th layers.

[0043] As shown in Figures 4 and 5, the V-phase coil 50 is obtained by shifting the connection structure of the segment coil 80 constituting the U-phase coil 40 to the left by 4 slots 22s in the circumferential direction, and the connection structure itself is the same. The W-phase coil 60 is obtained by shifting the connection structure of the segment coil 80 constituting the U-phase coil 40 to the left by 8 slots 22s in the circumferential direction, and the connection structure itself is the same. In addition, in the first coil section 42 and the second coil section 44 of the U-phase coil 40, segment coils 80 with the same connection order from the U-phase terminal 72 side are inserted into circumferentially adjacent slots 22s. Therefore, in the following, the connection structure of the segment coil 80 constituting the first coil section 42 will be described as a representative example, and explanations of other connection structures will be omitted as appropriate. Note that "number of slots 22s pitch" (hereinafter simply referred to as "number of pitches") represents the spacing in the circumferential direction, and indicates how many times the spacing between circumferentially adjacent slots 22s is.

[0044] In Figure 4(c), the dashed line represents the connecting portion 84 side of the segment coil 80, and the solid line represents the tip portion 82t side, i.e., the welded portion 88 side. The same applies to Figure 5. For example, in the first coil section 42, a pair of arm portions 82 of the segment coil 80 are inserted into the first layer of slot number S1 and the first layer of slot number S8, respectively, and a pair of arm portions 82 of the segment coil 80 are inserted into the second layer of slot number S14 and the first layer of slot number S20, respectively. A U-phase terminal 72 is connected to the tip portion 82t inserted into the first layer of slot number S1, and the tip portion 82t inserted into the first layer of slot number S8 and the tip portion 82t inserted into the second layer of slot number S14 are electrically connected by welding.

[0045] As shown in Figures 4(c) and 5(b), the first coil section 42 has an outer circumference end connection section Jo1, an inner winding section 42a, an outer winding section 42b, and an inner circumference end connection section Ji1 that connects the inner circumference end of the inner winding section 42a to the inner circumference end of the outer winding section 42b. The inner winding section 42a is the portion to which the segment coil 80 is connected from the outer circumference side connected to the U-phase terminal 72 toward the inner circumference side. The outer winding section 42b is the portion to which the segment coil 80 is connected from the inner circumference side toward the outer circumference side connected to the neutral point N. In the inner winding section 42a, "from the outer circumference to the inner circumference" means that the connection of the segment coil 80 as a whole starts from the first layer and ends at the sixth layer, and does not exclude connections from the second layer to the first layer, from the fourth layer to the third layer, or from the sixth layer to the fifth layer, as described later in the outer layer connection section Ro, the intermediate layer connection section Rm, and the inner layer connection section Ri. In the outer winding section 42b, "from the inner circumference to the outer circumference" means that the connection of the segment coil 80 as a whole starts from the sixth layer and ends at the first or second layer, and does not exclude connections from the first layer to the second layer, from the third layer to the fourth layer, or from the fifth layer to the sixth layer, as described later in the outer layer connection section Ro, the intermediate layer connection section Rm, and the inner layer connection section Ri.

[0046] The inner winding portion 42a and the outer winding portion 42b each have an outer circumferential layer connection portion Ro, an outer circumferential layer transfer portion SWo, an intermediate layer connection portion Rm, an inner circumferential layer transfer portion SWi, and an inner circumferential layer connection portion Ri, respectively. The outer circumferential layer connection portion Ro is a portion where segment coils 80 are alternately inserted at the positions of the 1st and 2nd layers and connected in a circumferential direction. The intermediate layer connection portion Rm is a portion where segment coils 80 are alternately inserted at the positions of the 3rd and 4th layers and connected in a circumferential direction. The inner circumferential layer connection portion Ri is a portion where segment coils 80 are alternately inserted at the positions of the 5th and 6th layers and connected in a circumferential direction. The outer circumferential layer transfer portion SWo is a portion that connects the 2nd layer, which is the end of the outer circumferential layer connection portion Ro, and the 3rd layer, which is the end of the intermediate layer connection portion Rm. The inner circumferential layer transfer portion SWi is a portion that connects the 5th layer, which is the end of the inner circumferential layer connection portion Ri, and the 4th layer, which is the end of the intermediate layer connection portion Rm. In the outer layer connection section Ro, one end is connected to the U-phase terminal 72, and the other end is connected to the intermediate layer connection section Rm via the outer layer side transfer section SWo. In the inner layer connection section Ri, one end is connected to the inner end connection section Ji1, and the other end is connected to the intermediate layer connection section Rm via the inner layer side transfer section SWi.

[0047] The inward winding start position A1 is the insertion position of one of the segments 80 at the outer circumferential layer connection Ro of the inward winding section 42a, where the segment coil 80 is initially connected from one of the first and second layers to the other. The inward winding start position A1 corresponds to the "winding start position" in the present invention. Specifically, in the drawing, the inward winding start position A1 is the first layer of slot number S8, which is shifted 7 pitches to the left from slot number S1, to which the U-phase terminal 72 is connected by the outer circumferential end connection Jo1. The inward winding end position A2 is the insertion position of the sixth layer at the inner circumferential layer connection Ri of the inward winding section 42a, where the segment coil 80 is last connected from the fifth layer to the sixth layer. The outward winding start position A3 is the insertion position of the sixth layer at the inner circumferential layer connection Ri of the outward winding section 42b, where the segment coil 80 is initially connected from the sixth layer to the fifth layer. The inner winding end position A2 corresponds to the "end on the inner circumference side of the inner winding portion" in this invention. The outer winding start position A3 corresponds to the "end on the inner circumference side of the outer winding portion" in this invention. The outer winding end position A4 is the other insertion position at the outer peripheral layer connection portion Ro of the outer winding portion 42b where the segment coil 80 is last connected from one of the first and second layers to the other.

[0048] The outer circumference end connection portion Jo1 is the portion where the segment coil 80 is positioned between the U-phase terminal 72 and the inward winding start position A1, and is the portion that connects the first layers of the segment coils 80 that are inserted into each other. Specifically, it is the portion that connects the first layer of slot number S1 and the first layer of slot number S8. The inner circumference end connection portion Ji1 is the portion where the segment coil 80 is positioned between the inward winding end position A2 and the outward winding start position A3.

[0049] The outer circumference end connection portion Jo2, inner winding portion 44a, outer winding portion 44b, and inner circumference end connection portion Ji2 of the second coil portion 44 have the same configuration as the outer circumference end connection portion Jo1, inner winding portion 42a, outer winding portion 42b, and inner circumference end connection portion Ji1 of the first coil portion 42.

[0050] The inward winding start position B1 is the insertion position of one of the segments 80 at the outer circumferential layer connection Ro of the inward winding section 44a, where the segment coil 80 is initially connected from one of the first or second layers to the other. The inward winding start position B1 corresponds to the "winding start position" in the present invention. Specifically, in the drawing, the inward winding start position B1 is the first layer of slot number S7, which is shifted 5 pitches to the left from slot number S2, to which the U-phase terminal 72 is connected by the outer circumferential end connection Jo2. The inward winding end position B2 is the insertion position of the sixth layer at the inner circumferential layer connection Ri of the inward winding section 44a, where the segment coil 80 is last connected from the fifth layer to the sixth layer. The outward winding start position B3 is the insertion position of the sixth layer at the inner circumferential layer connection Ri of the outward winding section 44b, where the segment coil 80 is initially connected from the sixth layer to the fifth layer. The inner winding end position B2 corresponds to the "inner circumference end of the inner winding portion" in this invention. The outer winding start position B3 corresponds to the "inner circumference end of the outer winding portion" in this invention. The outer winding end position B4 is the insertion position of the other end of the outer outer layer connection portion Ro of the outer winding portion 44b, where the segment coil 80 is last connected from one of the 5th and 6th layers to the other. The inner circumference end connection portion Ji2 is the portion where the segment coil 80 is positioned between the inner winding end position B2 and the outer winding start position B3.

[0051] The outer circumference end connection portion Jo1, the inner winding portion 52a, the outer winding portion 52b, and the inner circumference end connection portion Ji1 connecting their inner ends in the first coil portion 52 correspond to the outer circumference end connection portion Jo1, the inner winding portion 42a, the outer winding portion 42b, and the inner circumference end connection portion Ji1 connecting their inner ends in the first coil portion 42, respectively. The outer circumference end connection portion Jo2, the inner winding portion 54a, the outer winding portion 54b, and the inner circumference end connection portion Ji2 connecting their inner ends in the second coil portion 54 correspond to the outer circumference end connection portion Jo2, the inner winding portion 44a, the outer winding portion 44b, and the inner circumference end connection portion Ji2 connecting their inner ends in the second coil portion 44, respectively. The outer circumference end connection portion Jo1, the inner winding portion 62a, the outer winding portion 62b, and the inner circumference end connection portion Ji1 connecting their inner ends in the first coil portion 62 correspond to the outer circumference end connection portion Jo1, the inner winding portion 42a, the outer winding portion 42b, and the inner circumference end connection portion Ji1 connecting their inner ends in the first coil portion 42, respectively. The outer circumference end connection portion Jo2, the inner winding portion 64a, the outer winding portion 64b, and the inner circumference end connection portion Ji2 connecting their inner ends in the second coil portion 64 correspond to the outer circumference end connection portion Jo2, the inner winding portion 44a, the outer winding portion 44b, and the inner circumference end connection portion Ji2 connecting their inner ends in the second coil portion 44, respectively.

[0052] The direction in which the segment coil 80 in the inner winding section 42a rotates in the circumferential direction is opposite to the direction in which the segment coil 80 in the outer winding section 42b rotates in the circumferential direction. Specifically, as shown in Figures 4 and 5, in the drawings, the outer peripheral layer connection part Ro in the inner winding section 42a rotates counterclockwise from slot numbers S8 (U2a) → S14 (U3a) → S20 (U4a) → S2 (U5a), and the outer peripheral layer connection part Ro in the outer winding section 42b rotates clockwise from slot numbers S19 (U22a) → S13 (U23a) → S7 (U24a). Similarly, in the drawings, the intermediate layer connection part Rm in the inner winding section 42a rotates counterclockwise, and the intermediate layer connection part Rm in the outer winding section 42b rotates clockwise. In the drawing, the inner circumferential layer connection Ri in the inner winding section 42a rotates to the left, while the inner circumferential layer connection Ri in the outer winding section 42b rotates to the right. The inner winding section 42a and the outer winding section 42b have a double helix connection structure at the outer circumferential layer connection Ro, the intermediate layer connection Rm, and the inner circumferential layer connection Ri, respectively. "Double helix" refers to a state in which the two wires to which the segment coil 80 is connected form a parallel helix.

[0053] Regarding the connection sequence of the segment coils 80 from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the third layer is made after the connection to the outer layer connection part Ro of the inner winding portion 42a. That is, when viewed from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the third layer is made after the outer layer connection part Ro of the inner winding portion 42a has rotated in the circumferential direction, or after the outer layer connection part Ro of the inner winding portion 42a has rotated in the circumferential direction and further after the inner circumferential layer connection part Ri of the outer winding portion 42b has rotated in the circumferential direction. Regarding the connection sequence of the segment coils 80 from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the fourth layer is made after the connection to the outer layer connection part Ro of the inner winding portion 42a. In other words, the connection to the segment coil 80 inserted in the fourth layer when viewed from the U-phase terminal 72 side is made after the outer circumferential layer connection part Ro of the inner winding part 42a has rotated circumferentially, or after the outer circumferential layer connection part Ro of the inner winding part 42a has rotated circumferentially and further after the inner circumferential layer connection part Ri of the outer winding part 42b has rotated circumferentially. Thus, the connection to the segment coil 80 inserted in the third layer and the connection to the segment coil 80 inserted in the fourth layer when viewed from the U-phase terminal 72 side are both made after the outer circumferential layer connection part Ro of the inner winding part 42a has rotated circumferentially.

[0054] Figure 6 is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 24 shown in Figure 4.

[0055] At the outer layer connection Ro and the inner layer connection Ri, the pitch count of the segment coil 80 on the connecting portion 84 side (dashed line side shown in Figures 4 and 5) and the welded portion 88 side (solid line side shown in Figures 4 and 5) is 6. At the intermediate layer connection Rm, the pitch count of the segment coil 80 on the connecting portion 84 side and the welded portion 88 side is 5 and 7 on the connecting portion 84 side. At the outer layer transfer portion SWo and the inner layer transfer portion SWi, the pitch count of the segment coil 80 on the connecting portion 84 side is 6. For segment coils 80 in which both of a pair of arm portions 82 are inserted into the first layer and segment coils 80 in which both of a pair of arm portions 82 are inserted into the sixth layer, the pitch count of the segment coil 80 on the connecting portion 84 side is both 5 and 7.

[0056] Figure 7 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 24 shown in Figure 5, where (a) is a diagram illustrating the relationship between the voltage difference between adjacent segment coils 80 and the connection order from the input terminal 70 side of the segment coils 80, (b) is a diagram showing the voltage difference between adjacent segment coils 80, and (c) is a diagram showing the connection order from the input terminal 70 side of the segment coils 80 and the voltage difference between adjacent segment coils 80 when segment coils 80 of different phases are adjacent within the same slot 22s.

[0057] As shown in Figure 7(a), adjacent segment coils 80 within the same slot 22s are arranged alternately in the circumferential direction between slots 22s in which six segment coils 80 of the same phase are inserted, and slots 22s in which three segment coils 80 of different phases are inserted. In Figure 7(a), the insertion positions where segment coils 80 of different phases are adjacent within the same slot 22s are indicated by inverted black and white characters.

[0058] From here, using Figure 3, we will explain the voltage difference between adjacent segment coils 80 within the same slot 22s. When the rotating electric machine 10 is driven to rotate, a three-phase AC voltage is applied to the U-phase terminal 72, the V-phase terminal 74, and the W-phase terminal 76, respectively. The voltage difference between adjacent segment coils 80 within the same slot 22s can be calculated in the following cases: between U-phase coil 40 segment coils 80, between V-phase coil 50 segment coils 80, between W-phase coil 60 segment coils 80, between U-phase coil 40 segment coil 80 and V-phase coil 50 segment coil 80, between V-phase coil 50 segment coil 80 and W-phase coil 60 segment coil 80, and between W-phase coil 60 segment coil 80 and U-phase coil 40 segment coil 80. The voltage difference can be calculated using different methods for the case between segment coils 80 of the same phase and between segment coils 80 of different phases. Therefore, we will explain, as representative examples, the case between the segment coils 80 of the U-phase coil 40 and the case between the segment coil 80 of the U-phase coil 40 and the segment coil 80 of the V-phase coil 50.

[0059] In the following explanation, for the sake of ease of understanding, we will simplify the description by assuming that the segment coil 80 wound around the stator core 22, which is made of electromagnetic steel sheet, functions as an ideal inductive reactance. That is, the resistive and capacitive reactance components of the segment coil 80 are both sufficiently small compared to the inductive reactance component and can be ignored. Furthermore, when multiple segment coils 80 are connected, the inductive reactance components at the connection portion 84 and the welded portion 88 of the segment coil 80 are assumed to be the same. Here, the impedance, which is the inductive reactance between the U-phase terminal 72 and the V-phase terminal 74, is denoted as impedance Z1 [Ω].

[0060] Between the U-phase terminal 72 and the neutral point N, there are a total of 23 locations, alternating between the locations on the connecting portion 84 side of the segment coil 80 and the locations on the welded portion 88 side where the tip portions 82t are welded together. There are 12 locations on the connecting portion 84 side and 11 locations on the welded portion 88 side. The same applies between the V-phase terminal 74 and the neutral point N.

[0061] For example, when a voltage Vo [V] is applied to the U-phase terminal 72 relative to the V-phase terminal 74, a current Io (=Vo / Z1) [A] flows between the U-phase terminal 72 and the V-phase terminal 74. In this case, (1 / 46 × Vo) [V] is applied to the connection portion 84 and the welded portion 88 of the segment coil 80, respectively, between the U-phase terminal 72 and the V-phase terminal 74. In the U-phase coil 40, the potential decreases by (1 / 46 × Vo) [V] for each increase in the connection sequence from the U-phase terminal 72 towards the neutral point N. In the V-phase coil 50, the potential increases by (1 / 46 × Vo) [V] for each increase in the connection sequence from the V-phase terminal 74 towards the neutral point N.

[0062] First, we will explain the case where adjacent segment coils 80 within the same slot 22s are in phase, for example, when one segment coil 80 has its U-phase coil 40 inserted at connection order Nu1 and another segment coil 80 has its U-phase coil 40 inserted at connection order Nu2 are adjacent. Connection orders Nu1 and Nu2 correspond to the numerical part of the insertion position (U1a~U24a, U1b~U24b). In this case, the voltage difference between adjacent segment coils 80 is the difference in connection order (=|Nu1-Nu2|) from the U-phase terminal 72 side, which is a common input terminal of adjacent segment coils 80, toward the neutral point N, multiplied by (1 / 46×Vo)[V]. Note that the maximum value of the difference in connection order from the common input terminal 70 side toward the neutral point N of adjacent segment coils 80 is "23", which is the difference between the maximum value (=24) and the minimum value (=1) of the connection order.

[0063] Next, we will describe the case where adjacent segment coils 80 within the same slot 22s are of different phases, for example, when one segment coil 80 of the U-phase coil 40 has an insertion position in connection order Nu3, and another segment coil 80 of the V-phase coil 50 has an insertion position in connection order Nv3, and these are adjacent. Connection order Nu3 is equivalent to the numerical part of the insertion position (U1a~U24a, U1b~U24b), and connection order Nv3 is equivalent to the numerical part of the insertion position (V1a~V24a, V1b~V24b). In this case, the total number of connection portions 84 and welded portions 88 of the segment coil 80 provided between the insertion position of one segment coil 80 and the insertion position of the other segment coil 80 is denoted as total T. The total number of connection portions 84 and welded portions 88 of the segment coil 80 connected in series between the insertion position of one segment coil 80 of the U-phase coil 40 and the neutral point N is denoted as number Xu. Let Xv be the total number of locations on the connection part 84 side and the welded part 88 side of the segment coil 80 connected in series between the insertion position of the other segment coil 80 of the V-phase coil 50 and the neutral point N. Number Xu is the same as the difference {=23-(Nu3-1)} between the sum of the locations on the connection part 84 side and the welded part 88 side of the segment coil 80 connected in series between the U-phase terminal 72 and the neutral point N (="23") and the number obtained by subtracting "1" from the connection order Nu3 of the insertion position of one segment coil 80. Number Xv is the same as the difference {=23-(Nv3-1)} between the sum of the locations on the connection part 84 side and the welded part 88 side of the segment coil 80 connected in series between the V-phase terminal 74 and the neutral point N (="23") and the number obtained by subtracting "1" from the connection order Nv3 of the insertion position of the other segment coil 80. The total T is the sum of the numbers Xu and Xv (=Xu+Xv). Therefore, the total T is the difference between "48" and the sum of the connection order Nu3 and the connection order Nv3 {=48-(Nu3+Nv3)}. When one segment coil 80 of the U-phase coil 40 and another segment coil 80 of the V-phase coil 50 are adjacent within the same slot 22s, the voltage obtained by multiplying the total T by (1 / 46×Vo)[V] becomes the voltage difference between the adjacent segment coils 80.The voltage difference can be calculated using the same method when the segment coil 80 of the V-phase coil 50 and the segment coil 80 of the W-phase coil 60 are adjacent within the same slot 22s, and also when the segment coil 80 of the W-phase coil 60 and the segment coil 80 of the U-phase coil 40 are adjacent within the same slot 22s.

[0064] Returning to Figure 7, for example, segment coils 80 inserted at insertion positions U23b and U3a are adjacent within the same slot 22s. The voltage difference between adjacent segment coils 80 is the difference 20 (=23-3) in the connection order from the common U-phase terminal 72 towards the neutral point N, multiplied by (1 / 46 × Vo) [V] (=20 / 46 × Vo). For example, if two segment coils 80 inserted at insertion positions V6a and U7b are adjacent within the same slot 22s, the voltage difference between the adjacent segment coils 80 is calculated by multiplying the number obtained by subtracting from "48" the sum of "the connection sequence from the U-phase terminal 72 side of the segment coil 80 inserted at insertion position U7b toward the neutral point N (=7) and the connection sequence from the V-phase terminal 74 side of the segment coil 80 inserted at insertion position V6a toward the neutral point N (=6) (=13)" (=35) by (1 / 46 × Vo) [V].

[0065] Figure 7(b) shows the voltage difference between adjacent segment coils 80 within the same slot 22s, and the value is obtained by dividing each voltage difference by (1 / 46 × Vo) [V]. The larger the number shown in Figure 7(b), the greater the voltage difference between adjacent segment coils 80. The voltage difference between the segment coil 80 inserted in the 3rd layer and the segment coil 80 inserted in the 4th layer of slot number S12, and the voltage difference between the segment coil 80 inserted in the 3rd layer and the segment coil 80 inserted in the 4th layer of slot number S16, both have the maximum voltage difference (=35 / 46 × Vo). In Figure 7(b), the locations where the voltage difference between adjacent segment coils 80 is at its maximum are indicated by inverted black and white text. As mentioned above, when in-phase segment coils 80 are adjacent within the same slot 22s, the maximum value obtained by dividing the voltage difference between adjacent segment coils 80 by (1 / 46 × Vo) [V] is "23".

[0066] Figure 7(c) shows the connection order from the input terminal 70 side of each phase of the segment coil 80 and the voltage difference between adjacent segment coils 80 when segment coils 80 of different phases are adjacent to each other in the same slot 22s.

[0067] Figure 8 illustrates the positional relationship of adjacent segment coils 80 within the three-phase coil 24 when segment coils 80 of different phases are adjacent within the same slot 22s in the three-phase coil 24 shown in Figure 5.

[0068] As shown in Figure 8, two coil sections, a first coil section 42 and a second coil section 44, are connected in parallel between the U-phase terminal 72 and the neutral point N. The first coil section 42 has the outer circumference end connection Jo1, the inner winding section 42a, the inner circumference end connection Ji1, and the outer winding section 42b connected in series, in that order from the U-phase terminal 72 towards the neutral point N. The second coil section 44 has the outer circumference end connection Jo2, the inner winding section 44a, the inner circumference end connection Ji2, and the outer winding section 44b connected in series, in that order from the U-phase terminal 72 towards the neutral point N. If the inner winding sections 42a and 44a are considered the forward path from the outer circumference to the inner circumference, then the outer winding sections 42b and 44b are considered the return path from the inner circumference to the outer circumference. Two coil sections, a first coil section 52 and a second coil section 54, are connected in parallel between the V-phase terminal 74 and the neutral point N with a similar connection structure. Between the W-phase terminal 76 and the neutral point N, two coil sections, a first coil section 62 and a second coil section 64, are connected in parallel using a similar connection structure.

[0069] When segment coils 80 of different phases are adjacent within the same slot 22s, these adjacent segment coils 80 are a combination of a segment coil 80 inserted in the third layer and a segment coil 80 inserted in the fourth layer. Regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the third layer is made after the outer layer connection part Ro in the inner winding portion of each phase coil. That is, the segment coil 80 inserted in the third layer is connected after the outer layer connection part Ro in the inner winding portion of each phase coil has gone around in the circumferential direction when viewed from the input terminal 70 side of each phase. Regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the fourth layer is made after the outer layer connection part Ro in the inner winding portion of each phase coil. That is, the segment coil 80 inserted in the fourth layer is connected after the outer layer connection part Ro in the inner winding portion of each phase coil has gone around in the circumferential direction when viewed from the input terminal 70 side of each phase. In Figure 8, when segment coils 80 of different phases are adjacent to each other within the same slot 22s, the relative positions of these adjacent segment coils 80 are indicated by dashed arrows.

[0070] Figure 9 illustrates the connection structure of the segment coils 80 constituting the three-phase coil 824 according to Comparative Example 1, where (a) is an arrangement diagram of the segment coils 80, (b) is a diagram illustrating the schematic of the connection structure of the U-phase coil 840, and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 824. The three-phase coil 824 has substantially the same configuration as the three-phase coil 24 according to the above-described Example 1, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 840, V-phase coil 850, and W-phase coil 860, respectively. In this comparative example, the explanation will focus on the parts that differ from Example 1, and parts that are substantially common in function with Example 1 will be given the same reference numerals and their explanations will be omitted as appropriate.

[0071] As shown in Figure 9(a), in the three-phase coil 824, six in-phase segment coils 80 are inserted from the first to the sixth layer of one of the 24 slots 22s (in this comparative example, slots 22s with odd-numbered slot numbers), and six more are inserted in the first, third, and fifth layers of one of the two adjacent slots 22s in the circumferential direction of that slot 22s, and in the second, fourth, and sixth layers of the other slot 22s. In Figure 9(a), each insertion area where the in-phase segment coils 80 are inserted is shown enclosed by a thick solid line.

[0072] As shown in Figure 9(a), the V-phase coil 850 is the same as the U-phase coil 840, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 860 is the same as the U-phase coil 840, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. Therefore, in the following, we will describe the connection structure of the segment coil 80 constituting the first coil section 842 and the second coil section 844 of the U-phase coil 840 as a representative example, and will omit explanations of other connection structures as appropriate.

[0073] As shown in Figure 9(b), the first coil section 842 has a portion on the connecting section 84 side of the segment coil 80 where the tip portions 82t of a segment coil 80 in which both of a pair of arm portions 82 are inserted into the first layer, a segment coil 80 in which both of a pair of arm portions 82 are inserted into the second and third layers, and a segment coil 80 in which both of a pair of arm portions 82 are inserted into the fourth and fifth layers are sequentially connected, and the connections proceed in a zigzag pattern from the outer circumference to the inner circumference. The first coil section 842 has a portion on the connecting section 84 side of the segment coil 80 where the tip portions 82t of a segment coil 80 in which both of a pair of arm portions 82 are inserted into the sixth layer, a segment coil 80 in which both of a pair of arm portions 82 are inserted into the fifth and fourth layers, and a segment coil 80 in which both of a pair of arm portions 82 are inserted into the third and second layers are sequentially connected, and the connections proceed in a zigzag pattern from the inner circumference to the outer circumference. Thus, the first coil section 842 has a structure in which a portion connected in a zigzag pattern from the outer circumference to the inner circumference and a portion connected in a zigzag pattern from the inner circumference to the outer circumference are connected, and this structure is repeated in the circumferential direction as a single unit. The second coil section 844 has a similar configuration.

[0074] As shown in Figure 9(c), on the welded portion 88 side (solid line side shown in Figure 9(b)) of the segment coil 80, the number of pitches of the segment coils 80 inserted into the 6th layers is 7, and the number of pitches of the remaining segment coils 80 is 5 on both the welded portion 88 side (solid line side shown in Figure 9(b)) and the connecting portion 84 side (dashed line side shown in Figure 9(b)). There are two types of segment coils 80 used to construct the three-phase coil 824.

[0075] Figure 10 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 824 shown in Figure 9, and represents the voltage difference between adjacent segment coils 80. The values ​​shown in Figure 10 are obtained by dividing the voltage difference between each adjacent segment coil 80 within the same slot 22s by (1 / 46 × Vo) [V].

[0076] As shown in Figure 10, the voltage difference between the segment coil 80 inserted in the second layer and the segment coil 80 inserted in the third layer of slot number S10, and the voltage difference between the segment coil 80 inserted in the second layer and the segment coil 80 inserted in the third layer of slot number S6, are both at their maximum values ​​(=45 / 46 × Vo). In Figure 10, locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated with inverted black and white text. In this embodiment, compared to Comparative Example 1, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by approximately 22.2[%]{=1-(35 / 45)}.

[0077] In this embodiment, (a) the number of slots 22s is 24, which is 6 times the number of poles of the rotor 30, and (b) when the insertion positions of the segment coils 80, which are inserted in 6 of each of the 24 slots 22s, are designated as the 1st layer, 2nd layer, 3rd layer, 4th layer, 5th layer, and 6th layer from the outer circumference to the inner circumference, the segment coils 80 of the same phase in the three-phase coil 24 are inserted in 3 from the 1st to 3rd layers on the outer circumference side of one set of circumferentially adjacent slots 22s out of the 24 slots 22s, and inserted in 3 from the 4th to 6th layers on the inner circumference side of another set of slots 22s which are shifted by one slot 22s in the circumferential direction relative to the set of slots 22s, and (c) the phase coils of each phase in the three-phase coil 24 are inserted from the outer circumference side (d) The coil has an inner winding section (e.g., inner winding section 42a) to which the segment coil 80 is connected toward the inner circumference, an outer winding section (e.g., outer winding section 42b) to which the segment coil 80 is connected from the inner circumference toward the outer circumference, and an inner circumference end connection section (e.g., inner circumference end connection section Ji1) that connects the inner circumference ends of the inner and outer winding sections, respectively, and (e) the connection sequence of the segment coils 80 from the input terminal 70 side of each phase is such that the connection to the segment coil 80 inserted in the third layer and the connection to the segment coil 80 inserted in the fourth layer are after the connection to the outer circumference layer connection section Ro in the inner winding section of the respective phase coil. In a three-phase coil 24, when segment coils 80 of the same phase are adjacent within the same slot 22s, the larger the difference in the connection order from the common input terminal 70 side of those adjacent segment coils 80 (=|Nu1-Nu2|), the greater the voltage applied between these adjacent segment coils 80. In a three-phase coil 24, when segment coils 80 of different phases are adjacent within the same slot 22s, the smaller the sum of the connection orders from the input terminal 70 side of each phase of those adjacent segment coils 80 (=Nu3+Nv3), the greater the voltage applied between these adjacent segment coils 80.In this embodiment, the maximum voltage difference between adjacent segment coils 80 in the same slot 22s occurs when segment coils 80 of different phases are adjacent within the same slot 22s in the three-phase coil 24. With the configuration of (b) above, segment coils 80 of different phases are adjacent within the same slot 22s when a segment coil 80 inserted in the third layer and a segment coil 80 inserted in the fourth layer are adjacent. With the configurations of (c) to (e) above, regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the third layer is made after the connection to the outer layer connection part Ro in the inner winding portion of each phase coil. Similarly, regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the fourth layer is made after the connection to the outer layer connection part Ro in the inner winding portion of each phase coil. As a result, the impedance between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer, when viewed from the input terminal 70 side of each phase, is reduced according to the number of segment coils 80 connected at the outer layer connection part Ro of the inner winding of each phase coil. Therefore, in the case of configuration (c) to (e), the maximum value of the impedance between adjacent segment coils 80 of different phases within the same slot 22s is smaller compared to the case where, for example, Comparative Example 1 is not used. When the maximum value of the impedance is smaller, the maximum value of the voltage difference between adjacent segment coils 80 of different phases within the same slot 22s is also smaller. Therefore, the insulating coating of the segment coil 80 can be thinned to improve the space factor. As a result, for example, the size of the rotating electric machine 10 can be reduced while maintaining the same performance, or the performance of the rotating electric machine 10 can be improved while maintaining the same performance.

[0078] In this embodiment, the first coil section 42 has an inner winding section 42a and an outer winding section 42b, each having an outer circumferential layer connection section Ro, an inner circumferential layer connection section Ri, an intermediate layer connection section Rm, an outer circumferential layer-side transfer section SWo connecting the end of the outer circumferential layer connection section Ro to the end of the intermediate layer connection section Rm, and an inner circumferential layer-side transfer section SWi connecting the end of the inner circumferential layer connection section Ri to the end of the intermediate layer connection section Rm. The second coil section 44 of the U-phase coil 40, the first coil section 52 and the second coil section 54 of the V-phase coil 50, and the first coil section 62 and the second coil section 64 of the W-phase coil 60 have a similar connection structure. As a result, by appropriately increasing or decreasing the number of pitches of the outer circumferential layer connection section Ro, the intermediate layer connection section Rm, and the inner circumferential layer connection section Ri, a distributed winding three-phase coil 24 corresponding to the number of slots 22s, which is six times the number of poles of the rotor 30, can be easily constructed. For example, in this embodiment, the number of slots 22s was "24," but by reducing the number of pitches of the outer layer connection part Ro, the intermediate layer connection part Rm, and the inner layer connection part Ri by 12, a three-phase coil 24 can be configured in which the number of slots 22s is "12" and the number of poles of the rotor 30 is "2." By increasing the number of pitches of the outer layer connection part Ro, the intermediate layer connection part Rm, and the inner layer connection part Ri by 12, a three-phase coil 24 can be configured in which the number of slots 22s is "36" and the number of poles of the rotor 30 is "6."

[0079] In this embodiment, in the U-phase coil 40, the outer circumferential layer connection part Ro, the intermediate layer connection part Rm, and the inner circumferential layer connection part Ri in the inner winding portions 42a and 44a are all rotated in the same direction in the circumferential direction. When the outer circumferential layer connection part Ro, the intermediate layer connection part Rm, and the inner circumferential layer connection part Ri in the inner winding portions 42a and 44a are all rotated in the same direction, the bending direction of the segment coil 80 can be unified to be the same in the outer circumferential layer connection part Ro, the intermediate layer connection part Rm, and the inner circumferential layer connection part Ri, compared to when they are not. The same applies to the V-phase coil 50 and the W-phase coil 60. The "bending direction" referred to here is the direction in which the tip portions 82t of each pair of arms 82 of the segment coil 80 are bent in the circumferential and radial directions. Specifically, it is the direction shown by the solid line in Figure 5(a). This results in a repeating pattern for the bending and welding processes of the segment coil 80, improving the workability of the winding process of the three-phase coil 24.

[0080] In this embodiment, in the first coil section 42, the direction in which the segment coil 80 in the inner winding section 42a rotates circumferentially is opposite to the direction in which the segment coil 80 in the outer winding section 42b rotates circumferentially. This allows the inner winding section 42a and the outer winding section 42b of the U-phase coil 40 to have a simple double-helix configuration. For example, the bending and welding processes of the segment coil 80 become a repeating pattern, improving the workability of the winding process of the three-phase coil 24. The same applies to the second coil section 44 of the U-phase coil 40, the first coil section 52 and the second coil section 54 of the V-phase coil 50, and the first coil section 62 and the second coil section 64 of the W-phase coil 60.

[0081] According to this embodiment, in the first coil section 42, (a) in the outer peripheral layer connection section Ro and the inner peripheral layer connection section Ri, the number of pitches on the connecting section 84 side and the welded section 88 side of the segment coil 80 is 6 in both cases, (b) in the intermediate layer connection section Rm, the number of pitches on the connecting section 84 side and the welded section 88 side of the segment coil 80 is 7 on the connecting section 84 side and 5 on the welded section 88 side, and (c) in the outer peripheral layer transfer section SWo and the inner peripheral layer transfer section SWi, the number of pitches on the connecting section 84 side of the segment coil 80 is 6. The same applies to the second coil section 44 of the U-phase coil 40, the first coil section 52 and the second coil section 54 of the V-phase coil 50, and the first coil section 62 and the second coil section 64 of the W-phase coil 60. By using the segment coil 80 configured as described in (a) to (c) above, the segment coils 80 of the same phase in the three-phase coil 24 are arranged such that three are inserted on the outer circumference of one pair of circumferentially adjacent slots 22s out of the 24 slots 22s, and three are inserted on the inner circumference of another pair of slots 22s that are shifted by one slot 22s in the circumferential direction relative to the first pair of slots 22s. Furthermore, the types of segment coils 80 used to constitute the three-phase coil 24 are limited to those with different pitch numbers on the connecting portion 84 side and the welded portion 88 side.

[0082] According to this embodiment, (a) the three-phase coil 24 is Y-connected, (b) a first coil section 42 and a second coil section 44 connected in parallel are provided between the U-phase terminal 72 and the neutral point N, (c) a first coil section 52 and a second coil section 54 connected in parallel are provided between the V-phase terminal 74 and the neutral point N, (d) a first coil section 62 and a second coil section 64 connected in parallel are provided between the W-phase terminal 76 and the neutral point N, and (e) the connection structure of the segment coil 80 of the first coil section 42 and the second coil section 44 within the U-phase coil 40, the connection structure of the segment coil 80 of the first coil section 52 and the second coil section 54 within the V-phase coil 50, and the connection structure of the segment coil 80 of the first coil section 62 and the second coil section 64 within the W-phase coil 60 are all the same. Thus, when the connection structures of the segment coils 80 within each phase coil are identical, the complexity of the connection structure is avoided and the structure is simplified compared to cases where they are not identical. For example, the bending and welding processes of the segment coils 80 become repeating patterns, improving the workability of the winding process of the three-phase coil 24.

[0083] In this embodiment, the phase coils of the three-phase coil 24 are arranged in the first coil sections 42, 52, 62 and the second coil sections 44, 54, 64, respectively, with segment coils 80 having the same connection sequence from the input terminal 70 side of each phase coil inserted into circumferentially adjacent slots 22s. For example, by inserting segment coils 80 having the same connection sequence from the U-phase terminal 72 side into circumferentially adjacent slots 22s in the first coil section 42 and the second coil section 44, the connection structures of the first coil section 42 and the second coil section 44 become identical. In this way, when the connection structures of the first coil section 42 and the second coil section 44 are identical, the complexity of the connection structure is avoided and the structure is simplified compared to when they are not. For example, the bending and welding processes of the segment coils 80 become a repeating pattern, further improving the workability of the winding process of the three-phase coil 24. [Examples]

[0084] Figure 11 is an arrangement diagram of segment coils 80 that constitute a three-phase coil 124 wound around the stator core 22 of a rotating electric machine 110 according to Embodiment 2 of the present invention. Figure 12 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 124 shown in Figure 11, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 124, (b) is a diagram illustrating the details of the connection structure of the U-phase coil 140, and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 124. In Figures 12(a) and 12(b), the dashed line represents the connection portion 84 side of the segment coil 80, and the solid line represents the welded portion 88 side.

[0085] The rotating electric machine 110 has substantially the same configuration as the rotating electric machine 10 according to Embodiment 1 described above, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 140, V-phase coil 150, and W-phase coil 160, respectively. The U-phase coil 140, V-phase coil 150, and W-phase coil 160 each correspond to the "phase coils" in the present invention. The connection structure of the U-phase coil 140, V-phase coil 150, and W-phase coil 160 differs in part from that of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. Therefore, in this embodiment, the explanation will focus on the parts that differ from Embodiment 1, and parts that are substantially common in function with Embodiment 1 will be given the same reference numerals and their explanations will be omitted as appropriate. In this embodiment, the first coil section 142, the second coil section 144, the first coil section 152, the second coil section 154, the first coil section 162, and the second coil section 164 correspond to the first coil section 42, the second coil section 44, the first coil section 52, the second coil section 54, the first coil section 62, and the second coil section 64 in the aforementioned Embodiment 1. In this embodiment, the inner winding portions 142a, 144a, 152a, 154a, 162a, 164a, the outer winding portions 142b, 144b, 152b, 154b, 162b, 164b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends are configured to correspond to the inner winding portions 42a, 44a, 52a, 54a, 62a, 64a, the outer winding portions 42b, 44b, 52b, 54b, 62b, 64b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends in the aforementioned Embodiment 1.

[0086] As shown in Figure 12(a), the V-phase coil 150 is the same as the U-phase coil 140, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 160 is the same as the U-phase coil 140, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. In the first coil section 142 and the second coil section 144 of the U-phase coil 140, segment coils 80 with the same connection order from the U-phase terminal 72 side are inserted into circumferentially adjacent slots 22s. Therefore, in the following, we will describe the connection structure of the segment coil 80 constituting the first coil section 142 as a representative example, and descriptions of other connection structures will be omitted as appropriate.

[0087] As shown in Figures 12(a) and 12(b), the first coil portion 142 of the U-phase coil 140 has an inner winding portion 142a, an outer winding portion 142b, and inner end connecting portions Ji1 and Ji2 that connect the inner ends of these portions.

[0088] The inner winding section 142a has substantially the same connection structure as the inner winding section 42a described above, but differs in that the direction in which the intermediate layer connection section Rm rotates in the circumferential direction is reversed. Specifically, as shown in Figure 12(b), in the drawing, in the inner winding section 142a, the outer circumferential layer connection section Ro rotates to the left, the intermediate layer connection section Rm rotates to the right, and the inner circumferential layer connection section Ri rotates to the left. In the outer winding section 142b, the outer circumferential layer connection section Ro rotates to the right, the intermediate layer connection section Rm rotates to the left, and the inner circumferential layer connection section Ri rotates to the right. Thus, in the inner winding section 142a and the outer winding section 142b, the intermediate layer connection section Rm rotates in the opposite direction to the outer circumferential layer connection section Ro and the inner circumferential layer connection section Ri. Furthermore, the inner winding portion 142a and the outer winding portion 142b have a double helix connection structure at the outer peripheral layer connection portion Ro, the intermediate layer connection portion Rm, and the inner peripheral layer connection portion Ri, respectively.

[0089] At the outer layer connection Ro and the inner layer connection Ri, the pitch count of the segment coil 80 on the connecting portion 84 side (dashed line side shown in Figure 12(a)) and the welded portion 88 side (solid line side shown in Figure 12(a)) is 6. At the intermediate layer connection Rm, the pitch count of the segment coil 80 on the connecting portion 84 side and the welded portion 88 side is 7 and 5 on the connecting portion 84 side. At the outer layer transfer portion SWo and the inner layer transfer portion SWi, the pitch count of the segment coil 80 on the connecting portion 84 side is 6. For segment coils 80 in which both of a pair of arm portions 82 are inserted into the first layer and segment coils 80 in which both of a pair of arm portions 82 are inserted into the sixth layer, the pitch count of the segment coil 80 on the connecting portion 84 side is both 5 and 7.

[0090] Figure 13 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 124 shown in Figure 12, and represents the voltage difference between adjacent segment coils 80. Figure 13 is a diagram representing the voltage difference between adjacent segment coils 80 within the same slot 22s, and the value is obtained by dividing each voltage difference by (1 / 46 × Vo) [V].

[0091] As shown in Figure 13, the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S8 is at its maximum value (=35 / 46 × Vo). In Figure 13, the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. In this embodiment, compared to Comparative Example 1 described above, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by approximately 22.2[%]{=1-(35 / 45)}.

[0092] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration. [Examples]

[0093] Figure 14 is an arrangement diagram of segment coils 80 that constitute a three-phase coil 224 wound around the stator core 22 of a rotating electric machine 210 according to Embodiment 3 of the present invention. Figure 15 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 224 shown in Figure 14, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 224, (b) is a diagram illustrating the details of the connection structure of the U-phase coil 240, and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 224. In Figures 15(a) and 15(b), the dashed line represents the connection portion 84 side of the segment coil 80, and the solid line represents the welded portion 88 side.

[0094] The rotating electric machine 210 has substantially the same configuration as the rotating electric machine 10 according to the above-described embodiment 1, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 240, V-phase coil 250, and W-phase coil 260, respectively. The U-phase coil 240, V-phase coil 250, and W-phase coil 260 each correspond to the "phase coils" in the present invention. The connection structure of the U-phase coil 240, V-phase coil 250, and W-phase coil 260 differs in part from that of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. Therefore, in this embodiment, the explanation will focus on the parts that differ from embodiment 1, and parts that are substantially common in function with embodiment 1 will be given the same reference numerals and their explanations will be omitted as appropriate. In this embodiment, the first coil section 242, the second coil section 244, the first coil section 252, the second coil section 254, the first coil section 262, and the second coil section 264 correspond to the first coil section 42, the second coil section 44, the first coil section 52, the second coil section 54, the first coil section 62, and the second coil section 64 in the aforementioned Embodiment 1. In this embodiment, the inner winding portions 242a, 244a, 252a, 254a, 262a, 264a, outer winding portions 242b, 244b, 252b, 254b, 262b, 264b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends are configured to correspond to the inner winding portions 42a, 44a, 52a, 54a, 62a, 64a, outer winding portions 42b, 44b, 52b, 54b, 62b, 64b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends in the aforementioned Embodiment 1.

[0095] As shown in Figure 15(a), the V-phase coil 250 is the same as the U-phase coil 240, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 260 is the same as the U-phase coil 240, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. In the first coil section 242 and the second coil section 244 of the U-phase coil 240, segment coils 80 with the same connection order from the U-phase terminal 72 side are inserted into circumferentially adjacent slots 22s. Therefore, in the following, we will describe the connection structure of the segment coil 80 constituting the first coil section 242 as a representative example, and descriptions of other connection structures will be omitted as appropriate.

[0096] As shown in Figures 15(a) and 15(b), the first coil portion 242 of the U-phase coil 240 has an inner winding portion 242a, an outer winding portion 242b, and inner end connecting portions Ji1 and Ji2 that connect the inner ends of these portions.

[0097] The inner winding section 242a has substantially the same connection structure as the inner winding section 42a described above, but differs in that the direction in which the inner circumferential layer connection section Ri rotates in the circumferential direction is reversed. Specifically, as shown in Figure 15(b), in the drawing, in the inner winding section 242a, the outer circumferential layer connection section Ro rotates to the left, the intermediate layer connection section Rm rotates to the left, and the inner circumferential layer connection section Ri rotates to the right. In the outer winding section 242b, the outer circumferential layer connection section Ro rotates to the right, the intermediate layer connection section Rm rotates to the right, and the inner circumferential layer connection section Ri rotates to the left. Thus, in the inner winding section 242a and the outer winding section 242b, the inner circumferential layer connection section Ri rotates in the opposite direction to the outer circumferential layer connection section Ro and the intermediate layer connection section Rm. Furthermore, the inner winding portion 242a and the outer winding portion 242b have a double helix connection structure at the outer peripheral layer connection portion Ro, the intermediate layer connection portion Rm, and the inner peripheral layer connection portion Ri, respectively.

[0098] As shown in Figure 15(c), the type of segment coil 80 used to constitute the three-phase coil 224 in this embodiment is the same as that of Embodiment 1 described above.

[0099] Figure 16 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 224 shown in Figure 15, and represents the voltage difference between adjacent segment coils 80. Figure 16 is a diagram representing the voltage difference between adjacent segment coils 80 within the same slot 22s, and the value is obtained by dividing each voltage difference by (1 / 46 × Vo) [V].

[0100] The voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S12, and the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S16, are both at their maximum value (=35 / 46 × Vo). In Figure 16, the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. In this embodiment, compared to Comparative Example 1 described above, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by 22.2[%]{=1-(35 / 45)}.

[0101] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration. [Examples]

[0102] Figure 17 is an arrangement diagram of segment coils 80 constituting a three-phase coil 324 wound around the stator core 22 of a rotating electric machine 310 according to Embodiment 4 of the present invention. Figure 18 is a diagram illustrating the connection structure of the segment coils 80 constituting the three-phase coil 324 shown in Figure 17, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 324, (b) is a diagram illustrating the details of the connection structure of the U-phase coil 340, and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 324. In Figures 18(a) and 18(b), the dashed line represents the connection portion 84 side of the segment coil 80, and the solid line represents the welded portion 88 side.

[0103] The rotating electric machine 310 has substantially the same configuration as the rotating electric machine 10 according to the above-described embodiment 1, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 340, V-phase coil 350, and W-phase coil 360, respectively. The U-phase coil 340, V-phase coil 350, and W-phase coil 360 correspond to the "phase coils" in the present invention. The connection structure of the U-phase coil 340, V-phase coil 350, and W-phase coil 360 differs in part from that of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. Therefore, in this embodiment, the explanation will focus on the parts that differ from embodiment 1, and parts that are substantially common in function with embodiment 1 will be given the same reference numerals and their explanations will be omitted as appropriate. In this embodiment, the first coil section 342, the second coil section 344, the first coil section 352, the second coil section 354, the first coil section 362, and the second coil section 364 correspond to the first coil section 42, the second coil section 44, the first coil section 52, the second coil section 54, the first coil section 62, and the second coil section 64 in the aforementioned Embodiment 1. In this embodiment, the inner winding portions 342a, 344a, 352a, 354a, 362a, 364a, the outer winding portions 342b, 344b, 352b, 354b, 362b, 364b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends are configured to correspond to the inner winding portions 42a, 44a, 52a, 54a, 62a, 64a, the outer winding portions 42b, 44b, 52b, 54b, 62b, 64b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends in the aforementioned Embodiment 1.

[0104] As shown in Figure 18(a), the V-phase coil 350 is the same as the U-phase coil 340, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 360 is the same as the U-phase coil 340, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. In the first coil section 342 and the second coil section 344 of the U-phase coil 340, segment coils 80 with the same connection order from the U-phase terminal 72 side are inserted into circumferentially adjacent slots 22s. Therefore, in the following, we will describe the connection structure of the segment coil 80 constituting the first coil section 342 as a representative example, and descriptions of other connection structures will be omitted as appropriate.

[0105] As shown in Figures 18(a) and 18(b), the first coil portion 342 of the U-phase coil 340 has an inner winding portion 342a, an outer winding portion 342b, and inner end connecting portions Ji1 and Ji2 that connect the inner ends of these portions.

[0106] The inner winding portion 342a has substantially the same connection structure as the inner winding portion 42a described above, but the U-phase coil 340 differs in that it does not have the outer peripheral end connection portions Jo1 and Jo2 as in the above-described embodiment 1. Specifically, as shown in Figure 18(b), the outer peripheral layer connection portion Ro starts to rotate circumferentially from the first layer to which the U-phase terminal 72 is connected to the second layer, meaning that there is no segment coil 80 connecting the first layers together.

[0107] In the outer layer connection section Ro and the inner layer connection section Ri, the pitch number of the segment coil 80 on the connecting section 84 side (dashed line side shown in Figure 18(a)) and the welded section 88 side (solid line side shown in Figure 18(a)) is 6. In the intermediate layer connection section Rm, the pitch number of the segment coil 80 on the connecting section 84 side and the welded section 88 side is 7 on the welded section 88 side and 5 on the connecting section 84 side. In the outer layer transition section SWo and the inner layer transition section SWi, the pitch number of the segment coil 80 on the welded section 88 side is 6. In this embodiment, there are no segment coils 80 in which both of the pair of arms 82 are inserted into the first layer, nor are there any segment coils 80 in which both of the pair of arms 82 are inserted into the sixth layer.

[0108] Figure 19 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 324 shown in Figure 18, and represents the voltage difference between adjacent segment coils 80. Figure 19 is a diagram representing the voltage difference between adjacent segment coils 80 within the same slot 22s, and the value is obtained by dividing each voltage difference by (1 / 46 × Vo) [V].

[0109] The voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S12, and the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S16, are both at their maximum value (=37 / 46 × Vo). In Figure 19, the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. In this embodiment, compared to Comparative Example 1 described above, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by approximately 17.7[%]{=1-(37 / 45)}.

[0110] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration. [Examples]

[0111] Figure 20 is an arrangement diagram of segment coils 80 that constitute a three-phase coil 424 wound around the stator core 22 of a rotating electric machine 410 according to Embodiment 5 of the present invention. Figure 21 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 424 shown in Figure 20, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 424, and (b) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 424. In Figure 21(a), the dashed line represents the connection portion 84 side of the segment coil 80, and the solid line represents the welded portion 88 side.

[0112] The rotating electric machine 410 has substantially the same configuration as the rotating electric machine 10 according to Embodiment 1 described above, but differs in that the U-phase coil 440, V-phase coil 450, and W-phase coil 460 are used instead of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. The U-phase coil 440, V-phase coil 450, and W-phase coil 460 correspond to the "phase coils" in the present invention. The U-phase coil 440 and W-phase coil 460 have the same connection structure as the U-phase coil 40 and W-phase coil 60, respectively. The V-phase coil 450 has substantially the same connection structure as the V-phase coil 50, but the inward winding start position A1 of the outer peripheral layer connection part Ro of the V-phase coil 450 is different from that in Embodiment 1. Therefore, in this embodiment, the explanation will focus on the parts that differ from Embodiment 1, and parts that are substantially common in function with Embodiment 1 will be given the same reference numerals and their explanations will be omitted as appropriate. In this embodiment, the first coil section 442, the second coil section 444, the first coil section 452, the second coil section 454, the first coil section 462, and the second coil section 464 correspond to the first coil section 42, the second coil section 44, the first coil section 52, the second coil section 54, the first coil section 62, and the second coil section 64 in the aforementioned Embodiment 1. In this embodiment, the inner winding portions 442a, 444a, 452a, 454a, 462a, 464a, outer winding portions 442b, 444b, 452b, 454b, 462b, 464b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends are configured to correspond to the inner winding portions 42a, 44a, 52a, 54a, 62a, 64a, outer winding portions 42b, 44b, 52b, 54b, 62b, 64b, and the inner end connecting portions Ji1, Ji2 that connect their inner ends in the aforementioned Embodiment 1.

[0113] As shown in Figures 20 and 21, the V-phase coil 450 has a connection structure in which the connection structure of the segment coil 80 constituting the U-phase coil 440 is shifted to the right by 2 pitches of slot 22s in the circumferential direction, and the insertion positions of the first coil section 442 and the second coil section 444 are swapped.

[0114] In this embodiment, the inward winding start positions A1 of the first coil section 442 and the second coil section 444 in the U-phase coil 440, the inward winding start positions A1 of the first coil section 452 and the second coil section 454 in the V-phase coil 450, and the inward winding start positions A1 of the first coil section 462 and the second coil section 464 in the W-phase coil 460 are each set to predetermined positions.

[0115] The "predetermined position" is a position predetermined in the design so that the maximum voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of different phases within the same slot 22s is minimized. The "predetermined position" corresponds to the "predetermined position" in this invention.

[0116] In the aforementioned Embodiment 1, when segment coils 80 of different phases are adjacent within the same slot 22s, the connection order from the input terminal 70 side of each phase of the segment coil 80 and the voltage difference between adjacent segment coils 80 are shown in Figure 7(c). In Figure 7(c), it is possible to shift the insertion positions of the V-phase segment coils 80 (V6a, V20a, V21b, V9b, V8a, V18a, V19b, V7b) by 6 pitches with respect to the insertion positions of the U-phase segment coils 80 (U19b, U7b, U6a, U20a, U21b, U9b, U8a, U18a). That is, in the V-phase coil 450, it is possible to shift the inward winding start position A1 of the first coil section 452 and the second coil section 454 by 6 pitches. Similarly, with respect to the insertion positions of the U-phase segment coils 80 (U19b, U7b, U6a, U20a, U21b, U9b, U8a, U18a), the insertion positions of the W-phase segment coils 80 (W20a, W21b, W9b, W8a, W18a, W19b, W7b, W6a) can be shifted by 6 pitches. That is, in the W-phase coil 460, the inward winding start position A1 of the first coil section 462 and the second coil section 464 can be shifted by 6 pitches. In this way, from among the combinations in which the amount of shift of the inward winding start position A1 in the U-phase coil 440, V-phase coil 450, and W-phase coil 460 is changed by 6 pitches in the slot 22s, it is possible to pre-determine in the design a combination that results in a lower maximum voltage difference between a segment coil 80 inserted in the third layer and a segment coil 80 inserted in the fourth layer of different phases within the same slot 22s. The "designated location" is, in this way, a location predetermined in the design.

[0117] As shown in Figure 21(b), the type of segment coil 80 used to constitute the three-phase coil 424 is the same as in the previously described embodiment 1.

[0118] Figure 22 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 424 shown in Figure 21, and represents the voltage difference between adjacent segment coils 80. Figure 22 is a diagram representing the voltage difference between adjacent segment coils 80 within the same slot 22s, and the value is obtained by dividing each voltage difference by (1 / 46 × Vo) [V].

[0119] The voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S8, and the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S20, are both at their maximum value (=33 / 46 × Vo). In Figure 22, the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. In this embodiment, compared to Comparative Example 1 described above, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by approximately 26.7[%]{=1-(33 / 45)}. Furthermore, compared to Embodiment 1 described above, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is also reduced.

[0120] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration.

[0121] In this embodiment, in 24 slots 22s, the starting position A1 of the inner winding portions 442a, 444a, 452a, 454a, 462a, and 464a of the U-phase coil 440, V-phase coil 450, and W-phase coil 460 is set at a predetermined position such that the maximum voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of different phases within the same slot 22s is reduced. By setting the starting position A1 of the inner winding portions 442a, 444a, 452a, 454a, 462a, and 464a of the U-phase coil 440, V-phase coil 450, and W-phase coil 460 at a predetermined position, the maximum voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of different phases within the same slot 22s is further reduced. This allows the insulating coating of the segment coil 80 to be made even thinner, improving the space factor. For example, it becomes possible to reduce the size of the rotating electric machine 410 while maintaining the same performance, or to improve the performance of the rotating electric machine 410 while maintaining the same size. [Examples]

[0122] Figure 23 illustrates the connection structure of segment coils 80 that constitute a three-phase coil 524 wound around the stator core 22 of a rotating electric machine 510 according to Embodiment 6 of the present invention, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 524, and (b) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 524. In Figure 23(a), the dashed line represents the connection portion 84 side of the segment coil 80, and the solid line represents the welded portion 88 side.

[0123] The rotating electric machine 510 has substantially the same configuration as the rotating electric machine 10 according to the above-described embodiment 1, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 540, V-phase coil 550, and W-phase coil 560, respectively. The U-phase coil 540, V-phase coil 550, and W-phase coil 560 correspond to the "phase coils" in the present invention. The connection structure of the U-phase coil 540, V-phase coil 550, and W-phase coil 560 differs in part from that of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. Therefore, in this embodiment, the explanation will focus on the parts that differ from embodiment 1, and parts that are substantially common in function with embodiment 1 will be given the same reference numerals and their explanations will be omitted as appropriate. In this embodiment, the first coil section 542, the second coil section 544, the first coil section 552, the second coil section 554, the first coil section 562, and the second coil section 564 correspond to the first coil section 42, the second coil section 44, the first coil section 52, the second coil section 54, the first coil section 62, and the second coil section 64 in the aforementioned Embodiment 1. In this embodiment, the outer circumference end connecting parts Jo3, Jo4, the inner winding parts 542a, 544a, 552a, 554a, 562a, 564a, the outer winding parts 542b, 544b, 552b, 554b, 562b, 564b, and the inner circumference end connecting parts Ji3, Ji4 that connect the inner ends of these parts correspond to the outer circumference end connecting parts Jo1, Jo2, the inner winding parts 42a, 44a, 52a, 54a, 62a, 64a, the outer winding parts 42b, 44b, 52b, 54b, 62b, 64b, and the inner circumference end connecting parts Ji1, Ji2 that connect the inner ends of these parts in the aforementioned Embodiment 1.

[0124] As shown in Figure 23(a), the U-phase coil 540, V-phase coil 550, and W-phase coil 560 differ from the outer circumference end connection parts Jo3, Jo4 and inner circumference end connection parts Ji3, Ji4 of Embodiment 1, respectively. The inner winding parts 542a, 552a, and 562a have the same connection configuration as the inner winding parts 44a, 54a, and 64a in Embodiment 1 described above. The inner winding parts 544a, 554a, and 564a have the same connection configuration as the inner winding parts 42a, 52a, and 62a in Embodiment 1 described above. The outer winding parts 542b, 552b, and 562b have the same connection configuration as the outer winding parts 42b, 52b, and 62b in Embodiment 1 described above. The outer winding sections 544b, 554b, and 564b have the same connection configuration as the outer winding sections 44b, 54b, and 64b in the aforementioned Embodiment 1. Specifically, in the drawing, the inner winding start position A1 of the inner winding section 542a is the first layer of slot number S7, which is shifted 6 pitches to the left from slot number S1 to which the U-phase terminal 72 is connected by the outer peripheral end connection section Jo3. The inner winding start position B1 of the inner winding section 544a is the first layer of slot number S8, which is shifted 6 pitches to the left from slot number S2 to which the U-phase terminal 72 is connected by the outer peripheral end connection section Jo4. In the drawing, the outer winding start position A3 of the outer winding section 542b is the sixth layer of slot number S18, which is shifted 6 pitches to the right from slot number S24, which is the inner winding end position A2, by the inner peripheral end connection section Ji3. The starting position B3 of the outer winding section 544b is the 6th layer of slot number S19, which is shifted 6 pitches to the right from slot number S1, which is the ending position B2 of the inner winding, by the inner end connection section Ji4. The outer end connection sections Jo3 and Jo4 in the V-phase coil 550 and W-phase coil 560 have the same configuration as those in the U-phase coil 540. The inner end connection sections Ji3 and Ji4 in the V-phase coil 550 and W-phase coil 560 have the same configuration as those in the U-phase coil 540.

[0125] As shown in Figure 23(b), the type of segment coil 80 used to constitute the three-phase coil 424 is substantially the same as in the previously described embodiment 1. However, the difference is that on the connecting portion 84 side of the segment coil 80, the number of pitches for the segment coil 80 in which both pairs of arms 82 are inserted into the first layer and the number of pitches for the segment coil 80 in which both pairs of arms 82 are inserted into the sixth layer are both 6.

[0126] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration.

[0127] In this embodiment, on the connecting portion 84 side of the segment coil 80, the number of pitches for both the segment coil 80 in which both arms 82 are inserted into the first layer and the segment coil 80 in which both arms 82 are inserted into the sixth layer are both 6. This makes it possible to reduce the number of types of pitches for the segment coil 80 used to constitute the three-phase coil 524 compared to the embodiments 1 to 4 described above. [Examples]

[0128] Figure 24 is an electrically equivalent circuit diagram of a three-phase coil 624 wound around the stator core 22 of a rotating electric machine 610 according to Embodiment 7 of the present invention. The three-phase coil 624 is Y-connected. The three-phase coil 624 consists of the U-phase coil 640, V-phase coil 650, and W-phase coil 660. The U-phase coil 640, V-phase coil 650, and W-phase coil 660 each correspond to the "phase coils" in the present invention. The rotating electric machine 610 has substantially the same configuration as the rotating electric machine 10 according to Embodiment 1 described above, but differs in that the U-phase coil 40, V-phase coil 50, and W-phase coil 60 are replaced with U-phase coil 640, V-phase coil 650, and W-phase coil 660, respectively. The connection structure of the U-phase coil 640, V-phase coil 650, and W-phase coil 660 differs in part from that of the U-phase coil 40, V-phase coil 50, and W-phase coil 60, respectively. Therefore, in this embodiment, we will focus on explaining the parts that differ from those in Embodiment 1, and parts that are substantially common in function with those in Embodiment 1 will be denoted by the same reference numerals, and their explanations will be omitted as appropriate.

[0129] The U-phase coil 640 has one end connected to the U-phase terminal 72 and the other end connected to the neutral point N. The V-phase coil 650 has one end connected to the V-phase terminal 74 and the other end connected to the neutral point N. The W-phase coil 660 has one end connected to the W-phase terminal 76 and the other end connected to the neutral point N. The U-phase coil 640 is a single coil section provided between the U-phase terminal 72 and the neutral point N. The V-phase coil 650 is a single coil section provided between the V-phase terminal 74 and the neutral point N. The W-phase coil 660 is a single coil section provided between the W-phase terminal 76 and the neutral point N. Thus, each of the U-phase coil 640, V-phase coil 650, and W-phase coil 660 has one end connected to the input terminal 70 of each phase and the other end connected to the neutral point N, with a single coil section provided between the input terminal 70 and the neutral point N. The U-phase coil 640, the V-phase coil 650, and the W-phase coil 660 each correspond to the "coil section" in this invention.

[0130] Here, the positions in which the segment coil 80 of the U-phase coil 640 is inserted into slot 22s will be denoted as insertion positions U1, U2, U3, U4, ..., U47, U48, in order from the U-phase terminal 72 side toward the neutral point N. The positions in which the segment coil 80 of the V-phase coil 650 is inserted into slot 22s will be denoted as insertion positions V1, V2, V3, V4, ..., V47, V48, in order from the V-phase terminal 74 side toward the neutral point N. The positions in which the segment coil 80 of the W-phase coil 660 is inserted into slot 22s will be denoted as insertion positions W1, W2, W3, W4, ..., W47, W48, in order from the W-phase terminal 76 side toward the neutral point N. The leading letters U, V, and W at these insertion points represent the segment coils 80 that constitute the U-phase coil 640, V-phase coil 650, and W-phase coil 660, respectively, while the numerical part represents the connection order from the input terminal 70 side of each phase toward the neutral point N.

[0131] Figure 25 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 624 shown in Figure 24, where (a) is an arrangement diagram of the segment coils 80 and (b) is a diagram illustrating the schematic of the connection structure of the U-phase coil 640. Figure 26 is a diagram illustrating the connection structure of the segment coils 80 that constitute the three-phase coil 624 shown in Figure 25, where (a) is a diagram illustrating the overall structure of the connection structure of the three-phase coil 624, (b) is a diagram illustrating the details of the connection structure of the U-phase coil 640 and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 624. In Figure 25(b), the dashed line represents the connection portion 84 side of the segment coil 80 and the solid line represents the welded portion 88 side. The same applies to Figure 26.

[0132] As shown in Figure 25, the V-phase coil 650 is the same as the U-phase coil 640, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 660 is the same as the U-phase coil 640, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. Therefore, in the following, we will describe the connection structure of the U-phase coil 640 as a representative example, and descriptions of other connection structures will be omitted as appropriate.

[0133] The U-phase coil 640 has two outer circumference end connection parts Jo5, Jo6, two inner winding parts 640a, 640c, two outer winding parts 640b, 640d, and two inner circumference end connection parts Ji5, Ji6. The inner winding part 640a, outer winding part 640b, inner winding part 640c, and outer winding part 640d have the same connection structure as the inner winding part 42a, outer winding part 42b, inner winding part 44a, and outer winding part 44b in the above-described embodiment 1. The inner winding start position C1 is the insertion position at one of the points where the segment coil 80 is first connected from one of the first and second layers to the other at the outer circumference layer connection part Ro of the inner winding part 640a. The inner winding start position C1 corresponds to the "winding start position" in the present invention. The inner winding end position C2 is the insertion position of the 6th layer at the inner circumferential layer connection part Ri of the inner winding section 640a, where the segment coil 80 is last connected from the 5th layer to the 6th layer. The inner winding end position C2 corresponds to the "inner circumferential end of the inner winding section" in this invention. The outer winding start position C3 is the insertion position of the 6th layer at the inner circumferential layer connection part Ri of the outer winding section 640b, where the segment coil 80 is first connected from the 6th layer to the 5th layer. The outer winding start position C3 corresponds to the "inner circumferential end of the outer winding section" in this invention. The outer winding end position C4 is the insertion position of the other side at the outer circumferential layer connection part Ro of the outer winding section 640b, where the segment coil 80 is last connected from one of the 1st and 2nd layers to the other side. The inward winding start position D1 is the insertion position at one of the points where the segment coil 80 is initially connected from one of the 1st and 2nd layers to the other at the outer circumferential layer connection Ro of the inward winding section 640c. The inward winding end position D2 is the insertion position of the 6th layer at the point where the segment coil 80 is last connected from the 5th layer to the 6th layer at the inner circumferential layer connection Ri of the inward winding section 640c. The inward winding end position D2 corresponds to the "inner circumferential end of the inward winding section" in this invention. The outward winding start position D3 is the insertion position of the 6th layer at the point where the segment coil 80 is initially connected from the 6th layer to the 5th layer at the inner circumferential layer connection Ri of the outward winding section 640d. The outward winding start position D3 corresponds to the "inner circumferential end of the outward winding section" in this invention.The outer winding end position D4 is the insertion position of the other end of the outer layer connection portion Ro of the outer winding portion 640d, where the segment coil 80 is last connected from one of the first and second layers to the other.

[0134] The inner circumference end connection part Ji5 is the portion where the segment coil 80 is positioned between the inner winding end position C2 and the outer winding start position C3. The inner circumference end connection part Ji6 is the portion where the segment coil 80 is positioned between the inner winding end position D2 and the outer winding start position D3. The outer circumference end connection part Jo5 is the portion where the segment coil 80 is positioned between the U-phase terminal 72 and the inner winding start position C1, and is the portion that connects the first layers of the segment coils 80 that are inserted into each other. The outer circumference end connection part Jo6 is the portion where the segment coil 80 is positioned between the outer winding end position C4 and the inner winding start position D1, and is the portion that connects the first layers of the segment coils 80 that are inserted into each other.

[0135] The connection structure of the outer circumference end connection part Jo5, the inner winding part 640a, the inner circumference end connection part Ji5, and the outer winding part 640b is the connection structure for "insertion positions U1 to U24" shown in Figure 25(b), and is the same as the connection structure of the outer circumference end connection part Jo1, the inner winding part 42a, the inner circumference end connection part Ji1, and the outer winding part 42b in the above-described embodiment 1. The connection structure of the outer circumference end connection part Jo6, the inner winding part 640c, the inner circumference end connection part Ji6, and the outer winding part 640d is the connection structure for "insertion positions U25 to U48" shown in Figure 25(b), and is the same as the connection structure of the outer circumference end connection part Jo2, the inner winding part 44a, the inner circumference end connection part Ji2, and the outer winding part 44b in the above-described embodiment 1.

[0136] The outer winding end position C4 of the outer winding portion 640b is connected to the inner winding portion 640c via the outer peripheral end connection portion Jo6. Specifically, the second layer of slot number S7 and the first layer of slot number S7 are connected via the outer peripheral end connection portion Jo6.

[0137] The inner winding portion 640a and the outer winding portion 640b each have an outer peripheral layer connecting portion Ro, an outer peripheral layer transfer portion SWo, an intermediate layer connecting portion Rm, an inner peripheral layer transfer portion SWi, and an inner peripheral layer connecting portion Ri, similar to the inner winding portion 42a and the outer winding portion 42b in the above-described embodiment 1. The inner winding portion 640c and the outer winding portion 640d each have an outer peripheral layer connecting portion Ro, an outer peripheral layer transfer portion SWo, an intermediate layer connecting portion Rm, an inner peripheral layer transfer portion SWi, and an inner peripheral layer connecting portion Ri, similar to the inner winding portion 44a and the outer winding portion 44b in the above-described embodiment 1.

[0138] Regarding the connection sequence of the segment coils 80 from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the third layer is made after the connection to the outer layer connection Ro in the inner winding portion 640a. That is, when viewed from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the third layer is made after the outer layer connection Ro of the inner winding portion 640a has rotated in the circumferential direction, or after the outer layer connection Ro of the inner winding portion 640a has rotated in the circumferential direction and further after the inner circumferential layer connection Ri of the outer winding portion 640b has rotated in the circumferential direction. Regarding the connection sequence of the segment coils 80 from the U-phase terminal 72 side, the connection to the segment coil 80 inserted in the fourth layer is made after the connection to the outer layer connection Ro in the inner winding portion 640a. In other words, the connection to the segment coil 80 inserted in the fourth layer when viewed from the U-phase terminal 72 side is made after the outer circumferential layer connection part Ro of the inner winding part 640a has rotated in the circumferential direction, or after the outer circumferential layer connection part Ro of the inner winding part 640a has rotated in the circumferential direction and further after the inner circumferential layer connection part Ri of the outer winding part 640b has rotated in the circumferential direction. Thus, the connection to the segment coil 80 inserted in the third layer and the connection to the segment coil 80 inserted in the fourth layer when viewed from the U-phase terminal 72 side are both made after the outer circumferential layer connection part Ro of the inner winding part 640a has rotated in the circumferential direction.

[0139] As shown in Figure 26(c), the type of segment coil 80 used to constitute the three-phase coil 624 in this embodiment is substantially the same as that of Embodiment 1 described above.

[0140] Figure 27 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 624 shown in Figure 26, where (a) is a diagram illustrating the relationship between the voltage difference between adjacent segment coils 80 and the connection order from the input terminal 70 side of the segment coils 80, (b) is a diagram showing the voltage difference between adjacent segment coils 80, and (c) is a diagram showing the connection order from the input terminal 70 side of each phase of the segment coils 80 and the voltage difference between adjacent segment coils 80 when segment coils 80 of different phases are adjacent within the same slot 22s.

[0141] As shown in Figure 27(a), adjacent segment coils 80 within the same slot 22s are arranged alternately in the circumferential direction between slots 22s in which only six segment coils 80 of the same phase are inserted, and slots 22s in which three segment coils 80 of different phases are inserted. In Figure 27(a), the locations where segment coils 80 of different phases are adjacent within the same slot 22s are indicated by inverted black and white text.

[0142] From here, using Figure 24, we will explain the voltage difference between adjacent segment coils 80 within the same slot 22s. When the rotating electric machine 610 is driven to rotate, a three-phase AC voltage is applied to the U-phase terminal 72, the V-phase terminal 74, and the W-phase terminal 76, respectively. The voltage difference between adjacent segment coils 80 within the same slot 22s can be calculated in the following cases: between U-phase coil 640 segment coils 80, between V-phase coil 650 segment coils 80, between W-phase coil 660 segment coils 80, between U-phase coil 640 segment coil 80 and V-phase coil 650 segment coil 80, between V-phase coil 650 segment coil 80 and W-phase coil 660 segment coil 80, and between W-phase coil 660 segment coil 80 and U-phase coil 640 segment coil 80. The voltage difference can be calculated using different methods for segment coils 80 of the same phase and segment coils 80 of different phases. Therefore, we will explain, as representative examples, the case between two segment coils 80 of the U-phase coil 640, and the case between a segment coil 80 of the U-phase coil 640 and a segment coil 80 of the V-phase coil 650.

[0143] In the following explanation, for the sake of ease of understanding, we will simplify the explanation by assuming that the segment coil 80 wound around the stator core 22, which is made of electromagnetic steel sheet, functions as an ideal inductive reactance. Here, the impedance, which is the inductive reactance between the U-phase terminal 72 and the V-phase terminal 74, is denoted as impedance Z2 [Ω].

[0144] Between the U-phase terminal 72 and the neutral point N, there are a total of 47 locations, alternating between the locations on the connecting portion 84 side of the segment coil 80 and the locations on the welded portion 88 side where the tip portions 82t are welded together. There are 24 locations on the connecting portion 84 side and 23 locations on the welded portion 88 side. The same applies between the V-phase terminal 74 and the neutral point N.

[0145] For example, when a voltage Vo [V] is applied to the U-phase terminal 72 relative to the V-phase terminal 74, a current Io (=Vo / Z2) [A] flows between the U-phase terminal 72 and the V-phase terminal 74. In this case, (1 / 94 × Vo) [V] is applied to the connection portion 84 and the welded portion 88 of the segment coil 80, respectively, between the U-phase terminal 72 and the V-phase terminal 74. In the U-phase coil 640, the potential decreases by (1 / 94 × Vo) [V] for each increase in the connection sequence from the U-phase terminal 72 towards the neutral point N. In the V-phase coil 650, the potential increases by (1 / 94 × Vo) [V] for each increase in the connection sequence from the V-phase terminal 74 towards the neutral point N.

[0146] First, we will explain the case where adjacent segment coils 80 within the same slot 22s are in phase, for example, when one segment coil 80 has its U-phase coil 640 inserted at connection order Nu4, and another segment coil 80 has its U-phase coil 640 inserted at connection order Nu5, and these are adjacent. Connection orders Nu4 and Nu5 correspond to the numerical part of the insertion position (U1 to U48). In this case, the voltage difference between adjacent segment coils 80 is the difference in connection order (=|Nu4-Nu5|) from the common input terminal U-phase terminal 72 side toward the neutral point N, multiplied by (1 / 94×Vo)[V]. Note that the maximum value of the difference in connection order from the common input terminal 70 side toward the neutral point N of adjacent in-phase segment coils 80 is "47", which is the difference between the maximum value (=48) and the minimum value (=1) of the connection order.

[0147] Next, we will explain the case where adjacent segment coils 80 within the same slot 22s are of different phases, for example, when one segment coil 80, U-phase coil 640, is inserted at connection order Nu6, and another segment coil 80, V-phase coil 650, is inserted at connection order Nv6, and these two segments are adjacent. Connection order Nu6 is equivalent to the numerical part of the insertion position (U1~U48), and connection order Nv6 is equivalent to the numerical part of the insertion position (V1~V48). In this case, the total number of connections on the connecting portion 84 side and the welded portion 88 side of the segment coil 80 provided between the insertion position of one segment coil 80 and the insertion position of the other segment coil 80 is called the total T. The total T is the difference between "96" and the sum of connection order Nu6 and connection order Nv6 {=96-(Nu6+Nv6)}. When one segment coil 80 of the U-phase coil 640 and another segment coil 80 of the V-phase coil 650 are adjacent within the same slot 22s, the voltage difference between the adjacent segment coils 80 is obtained by multiplying the total T by (1 / 94 × Vo) [V]. The same method can be used to calculate the voltage difference when a segment coil 80 of the V-phase coil 650 and a segment coil 80 of the W-phase coil 660 are adjacent within the same slot 22s, and when a segment coil 80 of the W-phase coil 660 and a segment coil 80 of the U-phase coil 640 are adjacent within the same slot 22s.

[0148] Returning to Figure 27, as shown in Figure 27(b), the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S12, and the voltage difference between the segment coil 80 inserted in the third layer and the segment coil 80 inserted in the fourth layer of slot number S16, are both at their maximum value (=59 / 94×Vo). In Figure 27(b), the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. As mentioned above, when in-phase segment coils 80 are adjacent within the same slot 22s, the maximum value obtained by dividing the voltage difference between adjacent segment coils 80 by (1 / 94×Vo)[V] is "47".

[0149] Figure 27(c) shows the connection order from the input terminal 70 side of each phase of the segment coil 80 and the voltage difference between adjacent segment coils 80 when segment coils 80 of different phases are adjacent to each other in the same slot 22s.

[0150] Figure 28 illustrates the positional relationship of adjacent segment coils 80 within the three-phase coil 624 shown in Figure 26, when segment coils 80 of different phases are adjacent to each other within the same slot 22s.

[0151] As shown in Figure 28, the outer end connector Jo5, inner winding 640a, inner end connector Ji5, outer winding 640b, outer end connector Jo6, inner winding 640c, inner end connector Ji6, and outer winding 640d are connected in series between the U-phase terminal 72 and the neutral point N. If the inner winding 640a and inner winding 640c are considered the forward path from the outer side to the inner side, then the outer winding 640b and outer winding 640d are considered the return path from the inner side to the outer side. The outer end connector Jo5, inner winding 650a, inner end connector Ji5, outer winding 650b, outer end connector Jo6, inner winding 650c, inner end connector Ji6, and outer winding 650d are connected in series between the V-phase terminal 74 and the neutral point N. Between the W-phase terminal 76 and the neutral point N, the outer circumference end connection part Jo5, the inner winding part 660a, the inner circumference end connection part Ji5, the outer winding part 660b, the outer circumference end connection part Jo6, the inner winding part 660c, the inner circumference end connection part Ji6, and the outer winding part 660d are connected in series.

[0152] When segment coils 80 of different phases are adjacent within the same slot 22s, these adjacent segment coils 80 are a combination of a segment coil 80 inserted in the third layer and a segment coil 80 inserted in the fourth layer. Regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the third layer is made after the connection to the outer layer Ro in the inner winding portion of each phase coil. Similarly, regarding the connection order of the segment coils 80 from the input terminal 70 side of each phase, the connection to the segment coil 80 inserted in the fourth layer is made after the connection to the outer layer Ro in the inner winding portion of each phase coil. In Figure 28, when segment coils 80 of different phases are adjacent within the same slot 22s, the positional relationship of the adjacent segment coils 80 is shown with dashed arrows.

[0153] Figure 29 illustrates the connection structure of the segment coils 80 constituting the three-phase coil 924 according to Comparative Example 2, where (a) is an arrangement diagram of the segment coils 80, (b) is a diagram illustrating the schematic of the connection structure of the U-phase coil 940, and (c) is a diagram illustrating the types of segment coils 80 used to constitute the three-phase coil 924. The three-phase coil 924 has substantially the same configuration as the three-phase coil 824 according to Comparative Example 1, but differs in that the U-phase coil 940, V-phase coil 950, and W-phase coil 960 are used instead of the U-phase coil 840, V-phase coil 850, and W-phase coil 860, respectively. In this comparative example, the explanation will focus on the parts that differ from Comparative Example 1, and parts that are substantially common in function with Comparative Example 1 will be given the same reference numerals and their explanations will be omitted as appropriate.

[0154] In Figure 29(a), each region of insertion position where the in-phase segment coil 80 is inserted is shown enclosed by a thick solid line.

[0155] As shown in Figure 29(a), the V-phase coil 950 is the same as the U-phase coil 940, but with the connection structure of the segment coil 80 shifted to the left by 4 pitches. The W-phase coil 960 is the same as the U-phase coil 940, but with the connection structure of the segment coil 80 shifted to the left by 8 pitches. Therefore, in the following, we will describe the connection structure of the U-phase coil 940 as a representative example, and descriptions of other connection structures will be omitted as appropriate.

[0156] As shown in Figure 29(b), the U-phase coil 940 has a portion on the connecting portion 84 side of the segment coil 80 where the tip portions 82t of a segment coil 80 in which both of a pair of arm portions 82 are inserted into the first layer, a segment coil 80 in which both of a pair of arm portions 82 are inserted into the second and third layers, and a segment coil 80 in which both of a pair of arm portions 82 are inserted into the fourth and fifth layers are sequentially connected, resulting in a zigzag connection from the outer circumference to the inner circumference. The U-phase coil 940 has a portion on the connecting portion 84 side of the segment coil 80 where the tip portions 82t of a segment coil 80 in which both of a pair of arm portions 82 are inserted into the sixth layer, a segment coil 80 in which both of a pair of arm portions 82 are inserted into the fifth and fourth layers, and a segment coil 80 in which both of a pair of arm portions 82 are inserted into the third and second layers are sequentially connected, resulting in a zigzag connection from the inner circumference to the outer circumference. Thus, the U-phase coil 940 has a structure in which a section connected in a zigzag pattern from the outer circumference to the inner circumference and a section connected in a zigzag pattern from the inner circumference to the outer circumference are connected, and this structure is repeated in the circumferential direction, with each unit being a single unit.

[0157] As shown in Figure 29(c), on the welded portion 88 side (solid line side shown in Figure 29(b)) of the segment coil 80, the number of pitches of the segment coils 80 inserted into the 6th layers is 7, and the number of pitches of the remaining segment coils 80 is 5 on both the welded portion 88 side (solid line side shown in Figure 29(b)) and the connecting portion 84 side (dashed line side shown in Figure 29(b)). There are two types of segment coils 80 used to construct the three-phase coil 924.

[0158] Figure 30 is a diagram illustrating the maximum voltage difference between adjacent segment coils 80 within the same slot 22s in the three-phase coil 924 shown in Figure 29, and represents the voltage difference between adjacent segment coils 80. The values ​​shown in Figure 30 are obtained by dividing the voltage difference between each adjacent segment coil 80 within the same slot 22s by (1 / 94 × Vo) [V].

[0159] As shown in Figure 30, the voltage difference between the segment coil 80 inserted in the second layer and the segment coil 80 inserted in the third layer of slot number S14 is at its maximum value (=81 / 94 × Vo). In Figure 30, the locations where the voltage difference between adjacent segment coils 80 is at its maximum value are indicated by inverted black and white text. In this embodiment, compared to Comparative Example 2, the maximum value of the voltage difference between adjacent segment coils 80 within the same slot 22s is reduced by approximately 27.2[%]{=1-(59 / 81)}.

[0160] According to this embodiment, since it has the same configuration as the aforementioned Embodiment 1, it achieves the same effects as Embodiment 1 based on that configuration.

[0161] According to this embodiment, (a) the three-phase coil 624 is Y-connected, (b) one coil section is provided between the input terminal 70 of each phase of the U-phase coil 640, V-phase coil 650, and W-phase coil 660 and the neutral point N, (c) for example, the U-phase coil 640 has two internal winding sections 640a, 640c, two external winding sections 640b, 640d, and two internal end connection sections Ji5, Ji6, and the V-phase coil 650 and W-phase coil 660 have the same configuration as the U-phase coil 640, and (d) the connection structure of the segment coil 80 in the U-phase coil 640, the connection structure of the segment coil 80 in the V-phase coil 650, and the connection structure of the segment coil 80 in the W-phase coil 660 are identical to each other. With the configuration described in (c) above, when the three-phase coil 624 is Y-connected, it becomes easier to standardize the segment coil 80 between a configuration in which one coil section is connected in series between the input terminal 70 of each phase and the neutral point N, and a configuration in which two coil sections are connected in parallel.

[0162] In this embodiment, the U-phase coil 640, V-phase coil 650, and W-phase coil 660 of the three-phase coil 624 have segment coils 80 inserted into circumferentially adjacent slots 22s in each of the two inner winding sections 640a and 640c, with the same connection order from the input terminal 70 side. Similarly, segment coils 80 inserted into circumferentially adjacent slots 22s in each of the two outer winding sections 640b and 640d have the same connection order from the input terminal 70 side. Thus, by inserting segment coils 80 with the same connection order from the input terminal 70 side for each phase into circumferentially adjacent slots 22s in each of the two inner winding sections 640a and 640c, the connection structure of the two inner winding sections 640a and 640c becomes identical. Since segment coils 80, each with the same connection sequence from the input terminal 70 side of each phase in the two outer winding sections 640b and 640d, are inserted into circumferentially adjacent slots 22s, the connection structure of the two outer winding sections 640b and 640d becomes identical. In this way, when the connection structure of the two inner winding sections 640a and 640c and the two outer winding sections 640b and 640d are identical, the complexity of the connection structure is avoided and made simpler compared to cases where it is not. For example, the bending and welding processes of the segment coil 80 become a repeating pattern, improving the workability of the winding process of the three-phase coil 624.

[0163] The above-described examples are embodiments of the present invention, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art, without departing from its spirit.

[0164] In the aforementioned embodiments 1 to 5, for example, the connection structure of the segment coil 80 within the U-phase coil 40, the connection structure of the segment coil 80 within the V-phase coil 50, and the connection structure of the segment coil 80 within the W-phase coil 60 were identical to each other. However, the present invention is not limited to this embodiment. For example, the present invention is also applicable to embodiments in which the connection structure of the segment coil 80 within the U-phase coil 40, the connection structure of the segment coil 80 within the V-phase coil 50, and the connection structure of the segment coil 80 within the W-phase coil 60 are not identical to each other. For example, the present invention may also be a three-phase coil in which any of the U-phase coils 40, 140, 240, 340, or 440 in embodiments 1 to 5 is combined with any of the V-phase coils 50, 150, 250, 350, or 450, and any of the W-phase coils 60, 160, 260, 360, or 460. When the phase coils of the connection structures in Examples 1 to 4 are combined with the phase coils of the connection structure in Example 5, preferably the phase coils of the connection structure in Example 5 and the phase coils of the connection structures in Examples 1 to 4 are oriented in opposite directions so that the connecting portions 84 and welded portions 88 of the segment coils 80 of those phase coils do not intersect each other in three dimensions.

[0165] In the above-described embodiments 1 to 5, for example, in each of the first coil section 42 and second coil section 44 of the U-phase coil 40, the first coil section 52 and second coil section 54 of the V-phase coil 50, and the first coil section 62 and second coil section 64 of the W-phase coil 60, segment coils 80 having the same connection order from the input terminal 70 side for each phase were inserted into circumferentially adjacent slots 22s. However, the present invention is not limited to this embodiment. For example, in the present invention, in the first coil section 42 and second coil section 44 of the U-phase coil 40, the first coil section 52 and second coil section 54 of the V-phase coil 50, and the first coil section 62 and second coil section 64 of the W-phase coil 60, segment coils 80 having the same connection order from the input terminal 70 side were inserted into circumferentially non-adjacent slots 22s.

[0166] In the aforementioned Embodiment 7, the outer circumferential layer connection part Ro, the intermediate layer connection part Rm, and the inner circumferential layer connection part Ri in the inner winding portions 640a and 640c were all in the same direction of rotation in the circumferential direction. However, as in the aforementioned Embodiments 2 and 3, one of the directions of the outer circumferential layer connection part Ro, the intermediate layer connection part Rm, and the inner circumferential layer connection part Ri in the inner winding portions 640a and 640c may be different from the others.

[0167] In the aforementioned Embodiment 7, the U-phase coil 640, V-phase coil 650, and W-phase coil 660 each had outer peripheral end connection portions Jo5 and Jo6, respectively. However, as in the aforementioned Embodiment 4, they may also be configured without outer peripheral end connection portions Jo5 and Jo6.

[0168] In the aforementioned Embodiment 7, the inward winding start positions C1 and D1 of the inward winding portions 640a and 650c of the V-phase coil 650 were shifted by 4 pitches relative to the inward winding start positions C1 and D1 of the inward winding portions 640a and 640c of the U-phase coil 640, and the inward winding start positions C1 and D1 of the inward winding portions 660a and 660c of the W-phase coil 660 were shifted by 8 pitches. However, the present invention is not limited to this embodiment. For example, similar to the aforementioned Embodiment 5, the inward winding start positions C1 and D1 of the U-phase coil 640, V-phase coil 650, and W-phase coil 660 may be set to predetermined positions such that the maximum voltage difference between a segment coil 80 inserted in the third layer and a segment coil 80 inserted in the fourth layer of different phases within the same slot 22s is reduced.

[0169] In the aforementioned Embodiment 7, for example, the connection structure of the segment coil 80 in the U-phase coil 640, the connection structure of the segment coil 80 in the V-phase coil 650, and the connection structure of the segment coil 80 in the W-phase coil 660 were identical to one another. However, the present invention is not limited to this embodiment. For example, the present invention is also applicable to embodiments in which the connection structures of the segment coil 80 in the U-phase coil 640, the V-phase coil 650, and the W-phase coil 660 are not identical to one another.

[0170] In the aforementioned Embodiment 7, for example, in each of the two inner winding portions 640a, 640c of the U-phase coil 640, the two inner winding portions 650a, 650c of the V-phase coil 650, and the two inner winding portions 660a, 660c of the W-phase coil 660, segment coils 80 having the same connection order from the input terminal 70 side of each phase were inserted into circumferentially adjacent slots 22s. However, the present invention is not limited to this embodiment. For example, in the present invention, in the two inner winding portions 640a, 640c of the U-phase coil 640, segment coils 80 having the same connection order from the U-phase terminal 72 side were inserted into slots 22s that were not circumferentially adjacent.

[0171] In the aforementioned embodiments 1 to 6, the inward winding start positions A1, B1, C1, and D1 of the outer layer connection portion Ro were the insertion positions of the first layer. However, the present invention is not limited to this embodiment. For example, the present invention is also applicable to embodiments where the inward winding start positions A1, B1, C1, and D1 of the outer layer connection portion Ro are the insertion positions of the second layer.

[0172] In the aforementioned embodiments 1, 2, 3, and 5, the pitch numbers of the inner circumferential end connections Ji1 and Ji2 on the connecting portion 84 side of the segment coil 80 in which both of a pair of arms 82 are inserted into the sixth layer were both 5 and 7. In the aforementioned embodiment 4, there was no segment coil 80 in which both of a pair of arms 82 are inserted into the sixth layer, and the pitch numbers of the inner circumferential end connections Ji1 and Ji2 on the welded portion 88 side of the segment coil 80 were both 5 and 7. In the aforementioned embodiment 6, the pitch number of the inner circumferential end connections Ji3 and Ji4 on the connecting portion 84 side of the segment coil 80 in which both of a pair of arms 82 are inserted into the sixth layer was 6. In the aforementioned embodiment 7, the pitch numbers of the inner circumferential end connections Ji5 and Ji6 on the connecting portion 84 side of the segment coil 80 in which both of a pair of arms 82 are inserted into the sixth layer were both 5 and 7. The present invention is not limited to these embodiments. For example, if the number of slots 22s is 48 or more, the pitch numbers of the inner circumference end connection parts Ji1, Ji2, Ji3, Ji4, Ji5, Ji6 on the connecting portion 84 side of the segment coil 80 in which both of a pair of arms 82 are inserted into the 6th layer can be both 17 and 19, or they can be 18. Alternatively, there can be no segment coil 80 in which both of a pair of arms 82 are inserted into the 6th layer, and the pitch numbers of the inner circumference end connection parts Ji1, Ji2 on the welded portion 88 side of the segment coil 80 can be both 17 and 19. [Explanation of Symbols]

[0173] 10,110,210,310,410,510,610: Rotating electric machine, 22: Stator core, 22s: Slot, 24,124,224,324,424,524,624: Three-phase coil, 30: Rotor, 40,140,240,340,440,540: U-phase coil (phase coil), 42,52,62,142,152,162,242,252,262,342,352,362,442,452,462: First coil section, 42a,44a,52a,54a,62a,64a,142a,144a,152a,154a,162a,164a,242a, 244a,252a,254a,262a,264a,342a,344a,352a,354a,362a,364a,442a,44 4a,452a,454a,462a,464a,542a,544a,552a,554a,562a,564a,640a,640c , 650a, 650c, 660a, 660c: Inner winding part, 42b, 44b, 52b, 54b, 62b, 64b, 142b, 144b, 152 b,154b,162b,164b,242b,244b,252b,254b,262b,264b,342b,344b,352b,3 54b,362b,364b,442b,444b,452b,454b,462b,464b,542b,544b,552b,554b,562b,564b,640b,640d,650b,650d,660b,660d: Outer winding section, 44,54,64,144,154,164,244,254,264,344,354,364,444,454,464: Second coil section, 50,150,250,350,450,550: V-phase coil (phase coil), 60,160,260,360,460,560: W-phase coil (phase coil), 72: U-phase terminal (Input terminal), 74: V-phase terminal (input terminal), 76: W-phase terminal (input terminal), 80: Segment coil, 82: Pair of arms, 82t: Tip, 84: Connecting part, 640: U-phase coil (phase coil, coil part), 650: V-phase coil (phase coil, coil part), 660: W-phase coil (phase coil, coil part), A1, B1, C1, D1: Inner winding start position (winding start position), A2, B2, C2, D2: Inner winding end position (end on the inner circumference side of the inner winding part), A3, B3, C3, D3: Outer winding start position (end on the inner circumference side of the outer winding part), CL: Axis, Ji1, Ji2, Ji3, Ji4, Ji5,Ji6: Inner circumferential end connection (connection part), N: Neutral point, Ri: Inner circumferential layer connection, Rm: Intermediate layer connection, Ro: Outer circumferential layer connection, SWi: Inner circumferential layer side transfer part, SWo: Outer circumferential layer side transfer part,

Claims

1. A stator core that is cylindrical in shape and extends in the axial direction and has multiple slots, A distributed winding three-phase coil is formed in which six segment coils, each having a pair of arms and a connecting portion that connects the bases of the pair of arms, are inserted into each of the plurality of slots, and one end of each pair of arms of the segment coils inserted into different slots is welded together. A rotating electric machine comprising a rotor provided on the inner circumference side of the stator core, The number of slots is six times the number of poles of the rotor. When the insertion positions of the segment coils, six of which are inserted into each of the multiple slots, are designated as the 1st layer, 2nd layer, 3rd layer, 4th layer, 5th layer, and 6th layer from the outer circumference to the inner circumference, the segment coils of the same phase in the three-phase coil are inserted three times each from the 1st to the 3rd layer on the outer circumference side of one set of slots that are adjacent in the circumferential direction among the multiple slots, and three times each from the 4th to the 6th layer on the inner circumference side of another set of slots that are shifted by one slot in the circumferential direction relative to the set of slots. Each phase coil in the three-phase coil has an inner winding portion to which the segment coils are connected from the outer circumference to the inner circumference, an outer winding portion to which the segment coils are connected from the inner circumference to the outer circumference, and a connecting portion that connects the inner end of the inner winding portion to the inner end of the outer winding portion. The inner winding portion and the outer winding portion each have an outer peripheral layer connecting portion connected in the first and second layers, respectively, so that the segment coil rotates in the circumferential direction. Regarding the connection order of the segment coils from the input terminal side of the phase coil, the connection to the segment coil inserted in the third layer and the connection to the segment coil inserted in the fourth layer are made after the connection to the outer layer in the inner winding portion. A rotating electric machine characterized by the following features.

2. The inner winding portion and the outer winding portion each include an inner circumferential layer connecting portion connected in the fifth and sixth layers so that the segment coil rotates in the circumferential direction, an intermediate layer connecting portion connected in the third and fourth layers so that the segment coil rotates in the circumferential direction, an outer circumferential layer side transfer portion connecting the end of the outer circumferential layer connecting portion and the end of the intermediate layer connecting portion, and an inner circumferential layer side transfer portion connecting the end of the inner circumferential layer connecting portion and the end of the intermediate layer connecting portion. The rotating electric machine as described in feature 1.

3. The direction in which the outer circumferential layer connection portion, the intermediate layer connection portion, and the inner circumferential layer connection portion in the inner winding portion rotate in the same direction. The rotating electric machine according to feature 2.

4. In the inner circumferential layer connection portion, the intermediate layer connection portion, and each of the inner circumferential layer connection portions, the direction in which the segment coil in the inner winding portion rotates in the circumferential direction and the direction in which the segment coil in the outer winding portion rotates in the circumferential direction are opposite to each other. The rotating electric machine according to feature 2.

5. In the outer circumferential layer connection portion and the inner circumferential layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 6 in both cases. In the intermediate layer connection portion, the number of circumferential slots on the connecting portion side and the tip portion side of the segment coil is 5 on one side and 7 on the other side. In the outer circumferential layer transfer section and the inner circumferential layer transfer section, the number of circumferential slots on either the connecting portion side or the tip portion side of the segment coil is 6. A rotating electric machine according to any one of 2 to 4, characterized by the features described above.

6. In each of the multiple slots, the winding start position of the outer layer connection portion in the inner winding portion of the phase coil is set at a predetermined position such that the maximum voltage difference between the segment coil inserted in the third layer and the segment coil inserted in the fourth layer of different phases within the same slot is minimized. A rotating electric machine according to any one of claims 1 to 4.

7. The aforementioned three-phase coil is Y-connected, Between the input terminal and the neutral point of the phase coil, two parallel-connected coil sections are provided: a first coil section and a second coil section. The connection structure of the segment coils within the phase coil is the same for each phase. A rotating electric machine according to any one of claims 1 to 4.

8. In the three-phase coil, the phase coils are such that, in the first coil section and the second coil section, the segment coils, which have the same connection order from the input terminal side of the phase coils, are inserted into circumferentially adjacent slots. The rotating electric machine according to feature 7.

9. The aforementioned three-phase coil is Y-connected, Between the input terminal and the neutral point of the phase coil, one coil section is provided. The phase coil has two inner windings, two outer windings, and two connecting parts, The connection structure of the segment coils within the phase coil is the same for each phase. A rotating electric machine according to any one of claims 1 to 4.

10. In the three-phase coil, the phase coil has two inner windings in which the segment coils, each connected in the same order from the input terminal side, are inserted into circumferentially adjacent slots, and two outer windings in which the segment coils, each connected in the same order from the input terminal side, are inserted into circumferentially adjacent slots. The rotating electric machine as described in feature 9.

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