WO2017169933A1

WO2017169933A1 - Stator

Info

Publication number: WO2017169933A1
Application number: PCT/JP2017/011045
Authority: WO
Inventors: 敦誉小柴; 貞一郎千葉
Original assignee: 株式会社小松製作所
Priority date: 2016-03-31
Filing date: 2017-03-17
Publication date: 2017-10-05
Also published as: JP2017184558A; DE112017001728T5; JP6692674B2

Abstract

This stator (11) comprises: a stator core (12) having a rotor housed therein and having a plurality of teeth and a plurality of slots formed alternately in a rotating direction; and a three-phase alternating-current circuit including coils each wound in a wave-winding pattern in a plurality of the slots at a predetermined pitch. The three-phase alternating-current circuit is configured by double-star connection in which a pair of coils (U1, U2) each wound in a plurality of turns on a plurality of the slots is connected in parallel. An inlet to which a power feed part of one coil (U1) is connected and an inlet to which a power feed part of the other coil (U2) is connected are arranged in different layers in the radial direction of the pair of coils (U1, U2). When Ns is the number of slots of the stator core (12) and Np is the number of poles of the rotor, the inlet of one coil (U1) and the inlet of the other coil (U2) are arranged at positions separated by 2Ns/Np+1 slots.

Description

Stator

The present invention relates to a stator.

Conventionally, it is known that a coil winding is wound around a stator (also referred to as a stator) of a rotating electrical machine (see, for example, Patent Document 1).
In wave winding, both ends of a pine needle-shaped winding segment are inserted from the insertion side of the pair of slots of the stator, and one end of the winding segment protruding from the opposite insertion side of the slot and the pair of slots The other end of another winding segment protruding from the opposite side of the slot spaced apart by a predetermined pitch in the rotation direction is welded.

JP 2014-90546 A

However, the technique described in Patent Document 1 has a problem that the number of connection points (welding points) increases as the number of turns of the coil increases.
In addition, double star connection, quad star connection, etc. may be adopted due to the freedom of winding specifications, but again the number of connections will increase, so the neutral point, the crossover of overlapping wires, etc. There is a problem that the coil end height is increased by the lead wire.

An object of the present invention is to provide a stator in which the coil end height can be lowered and the size can be reduced.

The stator according to the present invention has a rotor housed therein, a stator core having a plurality of teeth and a plurality of slots alternately formed in the rotation direction, and a plurality of slots wound in a wave-like shape at a predetermined pitch. A three-phase AC circuit having a coil, wherein the three-phase AC circuit is configured by a double star connection in which a pair of coils wound around the plurality of slots is connected in parallel, Among them, the inlet to which the power feeding part of one coil is connected and the inlet to which the power feeding part of the other coil is connected are arranged in different layers in the radial direction of the pair of coils, and the number of slots of the stator core is Ns. When the number of poles of the rotor is Np, the inlet of the one coil and the inlet of the other coil are arranged at a position 2Ns / Np + 1 slot apart. It is characterized in.

In the present invention, the predetermined pitch is preferably an Ns / Np pitch.
In the present invention, it is preferable that the one coil is wound clockwise and the other coil is wound counterclockwise.
In the present invention, each of the pair of coils is configured by connecting in series a continuous coil having two turns for one turn, and an inlet and an outlet serving as end portions of the continuous coil have diameters of the stator core. It is preferable to be arranged on the outside in the direction.

In the present invention, when the number of turns of each of the pair of coils is N, each of the coils is configured by connecting N / 2 continuous coils, and the inlet and the outlet are connected to the coil. Arranged on a pair of radiations from the center to the outer periphery, one coil of the pair of coils has an entrance at the N−2 (m−1) th from the outer periphery of the radiation of the pair of radiations. It is preferable that (m is an integer equal to or greater than 1) layers, and the exit is arranged N− (2m−1) th from the outer periphery of the other radiation layer.

In the present invention, the one coil includes an inlet disposed in the N− (2m−1) th layer from the outer periphery of one radiation, and an outlet disposed in the N−2mth layer from the outer periphery of the other radiation. Are connected by a crossover member, and the other coil is connected to the entrance arranged in the (N−2 (m−1)) th layer from the outer periphery of one radiation and N− (2m + 1) from the outer periphery of the other radiation. Are preferably connected by a crossover member.
In the present invention, the coil includes a leg portion of a pine needle coil segment in which a flat wire is bent into a pine needle shape, and is inserted into any one of the plurality of slots, and the stator core on the opposite side to the surface having the slot. It is preferable that the surfaces are welded and joined together.

According to the present invention, among the pair of coils constituting the three-phase AC circuit, the inlet of one coil and the inlet of the other coil are arranged in different layers, and the respective inlets are separated by 2 Ns / Np + 1 slots. By disposing at the position, the position of the neutral point is displaced at a position shifted in the radial direction and the circumferential direction of the stator core, so that it is possible to prevent the neutral point from overlapping vertically and to reduce the coil end height. Therefore, the size can be reduced.
Also, by arranging the entrance of one coil and the entrance of the other coil at a position 2NS / Np + 1 slots away from each other, variation in the lead length of each phase can be suppressed, thus reducing variation in phase resistance. In addition, since the two lead portions are wired in the forward direction, bending of the lead portions in the reverse direction is reduced, and processing and assembly can be facilitated.

The perspective view showing the structure of the rotary electric motor which concerns on embodiment of this invention. The perspective view showing the structure of the rotary electric motor which concerns on embodiment of this invention. The circuit diagram showing the three-phase alternating current circuit in the said embodiment. The schematic diagram showing arrangement | positioning of the inlet in which the electric power feeding part in the said embodiment is connected. The perspective view showing the continuous coil in the said embodiment. The perspective view showing the manufacturing method of the coil in the said embodiment. The perspective view showing the coil of 4 turns in the said embodiment. The perspective view showing the coil of 8 turns in the said embodiment. The schematic diagram showing the connection by the connecting wire of the 8-turn coil in the said embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are perspective views showing a stator 11 of a rotating electrical machine 10 according to the present embodiment.
[1] Schematic Description of Rotating Electric Machine 10 In FIGS. 1 and 2, the rotating electric machine 10 is, for example, three-phase (U phase, V phase, W) that drives an upper swing body of a construction machine (not shown) to rotate relative to a lower traveling body. Phase) It is configured as an 8-pole AC permanent magnet synchronous motor. The rotating electrical machine 10 includes a cylindrical stator 11 and a rotor that is rotatably accommodated inside the stator 11.

The stator 11 includes a stator core 12 configured by laminating a plurality of annular electromagnetic steel plates, and three-

phase coils

13U, 13V, and 13W formed by rectangular wires wound around the stator core 12 in a wave shape. Is provided. In the present embodiment having three phases and eight poles, 48 teeth 14 and slots 15 are alternately formed in the stator core 12 at equal intervals in the circumferential direction (the same as the rotation direction in the rotating electrical machine 10).
FIG. 3 shows a three-phase AC circuit configured by combining

coils

13U, 13V, and 13W. Coil 13U includes coils U1 and U2 that are connected in parallel, and coil 13V is connected in parallel. Coils V1 and V2 are provided, and the coil 13W includes coils W1 and W2 connected in parallel. The three-phase AC circuit employs a double star connection in which coils 13U, 13V, and 13W are connected at neutral points N1 and N2.
As shown in FIGS. 1 and 2, the neutral points of the

coils

13U, 13V, and 13W are arranged such that the first neutral point N1 is arranged on the innermost periphery and the second neutral point is second from the innermost periphery. Point N2 is arranged and arranged independently. Thereby, since the neutral points N1 and N2 do not overlap at the same inner peripheral position, the coil end is not increased. Note that the present invention is not limited to this, and the neutral points N1 and N2 may be short-circuited.

As shown in FIG. 2, in the description of the present embodiment, the numbers of the slots 15 are sequentially indicated in parentheses as (1)... (48). The same applies to the following description.
In FIG. 2, the end of the coil V1 of the coil 13V is connected to the power supply unit of the external power supply, is the outermost layer of the (48) slot 15, and the terminal of the coil V2 is also the power supply unit of the external power supply. , (13) is the second layer from the outermost periphery of the slot 15.

The positions of the power feeding units in the

coils

13U, 13V, and 13W are set to the positions shown in FIG. In the coil 13V, the position of the power feeding part LV1 in the coil V1 is the (48) th slot 15, and the position of the power feeding part LV2 in the coil V2 is the (13) th slot 15.
In the coil 13U, the position of the power feeding unit LU1 in the coil U1 is the slot (4), and the position of the power feeding unit LU2 in the coil U2 is the slot (15).

In the coil 13W, the position of the power feeding part LW1 in the coil W1 is the slot 15 of (8), and the position of the power feeding part LW2 in the coil W2 is the slot 15 of (21).
The positions of the power feeding units LU1 to LW2 in the

coils

13U, 13V, and 13W are separated by 2Ns / Np + 1 slots, where Ns is the number of slots 15 of the stator core 12 and Np is the number of poles of the rotating electrical machine 10. In this embodiment, since the number of slots 15 is 48 and the number of poles of the rotor is 8, the power feeding units LU1 to LW2 are connected every 2 × 48/8 + 1 = 13 slots.

By arranging the

coils

13U, 13V, and 13W as shown in FIG. 4, in the coil 13U, the number of crossing slots of the coil U1 is 4, and the number of the coil U2 is 9, so that a total of 13 is obtained. The number is 8 and the coil U2 is 5, for a total of 13. In the coil 13W, the number of transition slots for the coil W1 is 10, and the number of transition slots for the coil W2 is 3, for a total of 13. Therefore, since the circumferences of the

coils

13U, 13V, and 13W can be made substantially the same, variations in phase resistance can be reduced.

[2] Structure of

Coils

13U, 13V, and 13W Next, the U-phase coil 13U will be described below as a representative of the specific structures of the

coils

13U, 13V, and 13W. FIG. 5 shows a continuous coil 13 having two turns as one turn.
The continuous coil 13 is configured by combining a plurality of pine needle coil segments 131 obtained by bending a flat wire into a pine needle shape in the circumferential direction in the stator core 12. The end of the first turn coil CA and the start end of the second turn coil CB are connected by a subcoil segment 132.

The bent portion on the apex side of the pine needle of the pine needle coil segment 131 extends in the circumferential direction and shifts to the adjacent layer at the apex portion of the pine needle. Since the pine needle coil segment 131 extends obliquely in the circumferential direction, the pine needle coil segment 131 that is shifted by one pitch can extend vertically. Since the apex shifted to the adjacent layer is also shifted by one pitch, there is no interference and an intersection where the top and bottom are interchanged is made. It shifts to the layer opposite to the above at the welding position between adjacent legs. Here too, the pine needle coil segment 131 shifted by one pitch is swapped.

As shown in FIG. 6, the coils CA and CB are adjacent to each other with the pine needle coil segment 131 inserted into the slot 15 and protruding on the lower surface side which is the surface opposite to the surface having the slots of the stator core 12. It can be formed by welding the legs of the pine needle coil segment 131 together.
In the Matsuba coil segment 131, both legs are inserted at positions where the slots 15 are shifted by 6 pitches. For example, if one leg is inserted into the (1) th slot 15, the other leg is number (7). It is inserted into the slot 15.
When the number of slots 15 in the stator core 12 is Ns and the number of poles of the rotating electrical machine 10 is Np, the pitch deviation is Ns / Np pitch. In this embodiment, the number of slots is 48 and the number of poles is 8. Therefore, the pine needle coil segment 131 is inserted at a position shifted by 6 pitches.

On the other hand, the sub-coil segment 132 is inserted at a position where both legs are shifted by 5 pitches, and if one is inserted into the (1) th slot 15, the other is inserted into the (6) th slot 15. Become. By using the sub-coil segment 132, the slot 15 in which the second-round coil CB is inserted is shifted by one position from the slot 15 in which the first-round coil CA is inserted.
In addition, an S-shaped coil segment 133 is combined with the start end of the first turn pine needle coil segment 131 and the end of the second turn pine needle coil segment 131.

Hereinafter, the 8-turn coil will be described with reference to FIGS. 7, 8, and 9.
FIG. 7 shows a coil 13A having two turns and four turns. The coil 13A includes the four continuous coils 13 (hereinafter referred to as C1, C2, C3, and C4) arranged in the radial direction and connected in series as the U-phase coil U1 described in FIG. Yes.
The continuous coils C1, C2, C3, and C4 arranged concentrically from the outside have larger circumferential dimensions as the outer coils are arranged. A coil U2 similar to the coil 13A is rotated by 45 ° and combined to form an 8-turn coil as shown in FIG. The coil U1 is wound clockwise and the coil U2 is wound counterclockwise.
The inlets C1S, C2S, C3S, C4S and the outlets C1G, C2G, C3G, C4G, which are the ends of the continuous coils C1, C2, C3, C4, are arranged on a pair of radiations that go outward from the center of the coil 13A. The inlets C1S, C2S, C3S, C4S, which are the ends of the continuous coils C1, C2, C3, C4, are arranged on one radiation LL, and the outlets C1G, which are the ends of the continuous coils C1, C2, C3, C4, C2G, C3G, and C4G are disposed on the other radiation LR.
The innermost circumference is the first layer and the outermost circumference is the eighth layer.

The continuous coil C1 of the U-phase coil U1 continues from the inlet C1S of the eighth layer from the innermost circumference to the outlet C1G of the seventh layer, and the continuous coil C2 extends from the inlet C2S of the sixth layer to 5 Continue to the exit C2G of the second layer. The continuous coil C3 is continuous from the inlet C3S of the fourth layer to the outlet C3G of the third layer, and the continuous coil C4 is continuous from the inlet C4S of the second layer to the outlet C4G of the first layer.
The coil U1 connects the outlet C1G of the seventh layer and the inlet C2S of the sixth layer with a jumper, connects the outlet C2G of the fifth layer and the inlet C3S of the fourth layer with a jumper, It is formed by connecting the outlet C3G of the third layer and the inlet C4S of the second layer with a crossover.

On the other hand, the continuous coil C1 of the U-phase coil U2 is continuous from the innermost periphery from the inlet C1S of the seventh layer to the outlet C1G of the eighth layer, and the continuous coil C2 is sixth from the inlet C2S of the fifth layer. It continues to the exit C2G of the layer. The continuous coil C3 is continuous from the inlet C3S of the third layer to the outlet C3G of the fourth layer, and the continuous coil C4 is continuous from the inlet C4S of the first layer to the outlet C4G of the second layer.
The coil U2 connects the outlet C1G of the eighth layer and the inlet C2S of the fifth layer with a jumper, and connects the outlet C2G of the sixth layer and the inlet C3S of the third layer with a jumper. The fourth layer outlet C3G and the first layer inlet C4S are connected by a crossover.
If this is expressed as C1, C2,..., Inlet and outlet layers as LA1, LA2, LA3, LA4, etc., and the connecting portion as LA3-LA2, etc., the inlet of the 8-turn coil shown in FIG. The positions of the outlet and the connecting portion are as shown in Table 1 below.

According to such an 8-turn coil 13U, the inlet C1S of the coil U1 is arranged in the outermost peripheral layer LA8, and the inlet C1S of the coil U2 is arranged in the second layer LA7 from the innermost inner circumference. The outlet C4G to which the neutral point N1 of U1 is connected is arranged in the innermost layer LA1, and the outlet C4G to which the neutral point N2 of the coil U2 is connected is arranged in the second layer LA2 from the innermost circumference. be able to.
Therefore, since the neutral point N1 and the neutral point N2 are displaced in the radial direction and arranged without overlapping in the vertical direction, it is possible to prevent the coil end from becoming high.

FIG. 9 shows the arrangement of the

crossover members

134 and 135 in the 8-turn coil 13U. A feeding unit LU1 arranged in the outermost layer LA8 of the coil U1 is connected to the inlet C1S of the continuous coil C1 of the coil U1, and the continuous coil is connected between the outlet C1G of the continuous coil C1 and the inlet C2S of the continuous coil C2. A crossover member 134 is disposed between the outlet C2G of C2 and the inlet C3S of the continuous coil C3, and between the outlet C3G of the continuous coil C3 and the inlet C4S of the continuous coil C4.
On the other hand, the feeding part LU2 arranged in the second layer LA7 from the outermost periphery is connected to the inlet C1S of the continuous coil C1 of the continuous coil C1 of the coil U2, and the outlet C1G of the continuous coil C1 and the inlet C2S of the continuous coil C2 are connected. The connecting wire member 135 is disposed between the outlet C2G of the continuous coil C2 and the inlet C3S of the continuous coil C3, and between the outlet C3G of the continuous coil C3 and the inlet C4S of the continuous coil C4.
By arranging the power feeding portions LU1 to LW2 in the

coils

13U, 13V, and 13W in this way, the

crossover members

134 and 135 are arranged in the same direction, so that the

crossover members

134 and 135 overlap each other in the vertical direction. In addition, overlapping with the neutral points N1 and N2 can be prevented, and the height of the coil end can be suppressed.

Note that the coil end height can be suppressed not only in the above-described eight turns, but can be any number of turns.
For example, in the case of 4 turns, it becomes like Table 2.

For example, in the case of 6 turns, it becomes as shown in Table 3.

In case of 10 turns, it will be as shown in Table 4.

In case of 12 turns, it becomes as shown in Table 5.

In case of 14 turns, it becomes as shown in Table 6.

When these are generalized, when the number of turns of the coil 13U in which the pair of coils U1 and U2 are connected in parallel is N, each of the coils U1 and U2 is configured by connecting N / 2 continuous coils 13.
One coil U1 has inlets C1S, C2S, C3S, and C4S at the N−2 (m−1) th position from the outer periphery of one of the pair of radiations LL and LR (m is an integer of 1 or more). The exit is disposed on one radiation LL.
In addition, of the pair of coils U1 and U2, the other coil U2 is combined by rotating 45 ° in the circumferential direction with respect to one coil U1, and the inlets C1S, C2S, C3S, and C4S are rotated 45 °. Of the pair of radiations arranged, the N- (2m−1) th layer (m is an integer equal to or greater than 1) from the outer periphery of one of the radiations, and the exit is N−2 ( It is arranged in the (m-1) th layer.
Table 7 shows generalization of the connection of the

crossover members

134 and 135 of the coils U1 and U2.

One coil U1 has a cross between an inlet disposed in the N− (2m−1) th layer from the outer periphery of one radiation and an outlet disposed in the N−2mth layer from the outer periphery of the other radiation. They are connected by a line member 134.
The other coil U2 includes an inlet disposed in the N−2 (m−1) th layer from the outer periphery of one radiation, and an outlet disposed in the N− (2m + 1) th layer from the outer periphery of the other radiation. Are connected by the crossover member 135.

In the above description, the tip of the S-shaped coil segment 133 in FIG. 5, for example, the connection between the outlet C1G and the inlet C2S in FIG. 7 is described, but the present invention is not limited to this, and the connecting wire member 134 and the connecting wire member 135 are connected. May have a shape similar to that of the pine needle coil segment 131.
The pine needle coil segment 131 shifts to the outer layer by one layer while extending clockwise RT (see FIG. 6).
On the other hand, the crossover member 134 can be configured to shift to one layer on the inner circumferential side while extending seven pitches in the clockwise direction RT.
The crossover member 135 can be configured to shift to the outer layer by three layers while extending seven pitches clockwise.

According to this embodiment as described above, among the pair of coils U1 and U2 constituting the three-phase AC circuit, the inlet of one coil U1 and the inlet of the other coil U2 are arranged in different layers, By disposing the respective inlets at positions separated by 2Ns / Np + 1 slots, the positions of the neutral points N1 and N2 are disposed at positions shifted in the radial direction and the circumferential direction of the stator core 12. N2 can be prevented from overlapping in the vertical direction, the coil end height can be prevented, and downsizing can be achieved.

Further, the length of the feeding portions of the U phase, the V phase, and the W phase varies due to the entrance of the coil U1 being the slot (4) and the entrance of the coil U2 being the slot (17). Since this can be suppressed, the influence of noise is reduced.
Further, by arranging as shown in FIG. 2, the lead wire of the power feeding portion is not bent in the reverse direction, so that it is difficult to process and the insulating layer on the conductor surface of the lead wire is damaged. Can be prevented. Furthermore, since there is no bending in the reverse direction, the pine needle coil segment 131 can be easily inserted.

Since the

coils

13U, 13V, and 13W are configured with the neutral points N1 and N2 independently by double star connection, even if a potential difference due to the induced voltage occurs in the coils U1 and U2, the circulating current does not flow, and the efficiency Is good.
As shown in FIG. 9, since the continuous coil 13 is arranged from the substantially outer peripheral side, the voltage gradually decreases from the outer peripheral side. Therefore, the shared voltage adjacent in the same slot 15 is reduced.

DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine, 11 ... Stator, 12 ... Stator core, 13 ... Continuous coil, 13A ... Coil, 13U ... Coil, 13V ... Coil, 13W ... Coil, 14 ... Teeth, 15 ... Slot, 131 ... Matsuba coil segment, 132 ... Sub coil segment, 133 ... S-shaped coil segment, 134 ... Crossover wire member, 135 ... Crossover wire member, C1 ... Continuous coil, C1G ... Outlet, C1S ... Inlet, C2 ... Continuous coil, C2G ... Outlet, C2S ... Inlet, C3 ... continuous coil, C3G ... exit, C3S ... inlet, C4 ... continuous coil, C4G ... exit, C4S ... inlet, CA ... coil, CB ... coil, LA1 ... layer, LA2 ... layer, LL ... radiation, LR ... radiation, LU1 ... feeding unit, LU2 ... feeding unit, LV1 ... feeding unit, LV2 ... feeding unit, LV1 ... feeding unit, LW2 ... feeding , N1 ... first neutral point, N2 ... second neutral points, U1 ... coil, U2 ... coil, V1 ... coil, V2 ... coil, W1 ... coil, W2 ... coils.

Claims

A stator core having a plurality of teeth and a plurality of slots alternately accommodated in a rotation direction, in which a rotor is accommodated;
A three-phase AC circuit having a coil wound in a wave shape at a predetermined pitch in the plurality of slots,
The three-phase AC circuit is constituted by a double star connection in which a pair of coils wound in a plurality of turns in the plurality of slots are connected in parallel,
Of the pair of coils, the inlet to which the power feeding part of one coil is connected and the inlet to which the power feeding part of the other coil is connected are arranged in different layers in the radial direction of the pair of coils,
When the number of slots of the stator core is Ns and the number of poles of the rotor is Np, the inlet of the one coil and the inlet of the other coil are arranged at positions separated by 2Ns / Np + 1 slots. A featured stator.
The stator according to claim 1,
The stator having a predetermined pitch of Ns / Np.
The stator according to claim 1 or 2,
The stator is characterized in that the one coil is wound clockwise and the other coil is wound counterclockwise.
In the stator according to any one of claims 1 to 3,
Each coil of the pair of coils is configured by connecting in series a continuous coil having two turns as one turn,
The stator according to claim 1, wherein an inlet and an outlet serving as end portions of the continuous coil are disposed on a radially outer side of the stator core.
The stator according to claim 4, wherein
When the number of turns of each of the pair of coils is N, each coil is configured by connecting N / 2 continuous coils,
The inlet and outlet are arranged on a pair of radiations from the center of the coil toward the outer periphery,
One of the pair of coils is:
The entrance is arranged in the N−2 (m−1) th layer (m is an integer of 1 or more) from the outer periphery of one of the pair of radiations, and the exit is from the outer periphery of the other radiation layer. A stator arranged in the N- (2m-1) th.
The stator according to claim 5, wherein
The one coil has a cross between an entrance disposed in the N− (2m−1) th layer from the outer periphery of one radiation and an exit disposed in the N−2mth layer from the outer periphery of the other radiation. Connected by wire members,
In the other coil, the entrance arranged in the N−2 (m−1) th layer from the outer periphery of one radiation and the N− (2m + 1) from the outer periphery of the other radiation are connected by a crossover member. The stator is characterized by that.
The stator according to any one of claims 1 to 6,
The coil includes a leg portion of a pine needle coil segment obtained by bending a rectangular wire into a pine needle shape, and is welded to each other on the surface of the stator core opposite to the surface having the slot. And a stator that is joined.