Patent ID: 12244198

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, description will be made as to embodiments of the present invention with reference to the drawings.FIG.1is a front view showing a stator coil1according to one embodiment of present invention. The stator coil1includes a coil group10including three-phase coils of a U-phase coil11, a V-phase coil12and a W-phase coil13and includes a sheet-like coil formed in a strip shape long in one direction (left-right direction inFIG.1).

In addition, an X-direction shown inFIG.1indicates a length direction of the stator coil1. This X-direction is a direction along a circumferential direction of a stator core20when the stator coil1is mounted to the stator core20(seeFIG.2). An X1direction in the X-direction indicates one side of the length direction of the stator coil1, and an X2direction indicates the other side of the length direction of the stator coil1.FIG.1shows a Y-direction indicating a width direction of the stator coil1. This Y-direction corresponds to a direction along an axial direction (perpendicular direction to a paper surface ofFIG.2) of the stator core20when the stator coil1is mounted to the stator core20. A Y1direction in the Y-direction indicates one side in the width direction of the stator coil1, and a Y2direction indicates the other side in the width direction of the stator coil1.

Each of the U-phase coil11, the V-phase coil12and the W-phase coil13of the present embodiment includes two coils. Specifically, the U-phase coil11is configured by coils11aand11badjacent to each other in the X-direction. The V-phase coil12includes coils12aand12badjacent to each other in the X-direction The W-phase coil.13includes coils13aand13badjacent to each other in the X-direction.

The U-phase coil11, the V-phase coil12and the W-phase coil13include straight portions111,121and131, and coil end portions112,122and132, respectively.

The straight portions111,121and131are portions inserted into slots22of the stator core20. Each of the straight portions111,121and131includes two portions parallel to each other for each phase. All the straight portions111,121and131extend along the Y-direction and are arranged in parallel at a predetermined pitch along the X-direction.

The coil end portions112,122and132are portions alternately connecting, in a mountain shape in the length direction, the straight portions of each phase that are parallel in the X-direction to each other, that is, end portions of the straight portions111and111of the U-phase coil11to each other, end portions of the straight portions121and121of the V-phase coil12to each other, and end portions of the straight portions131and131of the W-phase coil13to each other. The coil end portions112,122and132protrude in a mountain shape on one side (Y1side) and the other side (Y2side) in the width direction of the stator coil1.

The coil end portions112,122and132protrude from both end faces of the stator core20in the axial direction when the stator coil1is mounted in the slots22of the stator core20. The U-phase coil11, the V-phase coil12and the W-phase coil13have the straight portions111,121and131and the mountain-shaped coil end portions112,122and132, respectively, forming a continuous wave winding coil folded into a waveform. When the continuous wave winding coil is set in the slots of the stator core, the coil does not require a common mainstream technology of dividing and molding the coil into a plurality of segments and welding coil ends after inserted into slots, and hence, to cope with thermal processing of a welding portion, for example, there is no need to use a high-purity copper material for the coil. Therefore, it is also possible to use a recycled copper material containing impurities, and it is possible to contribute to achieving of recycling of resources. In addition, the wave winding coil does not have to be welded, so that a weight of the coil can be reduced, and a weight of a rotating electric machine using this coil can be reduced. When the rotating electric machine is mounted in a hybrid car, carbon dioxide emissions can be reduced by reducing a vehicle weight, and adverse effects on global environment can be reduced.

The U-phase coil11, the V-phase coil12and the W-phase coil13at one end are provided with input terminals113a,123aand133a, respectively. The input terminals113a,123aand133aare electrically connected to two coils of each phase, that is, the coils11aand11b,12aand12b, and13aand13b, respectively.

The input terminals113a,123aand133aare portions that supply power to the U-phase coil11, the V-phase coil12and the W-phase coil13. The input terminals113a,123aand133aare connected to protrude from the end portions of the straight portions111,121and131of the U-phase coil11, the V-phase coil12and the W-phase coil13in the width direction of the stator coil1. Specifically, the input terminals113a,123aand133aare diagonally inclined from the end potions of the straight portions111,121and131arranged in endmost portions of the U-phase coil11, the V-phase coil12and the W-phase coil13on one end portion side, toward one side (X1side) of the stator coil1in the length direction, at the same inclination angle as in the coil end portions112,122and132and are bent toward one side (Y1side) of the stator coil1in the width direction, to extend parallel to the straight portions111,121and131.

The U-phase coil11, the V-phase coil12and the W-phase coil13at the other end are provided with midpoint terminals113b,123band133b, respectively. The midpoint terminals113b,123band133bare portions connecting the U-phase coil11, the V-phase coil12and the W-phase coil13, to form respective midpoints (Nu, Nv, Nw) of the U-phase coil11, the V-phase coil12and the W-phase coil13. The midpoint terminals113b,123band133bare electrically connected to two coils of each phase, that is, the coils11aand11b,12aand12b, and13aand13b, respectively. The three midpoint terminals113b,123band133bare electrically connected to a common connection plate140and are put together.

The midpoint terminals113b,123band133bare connected to protrude from the end portions of the straight portions111,121and131of the U-phase coil11, the V-phase coil12and the W-phase coil13in the width direction of the stator coil1. Specifically, the midpoint terminals113b,123band133bare diagonally inclined from the end potions of the straight portions111,121and131arranged in endmost portions of the U-phase coil11, the V-phase coil12and the W-phase coil13on the other end portion side, toward the other side (X2side) of the stator coil1in the length direction, at the same inclination angle as in the coil end portions112,122and132and are bent toward one side (Y1side) of the stator coil1in the width direction, to extend parallel to the straight portions111,121and131. As will be described later, the U-phase coil11, the V-phase coil12and the W-phase coil13are folded back from the other side (X2side) toward one side (X1side), in a middle of the stator coil1in the length direction, and hence the midpoint terminals113b,123band133bafter folded as shown inFIG.1protrude toward one side (Y1side) in the width direction of the stator coil1, in the same arrangement form as in the input terminals113a,123aand133a.

In the stator coil1, the input terminals113a,123aand133aand the midpoint terminals113b,123band133bof both the end portions of the U-phase coil11, the V-phase coil12and the W-phase coil13are arranged together on one side (X1side) of the stator coil1in the length direction shown inFIG.1. Specifically, the U-phase coil11, the V-phase coil12and the W-phase coil13are continuously formed into the waveform along the length direction of the stator coil1, folded back from the other side (X2side) to one side (X1side) in the middle, and braided. When the U-phase coil11, the V-phase coil12and the W-phase coil13are folded back, the input terminals113a,123aand133aand the midpoint terminals113b,123band133bof the respective phases are closely arranged and arranged at the same pitch as a pitch of the straight portions111,121and131of the respective phases. The U-phase coil11, the V-phase coil12and the W-phase coil13are folded back in the middle of the length direction, so that forward portions (straight portions111,121and131before folded back) and backward portions (straight portions111,121and131after folded back) of the straight portions111,121and131are laminated every phase.

Thereby, the input terminals113a,123aand133aand the midpoint terminals113b,123band133bare all orderly arranged to protrude in the same direction on one side (Y1side) of the width direction and on one side (X1side) of the length direction of the stator coil1as shown inFIG.1. The laminated straight portions111,121and131are oriented in the same direction as each other. The orientation of the straight portions111,121and131is a direction from the input terminals113a,123aand133atoward the midpoint terminals113b,123band133b. Specifically, the straight portions111,121and131of the same phase laminated on each other have the same orientation from one side (Y1side) to the other side (Y2side) or from the other side (Y2side) to one side (Y1side) in the width direction of the stator coil1.

Here, as shown inFIG.1, the input terminals113a,123aand133aand the midpoint terminals113b,123band133bof the U-phase coil11, the V-phase coil12and the W-phase coil13, respectively, are alternately arranged at a constant pitch along the length direction of the stator coil1. In the present embodiment, from one side (X1side) toward the other side (X2side) in the length direction of stator coil1, the input terminal113aof the U-phase coil11, the midpoint terminal123bof the V-phase coil12, the input terminal133aof the W-phase coil13, the midpoint terminal113bof the U-phase coil11, the input terminal123aof the V-phase coil12and the midpoint terminal133bof the W-phase coil13are arranged in order (U, Nv, W, Nu, V and Nw). Therefore, also in the straight portions111,121and131and the coil end portions112,122and132of the U-phase coil11, the V-phase coil12and the W-phase coil13, respectively, from one side (X1side) toward the other side (X2side), the forward portion of the U-phase coil11, the backward portion of the V-phase coil12, the forward portion of the W-phase coil13, the backward portion of the U-phase coil11, the forward portion of the V-phase coil12and the backward portion of the W-phase coil13are arranged in order.

In the stator coil1formed in a form of a strip-shaped sheet in this way, as shown with arrows inFIG.1, the straight portions111,121and131are oriented and alternately arranged for each phase in the orientation from one side (Y1side) to the other side (Y2side) in the width direction of the stator coil1and the orientation from the other side (Y2side) to one side (Y1side), in order from the one side (X1side) toward the other side (X2side) in the length direction of the stator coil1.

As shown inFIG.2, the stator coil1is mounted in the stator core20by inserting the straight portions111,121and131into the slots22, respectively, from a central shaft hole21side of the stator core20. Thereby, a stator2is configured. The length direction of the stator coil1of the present embodiment has a length of four circumferences in a circumferential direction of the stator core20. Therefore, the stator coil1is wound around four circumferences and mounted in the stator core20. In one circumference of the stator coil1, since the straight portions111,121and131of the forward portions and the backward portions are laminated on each other for each phase, and the stator coil1is wound around four circumferences of the stator core20, so that in each slot22, eight layers of the straight portions111,121and131are laminated and arranged in a radial direction.

FIG.3Aschematically shows the stator2in a case where the straight portions111,121and131of the stator coil1shown inFIG.1are inserted into three adjacent slots22of the stator core20.FIG.3Aschematically shows four layers among the eight layers of the straight portions111,121and131inserted into the slots22with a cross symbol in a circle and a dot symbol in a circle. The cross symbol in the circle depicted in the slot22indicates that the straight portions111,121and131of the coils in the slot22are oriented from a front side toward a back side in the perpendicular direction to the paper surface. The dot symbol in the circle depicted in the slot22indicates that the straight portions111,121and131of the coils in the slot.22are oriented from the back side toward the front side in the perpendicular direction to the paper surface.

Thus, when the stator coil1including the configuration shown inFIG.1is mounted in the stator core20, the orientations of the straight portions111,121and131of the U-phase coil11, the V-phase coil12and the W-phase coil13arranged in the adjacent slots22turn to an opposite orientation in any one of the three phases. InFIG.3A, the orientation of the straight portion121of the V-phase coil12only turns to the opposite orientation, and the orientations of the straight portions111,121and131of the U-phase coil11, the V-phase coil12and the W-phase coil13are arranged so that the orientations sequentially turn to the opposite orientation in the circumferential direction of the stator core20. Thus, when the stator coil1is mounted in the slots22of the stator core20, the orientation of the straight portion121of the V-phase coil12only differs with respect to an orientation of current to flow through the straight portions111,121and131in the slots22, and hence, as shown inFIG.3B, current flows toward the input terminal123aof the V-phase coil12, so that a rotor (not shown) disposed in the shaft hole21of the stator core20can be smoothly rotated.

FIG.4schematically shows a part of the stator2with the stator coil1mounted in the stator core20. Cross symbols in circles and dot symbols in circles are arranged in the circumferential direction of the stator core20, to schematically show four layers of the straight portions111,121and131. In each slot22, two symbols are arranged, to indicate that eight layers of the straight portions111,1.21and131are inserted in a radial direction of the stator core20. In addition, four layers of the straight portions111,121and131of the U-phase coil11, the V-phase coil12and the W-phase coil13outside in the radial direction shift by one slot in the circumferential direction from four layers inside in the radial direction.

FIG.5shows a current waveform in a case where current is supplied to the input terminals113a,123aand133aof the U-phase coil11, the V-phase coil12and the W-phase coil13in the stator2shown inFIG.4. A vertical axis indicates a magnitude of current and a horizontal axis shows an electrical angle. As shown inFIG.5, it is seen that in the stator2with the stator coil1mounted in the stator core20, current of each of the phases of the U-phase coil11, the V-phase coil12and the W-phase coil13maintains each phase at an electrical angle of 120 degrees and smoothly changes in time series.

FIGS.6A to6Fshow phases of an S-pole and an N-pole with respect to the electrical angle of the stator2shown inFIG.4. In the drawings, cross symbols in circles and dot symbols in circles depicted in the slots22indicate orientations of current in a U-phase (solid circle), a V-phase (dashed circle) and a W-phase (dashed chain line circle). The cross symbols in the circles indicate that current flowing through each of the straight portions111,121and131of the coils in the slots22is oriented from a front side toward a back side in a perpendicular direction to a paper surface. The dot symbols in the circles indicate that current flowing through each of the straight portions111,121and131of the coils in the slots22is oriented from the back side toward the front side in the perpendicular direction to the paper surface. Also, the drawings depict a position of a magnetic pole S/N generated when current is supplied to the input terminals113a,123aand133aof the U-phase coil11, the V-phase coil12and the W-phase coil13in the stator2shown inFIG.4. In each ofFIGS.6A to6F, a numeral outside the radial direction of the stator2indicates the electrical angle, and a numeral inside the radial direction indicates a phase (mechanical angle) of the S-pole. As shown inFIGS.6A to6F, it is seen that when current is supplied to the U-phase coil11, the V-phase coil12and the W-phase coil13of the stator coil1, the phase of the S-pole also smoothly moves as the electrical angle of the stator2progresses.

As described above, the stator coil1includes the coil group10including the U-phase coil11, the V-phase coil12and the W-phase coil.13, each including the plurality of straight portions111,121and131inserted into the slots22of the stator core20, the coil group being folded back in the state where the input terminals113a,123aand133aand the midpoint terminals113b,123band133bare closely arranged, so that the forward portions and backward portions of the plurality of straight portions111,121and131are laminated, wherein the input terminals113a,123aand133aand the midpoint terminals113b,123band133bof the U-phase coil11, the V-phase coil12and the W-phase coil13are alternately arranged in the length direction of the stator coil1, so that the coils of the respective phases can be optimally arranged into the slots22of the stator core20. Additionally, since the input terminals113a,123aand133aand the midpoint terminals113b,123band133bof the U-phase coil11, the V-phase coil12and the W-phase coil13are continuously arranged in the length direction of the stator coil1, all the coils of the U-phase coil11, the V-phase coil12and the W-phase coil13can be simultaneously braided, and formability into a sheet shape is satisfactory.

In addition, the stator coil is not limited to the coil formed by braiding the U-phase coil11, the V-phase coil12and the W-phase coil13as shown inFIG.1. For example, as in a stator coil1A shown inFIG.7, an input terminal123aand a midpoint terminal123bonly of a V-phase coil12may be arranged on an opposite end portion side to input terminals113aand133aand midpoint terminals113band133bof a U-phase coil11and a W-phase coil13, and the U-phase coil11, the V-phase coil12and the W-phase coil13may be simply folded back in a middle and laminated in a state where the input terminals113a,123aand133aand the midpoint terminals113b,123band133bare closely arranged.

EXPLANATION OF REFERENCE NUMERALS

1stator coilcoil group11U-phase coil12V-phase coil13W-phase coilstator core22slot111,121and131straight portion113a,123aand133ainput terminal113b,123band133bmidpoint terminalX length direction of the stator coil