JP3800686B2 - Concentrated winding rotary electric machine and electric vehicle using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a concentrated winding rotating electric machine, and more particularly, to a small, lightweight, highly efficient concentrated winding rotating electric machine and an electric vehicle equipped with the same.
[0002]
[Prior art]
An electric motor used for an electric vehicle such as an electric vehicle is desired to be small, light and highly efficient. For this purpose, a brushless motor using the permanent magnet type first and the reluctance second is optimal. In particular, the brushless motor described above employs a concentrated winding method in which a stator winding is wound around a stator winding magnetic pole in the field of small machines.
[0003]
This conventional example is disclosed in Japanese Patent Laid-Open No. 7-298522 (disclosed example 1).
[0004]
[Problems to be solved by the invention]
In Disclosure Example 1, the coil end portion of the stator winding is shortened by intensively winding the stator winding around the stator poles divided in the circumferential direction, and the space factor of the coil can be improved. The size of the electric motor can be reduced. However, since the inner and outer peripheral parts of the stator core are fixed by welding to fix the stator winding salient poles, the iron loss increases, and there is an iron core up to unnecessary parts, so the weight cannot be reduced, and Since the inner peripheral portion of the stator winding salient poles is not separated, there are problems such as allowing harmonic magnetic flux, generating pulsating torque, and increasing iron loss.
[0005]
An object of the present invention is to provide a compact, lightweight, high-efficiency concentrated winding rotating electric machine and an electric vehicle equipped with the same, excluding the drawbacks of the conventional examples described above.
[0006]
[Means for Solving the Problems]
The present invention suppresses the circumferential magnetic flux among the radial and circumferential magnetic fluxes existing in the salient poles at the center of the plurality of salient poles around which the three-phase stator windings are intensively wound, Rutotomoni provided a gap portion for the magnetic field in the stator teeth and alternating magnetic field, characterized in that the void portion is formed so as to narrow the radial width of the bridge portion connecting the salient poles in the circumferential direction on both sides And
[0007]
The stator core is divided at the center of the stator winding salient pole.
[0008]
According to the above configuration, by providing the stator winding salient pole of the stator core with the gap portion that suppresses the magnetic flux in the circumferential direction, at the outer peripheral portion of the stator core, the welding position of the stator core Can be set as the innermost peripheral portion , thereby minimizing the occurrence of loss and fixing with high accuracy. On the other hand , in the inner peripheral portion of the stator core, the harmonic magnetic flux circulating around the inner periphery of the salient pole can be suppressed, and thereby the suppression of the harmonic iron loss and the suppression of the pulsating magnetic flux can be achieved. Furthermore , the above effect can be maximized by adopting a configuration in which the stator core is divided at the center of the stator winding salient pole.
[0009]
With the above configuration, it is possible to provide a compact, lightweight, highly efficient concentrated winding rotating electrical machine and an electric vehicle including the same.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the present invention will be described below.
[0011]
FIG. 1 is an explanatory view of a concentrated winding electric machine according to the present invention, and FIG. 2 is a sectional view thereof.
[0012]
Here, an embodiment of a permanent magnet rotating electric machine having 10 permanent magnet poles and 9 stator winding salient poles will be described.
[0013]
In the figure, the electric motor 1 includes a stator 2 and a rotor 3, and the stator 2 includes a stator core 4 and a stator winding 5. Here, the stator core 4 is composed of a stator winding salient pole 42 and a stator yoke 41 that forms a path for the magnetic flux, and the stator winding salient pole 42 is a two-part structure constituting the stator winding 5. Large and small stator winding coils 51 shown in FIG.
52 is concentratedly wound, and is housed in the stator winding housing 47. Each winding has a configuration that does not share a magnetic path on the air gap surface. Since this concentrated winding stator structure can reduce the length of the end coil portion relative to the distributed winding structure stator used in general large machines, the size of the rotating electrical machine can be reduced. There are advantages.
[0014]
On the other hand, the rotor 3 has a configuration in which the adjacent permanent magnets 6 are arranged at substantially equal pitches and have different polarities, and has a rotor yoke 7 through which the magnetic flux of the permanent magnet passes on the inner periphery. 9 is configured to be rotatably supported by the end bracket 10 via 9. Here, a configuration in which there is no frame on the outer periphery of the stator core 4 is shown, but a frame may be used if necessary. A magnetic pole position detector PS and a position detector E for detecting the position of the permanent magnet 6 are provided on the rotor shaft 8.
[0015]
Further, U1 +, U2-, U3 + are connected to the U phase of the stator winding 5, V1 +, V2-, V3 + are connected to the V phase, and W1 +, W2-, W3 + are connected to the W phase. Here, the subscript 1 indicates the stator winding number, and + and − indicate the winding direction of the stator winding 5.
[0016]
In the present invention, the stator core 4 is divided into the same number as the stator winding 5 as shown in the figure, and each of them has two stator winding salient poles 42, a bridge portion 43, and one stator yoke portion. 41. Here, a gap 44 that suppresses the circumferential magnetic flux in the outer peripheral portion is provided in the outer peripheral portion between the divided stator cores, and a gap 45 that suppresses the circumferential magnetic flux in the inner peripheral portion is provided in the inner peripheral portion. Are provided .
[0017]
Here, a magnetic iron plate (generally constituted by a silicon steel plate) laminated in the axial direction is joined to the gap 44 for suppressing the circumferential magnetic flux in the outer peripheral portion by a welded portion 46 in the circumferential direction, and adjacent to the gap 44. Connect the split stator core. It is assumed that the laminated iron plates of the divided stator iron core 4 are integrally laminated by punching caulking or the like that is generally used at the time of punching and lamination.
[0018]
Generally, a stator winding, a stator winding salient pole around which the stator winding is wound intensively, and a stator yoke portion that constitutes a flow path of magnetic flux of the salient pole A concentrated winding electric machine composed of a stator and a rotor having a polarity at approximately equal intervals is provided with a gap provided in the stator winding salient pole of the stator core to suppress circumferential magnetic flux.
[0019]
By the configuration of providing the outer peripheral portion of the gap portion 44 suppresses the circumferential direction of the magnetic flux in the stator winding salient poles 42 of the stator core 4, the welding position of the stator core can be innermost portion Thus, it is not necessary to form a short circuit of the stator core 4 by welding. This ensures that, it is possible to suppress the occurrence of a loss to a minimum. On the other hand, by arranging the welding location on the innermost peripheral portion, the axial bulge of the inner peripheral portion of the stator core 4 can be reduced, and a highly accurate electric motor can be obtained. This leads to a reduction in noise and cogging torque. Further, with the above-described divided configuration, the magnetic flux density in each part of the stator winding magnetic pole 42 is dominated by the radial magnetic flux, and the magnetic flux becomes an alternating magnetic flux. A stator winding magnetic pole of a general concentrated winding electric machine has an elliptical magnetic field due to the presence of a radial magnetic flux and a circumferential magnetic flux. Therefore , the iron loss of the present invention, which is an alternating magnetic field for the same magnetic flux density, is reduced. Furthermore, in the present invention, the magnetic flux density is reduced by the absence of the circumferential magnetic flux, and the iron loss can be further reduced.
[0020]
Furthermore, the circumferential magnetic flux on the air gap side of the stator winding magnetic pole 42 is suppressed by the presence of the air gap 45 that suppresses the circumferential magnetic flux on the inner peripheral portion. This mainly exhibits the effect of reducing the short period harmonic magnetic flux. As a result, the effect of reducing the harmonic magnetic flux that increases the iron loss despite the low contribution to the torque generation is exhibited. Further, when used as a drive motor for an electric vehicle, the weight reduction is important because the energy of the loaded battery is limited. The weight of the electric motor can be reduced by the configuration shown in FIG.
[0021]
FIG. 3 shows another embodiment of the present invention.
[0022]
Here again, an embodiment of a permanent magnet rotating electric machine having 10 permanent magnet poles and 9 stator winding salient poles will be described.
[0023]
In the present invention, the cooling pipe 9 is arranged on the outer peripheral portion with respect to the configuration shown in FIG. As in FIG. 1, it is possible to reduce the iron loss by dividing the stator core 4. Further, the cooling pipe 9 is disposed on the outer periphery of the stator core 4, and pressure is further applied to the inside of the pipe to reduce the thermal resistance between the cooling pipe 9 and the stator core, thereby improving the cooling effect. This makes it possible to reduce the size, weight and efficiency. Further, since there is no stator core 4 on the outer peripheral portion of the cooling pipe 9, there is no magnetic flux intersecting with the cooling pipe 9, and eddy current loss (iron loss) flowing through the cooling pipe 9 can be reduced.
[0024]
FIG. 4 shows another embodiment of the present invention.
[0025]
Here, an embodiment of a permanent magnet rotating electric machine having 10 permanent magnet poles and 12 stator winding salient poles will be described.
[0026]
The cogging torque is inversely proportional to the least common multiple of the number of permanent magnet poles and the number of stator winding salient poles. Accordingly, the cogging torque in FIG. 1 is lower than that in the embodiment of FIG. In FIG. 1, when the number of poles of the permanent magnet is 10 and the number of salient stator windings is 9, a pulsation of 90 / rotation occurs. Although the number is large and the cogging torque is low, the number of poles of the permanent magnet is 10 and the appearance of the stator winding salient poles is 18 in the same manner by adding the gap 45 that suppresses the circumferential magnetic flux in the inner circumference. 90 / rotation pulsation occurs. Since the number of gaps is doubled, the cogging torque is doubled compared to the case where there is no gap 45 that suppresses the circumferential magnetic flux. On the other hand, the number of poles permanent magnet 10 of the present embodiment, although the configuration of the stator winding salient poles 12 the least common multiple of 60, the permanent magnet by the presence of the inhibiting gap portion 45 in the circumferential direction magnetic flux poles The number is 10 and the appearance of the stator winding salient poles is 24. Similarly, the pulsation is 120 / rotation. In this case, the number of pulsations of the cogging torque increases due to the presence of the gap 45 that suppresses the circumferential magnetic flux, and therefore the cogging torque can be decreased. In general, in a rotating electric machine having an odd number of pole pairs and an even number of stator salient poles, the cogging torque can be reduced by providing a gap 45 that suppresses circumferential magnetic flux.
[0027]
With this configuration, it is important that the gap 45 that suppresses the circumferential magnetic flux is longer in the radial direction than in the circumferential direction. The effect of suppressing the harmonic magnetic flux can be increased by increasing the length in the radial direction.
[0028]
The above is a description of a concentrated-winding rotating electric machine, particularly a permanent magnet rotating electric machine having a permanent magnet rotor structure, but a reluctance rotor can also exert the effects of the present invention. Moreover, not only an electric motor but also a generator may be used, and the present invention can be applied to a rotating electric machine using an outer rotation type, an inner rotation type rotor, and a claw pole type rotor. Moreover, application to not only a rotating electrical machine but also a linear motor or the like is possible.
[0029]
【The invention's effect】
According to the present invention, it is possible to provide a small, lightweight, highly efficient concentrated winding electric machine and an electric vehicle including the same.
[Brief description of the drawings]
FIG. 1 is an explanatory view of an embodiment showing a concentrated winding rotary electric machine of the present invention.
FIG. 2 is a cross-sectional view of a concentrated winding rotary electric machine according to the present invention.
FIG. 3 is a sectional view showing a second embodiment of the concentrated winding rotary electric machine according to the present invention.
FIG. 4 is a sectional view showing a third embodiment of the concentrated winding rotary electric machine according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Concentrated winding rotary electric machine, 2 ... Stator, 3 ... Rotor, 4 ... Stator iron core, 5 ... Stator winding, 6 ... Permanent magnet, 7 ... Rotor yoke, 8 ... Shaft, 41 ... Stator yoke , 42... Stator winding salient poles, 43... Bridge portion, 44 and 45... Gaps, 46.

Claims (11)

A stator having a stator core and a three-phase stator winding attached thereto;
Having a rotor disposed through a gap with respect to the stator,
The stator core is
A plurality of salient poles in which the three-phase stator windings are intensively wound;
A yoke part that constitutes a flow path of magnetic flux of the plurality of salient poles,
In the rotor, a plurality of permanent magnets are arranged at substantially equal intervals so that the polarities of adjacent ones are different from each other,
At the center of the salient pole, an air gap is provided to suppress the circumferential magnetic flux among the radial and circumferential magnetic fluxes existing in the salient pole and to make the magnetic field at the salient pole an alternating magnetic field. And
The concentrated winding electric rotating machine , wherein the gap is formed so as to narrow a radial width of a bridge portion connecting the salient poles on both sides in the circumferential direction . In the concentrated winding rotating electric machine according to claim 1,
The concentrated winding electric rotating machine, wherein the gap is provided on an outer peripheral portion of the stator core. In the concentrated winding rotating electric machine according to claim 1 or 2,
The concentrated winding electric rotating machine, wherein the gap is provided in an inner periphery of the stator core. A stator having a stator core and a three-phase stator winding attached thereto;
Having a rotor disposed through a gap with respect to the stator,
The stator core is
A plurality of magnetic plates are laminated in the axial direction,
A plurality of salient poles in which the three-phase stator windings are intensively wound;
A yoke part that constitutes a flow path of magnetic flux of the plurality of salient poles,
In the rotor, a plurality of permanent magnets are arranged at substantially equal intervals so that the polarities of adjacent ones are different from each other,
A gap is provided at the center of the salient pole,
The gap is
Among the radial and circumferential magnetic fluxes present in the salient poles, the circumferential magnetic flux is suppressed, and the magnetic field at the salient poles is used as an alternating magnetic field,
Provided on the outer peripheral portion and inner peripheral portion of the stator core;
The gap formed in the outer peripheral portion and the inner peripheral portion of the stator core is formed so as to narrow the radial width of the bridge portion connecting the salient poles on both sides in the circumferential direction.
The concentrated winding rotary electric machine characterized by the welding part for fixing the said stator core to an axial direction being provided in the innermost peripheral part of the space | gap part provided in the outer peripheral part of the said stator core. In the concentrated winding rotating electric machine according to claim 2 to 4,
The concentrated winding rotary electric machine characterized in that the innermost peripheral position of the gap provided in the outer peripheral part of the stator core is on the rotor side with respect to the inner peripheral part of the yoke part. In the concentrated winding rotating electric machine according to claim 2 or 3,
The stator core is configured by laminating a plurality of magnetic plates in the axial direction,
The concentrated winding rotary electric machine characterized by the welding part for fixing the said stator core to an axial direction in the space | gap part provided in the outer peripheral part of the said stator core. In the concentrated winding rotating electric machine according to claim 3 or 4,
The concentrated winding electric rotating machine characterized in that the gap provided in the inner peripheral portion of the stator core has a circumferential width smaller than a radial length. In the concentrated winding rotating electric machine according to any one of claims 2 to 4,
A concentrated winding rotary electric machine, wherein a cooling medium flows in a gap provided in an outer peripheral portion of the stator core. In the concentrated winding rotating electric machine according to any one of claims 2 to 4,
A cooling pipe is disposed in the gap provided in the outer periphery of the stator core,
A concentrated winding rotary electric machine characterized in that a liquid cooling medium flows through the cooling pipe. In the concentrated winding rotating electric machine according to claim 1 or 4,
The concentrated winding rotary electric machine, wherein the stator core is divided at the center of the salient pole.   An electric vehicle comprising the concentrated winding electric rotating machine according to any one of claims 1 to 10.

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