JP2001037133A - Stator and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce volumes of coil ends, without lowering the torque constant, to reduce the size, and at the same time, enable uniform distribution of fluxes generated by currents applied to windings to obtain low vibration and low-noise effects. SOLUTION: A stator comprises an annular yoke 3, a plurality of tooth parts 2 formed on the yoke 3 and a plurality of coils which are applied to the yoke by toroidal winding and connected into three-phase star-connecting or Δ-connection form. As the volumes of coil ends can be reduced, vibration and noise can be suppressed and copper loss can be minimized, motor having small size, high efficiency, low vibration and low noise having can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator in which individual coils are applied to each slot of a stator core in which a plurality of thin electromagnetic steel sheets are laminated, and the winding of each slot is formed by a stator yoke. A stator for an electric motor, wherein the coils are wound in the surrounding direction to form coils, and each coil is connected in a three-phase star or delta shape.

[0002]

2. Description of the Related Art FIG. 16 shows an external view of a typical conventional stator, and FIG. 17 shows a connection diagram of the stator. In FIG. 16, reference numeral 11 denotes a stator core 12 which is a winding. The winding method of the stator having this configuration is generally called distributed winding. As shown in FIG. 17, coils wound in each slot are connected in a three-phase star or delta shape and have a phase of 120 degrees in electrical angle. A rotating magnetic field is generated by passing the shifted current to each phase,
This rotating magnetic field generates a rotating force on the rotor inside the stator. Since the conventional distributed winding stator shown in FIG. 16 generates an ideal rotating magnetic field, the rotor can be smoothly rotated, and a low-vibration and low-noise motor can be configured.

[0003]

The stator structure according to the prior art described above is characterized in that it generates an ideal rotating magnetic field, but has the disadvantage that the volume of the coil end portion shown in FIG. . Since the current flowing through the coil end does not contribute to the generation of the torque of the motor, the copper loss generated at that portion increases and the motor efficiency decreases. Further, since the material of the coil is copper, if the volume of the coil end becomes large, the material cost becomes high. As described above, since the volume of the coil end is large in the distributed winding stator, it is difficult to reduce the size of the motor, and the material cost is high.
There is a problem such as a decrease in motor efficiency due to an increase in copper loss.

On the other hand, there is a stator having a concentrated winding structure to solve such a problem. FIG. 18 is an external view of the concentrated winding stator, and FIG. 19 is a winding diagram. As shown in FIG. 19, each of the teeth portions 2 of the stator has a concentrated winding structure.
The windings are applied in a direction surrounding the periphery of the coil, and these coils are connected in a three-phase delta and star connection. By connecting in this way, the concentrated winding stator has a smaller coil end volume as shown at 13 in FIG. 18, so that the motor can be downsized compared to the distributed winding. However, the magnetic field distribution generated by the concentrated winding structure does not become an ideal uniform rotating magnetic field unlike the distributed winding. FIG. 20 and FIG. 21 are diagrams showing the flow of magnetic flux of distributed winding and concentrated winding. FIG. 20 shows the flow of magnetic flux when a 4-pole embedded magnet type rotor is incorporated in a 4-pole distributed winding stator, and FIG. 21 shows the case where the same rotor as FIG. 20 is incorporated in a 4-pole concentrated winding stator. The flow of magnetic flux is shown. As shown in FIG. 20, the magnetic field generated by the distributed winding stator is such that the N pole and the S pole are distributed every 90 degrees, but in the concentrated winding stator, the magnetic field generated by the current flowing through the winding is 90 degrees as shown in FIG. Not uniform every time. As described above, the concentrated winding stator can have a small coil end, but has a disadvantage in that the generated magnetic field becomes non-uniform and vibration noise increases. In the concentrated winding, the angle per pole of the winding coil of the stator is smaller than the angle per pole of the rotor. For example, in the example of FIG. 21, the rotor has four poles, so that the angle is 90 degrees per pole. However, the phase per winding wound around the stator teeth is 60 degrees. As a result, the effective utilization rate of the winding becomes worse than that of the distributed winding,
There is also a disadvantage that current consumption increases.

[0005]

The present invention comprises an annular yoke portion, a plurality of teeth portions provided on the yoke portion, and a plurality of coil portions obtained by applying a toroidal winding to the yoke portion. The coil part is a stator connected in a three-phase star or delta shape. According to the present invention, a small-sized, high-efficiency, low-vibration, and low-noise motor is provided because the volume of the coil end can be reduced, vibration and noise can be reduced, and occurrence of copper loss can be minimized. It is possible to do.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an annular yoke,
A plurality of teeth provided on the yoke, and a plurality of coils formed by applying a toroidal winding to the yoke,
The plurality of coil portions are stators connected in a three-phase star or delta shape, and can reduce the volume of the coil end and suppress the occurrence of copper loss.

[0007] Further, it is preferable that the coil portion provided with the toroidal winding at the yoke portion between the teeth portions in the circumferential direction is out of phase with the adjacent coil portion.

[0008] Further, the teeth portion may have a structure in which the tips of the teeth are widened.

Further, when the outer diameter R of the stator and the axial length product thickness L <0.5R of the yoke portion are smaller than 0.5R, the occurrence of copper loss caused by flowing through the windings can be effectively reduced. .

The invention of the present application comprises a rotor, an annular yoke, a plurality of teeth provided on the yoke, and a plurality of coils formed by applying a toroidal winding to the yoke. The part is a three-phase star or delta-shaped motor, and the rotor is driven in rotation in synchronization with the rotating magnetic flux generated in the yoke part and the teeth part. The volume of the coil end can be reduced, and copper loss is reduced. Occurrence can be suppressed.

Further, the rotor may be a motor having a permanent magnet and rotating in synchronization with the rotating magnetic flux of the stator.

Further, the motor may be a motor in which a permanent magnet is embedded in the rotor, and is driven to rotate by a total torque mainly using a magnet torque and assisting a reluctance torque.

Further, the rotor may be a motor having a salient pole ratio and driven to rotate by reluctance torque.

Further, the motor may have teeth at both the inner and outer diameters of the yoke, and have an inner rotor and an outer rotor corresponding to the inner and outer teeth. .

[0015] The electric motor may be mounted such that the poles of the outer rotor and the inner rotor change at an arbitrary angle.

According to the present invention, there is provided an annular yoke portion, and a plurality of teeth provided on an inner diameter side and an outer diameter side of the yoke portion.
An inner rotor corresponding to the inner-diameter-side teeth portion, an outer rotor corresponding to the outer-diameter-side teeth portion, and a plurality of coil portions obtained by applying a toroidal winding to the yoke portion; One of the inner rotor and the outer rotor is rotated by an induction magnetic flux due to a rotating magnetic flux generated in the teeth and the yoke portion, and the other of the inner rotor and the outer rotor is rotationally driven by a synchronous magnetic flux. This makes it possible to reduce the volume of the coil end and to suppress the occurrence of copper loss.

[0017]

(Embodiment 1) FIG. 1 is a view showing a first embodiment of the present invention. In FIG. 1, 1 is a stator core, 2
Denotes a teeth portion of the stator core, 3 denotes a yoke portion, and 4 denotes a slot portion. In each slot portion, a coil in which a winding is applied in a toroidal shape is arranged and three-phase connected. 5 is
A spacer portion made of a non-magnetic material, which is provided on the yoke portion 3 in order to prevent the coil from being in contact with a coil adjacent to another portion. FIG. 2 shows a winding connection diagram of the stator shown in FIG.

As shown in FIG. 2, by winding around the yoke of the stator core, the volume of the coil end can be made very small as compared with the distributed winding. FIG. 3 is a diagram showing the flow of magnetic flux generated when a current flows through the stator of the present invention. In the stator of the present invention, FIG.
Is exactly the same as the magnetic flux distribution of the winding. Therefore, unlike the concentrated winding stator described in the conventional example, the distribution of the magnetic flux generated by the current flowing through the winding does not become non-uniform, so that even if the size is reduced, the vibration and noise can be suppressed to a very small level. It is possible.

FIG. 4 is a diagram showing current-torque characteristics when a permanent magnet rotor is incorporated in the stator of the present invention. This figure also shows the characteristics of the distributed winding stator and the concentrated winding stator when the same rotor is incorporated.

In the stator of the present invention, the distribution of magnetic flux generated by the windings is the same as that of the distributed winding, so that the torque constant is exactly the same as that of the distributed winding. The constant does not decrease. Table 1 shows the stator of the present invention and a conventional distributed winding stator.
It is the figure which showed the comparison of the stator height at the time of making the stack thickness of a concentrated winding stator the same. From Table 1, the height of the stator can be reduced to the same size as the concentrated winding. As described above, the stator of the present invention can reduce the volume of the coil end without lowering the torque constant, and at the same time can realize a motor with low vibration and noise. A great effect that can solve the problem described above can be obtained.

[0021]

[Table 1]

FIG. 5 is a diagram showing the relationship between the ratio between the outer diameter R of the stator and the thickness L, and the resistance between the wires of the winding. The figure shows a comparison between the stator of the present invention and a distributed winding stator. In the stator of the present invention, when the ratio of the outer diameter R of the stator to the thickness L, L / R is 0.5 or less, the line-to-line resistance of the winding is smaller than that of the distributed winding stator. Since the copper loss generated by flowing can be reduced, a motor that is small and has high efficiency can be realized. Thus, L /
When R is 0.5 or less, the effect of the present invention is best exhibited.

(Embodiment 2) FIG. 6 is a view showing a second embodiment of the present invention. FIG. 6 shows a permanent magnet type synchronous motor in which a permanent magnet rotor is incorporated in the stator shown in the first embodiment. By incorporating the permanent magnet rotor into the stator of the present invention, torque can be generated by the magnetic flux of the permanent magnet, so that a small-sized, high-torque, high-efficiency motor can be realized at the same time as having a small winding resistance. Further, as shown in FIG. 7, when the rotor is an embedded magnet type rotor, the reluctance torque can be effectively used in addition to the magnet torque, so that a permanent magnet synchronous motor with further reduced copper loss can be realized.

(Embodiment 3) FIG. 8 is a view showing a third embodiment of the present invention. FIG. 8 shows a synchronous reluctance motor in which a multi-flux barrier type rotor of a synchronous reluctance motor is incorporated in the stator shown in the first embodiment of the present invention. Synchronous reluctance motors do not use permanent magnets for their rotors, so they have the problem of increasing current consumption and copper loss compared to permanent magnet type synchronous motors. Since the winding resistance can be reduced without lowering the constant, the copper loss of the synchronous reluctance motor can be greatly reduced as compared with the conventional distributed winding stator.

(Embodiment 4) FIG. 9 is a view showing a fourth embodiment of the present invention. In FIG. 9, 11 is a stator core,
Reference numeral 12 denotes an inner tooth portion, 13 denotes a yoke portion, 14 denotes an inner slot portion, 17 denotes an outer tooth portion, and 18 denotes an outer slot portion. FIG. 9 shows a stator core having a structure in which the outer teeth 17 are also formed on the outer diameter side of the stator shown in the first embodiment.

In the first embodiment shown in FIG. 1, the coil 6 on the outer diameter side of the stator does not contribute to the torque generation of the motor at all, but the outer teeth 7 are also provided outside the stator as shown in FIG. Thus, since the coil on the outer diameter side of the stator can also generate a magnetic field for generating torque, it is possible to generate twice the torque with the same current.

FIG. 10 shows an example in which a surface magnet type rotor is incorporated in an inner rotor and an outer rotor with respect to the stator of the fourth embodiment shown in FIG. With such a configuration, a torque is generated in the inner rotor 20 by a current flowing through the winding in the inner slot portion 14, and a torque is generated in the outer rotor 21 by a current flowing through the outer slot portion 18.
Double torque is generated by the same current, small size, large torque,
A highly efficient motor can be obtained.

FIG. 11 shows a motor having a structure in which the boundary between the magnetic poles of the outer rotor and the inner rotor of the motor shown in FIG. Is shifted by an arbitrary angle, the cogging torque can be reduced, and a motor with lower noise can be obtained.

FIG. 12 shows a permanent magnet type synchronous motor in which an embedded magnet type rotor is incorporated in an inner rotor and a surface magnet type rotor is incorporated in an outer rotor. Thus, the motor of the present invention
It is possible to configure different types of rotors for the inner rotor 24 and the outer rotor 25. Further, the phase of the surface magnet type synchronous motor differs from that of the embedded magnet type synchronous motor when the torque generated by the same current reaches the maximum value.

Therefore, as shown in FIG. 12, by shifting the position of the boundary between the magnetic poles of the inner rotor 24 and the outer rotor 25 by an arbitrary angle β, the torque generated by each rotor can be maximized. It is possible to realize a motor with very high efficiency.

FIG. 13 shows an embodiment in which a synchronous reluctance motor is incorporated in the inner rotor and a surface magnet type rotor is incorporated in the outer rotor. As described above, in the motor of the present invention, different types of rotors can be configured for the inner rotor and the outer rotor. Further, the phase of the surface magnet type synchronous motor differs from that of the embedded magnet type synchronous motor when the torque generated by the same current reaches the maximum value. Therefore, as shown in FIG. 12, the torque generated by each rotor can be maximized by shifting the position of the boundary between the magnetic poles of the inner rotor 26 and the outer rotor 27 by an arbitrary angle β. It is possible to realize an efficient motor.

(Embodiment 5) FIG. 22 is a view showing a fifth embodiment of the present invention. The electric motor according to the fourth embodiment has a disadvantage that the motor cannot be self-started because the inner rotor and the outer rotor incorporate the synchronous motor generator rotor, and the inverter is driven by attaching a position sensor for detecting the position of the rotor. . Sensorless drive control for driving without a position sensor has also been developed, but the problem is that the control circuit becomes complicated and leads to an increase in cost. In FIG. 22, an induction motor rotor 30 is incorporated in an inner rotor, and a surface magnet synchronous motor rotor is incorporated in an outer rotor. By incorporating the induction motor rotor in the inner rotor in this way, at the time of starting, the induction motor rotor 30 rotates by generating torque.
When the motor rises to the synchronous rotation speed, the outer magnet, ie, the surface magnet synchronous electric motor generating rotor 31 is configured to generate torque, so that the motor can be started without a sensor.
Further, since the motor of the present embodiment can be driven by a general commercial power supply, it is possible to eliminate a complicated inverter circuit, and it is possible to realize a large cost reduction. Although the induction motor rotor is incorporated in the inner rotor in FIG. 22, the same effect can be obtained by incorporating the induction motor rotor in the outer rotor and the surface magnet synchronous electric motor generation rotor in the inner rotor.

FIG. 23 is a view showing another embodiment of the present embodiment. FIG. 23 shows an induction motor rotor 3 on the inner rotor.
0, an example in which the synchronous reluctance motor rotor 32 is incorporated in the outer rotor, and the same effect as that of FIG. 22 can be obtained.

(Embodiment 6) FIG. 14 is a view showing a sixth embodiment of the present invention. The sixth embodiment relates to a method of manufacturing a stator according to the present invention, in which a stator core is divided into a plurality of blocks in a circumferential direction, and winding is individually performed on a yoke portion of each divided block. Combine the blocks and make each winding a three-phase star or delta connection,
This is a method for manufacturing a stator characterized by the above. FIG. 14 shows an example in which the stator core is divided into two parts. Dividing the stator in this manner simplifies the winding process, and provides an effect of enabling a higher space factor winding than winding with an integral core. In FIG. 14, winding is individually performed on the yoke portions of the divided blocks, and the AA 'surface and the BB' surface of the divided blocks are joined together by means of welding or the like. The stator is completed by performing a three-phase star or delta connection on the wound coil. FIG. 15 is a diagram showing another example of the fifth embodiment of the present invention.
FIG. 15 shows an example in which teeth are provided on the outer diameter of the stator, and the inner rotor and the outer rotor can be incorporated therein. In the example shown in FIG.

[0035]

As is clear from the description of the above embodiment,
According to the present invention, in a stator in which individual coils are applied to respective slots of a stator core in which a plurality of thin plate-shaped electromagnetic steel sheets are stacked, winding of each slot is wound in a direction surrounding a stator yoke. By connecting each coil in a three-phase star or delta shape, it is possible to reduce the volume of the coil end without reducing the torque constant, and at the same time, the magnetic flux generated by the current flowing through the winding Since the distribution can be made uniform, effects of low vibration and low noise can be obtained. In addition, since the winding resistance can be reduced, it is possible to realize a high-efficiency motor with low copper loss, and a small-sized, low-vibration, low-noise, high-efficiency motor can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a winding connection diagram of a stator showing a first embodiment of the present invention.

FIG. 3 is a diagram showing a magnetic flux distribution by a stator according to the first embodiment of the present invention.

FIG. 4 is a diagram comparing torque constants of the stator according to the first embodiment of the present invention and a conventional stator.

FIG. 5 is a diagram comparing the line resistance of the conventional stator of the first embodiment of the present invention;

FIG. 6 is a diagram showing a second embodiment of the present invention.

FIG. 7 is a diagram showing another example of the second embodiment of the present invention.

FIG. 8 is a diagram showing a third embodiment of the present invention.

FIG. 9 is a diagram showing a fourth embodiment of the present invention.

FIG. 10 is a diagram showing another example of the fourth embodiment of the present invention.

FIG. 11 is a diagram showing another example of the fourth embodiment of the present invention.

FIG. 12 is a diagram showing another example of the fourth embodiment of the present invention.

FIG. 13 is a diagram showing another example of the fourth embodiment of the present invention.

FIG. 14 is a diagram showing a sixth embodiment of the present invention.

FIG. 15 is a diagram showing another example of the sixth embodiment of the present invention.

FIG. 16 is a diagram showing an appearance of a conventional distributed winding stator.

FIG. 17 is a diagram showing a winding diagram of a conventional distributed winding stator.

FIG. 18 is a view showing the appearance of a conventional concentrated winding stator.

FIG. 19 is a diagram showing a winding diagram of a conventional concentrated winding stator.

FIG. 20 is a diagram showing a magnetic flux distribution by a conventional distributed winding stator.

FIG. 21 is a diagram showing a magnetic flux distribution by a conventional concentrated winding stator.

FIG. 22 is a diagram showing a fifth embodiment of the present invention.

FIG. 23 is a diagram showing another example of the fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator core 2 Teeth part 3 Yoke part 4 Slot part 6 Outer coil 7 Outer tooth 8 Outer slot 9 Rotor core 10 Magnet 11 Stator core 12 Winding 13 Coil end

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 19/10 H02K 19/10 A // H02K 21/16 21/16 M (72) Inventor Yukio Honda Osaka 1006, Kadoma, Kazuma, Kadoma, Matsushita Electric Industrial Co., Ltd. (72) Inventor Masayuki Kamito 1006, Kadoma, Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. CD21 CE01 5H619 AA01 AA10 BB01 BB06 BB22 BB24 PP01 PP02 PP04 PP05 PP06 PP08 PP14 5H621 BB02 BB10 GA01 GA04 GB10 HH01 JK01

Claims (12)

[Claims] 1. An annular yoke portion, a plurality of teeth portions provided on the yoke portion, and a plurality of coil portions obtained by applying a toroidal winding to the yoke portion, wherein the plurality of coil portions are a three-phase star or Stator connected in delta. 2. The stator according to claim 1, wherein the coil portion provided with the toroidal winding at the yoke portion between the teeth portions in the circumferential direction is out of phase with the adjacent coil portion. 3. The stator according to claim 1, wherein the teeth portion has a structure in which the tips of the teeth are widened. 4. The stator according to claim 1, wherein an outer diameter R of the stator and an axial length product thickness L of the yoke portion are smaller than 0.5R. 5. A rotor, an annular yoke portion, a plurality of teeth portions provided on the yoke portion, and a plurality of coil portions obtained by applying a toroidal winding to the yoke portion, wherein the plurality of coil portions are An electric motor that is connected in a three-phase star or delta shape, and the rotor is driven to rotate in synchronization with a rotating magnetic flux generated in the yoke and the teeth. 6. The electric motor according to claim 5, wherein the rotor has a permanent magnet and rotates in synchronization with a rotating magnetic flux of the stator. 7. The electric motor according to claim 5, wherein a permanent magnet is embedded in the rotor, and the rotor is driven to rotate by total torque mainly using magnet torque and assisting reluctance torque. 8. The electric motor according to claim 5, wherein the rotor has a salient pole ratio and is driven to rotate by reluctance torque. 9. The electric motor according to claim 5, wherein the yoke has teeth on both the inner and outer diameters, and has an inner rotor and an outer rotor corresponding to the inner and outer teeth. . 10. The electric motor according to claim 9, wherein the turning points of the poles of the outer rotor and the inner rotor are shifted by an arbitrary angle. 11. An annular yoke portion, a plurality of teeth provided on the inner diameter side and the outer diameter side of the yoke portion, an inner rotor corresponding to the inner diameter side teeth, and a corresponding to the outer diameter side teeth portion. Outer rotor and a plurality of coil portions obtained by applying a toroidal winding to the yoke portion. The plurality of coil portions are connected in a three-phase star or delta shape, and are rotated by a rotating magnetic flux generated in the teeth portion and the yoke portion. An electric motor in which one of the inner rotor and the outer rotor is rotated by an induced magnetic flux, and the other of the inner rotor and the outer rotor is rotationally driven by a synchronous magnetic flux. 12. An annular yoke portion, a plurality of teeth provided on the yoke portion, and a stator body including the yoke portion are divided into a plurality of portions by the yoke portion, and the stator yoke portion is divided. In this state, a method of manufacturing a stator in which a toroidal winding is applied to the yoke portion to form a coil portion, the stator body is integrated, and the coil portions are connected in a three-phase star or delta shape.