JP5063090B2 - Rotating electric machine and compressor - Google Patents

Description

  The present invention relates to a rotating electrical machine, a self-starting permanent magnet field synchronous motor, an induction motor, and a compressor.

  The advantage of the induction motor is that it has a robust structure and can be directly started by a commercial power supply, so that it can be configured at a low cost as a drive source for a constant-speed drive machine that does not require speed control. In addition, if a self-starting permanent magnet field synchronous motor is used, the drive unit can be configured at a low cost as in the case of an induction motor, and the secondary copper loss during steady-state operation is virtually eliminated. There is a merit that can greatly contribute to.

  The disadvantage is that induction torque is used at start-up, so it is almost common knowledge that the stator structure avoids the concentrated winding structure and adopts the distributed winding structure. As a result, further lower costs and higher efficiency are achieved. It is an obstacle.

  Here, although the concentrated winding structure can be configured at low cost, 6m ± 1 (m = 1, 2, 3,...) Including even order such as second order and fourth order, and fifth order and seventh order. ) Since the spatial harmonic magnetic flux mainly composed of the following is large, there is a concern about the deterioration of torque characteristics at the start due to these.

Japanese Patent Application Laid-Open No. 7-298578 and Japanese Patent Application Laid-Open No. 11-285213 disclose harmonic reduction measures for induction motors having a concentrated stator structure. These are methods to relieve even-order harmonic components such as second-order and fourth-order generated in the gap part by arranging two stators with a 90 ° pitch shift, or by rotating the rotor in the axial direction. The bars are divided into two and the pitch angles of the bars are different by 90 ° in the axial direction.

  Japanese Laid-Open Patent Publication No. 2001-157427 is a related art of a self-starting permanent magnet motor. In this technology, 4-pole concentrated winding is used, but in order to reduce abnormal torque at the start, skew is applied to the rotor and 2-pole distributed winding is used as a start-up and acceleration winding. Separate lines are provided.

JP 7-298578 A Japanese Patent Laid-Open No. 11-285213 JP 2001-157427 A

  Japanese Patent Application Laid-Open Nos. 7-298578 and 11-285213, which are prior art induction motors, use two stators and two rotors, and are disadvantageous in terms of cost. This is not practical when the assembly man-hours in production increase or dimensional management such as tolerances is taken into consideration.

  Further, in Japanese Patent Laid-Open No. 2001-157427, which is a prior art of a self-starting permanent magnet motor, the rotor secondary conductor is cylindrical, and the skew can be configured relatively easily. Since the gap becomes wider and the rated characteristics deteriorate, and it becomes difficult to make the conductor resistance sufficiently small, the synchronous pull-in torque needs to rely on the action of a separate distributed winding, etc. There is a problem.

  An object of the present invention is to provide a motor, a self-starting permanent magnet field synchronous motor, an induction motor, and a compressor that are highly efficient and can easily reduce abnormal torque at the time of starting.

  In order to achieve the above object, according to the present invention, the armature winding is composed only of concentrated windings, and the short-circuit pitch α of the short-circuit member of the squirrel-cage rotor has an electrical angle of 90 ° ≦ α ≦ 180 °. It is to provide an electric motor composed of a plurality of pairs of bars short-circuited in relation.

  According to the present invention, it is possible to provide an electric motor, a self-starting permanent magnet field synchronous motor, an induction motor, and a compressor that are highly efficient and can easily reduce abnormal torque at the time of starting.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows the shape of the end face of a cage rotor of a self-starting permanent magnet field synchronous motor according to one embodiment of the present invention, and FIG. 2 shows the self-starting permanent magnet field synchronous motor according to one embodiment of the present invention. FIG. 3 is a radial sectional view of the self-starting permanent magnet field synchronous motor according to one embodiment of the present invention (an arrow view of the BB ′ section in FIG. 2). FIG. 1 is a view taken along the line AA ′ of FIG.

  1 to 3, a self-starting permanent magnet field synchronous motor that is an object of the present invention includes a stator 1 and a rotor 2.

  The stator 1 includes a stator core 3, three slots 4 provided on the stator core 3, and teeth 5 divided into three by these slots 4.

  The armature winding 6 (consisting of a U-phase winding 6A, a V-phase winding 6B, and a W-phase winding 6C) is wound in a concentrated manner so as to surround the teeth 5, and is synchronized from the start / acceleration as an induction motor. Power is supplied from a constant frequency AC power source until constant speed operation as an electric motor.

  The rotor 2 has a plurality of starting bars 9 and a permanent magnet 11 configured to have two magnetic poles inside a rotor core 8 provided on the shaft 7. Further, the short-circuit member 10 electrically short-circuits the bar 9 at an electrical angle of 180 ° on the axial end face.

  In FIG. 4, the gap magnetic flux density of a distributed winding machine and the gap magnetic flux density measurement result of a concentrated winding machine are shown. In FIG. 4, the gap magnetic flux density distribution of the concentrated winding machine has a waveform that is positive and negative and asymmetric, and it can be seen from the spectrum that there are even harmonic magnetic flux components that do not occur in the distributed winding machine.

  FIG. 5 shows torque waveform measurement results under the influence of even-numbered harmonic magnetic flux. The torque behavior when a concentrated winding stator is simply combined with a squirrel-cage rotor is measured. As a result, when synchronization is reached after startup, a negative torque is generated, which results in hindering acceleration until synchronization.

  FIG. 6 shows a conceptual diagram of the present invention. From the result of FIG. 5, it can be said that in order to use a squirrel-cage stator in combination with a squirrel-cage rotor, it is necessary to cancel the influence of the even harmonic magnetic flux. Based on this result, in order to extract only the components without being affected by the even harmonic components, it is basically configured by short-circuiting the bar pitch α so that the electrical angle is 90 ° ≦ α ≦ 180 °. desirable.

  The reason for this will be described below. Since the wavelength of the second harmonic component is ½ of the fundamental wave, that is, the electrical angle is 180 °, if the bar pitch is arranged at 180 °, the amplitude of the second harmonic is canceled out. Similarly, although the wavelength of the fourth-order harmonic component is further shortened, it is possible to cancel the amplitude of the amplitude by setting the bar pitch to 90 ° or 180 °. Furthermore, since the wavelength of the sixth harmonic (not shown) is 60 ° in electrical angle, it can be canceled by setting it to 120 ° or 180 °. Therefore, if the bar pitch α is set to 90 ° ≦ α ≦ 180 °, it is possible to cancel from a powerful low-order even harmonic to a high-order component having a relatively small influence, which is effective by the concentrated winding stator. An induction torque can be generated.

  FIG. 7 shows the torque waveform measurement results of the present invention. This result is a measurement result of the torque waveform in the configuration described in FIG. 1 to FIG. 3, and the direct current torque is improved about three times as compared with the case where it is affected by the even harmonic magnetic flux. It can be seen that the generated negative torque component can be almost canceled out.

FIG. 8 shows the shape of the end face of a cage rotor of a self-starting permanent magnet field synchronous motor according to another embodiment of the present invention, and FIG. 9 shows the self-starting permanent magnet field according to another embodiment of the present invention. FIG. 10 is a sectional view in the axial direction of the synchronous motor. FIG. 10 is a sectional view in the radial direction of the self-starting permanent magnet field synchronous motor according to another embodiment of the present invention. Show. Note that FIG. 8 shows A-
It is an arrow view in A ', and the same code | symbol is attached | subjected to the same thing as FIGS. 1-3.

  1 to 3, the permanent magnet 11 has a four-pole configuration, six stator slots 4 are provided, and the rotor short-circuit member 10 has an electrical angle of 180 °. The bar 9 is short-circuited at a mechanical angle of 90 °. Even if comprised in this way, the effect similar to FIG. 1 can be acquired.

  FIG. 11 shows the shape of the end face of a squirrel-cage rotor of an induction motor according to another embodiment of the present invention, FIG. 12 is an axial sectional view of an induction motor according to another embodiment of the present invention, and FIG. Radial direction sectional drawing (arrow line view of a BB 'section of Drawing 12) of an induction motor concerning other examples is shown, respectively. 11 is a view taken in the direction of the arrows AA ′ in FIG. 12, and the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals.

  When configured in this way, a concentrated winding stator can be used as an induction motor, which can greatly contribute to higher efficiency and lower cost.

  FIG. 14 shows the shape of the end face of a squirrel-cage rotor of an induction motor according to another embodiment of the present invention, FIG. 15 is an axial sectional view of an induction motor according to another embodiment of the present invention, and FIG. Radial direction sectional drawing (arrow line view of the BB 'cross section of FIG. 15) of the induction motor which concerns on another Example is each shown. 14 is a view taken in the direction of the arrows AA ′ in FIG. 15, and the same components as those in FIGS. 11 to 13 are denoted by the same reference numerals.

  In the figure, the parts different from those in FIGS. 11 to 13 have a four-pole configuration with six stator slots 4 and the rotor short-circuit member 10 has an electrical angle of 180 ° and a mechanical angle of 90 °. The bar 9 is short-circuited. Even if comprised in this way, the effect similar to FIG. 11 can be acquired.

FIG. 17 shows an axial sectional view and a CC ′ arrow view of a self-starting permanent magnet field synchronous motor according to another embodiment of the present invention. In the figure, the AA ′ end face structure is the same as that in FIG.
The C ′ end face is fully short-circuited with the bar 9 by the conventional end ring 12. When configured in this way, the same effects as in FIG. 1 can be obtained, and manufacturing can be performed more simply than when both axial end faces are the same as in FIG.

  FIG. 18 shows an axial sectional view and a CC ′ arrow view of an induction motor according to another embodiment of the present invention. In the figure, the AA ′ end face structure is the same as that in FIG. 11, but the CC 9 end face completely short-circuits the bar 9 by the conventional end ring 12. When configured in this manner, the same effects as in FIG. 11 can be obtained, and the axial end faces can be manufactured more simply than in the same manner as in FIG.

  As described above, the present invention is composed of one stator and one rotor, and the self-starting permanent magnet field synchronization of the concentrated winding stator that can reduce abnormal torque at the start-up without impairing the rated characteristics. An object is to provide an electric motor, an induction motor, and a compressor using the same.

The end face shape of the cage type | mold rotor of the self-starting permanent magnet field synchronous motor which concerns on one Example of this invention. 1 is an axial sectional view of a self-starting permanent magnet field synchronous motor according to an embodiment of the present invention. 1 is a radial sectional view of a self-starting permanent magnet field synchronous motor according to an embodiment of the present invention. Gap magnetic flux density of distributed winding machine and gap magnetic flux density measurement result of concentrated winding machine. Torque waveform measurement result when affected by even harmonic magnetic flux. The conceptual diagram of this invention. The torque waveform measurement result of this invention. The end surface shape of the cage rotor of the self-starting permanent magnet field synchronous motor according to another embodiment of the present invention. The axial sectional view of the self-starting permanent magnet field synchronous motor according to another embodiment of the present invention. The radial direction sectional view of the self-starting permanent magnet field synchronous motor concerning other examples of the present invention. The end surface shape of the cage rotor of the induction motor which concerns on the other Example of this invention. The axial direction sectional drawing of the induction motor which concerns on the other Example of this invention. The radial direction sectional view of the induction motor concerning other examples of the present invention. The end surface shape of the cage rotor of the induction motor which concerns on the other Example of this invention. The axial direction sectional drawing of the induction motor which concerns on the other Example of this invention. The radial direction sectional view of the induction motor concerning other examples of the present invention. The axial sectional view and CC 'arrow line view of the self-starting permanent magnet field synchronous motor concerning other examples of the present invention. The axial direction sectional drawing and CC 'arrow line view of the induction motor which concerns on the other Example of this invention.

Explanation of symbols

1 Stator 2 Rotor 3 Stator Core 4 Slot 5 Teeth 6 Armature Winding 7 Shaft 8 Rotor Core 9 Bar (Cage Type Winding)
10 Short-circuit member 11 Permanent magnet 12 End ring

Claims (4)

A stator having armature windings wound by concentrated winding so as to surround teeth in a plurality of slots formed in the stator core;
Comprising a conductive bar in a plurality of slots provided in the vicinity of the outer peripheral portion of the rotor core, a rotor, further comprising a permanent magnet therein, the rotary electric machine having,
The conductive bars, short pitch α is 90 ° in electrical angle in the axial end face by a short circuit member is configured to short-circuit in relation to 120 ° or 180 °,
The ratio of the number of poles of the rotor to the number of slots of the stator is 2: 3;
The rotating electrical machine is activated by passing a current through the conductive bar . In claim 1,
The other end face short-circuited by the short-circuit member is configured by short-circuiting all bars. In claim 1,
The rotating electrical machine is characterized in that the number of slots of the stator is 6 m (m is an integer) . The rotary electric machine according to any one of claims 1 to 3, wherein the rotary electric machine is a compressor including a compression mechanism section that sucks in, compresses and discharges the refrigerant, and a rotary electric machine that drives the compression mechanism section. Compressor characterized by .

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