JP4091933B2 - Permanent magnet motor - Google Patents

Description

This invention Refrigerator relates permanent magnet motors used such as a motor of the air conditioner compressor drive.

Recently, like the motor of a refrigerator or air conditioner compressor drive, control of the rotational speed easy permanent magnet motor is generally used (for example, see Patent Document 1).
Figure 19 shows a typical permanent magnet motor which is often used as the compressor drive motor.

Japanese Patent Laid-Open No. 7-336917 (page 4, FIG. 1)

  In general, in a compressor driving motor, a magnet embedding method in which a permanent magnet suitable for the requirement of high efficiency and high speed rotation is embedded in a rotor has been used.

The details of this motor will be described below with reference to this figure.
In FIG. 19, 1 is a stator, 2 is a slot, 3 is a tooth part, 4 is a winding, 5 is a rotor shaft, 6 is a magnet insertion hole, 7 is a permanent magnet, 9 is a gap, and 10 is a thin outer peripheral connection part. , 11 is a thin connecting portion between magnets, 12 is a rotor, 13 is a stator core, and 14 is a rotor core.

  The stator 1 is provided with 24 slots 2 formed at equal intervals on the inner circumference of a cylindrical stator core 13, and windings 4 are inserted and arranged in the slots 2, respectively. A pole is formed.

On the other hand, a rotor 12 is arranged with a slight gap 9 from the inner diameter of the stator core 13, and the rotor shaft 5 is fitted and fixed to the central portion of the rotor core 13 and is supported so as to be rotatable. ing.
Around the rotor shaft 5, four magnet insertion holes 6 are provided at equal intervals, and a permanent magnet 7 is inserted into the magnet insertion hole 6 from the axial direction and integrated into the magnet insertion hole 6. A rotor 12 is configured.
The permanent magnet 7 is magnetized so that the N pole and the S pole are alternated.

Next, the drive circuit and drive principle of this motor will be described with reference to FIG.
FIG. 20 shows a typical motor drive circuit often used for motor drive.
The motor drive circuit includes a DC power supply unit 15, a main circuit unit 16 and a control circuit unit 17.
The DC power supply unit 15 is connected in parallel with the main circuit and supplies power to the main circuit unit 16.

  On the other hand, the main circuit section 16 is composed of six switching elements Ua, Ub, Va, Vb, Wa, Wb and freewheeling diodes D1, D2,... D6 connected in parallel to the switching elements. Ua and Ub are connected in series, arm part Uab is connected, switching elements Va and Vb are connected in series, arm part Vab is connected, and switching elements Wa and Wb are connected in series to form arm part Wab. Three arms are formed. Furthermore, the arm portions Uab, Vab, Wab are connected in parallel to form a three-phase bridge.

In this main circuit portion, common nodes Uo, Vo, Wo of the switching elements of the three-phase arm portions Uab, Vab, Wab are connected to the corresponding motor output lines U, V, W, respectively.
These output lines U, V, W are connected to the winding 4 of each phase of the stator 1. Each phase winding is composed of a U phase, a V phase, and a W phase, and is Y-connected.

The control circuit receives the position signal of the rotor 12 and energizes the winding 4 by turning on and off each switching element of the main circuit in conjunction with the position signal. As a result, an alternating magnetic field is generated in the stator 1, and the rotor 12 is driven to rotate by a magnetic attractive force and a repulsive force acting between the alternating magnetic field and the magnetic flux generated by the permanent magnet 7.
At this time, the current-carrying width of each winding U-phase, V-phase, and W-phase is configured to be a well-known 120-degree conduction with an electrical angle of 120 degrees.

However, the conventional permanent magnet type motor configured as described above has the following problems.
In other words, the magnetic pole part of the rotor 12 is directed toward the rotation direction end of the magnetic pole part of the rotor 12 by the action of the magnetic flux A produced by the permanent magnet 7 and the magnetic flux B produced by the winding 4 as shown in FIG. The curved magnetic flux flows, and the magnetic flux concentrates on the tooth portion 3.
As a result, magnetic saturation occurs in the tooth portion 3 and the iron loss increases. Furthermore, the current value for obtaining the desired torque increases, the copper loss increases, and the efficiency decreases. This decrease becomes more remarkable when a rare earth permanent magnet is used.

Further, in the conventional rotor, since the magnetic body is arranged in the outer diameter direction of the permanent magnet 7, the fluctuation of the magnetic resistance increases depending on the positional relationship between the slot opening of the stator 1 and the rotor 12. As shown in FIG. 22, a large depression was generated in the distribution of the gap magnetic flux density in the period of the slot 2.
As a result, harmonic components are superimposed on the induced voltage waveform, resulting in a large torque ripple, which increases the vibration and noise of the motor.

  If an eccentricity such as the center of the rotor shaft 5 deviates due to manufacturing variations or the like, the gap length is unbalanced, and the diameter between the magnetic flux generated by the winding current and the magnetic pole portion of the rotor is reduced. The magnetic attraction force in the direction acted, causing vibrations with a period of the number of magnetic poles.

  The present invention solves the above-described problem, and a permanent magnet motor having low vibration, low noise, and high efficiency characteristics by appropriately arranging a plurality of slits provided in the magnetic pole portion. It is to provide.

In the permanent magnet type motor of the first invention, a rotor core provided with a permanent magnet insertion hole and a rotor shaft insertion hole, a permanent magnet inserted into the magnet insertion hole, and a rotor core on the outer peripheral side of the permanent magnet. In a permanent magnet type motor having a rotor composed of a plurality of slits provided in an inner magnetic pole portion, a plurality of slits extending from the inner peripheral side to the outer peripheral side of the rotor are provided, and the rotor iron core For all of the plurality of slits provided, the end portion located on the outer peripheral side of the slit is positioned backward from the end portion located on the inner peripheral side of the slit in the circumferential direction with respect to the rotation direction of the rotor. In this way, the slits are disposed obliquely .

In the permanent magnet type motor of the second invention, in the first invention, the outer periphery of the slit is opened.

  According to the present invention, it is possible to provide a permanent magnet motor having low vibration, low noise, and high efficiency characteristics by appropriately arranging a plurality of slits provided in the magnetic pole portion.

Embodiment 1 FIG.
It will be described in detail with reference to the accompanying drawings as an example of the permanent magnet type motor of three-phase 4-pole of the embodiment of the present invention.
FIG. 1 is a cross-sectional view of a motor showing Embodiment 1 of the present invention, FIG. 2 is a perspective view of a rotor, and FIG. 3 is an enlarged schematic view of a side surface of a laminated portion.
In the drawings, the same reference numerals indicate the same components.

  In the figure, 5 is a rotor shaft, 6 is a magnet insertion hole, 7 is a permanent magnet, 8 is a slit, 10 is an outer thin connection part, 11 is a thin connection part between magnets, and 18 is a magnetic pole part.

The configuration of the stator is the same as the conventional configuration shown in FIG. 19, which has a stator core stacked in a cylindrical axial direction and is arranged so that 24 slots are equally spaced inside. Each slot is provided with a three-phase four-pole winding.
In the hole of the stator 1, there is a rotor 12 that is rotatably supported by the rotor shaft 5 with a slight gap.

Four magnet insertion holes 6 are arranged in the rotor 12 at intervals of 90 degrees, and a rectangular parallelepiped permanent magnet 7 magnetized alternately in N and S poles is embedded in each magnet insertion hole. It is.
As shown in FIG. 1, both end portions of the magnet insertion hole 6 have a structure having an outer peripheral thin-walled connecting portion 10 and an inter-magnet thin-walled connecting portion 11 in order to prevent the formation of a short-circuit magnetic path inside the rotor. .
Further, the outer peripheral thin-walled connecting portion and the inter-magnet thin-walled connecting portion 11 have a role of connecting the magnetic pole portion 18 positioned on the outer side with respect to the permanent magnet 7 and the yoke portion 19 positioned on the inner side of the permanent magnet 7. The rotor core structure is shaped. This integral structure ensures the strength of the rotor 12 and enables high-speed rotation drive.

Furthermore, three slits 8 extending in the radial direction are formed in each magnetic pole portion.
At this time, as shown in the figure, the magnetic pole numbers existing on the outer peripheral side of the permanent magnet are the magnetic pole 1, magnetic pole 2, magnetic pole 3, magnetic pole 4, and three slits existing in the same magnetic pole, respectively, A slit, B slit, C slit When the number of poles is N (= 4) and the slit width is θs, the angle Δθ formed by the magnetic pole center and the B slit (the slit located in the middle of the three slits) satisfies the following equation: It is configured as follows.
Δθ (i) = (i−1) θs / A (1)
However, i is a magnetic pole number and A is a real number of 1 <A <N.
That is, Δθ (1) = 0 for magnetic pole 1, Δθ (2) = θs / A for magnetic pole 2, Δθ (3) = 2θs / A for magnetic pole 3, and Δθ (4) = 3θs / A for magnetic pole 4. It is comprised so that it may become.
In other words, the angle between the magnetic pole center and the B slit is increased in proportion to the magnetic pole number.

  At this time, the A slit and the C slit are arranged so that the interval is always constant with respect to the B slit even if the magnetic pole number changes.

FIG. 2 is an oblique view of the laminated rotor cores, and as shown in FIG. 2, the rotor cores are zigzag so as to form a V-shaped skew with continuous slits in the axial direction. .
FIG. 3 is a partially enlarged view of the side surface of FIG. 2, and each time one sheet is stacked, the slit 8 is arranged so that the angle is shifted by θs / A with respect to the axial direction.

Next, a method for assembling the rotor will be described with reference to FIGS.
In the figure, 20 is an upper mold, 21 is a rotor material made of an electromagnetic steel plate having a thickness of about 0.3 mm to 0.5 mm, 22 is a lower mold, 23 is a squeeze ring, 24 is a cradle, 25 is a cradle shaft, Reference numeral 26 denotes a laminated iron core.

  The manufacturing apparatus used for assembling the rotor is disposed above and below the electromagnetic steel sheet 21, and is disposed below the lower mold 22 and the upper mold 20 and the lower mold 22 used for punching the electromagnetic steel sheet 21. A cylindrical squeeze ring 23 for laminating a core punch punched from a rotor material made of an electromagnetic steel plate 21 vertically in an axial direction, a cradle 24 for horizontally receiving a laminated iron core, and the cradle 24 It comprises a cradle shaft 25 fitted and fixed at the center.

With the above configuration, the core punch made of the rotor material made of the electromagnetic steel sheet 21 punched out one by one at a constant cycle is fixed on the cradle 24 via the squeeze ring 23.
At this time, the rotor material after punching, which is the core punch, is laminated with the cradle shaft rotated in the direction determined by the magnetic pole pitch at the same period as the punching period of the upper mold 20, thereby easily skewing the slit. It becomes possible to attach.
At this time, even if the pedestal shaft 25 is rotated by the pole pitch, the magnet insertion hole 6 is not skewed and is laminated straight, so that the magnet can be easily inserted as before.

FIG. 5 is a simplified diagram showing a rotation sequence of the cradle shaft.
The point where the positive direction of the y-axis is the reference P0 and the extension line of the magnetic pole center of the rotor and the outer periphery of the pedestal intersect is defined as P1, P2, P3 and P4 as shown in the figure, and the references P0 and P1 P01 is a position where P0 and P2 are coincident, P02 is a position where P0 and P3 are coincident, P03 is a position where P0 and P3 are coincident, and P04 is a position where P0 is coincident with P4. By stacking while rotating in the order of P03 → P04 → P03 → P02 → P01..., A zigzag skew is realized.

In the permanent magnet type motor configured as described above, the distribution of the magnetic flux density becomes smooth, and the harmonic component of the induced voltage can be reduced. Therefore, a permanent magnet type motor with small torque ripple can be realized. Can do.
That is, the gap magnetic flux density distribution of the conventional motor shown in FIG. 22 where the drop of the gap magnetic flux density is large, in the motor shown in the first embodiment of the present invention, the slit position of the adjacent magnetic pole portion is relative to the magnetic pole center. Since the slits are not arranged at the same position, and the slits are also displaced in the axial direction to form a V-shaped zigzag skew, the slit positions are the same. As a result, the gap magnetic flux density drops are dispersed, and the gap magnetic flux density distribution becomes a smooth distribution with little drop as shown in FIG.

  The generated torque of the motor is proportional to the product of the gap magnetic flux density and the current flowing through the winding, and the winding current is substantially constant in the 120-degree conduction section of the rectangular wave, thus smoothing the distribution of the gap magnetic flux density. As a result, the fluctuation of the torque with respect to the rotor position is reduced, and as a result, a low-vibration, low-noise permanent magnet type motor with a small torque ripple is realized.

  Since the skew pitch of the slits is θs / A, the slits are always arranged so as to overlap with the axial direction. Thereby, the leakage of the magnetic flux in the axial direction as shown in FIG. 7 can be prevented, and the effect of the slit is not reduced.

  And by arranging three slits in the magnetic pole part, the magnetic resistance is increased, and the bending of the magnetic flux due to the armature reaction can be suppressed, and when a permanent magnet having a large magnetic force such as rare earth is used. Even if it exists, a magnetic flux concentrates on a stator teeth part, and it does not become magnetic saturation, and a highly efficient permanent magnet type motor which reduced iron loss is obtained.

  Furthermore, even when the rotor shaft is eccentric due to assembly variations, the magnetic attractive force in the radial direction acting by the magnetic flux generated by the stator winding and the magnetic pole portion of the rotor can be suppressed. Thus, a low-vibration, low-noise permanent magnet motor can be obtained.

Embodiment 2. FIG.
FIG. 8 shows a second embodiment of the present invention, which differs from the first embodiment in the following points.
That is, in the first embodiment, when the layers are stacked in the axial direction, the skew angle of the slit 8 is changed for each core punch, but in the second embodiment of the present invention, the skew angle of the slit 8 is set every two sheets. It is laminated to change. At this time, when the number of stacked layers in the axial direction is Nj and the number of poles is N, the number Nc of core punches stacked in the same direction is an integer that satisfies the following equation.
Nc ≦ Nj / (2N−1)
That is, the layers are stacked so that at least one V-shaped skew is formed.
In the rotor configured as described above, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
9 and 10 are configuration diagrams of a permanent magnet motor showing Embodiment 3 of the present invention.
FIG. 9 is a view of the rotor as seen from an oblique direction, and FIG. 10 is a partially enlarged view of the side surface of the rotor, which differs from the first embodiment in the following points.
In other words, in the first embodiment, the skew is formed so that the skew of the slit 8 forms a continuous V-shape when stacked in the axial direction, but in this embodiment, the skew is inclined. It is formed.
The rotor shown in this figure can be realized by using a dedicated mold for punching the slit and punching while shifting the mold at a predetermined pitch.

  Even in the permanent magnet type motor configured as described above, the same effect as in the first embodiment can be obtained.

Embodiment 4 FIG.
FIG. 11 shows the configuration of the permanent magnet motor showing the fourth embodiment.
In FIG. 11, the rotor shaft 5, the rotor core 14 disposed around the rotor shaft 5, and four magnet insertion holes 6 disposed at equal intervals around the rotor core 14, A permanent magnet 7 embedded in the magnet insertion hole 6 and magnetized so that N and S poles are alternately arranged, and a magnetic pole portion 18 of the rotor core 14 existing on the outer diameter side of the permanent magnet 7. And four slits 8 provided in the radial direction.

  Further, the slits 8 are arranged at irregular random intervals over the entire circumference. Such a rotor can be easily obtained by laminating silicon steel plates punched into the shape of the rotor core in a desired length in the axial direction and embedding permanent magnets in the magnet insertion holes.

  In the permanent magnet motor configured as described above, the slits are arranged at random intervals over the entire circumference of the rotor, so that vibration including the n-th resonance frequency that has been generated at a specific frequency in the past can be obtained. There is an effect that the peak value is distributed to other frequency bands, and a low-vibration permanent magnet motor that suppresses the peak value of vibration can be realized.

FIG. 12 shows the FFT analysis of the vibration component of the permanent magnet motor of the present invention. As shown in FIG. 12, slits are arranged at random intervals with respect to a conventional motor having a vibration peak at the resonance frequency. Thus, the vibration can be suppressed by smoothing the peak value of the vibration generated at the specific frequency.
Further, the radial magnetic attractive force acting between the magnetic flux generated by the winding current and the magnetic pole portion of the rotor can be reduced by the effect of the slit, and is generated at the magnetic pole cycle (in this case, four times the rotation frequency). The vibration component can be suppressed.

Embodiment 5. FIG.
FIG. 13 shows the configuration of the rotor of the permanent magnet motor according to the fifth embodiment.
In FIG. 13, the rotor shaft 5, the rotor core 14 disposed around the rotor shaft 5, four magnet insertion holes 6 disposed at equal intervals around the rotor core 14, A permanent magnet 7 embedded in the magnet insertion hole 6 and magnetized so that N and S poles are alternately arranged, and a magnetic pole portion 18 of the rotor core 14 existing on the outer diameter side of the permanent magnet 7. And three slits 8 provided so as to be inclined in the opposite direction to the rotation direction of the rotor 12.

In the permanent magnet motor configured as described above, since the slits are arranged obliquely in the direction opposite to the rotation direction, the magnetic resistance increases with respect to the path of the magnetic flux generated by the winding current. Highly efficient permanent magnet type with low iron loss because the magnetic flux due to the reaction of the child is effectively weakened and the magnetic teeth in the rotor can be prevented from being magnetically saturated due to the bending of the magnetic flux. A motor is obtained.
In addition, since the magnetic flux due to the armature reaction is weakened, the magnetic attraction force is reduced in the radial direction, and even if the rotor shaft is eccentric, the vibration component generated in the number of magnetic poles can be reduced. Thus, a permanent magnet motor with small vibration can be realized.
In addition, by making slits diagonally, the inductance change seen from the winding side becomes smooth, and the drop in the gap magnetic flux density that has been conventionally in the slot period can be reduced, and the torque ripple is reduced. Can be reduced.

Embodiment 6 FIG.
FIG. 14 is a diagram showing a rotor configuration of a permanent magnet type motor according to the sixth embodiment of the present invention, which differs from the fifth embodiment in the following points.
That is, in the fifth embodiment, the shape of the slit 8 is formed so as to be inclined in the direction opposite to the rotation direction of the rotor 12, but in the sixth embodiment, the center of the rotor shaft 5 is centered. It is characterized in that three slits 8 are provided so as to be directed radially.

In the permanent magnet type motor configured as described above, since the slits 8 are provided radially so as to face the center of the axis, the magnetic flux generated by the permanent magnet is dispersed in the radial direction, and thus is disposed on the surface. An effect similar to that obtained by radially magnetizing an arc-shaped permanent magnet can be obtained.
As a result, as shown in FIG. 15, the air gap magnetic flux density distribution has a trapezoidal wave shape, matching with control by 120-degree rectangular wave energization is improved, and a permanent magnet motor having highly efficient characteristics can be realized.

Embodiment 7 FIG.
FIG. 16 is a diagram showing a rotor configuration of the permanent magnet type motor according to the seventh embodiment of the present invention, which differs from the fifth embodiment in the following points.
That is, in the fifth embodiment, the slit 8 is formed so as to be inclined in the opposite direction to the rotation direction of the rotor 12, but in this seventh embodiment, the slit 8 is formed in the radial direction. The first slit and the second slit are divided into upper and lower parts, and the upper first slit and the lower second slit are arranged on the same straight line.
That is, it has a shape having a magnetic part at the center of the radially extending slit 8 disposed inside the rotor.

In the permanent magnet type motor configured as described above, it is difficult to pass the magnetic flux generated by the winding current due to the change in the position of the rotor by providing the upper and lower slits of the first and second slits. Since the magnetic circuit is formed so that the difference between the position and the position where it can easily pass is increased, the ratio between the maximum value and the minimum value of the winding inductance can be increased.
That is, a rotor having a large drop in magnetic resistance can be obtained, and the reluctance torque component can be increased.

  Therefore, the magnet torque due to the action of the permanent magnet and the winding current is effectively extracted, and the reluctance torque due to the electromagnet action acting between the rotor magnetic pole part and the magnetic flux generated by the winding current is added, resulting in a highly efficient permanent magnet type. A motor can be realized.

Embodiment 8 FIG.
FIG. 17 is a diagram showing a rotor configuration of the permanent magnet type motor according to the eighth embodiment of the present invention, which differs from the seventh embodiment in the following points.
That is, in the seventh embodiment, the slit 8 is formed in the upper and lower splits of the first slit and the second slit in the radial direction, and the upper first slit and the lower second slit are on the same straight line. However, in this embodiment, the slit 8 is formed in the first slit and the second slit in the upper and lower parts in the radial direction, and the upper first slit and The lower second slits are formed to be staggered.

  In the permanent magnet type motor configured as described above, the radial magnetic attractive force can be reduced.

Embodiment 9 FIG.
FIG. 18 shows a configuration diagram of the permanent magnet type motor according to the ninth embodiment of the present invention, which differs from the first embodiment in the following points.
That is, in Embodiment 1, the outer peripheral side end of the slit 8 is formed in a closed form inside the rotor core, but in this embodiment, the outer peripheral end of the slit 8 is formed. Are formed in an open form.

  In the permanent magnet type motor configured as described above, the magnetic flux generated by the winding current does not flow to the outer periphery of the slit to cause magnetic saturation, so that the current for obtaining the same torque is reduced, and further A highly efficient permanent magnet motor can be realized.

  This embodiment is not limited to the application to the first embodiment, and can be applied to any of the second to eighth embodiments.

  According to the present invention, the following operational effects can be achieved.

According to the first aspect of the present invention, the plurality of slits provided in the magnetic pole portion are disposed by being inclined obliquely in the opposite direction with respect to the rotation direction, that is, rotation on the outer peripheral side of the permanent magnet. A plurality of slits extending from the inner peripheral side to the outer peripheral side of the rotor are provided in the magnetic pole portion in the core, and all of the plurality of slits provided in the rotor core are provided on the outer peripheral side of the slit. By arranging the slit to be inclined obliquely so that the end portion positioned is positioned so as to recede in the circumferential direction with respect to the rotation direction of the rotor from the end portion located on the inner peripheral side of the slit, The change in inductance viewed from the side becomes smooth, and the drop of the gap magnetic flux density that has conventionally been in the slot period can be reduced, and the torque ripple can be reduced.

According to the second invention, by opening the outer periphery of the slit, the magnetic flux generated by the winding current does not flow to the outer periphery of the slit and causes magnetic saturation, so the current for obtaining the same torque is reduced. In addition, an even more efficient permanent magnet motor can be realized.

It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 1 of this invention. It is a perspective view of the permanent magnet type motor of FIG. It is the figure which expanded the side surface of the permanent magnet type motor of FIG. 2 partially. It is a figure which shows the assembly method of the permanent magnet type motor of FIG. It is the figure which showed the assembly sequence of FIG. 4 in detail. It is the figure which showed the space | gap magnetic flux density distribution of the permanent magnet type motor of FIG. It is the figure which showed the effect of the magnetic flux leakage prevention of the permanent magnet type motor of FIG. It is a side view which shows the structure of the permanent magnet type motor by Embodiment 2 of this invention. It is a perspective view which shows the structure of the permanent magnet type motor by Embodiment 3 of this invention. FIG. 10 is a side view of the permanent magnet motor of FIG. 9. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 4 of this invention. It is a figure which shows the vibration component of the permanent magnet type motor of FIG. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 5 of this invention. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 6 of this invention. It is a figure which shows the air gap magnetic flux density distribution of the permanent magnet type motor of FIG. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 7 of this invention. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 8 of this invention. It is sectional drawing which shows the structure of the permanent magnet type motor by Embodiment 9 of this invention. It is sectional drawing which shows the structure of the conventional permanent magnet type motor. It is a block diagram which shows the drive circuit of a permanent magnet type motor. It is the figure which showed the flow of the magnetic flux of the conventional permanent magnet type motor. It is the figure which showed the space | gap magnetic flux density of the conventional brushless DC motor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Stator, 2 slots, 3 teeth part, 4 windings, 5 rotor shaft, 6 Magnet insertion hole, 7 Permanent magnet, 8 Slit, 9 space | gap, 10 Outer periphery thin connection part, 11 Between magnet thin connection part, 12 rotations Child, 13 Stator core, 14 Rotor core, 15 DC power supply section, 16 Main circuit section, 17 Control circuit section, 18 Magnetic pole section 19 Yoke section.

Claims (2)

A rotor core provided with a permanent magnet insertion hole and a rotor shaft insertion hole, a permanent magnet inserted into the magnet insertion hole, and a plurality of slits provided in a magnetic pole portion in the rotor core on the outer peripheral side of the permanent magnet In the permanent magnet type motor including the rotor configured, a plurality of slits extending from the inner peripheral side to the outer peripheral side of the rotor are provided in the magnetic pole portion in the rotor core on the outer peripheral side of the permanent magnet , For all of the plurality of slits provided in the rotor iron core, the end portion located on the outer peripheral side of the slit is more circumferential in the rotation direction of the rotor than the end portion located on the inner peripheral side of the slit. A permanent magnet type motor characterized in that the slit is inclined obliquely so as to be positioned backward . The permanent magnet motor according to claim 1 , wherein an outer peripheral portion of the slit is opened.

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