JP5930994B2 - Rotor, compressor and refrigeration air conditioner for embedded permanent magnet electric motor - Google Patents

Description

  The present invention relates to a rotor of a permanent magnet embedded motor, a compressor, and a refrigeration air conditioner.

  As a rotor of a conventional permanent magnet embedded motor, a plurality of slits are provided between the magnet insertion hole in the rotor core and the surface of the core, thereby reducing torque ripple during operation and reducing noise. There is a rotor which aims to reduce (see, for example, Patent Document 1).

Japanese Patent No. 4964291

  However, in the rotor of the conventional permanent magnet embedded electric motor described above, the magnetic resistance between the permanent magnet and the stator is increased by providing a slit in the rotor core. Therefore, there arises a problem that the permeance of the magnet is reduced and the demagnetization resistance is deteriorated.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a rotor for an embedded permanent magnet electric motor that can prevent noise from deteriorating while reducing noise. And

  In order to achieve the above-described object, the present invention provides a permanent magnet embedded type electric motor including a core having a plurality of magnet insertion holes and a plurality of permanent magnets accommodated in each of the plurality of magnet insertion holes. In the rotor, a slit is formed between each of the magnet insertion holes and the outer surface of the core in the core, and each magnetization orientation of the permanent magnet is aligned with a magnetic pole center line. It is tilted against.

  According to the present invention, it is possible to prevent the deterioration of the demagnetization resistance while reducing the noise.

It is a figure which shows the cross section of the core of the rotor of the permanent magnet embedded type electric motor which concerns on Embodiment 1 of this invention. It is a figure which expands and shows the structure of the vicinity of one magnet insertion hole. It is a figure of the same aspect as FIG. 2 regarding the 1st example of description. It is a figure of the same aspect as FIG. 2 regarding the 2nd example of description. It is a graph which shows the relationship between a magnetization orientation angle | corner and a demagnetizing factor. It is a graph which shows the relationship between a magnetization orientation angle | corner and an induced voltage. It is a figure of the same aspect as FIG. 2 regarding the 1st aspect of Embodiment 2 of this invention. It is a figure of the same aspect as FIG. 2 regarding the 2nd aspect of this Embodiment 2. FIG. It is a figure of the same aspect as FIG. 2 regarding the 1st aspect of Embodiment 3 of this invention. It is a figure of the same aspect as FIG. 2 regarding the 2nd aspect of this Embodiment 3. FIG. It is a figure of the same aspect as FIG. 2 regarding the 1st aspect of Embodiment 4 of this invention. It is a figure of the same aspect as FIG. 2 regarding the 1st aspect of Embodiment 5 of this invention.

  Embodiments of a rotor of a permanent magnet embedded electric motor according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. Further, the left-right direction used in the description refers to a direction perpendicular to a magnetic pole center line MC described later with respect to the vicinity of each magnetic pole part.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a cross section of a rotor core of a permanent magnet embedded electric motor according to Embodiment 1 of the present invention. FIG. 2 is an enlarged view showing a configuration in the vicinity of one magnet insertion hole. The planes of FIG. 1 and FIG. 2 indicate planes having a normal axis as a rotation axis RA of the rotor described later. In addition, the hatching which shows a cross section is attached only to FIG.

  As shown in FIG. 1, a rotor 1 of an embedded permanent magnet motor includes a core 5 having a plurality of magnet insertion holes 3, a shaft 7 extending along the rotation axis RA of the core 5, and a plurality of magnet insertions. A plurality of permanent magnets 9 housed in each of the holes 3 are provided. Although not shown in the drawings, a stator (not shown) that may be in a well-known manner is provided on the radially outer side of the rotor 1 of such a permanent magnet embedded motor, with a suitable gap, and is permanent. The rotor 1 of the magnet-embedded motor is rotatably supported inside the stator.

  The core 5 is an iron core configured as a substantially cylindrical member, and has a hole through which the shaft 7 passes in the center. The plurality of magnet insertion holes 3 are formed in a portion near the outer surface 5a of the core 5 and are arranged at equal angular intervals in the circumferential direction around the rotation axis RA. In the present invention, the number of magnetic poles is not particularly limited, but the first embodiment exemplifies a six-pole mode, and the magnet insertion holes 3 are provided for each number of poles (ratio of one magnet insertion hole per pole). In other words, six magnet insertion holes 3 are formed.

  Furthermore, based on FIG. 2, the detail of the magnet insertion hole 3 and its surrounding structure are demonstrated. In the first embodiment, since the magnet insertion hole 3 and its surrounding configuration are formed point-symmetrically around the rotation axis RA, hereinafter, one magnet insertion hole 3 and its surrounding configuration will be referred to. Focus on the explanation.

  As shown in FIG. 2, the magnet insertion hole 3 and the surrounding configuration are symmetrical with respect to the corresponding magnetic pole center line MC extending in the radial direction from the rotation axis RA. The magnet insertion hole 3 is formed by an outer demarcating line 11, an inner deterministic line 13 positioned radially inward of it, and a pair of left and right end delimiting lines 15.

  The outer demarcation line 11 and the inner definite line 13 extend linearly in parallel, and both extend in a direction perpendicular to the magnetic pole center line MC. Further, the outer demarcating line 11 and the inner deterministic line 13 are separated from the magnetic pole center line MC by a predetermined distance. The pair of left and right end defining lines 15 connect the corresponding left and right ends of the outer defining line 11 and the inner defined line 13. When the permanent magnet 9 is inserted into the magnet insertion hole 3, each of the pair of end portion defining lines 15 secures a magnet end space 17 that is not filled with the end of the permanent magnet 9 in the magnet insertion hole 3. These magnet end gaps 17 are spaces that function as flux barriers. Further, the gap between each of the magnet end gaps 17 and the outer surface 5a of the core 5 is much smaller than the gap between the outer defining line 11 and the outer surface 5a of the core 5, and each of the magnet end gaps 17 and the core 5 A thin wall portion 19 is formed between the outer surface 5 a and 5.

  At least two or more slits 21 are formed between the outer demarcating line 11 and the outer surface 5 a in the core 5. The slit 21 is a gap formed in the core 5, and the torque ripple and the shaft excitation force during operation are reduced by the slit 21, and vibration and noise are reduced. Further, if there are at least two or more slits 21, such an effect can be obtained. In the embodiment shown in FIG. 2 as a specific example, eight slits 21 are provided. Two pairs of left and right slits 21 close to the magnetic pole center line MC extend along the direction in which the magnetic pole center line MC extends. A pair of left and right slits 21 at both ends close to the left and right magnet end gaps 17 extend along a circumferential direction centering on the rotation axis RA (curving direction of the outer surface 5a of the core 5). The remaining pair of slits 21 (between the slit 21 extending in the direction of the magnetic pole center line MC and the slit 21 extending in the circumferential direction) extends in the direction of the magnetic pole center line MC and the two pairs of slits 21 at the center. It is formed wider than. In other words, the eight slits 21 are formed so as to extend longer in the direction of the magnetic pole center line MC as they are closer to the magnetic pole center line MC, and to become wider as they move away from the magnetic pole center line MC.

  The permanent magnet 9 has a rectangular shape as viewed in FIG. 2, and has an outer surface 9a, an inner surface 9b, and a pair of left and right end surfaces 9c. The outer surface 9a of the permanent magnet 9 is in surface contact with the outer demarcation line 11 of the magnet insertion hole 3 in a corresponding range, the inner surface 9b is an inner definite line 13, the pair of end surfaces 9c are a pair of end demarcation lines 15, and Surface contact in the corresponding range.

  The outer surface 9a and the inner surface 9b of the permanent magnet 9 are parallel to each other, and the distance between the outer surface 9a and the inner surface 9b means the thickness of the permanent magnet 9, and the direction parallel to the magnetic pole center line MC is It is also called the thickness direction of the permanent magnet 9.

  In the first embodiment, the direction of the magnetization orientation 23 of the permanent magnet 9 is inclined with respect to the thickness direction of the permanent magnet 9 (a direction parallel to the magnetic pole center line MC). That is, the permanent magnet 9 has a magnetization orientation angle inclined by an angle θ with respect to the thickness direction of the permanent magnet 9. The permanent magnet 9 can be considered to have an equivalent magnet thickness of t / cos θ (t: actual magnet thickness) due to the effect of the inclination of the orientation of magnetization. Although the orientation itself is tilted, the orientation is parallel throughout the permanent magnet 9 (the orientation of the entire magnet is tilted in parallel).

  As the permanent magnet 9, a rare earth magnet mainly composed of Nd (neodymium), Fe (iron), and B (boron) is used. Since the rare earth magnet has a large residual magnetic flux density, a large magnet torque can be generated.

  Next, the operation of the rotor of the embedded permanent magnet electric motor according to the first embodiment will be described using an explanation example. FIGS. 3 and 4 are views of the same aspect as FIG. 2 regarding the first explanatory example and the second explanatory example, respectively.

  By embedding a permanent magnet in the rotor core, not only the magnet torque generated by the magnetic flux but also the reluctance torque generated by the saliency of the rotor can be utilized. The rotor is provided with a plurality of slits between the magnet insertion hole and the outer surface of the rotor. If there are at least two slits, the effects of vibration reduction and noise reduction can be obtained as described above. Therefore, an embodiment in which eight rotors 51 are provided as in the first explanatory example in FIG. 3 may be provided, but an embodiment in which two rotors 61 in the second explanatory example in FIG. 4 are provided.

  However, it can be considered that providing such a slit increases the magnetic resistance between the magnet and the stator (not shown), and equivalently, the gap between the rotor and the stator is enlarged. As a result, the permeance of the magnet is reduced, and a large current flows through the stator winding during operation, thereby reducing (demagnetizing) the magnetic force of the magnet.

  Generally, as shown in FIGS. 3 and 4, the orientation of the magnet is oriented in the same direction as the thickness direction of the magnet (the direction of the magnetic pole center line MC). For this reason, it is conceivable to increase the magnet permeance and improve the demagnetization resistance by increasing the magnet thickness to reduce the magnet permeance due to the slit as described above. However, increasing the magnet thickness directly leads to an increase in magnet cost due to an increase in the amount of magnet used, and it is desirable to avoid increasing the magnet thickness as much as possible.

  For such a problem, in the first embodiment, when the magnetization direction angle with respect to the magnet thickness direction is defined as the magnetization orientation angle θ, by using a magnet having the magnetization orientation angle θ larger than 0 °, The demagnetization resistance can be improved. FIG. 5 is a graph showing the relationship between the magnetization orientation angle and the demagnetization factor. Here, the demagnetization factor refers to the ratio of the induced voltage drop before and after energization when the current in the stator winding is energized. The closer the demagnetization factor is to zero, the stronger the demagnetization.

  As can be seen from FIG. 5, when the magnetization orientation angle θ is increased, the demagnetization factor changes so as to approach zero, and the demagnetization resistance is improved. That is, by setting the magnetization orientation angle θ> 0 as in the first embodiment, the magnetizing direction thickness of the magnet can be increased as compared with the conventional rotor in which the magnetization orientation angle θ = 0. As a result, the permeance of the magnet is increased and the demagnetization resistance can be improved.

  FIG. 6 shows the relationship between the magnetization orientation angle and the induced voltage. First, in order to improve the demagnetization resistance, it is desirable that the magnetization orientation angle θ is large as shown in FIG. On the other hand, as shown in FIG. 6, if the magnetization orientation angle θ is too large, the linkage flux to the stator winding (not shown) generated by the magnet is reduced, so that the induced voltage is reduced. This causes a decrease in magnet torque. For this reason, if the magnetization orientation angle θ is too large, the induced voltage is lowered and the efficiency is lowered. As shown in FIG. 6, when the magnetization orientation angle θ is 8 ° or more, the induced voltage is reduced by 1% or more. When the magnetization orientation angle θ is further increased, the rate of reduction of the induced voltage is greatly increased and the induced voltage is remarkably lowered. . Therefore, the range of the magnetization orientation angle is preferably 0 ° <θ ≦ 8 ° from the viewpoints of improving the demagnetization proof strength and suppressing the induced voltage drop. More preferably, the effect of improving the demagnetization resistance is small near the magnetization orientation angle of 0 °, and the effect of improving the demagnetization strength is increased when the magnetization orientation angle θ is 3 ° or more. It is more preferable that ° <θ ≦ 8 °.

  Further, when the permanent magnets 9 are inserted, the orientations of all the permanent magnets 9 are made to coincide with each other so as to incline toward the rotation direction of the rotor, or the orientations of all the permanent magnets 9 are changed in the counter-rotation direction of the rotor. Match to tilt to the side. By uniformly aligning the tilt sides of the orientations of all the permanent magnets 9 used in this way, the effects of the permanent magnets 9 are not unbalanced, and an increase in torque ripple can be prevented. As a result, not only vibration increase suppression and noise increase suppression by the slit 21 can be obtained, but also vibration increase suppression and noise increase can be achieved by the inclination of the magnetization orientation of the permanent magnet 9 for suppressing the demagnetization proof strength decrease by the slit 21. Suppression is obtained.

  Further, as described above, in the first embodiment, the permanent magnet 9 is a rare earth magnet mainly composed of Nd (neodymium), Fe (iron), and B (boron), and the tilted orientation 23 has a mutual orientation. , The rare earth magnet has a feature that it is easy to make a parallel orientation, and there is an advantage that the configuration of the first embodiment can be easily realized. That is, by using a rare earth magnet, a rotor of a permanent magnet embedded type electric motor having high efficiency and excellent demagnetization resistance can be configured.

  As described above, according to the first embodiment, the vibration reduction effect and the noise reduction effect due to the slit are obtained, but the magnet usage amount is not increased (depending on the increase in the actual thickness of the magnet). It is possible to prevent deterioration of the demagnetization resistance.

Embodiment 2. FIG.
Next, the rotor of the interior permanent magnet motor according to the second embodiment of the present invention will be described with reference to FIGS. 7 and FIG. 8 are diagrams of the same mode as FIG. 2 regarding the first mode and the second mode of the second embodiment, respectively. In addition, this Embodiment 2 shall be comprised similarly to the said Embodiment 1 except the part demonstrated below.

  The rotor 101 of the permanent magnet embedded electric motor according to the first aspect of the second embodiment includes a permanent magnet 109 having a chamfered portion 125a. The chamfered portion 125 a is formed at a corner of the outer surface 109 a of the permanent magnet 109. In addition, in a more detailed example, it is formed in the corner | angular part which becomes the opposite side to the side where the orientation 23 incliness among a pair of corner | angular parts of the outer surface 109a.

  The advantages of the second embodiment will be described. First, it is considered that a rotor of an embedded permanent magnet electric motor generally generates demagnetization from the vicinity of a corner portion of the outer surface of the magnet. Therefore, as in the first mode of the second embodiment, the chamfered portion 125a is formed so that a chamfered surface having the same inclination direction as the orientation 23 appears at the corner of the outer surface of the magnet. In other words, the chamfered portion 125 a is provided at the corner portion on the opposite side to the inclined side of the orientation 23. By providing the chamfered portion 125a in such a manner, partial demagnetization of the magnet can be suppressed. Further, simply tilting the orientation 23 with respect to the magnetic pole center line MC reduces the thickness in the magnetization direction at the corner of the magnet, so improvement in demagnetization resistance cannot be expected only in the corner. Furthermore, since it can be considered that the corners are equivalently short in magnet thickness, the effect of the oblique orientation is reduced. Therefore, by chamfering the corners of the magnet as shown in FIG. 7, it can be considered that the portion that is likely to be demagnetized is cut and the portion where the magnet thickness is equivalently shortened is eliminated. Will improve. In addition, when the direction in which the chamfered surface extends and the orientation are parallel, the above-described effect can be most exhibited. Therefore, preferably, the extending direction of the chamfered surface of the chamfered portion 125 a is parallel to the orientation 23.

  Moreover, you may implement this Embodiment 2 as a 2nd aspect as shown in FIG. The rotor 101 of the embedded permanent magnet electric motor of the second aspect of the second embodiment includes a permanent magnet 109 having a chamfered portion 125b that is larger than the chamfered portion 125a of the first aspect. The chamfered portion 125b has an inclination similar to that of the chamfered portion 125a for the same purpose as the chamfered portion 125a and is formed on the end surface on the same side (right side of the paper), but unlike the chamfered portion 125a, the end surface of the permanent magnet 109 Are formed so as to be configured by one surface (one straight line in FIG. 8). Preferably, the direction in which the chamfered surface of the chamfered portion 125b extends is also parallel to the orientation 23. That is, the chamfered portion 125 b is formed as a surface that bridges the outer surface 109 a and the inner surface 109 b of the permanent magnet 109. The chamfered portion 125b does not need to undergo a two-step process of adding a basic process of forming a permanent magnet into a rectangular parallelepiped shape and an additional process of chamfering a target corner. From the beginning, the target surface of the permanent magnet is inclined. It can be implemented simply by forming in the orientation.

  Also according to the second aspect of the second embodiment, the same advantages as those of the first aspect described above can be obtained. In addition, additional processing can be omitted for securing the chamfered portion, and productivity can be improved. There is also an advantage that improvement and reduction of processing costs can be achieved.

Embodiment 3 FIG.
Next, the rotor of the permanent magnet embedded electric motor according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 and FIG. 10 are diagrams of the same aspect as FIG. 2 regarding the first aspect and the second aspect of the third embodiment, respectively. In addition, this Embodiment 3 shall be comprised similarly to the said Embodiment 1 except the part demonstrated below.

  As shown in FIG. 9, the rotor 201 of the permanent magnet embedded electric motor according to the first mode of the third embodiment includes a permanent magnet 209 having a chamfered portion 125a and a chamfered portion 227a. The chamfered portion 125a is the same as the first aspect of the second embodiment described above.

  The chamfered portion 227a is formed at a corner portion of the inner side surface 209b of the permanent magnet 209. In a more detailed example, the inner side surface 209b is formed on the corner portion on the inclined side of the orientation 23, of the pair of corner portions. In other words, the chamfered portion 227a is formed so that a chamfered surface having the same inclination direction as the direction of the orientation 23 appears at the corner of the inner surface of the magnet.

  As shown in FIG. 10, the rotor 201 of the permanent magnet embedded electric motor according to the second mode of the third embodiment includes a permanent magnet 209 having a chamfered portion 125b and a chamfered portion 227b. The chamfered portion 125b is the same as the second aspect of the second embodiment described above. The chamfered portion 227b has the same orientation as the chamfered portion 227a and has the same inclination as that of the chamfered portion 227a, and is formed on the end surface on the same side (left side of the paper surface). Are formed so as to be configured by one surface (one straight line in FIG. 10). The chamfered portion 227b is formed as a surface that bridges the outer surface 209a and the inner surface 209b of the permanent magnet 209.

  The pair of chamfered portions 125a and 227a of the first mode and the pair of chamfered portions 125b and 227b of the second mode are symmetrical as the relationship between the pair of the chamfered portions 125a and 227a of the second mode. It is formed with rotational symmetry (point symmetry) with respect to the center SC. Preferably, the direction in which the chamfered surface of the chamfered portion 227a extends and the direction in which the chamfered surface of the chamfered portion 227b extend are parallel to the orientation 23.

  According to the third embodiment configured as described above, in addition to the advantages of the second embodiment, the demagnetization resistance can be further improved as compared with the case where the chamfered portion is provided only on the outer surface of the permanent magnet. Can do. This is because the magnet thickness is equivalently reduced near the corner of the inner surface of the magnet that is symmetrically located with the corner of the outer surface of the magnet that is strongly demagnetized. This is because a further improvement in the demagnetization resistance can be expected by chamfering in the same direction as the orientation. In the second mode, in particular, as in the second mode of the second embodiment, there is an advantage that the productivity can be improved and the processing cost can be reduced, and the target chamfered portions 125b and 227b are provided with the permanent magnet 209. Since it is responsible for the two opposite surfaces in the process, the advantages of improving the productivity and reducing the processing cost are extremely large effects.

  It should be noted that the third embodiment may be implemented by modifying the chamfered portions 227a and 227b only on the inner surface 209b of the permanent magnet 209.

Embodiment 4 FIG.
Next, the rotor of the permanent magnet embedded electric motor according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a diagram of the same mode as FIG. 2 regarding the fourth embodiment. In addition, this Embodiment 4 shall be comprised similarly to the said Embodiment 1 except the part demonstrated below.

  The rotor 301 of the embedded permanent magnet electric motor according to the fourth embodiment includes a permanent magnet 309 having a chamfered portion 125a and a chamfered portion 329c. The chamfered portion 125a is the same as the first aspect of the second embodiment described above.

  The chamfered portion 329 c is formed at a corner portion on the opposite side to the corner portion where the chamfered portion 125 a is provided on the outer surface 309 a of the permanent magnet 309. The chamfered portion 329c is formed so as to be symmetric with respect to the chamfered portion 125a and the magnetic pole center line MC, including the position, the size of the surface, the inclination angle, and the like.

  Also in the fourth embodiment, the demagnetization resistance can be improved as in the second embodiment. Furthermore, in the fourth embodiment, since the chamfered portion 125a and the chamfered portion 329c are formed symmetrically with respect to the magnetic pole center line MC, when the permanent magnet 209 is inserted into the core 5, the directions are reversed and reversed. Therefore, it is possible to improve productivity.

  In addition, although the illustration example of FIG. 11 demonstrated as a line symmetrical aspect regarding the chamfered part 125a, it replaced with this, the line symmetrical aspect regarding the chamfered part 125b, and the line symmetrical aspect regarding the chamfered part 227a (the chamfered part is not provided on the outer surface). Alternatively, it can also be implemented as a line-symmetric aspect (no chamfered portion on the outer surface) with respect to the chamfered portion 227b.

Embodiment 5 FIG.
Next, the rotor of the interior permanent magnet motor according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 12 is a diagram of the same mode as FIG. In addition, this Embodiment 5 shall be comprised similarly to the said Embodiment 1 except the part demonstrated below.

  A rotor 401 of an embedded permanent magnet electric motor according to the fifth embodiment includes a permanent magnet 409 having a chamfered portion 125a, a chamfered portion 227a, a chamfered portion 329c, and a chamfered portion 431d. The chamfered portion 125a is the same as the first aspect of the second embodiment described above. The chamfered portion 227a is the same as the first aspect of the third embodiment described above. The chamfered portion 329c is the same as that in the fourth embodiment described above. The relationship between the chamfered portion 431 d and the chamfered portion 329 c is formed in rotational symmetry (point symmetry) with respect to the symmetry center SC that is the center of the permanent magnet 409 in the thickness direction and width direction.

  From the above, the four chamfered portions 125a, 227a, 329c, and 431d formed at all four corners of the permanent magnet 409 having a rectangular cross section are in the thickness direction of the permanent magnet 409 (vertical direction / inside / outside direction). It is formed in rotational symmetry (point symmetry) with respect to a symmetry center SC that is the center in the width direction (left-right direction). In other words, the four chamfered portions 125a, 227a, 329c, and 431d are bilaterally symmetric and vertically symmetric.

  According to the fifth embodiment, the same advantages as those of the first to fourth embodiments can be obtained. Furthermore, in the fifth embodiment, the permanent magnets 409 themselves are rotationally symmetric, bilaterally symmetric, and vertically symmetric because of the relationship between the four chamfered portions, and the permanent magnets are inserted from any direction. There is also an advantage that workability when inserting a magnet into the rotor is extremely high.

Embodiment 6 FIG.
The present invention can also be implemented as a compressor. That is, the compressor includes at least a compression element and an electric motor that uses the rotor of the permanent magnet embedded motor according to any one of Embodiments 1 to 5 described above as an electric motor that drives the compression element. A specific example is a cylinder rotary compressor, but the type of the compressor according to the present invention is not limited to the rotary compressor, and the configuration of the compression element is driven by an electric motor. There is no particular limitation as long as it is an embodiment.

Embodiment 7 FIG.
The present invention can also be implemented as a refrigeration air conditioner including the above-described compressor of the sixth embodiment as a component of the refrigeration circuit. Since the electric motor mounted on the compressor for the refrigerating and air-conditioning apparatus is used at a high temperature, it is easy to demagnetize due to a decrease in the coercive force of the permanent magnet. By applying the rotor of the type motor, a compressor having excellent demagnetization resistance during operation can be provided. In addition, the structure of components other than the compressor in the refrigeration circuit of the refrigeration air conditioner is not particularly limited.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory.

  1, 101, 201, 301, 401 Permanent magnet embedded motor rotor, 3 magnet insertion hole, 5 core, 5a outer surface, 9, 109, 209, 309, 409 permanent magnet, 9a, 109a, 209a, 309a Outer side surface, 9b, 109b, 209b Inner side surface, 21 slit, 23 orientation, 125a, 125b, 227a, 227b, 329c, 431d Chamfered portion.

Claims (10)

A rotor of an embedded permanent magnet electric motor comprising a core having a plurality of magnet insertion holes and a plurality of permanent magnets accommodated in each of the plurality of magnet insertion holes,
In the core, a slit is formed between each of the magnet insertion holes and the outer surface of the core,
Each of the permanent magnets extends in a direction perpendicular to the magnetic pole center line,
The magnetization orientations of the permanent magnets are parallel to each other in the permanent magnets and are inclined with respect to the magnetic pole center line.
Rotor of permanent magnet embedded motor. In the corner portion of the outer surface of the permanent magnet, a chamfered portion having the same inclination direction as the direction of magnetization orientation is formed.
The rotor of the permanent magnet embedded type electric motor according to claim 1. A chamfered portion in the same inclination direction as the direction of magnetization orientation is formed at the corner of the inner surface of the permanent magnet.
The rotor of the permanent magnet embedded type electric motor according to claim 1 or 2. Further comprising a chamfer provided symmetrically with respect to the chamfer and the magnetic pole center line,
The rotor of the permanent magnet embedded type electric motor according to claim 2 or 3. The chamfered portion is provided such that an end surface of the permanent magnet is configured by one surface.
The rotor of the permanent magnet embedded type electric motor according to claim 2 or 3. The chamfered portion is provided in rotational symmetry with respect to the symmetry center of the permanent magnet.
The rotor of the permanent magnet embedded type electric motor according to claim 2 or 3. The permanent magnet is a rare earth magnet.
The rotor of the permanent magnet embedded type electric motor according to any one of claims 1 to 6. The magnetization orientation angle, which is the inclination of the magnetization orientation with respect to the magnetic pole center line, is 0 ° <θ ≦ 8 °.
The rotor of the permanent magnet embedded type electric motor according to any one of claims 1 to 7. A compressor comprising an electric motor and a compression element,
The rotor of the electric motor is a rotor of an embedded permanent magnet electric motor according to any one of claims 1 to 8.
Compressor.   A refrigeration air conditioner comprising the compressor of claim 9 as a component of a refrigeration circuit.

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