JPH099537A - Permanent magnet type motor - Google Patents

Abstract

(57) Abstract: In a permanent magnet type motor, the rotor iron core is provided with necessary strength, and the leakage magnetic flux between adjacent magnetic pole portions is reduced to improve motor efficiency. A rotor core 4 is provided with a V-shaped magnet insertion hole 5, into which a permanent magnet 10 having a rectangular cross section is inserted.
The magnetic pole connecting portion 7 existing between the side surface of the permanent magnet 10 and the outer peripheral portion of the rotor core 4 is formed by the narrow width portion 7a and the wide width portion 7b adjacent thereto. In the narrow width portion 7a, the magnetic flux is saturated to reduce the leakage of the magnetic flux between the adjacent magnetic pole portions 6, and in the wide width portion 7b, the surface opposes the centrifugal force of the permanent magnet 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type motor used as a motor for driving a compressor such as a refrigerator or an air conditioner.

[0002]

2. Description of the Related Art In recent years, with the development of permanent magnet materials and control devices, permanent magnet type motors have come into general use as compressor motors for refrigerators, air conditioners and the like. In the permanent magnet type motor, it is required that the size of the permanent magnet embedded in the rotor be as large as possible to secure the required magnetic flux amount. Therefore, various proposals have been made regarding the arrangement of the permanent magnet. One of them is the permanent magnet V
There is one arranged in a V shape (hereinafter referred to as a V-shaped rotor).

FIG. 12 is a partial cross-sectional view showing a V-shaped rotor of a conventional permanent magnet type motor disclosed in, for example, Japanese Utility Model Laid-Open No. 6-66277. In the figure, reference numeral 1 denotes a cylindrical stator core, in which slots 2 are punched out by the number determined by the number of poles, the number of phases, etc., and the coil 3 is wound between the slots 2. There is. Reference numeral 4 denotes a cylindrical rotor core arranged inside the stator core 1, and has a V-shaped magnet insertion hole 5 penetrating in the axial direction, and the V-shaped opening width of the magnet insertion hole 5. W ₁ is slightly narrower than the pole pitch width W ₂ .

Reference numeral 6 denotes a magnetic pole portion located on the outer peripheral portion of the rotor core 4 and narrowed to the V-shaped inner edge of the magnet insertion hole 5, and 7 denotes a magnetic pole connecting portion for connecting adjacent magnetic pole portions 6 at the outer peripheral portion. Reference numeral 8 is a yoke portion surrounded by the V-shaped outer edge of the magnet insertion hole 5, 9 is an inner / outer peripheral connection portion that is sandwiched between the adjacent magnet insertion holes 5 and that connects the magnetic pole portion 6 and the yoke portion 8. 7 has a width necessary for strength, and the inner and outer peripheral connecting portions 9 are set to a width that does not affect the leakage magnetic flux.

Reference numeral 10 denotes a permanent magnet inserted into the magnet insertion hole 5, which has a shape similar to the magnet insertion hole 5 and is symmetrical at the bottom of the V-shape.
It is divided and embedded to form a magnetic pole for one pole. Then, the polarities of the permanent magnets 10 of the adjacent magnetic poles are arranged to be opposite to each other. Reference numeral 11 denotes a rotor shaft insertion hole.

FIG. 13 is a transverse sectional view showing a V-shaped rotor of a conventional permanent magnet type motor disclosed in, for example, Japanese Patent Application Laid-Open No. 2-179253. In this example, a permanent magnet 10 having a rectangular cross section is inserted into the magnet insertion hole 5 arranged in a V shape, and in order to prevent the leakage of magnetic flux between the adjacent magnetic pole portions 6, the magnetic pole connecting portion 7 is provided. It is configured to cut a part. That is, the S pole 6a of the magnetic pole 6 is integrated with the yoke 8, but the N pole 6b is separated from the yoke 8. A space between the magnet insertion hole 5 and the permanent magnet 10 is filled with a curable non-magnetic substance 12.

The conventional V-shaped rotor is constructed as described above. For example, assuming that the coil 3 is a three-phase winding, and when a three-phase alternating current is passed through this coil 3, the current flowing through the coil 3 and the magnetic flux of the permanent magnet 10 are increased. Generated by the torque (permanent magnet field torque) and the magnetic flux generated by the current flowing through the coil 3,
A torque (reluctance torque) that attempts to move to a magnetically stable position is generated, and the rotor core 4 rotates.
That is, the magnetic flux generated by the permanent magnet 10 is related to the torque generated by the motor.

[0008]

The V-shaped rotor of the conventional permanent magnet type motor as described above has the following problems. (1) In the structure shown in FIG. 12, since the permanent magnet 10 divided into two at the bottom of the V-shape is embedded, the centrifugal force acting on the permanent magnet 10 is applied to the outer peripheral portion of the rotor core 4 of the magnet insertion hole 5. Concentrate on one corner. Therefore, the width of the magnetic pole connecting portion 7 in the radial direction must be considerably large in terms of strength.

Therefore, the leakage magnetic flux generated in the magnetic pole connecting portion 7 increases, the magnetic flux interlinking with the coil 3 decreases, and the efficiency of the motor decreases. Further, since the permanent magnet 10 having a cross section similar to the magnet insertion hole 5 is used, the permanent magnet 10
Processing becomes difficult, and the cost of the permanent magnet 10 increases.

(2) In the structure of FIG. 13, a part of the magnetic pole connecting portion 7 is cut in order to prevent the leakage of the magnetic flux between the adjacent magnetic pole portions 6, so that the magnetic pole portion 6 (the N pole in the figure) is cut. 6b)
Is separated from the yoke portion 8. Therefore, the curable non-magnetic substance 12 must be filled in the gap between the magnet insertion hole 5 and the permanent magnet 10 so that the magnetic pole portion 6 is not separated from the rotor core 4 by the centrifugal force when the rotor core 4 rotates. Therefore, the processing man-hours increase and the cost increases.

The present invention has been made in order to solve the above problems, and it is possible to reduce the leakage magnetic flux between adjacent magnetic pole portions while maintaining the strength required for the rotor core, and to manufacture at low cost. An object of the present invention is to provide a permanent magnet type motor configured as described above.

[0012]

A permanent magnet type motor according to a first aspect of the present invention has permanent magnets arranged in a V shape formed in a rectangular cross section, and the side surfaces of the permanent magnets and the rotor core are The magnetic pole connecting portion existing between the outer peripheral portion and the outer peripheral portion is formed by a narrow portion and a wide portion connected to the narrow portion.

In the permanent magnet type motor according to the second aspect of the present invention, in the first aspect of the invention, the side corresponding to the inside of the V-shape inside the side of the magnet insertion hole and the side on the outer peripheral side of the rotor core are provided. Letting P be the number of poles and S be the number of storage slots of the coil wound around the stator core, the angle θ between two lines connecting the two corners intersecting with each other and the center of the rotor core is (240 ° / P)-(360 ° / S) ≦ θ ≦ (240 ° / P)
It is set within the range of + (360 ° / S).

In the permanent magnet type motor according to the third aspect of the present invention, steel plates are laminated, end plates are arranged on both end faces, and the permanent magnets arranged in a V shape are traversed by a stator core fastened with rivets. The surface is formed in a rectangular shape, and the magnetic pole connecting portion existing between the side surface of the permanent magnet and the outer peripheral portion of the rotor core is formed by the narrow width portion and the wide width portion connected to the narrow width portion.

The permanent magnet motor according to a fourth aspect of the present invention is the permanent magnet motor according to the third aspect of the present invention, in which the side corresponding to the inside of the V-shape inside the side of the magnet insertion hole and the side on the outer peripheral side of the rotor core. Letting P be the number of poles and S be the number of storage slots of the coil wound around the stator core, the angle θ between two lines connecting the two corners intersecting with each other and the center of the rotor core is (240 ° / P)-(360 ° / S) ≦ θ ≦ (240 ° / P)
It is set within the range of + (360 ° / S).

A permanent magnet motor according to a fifth aspect of the present invention is the permanent magnet motor according to the third or fourth aspect of the invention, wherein the rivet position is located on the inner peripheral side of the rotor core and between the adjacent permanent magnets. is there.

A permanent magnet motor according to a sixth aspect of the present invention is the permanent magnet motor according to any one of the first to fifth aspects, wherein a permanent magnet is inserted into the magnet insertion hole through a gap.

Further, a permanent magnet type motor according to a seventh aspect of the present invention is the permanent magnet type motor according to the sixth aspect of the present invention, in which a protruding portion is formed inside a magnet insertion hole of a single steel plate arranged on the end face of the rotor core. .

The permanent magnet type motor according to the eighth aspect of the present invention is the permanent magnet motor according to any one of the first to seventh aspects of the invention, wherein one sheet arranged on the end face of the rotor core forms the magnet insertion hole. The lower end portion of the V-shaped hole is separated and the outer peripheral side and the inner peripheral side of the steel plate are connected to each other.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. FIG. 1 is a cross-sectional view of a rotor core portion showing an embodiment of the first invention of the present invention, and portions similar to those of a conventional device are designated by the same reference numerals (the same applies to the following embodiments).

In the figure, reference numeral 5 is a magnet insertion hole arranged in a V shape, and in this embodiment, the angle of the V shape is set to 90 °, and a permanent magnet having a rectangular cross section is formed therein. 10 is inserted. Therefore, the permanent magnets 10 for one pole are arranged 90 ° apart from each other, and the permanent magnets 10 adjacent to each other are arranged in parallel with each other. Further, the magnetic pole connecting portion 7 existing between the side surface of the permanent magnet 10 and the outer peripheral portion of the rotor core 4 is composed of a narrow width portion 7a having a narrow radial width and a wide width portion 7b having a wide radial width. Has been formed.

In the permanent magnet type motor constructed as described above, since the magnetic pole connecting portion 7 is provided with the narrow width portion 7a, the magnetic resistance between the adjacent magnetic pole portions 6 increases. The radial width of the narrow portion 7a is set so that the leakage magnetic flux between the magnetic pole portions 6 is saturated. Therefore, the magnetic pole portion 6
Leakage of magnetic flux between them is reduced, and it is possible to prevent a decrease in motor efficiency.

Further, since the magnetic pole connecting portion 7 is also provided with the wide width portion 7b, it is possible to receive the centrifugal force of the permanent magnet 10 at a portion having a large radial width and at the surface. That is,
In the case of FIG. 5, the centrifugal force of the permanent magnet 10 is received by one point, but this is received by the surface. Therefore, the strength of the rotor core 4 against the centrifugal force has a sufficient margin.

In the first embodiment, the permanent magnet 10 has a rectangular cross section. Since the permanent magnet 10 having a rectangular cross section is easy to process, the cost is low, and an inexpensive permanent magnet motor can be configured.

Embodiment 2 2 to 4 are views showing an embodiment of the second invention of the present invention, FIG. 2 is a transverse cross-sectional view of a main part of a permanent magnet type motor, and FIG. 3 is an inverter circuit diagram for driving a permanent magnet type motor. 4 is a magnetic flux distribution chart. In FIG. 2, 5a is a side corresponding to the inside of the V-shape of the side of the magnet insertion hole 5, 5b is a side on the outer peripheral side of the rotor core 4, and 5c is a corner where both sides 5a and 5b intersect. is there.

[0026] In FIG. 1, the width W ₁ of the magnet insertion holes 5 showed that slightly narrower than the pole pitch width W _2, Embodiment 2
Then, as shown in FIG. 2, the angle θ formed by the two lines connecting the corner 5c and the center of the rotor core 4 is (240 ° / P) − (360 ° / S) ≦ θ ≦ (240 ° / P)
It was assumed to be within the range of + (360 ° / S). Here, P is the number of poles, and S is the number of slots 2. That is, the angle θ is set to the effective center angle (240 ° / P) on which the driving torque acts, and
It is set within an angle range in which the central angle (360 ° / S) for the pitch is adjusted.

In FIG. 3, reference numeral 21 is a DC power source, and 22U to 22U.
22W is an inverter circuit which is connected to the DC power source 21 and is composed of a transistor and a diode for free-flowing which is connected in parallel to the transistor. FIG. 3 shows a widely used three-phase voltage source inverter circuit. Two for each phase and six for three phases. Reference numeral 23 is a permanent magnet type motor connected to the AC side of the inverter circuits 22U to 22W, and 24 is a control circuit for controlling on / off of the transistors of the inverter circuits 22U to 22W.

The conduction method for each transistor is 120 degrees,
There are 150 degrees and 180 degrees. In order to adopt the sensorless position detection method, a section in which the outputs of the inverter circuits 22U to 22W are zero is necessary to separate the induced voltage waveform and the inverter output waveform. Therefore, the 180-degree conduction method cannot be used. Therefore, for example, if the 120-degree conduction method is adopted, in the conventional permanent magnet type motor 23, the drive torque of approximately 120 degrees in electrical angle acts on the magnetic flux generated by the permanent magnet 10 as one pole. become.

Therefore, the electrical angle shown by the shaded area in FIG. 4A is 0 to 30 degrees and 150 to 1 degrees.
The magnetic flux generated in the portion corresponding to 80 degrees hardly acts as the drive torque of the motor. However, in the structure shown in FIG. 2, the magnetic flux distribution of the permanent magnet 10 is magnetically protruding so as to correspond to the energized section, and the magnetic flux in this portion is strengthened. Therefore, as shown in FIG. 4B, the magnetic flux density for one pole increases the magnetic flux at a position corresponding to an electrical angle of 30 degrees to 150 degrees, so that the torque for one phase also increases. Therefore, the combined torque of the three phases is also increased, and the efficiency of the motor is improved.

Embodiment 3 FIG. 5 is a view showing a rotor core portion showing an embodiment of a third invention of the present invention.
5A is an exploded perspective view, and FIG. 5B is a cross-sectional view. In the figure, a rotor core 4 is formed into a cylindrical shape by laminating a large number of punched steel plates 4a, and has a V-shaped magnet insertion hole 5.
It has a permanent magnet 10 inserted in the magnet insertion hole 5.
Further, the punched steel plate 4a is provided with a rivet hole 32, and a pair of end plates 31, 31 arranged on both end surfaces of the rotor core 4 are provided.
And rivets 33 that connect the end plates 31, 31 together. Further, the magnetic pole connecting portion 7 existing between the side surface of the permanent magnet 10 and the outer peripheral portion of the rotor iron core 4 has a narrow width portion 7a having a narrow radial width and a wide width portion 7b having a wide radial width.
And formed.

In the permanent magnet type motor constructed as described above, since the magnetic pole connecting portion 7 is provided with the narrow width portion 7a, the magnetic resistance between the adjacent magnetic pole portions 6 increases. The radial width of the narrow portion 7a is set so that the leakage magnetic flux between the magnetic pole portions 6 is saturated. Therefore, the magnetic pole portion 6
Leakage of magnetic flux between them is reduced, and it is possible to prevent a decrease in motor efficiency.

Further, since the magnetic pole connecting portion 7 is also provided with the wide width portion 7b, it is possible to receive the centrifugal force of the permanent magnet 10 at a portion having a large radial width and at the surface. That is, in the case of FIG. 12, the centrifugal force of the permanent magnet 10 is received by one point, but this is received by the surface. Therefore, the strength of the rotor core 4 against the centrifugal force has a sufficient margin.

In the third embodiment, the permanent magnet 10 has a rectangular cross section. Since the permanent magnet 10 having a rectangular cross section is easy to process, the cost is low, and an inexpensive permanent magnet motor can be configured.

Embodiment 4 FIG. 6 is a cross-sectional view of a main portion of a rotor core showing an embodiment of the fourth aspect of the invention. 3 and 4 are also used in the fourth embodiment.
In the figure, 5a is a side corresponding to the inside of the V-shaped inside of the magnet insertion hole 5, 5b is a side on the outer peripheral side of the rotor core 4, and 5c is a corner where both sides 5a and 5b intersect. .

In FIG. 5B, the width W ₁ of the magnet insertion hole 5 is shown to be slightly narrower than the pole pitch width W _2. However, in the fourth embodiment, as shown in FIG. The angle θ between the two lines connecting the center of the rotor core 4 with the rotor core 4 is (240 ° / P)-(360 ° / S) ≦ θ ≦ (240 ° / P)
It should be within the range of + (360 ° / S). Here, P is the number of poles, and S is the number of slots 2. That is, the angle θ is set within an angle range in which the effective central angle (240 ° / P) on which the driving torque acts and the central angle (360 ° / S) for one pitch of the slots 2 are adjusted. The operation of this embodiment is the same as that of the first embodiment, and as described above, the driving torque is increased and the efficiency of the motor is improved.

Embodiment 5 FIG. 7 is a cross section of a stator core showing an embodiment of the fifth aspect of the invention. In FIG. 5B, the position of the rivet hole 32 is shown at the magnetic pole portion 6 of the rotor core 4, but in the fifth embodiment, as shown in FIG. 7, the position of the rivet hole 32 is at the rotor. Iron core 4
It is supposed to be arranged on the yoke portion 8. In the permanent magnet type motor shown in FIG. 5B, the centrifugal force of the end plate 31 which also serves as a balance weight acts on the magnetic pole portion 6 via the rivet 33.

Therefore, the centrifugal force of the end plate 31 is further applied to the narrow width portion 7a of the magnetic pole connecting portion 7 and the inner and outer peripheral connecting portions 9 where the strength of the rotor core 4 is weak.
However, in the permanent magnet type motor configured as shown in FIG. 7, the centrifugal force of the end plate 31 also serving as the balance weight is received by the strong portion of the rotor core 4 via the rivet 33. Therefore, the strength of the rotor core 4 against the centrifugal force has a sufficient margin.

Embodiment 6 FIG. FIG. 8 is a transverse cross-sectional view of a main part of a rotor core showing an embodiment of the sixth invention of the present invention. In this embodiment, the permanent magnet 10 is inserted into the magnet insertion hole 5 of the rotor core 4 through a gap. In the permanent magnet type motor configured as described above, since stress does not act on the rotor core 4 even when the permanent magnet 10 is inserted into the magnet insertion hole 5, the strength of the rotor core 4 against centrifugal force is improved. .

Embodiment 7. FIG. 9 is a diagram showing an embodiment of a seventh invention of the present invention, FIG. 9 (A) is a plan view of a punched steel plate arranged at one end of a rotor core, and FIG. 9 (B) is FIG. It is a principal part enlarged view of (A). In this embodiment, the punched steel plate 4b has a shape having a protrusion 5d inside the magnet insertion hole 5. It should be noted that this punched steel plate 4b is only one in the rotor iron core 4, and the rest is shown in FIG.
The punched steel plates 4a having the shape shown in are laminated.

In the permanent magnet motor constructed as described above, when the rotor core 4 is manufactured, the rotor core 4 is
By arranging the punched steel plate 4b shown in FIG. 9 so as to come to the lower side, the permanent magnet 10 is prevented from coming into contact with the protruding portion 5d and falling off from the rotor core 4, and the productivity is improved.

Further, the reason why there is only one punched steel plate 4b having the protruding portion 5d is that one punched steel plate 4b is sufficient as long as the weight of the permanent magnet 10 is supported.
If the punched steel plate 4b having the protruding portion 5d is used in a large amount, the axial length of the permanent magnet 10 becomes shorter than the axial length of the rotor core 4, and the performance is deteriorated if the rotor has the same core width. The reason is that

Embodiment 8 FIG. FIG. 10 shows the eighth embodiment of the present invention.
10 is a view showing an embodiment of the invention, FIG. 10 (A) is a plan view of a punched steel plate arranged at one end of a rotor core, FIG.
FIG. 10B is an enlarged view of a main part of FIG. In this embodiment, the punched steel plate 4b has a shape having inner and outer peripheral connecting portions 9 that connect the magnetic pole portion 6 and the yoke portion 8 even inside the magnet insertion hole 5. It should be noted that this punched steel plate 4b is only one of the rotor core 4 and the rest is as shown in FIG.
The punched steel plates 4a having the shape shown in are laminated.

Since the permanent magnet motor constructed as described above has the inner and outer peripheral connecting portions 9 for connecting the magnetic pole portion 6 and the yoke portion 8, the core is twisted during punching and stacking. Does not occur. Therefore, no stress is generated and the strength of the rotor core 4 against the centrifugal force is improved. Further, the verticality of the rotor core 4 is improved, and the rotor assembly accuracy is improved.

A punched steel plate 4 having inner and outer peripheral connecting portions 9
The reason why there is only one b is that if many punched steel plates 4b having the inner and outer peripheral connecting portions 9 are used, the axial length of the permanent magnet 10 becomes shorter than the axial length of the rotor core 4. , And the magnetic flux of the permanent magnet 10 leaks from the magnetic pole portion 6 to the yoke portion 8, so that the performance deteriorates if the rotor has the same core width.

Ninth Embodiment FIG. 11 shows a seventh embodiment of the present invention.
It is a figure which shows one Embodiment which combined invention and 8th invention, FIG.11 (A) is an enlarged view of a principal part. In this embodiment, the punched steel plate 4b has a protrusion 5e inside the magnet insertion hole 5.
And an inner-outer peripheral connecting portion 9 connecting the magnetic pole portion 6 and the yoke portion 8
And has a shape with. In addition, this punched steel plate 4b
Is only one of the rotor cores 4, and the rest are shown in FIG.
A punched steel plate 4a having a shape shown in (A) is laminated.

In the permanent magnet type motor constructed as described above, when the rotor core 4 is manufactured, the rotor core 4 is arranged so that the punched steel plate 4b shown in FIG. The permanent magnet 10 does not come into contact with the protruding portion 5e and fall off from the rotor core 4, and the productivity is improved. Further, since the inner and outer peripheral connecting portions 9 that connect the magnetic pole portion 6 and the yoke portion 8 are provided, no twist occurs in the iron core during punching and stacking of the iron core, so stress does not occur and the rotor iron core 4 The strength against centrifugal force is improved. Further, the verticality of the rotor core 4 is improved, and the rotor assembly accuracy is improved.

The reason why there is only one punched steel plate 4b having the protruding portion 5e and the inner and outer peripheral connecting portions 9 is that the permanent magnet 1
One punching steel plate 4b is enough to support the weight of 0, and if many punching steel plates 4b are used, the axial length of the permanent magnet 10 relative to the axial length of the rotor core 4 is increased. Becomes shorter, and the permanent magnet 10
This is because the magnetic flux of (4) leaks from the magnetic pole portion 6 to the yoke portion 8, and the performance of the rotor having the same core width deteriorates.

[0048]

As described above, according to the first aspect of the present invention, the magnetic pole connecting portion between the side surface of the permanent magnet having a rectangular cross section and the outer peripheral portion of the rotor core is connected to the narrow portion and the wide portion. Since the magnetic flux is saturated in the narrow width portion and the leakage of the magnetic flux between the adjacent magnetic pole portions is reduced, it is possible to prevent a decrease in motor efficiency. Further, in the wide portion, there is an effect that the surface can resist the centrifugal force of the permanent magnet, and the necessary strength against the centrifugal force of the rotor core can be obtained.

In the second invention, the angle θ formed by the line connecting the corner of the V-shaped opening of the permanent magnet and the center of the rotor core is (240 ° / P) − (360 ° / S) ≦ θ ≦ (240 ° / P)
Since it is set within the range of + (360 ° / S), the width of the magnetic pole part becomes the width corresponding to the energization section of the stator coil, and magnetic protrusions are formed in this part, which affects the driving torque of the motor. The generated magnetic flux increases, the generated drive torque increases, and the efficiency of the motor can be improved.

According to the third aspect of the invention, the magnetic pole connecting portion between the side surface of the permanent magnet having a rectangular cross section and the outer peripheral portion of the rotor core made of laminated steel plates is composed of the narrow width portion and the wide width portion connected thereto. Since it is formed, the magnetic flux is saturated in the narrow width portion, the leakage of the magnetic flux between the adjacent magnetic pole portions is reduced, and it is possible to prevent a decrease in motor efficiency. Further, in the wide portion, there is an effect that the surface can resist the centrifugal force of the permanent magnet, and the necessary strength against the centrifugal force of the rotor core can be obtained.

In the fourth invention, the angle θ formed by the line connecting the corner of the V-shaped opening of the permanent magnet and the center of the rotor core is (240 ° / P) − (360 ° / S) ≦ θ ≦ (240 ° / P)
Since it is set within the range of + (360 ° / S), the width of the magnetic pole part becomes the width corresponding to the energization section of the stator coil, and magnetic protrusions are formed in this part, which affects the drive torque of the motor. The generated magnetic flux increases, the generated drive torque increases, and the efficiency of the motor can be improved.

Further, in the fifth aspect of the invention, since the rivet position is arranged on the inner peripheral side of the rotor core and between the adjacent permanent magnets, the centrifugal force of the end plate also serving as the balance weight is applied to the rotor core. The strength of the rotor core can be increased and the strength of the rotor core against centrifugal force can be improved.

Further, in the sixth aspect of the invention, since the permanent magnet is inserted into the magnet insertion hole through the gap, no stress is generated in the rotor core when the permanent magnet is inserted into the rotor core, and the rotor core is prevented. This has the effect of improving the strength of the iron core against centrifugal force.

Further, in the seventh invention, since the protruding portion is formed inside the magnet insertion hole of the one steel plate arranged on the end surface of the rotor iron core, this steel plate is arranged so as to come to the lower side when the rotor is manufactured. By doing so, even if there is a clearance fit between the permanent magnet and the rotor core, the permanent magnet will not fall off from the rotor core, and the productivity can be improved.

Further, in the eighth aspect of the invention, one sheet arranged on the end face of the rotor core is divided into the outer peripheral side and the inner peripheral side of the steel plate by separating the lower end of the V-shaped hole forming the magnet insertion hole. Since they are connected to each other, twisting does not occur in the rotor core during punching of the steel plate and lamination of the rotor core, and it is possible to improve the strength of the rotor core against centrifugal force and the rotor assembly accuracy. is there.

[Brief description of drawings]

FIG. 1 is a transverse sectional view of a rotor core portion showing a first embodiment of the present invention.

FIG. 2 is a lateral cross-sectional view of a main part of a permanent magnet type motor showing a second embodiment of the present invention.

FIG. 3 is a circuit diagram of a permanent magnet type motor driving inverter circuit according to a second embodiment of the present invention.

4A and 4B are magnetic flux distribution diagrams showing a second embodiment of the present invention, where FIG. 4A is a conventional permanent magnet motor, and FIG. 4B is a permanent magnet motor according to FIG.

5A and 5B are views of a rotor core showing a third embodiment of the present invention, in which FIG. 5A is an exploded perspective view and FIG.

FIG. 6 is a lateral cross-sectional view of a main part of a rotor core showing a fourth embodiment of the present invention.

FIG. 7 is a cross sectional view of a rotor core showing a fifth embodiment of the present invention.

FIG. 8 is a cross-sectional view of a main part of a rotor core showing a sixth embodiment of the present invention.

9A and 9B are views of a rotor core according to a seventh embodiment of the present invention, in which FIG. 9A is a plan view of a punched steel plate, and FIG. 9B is an enlarged view of a main part of FIG.

FIG. 10 is a diagram of a rotor core showing an eighth embodiment of the present invention, (A) is a plan view of a punched steel plate, and (B) is an enlarged view of a main part of (A).

11A and 11B are views of a rotor core according to a ninth embodiment of the present invention, in which FIG. 11A is a plan view of a punched steel plate, and FIG. 11B is an enlarged view of a main part of FIG.

FIG. 12 is a transverse cross-sectional view of a main part of a conventional permanent magnet type motor.

FIG. 13 is a transverse sectional view of a rotor core portion of a conventional permanent magnet type motor.

[Explanation of symbols]

1 stator core, 2 slots, 3 coils, 4 rotor core, 4a punched steel plate, 5 magnet insertion holes, 5a, 5b
Side of magnet insertion port, 5c corner, 5d, 5e protrusion, 6
Magnetic pole portion, 7 magnetic pole connecting portion, 7a narrow width portion, 7b wide width portion, 9 inner and outer peripheral connecting portion, 10 permanent magnet, 31 end plate,
32 rivet holes, 33 rivets.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Taiichi Kobayakawa 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Yukihiro Yamashiro 2-3-2, Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Kazuhiko Baba 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (8)

[Claims] 1. A cylindrical rotor core is arranged inside a cylindrical stator core around which a coil is wound, and this V-shape is formed in the rotor core in the axial direction thereof. Has a magnet insertion hole disposed on the outer peripheral side of the rotor core, and a permanent magnet is inserted into the magnet insertion hole such that the insides of the V-shapes have the same poles.
The permanent magnet is formed in a rectangular cross section, and the magnetic pole connecting portion existing between the side surface of the permanent magnet and the outer peripheral portion of the rotor core is formed of a narrow width portion and a wide width portion connected to the narrow width portion. A permanent magnet type motor characterized by. 2. The two corners where the side corresponding to the inside of the V-shape of the sides of the magnet insertion hole and the side on the outer peripheral side of the rotor core intersect with the center of the rotor core. Letting the number of poles be P and the number of coil storage slots in the stator core be S, the angle θ sandwiched by the lines is (240 ° / P)-(360 ° / S) ≤ θ ≤ (240 ° / P)
The permanent magnet motor according to claim 1, wherein the permanent magnet motor is set within a range of + (360 ° / S). 3. A cylindrical rotor core, in which a number of steel plates are laminated, is arranged inside a cylindrical stator core around which a coil is wound, and the rotor core has a V-shaped axial direction. Has a magnet insertion hole disposed on the outer peripheral side of the rotor core, and the permanent magnet is formed in the magnet insertion hole so that the insides of the V shape have the same poles. In the motor that is inserted, the end plates are arranged on both end faces of the rotor core and both end faces of the permanent magnet, respectively, and the rotor core and the end plates are axially penetrated and fastened by rivets. The magnet is formed in a rectangular cross section, and the magnetic pole coupling portion existing between the side surface of the permanent magnet and the outer peripheral portion of the rotor iron core is formed of a narrow width portion and a wide width portion connected to the narrow width portion. Permanent magnet type motor. 4. The two corners where the side corresponding to the inside of the V-shape inside the side of the magnet insertion hole and the side on the outer peripheral side of the rotor core intersect and the center of the rotor core are connected. Assuming that the angle θ between the lines is P, where P is the number of poles, and S is the number of coil storage slots in the stator core, (240 ° / P) − (360 ° / S) ≦ θ ≦ (240 ° /
The permanent magnet type motor according to claim 3, wherein it is set within a range of (P) + (360 ° / S). 5. The permanent magnet type motor according to claim 3, wherein the position of the rivet is arranged on the inner peripheral side of the rotor core and between the adjacent permanent magnets. 6. The permanent magnet type motor according to claim 1, wherein a permanent magnet is inserted into the magnet insertion hole through a gap. 7. A steel sheet forming a rotor core, wherein a protrusion is formed inside one magnet insertion hole arranged on an axial end face of the rotor core. Permanent magnet type motor. 8. One of the steel plates constituting the rotor core, which is disposed on the axial end face of the rotor core, has the V-shaped hole forming the magnet insertion hole separated from the lower end portion thereof. The permanent magnet type motor according to any one of claims 1 to 7, wherein the outer peripheral portion and the inner peripheral portion of the steel plate are connected to each other.