JP2004357430A - Permanent magnet motor and compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high-efficiency compressor reduced in vibration and noise by suppressing the lowering of the efficiency of a permanent magnet type motor, suppressing the occurrence of vibration and noise, and by using this motor. <P>SOLUTION: In the compressor, the axial length of a rotor core is made to be the same of that of a stator core, a high-density member having a diameter smaller than the outside diameter of the rotor core is installed at the end of the rotor core, and the axial length of a rotor including the high-density member is made to be longer with respect to the axial length of a stator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor used for a compressor such as a refrigerator, a dehumidifier, and an air conditioner, and a compressor using the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, in a motor for driving a compressor for an air conditioner or a refrigerator, for example, a permanent magnet type motor having easy motor speed control and high motor efficiency has been used.
Permanent magnet type motors have been used, for example, as follows to prevent vibration and operation noise during compressor operation.
In order to correct the imbalance at the output shaft end of the shaft, balance weights are provided on both sides of the rotor, the axial length of the rotor core is made larger than the axial length of the stator core, and the axial center of the rotor core is From the center in the axial direction. (For example, refer to Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2000-134882 (page 5, page 6, FIG. 3)
[0004]
[Problems to be solved by the invention]
As described above, in the conventional permanent magnet type motor for driving the compressor, the axial length of the rotor core is configured to be larger than the axial length of the stator core. When a magnet-embedded rotor configured to be embedded inside the rotor is used, the magnetic flux generated by the permanent magnet passes through the thin connecting portion of the outer peripheral portion between the magnet poles at the axial end of the rotor core, and the magnetic flux of the adjacent magnetic pole is formed. Short-circuit magnetic flux (Φ1) is generated in the path returning to the permanent magnet, the effective magnetic flux contributing to the torque is reduced, the current for obtaining the desired torque is increased, and the copper loss is increased (Problem A).
[0005]
In addition, a magnetic flux generated by the current flowing through the stator winding generates a leakage magnetic path in a path passing through the outer peripheral end in the axial direction of the rotor core, so that more current is required to obtain a desired torque. And the copper loss was increased (Problem B).
[0006]
Further, since the coil end portion of the stator winding and the rotor core are arranged to face each other, the magnetic flux (Φ2) generated by the current flowing through the stator winding changes perpendicularly to the end of the rotor core. In addition, an eddy current loss occurs at the end of the rotor core portion facing the coil end portion of the stator winding, thereby increasing the iron loss (Problem C).
[0007]
In addition, even if the material of the end of the rotor core facing the coil end of the stator winding is made of a non-magnetic metal material, an eddy current is generated in the non-magnetic metal material. And increased iron loss.
[0008]
Also, if the material of the end of the rotor core facing the coil end of the stator winding is made of a non-magnetic resin, the height of the balance weight becomes large to obtain a sufficient moment, and the compressor is It was getting bigger.
[0009]
As described above, even if the conventional permanent magnet type motor can suppress the vibration and noise, it was made to solve the problem that the efficiency was reduced due to the occurrence of copper loss and iron loss at the same time. An object of the present invention is to suppress a decrease in efficiency of a permanent magnet type motor and to suppress vibration and noise. It is another object of the present invention to obtain a compressor with high efficiency and low vibration and noise by using this permanent magnet type motor.
[0010]
[Means for Solving the Problems]
The present invention provides a permanent magnet type motor in which a high-density member made of a high-density member is provided at an axial end of a rotor core, and the outer diameter of the high-density member is smaller than the outer diameter of the rotor core. And a compressor using this permanent magnet type motor.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view of a compressor incorporating a permanent magnet type motor for driving a compressor according to Embodiment 1 of the present invention, and FIG. 2 is a transverse sectional view of a rotor of the permanent magnet type motor. FIG. 3 is a view showing a compression mechanism of the compressor.
In these figures, in the compressor, a permanent magnet type motor including a stator 5 and a rotor 6 is arranged at an upper part in a closed container 7, a compression mechanism part 15 is arranged at a lower part, and both are connected by a drive shaft 13, The drive shaft 13 is rotated by the permanent magnet type motor, and the compression mechanism 15 is operated to compress the drawn refrigerant.
[0012]
The stator 5 of the permanent magnet type motor has a stator core portion 5a which is a hollow laminated body formed by laminating a plurality of disk-shaped electromagnetic steel plates having a thickness of about 0.3 to 0.5 mm and having a central portion opened in the axial direction. The stator core 5a is arranged so as to surround the rotor 6 disposed at the center with the gap 12 therebetween, and the outer peripheral side is sealed by means of shrink fitting or welding. Attached directly to the container 7 and held. A plurality of slots (not shown) are provided in the stator core portion 5 of the stator 5, and a coil is wound in the slots, and a winding 11 such as a distributed winding or a concentrated winding is provided.
[0013]
The rotor 6 has a rotor core 6a fixed to a drive shaft 13 penetrating the center in the axial direction and upper and lower ends of the rotor core 6a. Similarly, the rotor 6 is fixed to the drive shaft 13 penetrating the center in the axial direction. Formed from a high-density member portion 6b made of a high-density member.
The rotor core portion 6a is formed by laminating a plurality of disk-shaped electromagnetic steel plates having a thickness of about 0.3 to 0.5 mm with an open central portion in the axial direction and integrating them. The rotor core 6a is provided with a plurality of magnet insertion holes 9 in the axial direction about the drive shaft 13 on a plane orthogonal to the drive shaft 13, and the permanent magnet 10 is inserted over the entire rotor core 6a in the axial direction. Is done. As the permanent magnet 10, a sintered rare earth magnet mainly containing neodymium, iron, boron or the like is used.
The stator core part 5a and the rotor core part 6a are formed concentrically in the direction of the drive shaft 13 with a predetermined gap 12 provided with the rotor core part 6a at the center.
[0014]
The high-density members 6b attached to the upper and lower ends of the rotor core 6a are hollow cylinders whose outer diameter is smaller than the outer diameter of the rotor core 6a by a predetermined amount. The high-density member 6b is made of a non-magnetic metal. That is, brass (an alloy of copper and zinc) which is a non-magnetic material of metal is used. In addition, copper, palladium, tungsten, nickel chloride, stainless steel, or the like may be used as long as it is a high-density nonmagnetic material.
The compression mechanism 15 side of the drive shaft 13, which penetrates and fixes the center of the rotor core 6 a and the high-density member 6 b, is rotatably held by bearings 14, 14 at the lower part of the closed casing 7.
[0015]
Next, as shown in FIG. 1, a dimensional relationship between the stator 5 and the rotor 6 will be described.
The axial length L1 of the rotor core 6a of the rotor 6 is substantially the same as the axial length L2 of the stator core 5a of the stator 5, and the outer diameter D1 of the rotor core 6a is provided at both ends of the rotor core 6a. Also, the high-density member 6b having an outer diameter D2 smaller by a predetermined amount is attached, and the axial length L3 of the rotor 6 including the high-density member 6b is made larger by a predetermined amount than the axial length L2 of the stator core 5a. It was configured to be.
For example, the outer diameter D2 of the high-density member 6b is configured to be about 0.95 times or less the outer diameter D1 of the rotor core 6a. That is, the outer diameter dimension D2 of the high-density member 6b is high enough to prevent leakage current Φ2 generated from the coil end portion 5b from interlinking with the high-density member 6b when the permanent magnet type motor is driven, so that eddy current does not flow. The outer diameter D2 of the density member 6b is configured to be small.
[0016]
If the axial length L3 of the rotor 6 including the high-density member 6b is made larger by a predetermined amount than the axial length L2 of the stator core 5a, the high-density member 6b becomes It may not be attached to both the upper end and the lower end of 6a, but may be attached to either one end.
Further, the axial length L1 of the rotor core 6a of the rotor 6 is not substantially equal to the axial length L2 of the stator core 5a of the stator 5, and the axial length L1 of the rotor core 6a is changed to the stator core. It may be longer than the axial length L2 of the portion 5a.
The length L1 in the axial direction of the rotor core 6a is made longer than the length L2 in the axial direction of the stator core 5a, and a permanent magnet 10 having substantially the same length as the axial length L1 of the rotor core 6a is provided. As a result, it is possible to increase the magnetic flux linking the stator core 5a through the outer periphery of the rotor core 6a, to reduce the current for obtaining the same torque, and to reduce the copper loss. As the axial length L1 of the rotor core 6a increases, the magnetic force does not necessarily increase as the axial length L1 increases. When the length is longer than a certain length, the magnetic flux does not increase any more. That is, it is desirable that the length L1 be 1.4 times or less the length L2.
[0017]
Further, when a rare earth magnet is used for the permanent magnet 10 of the rotor 6, the axial length L3 of the rotor 6 including the high-density member 6b is approximately two to three times the axial length L2 of the stator core 5a. It is configured to be. The axial length L3 of the rotor 6 is configured to be substantially equal to the rotor core width required to obtain the same efficiency when the rotor 6 is formed using a ferrite magnet. That is, it is designed such that the length in the axial direction is smaller by using a rare earth magnet than by using a ferrite magnet.
[0018]
Further, the outer periphery of the compression mechanism 15 is directly attached to the closed container 7 and fixed. As shown in FIG. 3, the compression mechanism 15 is rotatably fitted to a cylinder 18 having a cylinder chamber in which the suction port 16 and the discharge port 17 open, and an eccentric shaft of the drive shaft 13. And a vane 22 which is provided integrally with the piston 19 and is divided into a low-pressure chamber 20 of a compression chamber communicating with the suction port 16 and a high-pressure chamber 21 of the compression chamber communicating with the discharge port 17. Have been.
[0019]
When the drive shaft 13 of the permanent magnet type motor is rotationally driven by the inverter, the piston 19 rotates in conjunction therewith, and refrigerant gas is sucked into the cylinder chamber from the suction port 16, compressed and discharged from the discharge port 17. At this time, the drive shaft 13 of the permanent magnet type motor undergoes a large pressure fluctuation (driving torque fluctuation) during one rotation as shown in FIG.
[0020]
FIG. 5 shows a current waveform when this motor is driven by a 120-degree rectangular wave drive using an inverter. FIG. 5A shows a case where the high-density member 6b is not attached, and FIG. 5B shows a motor current waveform when the high-density member 6b is attached.
As shown in the comparison between the two figures, in a state where the high-density member 6b was not attached, a large current pulsation was generated during one rotation. Current pulsation during rotation can be reduced, and the current can be made uniform.
That is, the axial length L1 of the rotor core 6a is substantially the same as the axial length L2 of the stator core 5a, and the high-density member 6b made of a metal nonmagnetic material is provided at both ends of the rotor core 6a. With the provision, the inertial force of the rotor 6 can be increased, and the vibration and noise of the motor can be suppressed.
The length L1 of the rotor core 6a in the axial direction is made longer than the length L2 of the stator core 5a in the axial direction, and the permanent magnet 10 having substantially the same length as the length L1 of the rotor core 6a in the axial direction is used. The same effect can be obtained even if it is provided.
In addition, the high-density member 6b is not limited to the non-magnetic metal, but can be made of a high-density member to similarly increase the inertial force of the rotor 6.
The driving method is not limited to the 120-degree rectangular wave driving, and the same effect can be obtained by any other driving method such as a rectangular wave driving of 120 degrees or more and a sine wave driving.
[0021]
The rotor core 6a and the stator core 5a may have substantially the same axial length, or the rotor core 6a provided with the permanent magnets 10 having substantially the same length may have the same axial length as the stator core. Since the material of the high-density member 6b provided at the end of the rotor core 6a is made of a non-magnetic metal, the permanent member provided inside the rotor core 6a is longer than the axial length of the portion 5a. No leakage magnetic flux Φ1 is generated in a path where the magnetic flux generated by the magnet 10 flows through the adjacent magnet pole 10a through the high-density member 6b, that is, no short-circuit magnetic flux Φ1 is generated, and copper loss can be reduced (that is, a problem). A can be eliminated).
[0022]
The rotor core 6a and the stator core 5a may have substantially the same axial length, or the rotor core 6a provided with the permanent magnets 10 having substantially the same length may have the same axial length as the stator core. The length of the high-density member 6b is made longer than the axial length of the high-density member 6b, and the outer diameter of the high-density member 6b made of nonmagnetic metal and the outer diameter of the rotor core 6a are set to D2 <D1, that is, the outer diameter of the high-density member 6b. By making the dimension D2 smaller than the outer diameter dimension D1 of the rotor core 6a by a predetermined amount, the leakage magnetic flux Φ2 generated from the coil end 5b when the permanent magnet type motor is driven interlinks with the high-density member 6b to reduce eddy current. Since it does not flow, the eddy current loss of the rotor core 6a due to the stator winding 11 can be reduced, and a compressor motor that can reduce iron loss can be realized (that is, problem C can be solved).
In this case, the high-density member 6b may be made of a magnetic metal instead of a non-magnetic metal.
Further, even if the outer diameter dimension relationship between the high-density member 6b and the rotor core 6a is not set to D2 <D1, the high-density member 6b may be formed of a thin magnetic metal plate (for example, a thin brass plate) or a magnetic material. Even if a metal plate (for example, a thin electromagnetic steel plate) is laminated via an insulating film, the problem C can be solved.
[0023]
The rotor core 6a and the stator core 5a may have substantially the same axial length, or the rotor core 6a provided with the permanent magnets 10 having substantially the same length may have the same axial length as the stator core. Since the non-magnetic metal high-density member portion 6b having a diameter D2 smaller than the outer diameter D1 of the rotor core portion 6a by a predetermined amount is attached to both ends of the rotor core portion 6a so as to be longer than the axial length of the portion 5a. The magnetic flux generated by the current flowing through the winding 11 of the stator 5 does not cause or reduces the occurrence of a leakage magnetic path in a path passing through the axially outer peripheral end of the rotor core 6a, thereby reducing copper loss (that is, copper loss). And the problem B can be solved).
In this case, the high-density member 6b may be made of a magnetic metal instead of a non-magnetic metal.
[0024]
In addition, by forming the high-density member 6b as a laminate in the same manner as the rotor core 6a, that is, by forming a thin magnetic metal plate laminate, the same progressive die as the rotor core 6a is formed. , The manufacturing process can be simplified, and the manufacturing becomes easier.
[0025]
As described above, according to the permanent magnet type motor of the present embodiment, the high-density member 6b made of a high-density member is provided at the axial end of the rotor core 6a, and the outer diameter of the high-density member 6b. Since the size is smaller than the outer diameter of the rotor core 6a, the inertial force of the rotor 6 can be increased, the eddy current loss of the rotor core 6a can be reduced, the iron loss can be reduced, and the motor efficiency can be reduced. Improvement and vibration / noise can be suppressed.
[0026]
Further, since the high-density member 6b made of a non-magnetic metal is provided at the axial end of the rotor core 6a, the inertia of the rotor 6 can be increased, and the rotor 6a flows inside the rotor core 6a. Leakage flux Φ1 is not generated, copper loss can be reduced, motor efficiency can be improved, and vibration and noise can be suppressed.
[0027]
Further, since the high-density member 6b made of the high-density member or the high-density member 6b made of magnetic metal is formed by laminating thin magnetic metal plates, the manufacturing process of the rotor 6 can be simplified. , Making it easier.
[0028]
Further, since the high-density member 6b is formed by laminating thin metal plates with an insulating film interposed therebetween, the inertia of the rotor 6 can be increased, and the eddy current loss of the rotor core 6a can be increased. Can be reduced, iron loss can be reduced, motor efficiency can be improved, and vibration and noise can be suppressed.
[0029]
In addition, by using the permanent magnet type motor for a compressor, noise generated through the closed container 7, the discharge pipe 25, and the suction pipe 26 can be suppressed, and noise as a unit such as an air conditioner or a refrigerator can be reduced. It is possible. That is, a highly efficient compressor capable of suppressing vibration and noise can be obtained. Furthermore, by forming the high-density member portion 6b of the rotor 6 of the permanent magnet type motor with a laminated body, the manufacture of the permanent magnet type motor is facilitated, and the cost of the compressor can be reduced.
[0030]
Embodiment 2 FIG.
FIG. 6 is a longitudinal sectional view of a compressor incorporating a permanent magnet type motor for driving a compressor according to a second embodiment of the present invention. FIGS. 7 and 8 show rotors of the permanent magnet type motor, respectively. FIGS. 9 and 10 are a cross-sectional view of the iron core portion and a cross-sectional view of the high-density member portion, respectively. FIGS. FIG.
In the present embodiment, the material of the high-density member 6b provided at the end of the rotor core 6a of the rotor 6 is made of a metal magnetic material, and the outer dimension D3 of the high-density member 6b is set to the rotor core. The outer diameter D4 of the magnet insertion hole 9 provided in the hole 6a is smaller than or equal to D4. Further, the high-density member 6b provided at the end of the rotor core 6a is formed by laminating thin electromagnetic steel sheets of about 0.3 to 0.5 mm each having an insulating coating on at least one surface.
[0031]
The high-density member 6b does not have to be attached to both the upper end and the lower end of the rotor core 6a, but may be attached to either one end. Also, the rotor core 6a and the stator core 5a have respective axial lengths. And other configurations including the point that the axial length of the rotor core 6a provided with the permanent magnets 10 having substantially the same length or the same length is longer than the axial length of the stator core 5a. Are the same as those in the first embodiment, and therefore, differences will be mainly described below.
[0032]
In the example of the rotor core 6 a and the high-density member 6 b of the rotor 6 shown in FIGS. 7 and 8, a permanent magnet inserted in a hexagonal shape on the cross section of the rotor core 6 a orthogonal to the axial direction of the drive shaft 13. A rare earth magnet 10 which is a flat permanent magnet 10 is inserted into the hole 9. Further, on the cross section of the rotor core 6a perpendicular to the axial direction of the drive shaft 13 (the plane perpendicular to the axis of the rotor core 6a), the outer dimensions of the opposed permanent magnet insertion holes 9 are D4, and the axial direction of the drive shaft 13 is Assuming that the outer dimension of the high-density member 6b corresponding to the axial direction in the cross section of the high-density member 6b perpendicular to the axis (the axis orthogonal to the high-density member 6b) is D3, the relationship between D3 and D4 corresponding in the axial direction is D3. Is D3 ≦ D4. In other words, the outer dimension D3 of the high-density member portion 6b in the cross section orthogonal to the axis is set to be equal to or less than the outer dimension D4 of the permanent magnet insertion hole 9 corresponding to the axial direction of the cross section orthogonal to the axis.
[0033]
As another example, as shown in FIG. 9, in a case where twelve permanent magnets 10 are arranged in a V-shape in a cross section perpendicular to the axis of the rotor core 6 a, the cross section perpendicular to the axis of the high-density member portion 6 b is As shown in FIG. 10, similarly, the relationship between D3 and D4 is set to D3 ≦ D4, and the external dimension D3 of the cross section orthogonal to the axis of the high-density member portion 6b is set to the external dimension corresponding to the axial cross section of the permanent magnet insertion hole 9 orthogonal to the axis. D4 or less.
[0034]
As described above, according to the permanent magnet type motor of the present embodiment, the high-density member 6b made of magnetic metal is provided at the axial end of the rotor core 6, and the high-density member 6b and the rotor core are provided. Assuming that D3 ≦ D4 when the outer dimensions corresponding to the axial direction of the magnet insertion hole 9 of each of the magnets 6a in the cross section perpendicular to the axis are D3 and D4, the high-density member 6b is used as in the first embodiment. It is possible to realize a compressor motor with low vibration and noise, and from the relationship of D3 ≦ D4, it is possible to prevent a decrease in effective magnetic flux due to the formation of the magnetic path of the permanent magnet 10 and to reduce copper loss (elimination of the problem A).
[0035]
In addition, the high-density member 6b realizes low vibration and low noise, and the high-density member 6b is formed by laminating a thin magnetic metal plate via an insulating film. The compressor motor that can reduce the eddy current loss of the iron core portion 6a and reduce the iron loss can be realized (elimination of the problem C).
It should be noted that a magnetic metal plate is also effective for solving the problem C even with a non-magnetic metal plate.
[0036]
Further, the configuration of the high-density member portion 6b is configured to be slightly smaller than the outer diameter dimension D4 of the magnet insertion hole 9 and larger than the inner diameter dimension of the magnet insertion hole 9, thereby holding the permanent magnet 10 in the axial direction. Can be facilitated.
[0037]
Since the high-density member 6b is also formed of a laminated core (lamination of thin magnetic metal plates) like the rotor core 6a, the high-density member 6b is formed in the same progressive die as the rotor core 6a. The portion 6b can be manufactured, and a low-cost permanent magnet type motor with a reduced number of manufacturing steps can be provided.
[0038]
Further, by using the permanent magnet type motor, a compressor with low noise and high efficiency can be realized. Furthermore, by forming the high-density member portion 6b of the rotor 6 of the permanent magnet type motor with a laminated body, the manufacture of the permanent magnet type motor is facilitated, and the cost of the compressor can be reduced.
[0039]
In the first and second embodiments, the permanent magnet type motor increases the inertial force of the rotor 6 by providing the high-density member 6b made of a high-density material at the end of the rotor core 6a, thereby increasing the vibration and motor vibration. Efficiency can be improved by providing a characteristic configuration that reduces noise and at the same time eliminates the problems A, B, and C. However, at least one of the configurations that eliminates the problems A, B, and C has an efficiency Can be improved, and by providing more than one, higher efficiency can be improved.
In addition, by using such a permanent magnet type motor for a compressor, it is possible to obtain a highly efficient compressor that reduces vibration and noise and at the same time eliminates at least one of the problems A, B, and C. .
[0040]
【The invention's effect】
As described above, in the present invention, the permanent magnet type motor is provided with the high-density member portion made of the high-density member at the axial end of the rotor core portion, and the outer diameter of the high-density member portion is set outside the rotor core portion. Make it smaller than the diameter.
Thus, the inertia force of the rotor can be increased, and a highly efficient and low noise permanent magnet type motor can be realized.
Also, by using this permanent magnet type motor, the speed fluctuation of the rotor due to the pressure fluctuation occurring during the suction, compression and discharge processes of the compression mechanism can be reduced, vibration can be reduced, and the sealed container and The noise generated through the discharge pipe and the suction pipe can be suppressed, and a highly efficient compressor with reduced vibration and noise can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a compressor incorporating a permanent magnet type motor for driving a compressor according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view of the rotor of FIG.
FIG. 3 is a simplified diagram showing a compressor mechanism of the compressor of FIG. 1;
FIG. 4 is a conceptual diagram showing pressure fluctuation of a compressor.
FIG. 5 is a diagram showing a current waveform of a permanent magnet type motor.
FIG. 6 is a longitudinal sectional view of a compressor incorporating a permanent magnet type motor for driving a compressor according to a second embodiment of the present invention.
FIG. 7 is a cross-sectional view of a rotor core of the permanent magnet type motor of FIG. 6;
FIG. 8 is a cross-sectional view of a high-density member of the permanent magnet type motor of FIG. 6;
FIG. 9 is a cross-sectional view of another rotor core of the permanent magnet type motor of FIG. 6;
FIG. 10 is a cross-sectional view of another high-density member of the permanent magnet motor of FIG. 6;
[Explanation of symbols]
Reference Signs List 5 stator, 5a stator core, 6 rotor, 6a rotor core, 6b high-density member, 9 magnet insertion hole, 10 permanent magnet, 11 winding, 13 drive shaft.

Claims (6)

A rotor having a drive shaft, a rotor core in which a permanent magnet is inserted and fixed to the drive shaft penetrating the center, and integrally rotating; and a rotor core provided with a predetermined gap from an outer peripheral portion of the rotor core. A permanent magnet type motor having a stator core portion formed so as to surround the portion, and a stator provided with a winding.
A permanent magnet, wherein a high-density member made of a high-density member is provided at an axial end of the rotor core, and an outer diameter of the high-density member is smaller than an outer diameter of the rotor core. Magnet type motor. 2. The permanent magnet motor according to claim 1, wherein a high-density member made of a non-magnetic metal is provided at an axial end of the rotor core. A rotor having a drive shaft, a rotor core in which a permanent magnet is inserted and fixed to the drive shaft penetrating the center, and integrally rotating; and a rotor core provided with a predetermined gap from an outer peripheral portion of the rotor core. A permanent magnet type motor having a stator core portion formed so as to surround the portion, and a stator provided with a winding.
A high-density member made of a magnetic metal is provided at an axial end of the rotor core, and the high-density member and the magnet insertion hole of the rotor core, the outer dimensions corresponding to the axial direction in a cross section orthogonal to the respective axes. D3 ≦ D4, wherein D3 ≦ D4. The permanent magnet type motor according to claim 1 or 3, wherein the high-density member is formed by laminating thin metal plates. A rotor having a drive shaft, a rotor core in which a permanent magnet is inserted and fixed to the drive shaft penetrating the center, and integrally rotating; and a rotor core provided with a predetermined gap from an outer peripheral portion of the rotor core. A permanent magnet type motor having a stator core portion formed so as to surround the portion, and a stator provided with a winding.
A high-density member portion made of a high-density member is provided at an axial end of the rotor core portion, and the high-density member portion is formed by laminating a thin metal plate via an insulating film. Permanent magnet type motor. A compressor using the permanent magnet type motor according to any one of claims 1 to 5 as a motor of the compressor.

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