JP2008131687A - Self-initiating type permanent magnet synchronous motor and compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet synchronous motor capable of reducing vibration, noise and torque ripple by overcoming the restrictions in order to solve the problem that skew and stage skew is difficult to be applied to a self-initiating type permanent magnet synchronous motor due to the restrictions in its configuration and structure while the skew and the stage skew are applied to a rotor to reduce a spatial harmonics magnetic flux in an air gap due to a stator slot shape or a rotor shape, the magnetic flux is a factor of vibration, noise and torque ripple, and to provide a compressor using the same. <P>SOLUTION: In the self-initiating type permanent magnet synchronous motor provided with gaps and magnetic bodies in the circumferential direction between magnetic poles of permanent magnets, the gaps and the magnetic bodies are formed so as to be asymmetrical at center portions each extending in the radial direction of the magnetic poles of the permanent magnets as a boundary, and a laminate thickness of substantially half the axial direction is reverted using a center line extending the radial direction of the magnetic poles of the permanent magnets as an axis. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a self-starting permanent magnet synchronous motor and a compressor.

  An induction motor has been conventionally used as a drive source for a constant speed compressor that does not require speed control among compressors mounted on an electric refrigerator or an air conditioner. One of the performance requirements for the motor that is the compressor drive source is the reduction of vibration, noise, and torque pulsation caused by the space harmonic magnetic flux. In conventional induction motors, the rotor is skewed. That reduction has been realized.

  On the other hand, with the recent increase in needs for higher efficiency, development of a self-starting permanent magnet synchronous motor that can be self-started with a commercial power source and can realize high-efficiency operation is desired. However, the self-starting permanent magnet synchronous motor has a starting squirrel-cage conductor on the outer peripheral side of the rotor, and it is necessary to dispose the permanent magnet on the inner peripheral side of the squirrel-cage conductor. For this reason, it is difficult to apply the skew which has been performed by the conventional induction motor. Further, with respect to the method of applying step skew to the rotor as disclosed in Patent Document 1, there is a problem in the step of inserting a permanent magnet into the rotor, considering that the cage conductor is formed by die casting. . In other words, since it is structurally difficult to insert a permanent magnet into a rotor after die casting, it is desirable to insert it in advance before die casting. However, in such a case, the magnet characteristics deteriorate due to high temperature heating during die casting. End up.

JP 2006-60952 A

  As a generation factor of vibration, noise, and torque pulsation, spatial harmonic magnetic flux in the air gap due to the stator slot shape and the rotor shape can be mentioned. In order to reduce this, it is common to apply skew and step skew to the rotor, but it is difficult to apply the self-starting permanent magnet synchronous motor due to its structural and structural limitations.

  An object of the present invention is to provide a permanent magnet synchronous motor and its rotor, or a compressor using these, which can overcome the above limitations and reduce vibration, noise and torque pulsation.

  In the present invention, in the permanent magnet type synchronous motor including a hole and a magnetic body in the circumferential direction between the magnetic poles of the permanent magnet, the hole and the magnetic body are extended in the radial direction between the magnetic poles of the permanent magnet. It is configured so as to be asymmetrical with respect to a line, and a stack of about half of the axial thickness is reversed with the center line extending in the radial direction of the magnetic pole of the permanent magnet as the axis.

  According to the present invention, a self-starting permanent magnet synchronous motor and a compressor capable of reducing vibration, noise, and torque pulsation can be provided.

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

  FIG. 1 is a radial sectional view of a rotor of a self-starting permanent magnet synchronous motor according to a first embodiment of the present invention. In the figure, a rotor 1 includes a large number of squirrel cage windings 3 and a permanent magnet 4 mainly composed of a rare earth embedded in a magnet insertion hole 7 in a rotor core 2 provided on a shaft 6. Are arranged so that the number of poles is two. The gap between the magnetic poles of the permanent magnet 4 is composed of a hole 5 and a magnetic body 8, and the hole 5 and the magnetic body 8 are bounded by a center line A-A ′ extending in the radial direction between the magnetic poles of the permanent magnet 4. As shown in FIG. The magnetic body 8 may be configured by punching a silicon steel plate to form holes and then inserting iron or the like newly, or may be configured without punching the silicon steel plate. . The rotor core 2 may be a powder compact such as a dust core. Furthermore, the rotor core 2 and the permanent magnet 4 may be formed by integral molding.

  In the prior art, the rotor core shown in FIG. 1 was only laminated in the axial direction. However, in the present invention, as shown in FIG. The center line B-B 'extending in the direction is inverted and stacked, and the other half of the thickness X1 is stacked in the axial direction. Thereby, as shown in FIG. 3, torque pulsation can be reduced, and vibration and noise can be reduced without depending on skew and step skew.

  FIG. 4 is a radial sectional view of a rotor of a self-starting permanent magnet synchronous motor according to a second embodiment of the present invention. In FIG. 4, the same components as those in FIG. As shown in FIG. 4, the magnetic pulsation 8 between the magnetic poles is configured to be shifted by about 6 ° in electrical angle with respect to the center line A-A ′ extending in the radial direction between the magnetic poles of the permanent magnet 4. The reduction effect is maximum, and a large reduction effect can be obtained by setting the angle to 5 ° to 7 ° as shown in FIG.

  FIG. 5 is a radial sectional view of a rotor of a self-starting permanent magnet synchronous motor according to a fourth embodiment of the present invention. In FIG. 5, the same components as those in FIG. As shown in FIG. 5, a part of the cage-shaped winding 3 disposed between the magnetic poles of the permanent magnet 4 is disposed so as to form a deep groove on the radially inner peripheral side. The center line AA ′ extending in the radial direction between the four magnetic poles is configured to be asymmetrical with the boundary being approximately a half of the axial thickness Y1 as the center line extending in the radial direction of the magnetic pole of the permanent magnet 4. Laminate with BB 'as the axis. Even with this configuration, the same characteristics as those of the first embodiment can be obtained.

  FIG. 6 is a radial sectional view of a rotor of a self-starting permanent magnet synchronous motor according to a fifth embodiment of the present invention. In FIG. 7, the same components as those in FIG. The gap between the magnetic poles of the permanent magnet 4 is composed of a hole 5 and a magnetic body 8, and the hole 5 and the magnetic body 8 are bounded by a center line A-A ′ extending in the radial direction between the magnetic poles of the permanent magnet 4. As shown in FIG. As shown in FIG. 6, a half located in the middle portion excluding a quarter thickness X2 located in the upper part in the axial direction and a quarter thickness X3 located in the lower part. Only the thickness Y2 is laminated with the center line BB ′ extending in the radial direction of the magnetic pole of the permanent magnet 4 as the axis. Even if comprised in this way, the characteristic similar to 1st Example can be acquired, and the axial thrust force can be averaged. Here, assuming that the torque pulsation component before applying the skew is T, the pulsation component of Y1 and X1 becomes T / 2 and −T / 2 respectively by setting the skew as shown in FIG. The total is zero. Accordingly, in the case shown in FIG. 7 as well, the pulsating components of X2, Y2, and X3 are −T / 4, T / 2, and −T / 4, respectively, and the sum is zero. It can be seen that

  FIG. 7 is a sectional structural view of a compressor according to an embodiment of the present invention. In FIG. 7, the compression mechanism portion is formed by meshing a spiral wrap 15 standing upright on the end plate 14 of the fixed scroll member 13 and a spiral wrap 18 standing upright on the end plate 17 of the orbiting scroll member 16. . Then, the orbiting scroll member 16 is rotated by the crankshaft 6 to perform the compression operation.

Compression chamber 19 formed by fixed scroll member 13 and orbiting scroll member 16
(19a, 19b,...), The compression chamber 19 located on the outermost diameter side moves toward the center of the scroll members 13 and 16 along with the turning motion, and the volume gradually decreases.

  When both the compression chambers 19 a and 19 b reach the vicinity of the centers of the scroll members 13 and 16, the compressed gas in both the compression chambers 19 is discharged from a discharge port 20 communicating with the compression chamber 19. The discharged compressed gas passes through a gas passage (not shown) provided in the fixed scroll member 13 and the frame 21 and reaches the pressure vessel 22 below the frame 21, and a discharge pipe provided on the side wall of the pressure vessel 22. 23 is discharged out of the compressor. As described with reference to FIGS. 1 to 7, a permanent magnet synchronous motor 24 composed of the stator 9 and the rotor 1 is enclosed in the pressure vessel 22, rotates at a constant speed, and is compressed. Perform the action.

  An oil reservoir 25 is provided below the synchronous motor 24. Oil in the oil reservoir 25 passes through an oil hole 26 provided in the crankshaft 6 due to a pressure difference caused by rotational movement, and the sliding portion between the orbiting scroll member 16 and the crankshaft 6, the sliding bearing 27, etc. Used for lubrication.

  As described above, if the self-starting permanent magnet synchronous motor described with reference to FIGS. 1 to 7 is applied as the compressor driving motor, it is possible to reduce the vibration and noise of the constant speed compressor.

  According to the above embodiment, it is possible to provide a self-starting permanent magnet synchronous motor capable of reducing vibration, noise, and torque pulsation, a rotor thereof, and a compressor using these.

1 is a radial cross-sectional view of a rotor of a self-starting permanent magnet synchronous motor according to a first embodiment of the present invention. The axial direction lamination | stacking figure of the rotor of the self-starting-type permanent magnet synchronous motor by 1st Example of this invention. The figure which shows the torque pulsation reduction effect in 1st Example of this invention. The radial direction sectional view of the rotor of the self-starting type permanent magnet synchronous motor by the 2nd example of the present invention. The radial direction sectional view of the rotor of the self starting type permanent magnet synchronous motor by the 4th example of the present invention. The axial direction lamination | stacking figure of the rotor of the self-starting-type permanent magnet synchronous motor by the 5th Example of this invention. The cross-section figure of the compressor by one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotor core 3 Cage-type winding 4 Permanent magnet 5 Hole 6 Shaft or crankshaft 7 Magnet insertion hole 8 Magnetic body 9 Stator 10 Slot 11 Teeth 12 Armature winding 13 Fixed scroll members 14 and 17 End Plates 15 and 18 Spiral wrap 16 Orbiting scroll member 19 Compression chamber 20 Discharge port 21 Frame 22 Pressure vessel 23 Discharge pipe 24 Synchronous motor 25 Oil reservoir 26 Oil hole 27 Sliding bearing

Claims (12)

A stator provided with a stator winding, and a rotor that is rotatably supported on the inner peripheral side of the stator via a predetermined gap, on the outer periphery of the rotor core that constitutes the rotor A number of slots provided in the axial direction, a conductive bar embedded in the slot, a conductive end ring that short-circuits the bar at the end face in the axial direction, and a two-pole configuration embedded on the inner peripheral side of the bar In a self-starting permanent magnet synchronous motor comprising a permanent magnet and a hole and a magnetic body in a circumferential direction between the magnetic poles of the permanent magnet,
The hole and the magnetic body are configured to be asymmetric with a center line extending in the radial direction between the magnetic poles of the permanent magnet as a boundary, and a half of the axial thickness of the magnetic pole of the permanent magnet A self-starting permanent magnet synchronous motor characterized by being laminated with the center line extending in the radial direction as an axis.   2. The self-starting permanent magnet synchronous motor according to claim 1, wherein the asymmetrical operation is performed by shifting the electrical angle by about 6 [deg.] With respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet. 2. The self-starting permanent magnet synchronous motor according to claim 1, wherein the asymmetry is made by shifting the electrical angle by 5 ° to 7 ° with respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet.   2. The self-starting permanent magnet synchronous motor according to claim 1, wherein a part of the bar arranged between the magnetic poles is arranged as a deep groove on the radially inner peripheral side so as to be asymmetric. . A stator provided with a stator winding, and a rotor that is rotatably supported on the inner peripheral side of the stator via a predetermined gap, on the outer periphery of the rotor core that constitutes the rotor A number of slots provided in the axial direction, a conductive bar embedded in the slot, a conductive end ring that short-circuits the bar at the end face in the axial direction, and a two-pole configuration embedded on the inner peripheral side of the bar In a self-starting permanent magnet synchronous motor comprising a permanent magnet and a hole and a magnetic body in a circumferential direction between the magnetic poles of the permanent magnet,
The hole and the magnetic body are configured to be asymmetric with a center line extending in the radial direction between the magnetic poles of the permanent magnet as a boundary, and an axially lower thickness of about one quarter and an upper portion The intermediate portion excluding about one-fourth of the thickness of the intermediate portion is laminated by inverting the centerline extending in the radial direction of the magnetic pole of the permanent magnet as an axis. Self-starting permanent magnet synchronous motor.   6. The self-starting permanent magnet synchronous motor according to claim 5, wherein the asymmetrical motor is configured by shifting the electrical angle by approximately 6 degrees with respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet. 6. The self-starting permanent magnet synchronous motor according to claim 5, wherein the asymmetrical motor is shifted by 5 to 7 degrees in electrical angle with respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet.   6. The self-starting permanent magnet synchronous motor according to claim 5, wherein a part of the bar arranged between the magnetic poles is arranged as a deep groove on the radially inner peripheral side, thereby making the asymmetric. .   In a compressor including a compression mechanism section that sucks in, compresses and discharges refrigerant, and a drive motor that drives the compression mechanism section, the drive motor includes a stator including a stator winding, and a stator motor. A rotor that is rotatably supported on the inner peripheral side through a predetermined gap, and is provided with a number of slots provided in the axial direction on the outer peripheral portion of the rotor core that constitutes the rotor, and embedded in the slot A conductive end ring that short-circuits the bar at the axial end face, a two-pole permanent magnet embedded on the inner peripheral side of the bar, and a circumferential direction between the magnetic poles of the permanent magnet A hole and a magnetic body, and the hole and the magnetic body are configured to be asymmetric with a center line extending in a radial direction between the magnetic poles of the permanent magnet as a boundary, and approximately half of the axial direction. The accumulated thickness in the radial direction of the magnetic pole of the permanent magnet Compressor which is a self-starting permanent magnet synchronous motor configured by laminating by inverting the building center line as an axis.   10. The self-starting permanent magnet synchronous motor according to claim 9, wherein the asymmetrical motor is configured by shifting the electrical angle by approximately 6 degrees with respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet. 10. The self-starting permanent magnet synchronous motor according to claim 9, wherein the asymmetrical operation is performed by shifting the electrical angle by 5 ° to 7 ° with respect to a center line extending in a radial direction between the magnetic poles of the permanent magnet.   10. The self-starting permanent magnet synchronous motor according to claim 9, wherein a part of the bar arranged between the magnetic poles is arranged as a deep groove on the radially inner peripheral side, thereby making the asymmetrical. .

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