JP6416449B1 - Permanent magnet type rotating electric machine and compressor using the same - Google Patents

Abstract

An object of the present invention is to provide a permanent magnet type rotating electric machine that suppresses the generation of noise while suppressing a decrease in the efficiency of the electric motor, and a compressor using the permanent magnet type rotating electric machine.
Therefore, in this invention, it has the stator 2 and the rotor 3 arrange | positioned rotatably on the outer peripheral side of the stator 2, and the stator 2 is provided with two or more radially provided toward the radial direction outer side. Teeth 4, slots 7 formed between the plurality of teeth 4, and armature windings 8 wound around the plurality of teeth 4. The rotor 3 is provided with a plurality of permanent magnets 13. In the permanent magnet type rotating electrical machine, when the width of the opening of the slot 7 of the stator 2 is L1, the distance between the roots of the teeth 4 on the back side of the slot 7 is L2, and the width of the teeth is L3, L1 <L2 <L3 It was configured to be in the relationship.

Description

  The present invention relates to a permanent magnet type rotating electric machine and a compressor using the same.

  Permanent magnet type rotating electrical machines are applied to various technical fields such as compressors in air conditioners, refrigerators, freezers, food showcases and the like. Conventionally, in a permanent magnet type rotating electric machine, concentrated winding is adopted for the stator winding that is an armature winding, and a permanent magnet having a high magnetic flux density such as a neodymium magnet is adopted for the field magnet. Increased efficiency. However, with the increase in output density due to miniaturization and higher efficiency, the influence of the non-linear magnetic characteristics (hysteresis) of the iron core becomes remarkable, and the spatial harmonic magnetic flux increases in combination with the use of concentrated winding.

  In order to solve this problem, for example, Patent Document 1 proposes a technique in which the center of the stator tooth tip is concentric with the rotor core, and both ends of the tooth tip are linear, that is, away from the rotor. ing. Thereby, the harmonic magnetic flux in a gap surface is reduced.

Japanese Utility Model Publication No. 3-106869

  By adopting the concentrated winding stator and the high magnetic flux density magnet, the efficiency of the permanent magnet type rotating electrical machine has been dramatically improved. On the other hand, in the concentrated winding stator, in contrast to the distributed winding stator, the harmonic magnetic flux increases in principle, and the harmonic magnetic flux is promoted by a permanent magnet having a high magnetic flux density. That is, the non-linearity of the iron core increases with the increase in output density due to the miniaturization and high efficiency, and the vibration and noise of the permanent magnet type rotating electrical machine itself are also increasing. In particular, when incorporated in a compressor, there is a problem that the middle frequency band, which is most disturbing, becomes obvious.

  On the other hand, in Patent Document 1, the center of the stator tooth tip is concentric with the rotor core, and both ends of the tooth tip are linear, that is, away from the rotor, thereby reducing the harmonic magnetic flux in the gap surface. ing. As a result, the induced electromotive force waveform can be made into a sine wave to make the armature current into a sine wave, the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current can be reduced, and the pulsating torque caused by vibration and noise Radial electromagnetic excitation force is reduced.

  However, in the technique described in Patent Document 1, although noise generated in a relatively low frequency band and a relatively high frequency band can be reduced, it can be reduced for noise in a middle frequency band. There wasn't. As the reason, in the case of Patent Document 1, the slot cross-sectional area decreases as the both ends of the tooth tip end away from the rotor, and the armature winding cannot be inserted, so that the performance such as permanent magnet type rotating electrical machine efficiency is lowered. This is because there is a limit to reducing the harmonic component of the in-machine magnetic flux without any problems.

  Here, in order to reduce the noise of the compressor, it is necessary to reduce the vibration of the motor itself or to prevent the vibration of the motor from being transmitted to the frame of the compressor. In order to reduce the vibration of the electric motor, it is considered effective to reduce the harmonic component of the in-machine magnetic flux and reduce the pulsating torque and the radial electromagnetic excitation force as described above.

  On the other hand, in order to prevent the vibration of the motor from being transmitted to the frame of the compressor, it is considered that a motor structure and a fixing method having a function of attenuating vibration factors are effective.

  Therefore, in order to reduce the compressor efficiency and noise, the harmonic component in the in-machine magnetic flux is sufficiently reduced in consideration of the armature reaction, and the in-machine pulsation torque and radial electromagnetic excitation force are reduced. It is very important to make the stator core shape difficult to be transmitted to the frame, and it has been found that there are optimum configurations for the rotor structure and the stator structure depending on the operating conditions of the motor to be driven.

  An object of the present invention is to solve the above problems and provide a permanent magnet type rotating electrical machine that suppresses the generation of noise while suppressing a decrease in the efficiency of the electric motor and a compressor using the same.

In order to achieve the above object, the present invention is characterized by having a stator and a rotor rotatably arranged on the outer peripheral side of the stator, and the stator is radially outward from the center. A plurality of teeth provided radially toward the plurality of slots, a slot formed between the plurality of teeth, and an armature winding wound around the plurality of teeth. In the permanent magnet type rotating electrical machine in which the magnet is disposed, when the slot opening width of the stator is L1, the distance between the teeth roots on the back side of the slot is L2, and the width of the teeth is L3, The rotor is configured to have a relation of L1 <L2 <L3, and the rotor is formed with a recess recessed radially outward from the inner peripheral surface of the rotor, and the magnetic flux axis of the permanent magnet is a d-axis. , Orthogonal to the d-axis in electrical angle Is the q-axis, the recesses are positioned on the q-axis, the plurality of permanent magnets are arranged to extend in the circumferential direction of the rotor, and the recesses have a circumferential length of the permanent magnets. It is comprised from the two linear parts along a direction, and the curved part formed between the two said linear parts .

Further, the present invention is characterized by a compression mechanism for compressing the working fluid, a permanent magnet type rotating electrical machine that drives the compression mechanism, and a compression container that houses the compression mechanism and the permanent magnet type rotating electrical machine. The permanent magnet type rotating electrical machine includes a stator and a rotor rotatably disposed on an outer peripheral side of the stator, and the stator is radially outward from the center. And a plurality of teeth provided radially, a slot formed between the plurality of teeth, and an armature winding wound around the plurality of teeth, wherein the rotor includes a plurality of permanent magnets. Is arranged, and the slot opening width of the stator is L1, the distance between the tooth roots on the back side of the slot is L2, and the width of the teeth is L3, the relation of L1 <L2 <L3 is satisfied. Configure to be The rotor recess recessed radially outward from the inner peripheral surface of the rotor is formed in the magnetic flux axis of the permanent magnet and the d-axis, an axis perpendicular with the d-axis and the electrical angle q When the shaft is used, the concave portion is positioned on the q-axis, the plurality of permanent magnets are arranged so as to extend in the circumferential direction of the rotor, and the concave portion is arranged in the circumferential length direction of the permanent magnet. There are two straight portions along the line and a curved portion formed between the two straight portions .

  ADVANTAGE OF THE INVENTION According to this invention, the permanent magnet type rotary electric machine which suppressed generation | occurrence | production of noise, suppressing the fall of the efficiency of an electric motor, and a compressor using the same can be provided.

It is sectional drawing of the permanent magnet type rotary electric machine which concerns on Example 1 of this invention. It is sectional drawing which shows the rotor core shape of the permanent magnet type rotary electric machine which concerns on Example 1 of this invention. It is a principal part enlarged view of the stator core which concerns on Example 1 of this invention. It is sectional drawing of the compressor which concerns on Example 2 of this invention. It is a figure which shows the audibility test result of the compressor in various rotary electric machine structures. It is sectional drawing which shows the rotor core shape of the permanent magnet type rotary electric machine which concerns on Example 3 of this invention. It is sectional drawing of the permanent-magnet-type rotary electric machine which concerns on a comparative example.

  Embodiments of the present invention will be described below with reference to FIGS. In each figure, the same reference numerals indicate the same constituent elements or constituent elements having similar functions. Further, the permanent magnet type rotating electrical machine of each embodiment is composed of a rotor having 6 poles (4 poles in FIG. 7) and a stator having 9 slots (6 slots in FIG. 7). That is, the ratio of the number of rotor poles to the number of stator slots is 2: 3. The number of rotor poles, the number of stator slots, and the ratio thereof are not limited to the values in each embodiment, and other values can provide the same effects as those in each embodiment. For example, the number of poles of the rotor may be 4 poles, 8 poles, 10 poles, or the like. The permanent magnet type rotating electric machine in each embodiment is a so-called embedded magnet type rotating electric machine in which a permanent magnet is embedded in a rotor core.

  In the following description, “axial direction” indicates the rotational axis direction of the rotor, “radial direction” indicates the radial direction of the rotor, and “circumferential direction” indicates the circumferential direction of the rotor.

  FIG. 1 is a cross-sectional view of a permanent magnet type rotating electrical machine that is Embodiment 1 of the present invention. This sectional view shows a section in a direction perpendicular to the rotation axis (the same applies to the drawings described later). The first embodiment operates as a permanent magnet type synchronous motor. In addition, the first embodiment will be described with an example having an abduction type rotor.

  As shown in FIG. 1, the permanent magnet type rotating electrical machine 1 includes a stator 2 and a rotor 3 disposed outside the stator 2 via a predetermined gap (gap). The rotor 3 is provided with a rotor support member (not shown) having a shaft fixing portion. The stator 2 includes an annular core back 5 and a plurality of teeth 4 projecting radially outward from the core back 5. The plurality of teeth 4 are arranged at substantially equal intervals along the circumferential direction. A slot 7 is formed between the teeth 4 adjacent to each other in the circumferential direction, and an armature winding 8 that is concentratedly wound so as to surround the teeth 4 is provided. The armature winding 8 is wound around the axial center of the teeth 4 arranged radially in the radial direction, and in the circumferential direction, a U-phase winding 8a, a V-phase winding 8b, and a W-phase winding of a three-phase winding are provided. 8c are mutually arrange | positioned through a space | gap.

  Here, in the permanent magnet type rotating electrical machine 1, since the number of poles of the rotor 3 is 6 and the number of slots of the stator 2 is 9 slots, the slot pitch is 120 degrees in electrical angle. A shaft hole 15 that penetrates a cylindrical shaft (not shown) is formed at the center of the stator 2.

  In the permanent magnet type rotating electrical machine 1 of the first embodiment, a three-phase alternating current is applied to the armature winding 8 composed of three-phase windings (U-phase winding 8a, V-phase winding 8b, W-phase winding 8c). When flowing, a rotating magnetic field is generated. The rotor 3 is rotated by the electromagnetic force acting on the permanent magnet 14 and the rotor core 12 by the rotating magnetic field.

  In order to reduce iron loss such as eddy current loss generated in the stator core 6 and the rotor core 12 when the permanent magnet type rotating electrical machine 1 is operated, the stator core 6 and the rotor core 12 are made of silicon steel plates. It is preferable to comprise a laminated body in which a plurality of thin plates made of magnetic steel plates are laminated.

  FIG. 2 is a cross-sectional view illustrating the rotor core shape of the permanent magnet type rotating electrical machine 1 according to the first embodiment. In FIG. 2, the rotor 3 is configured by laminating a rotor core 12. In the vicinity of the inner peripheral surface of the rotor core 12, a plurality of rectangular permanent magnet insertion portions 13 (six in the first embodiment, which is the number of poles) are formed.

  Flat permanent magnets 14 made of a magnet material, for example, rare earth neodymium, are inserted into the plurality of permanent magnet insertion portions 13. The permanent magnet insertion portion 13 is formed slightly larger than the permanent magnet 14, and the outer periphery of the permanent magnet 14 is covered with the rotor core 12. The permanent magnet 14 moves through the gap of the permanent magnet insertion portion 13 due to acceleration / deceleration accompanying the rotation of the rotor 3. However, since the periphery is covered with the rotor core 12, the load acting on the permanent magnet 14 is permanent. It is received by the surface of the rotor core 12 in the magnet insertion part 13. For this reason, there is no possibility of cracks or the like in the rotor core 12 itself. Moreover, since the permanent magnet 14 also contacts the surface of the rotor core 12 in the permanent magnet insertion portion 13, there is no possibility that the permanent magnet 14 is damaged.

  Here, in the rotor cross section of FIG. 2, the direction of the magnetic flux generated by the magnetic pole of the permanent magnet 14, that is, the virtual axis connecting the longitudinal center (cross section center) of the permanent magnet 14 and the rotation center O is the d axis (flux axis). And an axis that is electrically perpendicular to the d-axis, that is, an electrical angle (an axis between permanent magnets) is defined as a q-axis.

  In FIG. 2, the rotor core 12 is provided with one permanent magnet 14 per magnetic pole. The cross-sectional shape of the permanent magnet 14 is an elongated rectangular shape like the permanent magnet insertion portion 13, and its longitudinal direction extends in a direction perpendicular to the d-axis geometrically. The plurality of permanent magnets 14 are arranged so as to extend in the circumferential direction of the rotor 3.

  The rotor core 12 of the rotor 3 is recessed outwardly in the radial direction from the inner peripheral surface of the rotor 3 on the q axis between adjacent permanent magnet insertion portions 13 (between the poles of the permanent magnet 14). A recess 11 is provided. The recess 11 suppresses the q-axis magnetic flux as will be described later. Further, the rotor 3, that is, the rotor core 12, is located on the inner peripheral side with respect to the recess 11, and the gap length (gap) between the stator 2 and the teeth 4 is the shortest g 1, and the gap length is and an inner peripheral portion that becomes g2 longer than g1.

  Next, the configuration of the recess 11 will be described. The concave portion 11 includes two straight portions 11b and 11c that are parallel to the circumferential direction (length direction) of the permanent magnet 14, and a curved portion 11a that connects the end portions on the rotor inner circumferential side of the two straight portions. Yes. Thus, by providing a curved part in the recessed part 11, the influence of the stress accompanying a rotor centrifugal force can be relieved in a high speed region. In the concave portion 11 of the first embodiment, the curved portion 11a is smoothly connected to the two straight portions 11b and 11c. As a result, stress concentration associated with the rotor centrifugal force in the recess 11 is alleviated, so that the strength of the rotor against the centrifugal force is improved. Further, in the direction perpendicular to the q axis, the interval between the two straight portions 11 b and 11 c of the recess 11 is widened from the outer peripheral side of the rotor 3 toward the inner peripheral side of the rotor 3.

  Around the rotation center O of the rotor 3, the angle between the end portions of the inner peripheral side magnetic pole surface of the permanent magnet 14 constituting one magnetic pole of the rotor 3 is θp1, and the two linear portions 11b and 11c of the recess 11 are When the angle between the end portions on the outer periphery side of the rotor (curved portion 11a) is θp2 (opening angle of the permanent magnet 14), θp1 and θp2 satisfy the relationship of 0.18 ≦ θp2 / θp1 ≦ 0.5. Is set as follows.

  Here, in the present embodiment, as described above, the slot pitch in the stator having concentrated windings is 120 ° in electrical angle. Further, since there are 1.5 slots per magnetic pole (= 9 slots / 6 poles), the angle between the q axes is 180 ° in electrical angle. Therefore, the electrical angle is 120 ° ≦ θp1 <180 ° and 0 ° <θp2 ≦ 60 °. Therefore, 0 <θp2 / θp1 ≦ 0.5 (= 60 ° / 120 °). In the first embodiment, the lower limit value is set to 0.18 so as to satisfy the relationship of 0.18 ≦ θp2 / θp1 ≦ 0.5.

  Further, in the case of the rotor provided with the concave portion 11 having the curved portion as in the first embodiment, a substantial torque improvement effect by suppressing the q-axis magnetic flux can be obtained by setting 0.18 ≦ θp2 / θp1. .

  The rotor core 12 of the rotor 3 of the first embodiment is recessed from the inner peripheral surface of the rotor toward the radially outer side between the adjacent permanent magnet insertion portions 13 (between the poles of the permanent magnet 14). A recess 11 is provided. And the recessed part 11 is located on the q-axis. Since the air layer is formed by the recess 11 and the magnetic resistance is increased by the air layer, it is difficult for the magnetic flux to pass between the permanent magnet insertion portions 13 (permanent magnets 14) adjacent in the circumferential direction. For this reason, the leakage magnetic flux from between the permanent magnets 14 can be reduced, the influence of the q-axis magnetic flux can be suppressed, and the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current can be reduced. That is, the recess 11 suppresses the armature reaction and reduces the harmonic component of the in-machine magnetic flux.

  Next, a configuration for further enhancing the effect of the first embodiment will be described. The rotor 3 includes a notch portion 17 formed between the permanent magnet insertion portions 13 (permanent magnets 14) adjacent to each other in the circumferential direction and isolated from the permanent magnet insertion portion 13. This notch 17 penetrates the rotor in the axial direction. The notch 17 can reduce the leakage magnetic flux of the permanent magnet, suppress the influence of the q-axis magnetic flux, and can reduce the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current. That is, the notch portion 17 suppresses the armature reaction and reduces the harmonic component of the in-machine magnetic flux. Further, since the outer periphery of the permanent magnet 14 embedded in the permanent magnet insertion portion 13 is covered with the rotor core 12, the permanent magnet 14 passes through the gap of the permanent magnet insertion portion 13 due to acceleration / deceleration accompanying the rotation of the rotor 3. Even if it moves, there is no fear of cracks or the like in the rotor core 12 itself, and neither the permanent magnet 14 nor the permanent magnet 14 is damaged.

  By the way, in the permanent magnet type rotating electrical machine 1 for a compressor which is the subject of the present invention, vibration and noise often become a problem. In particular, the concentrated winding armature winding 8 has a 120-degree winding arrangement, so that the harmonic components such as the fifth and seventh orders of the in-machine magnetic flux are large, and the pulsating torque and radial electromagnetic excitation that cause vibration and noise. Power also increases.

  Therefore, vibration and noise factors will be described using a comparative example similar to Patent Document 1. FIG. 7 is a cross-sectional view of a permanent magnet type rotating electrical machine according to a comparative example. FIG. 7 shows an example provided with an inward-rotor. The center portion of the tooth tip portion 25 of the stator 2 is concentric with the rotor core 12 so that both ends of the tooth tip portion 25 are linear, that is, away from the rotor 3. With such a structure, the induced electromotive force waveform can be converted into a sine wave, and the armature current can be converted into a sine wave, and the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current can be reduced. Electromagnetic excitation force is reduced.

  However, since the cross-sectional area of the slot 7 decreases as the both ends of the tooth tip 25 are moved away from the rotor 3, the diameter of the element wire of the armature winding 8 disposed in the slot 7 is reduced, or the electric machine There arises a problem that the number of turns of the child winding 8 must be reduced. Therefore, in order to prevent a reduction in efficiency, both ends of the tooth tip 25 cannot be moved away from the rotor 3 until vibration and noise are sufficiently reduced.

  Furthermore, since the stator iron core 6 is fixed by the arcuate portion in the vicinity of the core back 5 at the contact portion between the compressor frame and the stator 2 by shrink fitting or press fitting, the vibration of the motor is easily transmitted to the compressor frame. The vibration and noise of the compressor cannot be reduced sufficiently.

  Therefore, in the first embodiment, as shown in FIG. 1, there is provided an outer rotation type rotor in which an inner peripheral portion of the teeth 4 of the stator core 6 and an exclusive frame (not shown) are in contact and fixed. The permanent magnet type rotating electrical machine 1 is used so that the vibration of the motor is not transmitted to the frame of the compressor.

  Furthermore, the detailed structure of the stator core 6 will be described with reference to FIG. FIG. 3 is an enlarged view of a main part of the stator core according to the first embodiment of the present invention. In FIG. 3, in Example 1, when the opening width of the slot 7 of the stator 2 is L1, the distance between the roots of the teeth on the back side of the slot 7 is L2, and the width of the teeth is L3, L1 <L2 < It is configured to have a relationship of L3. Further, in order to ensure the effective cross-sectional area of the slot 7, the depth L4 of the slot 7 is made shorter than the length L5 of the tooth 4 (L4 <L5) so as to suppress the reduction of the motor efficiency as much as possible. The depth L4 of the slot 7 refers to the distance from the outermost periphery of the tooth 4 in the slot 7 to the root of the tooth 4 on the back side of the slot 7. The length L5 of the teeth 4 refers to the distance from the outermost periphery of the teeth 4 to the root of the teeth 4 at the center in the width direction of the teeth 4. In the stator 2 having the plurality of teeth 4 protruding outward in the radial direction from the core back 5 as in the first embodiment, the internal space of the slot 7 extends from the opening of the slot 7 and then radially It becomes narrower toward the inside. For this reason, when the armature winding 8 is wound around the slot 7, the armature winding 8 is difficult to enter the back side of the slot 7. Therefore, in this embodiment, the armature winding 8 is disposed on the back side of the slot 7, and the relationship between the depth L4 of the slot 7 and the length of the teeth 4 is defined so that the effective sectional area of the slot 7 can be secured. .

  According to the first embodiment, the harmonic component of the in-machine magnetic flux can be reduced, and the pulsation torque and radial electromagnetic excitation force in the machine transmitted to the compressor frame can be suppressed. A noiseless permanent magnet type rotating electrical machine and a compressor can be provided.

  Next, an example in which the permanent magnet type rotating electrical machine of the first embodiment is applied to a compressor will be described with reference to FIG. FIG. 4 is a cross-sectional view of a compressor according to a second embodiment of the present invention. In FIG. 4, an example of a scroll compressor will be described.

  In FIG. 4, the compression container 69 includes a cylindrical tube portion 69a, and an upper cover 69b and a bottom cover 69c disposed above and below the tube portion 69a. The compression container 69 includes a compression mechanism in which a spiral wrap 62 standing upright on the end plate 61 of the fixed scroll member 60 and a spiral wrap 65 standing upright on the end plate 64 of the orbiting scroll member 63 mesh with each other, and a permanent magnet. As the orbiting scroll member 63 orbits through the crankshaft 72 by the rotary electric machine, the working fluid is compressed. The orbiting scroll member 63 is supported by the frame 68. The frame 68 is fixed to the compression container 69. A suction pipe 76 is connected to the upper lid 69b of the compression container 69 to supply refrigerant gas into the compression chamber. As the permanent magnet type rotating electric machine, the first embodiment described above is applied.

  Of the compression chambers 66 a to 66 b formed by the fixed scroll member 60 and the orbiting scroll member 63, the compression chamber located on the outermost side is the orbiting scroll member 63 and the fixed scroll member 60 along with the orbiting motion. The volume gradually decreases. When the compression chambers 66 a and 66 b reach the vicinity of the center of the fixed scroll member 60 and the orbiting scroll member 63, the compressed gas that is the working fluid in both the compression chambers is discharged from the discharge port 67 communicating with the compression chamber 66. The discharged compressed gas is provided in the fixed scroll member 60 and the frame 68, passes through a gas passage (not shown), reaches the compression container 69 below the frame 68, is provided on the side wall of the compression container 69, and is supplied to the discharge pipe 70. From the compressor.

  Moreover, the permanent magnet type rotating electrical machine that drives the compressor is controlled by a separate inverter (not shown) and rotates at a rotation speed suitable for the compression operation. Here, the permanent magnet type rotating electrical machine includes the stator 2 and the rotor 3, and the crankshaft 72 is attached to the shaft hole 15 in the first embodiment. When the crankshaft 72 is rotated by the permanent magnet type rotating electrical machine, the orbiting scroll member 63 does not rotate, but performs orbiting and revolving motion having a predetermined eccentric amount at the upper portion of the crankshaft 72 as a radius. An oil hole 74 is provided in the crankshaft 72, and as the crankshaft 72 rotates, the lubricating oil in the oil reservoir 73 at the lower part of the compression container 69 is supplied to the slide bearing 75 through the oil hole 74. The

  Although not shown, the stator 2 of the present embodiment is fixed to the frame 68 with bolts or the like. Further, the boss portion of the frame 68 may be extended downward, and the center portion of the stator 2 may be press-fitted and fixed to the boss portion.

  A permanent magnet type rotating electrical machine having various rotor shapes and stator shapes was incorporated into such a compressor, and a noise audibility test was performed. The actual measurement result is shown in FIG.

  FIG. 5 is a diagram showing the audibility test results of the compressor in various rotating electrical machine structures. Generally, the human audible frequency is 20 Hz to 20000 Hz. In FIG. 5, the frequency band of annoying noise is roughly divided into three regions, a low region, a middle region, and a high region, and it has been found that particularly the middle region component appears more prominently. In this embodiment, the low frequency is about 100 Hz or less, the high frequency is 10,000 Hz or more, and the middle frequency is less than 100 to 10,000 Hz. The human ear has the highest sensitivity in the vicinity of 2000 Hz to 5000 Hz, and it is preferable to reduce the frequency component in the middle range.

  Analyzing the relationship between these noise frequency bands and various rotating electrical machine structures, the comparative example (the structure of the permanent magnet type rotating electrical machine shown in FIG. 7) has a reduction effect on the noise components in the low and high frequencies. However, although there was a slight change in the audibility in the middle range, it could not be reduced sufficiently.

  On the other hand, in the case of the structure of the present embodiment (a structure in which the rotor cross section shown in FIG. 2 and the stator cross section shown in FIG. 3 are combined), the noise components in the low and high frequencies have the same effect as the comparative example. In addition to the above, it was confirmed that the noise components in the middle range were greatly reduced. The noise in the middle range was 64.3 dB in this example compared to 67.4 dB in the comparative example. Therefore, when the noise generation factor was analyzed, in the structure of the comparative example, as the harmonic component of the in-machine magnetic flux, the lower order harmonic components such as the fifth order and the seventh order, and the relatively higher order components such as the 25th order and the 27th order components. It was observed that the harmonic components were greatly reduced. However, relatively high-frequency harmonic components such as 11th-order, 13th-order components, 15th-order, and 17th-order components have not been reduced as harmonic components of the in-machine magnetic flux.

  On the other hand, in the case of the structure of this example, as with the structure of the comparative example, the low and high order harmonic components of the in-machine magnetic flux are reduced, and the relatively high frequency harmonic component is significantly larger than the structure of the comparative example. It was found that it was reduced. As a reason for this, in the case of the structure of the present embodiment, it is possible to sufficiently reduce the harmonic component of the in-machine magnetic flux and to suppress the in-machine pulsation torque and the radial electromagnetic excitation force transmitted to the compressor frame. Because.

  By the way, in many current home and commercial air conditioners, the R410A refrigerant is sealed in the compression container 69, and the ambient temperature of the permanent magnet type rotating electric machine is often 80 ° C. or more. In the future, as the adoption of R32 refrigerant having a smaller global warming potential proceeds, the ambient temperature further increases. The permanent magnet 14, especially the neodymium magnet, decreases the residual magnetic flux density at high temperatures and increases the armature current in order to ensure the same output. Thus, efficiency reduction can be suppressed. In addition, in applying the permanent magnet type rotary electric machine of Example 1 to the compressor of Example 2, the type of refrigerant is not limited. The compressor may be a scroll compressor shown in FIG. 4 or a compressor having another compression mechanism such as a rotary compressor.

  According to the second embodiment, a compressor capable of saving energy can be realized by applying a small and highly efficient permanent magnet type rotating electrical machine. In addition, by applying the permanent magnet type rotating electric machine according to the first embodiment, the operating range can be expanded, for example, the compressor can be operated at high speed.

  Furthermore, in refrigerants such as He and R32, leakage from gaps in the compressor is larger than refrigerants such as R22, R407C, and R410A, and the ratio of leakage to the circulation rate is large particularly during low-speed operation. Decreases. In order to improve the efficiency at the time of low circulation (low speed operation), it is effective to reduce the leakage loss by miniaturizing the compression mechanism and securing the same circulation by increasing the rotation speed. Furthermore, it is preferable to increase the maximum rotational speed in order to ensure the maximum circulation amount.

  On the other hand, by applying the permanent magnet type rotating electrical machine 1 of the first embodiment described above to the compressor, it is possible to increase the maximum torque and the maximum rotational speed, and it is possible to reduce the loss in the high speed range. Therefore, the efficiency can be improved when using a refrigerant such as He or R32.

  According to the second embodiment, a small, high-efficiency, low-noise compressor can be provided by applying the permanent magnet type rotating electric machine of the first embodiment to various compressors for air conditioning.

  Next, Example 3 will be described with reference to FIG. FIG. 6 is a cross-sectional view of the rotor core shape of the permanent magnet type rotating electric machine according to the third embodiment of the present invention.

  In FIG. 6, the same reference numerals as those in FIG. 2 indicate the same constituent elements or constituent elements having similar functions. Hereinafter, points different from the first embodiment will be mainly described.

  In the third embodiment, unlike the first embodiment (FIG. 2), two permanent magnets are provided for each pole of the rotor. The rotor structure arranged in this way can sufficiently reduce harmonic components due to the effect of armature reaction, reduce pulsation torque and radial electromagnetic excitation force, and achieve small size, high efficiency and low noise. It goes without saying that you can do it. Therefore, even if it arrange | positions in this way, the effect similar to FIG. 2 can be acquired.

  Further, when a permanent magnet is used as in the first embodiment, heat loss due to eddy current becomes a problem. In particular, when performing high rotation, the frequency and fluctuation range of the fluctuating magnetic field applied to the magnet increase, and the heat loss increases accordingly. In order to reduce the heat loss due to this eddy current, the permanent magnet 14 embedded in the permanent magnet insertion portion 13 is divided and arranged in this embodiment (14a, 14b). In the divided permanent magnets 14a and 14b, the magnetic flux linked to the individual magnets is reduced. Therefore, the eddy current density of each of the divided permanent magnets 14a and 14b is reduced, and the eddy current loss as a total amount is reduced.

  According to the third embodiment, since the permanent magnets 14 (14a, 14b) embedded in the permanent magnet insertion portion 13 are divided and arranged, loss due to eddy current can be reduced.

  In addition, according to the second embodiment, the concave portion 11 is provided between the adjacent permanent magnet insertion portions 13 (between the poles of the permanent magnet 14). Since the recess 11 is positioned on the q-axis, the power factor decrease due to the influence of the armature reaction is suppressed, and the torque decrease in the high speed range can be suppressed.

  Furthermore, according to the third embodiment, a notch portion 17 is provided between the adjacent permanent magnet insertion portions 13 (between the poles of the permanent magnet 14), and is formed so as to be isolated from the permanent magnet insertion portion 13. Since the portion 17 is positioned on the q-axis, the power factor decrease due to the influence of the armature reaction is suppressed, and the torque decrease in the high speed range can be suppressed. For this reason, the permanent magnet type rotating electrical machine can be made highly efficient and downsized.

  Even in the rotor structure in which the permanent magnets 14 are divided and arranged as described above, it is possible to improve the power factor reduction due to the influence of the armature reaction, suppress the torque reduction, and reduce the size and increase the efficiency. Absent.

  According to the third embodiment, the efficiency of the compressor can be improved by applying the above-described permanent magnet type rotating electrical machine to the compressor.

  In addition, this invention is not limited to the Example mentioned above, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 Permanent magnet type rotary electric machine, 2 Stator, 3 Rotor, 4 Teeth, 6 Stator iron core, 7 slots, 8 Armature winding, 8a U phase winding, 8b V phase winding, 8c W phase winding, 11 concave portion, 11a curved portion, 11b linear portion, 11c linear portion, 12 rotor core, 13 permanent magnet insertion portion, 14 permanent magnet, 14a permanent magnet, 14b permanent magnet, 15 shaft hole, 17 notch portion, 25 teeth tip portion , 60 fixed scroll member, 61 end plate, 62 spiral wrap, 63 orbiting scroll member, 64 end plate, 65 spiral wrap, 66 compression chamber, 66a compression chamber, 66b compression chamber, 67 discharge port, 68 frame, 69 compression Container, 69a cylinder, 69b top lid, 69c bottom lid, 70 discharge pipe, 72 crankshaft, 73 oil reservoir, 74 oil hole, 75 slide bearing, 6 suction pipe

Claims (8)

A stator, and a rotor rotatably arranged on the outer peripheral side of the stator,
The stator includes a plurality of teeth provided radially outward from the center, slots formed between the plurality of teeth, and armature windings wound around the plurality of teeth. And
In the permanent magnet type rotating electrical machine in which a plurality of permanent magnets are arranged in the rotor,
When the width of the slot opening of the stator is L1, the distance between the teeth roots on the back side of the slot is L2, and the width of the teeth is L3, the relationship is L1 <L2 <L3 and,
The rotor is formed with a recess that is recessed radially outward from the inner peripheral surface of the rotor,
When the magnetic flux axis of the permanent magnet is a d-axis and the axis orthogonal to the d-axis in terms of electrical angle is the q-axis, the recess is positioned on the q-axis,
The plurality of permanent magnets are arranged to extend in the circumferential direction of the rotor,
The concave portion is composed of two linear portions along the circumferential length direction of the permanent magnet and a curved portion formed between the two linear portions. . In claim 1,
A permanent magnet type rotating electrical machine characterized by having a relationship of L4 <L5 when the slot depth is L4 and the tooth length is L5. In claim 1 ,
The angle θp1 between the end portions of the magnetic pole surface on the inner peripheral side of the permanent magnet and the angle θp2 between the end portions on the inner peripheral side of the rotor of the two linear portions are 0.18 ≦ θp2 / θp1 A permanent magnet type rotating electrical machine having a relationship of ≦ 0.5. In claim 1 ,
The permanent magnet-type rotating electrical machine, wherein the recess has an interval between the two linear portions that extends from the outer peripheral side of the rotor toward the inner peripheral side of the rotor. In claim 1,
The permanent magnet type rotating electrical machine, wherein the rotor includes a notch portion between the permanent magnets adjacent to each other in the circumferential direction of the rotor, and the notch portion is positioned on the q axis. In claim 1,
The permanent magnet type rotating electrical machine, wherein the permanent magnet is divided and arranged. In a compressor comprising: a compression mechanism for compressing a working fluid; a permanent magnet type rotating electrical machine that drives the compression mechanism; and a compression container that houses the compression mechanism and the permanent magnet type rotating electrical machine.
The permanent magnet type rotating electrical machine is:
A stator, and a rotor rotatably arranged on the outer peripheral side of the stator,
The stator includes a plurality of teeth provided radially outward from the center, slots formed between the plurality of teeth, and armature windings wound around the plurality of teeth. And
A plurality of permanent magnets are disposed on the rotor,
When the slot opening width of the stator is L1, the distance between the teeth roots on the back side of the slot is L2, and the width of the teeth is L3,
Configure so that L1 <L2 <L3 ,
The rotor is formed with a recess that is recessed radially outward from the inner peripheral surface of the rotor,
When the magnetic flux axis of the permanent magnet is a d-axis and the axis orthogonal to the d-axis in terms of electrical angle is the q-axis, the recess is positioned on the q-axis,
The plurality of permanent magnets are arranged to extend in the circumferential direction of the rotor,
The said recessed part was comprised from the two linear parts along the circumferential length direction of the said permanent magnet, and the curved part formed between the said two linear parts, The compressor characterized by the above-mentioned. In claim 7 ,
The compression mechanism includes a fixed scroll member, a orbiting scroll member that meshes with the fixed scroll member and is driven by the permanent magnet type rotating electrical machine, and a frame that supports the orbiting scroll member,
The frame is fixed to the compression container;
The stator compressor, characterized in that fixed to the frame.

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