WO2018096887A1

WO2018096887A1 - Permanent magnet type rotary electric machine and compressor using same

Info

Publication number: WO2018096887A1
Application number: PCT/JP2017/039503
Authority: WO
Inventors: 高畑　良一; 隆雅足立; 泰典中野; 中村　聡
Original assignee: 日立ジョンソンコントロールズ空調株式会社
Priority date: 2016-11-28
Filing date: 2017-11-01
Publication date: 2018-05-31
Also published as: CN109923757B; TW201834359A; JP2018088746A; CN109923757A; JP6381613B2; TWI655828B

Abstract

The purpose of the present invention is to obtain a compact and low-noise permanent magnet type rotary electric machine having high efficiency. The permanent magnet type rotary electric machine is provided with: a stator core having multiple teeth and slots; a stator having armature windings; a rotor core; and a rotor having multiple permanent magnets embedded in the rotor core. The stator is provided with arc sections to be fixed to a frame and stator recess sections formed on the outer peripheral side. The stator recess section is formed into a substantially trapezoidal shape formed by first and second straight parts connected to the arc sections and disposed parallel to the width direction of the tooth, a third straight part formed on the radial inner side and disposed parallel to the width direction of the tooth, and fourth and fifth straight parts connecting the third straight part with the first and second straight parts. When the distance between both slot-inner-side ends of a tooth tip part is defined as L1, the width of a tooth is defined as L2, and a straight line connecting intersecting points of the arc sections disposed on both sides across a stator recess section with the stator recess section is defined as L3, the stator recess section is configured to satisfy a relationship of "L2 < L1 < L3."

Description

Permanent magnet type rotating electric machine and compressor using the same

The present invention relates to a permanent magnet type rotating electric machine having a permanent magnet for a field in a rotor, and particularly suitable for use in a compressor in an air conditioner, a refrigerator, a freezer or a food showcase. The present invention relates to a rotary electric machine and a compressor using the same.

Conventionally, in this type of permanent magnet type rotating electric machine, concentrated winding is used for the stator winding that is the armature winding, and rare earth neodymium permanent magnet is used for the field magnet, which is small and highly efficient. It is planned. However, with the increase in output density due to the miniaturization and high efficiency, the influence of the non-linear magnetic characteristics (hysteresis) of the iron core becomes remarkable, and the spatial harmonic magnetic flux increases with the use of concentrated winding.

On the other hand, in the prior art described in Japanese Utility Model Laid-Open No. 3-106869 (Patent Document 1), the shape of the tip end portion of the stator (opposite surface to the rotor core) of the stator core is used, and the center portion is the rotor. It is described that it is formed concentrically with the outer peripheral surface of the iron core, and both end portions in the circumferential direction are formed in a straight line (flat surface) so as to be away from the outer peripheral surface of the rotor core. Thereby, the harmonic magnetic flux in a gap surface is reduced.

Japanese Utility Model Publication No. 3-106869

The efficiency of the permanent magnet type rotating electrical machine has been dramatically improved by using concentrated windings for the stator windings and high magnetic flux density permanent magnets for the field. On the other hand, in the case where the stator winding is a concentrated winding instead of the distributed winding, the harmonic flux increases in principle, and the harmonic flux is promoted by a permanent magnet with high magnetic flux density. It becomes. In other words, the non-linear magnetic characteristics of the iron core increase with the increase in output density due to the miniaturization and high efficiency, and the magnetic force of the permanent magnet with high magnetic flux density increases, so the vibration and noise of the permanent magnet type rotating electrical machine itself also increase. In particular, there is a problem that a frequency band in the middle range, which is most disturbing when incorporated in a compressor, becomes obvious.

In the thing of the said patent document 1, the shape of the teeth front-end | tip part in a stator iron core is made into a concentric circle with a center part and a rotor iron core, and the circumferential direction both ends are made straight, and it keeps away from a rotor core outer peripheral surface, gap The harmonic magnetic flux in the surface is reduced. As a result, the induced electromotive force waveform can be made into a sine wave to make the armature current into a sine wave, and the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current is reduced. As a result, the pulsating torque and radial electromagnetic excitation force generated in the permanent magnet type rotating electrical machine can be reduced, so that vibration and noise can be reduced.

However, in the above-mentioned Patent Document 1, although noise generated in a relatively low frequency band and a relatively high frequency band can be reduced, the noise in the middle frequency band that is most disturbing can be reduced. Has not been reduced sufficiently.

The reason for this is that, in the case of Patent Document 1, as the both end portions of the tip end portion of the teeth are moved away from the outer peripheral surface of the rotor core, the slot cross-sectional area of the stator decreases and the armature windings inserted into the slots decrease. This is because there is a limit to reducing the harmonic component of the magnetic flux in the electric motor without reducing the performance such as the efficiency of the permanent magnet type rotating electric machine.

In order to reduce the noise of the compressor, it is necessary to reduce the vibration generated from the motor itself or to prevent the vibration of the motor from being transmitted to the compressor frame (for example, a sealed container). In order to reduce the vibration of the electric motor, as described above, the harmonic component of the magnetic flux generated in the permanent magnet type rotating electric machine (electric motor) is reduced to reduce the pulsating torque and the radial electromagnetic excitation force. Etc. are effective.

On the other hand, in order to prevent the vibration of the motor from being transmitted to the compressor frame, a motor structure and a fixing method having a function to attenuate the vibration of the motor are effective.

Therefore, in order to reduce the compressor efficiency and noise, the harmonic component of the magnetic flux generated in the motor is sufficiently reduced to reduce the pulsation torque and the radial electromagnetic excitation force, and the compressor frame. It is important to make the structure in which the vibration of the motor is difficult to be transmitted.

An object of the present invention is to obtain a small, high-efficiency, low-noise permanent magnet type rotating electrical machine and a compressor using the same.

To achieve the above object, the present invention provides an annular core back, a plurality of teeth protruding radially inward from the core back and arranged in the circumferential direction, and a plurality of teeth formed between the teeth. A stator core having a slot; an armature winding disposed in the slot and wound around the teeth; a stator fixed to a frame; a rotor core; and the rotor core In a permanent magnet type rotating electrical machine having a permanent magnet embedded in a plurality of circumferential directions and having a stator and a rotor rotatably arranged through a gap, the stator is An arc portion formed on an outer peripheral side of the slot in the core back and fixed to the frame; and a stator concave portion formed on an outer peripheral side of the teeth in the core back, the stator concave portion Part A first straight line portion connected to one side and parallel to the width direction of the teeth, and the arc portion connected to an arc portion provided on the other side across the teeth and a second straight portion parallel to the width direction of the teeth. A straight portion, a third straight portion provided between the first and second straight portions and radially inward and parallel to the width direction of the teeth, one end of the third straight portion, and the first A fourth straight portion connecting the straight portions, a fifth straight portion connecting the other end of the third straight portion and the second straight portion, and a substantially trapezoidal shape. The distance between both ends inside the slot of the tooth tip of the tooth is L1, the width of the tooth is L2, and the straight line connecting the points where the circular arc portion and the stator concave portion provided on both sides across the stator concave portion intersect each other When the distance is L3,
L2 <L1 <L3
It is characterized by being configured so that

Another feature of the present invention is a compressor comprising: a compression mechanism that reduces the volume of a gas that is a working fluid; and a permanent magnet type rotary electric machine that drives the compression mechanism part. A compressor equipped with the above-described permanent magnet type rotating electrical machine.

According to the present invention, there is an effect that a small, high-efficiency, low-noise permanent magnet type rotating electrical machine and a compressor using the same can be obtained.

It is sectional drawing which shows Example 1 of the permanent-magnet-type rotary electric machine of this invention. It is sectional drawing which shows the shape of the rotor of the permanent magnet type rotary electric machine shown in FIG. It is principal part sectional drawing which shows the stator core shape of the stator of the permanent magnet type rotary electric machine shown in FIG. It is sectional drawing which shows the reference example of a permanent magnet type rotary electric machine. It is a figure which shows Example 2 of this invention, and is a longitudinal cross-sectional view of the compressor using the permanent magnet type rotary electric machine. It is a figure which shows Example 3 of this invention, and is sectional drawing which shows the shape of the rotor of a permanent magnet type rotary electric machine, and is a figure equivalent to FIG.

Hereinafter, specific examples of the permanent magnet type rotating electric machine and the compressor using the same according to the present invention will be described with reference to the drawings. In each figure, the part which attached | subjected the same code | symbol has shown the part which is the same or it corresponds.

Example 1 of the permanent magnet type rotating electrical machine of the present invention will be described with reference to FIGS. 1 is a sectional view showing a first embodiment of a permanent magnet type rotating electrical machine according to the present invention, FIG. 2 is a sectional view showing a shape of a rotor of the permanent magnet type rotating electrical machine shown in FIG. 1, and FIG. 3 is a permanent view shown in FIG. FIG. 4 is a cross-sectional view showing a main part of a stator core of a stator of a magnet-type rotating electrical machine, and FIG.

In the description of the first embodiment, a case will be described in which the present invention is applied to a permanent magnet type rotating electrical machine constituted by a 6-pole rotor and a 9-slot stator (6-pole 9-slot). The ratio of the number of rotor poles to the number of slots in the stator is 2: 3, but the ratio between the number of other poles and the number of slots and the number of poles of the other rotor and the number of slots in the stator is used. The present invention can be similarly applied to a thing, and almost the same effect can be obtained. For example, the number of poles of the rotor may be 4 poles or 8 poles. Note that the permanent magnet type rotating electric machine shown in FIG. 4 includes a 4-pole rotor and a 6-slot stator. Further, the permanent magnet type rotating electrical machine in the present embodiment is a so-called embedded magnet type rotating electrical 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.
The sectional view of the permanent magnet type rotating electrical machine of this embodiment shown in FIG. 1 shows a section in a direction perpendicular to the rotation axis (the same applies to FIGS. 2 to 4 and 6 described later). The first embodiment operates as a permanent magnet type synchronous motor.

As shown in FIG. 1, a permanent magnet type rotating electrical machine 1 is arranged to rotate with a stator 2 and a predetermined gap (gap) inside the stator 2 and rotating with a shaft (not shown). It is composed of a child 3.
The stator 2 includes a stator core 6 including an annular core back 5 and nine teeth 4 that protrude radially inward from the core back 5 and are arranged at substantially equal intervals along the circumferential direction. , And a concentrated winding armature winding 8 or the like wound so as to surround the teeth 4 in a slot 7 between the teeth 4 adjacent to each other in the circumferential direction. It is fixed to the closed container of the machine by shrink fitting or press fitting.

That is, the armature winding 8 is wound around the axial center of the tooth 4 radially arranged in the radial direction, and in the circumferential direction, a U-phase winding 8a, a V-phase winding 8b, W-phase windings 8c are arranged with a gap therebetween.
The stator 2 is configured by laminating the stator cores 6 (magnetic steel plates) in the axial direction, and nine slots (9 slots) are formed between the adjacent teeth 4. Yes.

The rotor 3 is composed of a rotor core 12 and six permanent magnets 14 embedded in the outer peripheral portion of the rotor core 12 and arranged at substantially equal intervals in the circumferential direction. Is a 6-pole rotor. A shaft hole 15 is formed in the center of rotation of the rotor 3, and a cylindrical shaft (not shown) is integrally fixed to the shaft hole 15, and the rotor 3 is an inner part of the stator 2. It is rotatably arranged on the peripheral surface side via a gap.

In the permanent magnet type rotating electrical machine 1 of the present embodiment, the rotor 3 has 6 poles and the stator 2 has 9 slots (6 poles 9 slots). The angle is 120 degrees (mechanical angle is 40 degrees).

In the permanent magnet type rotating electrical machine 1 of the present embodiment, when a three-phase alternating current is passed through the armature winding 8 composed of the three-phase windings 8a to 8c, a rotating magnetic field is generated. Due to this rotating magnetic field, the rotor 3 is rotated by electromagnetic force acting on the permanent magnet 14 and the rotor core 12 embedded in the rotor 3.

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 operates, the stator core 6 and the rotor core 12 are: It is preferable to form a laminated body in which a plurality of thin plates made of magnetic steel plates such as silicon steel plates are stacked.

FIG. 2 is a sectional view of the rotor of the permanent magnet type rotating electric machine according to the first embodiment of the present invention.
In FIG. 2, the rotor 3 has the rotor core 12 in which a shaft hole 15 is formed at the center of rotation. In the vicinity of the outer peripheral surface in the rotor core 12, a plurality of rectangular permanent magnet insertion holes 13 having an elongated cross section (six poles in the first embodiment) are formed. Each of the plurality of permanent magnet insertion holes 13 is inserted with a flat, single-letter permanent magnet 14 made of a magnet material, for example, rare earth neodymium.

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 is the d axis (flux axis). The axis (electric axis between permanent magnets) that is electrically orthogonal to the d-axis, that is, the electrical angle, is defined as the q-axis.

As shown in FIG. 2, in this embodiment, the rotor 3 is provided with one permanent magnet 14 per magnetic pole. The cross-sectional shape of the permanent magnet 14 is an elongated rectangular shape similar to the permanent magnet insertion hole 13, and the longitudinal direction of the permanent magnet 14 extends in a direction perpendicular to the d axis.

The rotor core 12 of the rotor 3 is provided with a rotor recess 11 that is recessed inward on the q axis between the poles of adjacent permanent magnets 14. The rotor recess 11 suppresses the q-axis magnetic flux as will be described later.

The rotor 3, that is, the rotor core 12, is located on the outer peripheral side of the rotor recess 11, and has an arcuate outermost periphery in which the gap length (gap) between the stator 2 and the teeth 4 is the shortest g 1. Part, that is, an arcuate part 12 a constituting a magnetic pole surface in the rotor core 12.

In the present embodiment, the magnetic pole surface of the rotor core 12 has a cut portion 12b connected to the end of the arcuate portion 12a, and the arcuate portion 12a passes through the cut portion 12b and the rotor concave portion. 11 is connected. A gap length g2 between the cut portion 12b and the teeth 4 of the stator 2 is configured to be wider than a gap length g1 between the arc-shaped portion 12a and the teeth 4 of the stator 2. In the present embodiment, the cut portion 12b is formed in a straight line shape, but is not necessarily limited to a straight line shape, and may be a curved surface shape.

In the present embodiment, the angle θp3 of the arc-shaped portion 12a around the rotation center O of the rotor 3, that is, the angle θp3 at which two straight lines connecting both ends of the arc-shaped portion 12a and the rotation center O intersect is The angle is 90 ° to 120 °.

The rotor concave portion 11 smoothly smoothes two

linear portions

11b and 11c formed substantially parallel to the radial thickness direction of the permanent magnet 14 and the rotor inner peripheral side end portions of the two

linear portions

11b and 11c. The curved portion 11a is connected between the ends facing the q-axis on the inner peripheral side magnetic pole surface of two adjacent permanent magnets located on both sides of the q-axis, that is, the latest It is located on the rotor inner peripheral side from the virtual straight line 9 connecting the contact portions. In the present embodiment, the starting position of the curved portion 11a is substantially located at the portion of the virtual straight line 9, but may be located at the rotor inner peripheral side of the virtual straight line 9. In addition, as long as at least a part of the curved portion 11a is configured to be located on the inner peripheral side of the virtual straight line 9, the start position of the curved portion 11a may be configured to be positioned on the outer peripheral side of the virtual straight line 9. good.

As described above, in the present embodiment, the bottom of the rotor recess 11 in the radial direction is configured to be deeper than the inner peripheral side magnetic pole surface of the permanent magnet 14. Thus, by providing the curved part 11a in the rotor recessed part 11, the influence of the stress accompanying a rotor centrifugal force can be relieved in a high speed region. That is, since the concentration of stress associated with the rotor centrifugal force in the rotor recess 11 is alleviated, the strength of the rotor 3 against the centrifugal force is improved.

Further, in the direction perpendicular to the q-axis, the interval between the two

straight portions

11b and 11c is configured to increase from the rotor inner peripheral side toward the rotor outer peripheral side. Furthermore, the cross-sectional area of the rotor recess 11 is configured to be larger than the cross-sectional area of the cut portion 12b.

Further, around the rotation center O of the rotor 3, the angle between the end portions of the outer 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 of the rotor recess 11 When the angle between the end portions of the outer peripheral side of the

rotors

11b and 11c is θp2, in this embodiment, the angles θp1 and θp2 are
0.18 ≦ θp2 / θp1 ≦ 0.5
It is set to satisfy the relationship.

In this embodiment, as described above, the pitch of the slots 7 in the stator 2 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 angles are “120 ° ≦ θp1 <180 °” and “0 ° <θp2 ≦ 60 °”. Therefore, “0 <θp2 / θp1 ≦ 0.5 (= 60 ° / 120 °)”.

Further, according to the study of the present inventor, in the case of the rotor 3 provided with the rotor recess 11 having the curved portion 11a as in the present embodiment, by setting “0.18 ≦ θp2 / θp1”, It was found that the q-axis magnetic flux was suppressed to suppress the armature reaction, and the torque improvement effect in the high speed range was obtained.

Further, in the present embodiment, the rotor 3 has an outer peripheral side of the permanent magnet insertion hole 13 (or the permanent magnet 14) (the arc-shaped portion 12a in the rotor core 12 and the outer peripheral side magnetic pole surface of the permanent magnet 14). The plurality of slits 10a to 10d are provided symmetrically so as to sandwich the d-axis on both the left and right sides separated by a predetermined distance from the d-axis. Further, no slit is provided on the d-axis and in the vicinity of the d-axis so that the magnetic flux easily passes through the vicinity of the d-axis.

Here, the

slits

10a and 10b are arranged symmetrically with respect to the d-axis, and the

slits

10c and 10d are arranged symmetrically with respect to the d-axis between the

slits

10a and 10b. In the present embodiment, among the slits 10a to 10d, the distance between the

slits

10c and 10d arranged closest to the d-axis is set to the minimum width of the tooth 4 in general.

Specifically, in the present embodiment, among the slits 10a to 10d, the slit 10c closest to the d-axis in the direction along the magnetic pole plane of the plate-like permanent magnet 14, that is, the direction geometrically perpendicular to the d-axis. And the distance between the end portions of 10d is set to the minimum width of the teeth 4 in general.

Further, the slits 10 a to 10 d are arranged so as to be inclined so that the magnetic flux of the permanent magnet 14 is collected on the teeth 4. That is, the direction in which the slits 10a to 10d go to the outer peripheral side is inclined inward from a direction parallel to the d-axis so as to make an acute angle with the d-axis. Since the induced electromotive force waveform can be made sine wave by such slits 10a to 10d, the armature current can be made sine wave accordingly, and the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current is reduced. can do. That is, the slits 10a to 10d suppress the armature reaction and reduce the harmonic component of the magnetic flux in the rotating electric machine.

Incidentally, in the permanent magnet type rotating electrical machine 1 for a compressor targeted by this embodiment, vibration and noise often become a problem. In particular, the concentrated winding armature winding 8 is a winding arranged at an electrical angle of 120 degrees, so that harmonic components such as the fifth and seventh orders of the in-machine magnetic flux are large, causing vibration and noise. The pulsating torque and the radial electromagnetic excitation force are also increased.

Here, FIG. 4 shows a reference example similar to Patent Document 1 described above. In the reference example shown in FIG. 4, the tip portion (tooth tip portion) 16 of the teeth 4 in the stator 2 has a central portion concentric with the rotor core 12, and both ends of the teeth tip portion 16 are linear. That is, it is kept away from the rotor core 12.

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, so that the harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current can be reduced. Torque and radial electromagnetic excitation force can be reduced.

However, since the cross-sectional area of the slot 7 decreases as the both end sides of the tooth tip 16 are moved away from the rotor 3, the diameter of the wire of the armature winding 8 provided in the slot 7 is reduced, or There arises a problem that the number of turns (number of turns) of the child winding 8 has to be reduced. Therefore, in order to prevent a reduction in efficiency, both ends of the tooth tip 16 cannot be sufficiently separated from the rotor core 12, and there is a problem that vibration and noise cannot be reduced sufficiently.

In order to solve the above problems, in the first embodiment, the shape of the stator 2 is configured as shown in FIG. That is, in this embodiment, as shown in FIG. 3, a stator concave portion 17 is provided on the outer peripheral side of the teeth 4 of the stator core 6. The stator 2 is fixed to a compressor frame (sealed container) or the like by shrink fitting or press fitting (see FIG. 5 to be described later). In this case, the contact portion between the frame and the stator 2 is fixed. An arc portion 5a on the outer periphery of the core back 5 of the core 6 is formed, and the stator 2 is fixed to the frame by the arc portion 5a.

More specifically, on the outer periphery of the core back 5 of the stator core 6, the arc portion 5 a fixed to the frame and the stator recess 17 formed on the outer peripheral side of the teeth 4 are provided. Yes.

The stator recess 17 includes three straight portions (17a, 17b, 17c) along (parallel to) the width direction of the teeth 4 and two straight portions (17d) respectively connecting the end portions of the three straight portions. , 17e). That is, the stator concave portion 17 is connected to one of the circular arc portions 5a and parallel to the width direction of the teeth 4, and the circular arc portion is provided on the other side across the teeth. A second linear portion 17b connected to the circular arc portion and parallel to the width direction of the teeth, and a second linear portion 17b provided between the first and second linear portions and radially inward and parallel to the width direction of the teeth. 3 linear portions 17c, one end of the third linear portion 17c, the fourth linear portion 17d connecting the first linear portion 17a, the other end of the third linear portion 17c, and the second It has a fifth trapezoidal shape having a fifth straight portion 17e connecting the straight portion 17b.

Further, the stator recess 17 is not in contact with the frame. By adopting such a configuration, it is possible to suppress pulsation torque and radial electromagnetic excitation force in the rotating electrical machine from being transmitted to the compressor frame.

Further, the distance between the left and right ends of the tooth tip 16 inside the slot 7 is L1, the width of the tooth 4 is L2, and the arc portion 5a and the stator recess 17 provided on both sides of the stator recess 17 are provided. A straight line distance connecting the intersecting points (a distance of a portion not in contact with the frame on the back side of the teeth 4) is defined as L3. The distance L3 will be described in more detail. One of the arc portions 5a provided on both sides of the stator recess 17 on the outer periphery of the stator core 5 and the first straight portion 17a of the stator recess 17 It is the distance between the intersecting point and the point where the other of the arc portions 5a and the second straight line portion 17b intersect. Thus, when the L1, L2, and L3 are defined as described above,
L2 <L1 <L3
It is configured to satisfy the relationship.
Further, the depth L4 of the stator recess 17 is configured to be shorter than the length of the teeth 4 and the thickness of the core back 5 so that the flow of effective magnetic flux in the rotating electrical machine is not impaired as much as possible.

As described above, the first embodiment is a permanent magnet type rotating electric machine that combines the structure of the rotor 3 described in FIG. 2 and the structure of the stator 2 described in FIG. Since the harmonic component of the magnetic flux in the rotating electrical machine due to the influence can be sufficiently reduced, the generation of the pulsating torque and the radial electromagnetic excitation force can be suppressed to achieve a small size, high efficiency, and low noise. Further, it is possible to suppress pulsation torque and radial electromagnetic excitation force generated in the rotating electrical machine from being transmitted to the frame.

As a result, a small, high-efficiency, low-noise and excellent permanent magnet type rotating electrical machine can be obtained. If this permanent magnet type rotating electrical machine 1 is used in a compressor constituting a refrigeration cycle, it is small and highly efficient. A low noise compressor can be obtained.

That is, according to the present embodiment, since the harmonic component of the magnetic flux can be reduced without reducing the slot cross-sectional area of the stator, a small-sized, high-efficiency, low-noise permanent magnet type rotating electrical machine and The effect which can obtain the used compressor is acquired.

A second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view of a compressor using a permanent magnet type rotating electrical machine, showing the second embodiment.
A compressor 20 shown in FIG. 5 includes a compression mechanism unit 21 that reduces the volume of a gas that is a working fluid such as a refrigerant, and an electric motor unit 22 that drives the compression mechanism unit 21, and the electric motor unit 22 is the above-described one. The permanent magnet type rotating electrical machine 1 of the first embodiment is mounted. The compressor 20 in the second embodiment is used in a refrigeration cycle apparatus such as an air conditioner, and the compression mechanism portion 21 and the electric motor portion 22 are accommodated in a cylindrical sealed container (frame) 23. ing. Further, R32 refrigerant is sealed as a working fluid in the sealed container 23.

The configuration of the compressor 20 shown in FIG. 5 will be described in detail.
In the sealed container 23, the compression mechanism part 21 and the electric motor part 22 are accommodated.
In the present embodiment, the compression mechanism portion 21 is constituted by a scroll compression mechanism including a fixed scroll 24 and a turning scroll 25, and the fixed scroll 24 is attached to a frame 26 fixed to the inner surface of the hermetic container 23 with a bolt or the like. Fastened by fastening means.

The fixed scroll 24 includes an end plate 24a, a spiral fixed scroll wrap 24b formed so as to stand upright on the end plate 24a, a discharge port 24c formed in a substantially central portion of the end plate 24a, and the like. ing. The orbiting scroll 25 includes an end plate 25a, a spiral orbiting scroll wrap 25b formed so as to stand upright on the end plate 25a, a boss portion 25c formed at the center of the back surface of the end plate 25a, and the like. Yes.

The orbiting scroll 25 is meshed with the fixed scroll 24 and the electric motor unit (permanent magnet type rotating electrical machine) 22 rotates, whereby the orbiting scroll 25 is orbitally moved via the crankshaft 27 to perform a compression operation. .

That is, the crankshaft 27 is inserted into a shaft hole 15 (see FIGS. 1 and 2) formed in the rotor 3 of the electric motor unit 22 and is configured integrally with the rotor 3. The crankshaft A crank portion (eccentric pin portion) 27a is formed at the upper end portion of 27. The crank portion 27 a of the crankshaft 27 is inserted into and engaged with the boss portion 25 c of the orbiting scroll 25. The crankshaft 27 is rotatably supported by a slide bearing (main bearing) 28 provided on the frame 26 and a ball bearing 30 provided on a lower frame 29 in the lower part of the sealed container 23.

Therefore, when the electric motor unit 22 is driven and the rotor 3 rotates, the crankshaft 27 also rotates, causing the orbiting scroll 25 to perform an orbiting motion via the crank portion 27a. When the orbiting scroll 25 starts the orbiting motion, the refrigerant gas of the refrigeration cycle is sucked into the suction chamber formed on the outer peripheral side of the fixed scroll 24 from the suction pipe 31 and is formed by the fixed scroll 24 and the orbiting scroll 25 from here. After being confined in the compression chamber 32, it is compressed along with the orbiting motion of the orbiting scroll 25, moves to the center side, and is discharged from the discharge port 24 c to the discharge chamber above the sealed container 23.

That is, the compression chamber located on the outermost diameter side among the compression chambers 32 formed by the fixed scroll 24 and the orbiting scroll 25 moves toward the centers of the

scroll members

24 and 25 along with the orbiting motion, The volume gradually decreases. When the compression chamber 32 reaches the vicinity of the center of the

scroll members

24 and 25, the compression chamber 32 communicates with the discharge port 24c, and the compressed gas is discharged from the compression chamber 32 to the discharge chamber through the discharge port 24c.

The discharged compressed refrigerant gas flows from the discharge chamber through the gas passage 33 provided on the outer peripheral side of the fixed scroll 24 and the frame 26 to the electric motor chamber side below the frame 26 and in the refrigerant gas. After the oil is separated, the oil is supplied to the refrigeration cycle from a discharge pipe 34 provided on the side wall of the sealed container 23. The separated oil is stored in an oil reservoir 35 formed in the lower part of the sealed container 23. The oil stored in the oil reservoir 35 passes through an oil hole 36 formed in the crankshaft 27 in the axial direction, and the centrifugal force due to the rotation of the crankshaft 27 and the difference between the discharge pressure and the low pressure side. The sliding bearing 28, the ball bearing 30, and the sliding portion of the compression mechanism 21 are supplied by pressure.

Incidentally, 8 is an armature winding of the

stator

2, 37 is a balance weight, and 38 is a power supply terminal. The electric motor unit 22 composed of the permanent magnet type rotating electrical machine 1 is controlled by a separate inverter (not shown) and is rotated at a rotation speed suitable for the compression operation.

The effect of the compressor of the second embodiment equipped with the permanent magnet type rotating electric machine of the first embodiment will be described with reference to Table 1. Table 1 shows a conventional general permanent magnet having various rotor shapes and stator shapes only in the permanent magnet type rotating electric machine, with the same basic configuration as the compressor 20 of the second embodiment described above. It is the measurement result which conducted the auditory test of the noise by the compressor incorporating the rotary electric machine and the compressor carrying the rotary electric machine of the reference example shown in FIG.

In Table 1, the frequency bands of annoying noises are roughly divided into three ranges: low, middle and high. The low frequency range is less than 1 kHz, the middle frequency range is 1 kHz or more and less than 4 kHz, and the high frequency range is 4 kHz or more and 10 kHz or less.

According to the experiment, it was found that the noise component in the middle range, which is particularly problematic in hearing, appears more prominently in a compressor equipped with a conventional general permanent magnet type rotating electrical machine (hereinafter also referred to as a conventional compressor). . Further, the compressor (hereinafter also referred to as the compressor of the reference example) equipped with the rotating electrical machine of the reference example shown in FIG. 4 has a reduction effect on the low-frequency and high-frequency noise components as compared with the conventional compressor. However, although there was a slight change in the audibility with respect to the mid-range noise component, it was not sufficiently reduced.

On the other hand, in the case of the compressor of the second embodiment in which the rotating electric machine of the first embodiment described above is mounted, that is, the compressor in which the rotating electric machine combining the rotor shape shown in FIG. 2 and the stator shape shown in FIG. As compared with the compressor of the reference example, in addition to having the same noise reduction effect, it was confirmed that the noise component in the middle region can be greatly reduced.

As a result of analysis of noise generation factors, in the compressor of the reference example, as the harmonic component of the magnetic flux in the rotating electrical machine, the lower order harmonic components such as the fifth order and the seventh order, and the relatively higher order such as the 25th order and 27th order components. It has been observed that the harmonic components of are greatly reduced. However, it has been found that the relatively middle harmonic components such as the 11th and 13th components and the 15th and 17th components are not reduced as the harmonic components of the magnetic flux in the rotating electrical machine.

On the other hand, in the case of the compressor according to the second embodiment in which the rotating electric machine according to the first embodiment is mounted, the lower-order and higher-order harmonic components of the magnetic flux in the rotating electric machine can be reduced and compared with the compressor according to the reference example. It was also found that the harmonic components in the target midrange could be significantly reduced compared to the compressor of the reference example. This is because, in the case of the compressor of the second embodiment, the harmonic component of the magnetic flux in the rotating electrical machine can be sufficiently reduced, and the pulsating torque and the radial electromagnetic excitation force in the rotating electrical machine are reduced by the compressor 20. This is because it is possible to suppress the transmission to the hermetic container (frame) 23.

As shown in Table 1, in the compressor of the reference example, the overall noise value was 67.4 dB, whereas in the compressor of the second embodiment, the noise value was reduced to 64.3 dB. Has been. As described above, according to the compressor of the second embodiment, it is possible to greatly reduce the noise component in the middle range, which is a problem particularly in hearing, and to reduce the overall noise value.

In the second embodiment, as described above, since the permanent magnet type rotating electrical machine 1 of the first embodiment described above is used for the compression chamber 20, a compact, high-efficiency, low-noise compressor 20 can be obtained. it can. That is, since the permanent magnet type rotating electric machine 1 has the rotor 3 having the structure described with reference to FIG. 2, the torque of the permanent magnet type rotating electric machine 1 can be made larger than that of the conventional one, particularly in the high speed range. Moreover, since the power factor fall by the influence of an armature reaction can also be suppressed, the torque fall in a high speed region is suppressed. For this reason, it becomes possible to achieve high efficiency and downsizing of the permanent magnet type rotating electrical machine.

¡By using a compressor equipped with such a small and highly efficient permanent magnet type rotating electrical machine, the efficiency of the compressor can be improved and energy can be saved. In addition, the operating range can be expanded, such as enabling high-speed operation of the compressor.

In many of the current air conditioners, the R410A refrigerant is sealed in the sealed container 23, and the ambient temperature of the permanent magnet type rotating electric machine is often 80 ° C. or higher. In the present embodiment, since the R32 refrigerant having a smaller global warming potential is employed, the ambient temperature further increases. The permanent magnet 14, particularly a neodymium magnet, has a residual magnetic flux density that decreases at a high temperature, and an armature current increases to ensure the same output, but the high-efficiency permanent magnet type rotating electrical machine 1 of the first embodiment is mounted. A reduction in efficiency can be suppressed by using the compressor.

In the second embodiment, R32 is adopted as the refrigerant. However, refrigerants such as R32 and He have a larger leakage from the gap in the compressor than refrigerants such as R22, R407C, and R410A, and are particularly slow. During operation, the ratio of leakage to the amount of circulation increases, which reduces efficiency. In order to improve the efficiency at the time of low circulation (low speed operation), if the compression mechanism is downsized and the rotational speed is increased to obtain the same circulation, leakage loss can be reduced. Furthermore, it is preferable to increase the maximum rotational speed in order to ensure the maximum circulation amount.

On the other hand, by using the compressor equipped with the permanent magnet type rotating electrical machine 1 of the first embodiment, it is possible to increase the maximum torque and the maximum rotation speed, and it is possible to reduce the loss in a high speed region. As described above, the compressor according to the second embodiment is particularly effective when a refrigerant that easily leaks, such as R32 or He, is used as the refrigerant, and the efficiency can be improved.

In addition, according to the present embodiment, as shown in FIG. 3, since the stator concave portion 17 having a large area is provided on the outer periphery of the stator 2 in the permanent magnet type rotating electrical machine 1, an airtight container (frame) 23 is provided. Lubricating oil that has reached the upper surface of the stator 2 along the inner peripheral surface easily passes through the stator recess 17. As a result, it is possible to reduce the oil rise that the amount of lubricating oil in the compressor is insufficient during high-speed operation.

In the second embodiment, R32 is used as a refrigerant, but the present invention is not limited to the type of refrigerant. In the example shown in FIG. 5, the compressor is a scroll compressor. However, the present invention can be similarly applied to a compressor having another compression mechanism such as a rotary compressor. is there.

A third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram illustrating the third embodiment, which is a cross-sectional view illustrating the shape of the rotor of the permanent magnet type rotating electrical machine, and corresponds to FIG. 2 described above.
In FIG. 6, the same parts as those in FIG. 2 are denoted by the same reference numerals, description thereof is omitted, and different parts are described.

The third embodiment is different from the rotor 3 shown in FIG. 2 of the first embodiment, and includes two permanent magnets 14A per magnetic pole of the rotor 3A. In the cross section shown in FIG. 6, the two permanent magnets 14 </ b> A are arranged in a convex V shape with respect to the shaft hole 15. That is, the cross sections of the two permanent magnets 14A have the same shape as that of the first embodiment, but are arranged in a convex V shape toward the rotation center O of the rotor 3 with the d axis as the axis of symmetry. As a result, high torque is achieved.

Further, the other configuration of the rotor 3A in the third embodiment is the same as that of the rotor 3 of the first embodiment. In other words, the rotor recess 11 is provided, and the values of the angles θp1, θp2, θp3, etc. in the rotor 3A are similarly configured.

By using a permanent magnet type rotating electric machine in combination with the rotor 3A of the third embodiment and the stator 2 having the structure described in FIG. 3 of the first embodiment, the harmonics of the magnetic flux in the rotating electric machine due to the influence of the armature reaction. Since the components can be sufficiently reduced, the generation of pulsation torque and radial electromagnetic excitation force can be suppressed to achieve a small size, high efficiency, and low noise. Further, it is possible to suppress pulsation torque and radial electromagnetic excitation force generated in the rotating electrical machine from being transmitted to the frame.
Furthermore, also in the third embodiment, as in the first embodiment, it is possible to suppress the torque reduction in the high speed range, and from this point, it becomes possible to increase the efficiency and miniaturization of the permanent magnet type rotating electric machine. 1 can be obtained.

In addition, this invention is not limited to the Example mentioned above, Various modifications are included. 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.

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet type rotary electric machine (drive motor), 2 ... Stator, 3, 3A ... Rotor, 4 ... Teeth, 5 ... Core back, 5a ... Arc part, 5b ... Stator recessed part, 6 ... Stator core 7 ... slot, 8 armature winding, 8a ... U phase winding, 8b ... V phase winding, 8c ... W phase winding, 9 ... virtual straight line, 10a, 10b, 10c, 10d ... slit, 11 ... rotation Child concave part, 11a ... curve part, 11b, 11c ... linear part, 12 ... rotor core, 12a ... arc-shaped part, 12b ... cut part, 13,13A ... permanent magnet insertion hole, 14,14A ... permanent magnet, 15 ... Shaft hole, 16 ... teeth tip, 17 ... stator recess, 17a ... first straight part, 17b ... second straight part, 17c ... third straight part, 17d ... fourth straight part, 17e ... first 5 linear portions, 20... Compressor, 21... Compression mechanism portion, 22. ... Sealed container, 24 ... Fixed scroll, 24a ... End plate, 24b ... Fixed scroll wrap, 24c ... Discharge port, 25 ... Revolving scroll, 25a ... End plate, 25b ... Revolving scroll wrap, 25c ... Boss part, 26 ... Frame, 27 ... Crankshaft, 27a ... Crank part, 28 ... Sliding bearing (main bearing), 29 ... Lower frame, 30 ... Ball bearing, 31 ... Suction pipe, 32 ... Compression chamber, 33 ... Gas passage, 34 ... Discharge pipe, 35 ... oil retaining part, 36 ... oil hole, 37 ... balance weight, 38 ... power terminal.

Claims

An annular core back, a plurality of teeth projecting radially inward from the core back and arranged circumferentially, a stator core having a plurality of slots formed between the teeth, and the inside of the slots An armature winding disposed on the teeth and fixed to a frame;
A rotor iron core, and a plurality of permanent magnets embedded in the rotor iron core and arranged in the circumferential direction, and a rotor arranged rotatably through the stator and a gap;
In a permanent magnet type rotating electrical machine comprising:
The stator includes a circular arc portion formed on the outer peripheral side of the slot in the core back and fixed to the frame, and a stator concave portion formed on the outer peripheral side of the teeth in the core back,
The stator recess is connected to one of the arc portions and is connected to a first straight portion parallel to the width direction of the teeth, and the arc portion is connected to an arc portion provided on the other side across the teeth. A second linear portion parallel to the width direction of the teeth, a third linear portion provided between the first and second linear portions and radially inward and parallel to the width direction of the teeth, and A fourth straight line connecting one end of the third straight line and the first straight line; and a fifth straight line connecting the other end of the third straight line and the second straight line. Has a substantially trapezoidal shape,
The distance between both ends inside the slot of the tooth tip of the tooth is L1, the width of the tooth is L2, and the points where the circular arc portion provided on both sides of the stator recess and the stator recess intersect are connected When the straight line distance is L3,
L2 <L1 <L3
A permanent magnet type rotating electrical machine, characterized in that the relationship is
In the permanent magnet type rotating electrical machine according to claim 1,
When the magnetic flux axis of the permanent magnet is the d-axis and the axis orthogonal to the d-axis in terms of electrical angle is the q-axis,
The rotor core has a rotor recess that is recessed on the inner circumference side on the q-axis,
The rotor recess is composed of two straight portions along the thickness direction of the permanent magnet, and a curved portion connected to each end on the rotor inner peripheral side of the two straight portions,
When the angle θp1 between the ends of the magnetic pole surface on the outer periphery side of the permanent magnet is set around the rotation center O of the rotor, and the angle θp2 between the ends on the rotor outer periphery side of the two linear portions The relationship between the angle θp1 and the angle θp2 is
0.18 ≦ θp2 / θp1 ≦ 0.5
A permanent magnet type rotating electrical machine, characterized in that:
In the permanent magnet type rotating electrical machine according to claim 2,
The curved portion is positioned on the rotor inner peripheral side with respect to the virtual straight line connecting the ends facing the q axis of the inner peripheral magnetic pole surfaces of the two permanent magnets positioned on both sides of the q axis. A permanent magnet type rotating electrical machine.
In the permanent magnet type rotating electrical machine according to claim 2,
A permanent magnet type rotating electrical machine characterized in that, in a direction perpendicular to the q-axis, an interval between the two linear portions widens from the rotor inner peripheral side toward the rotor outer peripheral side.
In the permanent magnet type rotating electrical machine according to claim 2,
A permanent magnet type rotating electrical machine, wherein a magnetic pole surface of the rotor core has an arcuate portion.
In the permanent magnet type rotating electrical machine according to claim 5,
A permanent magnet type rotating electrical machine, wherein a plurality of slits are provided symmetrically with respect to the d-axis between the arcuate portion and the outer peripheral side magnetic pole surface of the permanent magnet.
In the permanent magnet type rotating electrical machine according to claim 5,
The magnetic pole surface of the rotor core has a cut portion connected to an end portion of the arc-shaped portion, the arc-shaped portion is connected to the rotor concave portion via the cut portion, and the cut portion and the The permanent magnet type rotating electrical machine, wherein a gap between the stator and the stator is wider than a gap between the arcuate portion and the stator.
In the permanent magnet type rotating electrical machine according to claim 7,
The cut portions are formed on both sides of the arcuate portion, and these cut portions are respectively arranged on the rotor outer peripheral side end of the closest straight portion of the two straight portions forming the rotor concave portion. A permanent magnet type rotating electrical machine characterized in that each is connected and formed in a straight line.
In the permanent magnet type rotating electrical machine according to claim 7,
A permanent magnet type rotating electrical machine, wherein a cross-sectional area of the rotor concave portion is larger than a cross-sectional area of the cut portion.
In the permanent magnet type rotating electrical machine according to claim 5,
Around the rotation center O of the rotor, the angle θp3 of the arcuate portion is an electrical angle of 90 ° or more and 120 ° or less.
In the permanent magnet type rotating electrical machine according to claim 2,
A permanent magnet rotating electrical machine characterized in that the ratio of the number of poles of the rotor to the number of slots of the stator is 2: 3.
In the permanent magnet type rotating electrical machine according to claim 2,
The permanent magnet embedded in the rotor iron core is composed of two permanent magnets per magnetic pole of the rotor, and the two permanent magnets have the d-axis as an axis of symmetry and the rotation center of the rotor. A permanent magnet type rotating electrical machine characterized by being arranged in a convex V shape toward O.
In a compressor comprising a compression mechanism that reduces the volume of a gas that is a working fluid, and a permanent magnet type rotating electrical machine that drives the compression mechanism,
A compressor, wherein the permanent magnet type rotating electrical machine is equipped with the permanent magnet type rotating electrical machine according to any one of claims 1 to 12.
The compressor according to claim 13,
An R32 refrigerant is sealed in the compressor.