TWI655828B - Permanent magnet rotary electric machine and compressor using same - Google Patents

Abstract

A small, high-efficiency, low-noise permanent magnet rotating electrical machine is obtained.

A permanent magnet type rotating electric machine includes: a stator core having a plurality of teeth and grooves; a stator wound with an armature; and a rotor having a rotor core and a plurality of permanent magnets embedded in the rotor core. The stator includes: a circular arc portion fixed to the frame; and a stator concave portion formed on the outer peripheral side; the stator concave portion having first and second straight portions connected to the circular arc portion and parallel to the width direction of the teeth, a third straight portion that is disposed on the inner side in the radial direction and that is parallel to the width direction of the tooth, and a fourth and fifth straight portion that connects the first and second straight portions of the third straight portion to form a substantially trapezoidal shape; The distance between the both ends of the inside of the groove at the end portion is (L1), the width of the tooth is (L2), and the line connecting the concave portion of the stator and the arc portion provided on both sides and the stator concave portion are connected to each other. When the distance is (L3), it constitutes a relationship of "L2 < L1 < L3".

Description

Permanent magnet rotary electric machine and compressor using same

The present invention relates to a permanent magnet type rotating electric machine in which a permanent magnet for field magnetism is provided to a rotor, and in particular, a permanent magnet type rotating electric machine used in a compressor in an air conditioner, a refrigerator, a freezer, or a food display cabinet. And the compressor that uses it.

Conventionally, in such a permanent magnet type rotating electric machine, a concentrated winding is used for the stator winding which is an armature winding, and a permanent magnet of a rare earth type is used for the field magnet, and the size and efficiency are pursued. However, as the output density due to small size and high efficiency increases, the influence of the non-orbital linear magnetic characteristics (hysteresis) of the core becomes remarkable, and the spatial harmonic magnetic flux increases in interaction with the concentrated winding.

In the prior art described in Japanese Laid-Open Patent Publication No. Hei-3-106869 (Patent Document 1), the center portion and the outer peripheral surface of the rotor core are formed concentrically, and both ends in the circumferential direction are formed. In the form of a straight line (flat surface), the shape of the end portion of the tooth (the opposing surface of the rotor core) in the stator core is made to be distant from the outer peripheral surface of the rotor core. Thereby, the high harmonic flux in the gap surface is reduced.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 3-106869

A concentrated winding is used in the stator winding, and a permanent magnet having a high magnetic flux density is used in the field magnet, whereby the efficiency of the permanent magnet rotating electric machine is drastically improved. But on the opposite side, in contrast to the stator winding is made into a distributed winding to make a concentrated winding, in principle, in addition to increasing the high harmonic flux, and a permanent magnet with a high magnetic flux density contributes to its high harmonic flux. result. In other words, there is a problem that the non-orbital linear magnetic property of the core increases as the output density increases due to small size and high efficiency, and further, the magnetic force of the permanent magnetic system of high magnetic flux density becomes large, forever. The vibration or noise of the magnetic rotating electrical machine itself is also likely to increase, and in particular, in the case of being loaded into the compressor, the frequency band of the most harsh intermediate midrange is remarkable.

In the above-described Patent Document 1, the shape of the end portion of the tooth in the stator core is concentric with the center of the rotor, and the both ends in the circumferential direction are linear, and are separated from the outer peripheral surface of the rotor core. The high harmonic flux in the gap surface is reduced. Accordingly, the sinusoidal induced electromotive force waveform can sine wave the armature current, and reduce the high-harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current. This result can reduce the pulsating torque or the radial electromagnetic exciting force generated in the permanent magnet rotating electrical machine. For the sake of this, vibration or noise can be reduced.

However, in Patent Document 1 described above, it is possible to reduce the noise of the frequency band of the comparative low range and the frequency band of the relatively high range, but the noise of the frequency band of the most harsh middle range cannot be sufficiently reduced.

This is because, in the case of Patent Document 1, when both end portions of the tooth end portion are separated from the outer peripheral surface of the rotor core, the groove sectional area of the stator is reduced, but the armature winding inserted into the groove is reduced, so The performance such as the efficiency of the permanent magnet rotating electrical machine is not lowered, but there is a limit to reducing the harmonic component of the magnetic flux in the motor.

Further, in order to reduce the noise of the compressor, it is necessary to reduce the vibration generated by the motor itself or to transmit the vibration of the motor to the frame of the compressor (for example, a closed container). In order to reduce the vibration of the motor, as described above, it is effective to reduce the high harmonic component of the magnetic flux generated in the permanent magnet type rotating electric machine (electric motor), and to reduce the pulsation torque or the radial direction electromagnetic exciting force.

On the other hand, in order to prevent the vibration of the motor from being transmitted to the frame of the compressor, it is effective to have a motor structure or a fixing method that attenuates the vibration of the motor.

Therefore, in order to reduce the high harmonic content of the magnetic flux generated in the motor, the pulsation torque and the radial electromagnetic excitation force are reduced, and the vibration of the motor is hardly transmitted to the compressor. The construction of the framework is important.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized, high-efficiency, low-noise permanent magnet type rotating electric machine and a compressor using the same.

In order to achieve the above object, the present invention is a permanent magnet type rotating electric machine comprising: a stator having a ring-shaped core back, a plurality of teeth projecting from the core back toward the inner side in the radial direction and arranged in the circumferential direction, and having a stator core formed with a plurality of grooves between the teeth, and an armature winding wound around the teeth disposed in the groove, and fixed to the frame; and a rotor having a rotor a core, and a plurality of permanent magnets embedded in the rotor core and disposed in the circumferential direction, and the stator is disposed to rotate freely via the gap; wherein the stator includes: the outer groove formed in the core back a peripheral side of the arc portion of the frame and a stator recess formed on an outer peripheral side of the teeth in the core back; the stator recess having: the first arc portion and the teeth a first straight portion parallel to the width direction, the tooth is wrapped with the arc portion, and is connected to the arc portion provided on the other side and parallel to the width direction of the tooth a straight portion, and a third straight portion that is located further in the radial direction than the first and second straight portions and that is parallel to the width direction of the teeth, and the first straight portion a third straight portion in which one end of the straight portion is connected to the first straight portion, and a fifth straight portion connected to the other end of the third straight portion and the second straight portion, and has a substantially trapezoidal shape; The distance between the both ends of the groove inner end of the tooth end portion is L1, the width of the tooth is L2, and the arc portion provided on both sides of the stator recess portion intersects the stator recess portion. When the straight line distances of the points are connected as L3, the composition is L2<L1<L3

Relationship.

According to still another aspect of the present invention, a compressor includes: a compression mechanism that compresses an operating fluid, that is, a volume of a gas, and a permanent magnet rotating electrical machine that drives the compression mechanism; and the permanent magnet rotating electrical machine The above-mentioned permanent magnet type rotating electric machine is mounted.

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

Hereinafter, a specific embodiment of the permanent magnet rotating electrical machine of the present invention and a compressor using the same will be described using the drawings. In the respective drawings, the same reference numerals are given to the same or equivalent parts.

[Example 1]

Embodiment 1 of the permanent magnet type rotating electric machine of the present invention will be described with reference to Figs. 1 is a cross-sectional view showing a first embodiment of a permanent magnet type rotating electric machine according to the present invention; FIG. 2 is a cross-sectional view showing a shape of a rotor of the permanent magnet type rotating electric machine shown in FIG. 1; A cross-sectional view of an important part of a stator core shape of a stator of a magnetic rotating electrical machine; and FIG. 4 is a cross-sectional view showing a reference example of a permanent magnet rotating electrical machine.

In the description of the first embodiment, the case where the present invention is applied to a permanent magnet type rotating electric machine including a six-pole rotor and a nine-slot stator (six-pole 9-slot) will be described. Further, the ratio of the number of poles of the rotor to the number of slots of the stator is 2:3. However, the ratio of the number of other poles or slots, the number of poles of other rotors, and the number of slots of the stator can be similarly applied, and can be approximated. The same effect. For example, the number of poles of the rotor may be 4 poles or 8 poles or the like. Further, the permanent magnet type rotating electric machine shown in Fig. 4 is composed of a four-pole rotor and a six-slot stator. Further, the permanent magnet type rotating electric machine in the present 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, the "axial direction" indicates the direction of the rotation axis of the rotor, the "diameter direction" indicates the radial direction of the rotor, and the "circumferential direction" indicates the circumferential direction of the rotor. The cross-sectional view of the permanent magnet type rotating electric machine according to the present embodiment shown in Fig. 1 is a cross section perpendicular to the rotation axis (the same applies to Figs. 2 to 4 and 6 to be described later). Further, the first embodiment operates as a permanent magnet synchronous motor.

As shown in Fig. 1, the permanent magnet type rotating electric machine 1 is configured by a stator 2 and a rotor 3 that is disposed inside the stator 2 through a specific gap (gap) and that rotates together with a shaft (not shown). The stator 2 is configured by a core back 5 having a ring shape, and 9 teeth 4 projecting from the core back 5 toward the inner side in the radial direction and arranged at equal intervals in the circumferential direction. a stator core 6 and an armature winding 8 or the like that is wound around a concentrated winding of the teeth 4 in a groove 7 between the teeth 4 adjacent to the circumferential direction; the stator 2 is fitted by a heat jacket or It is press-fitted to the frame (for example, a closed container of a compressor, etc.).

That is, the armature winding 8 is wound around the axis of the tooth 4 arranged radially in the radial direction, and in the circumferential direction, the three-phase winding U-phase winding 8a, the V-phase winding 8b, The W-phase windings 8c are arranged with a gap therebetween. Further, the stator 2 is configured such that the stator cores 6 (electromagnetic steel sheets) are stacked in the axial direction, and the grooves 7 are formed by nine (9 slots) between the adjacent teeth 4.

The rotor 3 is composed of a rotor core 12 and six permanent magnets 14 that are disposed in the circumferential direction at equal intervals on the outer peripheral portion side of the rotor core 12, and is a rotor having six poles. A shaft hole 15 is formed in a rotation center portion of the rotor 3, and a cylindrical shaft (not shown) is integrally fixed to the shaft hole 15, and the rotor 3 is rotatably disposed on the inner peripheral surface side of the stator 2 via a gap. .

In the permanent magnet type rotating electric machine 1 of the present embodiment, the number of poles of the rotor 3 is six poles, and the number of slots of the stator 2 is nine slots (6 poles and nine slots), so the pitch θs of the slots 7 is 120 degrees. (The mechanical angle is 40 degrees).

In the permanent magnet type rotating electric machine 1 of the present embodiment, a three-phase alternating current is generated by the armature winding 8 composed of the three-phase windings 8a to 8c, and 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 embedded in the rotor 3 by the rotating magnetic field.

In addition, in order to reduce iron loss such as eddy current loss in the stator core 6 and the rotor core 12 during the operation of the permanent magnet type rotating electric machine 1, the stator core 6 and the rotor core 12 are preferably laminated. The plurality of sheets are formed of a laminate of thin sheets made of a magnetic steel sheet such as a ruthenium plate.

Fig. 2 is a cross-sectional view showing 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 aforementioned rotor core 12 in which a shaft hole 15 is formed at a central portion of its rotation. In the vicinity of the outer peripheral side surface in the rotor core 12, a plurality of rectangular permanent magnet insertion holes 13 having a long cross section are formed (in the first embodiment, the number of poles is six). The plurality of permanent magnet insertion holes 13 are respectively inserted and made of a magnet material such as a rare earth crucible, and are the flat permanent magnets 14 in the shape of a flat plate.

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 is defined as the virtual axis connecting the longitudinal center of the permanent magnet 14 (the center of the cross section) and the center of rotation. The d-axis (flux axis) defines the axis (the axis between the permanent magnets) electrically connected to the d-axis, that is, orthogonal to the electrical angle, as the q-axis.

As shown in Fig. 2, in the present embodiment, in the rotor 3, one permanent magnet 14 is provided for each 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 longer direction of the permanent magnet 14 extends in a geometrically orthogonal direction with respect to the d-axis.

The rotor core 12 of the rotor 3 is provided with a rotor recess 11 recessed on the inner peripheral side on the q-axis between the poles of the adjacent permanent magnets 14. The rotor 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 outer peripheral side of the rotor recessed portion 11, and has an arc-shaped outermost peripheral portion in which the gap length (void) of the teeth 4 of the stator 2 is the shortest g1. That is, the arcuate portion 12a of the magnetic pole surface in the rotor core 12 is formed.

In the present embodiment, the magnetic pole surface of the rotor core 12 has a cut portion 12b connected to an end portion of the arcuate portion 12a, and the arcuate portion 12a is connected to the rotor recess 11 through the cut portion 12b. . The interval length g2 between the cut portion 12b and the teeth 4 of the stator 2 is configured to be wider than the interval length g1 between the arcuate portion 12a and the teeth 4 of the stator 2. Further, in the present embodiment, the cut portion 12b is formed in a straight line shape, but it is not necessarily limited to a straight line shape, and may be a curved surface.

Further, in the present embodiment, the angle θp3 of the arcuate portion 12a in the periphery of the rotation center O of the rotor 3, that is, the angle at which the two ends of the arcuate portion 12a intersect the two axes of the rotation center O Θp3 is an electrical angle of 90° to 120°.

The rotor recess 11 has two straight portions 11b and 11c which are formed in a direction substantially parallel to the radial direction of the permanent magnet 14, and a peripheral end portion of the rotor which is smoothly connected to the two straight portions 11b and 11c. The curved portion 11a; the curved portion 11a is connected between the end portions of the q-axis in the inner peripheral magnetic pole faces of the two permanent magnets adjacent to the two sides of the q-axis. The imaginary straight line 9 between the closest parts is more positioned on the inner side of the rotor. Further, in the present embodiment, the start position of the curved portion 11a is a portion that is substantially at the virtual line 9; however, the position may be at the inner side of the rotor of the virtual straight line 9. In addition, when at least a part of the curved portion 11a is located closer to the inner peripheral side than the virtual straight line 9, the starting position of the curved portion 11a may be located on the outer peripheral side of the virtual straight line 9. .

As described above, in the present embodiment, the bottom portion of the rotor concave portion 11 in the radial direction is deeper than the inner peripheral magnetic pole surface of the permanent magnet 14. In this way, the curved portion 11a is provided in the rotor recess 11, whereby the influence of the stress accompanying the centrifugal force of the rotor in the high speed region can be alleviated. That is, the concentration of the stress accompanying the centrifugal force of the rotor in the rotor recess 11 is alleviated, so that the strength of the rotor 3 for centrifugal force is increased.

Further, in the direction perpendicular to the q-axis, the interval between the two straight portions 11b and 11c is gradually expanded from the inner peripheral side of the rotor toward the outer peripheral side of the rotor. Further, the cross-sectional area of the rotor recess 11 is larger than the cross-sectional area of the cut portion 12b.

In the periphery of the rotation center O of the rotor 3, the angle between the ends of the outer peripheral magnetic pole faces of the permanent magnet 14 constituting one magnetic pole of the rotor 3 is θp1, and the two straight portions 11b of the rotor recess 11 are When the angle between the end portions on the outer peripheral side of the rotor of 11c is θp2, in the present embodiment, the angles θp1 and θp2 are set to satisfy: Such a relationship.

In the present embodiment, as described above, the pitch of the aforementioned grooves 7 in the stator 2 having the winding of the concentrated winding is 120 degrees. Further, each magnetic pole has 1.5 slots (=9 slots/6 poles), so the angle between the q-axis is 180 degrees. For this reason, the electrical angle is "120 ° ≦ θp1 < 180 °" and "0 ° < θp2 ≦ 60 °". Therefore, "0 < θp2 / θp1 ≦ 0.5 (= 60 ° / 120 °)".

Further, according to the review by the inventors of the present invention, in the case where the rotor 3 having the rotor recess 11 having the curved portion 11a is provided, "0.18 ≦ θp2 / θp1" is determined, whereby the q-axis magnetic flux is suppressed. The armature reaction is suppressed, and the torque boosting effect in the high speed domain is obtained.

Further, in the present embodiment, the rotor 3 is on the outer peripheral side of the permanent magnet insertion hole 13 (or the permanent magnet 14) (the arcuate portion 12a in the rotor core 12 and the outer peripheral side of the permanent magnet 14) Between the magnetic pole faces, the plurality of slits 10a to 10d are arranged to be symmetrical with respect to the d-axis on the right and left sides of the specific distance from the d-axis. Further, no slit is provided on the d-axis and the vicinity of the d-axis, and the magnetic flux is easily passed 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 disposed between the slits 10a and 10b and are symmetrical with respect to the d-axis. In the present embodiment, the distance between the slits 10c and 10d disposed closest to the d-axis in the slits 10a to 10d is set to be substantially the minimum width of the teeth 4.

Specifically, in the present embodiment, in the slits 10a to 10d, the direction of the magnetic pole plane of the flat permanent magnet 14 is the geometrically perpendicular direction with respect to the d-axis, and the slit closest to the d-axis The distance between the ends of 10c and 10d is set substantially to the minimum width of the teeth 4.

Further, in order to concentrate the magnetic flux of the permanent magnet 14 to the teeth 4, the slits 10a to 10d are arranged obliquely. In other words, the slits 10a to 10d are inclined toward the outer peripheral side in a direction parallel to the d-axis to the inner side, and have an acute angle with the d-axis. With such slits 10a to 10d, the induced electromotive force waveform can be sinusoidal, and the armature current can be sinusoidal, and the high harmonic magnetic field generated by the interaction between the induced electromotive force and the armature current can be reduced. through. In other words, by suppressing the armature reaction by the slits 10a to 10d, the harmonic component of the magnetic flux in the rotary electric machine can be reduced.

By the way, in the permanent magnet type rotating electric machine 1 for a compressor to which the present embodiment is applied, vibration and noise are often problems. In particular, the armature winding 8 of the concentrated winding is a winding arranged at an electrical angle of 120 degrees, and the high harmonic component such as 5 or 7 times of the magnetic flux in the machine is large, and becomes a vibration. The pulsating torque or the electromagnetic vibration force in the radial direction of the noise is also increased.

Here, a reference example similar to the aforementioned Patent Document 1 is shown in FIG. In the reference example shown in FIG. 4, the distal end portion (tooth end portion) 16 of the tooth 4 in the stator 2 is formed such that its central portion is concentric with the rotor core 12, and both end sides of the tooth distal end portion 16 are provided. It is formed in a straight line, that is, away from the rotor core 12.

With such a configuration, the sinusoidal induced electromotive force waveform can sine the armature current, and the high-harmonic magnetic flux generated by the interaction between the induced electromotive force and the armature current can be reduced, and as a result, Reduce the pulsating torque or the electromagnetic excitation force in the radial direction.

However, when both end sides of the tooth end portion 16 are separated from the rotor 3, the cross-sectional area of the groove 7 becomes small, and the diameter of the wire of the armature winding 8 provided in the groove 7 must be reduced, or This is a problem of reducing the number of turns (winding number) of the armature winding 8 and the like. Therefore, in order to prevent the efficiency from being lowered, the both end sides of the tooth end portion 16 cannot be sufficiently separated from the rotor core 12, and therefore, there is a problem that vibration and noise cannot be sufficiently reduced.

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

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

The stator recessed portion 17 has three straight portions (17a, 17b, and 17c) along the width direction (parallel) of the teeth 4, and two straight portions (17d) that connect the respective end portions of the three straight portions. , 17e) to form. In other words, the stator recess 17 has a first straight portion 17a that is connected to one of the arc portions 5a and that is parallel to the width direction of the teeth 4, and includes the teeth together with the arc portion and is provided The second straight portion 17b that is connected to the arc portion on the other side and that is parallel to the width direction of the tooth is provided on the inner side in the radial direction between the first and second straight portions and is parallel to the width direction of the tooth. The third straight portion 17c, the fourth straight portion 17d connected to one end of the third straight portion 17c and the first straight portion 17a, and the other end of the third straight portion 17c and the second straight portion 17b The fifth straight portion 17e is connected to each other to form a substantially trapezoidal shape.

Moreover, the aforementioned stator recess 17 is not connected to the aforementioned frame. With such a configuration, it is possible to suppress the pulsating torque in the rotary electric machine or the radial electromagnetic exciting force from being transmitted to the frame of the compressor.

Further, the distance between the left and right ends of the inside of the groove 7 of the tooth end portion 16 is defined as L1, the width of the tooth 4 is defined as L2, and the circular arc portion 5a provided on both sides of the stator concave portion 17 and the aforementioned The linear distance (the distance from the portion not in contact with the frame on the back side of the tooth 4) at which the points at which the stator recesses 17 intersect is defined as L3. More specifically, the distance L3 is a point at which one of the arc portions 5a provided on both sides of the stator core portion 5 surrounds the stator recess portion 17 around the stator core 5 and the first straight portion 17a of the stator recess portion 17 And the distance between the other side of the arc portion 5a and the point at which the second straight portion 17b intersects. Thus, when the foregoing L1, L2, and L3 are defined, in the present embodiment, the composition satisfies: L2 < L1 < L3

Such a relationship.

Further, the depth L4 of the stator recess 17 is shorter than the length of the teeth 4 or the thickness of the core back 5, so that the flow of the effective magnetic flux in the rotary electric machine is not lost as much as possible.

As described above, the first embodiment is a permanent magnet type rotating electric machine in which the structure of the rotor 3 described in FIG. 2 and the structure of the stator 2 described in FIG. 3 are combined, whereby the influence of the armature reaction can be sufficiently reduced. Since the high-harmonic component of the magnetic flux in the rotating electrical machine is suppressed, the generation of the pulsating torque or the electromagnetic excitation force in the radial direction can be suppressed, and small size, high efficiency, and low noise can be pursued. Further, it is also possible to suppress the pulsating torque generated in the rotary electric machine or the radial direction electromagnetic exciting force from being transmitted to the frame.

As a result, it is possible to obtain a permanent magnet type rotating electric machine which is excellent in low noise and small in size and high in efficiency. When the permanent magnet type rotating electric machine 1 is used in a compressor constituting a refrigerating cycle, it can be obtained in a small size and high efficiency. It is a low noise compressor.

In other words, according to the present embodiment, it is possible to obtain a permanent magnet type rotating electric machine which can reduce the high-harmonic component of the magnetic flux without reducing the sectional area of the stator, and which is low in noise and small in efficiency. Use its compressor.

[Embodiment 2]

Embodiment 2 of the present invention will be described using FIG. Fig. 5 is a view showing the second embodiment, and is a longitudinal sectional view of a compressor using a permanent magnet type rotating electric machine.

The compressor 20 shown in FIG. 5 includes a compression mechanism unit 21 that reduces the volume of the operating fluid such as a refrigerant, that is, a gas, and a motor unit 22 that drives the compression mechanism unit 21. The motor unit 22 is equipped with the above-described implementation. The permanent magnet type rotating electric machine 1 of Example 1. Since the compressor 20 of the second embodiment is used in a refrigeration cycle apparatus such as an air conditioner, the compression mechanism unit 21 and the motor unit 22 are housed in a cylindrical closed container (frame) 23. Further, in the sealed container 23, R32 refrigerant is sealed as an operating fluid.

The configuration of the compressor 20 shown in Fig. 5 will be described in detail.

The compression mechanism portion 21 and the motor portion 22 are housed in the sealed container 23.

In the present embodiment, the compression mechanism unit 21 is configured by a scroll compression mechanism including a fixed turbine 24 and a swirling turbine 25, and the fixed turbine 24 is fastened to the above by fastening means such as bolts. The frame 26 of the inner surface of the container 23 is sealed.

The fixed turbine 24 is configured by an end plate 24a, a fixed turbine lap portion 24b formed in a spiral shape standing upright on the end plate 24a, a discharge port 24c formed at a substantially central portion of the end plate 24a, and the like. The swirling turbine 25 is configured by an end plate 25a, a spiral swirling turbine lap portion 25b that is formed 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.

The swirling turbine 25 meshes with the fixed turbine 24, and rotates the motor portion (permanent magnet rotating machine) 22 to cause the swirling turbine 25 to rotate by the crank shaft 27 to perform a compression operation.

In other words, the crankshaft 27 is inserted into the shaft hole 15 (see FIGS. 1 and 2) of the rotor 3 formed in the motor unit 22, and is integrally formed with the rotor 3, and a crank is formed at the upper end of the crankshaft 27. Part (eccentric pin part) 27a. Further, the crank portion 27a of the crankshaft 27 is inserted into the boss portion 25c of the swirling turbine 25 to be engaged. The crankshaft 27 is rotatably supported by a sliding bearing (main bearing) 28 provided in the frame 26 and a ball bearing 30 of a lower lower frame 29 provided in the hermetic container 23.

Accordingly, when the motor unit 22 is driven, the crank shaft 27 also rotates, and the crank turbine 27 is rotated by the crank portion 27a. When the swirling turbine 25 starts the swirling motion, the refrigerant gas system of the refrigeration cycle is sucked from the suction pipe 31 into the suction chamber formed on the outer peripheral side of the fixed turbine 24, and is closed therefrom to be formed by the fixed turbine 24 and the swirling turbine 25. After the compression chamber 32, it is compressed together with the swirling motion of the swirling turbine 25 to move to the center side, from the aforementioned discharge port 24c. The discharge chamber is discharged to the upper portion of the sealed container 23.

In other words, the compression chamber located on the outermost diameter side of the compression chamber 32 formed by the fixed turbine 24 and the swirling turbine 25 gradually moves toward the center of the two turbine members 24 and 25 as the swirling motion moves. When the compression chamber 32 reaches the vicinity of the center of the two turbine members 24 and 25, the compression chamber 32 communicates with the discharge port 24c, and the compressed gas system is discharged from the compression chamber 32 through the discharge port 24c to the discharge chamber.

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

Further, the component symbol 8 is an armature winding of the stator 2, the component symbol 37 is a weight, and the component symbol 38 is a power supply terminal. The motor unit 22 including the permanent magnet type rotating electric machine 1 is controlled by an inverter (not shown) provided separately, and is rotated at a rotation speed suitable for the compression operation.

The effects of the compressor of the second embodiment in which the permanent magnet type rotating electric machine of the first embodiment described above is mounted will be described with reference to Table 1. Table 1 shows two realities A test result; one is the actual measurement result of the acoustic test of the noise caused by the compressor 20 of the second embodiment described above; the other is that the basic configuration of the compressor is the same as that of the compressor 20 of the second embodiment, but only The part of the permanent magnet type rotating electric machine of the second embodiment is incorporated in a compressor equipped with a rotating electric machine of the reference example shown in FIG. 4 or a compressor of a conventional permanent magnet type rotating electric machine. The measured results of the auditory test of the noise.

In Table 1, the frequency band of the harsh noise is roughly divided into three of the low range, the middle range, and the high range. The low-range is the frequency band of less than 1 kHz, the mid-range is the frequency band of 1 kHz or more, less than 4 kHz, the high-range is the frequency band of 4 kHz or more, 10 kHz or less.

According to the experiment, it has been found that in the compressor equipped with the conventional permanent magnet type rotating electric machine (hereinafter also referred to as a conventional compressor), the noise component in the middle range, which is particularly problematic, is more prominent. . Further, the compression of the rotary electric machine equipped with the reference example shown in FIG. In the compressor (hereinafter also referred to as the compressor of the reference example), the noise component of the low range and the high range is reduced in comparison with the conventional compressor, but the acoustic component of the middle range is acoustic. There are some changes in the above, but they cannot be fully reduced.

On the other hand, the compressor of the second embodiment in which the rotary electric machine according to the first embodiment described above is mounted, that is, the compressor in which the rotor shape shown in FIG. 2 and the stator shape shown in FIG. 3 are combined is mounted. In the case of the noise component of the low range and the high range, compared with the compressor of the reference example, it was confirmed that in addition to the same noise reduction effect, the noise component which can greatly reduce the midrange is also added.

In the compressor of the reference example, as a high-harmonic component of the magnetic flux in the rotating electrical machine, a high-harmonic component of 5 times and 7 times of low-order harmonics was observed, and 25 times were observed. Or a high-order harmonic component with a comparison of 27 components. However, it has been found that as a harmonic component of the magnetic flux in the rotating electrical machine, the harmonic component of the midrange of the comparison of the 11th or 13th component, the 15th or the 17th component is hardly reduced.

On the other hand, in the case of the compressor of the second embodiment in which the rotary electric machine of the first embodiment is mounted, it is possible to reduce the low-order and high-order high magnetic flux in the rotary electric machine similarly to the compressor of the reference example. The harmonic components, and also the high harmonic components of the comparative midrange, can be significantly reduced compared to the compressor of the reference example. The reason is that in the case of the compressor of the second embodiment, the pulsating torque and the radial electromagnetic exciting force transmission in the rotary electric machine can be suppressed under the high harmonic component of the magnetic flux in the rotary electric machine. To the closed container (frame) 23 of the compressor 20, and thus The result.

Further, 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. As described above, according to the compressor of the second embodiment, the noise component of the midrange in which the hearing is particularly problematic can be greatly reduced, and the overall noise value can be reduced.

Further, in the second embodiment, as described above, by using the permanent magnet type rotating electric machine 1 of the first embodiment described above to the compression chamber 20, the compressor 20 which is low in noise and small in efficiency can be obtained. That is, the foregoing permanent magnet type rotating electric machine 1 has the rotor 3 of the configuration illustrated in Fig. 2, and the torque of the permanent magnet type rotating electric machine 1 can be made larger than conventional ones, and particularly large in the high speed range. Further, it is also possible to suppress a decrease in the power factor due to the influence of the armature reaction, and it is possible to suppress the torque drop in the re-high speed range. For this reason, it is possible to pursue high efficiency or miniaturization of a permanent magnet type rotating electric machine.

By using such a compact and high-efficiency permanent magnet type rotating electric machine, it is possible to achieve efficiency improvement of the compressor and energy saving. Moreover, the high-speed operation of the compressor is possible, and the operating range can be expanded.

Further, in the conventional air conditioner, there are many cases in which the R410A refrigerant is sealed in the hermetic container 23, and the ambient temperature of the permanent magnet type rotating electric machine is 80 ° C or more. In the present embodiment, the ambient temperature is further increased by using the R32 refrigerant having a smaller global warming coefficient. The permanent magnet 14, especially the neodymium magnet, is at a high temperature, and the residual magnetic flux density is lowered. While the same output is output and the armature current is increased, the efficiency of the compressor of the permanent magnet type rotating electric machine 1 of the above-described first embodiment can be suppressed.

Further, in the second embodiment, R32 is used as the refrigerant. However, the refrigerant such as R32 or He is larger than the refrigerant such as R22, R407C, and R410A, and the leakage from the gap in the compressor is large, especially at a low speed. At the time of operation, the ratio of leakage to the circulation amount becomes large, and the efficiency is lowered. In order to improve the efficiency at a low circulation amount (low speed operation), the compression mechanism unit can be miniaturized, and the leakage speed can be reduced in order to obtain the same circulation amount and increase the rotation speed. Further, it is desirable to increase the maximum speed in order to ensure the maximum amount of circulation.

On the other hand, by determining the compressor in which the permanent magnet type rotating electric machine 1 of the first embodiment described above is mounted, the maximum torque and the maximum number of revolutions can be increased, and the loss in the high speed range can be reduced. As described above, the compressor of the second embodiment is particularly effective when a refrigerant such as R32 or He which is easily leaked is used as the refrigerant, and efficiency can be improved.

Further, according to the present embodiment, as shown in Fig. 3, a large-area stator recess 17 is provided around the outer periphery of the stator 2 in the permanent magnet type rotating electric machine 1, and the peripheral surface along the inner periphery of the closed container (frame) 23 is reached. The lubricating oil on the upper surface of the stator 2 easily passes through the stator recess 17 described above. As a result, it is also possible to reduce the oil breakage in which the amount of lubricating oil inside the compressor is insufficient during high-speed operation.

Further, in the second embodiment, R32 is used as the refrigerant, but the present invention does not limit the type of the refrigerant. Moreover, the compressor is in Figure 5 In the example, a turbo compressor is used. However, a compressor having another compression mechanism, such as a rotary compressor, can also be applied to the present invention.

[Example 3]

Embodiment 3 of the present invention will be described using FIG. Fig. 6 is a cross-sectional view showing the shape of a rotor of a permanent magnet type rotating electric machine according to a third embodiment, and corresponds to Fig. 2;

In FIG. 6, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

In the third embodiment, unlike the rotor 3 shown in Fig. 2 of the first embodiment, each of the magnetic poles of the rotor 3A is provided with two permanent magnets 14A. Further, in the cross section shown in FIG. 6, the two permanent magnets 14A are arranged in a V shape with a convex shape with respect to the shaft hole 15. In other words, the cross-sections of the two permanent magnets 14A are the same as those of the first embodiment. However, the d-axis is used as the axis of symmetry and is arranged in a convex V-shape toward the center of rotation O of the rotor 3. Through this, the pursuit of high torque.

Further, in the third embodiment, the other configuration of the rotor 3A 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 respective angles θp1, θp2, θp3, and the like in the rotor 3A are also similar.

A permanent magnet type rotating electric machine in which the rotor 3A of the third embodiment and the stator 2 of the structure illustrated in Fig. 3 of the first embodiment are combined, whereby the rotary electric machine due to the influence of the armature reaction can be sufficiently reduced The high harmonic component of the internal magnetic flux, therefore, suppressing the pulsating torque or the electromagnetic excitation in the radial direction The generation of force can pursue small size, high efficiency, and low noise. Further, it is also possible to suppress the pulsating torque generated in the rotary electric machine or the radial direction electromagnetic exciting force from being transmitted to the frame.

Further, in the third embodiment, as in the first embodiment, it is possible to suppress the torque drop in the high speed range, and from this point, the high efficiency or miniaturization of the permanent magnet type rotating electric machine is possible, and it is possible to obtain The same effects as in the first embodiment described above.

Further, the present invention is not limited to the above-described embodiments, and includes various modifications. Further, the above-described embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to the configurations described above.

1‧‧‧ Permanent magnet rotary motor (drive motor)

2‧‧‧stator

3, 3A‧‧‧ rotor

4‧‧‧ teeth

5‧‧‧ core back

5a‧‧‧Arc Department

5b‧‧‧ stator recess

6‧‧‧ Stator core

7‧‧‧ slot

8‧‧‧ Armature winding

8a‧‧‧U phase winding

8b‧‧‧V phase winding

8c‧‧‧W phase winding

9‧‧‧ imaginary straight line

10a, 10b, 10c, 10d‧‧‧ slits

11‧‧‧Rotor recess

11a‧‧‧ Curve Department

11b, 11c‧‧‧ Straight line

12‧‧‧Rotor core

12a‧‧‧Arc-shaped part

12b‧‧‧cutting department

13, 13A‧‧‧ permanent magnet insertion hole

14, 14A‧‧‧ permanent magnets

15‧‧‧Axis hole

16‧‧‧ teeth end

17‧‧‧ stator recess

17a‧‧‧1st straight line

17b‧‧‧2nd straight line

17c‧‧‧3rd straight line

17d‧‧‧4th straight line

17e‧‧‧5th straight line

20‧‧‧Compressor

21‧‧‧Compression Mechanism Department

22‧‧‧Electric Motors Department

23‧‧‧Contained container

24‧‧‧Fixed turbine

24a‧‧‧End board

24b‧‧‧Fixed Turbine Joints

24c‧‧‧Exporting

25‧‧‧Swing Turbine

25a‧‧‧End board

25b‧‧‧ gyro turbine lap

25c‧‧‧ raised parts

26‧‧‧ box

27‧‧‧ crankshaft

27a‧‧‧ crank

28‧‧‧Sliding bearings (main bearings)

29‧‧‧ Lower frame

30‧‧‧Ball bearings

31‧‧‧Inhalation tube

32‧‧‧Compression room

33‧‧‧ gas passage

34‧‧‧Spit tube

35‧‧‧ Oil Storage Department

36‧‧‧ oil hole

37‧‧‧weight

38‧‧‧Power terminal

Fig. 1 is a cross-sectional view showing a first embodiment of a permanent magnet type rotating electric machine according to the present invention.

Fig. 2 is a cross-sectional view showing the shape of a rotor of the permanent magnet type rotating electric machine shown in Fig. 1 .

Fig. 3 is a cross-sectional view of an essential part showing a stator core shape of a stator of the permanent magnet rotating electric machine shown in Fig. 1 .

Fig. 4 is a cross-sectional view showing a reference example of a permanent magnet type rotating electric machine.

Fig. 5 is a view showing a second embodiment of the present invention, and is a longitudinal sectional view of a compressor using a permanent magnet type rotating electric machine.

Fig. 6 is a cross-sectional view showing a shape of a rotor of a permanent magnet type rotating machine, showing a third embodiment of the present invention, and is a view corresponding to Fig. 2 .

Claims (14)

A permanent magnet type rotating electric machine comprising: a stator having a ring-shaped core back, a plurality of teeth protruding from the core back toward the inner side in the radial direction and arranged in the circumferential direction, and having a plurality of teeth formed between the teeth a slotted stator core, and an armature winding wound around the teeth disposed in the slot, and fixed to the frame; and a rotor having a rotor core and embedded in the rotor core And a plurality of permanent magnets in the circumferential direction are disposed, and the stator is configured to be freely rotatable via the gap; and the stator is provided with: an outer peripheral side of the groove formed in the core back and fixed to the frame a circular arc portion and a stator concave portion formed on an outer peripheral side of the tooth in the core back; the stator concave portion having a first straight portion connected to one of the circular arc portions and parallel to a width direction of the tooth And the second straight portion that is connected to the circular arc portion provided on the other side and that is parallel to the width direction of the tooth, and is the first and second straight The third straight portion that is located further in the radial direction than the first and second straight portions and that is parallel to the width direction of the teeth, and one end of the third straight portion and the first straight portion are provided between the portions. a fourth straight portion connected to each other and a fifth straight portion connected to the other end of the third straight portion and the second straight portion, and having a substantially trapezoidal shape; and a groove inside the tooth end portion of the tooth The distance between the two ends L1, when the width of the tooth is L2, and the linear distance connecting the points where the circular arc portion provided on both sides of the stator concave portion and the stator concave portion are connected to each other is L3, L2 < L1 < The relationship of L3. The permanent magnet rotating electrical machine according to claim 1, wherein when the magnetic flux axis of the permanent magnet is the d-axis and the axis orthogonal to the d-axis electrical angle is the q-axis, the rotor core has: a rotor recess recessed to the inner peripheral side on the q-axis; the rotor recess is formed by two straight portions along the thickness direction of the permanent magnet, and end portions on the inner peripheral side of the rotor connected to the two straight portions In the periphery of the rotation center O of the rotor, the angle between the end portions of the magnetic pole faces on the outer peripheral side of the permanent magnet is θp1, and the end portions on the outer peripheral side of the rotor of the two straight portions are When the angle between the angles is θp2, the relationship between the angle θp1 and the angle θp2 is 0.18 ≦ θp2 / θp1 ≦ 0.5. The permanent magnet type rotating electric machine according to claim 2, wherein the curved portion is opposite to the q-axis opposite to the inner peripheral side magnetic pole surface of the two permanent magnets on the both sides of the q-axis unit The imaginary line between them is more positioned on the inner side of the rotor. The permanent magnet type rotating electric machine according to claim 2, wherein the interval between the two straight portions is expanded from the inner side of the rotor toward the outer peripheral side of the rotor in a geometrically orthogonal direction with respect to the q-axis. The permanent magnet type rotating electric machine according to claim 2, wherein the magnetic pole face in the rotor core has an arcuate portion. The permanent magnet type rotating electric machine according to claim 5, wherein a plurality of slits are symmetrically disposed with respect to the d-axis between the arc-shaped portion and the outer peripheral-side magnetic pole surface of the permanent magnet. The permanent magnet type rotating electric machine according to claim 5, wherein the magnetic pole surface of the rotor core has a cut portion connected to an end portion of the arcuate portion, and the arcuate portion is connected to the aforementioned portion through the cut portion In the rotor recess, the gap between the cut portion and the stator is wider than the gap between the arcuate portion and the stator. The permanent magnet type rotating electric machine according to claim 7, wherein the cut portion is formed on both sides of the arc-shaped portion, and the cut portions are respectively connected to the two straight portions respectively forming the rotor recess portion. The outer peripheral side end portion of the rotor of the straight portion of this side is formed Straight. The permanent magnet type rotating electric machine according to claim 7, wherein the sectional area of the rotor recess is larger than the sectional area of the cut portion. The permanent magnet type rotating electric machine according to claim 5, wherein an angle θp3 of the arcuate portion is an angle of 90° or more and 120° or less in the periphery of the rotation center O of the rotor. A permanent magnet rotating electrical machine according to claim 2, wherein a ratio of a number of poles of said rotor to a number of slots of said stator is 2:3. The permanent magnet type rotating electric machine according to claim 2, wherein the permanent magnet embedded in the rotor core is constituted by two permanent magnets of each pole of the rotor, and the two permanent magnets are the aforementioned d The shaft serves as a symmetry axis and is arranged in a convex V shape toward the center of rotation O of the rotor. A compressor comprising: a compression mechanism that compresses an operating fluid, that is, a volume of a gas, and a permanent magnet type rotating electrical machine that drives the compression mechanism; wherein the permanent magnet rotating electrical machine is equipped with a request item 1~ A permanent magnet type rotating electric machine according to any one of the twelve. The compressor of claim 13, wherein the compressor is sealed with R32 refrigerant.