WO2022176307A1

WO2022176307A1 - Permanent magnet synchronous motor, compressor, and device

Info

Publication number: WO2022176307A1
Application number: PCT/JP2021/043826
Authority: WO
Inventors: 典禎西山; 行雄尾崎
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2021-02-17
Filing date: 2021-11-30
Publication date: 2022-08-25
Also published as: CN116368717A; JPWO2022176307A1

Abstract

In this permanent magnet synchronous motor 3 of the present invention, a stator 3b has an annular stator yoke 31 centered on a rotational axis 8, a plurality of stator teeth 32 extending from the stator yoke 31 toward a rotor 3a, and slots 40 formed between the stator teeth 32, wherein windings 50 are disposed in the slots 40 and the stator teeth 32 each have: a stator tooth base 32a around which the winding 50 is wound; and a stator tooth end portion 32b forming, at the end of the stator tooth base 32a, a facing surface 35 facing the rotor 3a. At least two small holes 70a, 70b are arranged side by side in a direction along the facing surface 35 in the stator tooth end portion 32b, thereby being able to reduce force variation in the tooth direction (radial direction) and obtain low noise due to low vibration and high efficiency.

Description

Permanent magnet synchronous motors, compressors, and equipment

The present invention relates to a permanent magnet synchronous motor, a compressor using this permanent magnet synchronous motor, and equipment using this compressor.

Patent Literature 1 discloses a rotating electrical machine capable of achieving both suppression of a decrease in circumferential torque to be generated by the rotating electrical machine and reduction of radial electromagnetic excitation force generated in the rotating electrical machine.
In Patent Literature 1, an axial communication hole is provided in the vicinity of the air gap in the tooth portion to suppress a decrease in circumferential torque.

JP 2015-96022 A

The electromagnetic excitation force acting on the stator teeth changes depending on the rotational position of the rotor and the energized current, and it was discovered that the radial force that strengthens the electromagnetic excitation force is maximized on the anti-rotation side from the center of the teeth. However, it is important not to reduce the torque as the flux flow is adjusted.

The present invention provides a permanent magnet synchronous motor capable of reducing variations in radial force, realizing low noise due to low vibration, and high efficiency, and air conditioners, dehumidifiers, and heat pump hot water heaters using this permanent magnet synchronous motor. machines, refrigerators (household refrigerators, commercial refrigerators), ice machines, showcases, heat pump type washer/dryers, vending machines, etc., and equipment using these compressors. With the goal.

A permanent magnet synchronous motor according to claim 1 of the present invention has a rotor arranged to be rotatable about a rotation axis, a stator arranged with an air gap between the rotor and the fixed motor. The element includes an annular stator yoke centered on the rotating shaft, a plurality of stator teeth extending from the stator yoke toward the rotor, and slots formed between the stator teeth. windings are arranged in the slots, and the stator teeth are provided with stator teeth bases around which the windings are wound, and fixed surfaces that face the rotor at tips of the stator teeth bases. At least two small holes are arranged side by side in the direction along the facing surface in the stator tooth tip.
According to a second aspect of the present invention, there is provided the permanent magnet synchronous motor according to the first aspect, wherein the circumferential width center of the stator tooth base is defined as a virtual center line of the tooth base, and a plurality of small holes are formed. The plurality of small holes are arranged such that the imaginary center of the group is in the anti-rotating direction of the rotor from the imaginary center line of the tooth base.
According to a third aspect of the present invention, there are provided three or more small holes in the permanent magnet synchronous motor according to the first or second aspect.
The present invention according to claim 4 is the permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the cross-sectional shape of at least one of the small holes is quadrangular, triangular, polygonal, or elliptical. It is characterized by having a shape.
According to a fifth aspect of the present invention, in the permanent magnet synchronous motor according to any one of the first to fourth aspects, the small holes are arranged at different distances from the facing surface. characterized by
The present invention according to claim 6 is the permanent magnet synchronous motor according to any one of claims 1 to 5, wherein the respective small holes are arranged to be inclined with respect to the virtual center line of the tooth base. It is characterized by arranging
The present invention according to claim 7 is the permanent magnet synchronous motor according to any one of claims 1 to 6, wherein the stator includes a plurality of stator cores laminated in the axial direction of the rotating shaft. The small holes are formed in some of the stator cores, and the small holes are not formed in the other stator cores.
A compressor according to an eighth aspect of the present invention uses the permanent magnet synchronous motor of the seventh aspect, the permanent magnet synchronous motor and the compression mechanism section are connected by a shaft, and the compression mechanism section is provided with the small compressor. The stator core having no holes is arranged, and the stator core having the small holes is arranged on the side away from the compression mechanism.
A compressor of the present invention according to claim 9 uses the permanent magnet synchronous motor according to any one of claims 1 to 7, and connects the permanent magnet synchronous motor and the compression mechanism with a shaft, The refrigerant is compressed by the compression mechanism.
According to claim 10, the apparatus of the present invention is characterized in that the compressor, condenser, decompression device, and evaporator according to

claim

8 or 9 are annularly connected by piping.

According to the present invention, it is possible to adjust the flow of magnetic flux, maintain the same torque as when no small holes are provided, reduce fluctuations in radial force, and realize low noise due to low vibration and high efficiency. can be done.

FIG. 1 is a longitudinal sectional view showing the configuration of a compressor using a permanent magnet synchronous motor according to one embodiment of the present invention; 1 is a configuration diagram of a permanent magnet synchronous motor according to the present embodiment; FIG. FIG. 2 is a configuration diagram showing the main part of the stator core of the permanent magnet synchronous motor according to the present embodiment; Graph showing tooth direction (radial direction) force and torque according to the present embodiment Graph showing the relationship between torque and fluctuation width of tooth direction (radial direction) force with respect to small hole arrangement angle FIG. 3 is a configuration diagram of a main part showing a stator core of a permanent magnet synchronous motor according to another embodiment of the present invention; FIG. 3 is a configuration diagram of a main part showing a stator core of a permanent magnet synchronous motor according to another embodiment of the present invention; FIG. 3 is a block diagram showing the essential parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention; Graph showing tooth direction (radial direction) force and torque according to the embodiment shown in FIG. FIG. 3 is a block diagram showing the essential parts of a compressor using a permanent magnet synchronous motor according to still another embodiment of the present invention;

In the permanent magnet synchronous motor according to the first embodiment of the present invention, at least two small holes are arranged side by side in the direction along the facing surface at the tips of the stator teeth. According to the present embodiment, it is possible to adjust the flow of magnetic flux, maintain torque equivalent to that in the case where small holes are not provided, reduce variations in force in the tooth direction (radial direction), reduce noise due to low vibration, High efficiency can be achieved.

According to a second embodiment of the present invention, in the permanent magnet synchronous motor according to the first embodiment, the center of the width dimension of the stator tooth base in the circumferential direction is defined as the imaginary center line of the tooth base, and a small magnet composed of a plurality of small holes is provided. A plurality of small holes are arranged such that the imaginary center of the hole group is in the anti-rotational direction of the rotor from the imaginary center line of the tooth base. According to this embodiment, particularly, the small hole group can be arranged at an arrangement angle at which the force in the tooth direction (radial direction) is locally increased, and it is possible to both reduce fluctuations in the tooth direction (radial direction) force and suppress torque reduction. .

According to the third embodiment of the present invention, the permanent magnet synchronous motor according to the first or second embodiment has three or more small holes. According to this embodiment, it is possible to easily adjust the flow of magnetic flux, maintain the same torque as when no small holes are provided, reduce fluctuations in force in the direction of the teeth (radial direction), and reduce noise due to low vibration. , high efficiency can be achieved.

According to a fourth embodiment of the present invention, in the permanent magnet synchronous motor according to any one of the first to third embodiments, the cross-sectional shape of at least one small hole is quadrangular, triangular, polygonal, or elliptical. and According to this embodiment, since the square, triangle, polygon, or ellipse has a straight portion, the minimum distance between the small holes can be stably secured, and the magnetic resistance due to processing errors can be reduced. variation can be suppressed.

According to a fifth embodiment of the present invention, in the permanent magnet synchronous motor according to any one of the first to fourth embodiments, the respective small holes are arranged at different distances from the facing surface. . According to this embodiment, the arrangement can be made according to the magnetic flux acting on the stator accompanying the rotation of the rotor and the force in the direction of the stator teeth (radial direction), and the flow of the magnetic flux can be adjusted. Fluctuations in teeth direction (radial direction) force can be reduced while maintaining torque equivalent to the case where is not provided.

According to a sixth embodiment of the present invention, in the permanent magnet synchronous motor according to any one of the first to fifth embodiments, the respective small holes are arranged to be inclined with respect to the virtual center line of the tooth base. It is a thing. According to this embodiment, the magnetic flux flow around the small hole can be changed.

According to a seventh embodiment of the present invention, in the permanent magnet synchronous motor according to any one of the first to sixth embodiments, the stator includes a plurality of stator cores laminated in the axial direction of the rotating shaft. Some stator cores are formed with small holes and other stator cores are not formed with small holes. According to the present embodiment, since the phase of the torque pulsation is shifted between the stator core without the small holes and the stator core with the small holes, the torque pulsation can be reduced by stacking these stator cores. can be reduced.

A compressor according to an eighth embodiment of the present invention uses the permanent magnet synchronous motor according to the seventh embodiment. A stator core with no holes is arranged, and a stator core with small holes is arranged on the side away from the compression mechanism. According to the present embodiment, the rigidity of supporting the rotor is increased by arranging the stator core with small variation in force in the tooth direction (radial direction) on the side away from the compression mechanism.

A compressor according to a ninth embodiment of the present invention uses the permanent magnet synchronous motor according to any one of the first to seventh embodiments, connects the permanent magnet synchronous motor and the compression mechanism with a shaft, and compresses the motor. The refrigerant is compressed by the mechanism. According to this embodiment, it is possible to realize a compressor with low noise due to low vibration and high efficiency without lowering torque.

A device according to the tenth embodiment of the present invention is obtained by annularly connecting the compressor, condenser, decompression device, and evaporator according to the eighth or ninth embodiment by piping. According to the present embodiment, it is possible to realize low noise due to low vibration and highly efficient equipment without lowering torque.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing the configuration of a compressor using a permanent magnet synchronous motor according to this embodiment.
A compressor 10 according to this embodiment includes a compression mechanism 2 for compressing a refrigerant gas and a permanent magnet synchronous motor 3 for driving the compression mechanism 2 in a sealed container 1 .
The inside of the closed container 1 is divided into one container internal space and the other container internal space by the compression mechanism part 2 . A permanent magnet synchronous motor 3 is arranged in the other space inside the container.
The other space inside the container is divided by the permanent magnet synchronous motor 3 into a space on the compression mechanism side and a space on the oil storage side. A storage oil portion 4 is arranged in the storage oil side space.
A suction pipe 5 and a discharge pipe 6 are fixed to the sealed container 1 by welding. The suction pipe 5 and the discharge pipe 6 are connected to the outside of the sealed container 1 and connected to the members constituting the refrigeration cycle. The suction pipe 5 introduces the refrigerant gas from the outside of the sealed container 1, and the discharge pipe 6 discharges the refrigerant gas to the outside of the sealed container 1 from one inner space of the container.

The main bearing member 7a is fixed in the sealed container 1 by welding, shrink fitting, or the like, and supports a shaft 8 (rotating shaft of the rotor 3a). One side of the shaft 8 is supported by the main bearing member 7a, and the other side is supported by the bearing 7b. A fixed scroll 2a is bolted to the main bearing member 7a. The orbiting scroll 2b meshing with the fixed scroll 2a is sandwiched between the main bearing member 7a and the fixed scroll 2a. The fixed scroll 2 a and the orbiting scroll 2 b constitute a scroll-type compression mechanism 2 .
A rotation restraint mechanism 9 such as an Oldham ring is provided between the orbiting scroll 2b and the main bearing member 7a. The rotation restraint mechanism 9 prevents rotation of the orbiting scroll 2b and guides the orbiting scroll 2b to perform circular orbital motion. The orbiting scroll 2 b is eccentrically driven by an eccentric shaft portion 8 a provided at the upper end of the shaft 8 . Due to this eccentric drive, the compression chamber formed between the fixed scroll 2a and the orbiting scroll 2b moves from the outer circumference toward the central portion of the compression mechanism section 2, and compresses by reducing the volume.

The permanent magnet synchronous motor 3 has a rotor 3a rotatably arranged around a rotating shaft 8, and a stator 3b arranged with an air gap between the rotor 3a.

Refrigerant is sucked into the compression mechanism portion 2 from the suction pipe 5 and compressed in the compression mechanism portion 2 . After that, the refrigerant is discharged from the discharge pipe 6 .
In the apparatus according to this embodiment, a compressor 10, a condenser 61, a decompression device 62, and an evaporator 63 are annularly connected by piping. The condenser 61 condenses the refrigerant discharged from the discharge pipe 6, the decompression device 62 decompresses the condensed refrigerant, and the evaporator 63 evaporates the decompressed refrigerant.
The refrigerant evaporated by the evaporator 63 is returned to the compressor 10 through the suction pipe 5 .

2A and 2B are diagrams showing the configuration of the permanent magnet synchronous motor according to the present embodiment, FIG. 2A being a cross-sectional view of the permanent magnet synchronous motor mounted in the compressor shown in FIG. 1, and FIG. 2(c) is a cross-sectional view showing a state in which the sealed container and the windings are removed from FIG. 2(a); FIG.
The rotor 3 a is fixed to the shaft 8 and the stator 3 b is fixed to the closed container 1 . In the compressor 10 according to this embodiment, the rotation axis of the rotor 3a is the shaft 8. As shown in FIG.
The rotor 3a is made of a magnetic material, and is provided with a plurality of slits inside, and permanent magnets 11 are arranged in each of these slits.
The stator 3b is constructed by laminating a plurality of stator cores 30 in the axial direction of the rotating shaft 8 of the rotor 3a. The stator core 30 includes an annular stator yoke 31 centered on the rotation axis 8 of the rotor 3a, a plurality of stator teeth 32 extending from the stator yoke 31 toward the rotor 3a, and a stator tooth 32 and a slot 40 formed between them. A winding 50 is arranged in the slot 40 .

FIG. 3 is a schematic diagram showing the stator core of the permanent magnet synchronous motor according to this embodiment.
The stator teeth 32 of the stator core 30 according to this embodiment consist of a stator tooth base 32a around which the winding 50 (see FIG. 2) is wound via an insulating material (not shown), and a tip of the stator tooth base 32a. and a stator tooth tip portion 32b forming a surface 35 facing the rotor 3a (see FIG. 2).
The stator tooth tip portions 32b are formed to protrude to both sides of the width dimension t in the circumferential direction of the stator tooth base portions 32a.
At least two

small holes

70a and 70b are arranged side by side in the direction along the facing surface 35 in the stator tooth tip portion 32b. Here, the

small holes

70a and 70b are for increasing the magnetic resistance, and if they are non-magnetic, the effect is high, and even the gaps may be filled with resin.
By arranging these

small holes

70a and 70b, it is possible to adjust the flow of the magnetic flux, and while maintaining the same torque as when the small holes are not provided, it is possible to reduce fluctuations in force in the direction of the teeth (radial direction), thereby reducing vibration. Low noise and high efficiency can be achieved.

Assuming that the center of the circumferential width dimension t of the stator tooth base portion 32a is the tooth base imaginary center line A, the imaginary center 70x of the small hole group 70 consisting of the plurality of

small holes

70a and 70b is rotated from the tooth base imaginary center line A. A plurality of

small holes

70a and 70b are arranged so as to be in the opposite direction of rotation of the element 3a.
By arranging the plurality of

small holes

70a and 70b in this way, the small hole group 70 can be arranged at an arrangement angle at which the tooth direction (radial direction) force is locally increased, and the tooth direction (radial direction) force It is possible to achieve both reduction of fluctuation in torque and suppression of torque drop.
For example, in the 6-pole 9-teeth permanent magnet synchronous motor 3, a plurality of small rotors are arranged so that the virtual center 70x is shifted from the tooth base virtual center line A by about 2° to 3° in the anti-rotation direction of the rotor 3a. Preferably,

holes

70a, 70b are provided.
Assuming that the diameter of the small hole 70a is 70at and the diameter of the small hole 70b is 70bt, the diameter 70at and the diameter 70bt are 1 mm or more, the diameter 70at + the diameter 70bt ≤ the width dimension t/2, and the distance between the small hole 70a and the small hole 70b. The distance between the small holes 70a and the facing surface 35 is preferably 0.5 mm or more, the distance between the small holes 70b and the facing surface 35 is preferably 0.5 mm or more, and the distance between the small holes 70b and the facing surface 35 is preferably 0.5 mm or more.

FIG. 4 is a graph showing tooth direction (radial direction) force and torque according to this embodiment.
FIG. 4(a) shows the relationship between the tooth direction (radial direction) force acting on one stator tooth tip portion 32b and the rotation angle of the rotor 3a. The conventional example does not have small holes.
As the rotor 3a rotates, the stator tooth tip portions 32b receive a tooth direction (radial direction) force of a periodic component corresponding to the number of rotor magnetic poles. This embodiment is a 6-pole motor, and the tooth direction (radial direction) force acting on one stator tooth tip portion is a tooth direction (radial direction) force having one periodic component at a rotation angle of 60°.
In this embodiment, the motor is a three-phase motor, and the fluctuation phase of the force acting on the stator tooth tip portion 32b is 120° in electrical angle and 40° in rotation angle in the tooth direction (radial direction). .
A large fluctuation range of the force in the direction of the teeth (radial direction) causes the vibration of the stator teeth 32 to be large and the vibration of the motor to be large. Vibration of typical rotary compressors and scroll compressors is a major factor.
A low-vibration motor and compressor 10 can be realized by reducing the variation width of the teeth direction (radial direction) force.
The tooth direction (radial direction) force does not uniformly act on the stator tooth tip portions 32b, and the location where the force acts locally changes as the rotor 3a rotates.
According to this embodiment, as shown in FIG. 4(a), it is possible to effectively reduce the tooth direction (radial direction) force acting locally as the rotor 3a rotates. The fluctuation force ratio in the teeth direction (radial direction) is 86% compared to the conventional example.

On the other hand, as shown in FIG. 4(b), when the torque of the conventional example and the torque of this embodiment are compared, the maximum and minimum values of the torque of this embodiment are increased, but the average torque is the same as that of the conventional motor. It turns out that

FIG. 5 is a graph showing the relationship between the variation width of force in the tooth direction (radial direction) and the torque with respect to the arrangement angle of the small holes. In FIG. 5, the arrangement of the two

small holes

70a and 70b shown in this embodiment is changed. The arrangement angle of the small holes on the imaginary center line A of the stator teeth base is 0°, the rotation direction side is indicated by a negative angle, and the half-rotation direction side is indicated by a positive angle.
As shown in FIG. 5, when the arrangement angles of the

small holes

70a and 70b are changed, the fluctuation width of the tooth direction (radial direction) force and the torque change. Here, it is effective to reduce the vibration to reduce the fluctuation width of the teeth direction (radial direction) force.
When the two

small holes

70a and 70b are arranged in the A section (approximately -5° to 9°) shown in FIG. 5, the fluctuation width of the tooth direction (radial direction) force is reduced. In particular, when the

small holes

70a and 70b are arranged at about 3° in the anti-rotational direction, the effect of reducing the variation width of the force in the teeth direction (radial direction) is great.
On the other hand, the torque is equivalent to no -3° to 7° perforation.
Therefore, by arranging the

small holes

70a and 70b about 3° in the counter-rotational direction from the virtual center line A of the tooth base, both low vibration and high torque can be achieved.

6 and 7 are main configuration diagrams showing stator cores of permanent magnet synchronous motors according to other embodiments, respectively. Since the configuration other than the small holes is the same as that of the above embodiment, the description is omitted.
Three

small holes

70a, 70b, and 70c are provided in the stator tooth tip portion 32b of the stator core 30 shown in FIG. 6(a).
Thus, three or more

small holes

70a, 70b, and 70c may be provided. By providing three or more

small holes

70a, 70b, 70c, it is easy to adjust the flow of the magnetic flux, and while maintaining the same torque as when the

small holes

70a, 70b, 70c are not provided, the tooth direction (radial direction) Force fluctuations can be reduced, and low noise due to low vibration and high efficiency can be achieved.

Small holes

71a and 71b having a square cross-sectional shape are provided in the stator tooth tip end portion 32b of the stator core 30 shown in FIG. 6(b). FIG. 6A shows the case where two

small holes

71a and 71b are provided, but three or more small holes may be provided.

Small holes

72a and 72b having a triangular cross-sectional shape are provided in stator tooth tip portions 32b of the stator core 30 shown in FIG. FIG. 6(c) shows a case where two

small holes

72a and 72b are provided, but three or more small holes may be provided.

Small holes

72a and 72b having a triangular cross-sectional shape are provided in stator tooth tip portions 32b of the stator core 30 shown in FIG. FIG. 6(d) shows a case where two

small holes

72a and 72b are provided, but three or more small holes may be provided.

Small holes

72a and 72b having a triangular cross-sectional shape are provided in the tip end portion 32b of the stator teeth of the stator core 30 shown in FIG. 6(e). The small hole 72b has a triangular vertex on the facing surface 35 side. FIG. 6(e) shows a case where two

small holes

72a and 72b are provided, but three or more small holes can also be provided.
6(b) shows the

small holes

71a and 71b having a square cross-sectional shape, and FIGS. 6(c) to 6(e) show the

small holes

72a and 72b having a triangular cross-sectional shape. , the cross-sectional shape may be other polygons.

Small holes

73a and 73b having an elliptical cross-sectional shape are provided in stator tooth tip portions 32b of the stator core 30 shown in FIG. FIG. 7(a) shows the case where two

small holes

73a and 73b are provided, but three or more small holes may be provided.

Small holes

73a and 73b having an elliptical cross-sectional shape are provided in the stator tooth tip portion 32b of the stator core 30 shown in FIG. FIG. 7(b) shows a case where two

small holes

73a and 73b are provided, but three or more small holes may be provided.

Small holes

73a and 73b having an elliptical cross-sectional shape are provided in the stator tooth tip portion 32b of the stator core 30 shown in FIG. It is in the inclined direction. FIG. 7(c) shows a case where two

small holes

73a and 73b are provided, but three or more small holes may be provided.

At least one

small hole

71a, 71b, 72a, 72b, 73a, 73b has a rectangular, triangular, polygonal, or elliptical cross-sectional shape, as shown in FIGS. 6(a) to 7(c). square, triangular, polygonal, or elliptical with straight portions, the

small holes

71a, 71b, 72a, 72b, 73a, 73b and the

small holes

71a, 71b, 72a, 72b, 73a, 73b and It is possible to stably secure the minimum distance of the intervals between the , and to suppress variations in magnetic resistance due to processing errors.
Further, by arranging the

small holes

73a and 73b so as to be inclined with respect to the virtual center line A of the tooth base, the magnetic flux flow around the

small holes

73a and 73b can be changed.

Two

small holes

70a and 70b are arranged at different distances from the facing surface 35 in the stator tooth tip portion 32b of the stator core 30 shown in FIG. 7(d).
The stator tooth tip portion 32b of the stator core 30 shown in FIG. 7(e) is provided with three

small holes

70a, 70b, and 70c. They are arranged at different distances from 35.

By arranging the

small holes

70a, 70b, and 70c as shown in FIGS. Therefore, it is possible to adjust the flow of the magnetic flux, and to reduce the fluctuation of the teeth direction (radial direction) force while maintaining the same torque as when the

small holes

70a, 70b, and 70c are not provided.

Two

small holes

70a and 70d are provided in the stator tooth tip portion 32b of the stator core 30 shown in FIG. 7(f), and the sizes of the two

small holes

70a and 70d are made different. Thus, the sizes of the

small holes

70a and 70d may be different. 6A to 7E, the sizes of the

small holes

70a, 70b, 70c, 70d, 71a, 71b, 72a, 72b, 73a, and 73b may be different.

By using the permanent magnet synchronous motor 3 according to this embodiment, the compressor 10 with low noise due to low vibration and high efficiency can be realized without lowering the torque.
In addition, equipment using the compressor 10 according to this embodiment can realize low noise due to low vibration and high efficiency.

FIG. 8 is a block diagram showing the essential parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention.
FIG. 8A shows the arrangement of the compression mechanism 2 that compresses the refrigerant gas and the permanent magnet synchronous motor 3 that drives the compression mechanism 2 . The compression mechanism section 2 and the permanent magnet synchronous motor 3 are connected by a shaft 8 . The compression mechanism portion 2 is a rotary compression mechanism.
The permanent magnet synchronous motor 3 has a rotor 3a and a stator 3b. The stator 3b is constructed by laminating a plurality of stator cores 30 in the axial direction of the rotating shaft 8 of the rotor 3a.
The stator core 30 has an annular stator yoke 31 and a plurality of stator teeth 32, as described with reference to FIG. A winding 50 is arranged in the .
In this embodiment, a stator core 30a having

small holes

70a, 70b and 70c and a stator core 30b having no

small holes

70a, 70b and 70c are used.

FIG. 8(b) shows a stator core 30a with

small holes

70a, 70b, 70c, and FIG. 8(c) shows a stator core 30b without

small holes

70a, 70b, 70c. The stator core 30a shown in FIG. 8(b) is the stator core 30 already described with reference to FIG. 6(a).
Then, as shown in FIG. 8A, the stator core 30b without the

small holes

70a, 70b, and 70c is stacked on the side of the compression mechanism 2, and the small holes 70a are formed on the side away from the compression mechanism 2. , 70b, 70c are stacked.
Fluctuations in the teeth direction (radial direction) force of the stator core 30a are smaller than the teeth direction (radial direction) force of the stator core 30b. Therefore, particularly in a rotary compressor in which the rotor 3a is cantilever-supported by the compression mechanism 2, the stator core 30a with small variation in force in the teeth direction (radial direction) is arranged at a position far from the compression mechanism 2. By doing so, the deflection of the shaft 8 can be reduced.
When the rotor 3a is supported by the compression mechanism 2 in a cantilevered manner, the deflection of the shaft 8 tends to cause eccentricity of the air gap. Sliding loss increases. By arranging the stator core 30a at a position where the air gap is narrowed as in the present embodiment, the magnetic attraction force acting thereon in the teeth direction (radial direction) can be reduced. Due to the reduced deflection, it is possible to provide a highly reliable compressor 10 with low noise due to low vibration.

Although FIG. 8A shows the compressor 10 in which the compression mechanism 2 is arranged below the permanent magnet synchronous motor 3, the compressor in which the compression mechanism 2 is arranged above the permanent magnet synchronous motor 3 is shown. , or a compressor in which the compression mechanism 2 and the permanent magnet synchronous motor 3 are arranged in the horizontal direction.
Moreover, FIG. 8(b) shows the stator core 30 shown in FIG. 6(a), but the stator core 30 shown in FIGS. The same is true when using the stator core 30 shown in (f).

FIG. 9 is a graph showing tooth direction (radial direction) force and torque according to the embodiment shown in FIG.
FIG. 9(a) shows the relationship between the tooth direction (radial direction) force acting on one stator tooth tip portion 32b and the rotation angle of the rotor 3a. Comparative Example 1 uses only the stator core 30a, and Comparative Example 2 uses only the stator core 30b without small holes.
As the rotor 3a rotates, the stator tooth tip portions 32b receive a tooth direction (radial direction) force of a periodic component corresponding to the number of rotor magnetic poles. This embodiment is a 6-pole motor, and the tooth direction (radial direction) force acting on one stator tooth tip portion is a tooth direction (radial direction) force having one periodic component at a rotation angle of 60°.
In this embodiment, the motor is a three-phase motor, and the fluctuation phase of the force acting on the stator tooth tip portion 32b is 120° in electrical angle and 40° in rotation angle in the tooth direction (radial direction). .
A large fluctuation range of the force in the direction of the teeth (radial direction) causes the vibration of the stator teeth 32 to be large and the vibration of the motor to be large. Vibration of typical rotary compressors and scroll compressors is a major factor.
A low-vibration motor and compressor 10 can be realized by reducing the variation width of the teeth direction (radial direction) force.
The tooth direction (radial direction) force does not uniformly act on the stator tooth tip portions 32b, and the location where the force acts locally changes as the rotor 3a rotates.
According to this embodiment, as shown in FIG. 9(a), it is possible to effectively reduce the tooth direction (radial direction) force acting locally as the rotor 3a rotates. The fluctuation force ratio in the teeth direction (radial direction) is 91% in Comparative Example 1 with only the stator core 30a compared to Comparative Example 2 with only the stator core 30b, which is a conventional example. is 95%.

On the other hand, as shown in FIG. 9B, Comparative Example 1 in which the stator core 30 is composed only of the stator core 30a, Comparative Example 2 in which the stator core 30 is composed of only the stator core 30b, and the present embodiment Comparing the torques of (the stator core 30a and the stator core 30b), it can be seen that the maximum and minimum values of the torque in this embodiment are significantly reduced, and the torque pulsation is halved. Reducing torque pulsation reduces vibration in the torsional direction and also contributes to improved controllability because torque fluctuations relative to the command current are small.

FIG. 10 is a block diagram showing the essential parts of a compressor using a permanent magnet synchronous motor according to still another embodiment of the present invention.
FIG. 10( a ) shows the arrangement of the compression mechanism 2 that compresses the refrigerant gas and the permanent magnet synchronous motor 3 that drives the compression mechanism 2 . The compression mechanism section 2 and the permanent magnet synchronous motor 3 are connected by a shaft 8 . Compression mechanism 2 is the scroll compression mechanism shown in FIG.
The permanent magnet synchronous motor 3 has a rotor 3a and a stator 3b. The stator 3b is constructed by laminating a plurality of stator cores 30 in the axial direction of the rotating shaft 8 of the rotor 3a.
The stator core 30 has an annular stator yoke 31 and a plurality of stator teeth 32, as described with reference to FIG. A winding 50 is arranged in the .
In this embodiment, a stator core 30a having

small holes

70a, 70b and 70c and a stator core 30b having no

small holes

70a, 70b and 70c are used.
FIG. 10(b) shows a stator core 30a with

small holes

70a, 70b and 70c, and FIG. 10(c) shows a stator core 30b without

small holes

70a, 70b and 70c. The stator core 30a shown in FIG. 10(b) is the stator core 30 already described with reference to FIG. 6(a).

Then, as shown in FIG. 10A, stator cores 30b without

small holes

70a, 70b, and 70c are stacked on the side of the compression mechanism 2 and the side away from the compression mechanism 2, and these are fixed. A stator core 30a forming

small holes

70a, 70b, 70c is laminated between the child cores 30b.
Fluctuations in the teeth direction (radial direction) force of the stator core 30a are smaller than the teeth direction (radial direction) force of the stator core 30b. Therefore, particularly in a scroll compressor in which the rotor 3a is both supported by the compression mechanism 2 and the bearing 7b, the stator core 30a having a small force fluctuation in the tooth direction (radial direction) is placed at a position far from the compression mechanism 2. By arranging them, the deflection of the shaft 8 can be reduced.
When the rotor 3a is supported on both sides by the compression mechanism 2 and the bearing 7b, the stator core 30a is placed near the center between the shaft supports where the shaft is likely to bend. can provide a highly reliable compressor 10 with low noise due to low vibration. When the compression mechanism 2 side uses a high-rigidity shaft 8 having a larger diameter and longer axial length than the bearing 7b side, the stator core 30b is arranged on the compression mechanism 2 side, and is far from the compression mechanism 2 side. The stator core 30a may be arranged at the position.

FIG. 10A shows a compressor in which the compression mechanism 2 is arranged above the permanent magnet synchronous motor 3, but the compressor in which the compression mechanism 2 is arranged below the permanent magnet synchronous motor 3 The same applies to the compressor 10 that uses the compression mechanism 2 and the permanent magnet synchronous motor 3 arranged in the horizontal direction.
Moreover, FIG. 10(b) shows the stator core 30 shown in FIG. 6(a), but the stator core 30 shown in FIGS. The same is true when using the stator core 30 shown in (f).
The so-called split cores, which are divided in the circumferential direction and then the stator is arranged in the circumferential direction and united after high-density winding is performed, or the high-density winding is performed in the state where a part of the stator yoke is joined. The small-hole-arranged core shown in the present embodiment may be used in a motor using a stator in which the yoke portion is deformed or moved so as to be in close contact with the stator in the circumferential direction.
A split core stator or a stator in which a part of a stator yoke is joined has lower rigidity than a general stator integral in the circumferential direction. In addition, in a T-shaped stator in which the angle between the teeth and the yoke is a right angle due to the high-density winding, the rigidity is low even if the width dimension of the yoke portion between the teeth becomes small. The permanent magnet synchronous motor of the present invention can reduce fluctuations in radial force even with respect to the split cores, and can achieve low noise due to low vibration and high efficiency.

The permanent magnet synchronous motor of the present invention is suitable for scroll compressors and rotary compressors, but can also be used for reciprocating compressors and other compressors.

REFERENCE SIGNS LIST 1 airtight container 2 compression mechanism 2a fixed scroll 2b orbiting scroll 3 permanent magnet synchronous motor 3a rotor 3b stator 4 oil reservoir 5 suction pipe 6 discharge pipe 7a main bearing member 7b bearing 8 shaft (rotation shaft of rotor)
8a eccentric shaft portion 9 rotation restraint mechanism 10 compressor 11

permanent magnet

30, 30a, 30b stator core 31 stator yoke 32 stator tooth 32a stator tooth base 32b stator tooth tip 35 opposing surface 40 slot 50 winding 61 Condenser 62 Decompression device 63 Evaporator 70

Small hole group

70a, 70b, 70c, 70d, 71a, 71b, 72a, 72b, 73a, 73b Small hole 70x Imaginary center t Width dimension A Teeth base virtual centerline

Claims

a rotor rotatably arranged around a rotation axis;
Having the rotor and a stator arranged via an air gap,
The stator is
an annular stator yoke centered on the rotation axis;
a plurality of stator teeth extending from the stator yoke toward the rotor;
slots formed between the stator teeth;
A winding is arranged in the slot,
The stator teeth are
a stator tooth base on which the winding is wound;
a stator tooth tip portion forming a surface facing the rotor at the tip of the stator tooth base portion,
A permanent magnet synchronous motor, characterized in that at least two small holes are arranged side by side in a direction along the facing surface in the distal end portions of the stator teeth.
The circumferential width dimension center of the stator tooth base is defined as a tooth base imaginary center line,
2. A plurality of said small holes are arranged so that a virtual center of a group of small holes made up of said plurality of small holes is located in a counter-rotating direction of said rotor with respect to a virtual center line of said tooth base. A permanent magnet synchronous motor as described.
3. The permanent magnet synchronous motor according to claim 1, wherein the number of said small holes is three or more.
4. The permanent magnet synchronous motor according to any one of claims 1 to 3, wherein the cross-sectional shape of at least one of the small holes is quadrangular, triangular, polygonal, or elliptical.
5. The permanent magnet synchronous motor according to any one of claims 1 to 4, wherein the small holes are arranged at different distances from the facing surface.
6. The permanent magnet synchronous motor according to any one of claims 1 to 5, wherein the respective small holes are arranged side by side so as to be inclined with respect to the imaginary center line of the tooth base.
The stator is configured by stacking a plurality of stator cores in the axial direction of the rotating shaft,
forming the small holes in a part of the stator core,
7. The permanent magnet synchronous motor according to claim 1, wherein the small holes are not formed in the other stator cores.
Using the permanent magnet synchronous motor according to claim 7,
connecting the permanent magnet synchronous motor and the compression mechanism with a shaft;
disposing the stator core without the small holes on the side of the compression mechanism,
A compressor according to claim 1, wherein the stator core forming the small holes is arranged on a side away from the compression mechanism.
Using the permanent magnet synchronous motor according to any one of claims 1 to 7,
connecting the permanent magnet synchronous motor and the compression mechanism with a shaft;
A compressor, wherein the compression mechanism section compresses a refrigerant.
10. A device comprising a compressor, a condenser, a decompression device, and an evaporator according to claim 8 or 9, which are annularly connected by piping.