Permanent magnet synchronous motor, compressor and device

Abstract

The permanent magnet synchronous motor 3 of the present application is configured such that the stator 3b has a ring-shaped stator yoke 31 centered on the rotation axis 8; a plurality of stator teeth 32 extending from the stator yoke 31 toward the rotor 3a; and slots 40 formed between the stator teeth 32, in which windings 50 are disposed, the stator teeth 32 having stator tooth bases 32a on which the windings 50 are wound and stator tooth tip portions 32b located at the front ends of the stator tooth bases 32a and forming facing surfaces 35 opposite the rotor 3a, by arranging at least two small holes 70a, 70b in the stator tooth tip portions 32b in a direction along the facing surfaces 35, variation in tooth direction (radial direction) force can be reduced, and low noise and high efficiency resulting from low vibration can be achieved.

Description

Technical Field

[0001] This invention relates to a permanent magnet synchronous motor, a compressor using the permanent magnet synchronous motor, and equipment using the compressor. Background Technology

[0002] Patent document 1 discloses a rotary motor that can simultaneously suppress the decrease in the circumferential torque that the rotary motor should generate and reduce the radial electromagnetic excitation force generated by the rotary motor.

[0003] In Patent Document 1, the reduction in circumferential torque is suppressed by providing an axial connecting hole near the air gap in the tooth.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-96022 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] Findings: The electromagnetic excitation force acting on the stator teeth varies depending on the rotor's rotational position and the current flowing through it. The radial force is the largest when the electromagnetic excitation force is enhanced from the center of the teeth on the side facing the opposite direction of rotation. However, it is important to adjust the flow of magnetic flux without causing a decrease in torque.

[0009] The purpose of this invention is to provide a permanent magnet synchronous motor that can reduce the variation of radial force, achieve low noise and high efficiency based on low vibration, and to provide compressors using the permanent magnet synchronous motor for air conditioners, dehumidifiers, heat pump water heaters, cold storage (household cold storage, commercial cold storage), ice makers, display cases, heat pump washer-dryers, vending machines, etc., and equipment using the compressor.

[0010] Technical solutions for solving technical problems

[0011] The permanent magnet synchronous motor of the present invention according to claim 1 is characterized in that it has: a rotor configured to rotate around a rotation axis; and a stator disposed with respect to the rotor via an air gap, the stator having: an annular stator yoke centered on the rotation axis; a plurality of stator teeth extending from the stator yoke toward the rotor; and slots formed between the stator teeth, in which windings are disposed, the stator teeth having: stator tooth bases for windings to be wound thereon; and stator tooth front ends located at the front end of the stator tooth bases, forming opposing surfaces opposite to the rotor, wherein at least two small holes are arranged in a direction along the opposing surfaces at the stator tooth front ends.

[0012] The present invention as described in claim 2 is characterized in that, in the permanent magnet synchronous motor as described in claim 1, the center of the circumferential width dimension of the stator tooth base is taken as the imaginary center line of the tooth base, and the plurality of holes are configured such that the imaginary center of the hole group formed by the plurality of holes is located in the opposite direction to the rotation direction of the rotor compared to the imaginary center line of the tooth base.

[0013] The present invention as described in claim 3 is characterized in that, in the permanent magnet synchronous motor as described in claim 1 or claim 2, there are three or more small holes.

[0014] The present invention as described in claim 4 is characterized in that, in the permanent magnet synchronous motor described in any one of claims 1 to 3, at least one of the small holes has a cross-sectional shape of quadrilateral, triangle, polygon or ellipse.

[0015] The invention as described in claim 5 is characterized in that, in the permanent magnet synchronous motor according to any one of claims 1 to 4, each of the small holes is configured at a different distance from the opposite surface.

[0016] The invention as described in claim 6 is characterized in that, in the permanent magnet synchronous motor according to any one of claims 1 to 5, each of the small holes is arranged in an inclined manner relative to the imaginary center line of the tooth base.

[0017] The invention as described in claim 7 is characterized in that, in the permanent magnet synchronous motor according to any one of claims 1 to 6, the stator is formed by stacking a plurality of stator cores axially on the rotating shaft, wherein the small holes are formed in a portion of the stator cores and not in the other stator cores.

[0018] The compressor of the present invention according to claim 8 is characterized in that it uses the permanent magnet synchronous motor according to claim 7, wherein the permanent magnet synchronous motor and the compression mechanism are connected by a shaft, a stator core without the small hole is arranged on the side of the compression mechanism, and a stator core with the small hole is arranged on the side away from the compression mechanism.

[0019] The compressor of the present invention according to claim 9 is characterized in that it uses a permanent magnet synchronous motor according to any one of claims 1 to 7, wherein the permanent magnet synchronous motor and the compression mechanism are connected by a shaft, and the refrigerant can be compressed by the compression mechanism.

[0020] The device of the present invention as described in claim 10 is characterized in that the compressor, condenser, pressure reducing device and evaporator as described in claim 8 or claim 9 are connected in a ring by piping.

[0021] Invention Effects

[0022] According to the present invention, the flow of magnetic flux can be adjusted, the torque can be maintained at the same level as when no orifice is provided, and the variation of radial force can be reduced, thereby achieving low noise and high efficiency due to low vibration. Attached Figure Description

[0023] Figure 1 This is a longitudinal cross-sectional view showing the structure of a compressor using a permanent magnet synchronous motor according to an embodiment of the present invention.

[0024] Figure 2 This is a structural diagram of the permanent magnet synchronous motor in this embodiment.

[0025] Figure 3 This is a structural diagram showing the main parts of the stator core of the permanent magnet synchronous motor in this embodiment.

[0026] Figure 4 This is a graph (line diagram) showing the force and torque in the tooth direction (radial direction) of this embodiment.

[0027] Figure 5 It is a graph showing the relationship between the variation of force and torque in the tooth direction (radial direction) relative to the configuration angle of the pinhole.

[0028] Figure 6 This is a structural diagram of the main parts of the stator core of a permanent magnet synchronous motor according to another embodiment of the present invention.

[0029] Figure 7 This is a structural diagram of the main parts of the stator core of a permanent magnet synchronous motor according to another embodiment of the present invention.

[0030] Figure 8 This is a structural diagram showing the main parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention.

[0031] Figure 9 It means Figure 8 A graph showing the tooth-direction (radial direction) force and torque of the embodiment shown.

[0032] Figure 10 This is a structural diagram showing the main parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention. Detailed Implementation

[0033] In the permanent magnet synchronous motor according to the first embodiment of the present invention, at least two small holes are arranged in a direction along opposite surfaces at the front end of the stator teeth. According to this embodiment, the flow of magnetic flux can be adjusted, the same torque as when the small holes are not provided can be maintained, and the variation of the force in the tooth direction (radial direction) can be reduced, thereby achieving low noise and high efficiency due to low vibration.

[0034] The second embodiment of the present invention is as follows: In the permanent magnet synchronous motor of the first embodiment, the center of the circumferential width dimension of the stator tooth base is taken as the imaginary center line of the tooth base. Multiple small holes are arranged such that the imaginary center of the group of small holes is located in the opposite direction to the rotor's rotation direction compared to the imaginary center line of the tooth base. According to this embodiment, the small hole group can be configured at an angle where the force in the tooth direction (radial direction) locally increases, thereby simultaneously reducing the variation of the force in the tooth direction (radial direction) and suppressing torque decrease.

[0035] The third embodiment of the present invention is that in the permanent magnet synchronous motor of the first or second embodiment, there are three or more pinholes. According to this embodiment, the flow of magnetic flux is easily adjusted, the torque is maintained at the same level as when no pinholes are provided, and the variation of the force in the tooth direction (radial direction) is reduced, thereby achieving low noise and high efficiency due to low vibration.

[0036] The fourth embodiment of the present invention is as follows: In the permanent magnet synchronous motor of any of the first to third embodiments, at least one of the small holes has a cross-sectional shape of quadrilateral, triangle, polygon, or ellipse. According to this embodiment, since the quadrilateral, triangle, polygon, or ellipse includes a straight portion, the minimum distance between the small holes can be reliably ensured, and the deviation of magnetic reluctance caused by processing errors can be suppressed.

[0037] The fifth embodiment of the present invention is as follows: In the permanent magnet synchronous motor of any of the first to fourth embodiments, each small hole is arranged such that its distance from the opposite surface is different. According to this embodiment, it is possible to make an arrangement corresponding to the magnetic flux acting on the stator and the stator tooth direction (radial direction) force that accompanies the rotation of the rotor, to adjust the flow of magnetic flux, to maintain the same torque as in the case where the small holes are not provided, and to reduce the variation of the tooth direction (radial direction) force.

[0038] The sixth embodiment of the present invention involves arranging the individual small holes in a manner that is inclined relative to the imaginary centerline of the tooth base in any of the first to fifth embodiments of the permanent magnet synchronous motor. According to this embodiment, the flow of magnetic flux around the small holes can be altered.

[0039] The seventh embodiment of the present invention is as follows: In the permanent magnet synchronous motor of any of the first to sixth embodiments, the stator is constructed by stacking multiple stator cores axially along the rotation axis, with small holes formed in some of the stator cores and no small holes formed in the other stator cores. According to this embodiment, the torque pulsation phase shifts between the stator cores without small holes and the stator cores with small holes; therefore, by stacking these stator cores, torque pulsation can be reduced.

[0040] The compressor of the eighth embodiment of the present invention uses the permanent magnet synchronous motor of the seventh embodiment. The permanent magnet synchronous motor and the compression mechanism are connected by a shaft. A stator core without holes is arranged on the side of the compression mechanism, and a stator core with holes is arranged on the side away from the compression mechanism. According to this embodiment, by arranging a stator core with small variation in tooth direction (radial direction) force on the side away from the compression mechanism, the support rigidity of the rotor is increased.

[0041] The compressor of the ninth embodiment of the present invention uses a permanent magnet synchronous motor from any of the first to seventh embodiments. The permanent magnet synchronous motor and the compression mechanism are connected by a shaft, and the refrigerant can be compressed using the compression mechanism. According to this embodiment, a compressor with low vibration, low noise, and high efficiency can be realized without reducing torque.

[0042] In the tenth embodiment of the present invention, the compressor, condenser, pressure reducing device, and evaporator of the eighth or ninth embodiment are connected in a ring by piping. According to this embodiment, a low-noise and high-efficiency device based on low vibration can be realized without reducing torque.

[0043] Example

[0044] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0045] Figure 1 This is a longitudinal cross-sectional view showing the structure of the compressor using the permanent magnet synchronous motor of this embodiment.

[0046] In this embodiment, the compressor 10 includes a compression mechanism 2 for compressing refrigerant gas and a permanent magnet synchronous motor 3 for driving the compression mechanism 2 within a sealed container 1.

[0047] The sealed container 1 is divided into two internal spaces by a compression mechanism 2. A permanent magnet synchronous motor 3 is installed in the other internal space.

[0048] In addition, another space within the container is divided into a compression mechanism side space and an oil storage side space by a permanent magnet synchronous motor 3. An oil storage section 4 is arranged in the oil storage side space.

[0049] The suction pipe 5 and the discharge pipe 6 are fixed to the sealed container 1 by welding. The suction pipe 5 and the discharge pipe 6 communicate with the outside of the sealed container 1 and are connected to the components constituting the refrigeration cycle. The suction pipe 5 introduces refrigerant gas from the outside of the sealed container 1, and the discharge pipe 6 discharges refrigerant gas from an internal space of the container to the outside of the sealed container 1.

[0050] The main bearing assembly 7a is fixed inside the sealed container 1 by welding, heat fitting, etc., and provides shaft support for the shaft 8 (the rotating shaft of the rotor 3a). One end of the shaft 8 is supported by the main bearing assembly 7a, and the other end is supported by the bearing 7b. A fixed scroll member 2a is bolted to the main bearing assembly 7a. The rotating scroll member 2b, which meshes with the fixed scroll member 2a, is sandwiched between the main bearing assembly 7a and the fixed scroll member 2a. The fixed scroll member 2a and the rotating scroll member 2b constitute the scroll-type compression mechanism 2.

[0051] A rotation limiting mechanism 9, composed of an Oldham ring or similar component, is provided between the gyratory scroll member 2b and the main bearing component 7a. This mechanism prevents the gyratory scroll member 2b from rotating and guides it in circular motion. The gyratory scroll member 2b is eccentrically driven by an eccentric shaft portion 8a located at the upper end of the shaft 8. This eccentric drive causes the compression chamber formed between the fixed scroll member 2a and the gyratory scroll member 2b to move from the outer periphery of the compression mechanism portion 2 toward the center, reducing its volume and thus compressing the scroll.

[0052] The permanent magnet synchronous motor 3 has: a rotor 3a configured to rotate around a rotating shaft 8; and a stator 3b configured with an air gap between it and the rotor 3a.

[0053] The refrigerant is drawn into the compression unit 2 through the suction pipe 5 and compressed by the compression unit 2. Afterward, the refrigerant is discharged through the discharge pipe 6.

[0054] In this embodiment, the compressor 10, condenser 61, pressure reducing device 62, and evaporator 63 are connected in a ring by piping. The refrigerant discharged from the discharge pipe 6 is condensed in the condenser 61, the pressure reducing device 62 reduces the pressure on the condensed refrigerant, and the pressure-reduced refrigerant evaporates in the evaporator 63.

[0055] The refrigerant evaporated by evaporator 63 returns to compressor 10 through suction pipe 5.

[0056] Figure 2 This is a structural diagram of the permanent magnet synchronous motor in this embodiment. Figure 2 (a) is installed in Figure 1 The diagram shown is a cross-sectional view of the compressor in its current state. Figure 2 (b) indicates from Figure 2 (a) Cross-sectional view of the shaft and rotor after removal. Figure 2 (c) indicates from Figure 2 (a) Cross-sectional view of the state after the sealed container and windings have been removed.

[0057] The rotor 3a is fixed to the shaft 8, and the stator 3b is fixed to the sealed container 1. In the compressor 10 of this embodiment, the rotation shaft of the rotor 3a is the shaft 8.

[0058] The rotor 3a is made of a magnetic body, and multiple slits are provided inside the rotor 3a, in which permanent magnets 11 are respectively arranged.

[0059] The stator 3b is constructed by stacking multiple stator cores 30 along the axial direction of the rotation axis 8 of the rotor 3a. Each stator core 30 has: an annular stator yoke 31 centered on the rotation axis 8 of the rotor 3a; multiple stator teeth 32 extending from the stator yoke 31 toward the rotor 3a; and slots 40 formed between the stator teeth 32. Windings 50 are arranged in the slots 40.

[0060] Figure 3 This is a structural diagram showing the main parts of the stator core of the permanent magnet synchronous motor in this embodiment.

[0061] The stator teeth 32 of the stator core 30 in this embodiment have: a winding 50 wound around the stator core 30 with an insulating material (not shown) in between (see reference). Figure 2 The stator tooth base 32a; and the stator tooth base 32a has a tooth base at the front end that forms with the rotor 3a (see reference). Figure 2 The stator tooth front end 32b of the opposite face 35.

[0062] The stator tooth front end 32b is formed by extending to both sides compared with the circumferential width dimension t (width dimension portion) of the stator tooth base 32a.

[0063] At the front end 32b of the stator tooth, at least two small holes 70a and 70b are arranged along the direction of the opposite surface 35. Here, the small holes 70a and 70b are used to increase magnetic resistance. As long as they are non-magnetic, they are effective. They can be gaps or resin-embedded holes.

[0064] By configuring these small holes 70a and 70b, the flow of magnetic flux can be adjusted, the same torque as when no small holes are set can be maintained, and the variation of force in the tooth direction (radial direction) can be reduced, thus achieving low noise and high efficiency based on low vibration.

[0065] When the center of the circumferential width dimension t of the stator tooth base 32a is taken as the imaginary center line A of the tooth base, the multiple holes 70a and 70b are arranged in such a way that the imaginary (virtual) center 70x of the hole group 70 composed of multiple holes 70a and 70b is in the opposite direction of the rotation direction of the rotor 3a compared with the imaginary center line A of the tooth base.

[0066] By configuring multiple small holes 70a and 70b in this way, especially by configuring the small hole group 70 at an angle that locally increases the force in the tooth direction (radial direction), it is possible to both reduce the variation of the force in the tooth direction (radial direction) and suppress the decrease in torque.

[0067] For example, in a six-pole, nine-tooth permanent magnet synchronous motor 3, it is preferable to arrange multiple small holes 70a and 70b such that the imaginary center 70x is located at a position that is offset by about 2° to 3° in the opposite direction of the rotation direction of the rotor 3a compared to the imaginary center line A of the tooth base.

[0068] Specifically, when the diameter of the small hole 70a is 70at and the diameter of the small hole 70b is 70bt, it is preferable that the diameters 70at and 70bt are 1mm or more, the diameter 70at + diameter 70bt ≤ width dimension t / 2, the distance between the small holes 70a and 70b is 0.5mm or more, the distance between the small hole 70a and the opposite surface 35 is 0.5mm or more, and the distance between the small hole 70b and the opposite surface 35 is 0.5mm or more.

[0069] Figure 4 This is a graph showing the force and torque in the tooth direction (radial direction) of this embodiment.

[0070] Figure 4 (a) shows the relationship between the tooth-direction (radial direction) force acting on the front end 32b of one stator tooth and the rotation angle (rotation angle) of the rotor 3a. No small holes are provided in the existing example.

[0071] The front end 32b of the stator tooth is subjected to a tooth-direction (radial direction) force with a periodic component corresponding to the number of rotor poles due to the rotation of the rotor 3a. In this embodiment, which is a six-pole motor, the tooth-direction (radial direction) force acting on the front end of one stator tooth is a tooth-direction (radial direction) force with a periodic component at a rotation angle of 60°.

[0072] Furthermore, in this embodiment, which is a three-phase motor, the change in the force acting on the front end 32b of the stator teeth results in a phase shift of electrical angle 120° and rotation angle 40° regarding the change in the force in the tooth direction (radial direction).

[0073] When the force in the tooth direction (radial direction) changes greatly, the vibration of the stator teeth 32 is large and the vibration of the motor also increases. This is the main reason for the large vibration of ordinary rotary compressors and scroll compressors, where the outer periphery of the stator 3b is in contact with and fixed to the inner wall of the compressor 10.

[0074] By reducing the amplitude of force variation in the tooth direction (radial direction), low-vibration motors and compressors 10 can be achieved.

[0075] The force in the tooth direction (radial direction) does not act uniformly on the front end 32b of the stator teeth; the localized area of ​​force changes as the rotor 3a rotates.

[0076] like Figure 4As shown in (a), according to this embodiment, the tooth-direction (radial-direction) force acting locally accompanying the rotation of rotor 3a can be effectively reduced. The variable force ratio in the tooth-direction (radial-direction) is 86% compared to the conventional example.

[0077] On the other hand, such as Figure 4 As shown in (b), comparing the torque of the existing example with the torque of this embodiment, it can be seen that the maximum and minimum values ​​of the torque of this embodiment are increased, but the average torque is the same as that of the existing motor.

[0078] Figure 5 This is a graph showing the relationship between the variation in force and torque in the tooth direction (radial direction) relative to the orifice configuration angle. Figure 5 In this embodiment, the configuration of the two small holes 70a and 70b shown has been changed. Let the imaginary center line A of the stator tooth base be 0° as the configuration angle of the small holes, use a negative angle to represent the rotation direction side, and use a positive angle to represent the opposite side of the rotation direction.

[0079] like Figure 5 As shown, changing the configuration angle of the pinholes 70a and 70b alters the amplitude of the force variation and the torque in the tooth direction (radial direction). Here, reducing the amplitude of the force variation in the tooth direction (radial direction) is effective in reducing vibration.

[0080] exist Figure 5 When two small holes 70a and 70b are configured in the A-range shown (approximately -5° to 9°), the variation in force in the tooth direction (radial direction) is reduced. In particular, when small holes 70a and 70b are configured at approximately 3° in the opposite direction of rotation, the reduction in the variation in force in the tooth direction (radial direction) is significant.

[0081] On the other hand, the torque is the same in the range of -3° to 7° as it is without the orifice.

[0082] Therefore, by positioning the small holes 70a and 70b at a position approximately 3° away from the imaginary center line A of the tooth base in the opposite direction of rotation, both low vibration and high torque can be achieved simultaneously.

[0083] Figure 6 and Figure 7 These are structural diagrams showing the main parts of the stator core of a permanent magnet synchronous motor in other embodiments. The structure other than the small holes is the same as in the embodiments described above, and therefore descriptions are omitted.

[0084] exist Figure 6 (a) The stator core 30 shown has three small holes 70a, 70b and 70c at the front end 32b of the stator teeth.

[0085] It is also possible to have three or more orifices 70a, 70b, and 70c. By setting three or more orifices 70a, 70b, and 70c, it is easy to adjust the flow of magnetic flux, maintain the same torque as when orifices 70a, 70b, and 70c are not set, and reduce the variation of force in the tooth direction (radial direction). This results in low noise and high efficiency due to low vibration.

[0086] exist Figure 6 (b) The stator core 30 shown has small holes 71a and 71b with a quadrilateral cross-sectional shape at the front end 32b of the stator teeth. Figure 6 (a) shows the case where two small holes 71a and 71b are set, but more than three holes can also be set.

[0087] exist Figure 6 (c) The stator core 30 shown has small holes 72a and 72b at the front end 32b of the stator teeth, with the straight portion of the triangle located on one side of the opposite surface 35. Figure 6 (c) shows the case where two small holes 72a and 72b are set, but more than three holes can also be set.

[0088] exist Figure 6 (d) The stator core 30 shown has small holes 72a and 72b at the front end 32b of the stator teeth, with the vertices of the triangles located on one side of the opposite surface 35. Figure 6 (d) shows the case where two holes 72a and 72b are set, but more than three holes can also be set.

[0089] exist Figure 6 (e) The stator core 30 shown has stator teeth front end 32b with triangular cross-section holes 72a and 72b. Hole 72a positions the straight portion of the triangle on one side of the opposite surface 35, and hole 72b positions the vertex portion of the triangle on one side of the opposite surface 35. Figure 6 (e) shows the case where two holes 72a and 72b are set, but more than three holes can also be set.

[0090] Among them, Figure 6 (b) shows small holes 71a and 71b with quadrilateral cross-sectional shapes. Figure 6 (c) to Figure 6 (e) shows small holes 72a and 72b with triangular cross-sectional shapes, but the cross-sectional shapes can also be other polygons.

[0091] exist Figure 7 (a) The stator core 30 shown has small holes 73a and 73b with an elliptical cross-sectional shape at the front end 32b of the stator teeth, such that the long side of the ellipse is along the tooth direction (radial direction). Figure 7(a) shows the case where two small holes 73a and 73b are set, but more than three holes can also be set.

[0092] exist Figure 7 (b) The stator core 30 shown has small holes 73a and 73b at the front end 32b of the stator teeth, with the long side of the ellipse along the direction of rotation. Figure 7 (b) shows the case where two small holes 73a and 73b are set, but more than three holes can also be set.

[0093] exist Figure 7 (c) The stator core 30 shown has small holes 73a and 73b with an elliptical cross-sectional shape at the front end 32b of the stator teeth, such that the long side of the ellipse is inclined relative to the imaginary center line A of the tooth base. Figure 7 (c) shows the case where two small holes 73a and 73b are set, but more than three holes can also be set.

[0094] like Figure 6 (a) to Figure 7 As shown in (c), the cross-sectional shape of at least one hole 71a, 71b, 72a, 72b, 73a, 73b can be a quadrilateral, a triangle, a polygon, or an ellipse. Since the quadrilateral, triangle, polygon, or ellipse includes a straight section, the minimum distance between the holes 71a, 71b, 72a, 72b, 73a, 73b and the holes 71a, 71b, 72a, 72b, 73a, 73b can be stably ensured, and the deviation of magnetic reluctance caused by processing error can be suppressed.

[0095] Furthermore, by arranging the individual holes 73a and 73b in an inclined manner relative to the imaginary center line A of the tooth base, the magnetic flux flow around the holes 73a and 73b can be changed.

[0096] exist Figure 7 (d) shows that the stator core 30 has two small holes 70a and 70b at different distances from the opposite surface 35.

[0097] exist Figure 7 (e) The stator core 30 has three small holes 70a, 70b and 70c at the front end of the stator teeth. The small hole 70c is configured such that its distance from the opposite surface 35 is different from the distances of the two small holes 70a and 70b from the opposite surface 35.

[0098] Through like Figure 7 (d) and Figure 7(e) The small holes 70a, 70b, and 70c are configured in such a way that they correspond to the magnetic flux acting on the stator 3b and the force in the direction of the stator teeth 32 that accompanies the rotation of the rotor 3a. This configuration can adjust the flow of magnetic flux, maintain the same torque as when the small holes 70a, 70b, and 70c are not provided, and reduce the variation of the force in the tooth direction (radial direction).

[0099] exist Figure 7 (f) The stator core 30 shown has two small holes 70a and 70d at the front end 32b of the stator teeth, with the two holes 70a and 70d being of different sizes. The holes 70a and 70d can also be made of different sizes in this manner. Furthermore, in Figure 6 (a) to Figure 7 In (e), the sizes of the holes 70a, 70b, 70c, 70d, 71a, 71b, 72a, 72b, 73a, and 73b can also be different.

[0100] By using the permanent magnet synchronous motor 3 of this embodiment, a compressor 10 with low vibration, low noise, and high efficiency can be achieved without reducing torque.

[0101] Furthermore, the device using the compressor 10 of this embodiment can achieve low noise and high efficiency based on low vibration.

[0102] Figure 8 This is a structural diagram showing the main parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention.

[0103] exist Figure 8 (a) shows the configuration of the compression mechanism 2 for compressing refrigerant gas and the permanent magnet synchronous motor 3 that drives the compression mechanism 2. The compression mechanism 2 and the permanent magnet synchronous motor 3 are connected by a shaft 8. The compression mechanism 2 is a rotary compression mechanism.

[0104] The permanent magnet synchronous motor 3 has a rotor 3a and a stator 3b. The stator 3b is composed of multiple stator cores 30 stacked along the axial direction of the rotation axis 8 of the rotor 3a.

[0105] If used Figure 2 As described, the stator core 30 has an annular stator yoke 31 and a plurality of stator teeth 32, with slots 40 formed between the stator teeth 32, and windings 50 disposed in the slots 40.

[0106] In this embodiment, a stator core 30a with holes 70a, 70b, and 70c and a stator core 30b without holes 70a, 70b, and 70c are used as stator core 30.

[0107] Figure 8 (b) shows the stator core 30a with small holes 70a, 70b, and 70c formed thereon. Figure 8 (c) shows the stator core 30b without the small holes 70a, 70b, and 70c formed. Additionally, Figure 8 (b) The stator core 30a shown is used Figure 6 (a) describes the stator core 30.

[0108] like Figure 8 As shown in (a), a stator core 30b without small holes 70a, 70b, and 70c is stacked on the side of the compression mechanism section 2, while a stator core 30a with small holes 70a, 70b, and 70c is stacked on the side away from the compression mechanism section 2.

[0109] The variation of the tooth direction (radial direction) force of stator core 30a is smaller than that of stator core 30b. Therefore, especially in rotary compressors where the rotor 3a is cantilevered by the compression mechanism section 2, by arranging the stator core 30a, which has a smaller variation of tooth direction (radial direction) force, at a position farther from the compression mechanism section 2, the deflection of the shaft 8 can be reduced.

[0110] When the rotor 3a is cantilevered and supported by the compression mechanism 2, tilting caused by the deflection of the shaft 8 can easily lead to air gap eccentricity. The air gap becomes narrower the farther away from the compression mechanism 2, thus increasing sliding losses. By arranging the stator core 30a at the location where the air gap narrows, as in this embodiment, the magnetic attraction force in the tooth direction (radial direction) acting at this location can be reduced. Therefore, by reducing sliding losses and minimizing the deflection of the shaft 8, a compressor 10 with low vibration, low noise, and high reliability can be provided.

[0111] In addition, Figure 8 In (a), a compressor 10 with the compression mechanism 2 positioned below the permanent magnet synchronous motor 3 is shown. However, the same applies to compressors with the compression mechanism 2 positioned above the permanent magnet synchronous motor 3 or compressors with the compression mechanism 2 and the permanent magnet synchronous motor 3 arranged laterally.

[0112] In addition, Figure 8 (b) shows Figure 6 (a) shows the stator core 30, but using Figure 3 , Figure 6 (b) to Figure 6 (e) and Figure 7 (a) to Figure 7 The stator core 30 shown in (f) is the same.

[0113] Figure 9 It means Figure 8 A graph showing the tooth-direction (radial direction) force and torque of the embodiment shown.

[0114] Figure 9(a) shows the relationship between the tooth-direction (radial direction) force acting on the front end 32b of one stator tooth and the rotation angle of the rotor 3a. Comparative Example 1 uses only stator core 30a, and Comparative Example 2 uses only stator core 30b without the provided holes.

[0115] The stator tooth front end 32b is subjected to a tooth-direction (radial direction) force with a periodic component corresponding to the number of rotor poles by the rotation of the rotor 3a. In this embodiment, which is a six-pole motor, the tooth-direction (radial direction) force acting on the front end of one stator tooth is a tooth-direction (radial direction) force with a periodic component at a rotation angle of 60°.

[0116] Furthermore, in this embodiment, which is a three-phase motor, the phase of the force change in the tooth direction (radial direction) of the force acting on the front end 32b of the stator teeth is offset by an electrical angle of 120° and a rotation angle of 40°.

[0117] When the force in the tooth direction (radial direction) changes greatly, the vibration of the stator teeth 32 is also large, and the vibration of the motor also increases. This is the main reason for the large vibration of ordinary rotary compressors and scroll compressors, where the outer periphery of the stator 3b is fixed in contact with the outer wall of the compressor 10.

[0118] By reducing the variation amplitude of the force in the tooth direction (radial direction), low-vibration motors and compressors 10 can be achieved.

[0119] The force in the tooth direction (radial direction) is not uniformly applied to the front end 32b of the stator teeth; as the rotor 3a rotates, the location of the force changes.

[0120] like Figure 9 As shown in (a), according to this embodiment, the tooth direction (radial direction) force that acts locally accompanying the rotation of the rotor 3a can be effectively reduced. Compared with Comparative Example 2, which is a conventional example and only has a stator core 30b, the tooth direction (radial direction) variable force ratio in Comparative Example 1, which only has a stator core 30a, is 91%, and the average variable force ratio of the two is 95%.

[0121] On the other hand, such as Figure 9 As shown in (b), by comparing the torque of Comparative Example 1, in which the stator core 30 is composed only of stator core 30a, Comparative Example 2, in which the stator core 30 is composed only of stator core 30b, and this embodiment (stator core 30a and stator core 30b), it can be seen that the maximum and minimum torque values ​​of this embodiment are significantly reduced, and the torque ripple is halved. The reduction in torque ripple reduces vibration in the torsional direction, and the torque variation relative to the command current is small, thus also contributing to improved controllability.

[0122] Figure 10 This is a structural diagram showing the main parts of a compressor using a permanent magnet synchronous motor according to another embodiment of the present invention.

[0123] exist Figure 10 (a) shows the configuration of a compression mechanism 2 for compressing refrigerant gas and a permanent magnet synchronous motor 3 for driving the compression mechanism 2. The compression mechanism 2 and the permanent magnet synchronous motor 3 are connected by a shaft 8. The compression mechanism 2 is... Figure 1 The vortex compressor mechanism shown.

[0124] The permanent magnet synchronous motor 3 has a rotor 3a and a stator 3b. The stator 3b is composed of multiple stator cores 30 stacked along the axial direction of the rotation axis 8 of the rotor 3a.

[0125] If used Figure 2 As described, the stator core 30 has an annular stator yoke 31 and a plurality of stator teeth 32, with slots 40 formed between the stator teeth 32, and windings 50 disposed in the slots 40.

[0126] In this embodiment, a stator core 30a with holes 70a, 70b, and 70c and a stator core 30b without holes 70a, 70b, and 70c are used as stator core 30.

[0127] Figure 10 (b) shows the stator core 30a with small holes 70a, 70b, and 70c formed thereon. Figure 10 (c) shows the stator core 30b without the small holes 70a, 70b, and 70c formed. Additionally, Figure 10 (b) The stator core 30a shown is made of Figure 6 (a) Stator core 30 as already described.

[0128] like Figure 10 As shown in (a), stator cores 30b without small holes 70a, 70b, and 70c are stacked on the side of the compression mechanism section 2 and on the side away from the compression mechanism section 2, and stator cores 30a with small holes 70a, 70b, and 70c are stacked between these stator cores 30b.

[0129] The variation of the tooth direction (radial direction) force of stator core 30a is smaller than that of stator core 30b. Therefore, especially in scroll compressors where the rotor 3a is supported by both the compression mechanism section 2 and the bearing 7b, by arranging the stator core 30a, which has a smaller variation of tooth direction (radial direction) force, at a position farther from the compression mechanism section 2, the deflection of the shaft 8 can be reduced.

[0130] When the rotor 3a is supported by both the compression mechanism section 2 and the bearing 7b, by arranging the stator core 30a near the center between the shaft supports, which are prone to shaft deflection, the deflection of the shaft 8 is reduced, thereby providing a compressor 10 with low vibration, low noise, and high reliability. Alternatively, when a highly rigid shaft 8 with a larger diameter and longer shaft than the bearing 7b side is used on the compression mechanism section 2 side, the stator core 30b can be arranged on the compression mechanism section 2 side, and the stator core 30a can be arranged at a position farther away from the compression mechanism section 2 side.

[0131] In addition, Figure 10 In (a), a compressor with the compression mechanism 2 positioned above the permanent magnet synchronous motor 3 is shown. However, the same applies to compressors with the compression mechanism 2 positioned below the permanent magnet synchronous motor 3 or compressors 10 with the compression mechanism 2 and the permanent magnet synchronous motor 3 arranged laterally.

[0132] In addition, Figure 10 (b) shows Figure 6 (a) shows the stator core 30, but using Figure 3 , Figure 6 (b) to Figure 6 (e) and Figure 7 (a) to Figure 7 The stator core 30 shown in (f) is the same.

[0133] Alternatively, the small-hole configuration core shown in this embodiment can also be used in motors that use so-called segmented cores and stators. The segmented core is a core that is divided in the circumferential direction, arranged and combined in the circumferential direction after a high-density winding is provided on the stator, and the stator is a stator that is tightly attached in the circumferential direction after a high-density winding is provided in a state where a part of the stator yoke is engaged, and the yoke is deformed or movable.

[0134] Compared to a conventional stator formed integrally in the circumferential direction, a stator with a segmented core and a portion of the stator yoke joined together has lower rigidity. Furthermore, in a T-shaped stator where the angle between the teeth and the yoke is right-angled due to the use of high-density windings, rigidity remains low even if the width of the yoke portion between the teeth is reduced. The permanent magnet synchronous motor of this invention can also reduce radial force variation in the segmented core, achieving low noise and high efficiency due to low vibration.

[0135] Industrial availability

[0136] The permanent magnet synchronous motor of the present invention is suitable for scroll compressors, rotary compressors, and can also be used in reciprocating compressors and other compressors.

[0137] Explanation of reference numerals in the attached figures

[0138] 1. Sealed container

[0139] 2. Compression Mechanism

[0140] 2a Fixed scroll component

[0141] 2b Cyclone Scroll

[0142] 3 Permanent Magnet Synchronous Motor

[0143] 3a Rotor

[0144] 3b stator

[0145] 4. Oil storage section

[0146] 5. Inhalation tube

[0147] 6. Discharge pipe

[0148] 7a Main bearing assembly

[0149] 7b bearing

[0150] 8 axes (rotor rotation axes)

[0151] 8a Eccentric shaft

[0152] 9 Rotation restriction agencies

[0153] 10 Compressors

[0154] 11 Permanent Magnets

[0155] 30, 30a, 30b stator cores

[0156] 31 Stator Yoke

[0157] 32 stator teeth

[0158] 32a Stator tooth base

[0159] 32b Stator tooth front end

[0160] 35 Opposite face

[0161] 40 slots

[0162] 50 windings

[0163] 61 Condenser

[0164] 62 Pressure reducing device

[0165] 63 Evaporator

[0166] 70 small hole group

[0167] 70a, 70b, 70c, 70d, 71a, 71b, 72a, 72b, 73a, 73b small holes

[0168] 70x Imaginary Center

[0169] t width dimension

[0170] A. Imaginary center line at the tooth base.

Claims

1. A permanent magnet synchronous motor, characterized in that, have: A rotor configured to rotate about a rotation axis; and The stator, which is separated from the rotor by an air gap, The stator has: A ring-shaped stator yoke centered on the rotation axis; A plurality of stator teeth extending from the stator yoke toward the rotor; and The grooves formed between the stator teeth A winding is arranged in the slot. The stator teeth have: The stator tooth base on which the winding is wound; and The stator tooth front end portion, located at the front end of the stator tooth base, has a facing surface opposite to the rotor. At the front end of the stator teeth, a group of small holes consisting of at least two small holes is provided. The cross-sectional shape of each of the small holes is a circle with the same diameter. The distance between each small hole and the opposite surface is less than the diameter of the small hole, and each small hole is equidistant from the opposite surface, thereby arranging the small holes in a direction along the opposite surface. The small hole group is configured in the range where the variation of the tooth direction force acting on the front end of the stator tooth decreases.

2. The permanent magnet synchronous motor as described in claim 1, characterized in that: Let the center of the circumferential width dimension of the stator tooth base be the imaginary center line of the tooth base. The plurality of holes are configured such that the imaginary center of the group of holes is located in the opposite direction to the rotational direction of the rotor relative to the imaginary center line of the tooth base.

3. The permanent magnet synchronous motor as described in claim 1 or 2, characterized in that: The number of holes is three or more.

4. The permanent magnet synchronous motor as described in claim 1 or 2, characterized in that: The stator is constructed by stacking multiple stator cores axially on the rotating shaft. The small holes are formed in a portion of the stator core. The small hole is not formed in the other stator cores.

5. A compressor, characterized in that: Using the permanent magnet synchronous motor as described in claim 4 The permanent magnet synchronous motor and the compression mechanism are connected by a shaft. A stator core without the small hole is disposed on the side of the compression mechanism. The stator core with the small hole is disposed on the side away from the compression mechanism.

6. A compressor, characterized in that: Using any one of the permanent magnet synchronous motors according to claims 1 to 4 The permanent magnet synchronous motor and the compression mechanism are connected by a shaft. The refrigerant is compressed using the aforementioned compression mechanism.

7. A device, characterized in that: The compressor, condenser, pressure reducing device, and evaporator described in claim 5 or 6 are connected in a ring by piping.

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