Permanent magnet motor, compressor and household appliance

Abstract

The application provides a permanent magnet motor, a compressor and a household appliance. The permanent magnet motor comprises a stator and a rotor, the rotor comprises a rotor core, the rotor core is provided with a plurality of magnetic pole units, the plurality of magnetic pole units are uniformly distributed along the circumference of the rotor core, and the magnetic field generated by the stator and the magnetic field of the adjacent magnetic pole unit have an electric angle, and the electric angle ranges from 20 DEG to 70 DEG. The permanent magnet motor provided by the application sets the plurality of magnetic pole units on the rotor core, and the magnetic field generated by the stator and the magnetic field of the magnetic pole unit have an electric angle, and the electric angle ranges from 20 DEG to 70 DEG, so that when the permanent magnet motor operates in a high-speed weak magnetic state, the high-order harmonic component is reduced, the induced potential waveform is reduced or avoided from being distorted, and then the peak value of the induced voltage is reduced, so that the back electromotive force value is prevented from exceeding the maximum input voltage that can be provided by the controller, and the normal operation of the permanent magnet motor is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric machines, and more particularly relates to a permanent magnet electric machine, a compressor and a household appliance. BACKGROUND

[0002] At present, more and more requirements for miniaturization of electric machines are proposed, and the electric machines are required to output high torque while rotating at high speed. In order to generate high torque in a wide speed range, the electric machine often utilizes the synthesis of permanent magnet torque and reluctance torque to output torque. Generally, mounting holes are arranged in the rotor core, and magnets are embedded, so that the magnetic reluctance of the magnetic circuit of the d-axis (i.e. direct axis) and the q-axis (i.e. quadrature axis) of the rotor core is different, so that the stator magnetic motive force of the electric machine generates a reluctance torque on the rotor side, and the permanent magnet torque based on the magnets themselves makes the electric machine generate a synthesized torque. When the electric machine is running at high speed, it is often in a state of flux weakening, and the induced electromotive force waveform is prone to distortion, which leads to a serious high-order harmonic content that exceeds the fundamental wave. After distortion, the back electromotive force value of the electric machine is prone to exceed the maximum input voltage that the controller can provide, thereby affecting the normal operation of the electric machine. SUMMARY

[0003] The purpose of the embodiments of the application is to provide a permanent magnet electric machine, a compressor and a household appliance, so as to solve the problem that the induced electromotive force waveform of the permanent magnet electric machine in the prior art is prone to distortion in a high-speed flux-weakening state, which leads to a serious high-order harmonic content that exceeds the fundamental wave.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the embodiments of the application is as follows: a permanent magnet electric machine is provided, which comprises a stator and a rotor. The stator comprises a stator core, the stator core comprises a plurality of stator teeth and a stator yoke supporting the plurality of stator teeth, a plurality of stator teeth surround a stator inner hole, a stator slot is formed between two adjacent stator teeth, and a winding is wound on the stator teeth. The rotor is rotatably installed in the stator inner hole, the rotor comprises a rotor core, the rotor core is provided with a plurality of magnetic pole units, the plurality of magnetic pole units are uniformly distributed along the circumferential direction of the rotor core, each magnetic pole unit comprises a plurality of layers of magnet mounting holes arranged in the radial direction of the rotor core, each magnet mounting hole is provided with a permanent magnet, and the end portion of each magnet mounting hole is arranged adjacent to the outer circumferential surface of the rotor core. The magnetic field generated by the stator and the magnetic field of the adjacent magnetic pole unit have an electrical angle, and the range of the electrical angle is 20° to 70°.

[0005] In an optional embodiment, the end portion of each magnet mounting hole is provided with a magnetic barrier hole in the direction of the outer circumferential surface of the rotor core, and the width of each magnetic barrier hole is less than or equal to the width of the corresponding magnet mounting hole.

[0006] In an optional embodiment, the multilayer magnet mounting holes include a first mounting hole and at least one layer of second mounting holes arranged radially along the rotor core. The two ends of the first mounting hole are bent toward the outer peripheral surface of the rotor core. The first mounting hole is symmetrically arranged about one radial surface of the rotor core. The number of second mounting holes in each layer is two. The first mounting hole is located between the two second mounting holes in each layer. The permanent magnet includes a first permanent magnet disposed in the first mounting hole and a second permanent magnet disposed in the second mounting hole.

[0007] In an optional embodiment, a first magnetic guide position is formed between the magnetic barrier holes at both ends of the first mounting hole, a second magnetic guide position is formed between two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit, and a third magnetic guide position is formed between two adjacent magnetic barrier holes in two adjacent magnetic pole units. The width of the second magnetic guide position is less than or equal to the slot width of the stator slot.

[0008] In an optional embodiment, a first magnetic guide position is formed between the magnetic barrier holes at both ends of the first mounting hole, a second magnetic guide position is formed between two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit, and a third magnetic guide position is formed between two adjacent magnetic barrier holes in two adjacent magnetic pole units, wherein the width of the third magnetic guide position is less than or equal to the slot width of the stator slot.

[0009] In an optional embodiment, a first magnetically conductive position is formed between the magnetic barrier holes at both ends of the first mounting hole, a second magnetically conductive position is formed between two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit, and a third magnetically conductive position is formed between two adjacent magnetic barrier holes in two adjacent magnetic pole units; the slot opening of the stator slot is offset from the second magnetically conductive position, and the slot opening of the stator slot is offset from the third magnetically conductive position.

[0010] In an optional embodiment, the magnet mounting holes of each layer are bent into a U-shape, and the two ends of the magnet mounting holes of each layer extend toward the outer peripheral surface of the rotor core. The two ends of the second mounting hole are respectively provided with the second permanent magnet, and a flow hole is formed in the middle of the second mounting hole.

[0011] In an optional embodiment, the minimum distance between the first mounting hole and the second mounting hole is less than or equal to the width of the second mounting hole.

[0012] In one optional embodiment, the first mounting hole is arc-shaped, and the areas at both ends of the second mounting hole corresponding to the mounting of the second permanent magnet are both rectangular.

[0013] In an alternative embodiment, the distance between the first mounting hole and the second mounting hole is gradually reduced in a direction along the radial direction of the rotor core toward the outer peripheral surface of the rotor core.

[0014] In an optional embodiment, the magnetic barrier hole at the end of the first mounting hole is a shrinkage hole, the width of which gradually decreases along the radial direction of the rotor core from the first mounting hole to the outer peripheral surface of the rotor core, and the magnetic barrier hole at the end of the second mounting hole is a stepped hole, the width of which is smaller than the width of the second mounting hole.

[0015] In an optional embodiment, the rotor core is constructed by stacking rotor laminations, and the distance between each magnetic barrier hole and the outer peripheral surface of the rotor core is greater than or equal to the thickness of any rotor lamination.

[0016] Another objective of this application is to provide a compressor, including a housing, in which a permanent magnet motor as described in the above embodiments is installed.

[0017] Another objective of this application is to provide a household appliance, including a permanent magnet motor as described in the above embodiments.

[0018] The beneficial effects of the permanent magnet motor provided in this application embodiment are as follows: Compared with the prior art, the permanent magnet motor in this application embodiment, by setting multiple magnetic pole units on the rotor core and having an electrical angle between the magnetic field generated by the stator and the magnetic field of the magnetic pole unit, the range of the electrical angle is set to 20° to 70°, so that when the permanent magnet motor is running in a high-speed field weakening state, the high-order harmonic components are reduced, the distortion of the induced electromotive force waveform is reduced or avoided, and the peak value of the induced voltage is reduced, so as to avoid the back electromotive force value from exceeding the maximum input voltage that the controller can provide, and ensure the normal operation of the permanent magnet motor.

[0019] The beneficial effects of the compressor provided in this application embodiment are as follows: Compared with the prior art, the compressor in this application embodiment uses the permanent magnet motor of the above embodiment, and has the beneficial effects of the permanent magnet motor, which will not be repeated here.

[0020] The beneficial effects of the household appliances provided in this application embodiment are as follows: Compared with the prior art, the household appliances in this application embodiment use the permanent magnet motor of the above embodiment, and have the beneficial effects of the permanent magnet motor, which will not be repeated here. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or exemplary technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A cross-sectional view of a permanent magnet motor provided in an embodiment of this application;

[0023] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the central rotor;

[0024] Figure 3 for Figure 2 Enlarged view of the central area;

[0025] Figure 4 A schematic diagram showing the unfolded structure of the stator and rotor of a permanent magnet motor provided in an embodiment of this application;

[0026] Figure 5 A schematic diagram showing the relative positions of the rotor magnetic barrier and the stator slot when the stator and rotor of the permanent magnet motor provided in this embodiment are unfolded;

[0027] Figure 6 A schematic diagram of the relative positions of the rotor magnetic barrier and the stator slot when the stator and rotor of another permanent magnet motor provided in this application are unfolded;

[0028] Figure 7 A bar chart comparing the back EMF harmonic components of a permanent magnet motor provided in an embodiment of this application;

[0029] Figure 8 for Figure 5 and Figure 6 A bar graph comparing the output torque of two permanent magnet motors at the same current.

[0030] The main markings in the attached figures are as follows:

[0031] 100-Permanent magnet motor;

[0032] 10-Stator; 11-Stator core; 111-Stator yoke; 112-Stator tooth; 113-Stator slot; 1131-Slot opening;

[0033] 20-Rotor; 21-Rotor core; 210-Magnetic guide section; 211-First magnetic guide position; 212-Second magnetic guide position; 213-Third magnetic guide position; 22-Magnetic pole unit; 220-Symmetry plane; 23-Magnet mounting hole; 231-First mounting hole; 232-Second mounting hole; 2321-Flow hole; 24-Magnetic barrier hole; 241-Contraction hole; 242-Stepped hole; 251-First thin-walled structure; 252-Second thin-walled structure; 26-Permanent magnet; 261-First permanent magnet; 262-Second permanent magnet; 27-Center hole; 28-Rotor magnetic barrier; 281-First rotor magnetic barrier; 282-Second rotor magnetic barrier. Detailed Implementation

[0034] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0036] In the description of this application, "a plurality of" means two or more, unless otherwise expressly specified. "Several" means one or more, unless otherwise expressly specified. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In this specification, references to "one embodiment," "some embodiments," or simply "embodiment" mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. Furthermore, in one or more embodiments, specific features, structures, or characteristics may be combined in any suitable manner.

[0039] Please see Figures 1 to 3 The permanent magnet motor 100 provided in this application will now be described. The permanent magnet motor 100 includes a stator 10 and a rotor 20. The rotor 20 is installed in the stator 10 and is driven to rotate by the stator 10.

[0040] The stator 10 includes a stator core 11, which includes a plurality of stator teeth 112 and a stator yoke 111 supporting the stator teeth 112. The stator teeth 112 form a stator inner hole to mount the rotor 20 in the stator inner hole. A stator slot 113 is formed between two adjacent stator teeth 112, and a winding is wound on the stator teeth 112, with the winding located in the stator slot 113. In this embodiment, the number of stator slots 113 is thirty-six slots. It can be understood that the number of stator slots 113 can also be set to other numbers.

[0041] Optionally, the stator 10 can be nested in a housing made of materials such as iron or aluminum to secure it. Of course, the housing can also be made of materials such as plastic. Understandably, the housing can also be injection molded into a single structure with the stator 10. The rotor 20 can be fixed to the housing via bearings to ensure that the rotor 20 and stator 10 are coaxially aligned, facilitating smooth rotation of the rotor 20 by the stator 10. Understandably, in use, the housing can also be omitted, and the stator 10 and rotor 20 can be directly installed in the application equipment.

[0042] The stator core 11 can be formed by stacking stator laminations to reduce iron losses and improve output torque and efficiency. The stator laminations can be made of silicon steel sheets to reduce costs.

[0043] The rotor 20 includes a rotor core 21, which can be formed by laminating rotor laminations to reduce iron losses and improve output torque and efficiency. The rotor laminations can be made of silicon steel sheets to reduce costs. Furthermore, considering the stamping process of silicon steel sheets and their mechanical strength during use, necessary chamfering can be applied to the edges and corners when machining the first mounting hole, second mounting hole, and flow hole.

[0044] The rotor core 21 is provided with a central hole 27. In use, the rotating shaft can be inserted into the central hole 27 to install the rotor core 21 on the rotating shaft so that the rotor 20 can drive the rotating shaft to rotate.

[0045] The rotor core 21 contains multiple magnetic pole units 22, with adjacent magnetic pole units 22 having different polarities. These magnetic pole units 22 are evenly distributed circumferentially along the rotor core 21. In this embodiment, the rotor core 21 has six sets of magnetic pole units 22. Understandably, the number of magnetic pole units 22 can also be other than those specified.

[0046] Each magnetic pole unit 22 includes multi-layer magnet mounting holes 23, which are arranged radially along the rotor core 21. A permanent magnet 26 is provided in each magnet mounting hole 23. The end of each magnet mounting hole 23 is located adjacent to the outer peripheral surface of the rotor core 21. During use, the permeability at the magnet mounting holes 23 on the rotor core 21 is very small, while the permeability at other locations on the rotor core 21 is relatively large. This causes the magnet mounting holes 23 to define the direction of magnetic flux flow in the rotor core 21, thereby forming an induced magnetic field in the rotor core 21. The induced magnetic field forms magnetic poles and, when the stator 10 magnetic field drives the rotor 20 to rotate, generates reluctance torque.

[0047] A permanent magnet 26 is installed in the magnet mounting hole 23. The permanent magnet 26 can provide a permanent magnetic field, and when used in conjunction with the stator 10, it can generate a permanent magnetic torque, thereby increasing the output torque of the manufactured permanent magnet motor 100. Thus, the multi-layer magnet mounting holes 23 and the permanent magnet 26 work together to form a magnetic pole unit 22 in the rotor core 21.

[0048] The magnetic field generated by the stator 10 has an electrical angle with the magnetic field of the adjacent magnetic pole unit 22, which ranges from 20° to 70°. In other words, by controlling the range of the electrical angle between the magnetic field of the stator 10 and the magnetic field of the magnetic pole unit 22 to be 20° to 70°, the high-order harmonic components can be effectively reduced, making the induced electromotive force waveform more stable and less prone to distortion. This, in turn, reduces the peak value of the induced voltage, thereby avoiding excessively high back electromotive force and ensuring the normal operation of the permanent magnet motor 100.

[0049] Compared with the prior art, the permanent magnet motor 100 provided in this application embodiment has multiple magnetic pole units 22 on the rotor core 21, and the magnetic field generated by the stator 10 and the magnetic field of the magnetic pole unit 22 have an electrical angle, and the range of the electrical angle is set to 20° to 70°. This reduces the high-order harmonic components and reduces or avoids the distortion of the induced electromotive force waveform when the permanent magnet motor 100 is running in a high-speed field weakening state, thereby reducing the peak value of the induced voltage and preventing the back electromotive force value from exceeding the maximum input voltage that the controller can provide, thus ensuring the normal operation of the permanent magnet motor 100.

[0050] Because a permanent magnet retains its original magnetic properties until the reverse magnetic field passing through it reaches a certain threshold, but if this threshold is exceeded, the magnetic flux density decreases, resulting in irreversible demagnetization that cannot restore the original magnetic properties. If irreversible demagnetization occurs, the residual magnetic flux density of the permanent magnet decreases, the current used to generate torque increases, leading to deterioration in motor efficiency, control degradation, and reduced reliability.

[0051] In one embodiment, see Figures 1 to 3 Each magnet mounting hole 23 has a magnetic barrier hole 24 at its end. The magnetic barrier hole 24 protrudes from the end of the corresponding magnet mounting hole 23 toward the outer peripheral surface of the rotor core 21. The width of each magnetic barrier hole 24 is less than or equal to the width of the corresponding magnet mounting hole 23. Since the permeability of the magnetic barrier hole 24 is lower than that of the rotor core 21, its magnetic reluctance is also larger. Therefore, the magnetic barrier hole 24 constitutes a magnetic shielding wall in the magnetic circuit of the rotor 20 of the magnetic pole unit 22, making it difficult for magnetic flux to pass through. That is, a leakage flux suppression structure is formed at the magnetic barrier hole 24. In other words, each magnetic barrier hole 24 forms a rotor magnetic barrier. The distance between the magnetic barrier hole 24 and the outer peripheral surface of the rotor core 21 is small, forming a thin-walled structure. Magnetic flux tends to concentrate at this thin-walled structure, and to reduce magnetic leakage during operation of the permanent magnet motor 100, this thin-walled structure is often made thinner, resulting in saturated magnetic flux at this location. This causes the armature reaction demagnetizing magnetic field to pass through the end of the permanent magnet 26. Therefore, the magnetic barrier hole 24 is provided to reduce the amount of magnetic flux passing through the permanent magnet 26, thus improving demagnetization resistance.

[0052] In one embodiment, the multi-layer magnet mounting hole 23 includes a first mounting hole 231 and at least one layer of second mounting holes 232. The first mounting hole 231 is located radially outward of the rotor core 21, and the second mounting hole 232 is located radially inward of the first mounting hole 231 along the rotor core 21. In this embodiment, the second mounting hole 232 is one layer; it can be understood that the second mounting hole 232 can also be configured as two layers, three layers, etc. That is, along the radial direction of the rotor core 21 from the outside to the inside, the multi-layer magnet mounting hole 23 can also include a third mounting hole, a fourth mounting hole, etc., meaning that along the radial direction of the rotor core 21 from the outside to the inside, the multi-layer magnet mounting hole 23 can also include three layers, four layers, etc. The number of second mounting holes 232 in each layer is two, and these two second mounting holes 232 are located on opposite sides of the first mounting hole 231, that is, the first mounting hole 231 is located between the two second mounting holes 232 in each layer.

[0053] The first mounting hole 231 is bent, with both ends bent toward the outer circumferential surface of the rotor core 21, and the middle part bent toward the central hole 27 of the rotor core 21. Therefore, the first mounting hole 231 can be bent into a U-shape, arc shape, or other shapes. The first mounting hole 231 is symmetrically arranged about a radial plane of the rotor core 21, meaning it has a symmetrical structure, and its symmetrical plane 220 is a radial plane of the rotor core 21. A radial plane refers to a plane arranged radially along the rotor core 21. This allows the q-axis (i.e., the direct axis) of the magnetic pole unit 22 to be located on the symmetrical plane 220 of the first mounting hole 231. Furthermore, it ensures the symmetry of the magnetic field of the magnetic pole unit 22, facilitating design and control, reducing harmonics, and making the q-axis magnetic flux path approximately sinusoidal.

[0054] A first permanent magnet 261 is installed in the first mounting hole 231, and a second permanent magnet 262 is installed in the second mounting hole 232. That is, the permanent magnet 26 includes a first permanent magnet 261 and a second permanent magnet 262. A permanent magnetic field can be provided by the first permanent magnet 261 and the second permanent magnet 262, and thus, when used in conjunction with the stator 10, a permanent magnetic torque can be generated, thereby increasing the output torque of the manufactured permanent magnet motor 100.

[0055] In one embodiment, the mounting holes 23 of each layer of magnets are bent into a U-shape, and the two ends of the mounting holes 23 of each layer of magnets extend toward the outer peripheral surface of the rotor core 21. The two ends of the second mounting hole 232 are respectively provided with a second permanent magnet 262. A flow hole 2321 is formed in the middle of the second mounting hole 232. The setting of the flow hole 2321 can form an air magnetic barrier, which helps the air-liquid flow, increases the air-liquid flow area, reduces the amount of magnets used, thereby reducing costs and reducing the cumbersome complexity of the motor assembly process.

[0056] Understandably, the first permanent magnet 261 can be a rare-earth sintered magnet, a rare-earth bonded magnet, a ferrite sintered magnet, a ferrite bonded magnet, etc. The second permanent magnet 262 can be a rare-earth sintered magnet, a rare-earth bonded magnet, a ferrite sintered magnet, a ferrite bonded magnet, etc.

[0057] The permanent magnets used in the permanent magnet motor 100, such as the first permanent magnet 261 and the second permanent magnet 262, can be any type of magnet selected from rare-earth sintered magnets, rare-earth bonded magnets, ferrite sintered magnets, and ferrite bonded magnets. However, rare-earth magnets are more expensive, while ferrite magnets are relatively more cost-effective. However, due to the low remanence of ferrite materials (currently known materials do not exceed 0.5T), the ferrite permanent magnet motor 100 relies solely on permanent magnet torque output, resulting in a relatively low output torque. This embodiment employs a permanent magnet motor 100 that combines permanent magnet torque and reluctance torque, which can improve output torque. Under the same current conditions, it can improve performance, and compared to a pure synchronous reluctance motor, the use of permanent magnets increases the utilization rate of the unit current output power of the permanent magnet motor 100. Simultaneously, the power factor of the manufactured permanent magnet motor 100 is not lower than that of an induction motor of the same power.

[0058] Secondly, to increase the proportion of reluctance torque output of the permanent magnet motor 100, the phase current needs to exceed the induced electromotive force of the rotor 20. The currents of the d-axis (i.e., direct axis) and q-axis (i.e. quadrature axis) have a 90° phase difference in electrical angle. The product of id (i.e., direct axis current) and iq (i.e. quadrature axis current) has the greatest influence when the electrical angle difference is 45°. Secondly, the larger the inductance difference between the q-axis and d-axis, the more helpful it is to output reluctance torque.

[0059] Generally, the d-axis direction corresponds to the direction in which the permanent magnet (such as the permanent magnet 26 formed by the combination of the first permanent magnet 261 and the second permanent magnet 262) and the magnetic pole unit 22 generate magnetic flux. Therefore, the d-axis direction penetrates the air magnetic barrier formed by the permanent magnet 26, the magnetic pole unit 22, the first mounting hole 231, the second mounting hole 232, and the flow hole 2321 of the magnetic pole unit 22. When the first permanent magnet 261 and the second permanent magnet 262 are installed in the first mounting hole 231 and the second mounting hole 232, their permeability is approximately the same as that of air. In other words, the d-axis direction penetrates the air magnetic barrier of the permanent magnet 26 and the magnetic pole unit 22, which has a permeability approximately the same as that of air. This increases the magnetic reluctance along the d-axis, and the increase in magnetic reluctance reduces the inductance along the d-axis.

[0060] The magnetic flux in the Q-axis direction is directed towards the side of the permanent magnet 26. In other words, the magnetic flux in the q-axis direction mainly passes through the magnetic conduction space between the pole units 22 and the permanent magnet. The area between the pole units 22, also referred to as the inter-pole space, refers to the space between the second mounting hole 232 and the second mounting hole 232 of the adjacent pole unit 22. The area between the permanent magnets refers to the space between the first permanent magnet 261 and the second permanent magnet 262, as well as the inner side of the bent first permanent magnet 261. The inner side of the bent first permanent magnet 261 also refers to the side of the first permanent magnet 261 closest to the outer circumference of the rotor core 21. Because the magnetic flux in the q-axis direction passes through the magnetic conduction space between the pole units and the permanent magnet, the magnetic reluctance in the q-axis direction is relatively small, and the inductance is correspondingly large.

[0061] As can be seen from the above, in this embodiment, the inductance difference between the q-axis and the d-axis can be increased, thereby increasing the reluctance torque of the permanent magnet motor 100, and thus enabling the permanent magnet torque and reluctance torque of the permanent magnet motor 100 to output a larger torque.

[0062] Furthermore, in this embodiment, the curved first mounting hole 231 and second mounting hole 232 ensure that the shape of the magnet hole formed by the first mounting hole 231 and the second mounting hole 232 is approximately sinusoidal along the magnetic flux path equal to the q-axis. The orientation orthogonal to the shape of this magnet hole results in the magnetic flux of the permanent magnet 26 being close to a sine wave. The first permanent magnet 261 is fitted into the first mounting hole 231, and its curved arrangement, combined with the second permanent magnet 262 in the second mounting hole 232, increases the sinusoidal saturation of magnetic flux per unit area, contributing to increased output torque of the manufactured permanent magnet motor 100. Additionally, the flow hole 2321 reduces the magnetic flux passing through the first permanent magnet 261 and the second permanent magnet 262, thus reducing short circuits and improving demagnetization resistance.

[0063] In one embodiment, a first magnetically conductive position 211 is formed between the magnetic barrier holes 24 at both ends of the first mounting hole 231, and a second magnetically conductive position 212 is formed between the two magnetic barrier holes 24 corresponding to the adjacent layer magnet mounting holes 23 in the magnetic pole unit 22. In this embodiment, a second magnetically conductive position 212 is formed between the end of the second mounting hole 232 and the adjacent end of the first mounting hole 231, and a third magnetically conductive position 213 is formed between the two adjacent magnetic barrier holes 24 of the two adjacent magnetic pole units 22. The first magnetically conductive position 211, the second magnetically conductive position 212 and the third magnetically conductive position 213 on the rotor core 21 constitute the magnetically conductive part 210 of the rotor 20 in order to increase the magnetic flux from the stator 10.

[0064] In one embodiment, the second magnetic guide position 212 is offset relative to the slot opening 1131 of the stator slot 113 to change the magnetic resistance of the gap between the rotor 20 and the stator 10, so that the magnetic flux waveform is close to the sine wave as the ideal waveform shape, thereby reducing the high-order harmonic components of the magnetic flux density of the stator 10 and reducing the proportion of harmonic content in the back electromotive force of the permanent magnet motor 100.

[0065] In one embodiment, the third magnetic guide position 213 is formed as an inter-pole magnetic guide position of the rotor 20. The third magnetic guide position 213 is relatively misaligned with the slot opening 1131 of the stator slot 113 to change the magnetic resistance of the gap between the rotor 20 and the stator 10, so that the magnetic flux waveform is close to the sine wave as the ideal waveform shape, thereby reducing the high-order harmonic components of the magnetic flux density of the stator 10 and reducing the proportion of harmonic content in the back electromotive force of the permanent magnet motor 100.

[0066] In one embodiment, the second magnetic guide position 212 is offset relative to the slot opening 1131 of the stator slot 113, and the third magnetic guide position 213 is offset relative to the slot opening 1131 of the stator slot 113. This can better change the magnetic reluctance of the gap between the rotor 20 and the stator 10, so that the magnetic flux waveform is close to the ideal waveform shape of a sine wave. This reduces the high-order harmonic components of the magnetic flux density of the stator 10 and reduces the proportion of harmonic content in the back electromotive force of the permanent magnet motor 100.

[0067] In one embodiment, see Figures 1 to 3 The width H1 of the second magnetic guide position 212 is less than or equal to the width T1 of the slot opening 1131 of the stator slot 113, so as to ensure good structural strength of the rotor core 21, increase the magnetic flux from the stator 10, and thus improve the torque.

[0068] In one embodiment, see Figures 1 to 3 The width H2 of the third magnetic guide position 213 is less than or equal to the width T1 of the slot opening 1131 of the stator slot 113, so as to ensure good structural strength of the rotor core 21, increase the magnetic flux from the stator 10, and thus improve the torque.

[0069] In one embodiment, see Figure 6 When the third magnetic conductor 213 is made wider, such as Figure 6 In the region corresponding to the dashed line F, the slot opening 1131 of stator slot 113 is easily aligned with the third magnetic conductor 213, and the magnetic field waveform of permanent magnet motor 100 is also prone to distortion, resulting in high back EMF harmonic content in permanent magnet motor 100. Please refer to the following: Figures 1 to 3 The width H2 of the third magnetic guide position 213 is less than or equal to the width T1 of the slot opening 1131 of the stator slot 113, such as Figure 6The solid line area not only ensures the good structural strength of the rotor core 21 and increases the magnetic flux from the stator 10, thereby improving the torque, but also allows the slot opening 1131 of the stator slot 113 to be offset from the third magnetic position 213 on the rotor 20. This can change the magnetic resistance of the gap between the rotor 20 and the stator 10, making the magnetic flux waveform close to the ideal sine wave, thereby reducing the high-order harmonic components of the magnetic flux density of the stator 10 and reducing the proportion of harmonic content in the back electromotive force of the permanent magnet motor 100.

[0070] In one embodiment, in order to maximize the permanent magnet torque output of the first permanent magnet 261, the end of the first mounting hole 231 is brought as close as possible to the adjacent second mounting hole 232. The minimum distance W4 between the first mounting hole 231 and the second mounting hole 232 can be set to be less than or equal to the width W2 of the second mounting hole 232.

[0071] In one embodiment, the second permanent magnet 262 in the second mounting hole 232 can be configured as a rectangular magnet to facilitate manufacturing and installation, and can be combined with the first permanent magnet 261 to better improve the sinusoidal saturation of magnetic flux per unit area. Understandably, the second permanent magnet 262 can also be configured in other shapes, which are not limited here.

[0072] In one embodiment, the first permanent magnet 261 in the first mounting hole 231 can be configured as an arc-shaped magnetic tile to facilitate processing, manufacturing, and installation. It can also be combined with the second permanent magnet 262 to better improve the sinusoidal saturation of magnetic flux per unit area. Understandably, the first permanent magnet 261 can also be bent into other shapes, which are not limited to this embodiment.

[0073] In one embodiment, the areas at both ends of the second mounting hole 232 where the second permanent magnet 262 is mounted are rectangular to facilitate design and manufacturing.

[0074] In one embodiment, the distance between the first mounting hole 231 and the second mounting hole 232 is gradually reduced in the direction from the radial direction of the rotor core 21 toward the outer peripheral surface of the rotor core 21. That is, the distance between the first mounting hole 231 and the second mounting hole 232 is gradually reduced, and the closer to the outer peripheral surface of the rotor core 21, the shorter the distance between the first mounting hole 231 and the second mounting hole 232, so as to increase the magnetic flux density between the first mounting hole 231 and the second mounting hole 232, thereby increasing the reluctance torque.

[0075] The permanent magnet motor 100 using ferrite permanent magnets has a lower magnetic flux density value than that of permanent magnets made of rare earth materials. In this embodiment, the closer to the outer periphery of the rotor core 21, the shorter the distance between the first mounting hole 231 and the second mounting hole 232. This can increase the saturation magnetic flux density between the first mounting hole 231 and the second mounting hole 232 to 2.0T, thereby improving the utilization rate of the rotor core 21 and the efficiency of the permanent magnet motor 100. Moreover, it can prevent the magnetic flux density of the rotor core 21 from becoming oversaturated, avoid magnetic flux deformation, and prevent torque reduction or pulsation caused by magnetic flux deformation.

[0076] In one embodiment, the first mounting hole 231 can be arc-shaped for ease of design and fabrication. Understandably, the outline of the first mounting hole 231 near the outer circumferential surface of the rotor core 21 can be configured as a symmetrical curve structure approximating the q-axis magnetic circuit channel. The symmetry plane 220 of this curve structure is the symmetry plane 220 of the first mounting hole 231. One side of this curve structure can be configured as a semi-hyperbola, a semi-exponential function curve, a semi-logarithmic function curve, a semi-tangent curve, etc. A semi-hyperbola is a curve on one side of the hyperbola's axis of symmetry. A semi-exponential function curve is half of an exponential function curve. A semi-logarithmic function curve is half of a logarithmic function curve. A semi-tangent curve is half of a tangent curve.

[0077] In one embodiment, the magnetic barrier hole 24 at the end of the first mounting hole 231 is a contraction hole 241. The width of the contraction hole 241 gradually decreases from the first mounting hole 231 to the outer peripheral surface of the rotor core 21. That is, contraction holes 241 are provided at both ends of the first mounting hole 231. The contraction hole 241 protrudes from the corresponding end of the first mounting hole 231 toward the outer peripheral surface of the rotor core 21. The width of the contraction hole 241 gradually decreases from the first mounting hole 231 to the outer peripheral surface of the rotor core 21. Since the permeability of the contraction hole 241 is lower than that of the rotor core 21, its magnetic resistance is also larger. Thus, the contraction hole 241 constitutes a magnetic shielding wall in the magnetic circuit of the rotor 20 of the magnetic pole unit 22, which makes it difficult for magnetic flux to pass through. That is, a leakage flux suppression structure is formed at the contraction hole 241. The distance between the contraction hole 241 and the outer peripheral surface of the rotor core 21 is small, forming a first thin-walled structure 251 between them. Magnetic flux tends to concentrate at this thin-walled structure 251, and during operation of the permanent magnet motor 100, to reduce magnetic leakage, this structure is often made thinner, resulting in saturation of the magnetic flux at this location. This causes the armature reaction demagnetizing magnetic field to pass through the end of the first permanent magnet 261. Therefore, the contraction hole 241 is designed to reduce the magnetic flux passing through the first permanent magnet 261, thus improving demagnetization resistance.

[0078] In one embodiment, the magnetic barrier hole 24 at the end of the second mounting hole 232 is a stepped hole 242. The width of the stepped hole 242 is smaller than the width of the second mounting hole 232. That is, the second mounting hole 232 is provided with a stepped hole 242 at one end near the outer peripheral surface of the rotor core 21. The stepped hole 242 protrudes from the second mounting hole 232 toward the outer peripheral surface of the rotor core 21. The width of the stepped hole 242 is smaller than the width of the second mounting hole 232. Since the permeability of the stepped hole 242 is lower than the permeability of the rotor core 21, its magnetic resistance is also larger. Thus, the stepped hole 242 constitutes a magnetic shielding wall in the magnetic circuit of the rotor 20 of the magnetic pole unit 22, which makes it difficult for magnetic flux to pass through. That is, a leakage flux suppression structure is formed at the stepped hole 242. The distance between the stepped hole 242 and the outer peripheral surface of the rotor core 21 is small, forming a second thin-walled structure 252 between them. Magnetic flux tends to concentrate at this thin-walled structure 252, and during operation of the permanent magnet motor 100, to reduce magnetic leakage, this structure is often made thinner, resulting in saturation of the magnetic flux at this location. This causes the armature reaction demagnetizing magnetic field to pass through the end of the second permanent magnet 262. Therefore, the stepped hole 242 is designed to reduce the magnetic flux passing through the second permanent magnet 262, thus improving demagnetization resistance.

[0079] In addition, the stepped hole 242 makes it easier for the magnetic flux generated by the stator 10 to link to the rotor 20, thereby improving the magnetic field utilization rate of the stator 10 and increasing efficiency. Understandably, the magnetic barrier hole 24 at the end of the second mounting hole 232 can also be set in other shapes, such as triangular, arc-shaped, trapezoidal, etc.

[0080] In one embodiment, the distance between each magnetic barrier hole 24 and the outer peripheral surface of the rotor core 21 is greater than or equal to the thickness of the rotor lamination, so as to ensure the structural strength of the rotor core 21.

[0081] In one embodiment, the diameter of the central hole 27 of the rotor core 21 is D1, the outer diameter of the rotor core 21 is D2, and the minimum distance between the flow hole 2321 and the central hole 27 is R1, then R1≤(D2-D1) / 2. This ensures good structural strength of the rotor core 21 and allows for a larger area of ​​the flow hole 2321, improving gas-liquid flow capacity.

[0082] In one embodiment, the minimum distance between the first mounting hole 231 and the center hole 27 is R2, and the minimum distance between the second permanent magnet 262 and the center hole 27 is R3, then R1≤R3≤R2. That is, the minimum distance R1 between the flow hole 2321 and the center hole 27 is less than or equal to the minimum distance R3 between the second permanent magnet 262 and the center hole 27, and the minimum distance R3 between the second permanent magnet 262 and the center hole 27 is less than or equal to the minimum distance R2 between the first mounting hole 231 and the center hole 27, so as to ensure good structural strength of the rotor core 21, and the area of ​​the flow hole 2321 can be made larger to improve the gas-liquid flow capacity.

[0083] In one embodiment, the width of the stepped hole 242 is W3, and the width of the second mounting hole 232 near the outer peripheral surface of the rotor core 21 is W2. By reducing W3, the magnetic flux from the stator 10 can be increased. Increasing W3 can also suppress the short-circuit leakage magnetic flux of the permanent magnet. In other words, the relationship between W3 and W2 directly affects the magnetic flux, anti-demagnetization ability and leakage flux.

[0084] In one embodiment, the width W3 of the stepped hole 242 is greater than or equal to half the width W2 of the second mounting hole 232 near the outer peripheral surface of the rotor core 21. That is, W3 ≥ 0.5 * W2, which can increase the magnetic flux from the stator 10, improve the structural strength, and ensure better anti-demagnetization capability.

[0085] In one embodiment, the width W3 of the stepped hole 242 is greater than or equal to half the width W2 of the second mounting hole 232 near the outer peripheral surface of the rotor core 21, and the width W3 of the stepped hole 242 is less than or equal to 0.9 times the width W2 of the second mounting hole 232 near the outer peripheral surface of the rotor core 21, i.e., 0.5*W2≤W3≤0.9*W2. This allows the relationship between W3 and W2 to directly affect the magnetic flux, demagnetization resistance, and leakage flux balance, thereby ensuring the magnetic flux of the stator 10, good structural strength, high demagnetization resistance, and low leakage flux.

[0086] In one embodiment, see Figures 1 to 3 The minimum distance from the stepped hole 242 to the outer peripheral surface of the rotor core 21 is L1, which means the width of the second thin-walled structure 252 is L1. The minimum distance from the end of the second mounting hole 232 near the outer peripheral surface of the rotor core 21 to the outer peripheral surface of the rotor core 21 is L2. Therefore, L2≥2*L1. On the one hand, it can ensure the structural strength at the second thin-walled structure 252, and on the other hand, it can better reduce leakage flux, increase the magnetic flux from the stator 10, and thus improve the torque.

[0087] In one embodiment, the width L1 of the second thin-walled structure 252 is greater than or equal to the thickness T of the rotor lamination, i.e., L1≥T, which can ensure the structural strength of the second thin-walled structure 252.

[0088] In one embodiment, when the width of the second thin-walled structure 252 is L1 and the distance from one end of the second mounting hole 232 near the outer peripheral surface of the rotor core 21 to the outer peripheral surface of the rotor core 21 is L2, the width of the stepped hole 242 along the radial direction of the rotor core 21 is L2-L1. The stepped hole 242 affects the output torque and torque pulsation of the permanent magnet motor 100. L2-L1=0.3*W2, that is, when the width of the stepped hole 242 along the radial direction of the rotor core 21 is equal to 0.3 times the width W2 of the second mounting hole 232 near the outer peripheral surface of the rotor core 21, the per-unit value of the output torque of the permanent magnet motor 100 is the largest, and the per-unit value of the torque pulsation is the smallest.

[0089] In one embodiment, the minimum distance W1 between two adjacent second mounting holes 232 of two adjacent magnetic pole units 22 is less than or equal to the width T1 of the opening of the stator slot 113, and the width W2 of the second mounting hole 232 near the outer peripheral surface of the rotor core 21 is less than or equal to the distance T2 between two adjacent stator teeth 112. The distance T2 between two stator teeth 112 refers to the minimum distance between the center lines 1121 of the two stator teeth 112, so as to ensure good structural strength of the rotor core 21, increase the magnetic flux from the stator 10, and thus improve the torque.

[0090] In one embodiment, considering the influence of magnetic leakage, and to reduce the influence of the demagnetizing current on the permanent magnet when the permanent magnet motor 100 outputs magnetic reluctance torque, a width can be reserved between the first permanent magnet 261 and the first mounting hole 231, and a width can be reserved between the second permanent magnet 262 and the second mounting hole 232. That is, there is a gap between the first permanent magnet 261 and the first mounting hole 231, and there is a gap between the second permanent magnet 262 and the second mounting hole 232.

[0091] In one embodiment, a boss may be provided in the first mounting hole 231 to position the first permanent magnet 261. Understandably, the first permanent magnet 261 may also be positioned and installed in the first mounting hole 231 by filling the gap of the first mounting hole 231 with resin, inserting a non-magnetic pin, or other means.

[0092] In one embodiment, a boss may be provided in the second mounting hole 232 to position the second permanent magnet 262. Understandably, the second permanent magnet 262 may also be positioned and installed in the second mounting hole 232 by filling the gap in the second mounting hole 232 with resin, inserting a non-magnetic pin, or other methods.

[0093] In this embodiment, the magnetic field lines generated by the stator 10 are approximately elliptical in the q-axis direction, and the magnetic flux density generated solely by the stator 10 is distributed in the air gap in a near-sine wave pattern. The first permanent magnet 261 and the second permanent magnet 262 are respectively installed in the first mounting hole 231 and the second mounting hole 232 in the rotor core 21. The arrangement of the first mounting hole 231 and the second mounting hole 232 affects the q-axis magnetic circuit. To minimize the influence of the first mounting hole 231 and the second mounting hole 232 on the q-axis magnetic circuit, the arrangement of the first mounting hole 231 and the second mounting hole 232 is designed as follows: Figure 2 The structure of the first mounting hole 231 is arc-shaped or approximately arc-shaped. The arc shape facilitates the smooth flow of magnetic lines of force on the inner side. The ends of the first mounting hole 231 and the ends of the second mounting hole 232 near the outer peripheral surface of the rotor core 21 are approximately perpendicular to the outer peripheral surface of the rotor core 21. The second mounting hole 232 is located near the adjacent magnetic pole unit 22. To better perpendicularize to the outer peripheral surface of the rotor core 21, it is designed as a rectangular structure. At the same time, in order to reduce the saturation distribution of the q-axis magnetic circuit on the outer periphery of the rotor 20, the end of the second mounting hole 232, combined with the mounting and fixing position of the second permanent magnet 262, is designed as a stepped hole 242. This makes the magnetic flux distribution at the air gap of the permanent magnet motor 100 close to a sine wave, reducing high-order harmonics in the magnetic flux distribution, since high-order harmonic components do not contribute to torque output. In addition, it can also suppress the magnetic flux deformation generated by the first permanent magnet 261 and the second permanent magnet 262 along the d-axis, as well as suppress the deformation of the magnetic flux (q-axis flux) generated by the stator 10.

[0094] Since the magnetic flux waveform of the rotor 20 with a single magnetic pole of the permanent magnet 26 formed by the first permanent magnet 261 and the second permanent magnet 262 is a synthesis of the magnetic flux of the two second permanent magnets 262 and the first permanent magnet 261, it contains a large number of high-order harmonic components. Moreover, when the permanent magnet motor 100 is working, the magnetomotive force generated by the stator winding 10 and the armature reaction of the magnetic field formed by the permanent magnet 26 of the rotor 20 have a certain angle. Among them, the armature magnetic weakening reaction is dominant during high-speed operation. By predicting the magnetic field direction of the permanent magnet 26 of the rotor 20 and the angle of the magnetic field of the stator winding 10, it is possible to predict the position of the magnet mounting hole 23 in the rotor core 21 and the air gap relative to the stator teeth 112 at a certain moment during the high-speed operation of the rotor 20 of the permanent magnet motor 100. The working magnetic field can form a smooth magnetic circuit closed loop through the magnetic conduction channel of the stator teeth 112 and the remaining part of the rotor 20 after removing the magnet mounting hole 23. Furthermore, by adjusting the outer circumference of the rotor 20, the magnetic resistance of the gap between the rotor 20 and the stator 10 can be changed, so that the magnetic flux waveform is close to the ideal sine wave, thereby reducing the high-order harmonic components of the magnetic flux density of the stator 10 and reducing the proportion of harmonic content of the back EMF of the permanent magnet motor 100.

[0095] Please see Figure 1 , Figures 4 to 6For ease of description, a planar unfolded analysis and comparison of the stator 10 and rotor 20 of the permanent magnet motor 100 is performed. Magnetic barrier holes 24 form rotor magnetic barriers 28 on the unfolded surface of the rotor 20. The magnetic barrier holes 24 at the end of the first mounting hole 231 correspond to the first rotor magnetic barrier 281 on the unfolded surface of the rotor 20, and the magnetic barrier holes 24 at the end of the second mounting hole 232 correspond to the second rotor magnetic barrier 282 on the unfolded surface of the rotor 20. The torque of the permanent magnet motor 100 is modulated by the controller to produce the resultant force of the permanent magnet torque and the reluctance torque. The first magnetic guide position 211, the second magnetic guide position 212, and the third magnetic guide position 213 on the rotor core 21 constitute the magnetic guide part 210 of the rotor 20. During operation, the permanent magnet motor 100 is subjected to armature reaction, and the electrical angle of the armature reaction is predictable. By predicting the deviation angle, the positions of the stator laminations and rotor laminations are translated, and the relative positions of the slot opening 1131 of the stator slot 113 and the rotor magnetic barrier 28 are observed during the translation. The positions of the slot opening 1131 of the stator slot 113 and the rotor magnetic barrier 28 are offset by the operating angle. During the movement, it was found that when the slot opening 1131 of the stator slot 113 is directly aligned with the second layer magnetic position 212 on the rotor 20, the magnetic field waveform of the permanent magnet motor 100 is prone to distortion, and the back EMF harmonic content of the permanent magnet motor 100 is high. When the slot opening 1131 of the stator slot 113 is not directly aligned with the second layer magnetic position 212 on the rotor 20, that is, when the slot opening 1131 of the stator slot 113 is offset from the second layer magnetic position 212 on the rotor 20, the magnetic field waveform distortion of the permanent magnet motor 100 is smaller. Therefore, by adjusting the outer surface of the rotor 20, the air gap magnetic field waveform can be made as sinusoidal as possible. Furthermore, when the slot opening 1131 of stator slot 113 is directly aligned with the third magnetic position 213 on rotor 20, the magnetic field waveform of permanent magnet motor 100 is prone to distortion, resulting in high back EMF harmonic content. When the slot opening 1131 of stator slot 113 is not directly aligned with the third magnetic position 213 on rotor 20, i.e., when the slot opening 1131 of stator slot 113 is misaligned with the third magnetic position 213 on rotor 20, the magnetic field waveform distortion of permanent magnet motor 100 is smaller. Therefore, by adjusting the outer circumference of rotor 20, the air gap magnetic field waveform can be made as sinusoidal as possible. Please refer to [link / reference]. Figure 1 and Figure 7 , Figure 7 Bar A represents the back EMF harmonic component when the slot opening 1131 of stator slot 113 is directly aligned with the third magnetic guide position 213. Bar B represents the back EMF harmonic component when the slot opening 1131 of stator slot 113 is misaligned with the third magnetic guide position 213. The vertical axis in the figure represents the magnitude of the harmonic components. As can be seen from the figure, when the slot opening 1131 of stator slot 113 is misaligned with the third magnetic guide position 213, the proportion of higher harmonics in the back EMF harmonics decreases significantly, thereby reducing the magnetic field waveform distortion of the permanent magnet motor 100.

[0096] Please see Figure 1 and Figure 8 , Figure 8In the diagram, bar C represents the output torque when the slot opening 1131 of stator slot 113 is directly aligned with the third magnetic guide position 213, and bar E represents the output torque when the slot opening 1131 of stator slot 113 is misaligned with the third magnetic guide position 213, all while maintaining the same output current. As shown in the diagram, when the output current is the same, the permanent magnet motor 100 outputs a greater torque when the slot opening 1131 of stator slot 113 is misaligned with the third magnetic guide position 213.

[0097] The permanent magnet motor 100 of this application embodiment can better combine reluctance torque and permanent magnet torque to output greater torque, reduce higher harmonics, reduce magnetic field waveform distortion, suppress torque pulsation, improve demagnetization resistance, reduce the amount of magnets used, achieve a balance between performance and price, and provide high-efficiency output and high-frequency high-output torque.

[0098] This application also provides a compressor, including a housing, in which a permanent magnet motor as described in the above embodiments is installed. This compressor, using the permanent magnet motor of the above embodiments, has the beneficial effects of the aforementioned permanent magnet motor, which will not be elaborated further here. This compressor can be an air conditioner compressor, a refrigerator compressor, etc.

[0099] This application also provides a household appliance, including a permanent magnet motor as described in the above embodiments. This household appliance, using the permanent magnet motor of the above embodiments, has the beneficial effects of the aforementioned permanent magnet motor, which will not be repeated here. This household appliance can be an air conditioner, refrigerator, microwave oven, fan, vacuum cleaner, etc.

[0100] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A permanent magnet motor, comprising a stator and a rotor, wherein the stator includes a stator core, the stator core including a plurality of stator teeth and a stator yoke supporting the plurality of stator teeth, the plurality of stator teeth forming a stator inner hole, stator slots being formed between adjacent stator teeth, and windings being wound on the stator teeth; the rotor is rotatably mounted in the stator inner hole, the rotor including a rotor core, the rotor core having a plurality of magnetic pole units, the plurality of magnetic pole units being uniformly distributed along the circumference of the rotor core, characterized in that, Each of the magnetic pole units includes multiple layers of magnet mounting holes arranged radially along the rotor core. Each magnet mounting hole contains a permanent magnet. The end of each magnet mounting hole is located adjacent to the outer peripheral surface of the rotor core. The magnetic field generated by the stator has an electrical angle with the magnetic field of the adjacent magnetic pole unit. The electrical angle ranges from 20° to 70°.

2. The permanent magnet motor as described in claim 1, characterized in that: Each of the magnet mounting holes has a magnetic barrier hole protruding from its end toward the outer peripheral surface of the rotor core, and the width of each magnetic barrier hole is less than or equal to the width of the corresponding magnet mounting hole.

3. The permanent magnet motor as described in claim 2, characterized in that: The multi-layer magnet mounting holes include a first mounting hole and at least one layer of second mounting holes arranged radially along the rotor core. The two ends of the first mounting hole are bent toward the outer peripheral surface of the rotor core. The first mounting hole is symmetrically arranged about one radial surface of the rotor core. There are two second mounting holes in each layer. The first mounting hole is located between the two second mounting holes in each layer. The permanent magnet includes a first permanent magnet disposed in the first mounting hole and a second permanent magnet disposed in the second mounting hole.

4. The permanent magnet motor as described in claim 3, characterized in that: A first magnetic guide position is formed between the magnetic barrier holes at both ends of the first mounting hole, a second magnetic guide position is formed between the two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit, and a third magnetic guide position is formed between the two adjacent magnetic barrier holes of two adjacent magnetic pole units. The width of the second magnetic guide position is less than or equal to the slot width of the stator slot.

5. The permanent magnet motor as described in claim 3, characterized in that: A first magnetic guide position is formed between the magnetic barrier holes at both ends of the first mounting hole. A second magnetic guide position is formed between the two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit. A third magnetic guide position is formed between the two adjacent magnetic barrier holes of two adjacent magnetic pole units. The width of the third magnetic guide position is less than or equal to the slot width of the stator slot.

6. The permanent magnet motor as described in claim 3, characterized in that: A first magnetic conductive position is formed between the magnetic barrier holes at both ends of the first mounting hole, a second magnetic conductive position is formed between the two magnetic barrier holes corresponding to the magnet mounting holes in adjacent layers of the magnetic pole unit, and a third magnetic conductive position is formed between the two adjacent magnetic barrier holes of two adjacent magnetic pole units; the slot opening of the stator slot is offset from the second magnetic conductive position, and the slot opening of the stator slot is offset from the third magnetic conductive position.

7. The permanent magnet motor according to any one of claims 3-6, characterized in that: The magnet mounting holes in each layer are bent into a U-shape, and the two ends of the magnet mounting holes in each layer extend toward the outer peripheral surface of the rotor core. The two ends of the second mounting hole are respectively provided with the second permanent magnet, and a flow hole is formed in the middle of the second mounting hole.

8. The permanent magnet motor as described in claim 7, characterized in that: The minimum distance between the first mounting hole and the second mounting hole is less than or equal to the width of the second mounting hole.

9. The permanent magnet motor as described in claim 7, characterized in that: The first mounting hole is arc-shaped, and the two ends of the second mounting hole, corresponding to the areas where the second permanent magnet is installed, are both rectangular.

10. The permanent magnet motor as described in claim 7, characterized in that: The distance between the first mounting hole and the second mounting hole is gradually reduced in the direction along the radial direction of the rotor core toward the outer peripheral surface of the rotor core.

11. The permanent magnet motor according to any one of claims 3-6, characterized in that: The magnetic barrier hole at the end of the first mounting hole is a shrinkage hole, and the width of the shrinkage hole gradually decreases along the radial direction of the rotor core from the first mounting hole to the outer peripheral surface of the rotor core. The magnetic barrier hole at the end of the second mounting hole is a stepped hole, and the width of the stepped hole is smaller than the width of the second mounting hole.

12. The permanent magnet motor according to any one of claims 2-6, characterized in that: The rotor core is constructed by stacking rotor laminations, and the distance between each magnetic barrier hole and the outer peripheral surface of the rotor core is greater than or equal to the thickness of any rotor lamination.

13. A compressor, comprising a housing, characterized in that: The housing is equipped with a permanent magnet motor as described in any one of claims 1-12.

14. A household appliance, characterized in that: Including the permanent magnet motor as described in any one of claims 1-12.

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