Permanent magnet synchronous motor

Abstract

The invention discloses a permanent magnet synchronous motor. The permanent magnet synchronous motor comprises a rotating shaft, a first stator, a rotor, a second stator and a plurality of permanent magnets, the rotor is located between the first stator and the second stator and is coaxially arranged with the rotating shaft, and the first stator and the second stator are coaxially arranged and are fixed with the rotating shaft; the first stator comprises a plurality of first stator slots which are arranged at intervals along the circumferential direction, the first stator slots comprise first windings, the second stator comprises a plurality of second stator slots which are arranged at intervals along the circumferential direction, and the second stator slots comprise second windings; the rotor comprises a plurality of rotor cores, the rotor cores are arranged at intervals in the circumferential direction, the permanent magnets are tangentially placed on the rotor cores and are of tangential magnetic circuit structures, the polarities of the adjacent permanent magnets are the same, the rotor is arranged between the first stator and the second stator, and the permanent magnets of the tangential magnetic circuit structures are tangentially placed on the rotor cores. The motor structure is optimized, the torque density of the motor is improved, the flux leakage amount is reduced, and the performance of the motor is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a permanent magnet synchronous motor. Background Art

[0002] The high energy efficiency level of the permanent magnet synchronous motor gives it significant advantages in energy utilization, enabling effective reduction of energy consumption and conforming to the current global development trend of energy conservation and emission reduction. Its wide operating range and high overload capacity allow the compressor to operate stably and efficiently under different working conditions. However, the existing permanent magnet synchronous motors do not optimize the distribution of the air-gap magnetic field, resulting in certain harmonic losses, affecting the operating stability of the motor, and posing challenges to the optimization of the motor. Summary of the Invention

[0003] The present invention provides a permanent magnet synchronous motor, which can effectively improve magnetic leakage, reduce harmonic losses, and optimize the performance of the permanent magnet synchronous motor.

[0004] In a first aspect, the present invention provides a permanent magnet synchronous motor, which includes: a rotating shaft, a first stator, a rotor, a second stator, and a plurality of permanent magnets. The rotor is located between the first stator and the second stator and is coaxially arranged with the rotating shaft. The first stator and the second stator are coaxially arranged and fixed to the rotating shaft;

[0005] The first stator includes a plurality of first stator slots arranged at intervals in the circumferential direction. The first stator slots include first windings. The second stator includes a plurality of second stator slots arranged at intervals in the circumferential direction. The second stator slots include second windings;

[0006] The rotor includes a plurality of rotor cores, which are arranged at intervals in the circumferential direction. The permanent magnets are tangentially placed on the rotor cores and the permanent magnets have a tangential magnetic circuit structure. The polarities of adjacent permanent magnets are the same.

[0007] Optionally, the first stator and the rotor are spaced apart to form a first air gap, and the second stator and the rotor are spaced apart to form a second air gap.

[0008] Optionally, there is no magnetic conduction between adjacent two rotor cores.

[0009] Optionally, the slot positions of the first stator slots and the second stator slots are aligned.

[0010] Optionally, when the rotor rotates, the phase splitting phases of the first windings and the phase splitting phases of the second windings differ by 180 electrical degrees.

[0011] Optionally, the first windings and the second windings are phase split according to the slot electromotive force star diagram.

[0012] Optionally, the rotor core is provided with two first convex keys and two second convex keys that are symmetrically arranged. The two first convex keys are located on the side of the rotor core close to the first stator, and the two second convex keys are located on the side of the rotor core close to the second stator.

[0013] Optionally, the first winding and the second winding are concentrated windings or distributed windings.

[0014] Optionally, the first stator, the second stator, and the rotor are all formed by stacking silicon steel sheets.

[0015] Optionally, the materials of the first stator and the second stator are silicon steel sheets or amorphous alloys.

[0016] The technical solution of the embodiment of the present invention provides a permanent magnet synchronous motor, which includes: a rotating shaft, a first stator, a rotor, a second stator, and a plurality of permanent magnets. The rotor is located between the first stator and the second stator and is coaxially arranged with the rotating shaft. The first stator and the second stator are coaxially arranged and fixed to the rotating shaft. The first stator includes a plurality of first stator slots arranged at intervals in the circumferential direction. The first stator slots include first windings. The second stator includes a plurality of second stator slots arranged at intervals in the circumferential direction. The second stator slots include second windings. The rotor includes a plurality of rotor cores, which are arranged at intervals in the circumferential direction. The permanent magnets are tangentially placed on the rotor cores and the permanent magnets are of a tangential magnetic circuit structure. The polarities of adjacent permanent magnets are the same. By arranging the rotor between the first stator and the second stator in the permanent magnet synchronous motor, the space utilization rate is improved. The permanent magnets of the tangential magnetic circuit structure are tangentially placed on the rotor cores, and the polarities of adjacent permanent magnets are the same, which improves the torque density of the electrode, reduces the magnetic leakage, and ensures the performance of the motor.

[0017] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of a permanent magnet synchronous motor provided by an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of flux switching of a permanent magnet synchronous motor provided by an embodiment of the present invention;

[0021] Figure 3 Another flux-switching schematic diagram of the permanent magnet synchronous motor provided by the embodiment of the present invention;

[0022] Figure 4 Another flux-switching schematic diagram of the permanent magnet synchronous motor provided by the embodiment of the present invention;

[0023] Figure 5 Another flux-switching schematic diagram of the permanent magnet synchronous motor provided by the embodiment of the present invention;

[0024] Figure 6 Back electromotive force waveform diagram of a first winding provided by the embodiment of the present invention;

[0025] Figure 7 Back electromotive force waveform diagram of a second winding provided by the embodiment of the present invention;

[0026] Figure 8 Magnetic field line schematic diagram of a permanent magnet synchronous motor provided by the embodiment of the present invention;

[0027] Figure 9 Another structural schematic diagram of the permanent magnet synchronous motor provided by the embodiment of the present invention;

[0028] Figure 10 Phase-splitting diagram of a first winding provided by the embodiment of the present invention;

[0029] Figure 11 Phase-splitting diagram of a second winding provided by the embodiment of the present invention.

[0030] In the figure:

[0031] 101, rotating shaft; 102, first stator; 1021, first stator slot; 1022, first winding; 103, rotor; 1031, rotor core; 104, second stator; 1041, second stator slot; 1042, second winding; 105, permanent magnet; 106, first key; 107, second key. Detailed implementation manners

[0032] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0034] Figure 1 The following is a schematic structural diagram of a permanent magnet synchronous motor provided by an embodiment of the present invention, as Figure 1 shown. The permanent magnet synchronous motor includes: a rotating shaft 101, a first stator 102, a rotor 103, a second stator 104 and a plurality of permanent magnets 105. The rotor 103 is located between the first stator 102 and the second stator 104 and is coaxially arranged with the rotating shaft 101. The first stator 102 and the second stator 104 are coaxially arranged and fixed to the rotating shaft 101. The first stator 102 includes a plurality of first stator slots 1021 arranged at intervals in the circumferential direction. The first stator slots 1021 include first windings 1022. The second stator 104 includes a plurality of second stator slots 1041 arranged at intervals in the circumferential direction. The second stator slots 1041 include second windings 1042. The rotor 103 includes a plurality of rotor cores 1031. The rotor cores 1031 are arranged at intervals in the circumferential direction. The permanent magnets 105 are tangentially placed on the rotor cores 1031 and the permanent magnets 105 have a tangential magnetic circuit structure. The polarities of adjacent permanent magnets 105 are the same.

[0035] Among them, the permanent magnet synchronous motor is provided with a rotating shaft 101, a first stator 102, a rotor 103, a second stator 104 and a plurality of permanent magnets 105. The rotor 103 is located between the first stator 102 and the second stator 104 and is coaxially arranged with the rotating shaft 101. The first stator 102 and the second stator 104 are coaxially arranged and fixed to the rotating shaft 101, that is, the first stator 102, the rotor 103 and the second stator 104 are arranged in sequence from the inside to the outside along the radial direction of the rotating shaft 101. The first stator 102 includes a plurality of first stator slots 1021 arranged at intervals in the circumferential direction. The first stator slots 1021 include first windings 1022. The second stator 104 includes a plurality of second stator slots 1041 arranged at intervals in the circumferential direction. The second stator slots 1041 include second windings 1042. The number of the first stator slots 1021 is the same as the number of the second stator slots 1041. The first windings 1022 and the second windings 1042 can be independently controlled to ensure the driving force on the rotor 103 and improve the torque output. The rotor 103 includes a plurality of rotor cores 1031. The rotor cores 1031 are arranged at intervals in the circumferential direction to form a spoke-type rotor 103 structure. The permanent magnets 105 are tangentially placed on the rotor cores 1031. The permanent magnets 105 can be selected as permanent magnetic components. When a plurality of permanent magnets 105 are arranged, they are arranged at equal intervals along the circumferential direction of the rotor 103. The permanent magnets 105 are of a tangential magnetic circuit structure, and the magnetic poles of the permanent magnets 105 face the first stator 102 and the second stator 104 respectively. By arranging the permanent magnets 105 in a tangential magnetic circuit structure, the occupied space of the permanent magnets 105 becomes smaller, so that more permanent magnets 105 can be arranged in a limited space to meet the performance requirements of multi-pole number and low-speed high-torque of the double-stator permanent magnet synchronous motor. The polarities of adjacent permanent magnets 105 are the same, that is, the arrangement modes of the permanent magnets 105 are the same, which reduces the difficulty of arranging the permanent magnets 105. The permanent magnets 105 are arranged with the same polarity, and the magnetic field directions of adjacent permanent magnets 105 are the same, reducing the magnetic leakage path between the magnetic poles, so that more magnetic fluxes are concentrated to enter the first stator 102 or the second stator 104 through the air gap, thereby improving the air-gap magnetic density and torque density. After three-phase alternating current is introduced into the first windings 1022 and the second windings 1042, a rotating magnetic field will be generated. When the rotating magnetic field interacts with the like-pole magnetic field of the permanent magnets 105 on the rotor 103, an attractive force is generated when the rotating magnetic field is in the same direction as the magnetic field direction of the permanent magnets 105 on the rotor 103; a repulsive force is generated when the rotating magnetic field is in the opposite direction to the magnetic field direction of the permanent magnets 105 on the rotor 103. By controlling the phase and amplitude of the stator current, the permanent magnets 105 on the rotor 103 can always be subjected to a tangential electromagnetic force, so as to rotate continuously.

[0036] Figure 2 The following is a schematic diagram of flux switching of a permanent magnet synchronous motor provided by an embodiment of the present invention. As Figure 2 shown, when the rotor 103 is located as Figure 2At the initial position shown. At this time, the rotor teeth B2 coincide with the armature coils A1 of the first stator 102 and the armature coils A2 of the second stator 104. The permanent magnetic flux linkage generated by the permanent magnet 105 passes through the armature coils A1 and A2, enters the rotor teeth B2 through the air gap, and links with the armature coils A1 and A2. At this time, the amplitude of the permanent magnetic flux linkage in the armature coils A1 and A2 is the maximum value of the positive polarity.

[0037] Figure 3 Another flux-switching schematic diagram of a permanent magnet synchronous motor provided by an embodiment of the present invention is shown in Figure 3 As shown, when the rotor 103 rotates to the position shown in Figure 3, the permanent magnet 105 on the rotor 103 is exactly opposite to the armature coils A1 and A2, and the effective magnetic flux linked in the armature coils A1 and A2 is 0.

[0038] Figure 4 Another flux-switching schematic diagram of a permanent magnet synchronous motor provided by an embodiment of the present invention is shown in Figure 4 As shown, when the rotor 103 continues to rotate to the position shown in Figure 4 As shown, the rotor teeth B1 coincide with the armature coils A1 and A2. The permanent magnetic flux linkage generated by the permanent magnet 105 passes through the air gap from the rotor teeth B1, enters the stator armature teeth, and links with the armature coils A1 and A2. At this time, the amplitude of the permanent magnetic flux linkage in the armature coils A1 and A2 is the maximum value of the positive polarity.

[0039] Figure 5 Another flux-switching schematic diagram of a permanent magnet synchronous motor provided by an embodiment of the present invention is shown in Figure 5 As shown, when the rotor 103 rotates to the position shown in Figure 5 As shown, the air gap between the adjacent rotor cores 1031 is exactly opposite to the armature coils A1 and A2, and the effective magnetic flux linked in the armature coils A1 and A2 is 0.

[0040] Figure 6 An electromotive force waveform diagram of a first winding provided by an embodiment of the present invention is shown in Figure 6 As shown, during the rotation of the rotor 103, the first winding 1022 of the first stator 102 generates an electromotive force waveform diagram distributed in a sine shape. The first winding 1022 includes a phase A winding, a phase B winding, and a phase C winding, that is, the electromotive force waveform diagram includes the phase A winding electromotive force 11, the phase B winding electromotive force 12, and the phase C winding electromotive force 13.

[0041] Figure 7 An electromotive force waveform diagram of a second winding provided by an embodiment of the present invention is shown in Figure 7As shown, during the rotation of the rotor 103, the second winding 1042 of the second stator 104 generates a back electromotive force waveform diagram with a sinusoidal distribution. The second winding 1042 includes an A-phase winding, a B-phase winding, and a C-phase winding, that is, the back electromotive force waveform diagram includes the back electromotive force 21 of the A-phase winding, the back electromotive force 22 of the B-phase winding, and the back electromotive force 23 of the C-phase winding.

[0042] An embodiment of the present invention provides a permanent magnet synchronous motor, which includes: a rotating shaft, a first stator, a rotor, a second stator, and a plurality of permanent magnets. The rotor is located between the first stator and the second stator and is coaxially arranged with the rotating shaft. The first stator and the second stator are coaxially arranged and fixed to the rotating shaft. The first stator includes a plurality of first stator slots arranged at intervals in the circumferential direction. The first stator slots include first windings. The second stator includes a plurality of second stator slots arranged at intervals in the circumferential direction. The second stator slots include second windings. The rotor includes a plurality of rotor cores, and the rotor cores are arranged at intervals in the circumferential direction. The permanent magnets are tangentially placed on the rotor cores and the permanent magnets have a tangential magnetic circuit structure. The polarities of adjacent permanent magnets are the same. By arranging the rotor between the first stator and the second stator in the permanent magnet synchronous motor, the space utilization rate is improved. The permanent magnets with a tangential magnetic circuit structure are tangentially placed on the rotor cores, and the polarities of adjacent permanent magnets are the same, which improves the torque density of the electrode, reduces the magnetic leakage, and ensures the motor performance.

[0043] Optionally, continue to refer to Figure 1 , a first air gap is formed by arranging the first stator 102 and the rotor 103 at intervals, and a second air gap is formed by arranging the second stator 104 and the rotor 103 at intervals.

[0044] Among them, the air gap is an important part of the magnetic circuit. The permanent magnet 105 needs to form a closed magnetic circuit through the air gap. Generally, the larger the air gap, the smaller the inductance, which is beneficial to weak magnetic speed regulation, but will reduce the torque density; the smaller the air gap, the larger the inductance, which may limit the high-speed performance. A first air gap is formed by arranging the first stator 102 and the rotor 103 at intervals, and a second air gap is formed by arranging the second stator 104 and the rotor 103 at intervals, so that a double air gap structure is formed between the first stator 102 and the rotor 103, and between the second stator 104 and the rotor 103, optimizing the magnetic leakage of the permanent magnet 105 and the waveform of the resign, and ensuring the operation effect of the motor. The air gap length of the first air gap formed by arranging the first stator 102 and the rotor 103 at intervals and the air gap length of the second air gap formed by arranging the second stator 104 and the rotor 103 at intervals can be selected according to actual design requirements, and the embodiments of the present invention do not make specific limitations.

[0045] Optionally, Figure 8 is a schematic diagram of the magnetic force lines of a permanent magnet synchronous motor provided by an embodiment of the present invention. As Figure 1 and Figure 8As shown, there is no magnetic conduction between adjacent rotor cores 1031. The adjacent rotor cores 1031 are segmented and there is no magnetic conduction between them. Non-magnetic materials can be used for isolation or an air gap can be used for isolation. The non-magnetic isolation makes the magnetic field of each rotor core 1031 more concentrated in its own pole direction, reduces the magnetic leakage between adjacent poles, optimizes the magnetic field, enhances the air-gap magnetic density, and improves the torque density and the utilization rate of the permanent magnet 105.

[0046] Optionally, Figure 9 is a schematic structural diagram of another permanent magnet synchronous motor provided by an embodiment of the present invention. As Figure 1 and Figure 9 shown, the slot positions of the first stator slots 1021 and the second stator slots 1041 are aligned. By setting the slot positions of the first stator slots 1021 and the second stator slots 1041 to be aligned, the magnetic field generated by the permanent magnet 105 can penetrate the first stator 102 and the second stator 104 simultaneously. The aligned first stator slots 1021 and second stator slots 1041 ensure that the magnetic flux path is symmetric, avoid magnetic circuit distortion, improve the utilization rate of the permanent magnet 105, and increase the torque density. The first stator slots 1021 and the second stator slots 1041 can share a mold or be symmetrically processed to ensure process consistency and reduce production costs and difficulties.

[0047] Optionally, Figure 10 is a phase-splitting diagram of a first winding provided by an embodiment of the present invention. Figure 11 is a phase-splitting diagram of a second winding provided by an embodiment of the present invention. As Figure 1 、 Figure 10 and Figure 11 shown, when the rotor 103 rotates, the phase-splitting phases of the first winding 1022 and the second winding 1042 differ by 180 electrical degrees.

[0048] Among them, setting the phase-splitting phases of the first winding 1022 and the second winding 1042 to differ by 180 electrical degrees makes the back electromotive force phases generated in the first winding 1022 and the second winding 1042 the same when the rotor 103 rotates, that is, the back electromotive force phases generated by the permanent magnet 105 in the first winding 1022 and the second winding 1042 are the same. The reverse-phase windings can cancel the low-order space harmonics, make the air-gap magnetic field closer to a sine distribution, thereby reducing the torque ripple, improving the output smoothness, and ensuring the performance of the motor. By coordinating the phase difference between the first winding 1022 and the second winding 1042, the driving force on the rotor 103 can be increased and the torque output can be improved.

[0049] Optionally, continuing to refer to Figure 1 、 Figure 10 and Figure 11 , the first winding 1022 and the second winding 1042 are phase-split according to the slot electromotive force star diagram.

[0050] Among them, assuming that the air-gap magnetic density is distributed sinusoidally around the circumference, when the rotor 103 rotates counterclockwise, the induced electromotive force of the conductors in each stator slot will also change sinusoidally with time. When the electromotive forces of the conductors in each slot on the armature that change sinusoidally are represented by vectors respectively, these vectors form a radiation star diagram. When phase-splitting the first winding 1022, phase-splitting can be performed according to the slot electromotive force star diagram, and the specific phase-splitting schematic diagram is as shown in Figure 10 shown. When phase-splitting the second winding 1042, phase-splitting can be performed according to the slot electromotive force star diagram, and the specific phase-splitting schematic diagram is as shown in Figure 11 shown.

[0051] Optionally, continuing to refer to Figure 1 and Figure 9 , the rotor core 1031 is provided with two first convex keys 106 and two second convex keys 107 that are symmetrically arranged. The two first convex keys 106 are located on the side of the rotor core 1031 close to the first stator 102, and the two second convex keys 107 are located on the side of the rotor core 1031 close to the second stator 104.

[0052] Among them, two first convex keys 106 that are symmetrically arranged are provided on the side of the rotor core 1031 close to the first stator 102 and two second convex keys 107 that are symmetrically arranged are provided on the side of the rotor core 1031 close to the second stator 104, that is, a rotor core 1031 is provided with four convex keys, so that the permanent magnet 105 arranged on the rotor core 1031 can be fixed by the four convex keys, avoiding the permanent magnet 105 being thrown out during high-speed operation, and can also effectively improve the mechanical strength of the rotor core 1031 and ensure the performance of the motor.

[0053] Optionally, continuing to refer to Figure 1 , the first winding 1022 and the second winding 1042 are concentrated windings or distributed windings.

[0054] Among them, the electromagnetic coils of the concentrated winding are only wound on one tooth of the stator, without the behavior of spanning teeth. Each group of electromagnetic coils is independent and will not intersect. Its advantage is that the ineffective end of the electromagnetic coil is very short, which can reduce the wire usage, and can also reduce the resistance of the electromagnetic coil, reduce copper loss, reduce manufacturing cost, and shorten the manufacturing cycle. The electromagnetic coils of the distributed winding will span the tooth part of the stator, so there will be a situation where the electromagnetic coils overlap or intersect. Its advantage is that the harmonic content in the stator magnetomotive force is reduced and the influence of the stator teeth and slots on the magnetic field distribution is reduced, so that the pulsating voltage amplitude of the motor is reduced. That is to say, the distributed winding can synthesize the desired and most ideal magnetic field waveform for the user through a complex array of electromagnetic coils at the end of each tooth part of the stator to reduce the noise and vibration of the motor. The first winding 1022 and the second winding 1042 can select the winding method according to the actual design requirements, and the embodiments of the present invention do not make specific limitations.

[0055] Optionally, continue to refer to Figure 1 , the first stator 102, the second stator 104 and the rotor 103 are all formed by laminating silicon steel sheets.

[0056] Among them, the silicon steel sheet has the characteristics of high saturation magnetization intensity and low magnetic permeability, and the silicon steel sheet has high structural strength, so as to provide high supporting force for the first stator 102, the second stator 104 and the rotor 103 to improve the structural strength. Exemplarily, when preparing the first stator 102, a precision punching machine is used to punch the silicon steel sheet with high magnetic permeability, low iron loss and good mechanical properties into an annular shape with a stator slot structure, and annealing treatment is carried out to eliminate internal stress and improve magnetic properties. The punched silicon steel sheets are laminated together according to the design requirements by using a hydraulic press or a mechanical press. It is also necessary to perform turning processing on the outer circle and inner hole of the stator to ensure dimensional accuracy and surface finish, and remove the burrs generated during punching and processing to avoid affecting the performance of the motor. The first stator 102, the second stator 104 and the rotor 103 can all be formed by laminating silicon steel sheets to ensure the performance of the formed motor.

[0057] Optionally, continue to refer to Figure 1 , the first stator 102 and the second stator 104 are made of silicon steel sheets or amorphous alloys.

[0058] Among them, the materials of the first stator 102 and the second stator 104 can be silicon steel sheets, which have the characteristics of high saturation magnetization intensity and low magnetic permeability, and the silicon steel sheets have high structural strength to improve the structural strength. The materials of the first stator 102 and the second stator 104 can also be prepared from amorphous alloys. Compared with silicon steel sheets, amorphous alloy materials have higher magnetic permeability and lower saturation magnetization intensity, which improves the distribution uniformity of the magnetic flux density of the first stator 102 and the second stator 104, and further improves the magnetic field intensity of the first stator 102 and the second stator 104, thereby increasing the motor power and reducing magnetic leakage to improve the operating stability of the motor. The material selection of the first stator 102 and the second stator 104 can be selected according to actual design requirements, and the embodiments of the present invention do not make specific limitations.

[0059] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A permanent magnet synchronous motor, characterized in that, The permanent magnet synchronous motor includes: a rotating shaft (101), a first stator (102), a rotor (103), a second stator (104), and a plurality of permanent magnets (105). The rotor (103) is located between the first stator (102) and the second stator (104) and is coaxially arranged with the rotating shaft (101). The first stator (102) and the second stator (104) are coaxially arranged and fixed to the rotating shaft (101). The first stator (102) includes a plurality of first stator slots (1021) arranged at intervals in the circumferential direction. The first stator slots (1021) include first windings (1022). The second stator (104) includes a plurality of second stator slots (1041) arranged at intervals in the circumferential direction. The second stator slots (1041) include second windings (1042). The rotor (103) includes a plurality of rotor cores (1031) arranged at intervals in the circumferential direction. The permanent magnets (105) are tangentially placed on the rotor cores (1031) and the permanent magnets (105) have a tangential magnetic circuit structure. The polarities of adjacent permanent magnets (105) are the same.

2. The permanent magnet synchronous motor according to claim 1, wherein The first stator (102) and the rotor (103) are spaced apart to form a first air gap. The second stator (104) and the rotor (103) are spaced apart to form a second air gap.

3. The permanent magnet synchronous motor according to claim 1, wherein, There is no magnetic conduction between two adjacent rotor cores (1031).

4. The permanent magnet synchronous motor according to claim 1, wherein The slot positions of the first stator slots (1021) and the second stator slots (1041) are aligned.

5. The permanent magnet synchronous motor according to claim 1, characterized in that, When the rotor (103) rotates, the phase splitting phases of the first winding (1022) and the second winding (1042) differ by 180 electrical degrees.

6. The permanent magnet synchronous motor according to claim 1, wherein The first winding (1022) and the second winding (1042) are phase-split according to the slot electromotive force star diagram.

7. The permanent magnet synchronous motor according to claim 1, wherein The rotor core (1031) is provided with two first convex keys (106) and two second convex keys (107) which are symmetrically arranged. The two first convex keys (106) are located on the side of the rotor core (1031) close to the first stator (102), and the two second convex keys (107) are located on the side of the rotor core (1031) close to the second stator (104).

8. The permanent magnet synchronous motor according to claim 1, wherein, The first winding (1022) and the second winding (1042) are concentrated windings or distributed windings.

9. The permanent magnet synchronous motor according to claim 1, wherein The first stator (102), the second stator (104), and the rotor (103) are all formed by laminating silicon steel sheets.

10. The permanent magnet synchronous motor according to claim 1, characterized in that, The materials of the first stator (102) and the second stator (104) are silicon steel sheets or amorphous alloys.

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