Stator assembly, permanent magnet synchronous motor, compressor and refrigeration device

Abstract

The application discloses a kind of stator assembly, permanent magnet synchronous motor, compressor and refrigeration equipment, it is related to refrigeration equipment technical field, stator assembly includes stator core and stator winding, stator core includes stator yoke and stator tooth, stator slot is formed between two adjacent stator teeth, the number of stator slot is m, the maximum outer circle profile radius of stator core is r, the thickness of stator core along its axial direction is T;Stator winding is wound on stator tooth, the number of turns on each stator tooth is n, the wiring mode of stator winding is triangle connection, the number of parallel branch of each phase stator winding is N;Wherein, N, T, r, m and n satisfy: 0.20≤(n×N×m) / (T×r)≤1.92.The technical scheme provided by the application improves the efficiency of permanent magnet synchronous motor by adopting the structure of triangle connection combined with multiple parallel branches, and limits 0.20≤(n×N×m) / (T×r)≤1.92.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration equipment, in particular to a stator assembly, a permanent magnet synchronous motor, a compressor and a refrigeration equipment. BACKGROUND

[0002] The compressor of a partial variable frequency air conditioner (such as a parked air conditioner and a base station air conditioner) is powered by a low-voltage power supply, resulting in a motor operating current much higher than that of a conventional voltage model. At the same time, due to the limited installation space and working frequency, such a low-voltage motor needs to carry a large current, and the traditional design needs to use thick wire. However, thick wires are difficult to arrange evenly in limited slots, increasing the difficulty of wire embedding and further affecting the effective slot fill rate of the motor winding, thereby affecting the efficiency of the motor. SUMMARY

[0003] The main purpose of the present application is to provide a stator assembly, a permanent magnet synchronous motor, a compressor and a refrigeration equipment, which aims to improve the efficiency of the permanent magnet synchronous motor.

[0004] To achieve the above-mentioned purpose, the stator assembly provided by the present application comprises:

[0005] A stator core comprising a stator yoke and a plurality of stator teeth, the plurality of stator teeth being arranged at intervals along the inner periphery of the stator yoke, a stator slot being formed between adjacent two stator teeth, the number of stator slots being m, the maximum outer contour radius of the stator core being r, and the thickness of the stator core along its axial direction being T;

[0006] A stator winding, the stator winding being wound on the stator teeth, the number of turns of the stator winding on each stator tooth being n, the connection mode of the stator winding being a delta connection, and the number of parallel branches of each phase of the stator winding being N;

[0007] Wherein, N, T, r, m and n satisfy: 0.20≤(n×N×m) / (T×r)≤1.92.

[0008] In an embodiment, N satisfies: N=1.

[0009] In an embodiment, N satisfies: N=3.

[0010] In an embodiment, the maximum wire diameter D of the stator winding satisfies: 0.6mm≤D≤1.4mm.

[0011] In an embodiment, the stator assembly further comprises an insulating framework, the insulating framework being arranged at one end of the stator core in the axial direction and extending along the circumferential direction of the stator core, the insulating framework being provided with a bundling hole along its circumferential direction for the passage of a bundling belt, and the number of bundling holes being k, k satisfying: k≥2.

[0012] In an embodiment, each of the bundling holes has a cross-sectional area S, and S satisfies S≥25mm 2 .

[0013] The application further provides a permanent magnet synchronous motor comprising the stator assembly.

[0014] In an embodiment, the permanent magnet synchronous motor further comprises a motor rotor, the stator core is sleeved on an outer periphery of the motor rotor, and the motor rotor comprises a rotor core and permanent magnets, and the rotor core is provided with a plurality of magnet mounting grooves in a circumferential direction thereof.

[0015] The magnet mounting grooves comprise two first groove segments and a second groove segment, the two first groove segments are symmetrically arranged about a radial direction of the rotor core and extend away from a symmetry axis in a direction from an axis of the rotor core to an edge of the rotor core, two ends of the second groove segment are respectively communicated with one end of the two first groove segments close to the axis of the rotor core, and one of the permanent magnets is arranged in each of the two first groove segments and the second groove segment.

[0016] The application further provides a compressor comprising the permanent magnet synchronous motor.

[0017] The application further provides a refrigeration device comprising the compressor, and the refrigeration device is a stationary frequency conversion air conditioner or a base station frequency conversion air conditioner.

[0018] The stator winding of the technical scheme of the application adopts the structure of the combination of the delta connection and the multiple parallel branches, so that the permanent magnet synchronous motor can adopt a stator winding with a smaller wire diameter, which not only reduces the difficulty of embedding the stator winding, but also is beneficial to improving the slot fill rate of the stator winding; meanwhile, by constraining the structure size and electromagnetic design parameters of the permanent magnet synchronous motor: 0.20≤(n×N×m) / (T×r)≤1.92, it is ensured that the permanent magnet synchronous motor can realize efficient electromagnetic conversion under a compact structure, thereby effectively solving the problems of low slot fill rate, winding difficulty and high loss caused by thick wires in a low-voltage and high-current motor, thereby improving the efficiency of the permanent magnet synchronous motor and enhancing the manufacturing process and product reliability. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0020] Figure 1 It is a top view of an embodiment of the permanent magnet synchronous motor provided by the application.

[0021] Figure 2 The stator winding adopts the delta connection with the parallel branch number being 1;

[0022] Figure 3 The stator winding adopts the delta connection with the parallel branch number being 3;

[0023] Figure 4 The structure schematic view of one embodiment of the permanent magnet synchronous motor provided by the application is shown in the figure;

[0024] Figure 5 The side view of the permanent magnet synchronous motor in the figure; Figure 4

[0025] Figure 6 The structure schematic view of one embodiment of the insulation framework provided by the application is shown in the figure;

[0026] Figure 7 The top view of one embodiment of the motor rotor provided by the application is shown in the figure;

[0027] Figure 8 The efficiency comparison chart of the permanent magnet synchronous motor and the conventional motor of the same volume is shown in the figure;

[0028] Figure 9 The efficiency curve chart of the motor with the change of (n x N x m) / (T x r) is shown in the figure.

[0029] Explanation of the figure mark:

[0030] 100, stator core; 110, stator slot; 200, stator winding; 300, insulation framework; 310, bundling hole; 400, rotor core; 410, magnet mounting slot; 411, first slot section; 412, second slot section; 500, permanent magnet.

[0031] The realization of the object, the functional features and the advantages of the application will be further explained by combining the embodiments with the figures. Specific implementation

[0032] The technical solutions in the embodiments of the application will be clearly and completely described below by combining the figures in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the application.

[0033] ​It should be noted that if the embodiments of the present application involve directionality indication (such as up, down, left, right, front, back, etc.), the directionality indication is only used to explain the relative position relationship, motion condition, etc. between components in a certain posture, and if the certain posture changes, the directionality indication also changes accordingly.

[0034] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0035] The present application provides a stator assembly.

[0036] Please refer to Figures 1 to 5 In an embodiment of the present application, the stator assembly includes a stator core 100 and a stator winding 200, the stator core 100 includes a stator yoke and a stator tooth, a plurality of stator teeth are arranged at intervals along the inner periphery of the stator yoke, a stator slot 110 is formed between adjacent two stator teeth, the number of stator slots 110 is m, the maximum outer contour radius of the stator core 100 is r, and the thickness of the stator core 100 along its axial direction is T; the stator winding 200 is wound on the stator tooth, the number of turns on each stator tooth is n, the connection mode of the stator winding 200 is delta connection, and the number of parallel branches of each phase stator winding 200 is N; wherein N, T, r, m and n satisfy: 0.20≤(n×N×m) / (T×r)≤1.92.

[0037] Specifically, the stator assembly includes a motor stator, which includes a stator core 100 and a stator winding 200. The stator core 100 is made of silicon steel plates stacked together. The thickness T of the stator core 100 in its axial direction is the thickness of the multiple layers of silicon steel sheets stacked together, which determines the thickness and heat dissipation area of the permanent magnet synchronous motor in the axial direction, and can directly affect the power and volume of the permanent magnet synchronous motor. The maximum outer contour radius r of the stator core 100 is half of the outer diameter of the stator, and r and T together determine the total volume of the motor stator and the size of the force arm of the electromagnetic torque. The stator teeth of the stator core 100 extend inward from the stator yoke, and the stator slots 110 are formed between adjacent two stator teeth for embedding the winding. The number of stator slots 110 is m, which determines the pole-slot matching relationship of the motor and affects the electromagnetic performance, harmonics, cogging torque, etc. of the motor. The stator winding 200 is wound on the stator teeth, and generates a rotating magnetic field after being energized to drive the motor rotor to rotate. The number of turns n on each stator tooth and the number of parallel branches N together determine the total ampere-turns of each phase winding, which affects the back electromotive force and inductance of the permanent magnet synchronous motor. The number of parallel branches N of each phase stator winding 200 refers to the number of parallel paths into which each phase winding is divided. It affects the current size in each branch and the heat distribution of the winding, i.e. affects the selection of current distribution and wire thickness.

[0038] The stator winding 200 adopts a connection mode of a delta connection, i.e. the three-phase winding is connected end-to-end to form a closed triangle, and the line voltage is equal to the phase voltage. Compared with the star connection, the delta connection has higher phase voltage under the same line voltage, and therefore is more conducive to improving the power density and efficiency of the motor in a low-voltage power supply system. In a large-current application (such as a low-voltage compressor), the stator winding 200 can increase the utilization rate of the phase voltage under low-voltage conditions by adopting the delta connection, and by increasing the number of parallel branches N, the total current can be shunted to multiple paths, thereby allowing thinner wires to be used for winding. Thin wires have better flexibility and arrangement adaptability, can accommodate more copper materials in a limited slot space, effectively improve the slot fill rate, improve the uniformity of winding filling, reduce the void ratio, and thereby increase the equivalent conductor cross-sectional area, reduce the resistance and copper loss of the stator winding 200. In this way, the permanent magnet synchronous motor can use a stator winding 200 with a smaller wire diameter, which not only reduces the difficulty of embedding the stator winding 200, but also helps to improve the slot fill rate of the stator winding 200, thereby improving the efficiency of the permanent magnet synchronous motor.

[0039] The ratio of (n x N x m) / (T x r) comprehensively constrains the geometric size (T, r), electromagnetic design parameter (n, m), and electrical topology (N) of the permanent magnet synchronous motor, and reflects the matching relationship between the structure size and the electromagnetic design parameter of the permanent magnet synchronous motor. The denominator (T x r) represents the volume characteristics or power bearing capacity of the motor, and the numerator (n x N x m) represents the electromagnetic intensity and parallel degree of the stator winding 200. A reasonable range of the ratio ensures that sufficient electromagnetic output is guaranteed while avoiding problems such as saturation of the stator core 100, waste of materials, or low utilization of the stator winding 200 due to parameter mismatch. When (n x N x m) / (T x r) < 0.20, it may mean that the number of turns of the winding or the number of parallel branches is too large, which is easy to cause local overheating or complex process; when (n x N x m) / (T x r) > 1.92, it indicates that the structure is redundant or the electromagnetic design is insufficient, which affects the power density. Therefore, by limiting 0.20 ≤ (n x N x m) / (T x r) ≤ 1.92, an explicit optimization guide is provided for the design of the structure size and electromagnetic design parameter of the permanent magnet synchronous motor, ensuring efficient electromagnetic conversion under a compact structure, thereby improving the efficiency of the permanent magnet synchronous motor.

[0040] The measurement method of the maximum outer circular profile radius of the stator core 100: The maximum outer circular profile radius of the stator core 100 is r, which is the maximum distance from the center of the stator core 100 to its outer edge profile. If the outer edge of the stator core 100 is a complete circle, it can be directly measured, and the maximum value of the radius of the stator core 100 is r. If the outer edge of the stator core 100 is a non-complete circle with grooves, the maximum value of the radius of the stator core 100 is measured after determining the circle at the three outermost points of the circular arc.

[0041] The measurement method of the thickness of the stator core 100 in its axial direction: The stator core 100 has two end faces in its axial direction, and the distance between the two end faces is the thickness T of the stator core 100. The thickness of the stator core 100 can be measured using a vernier caliper, a micrometer, an ultrasonic thickness gauge, etc. For example, place the stator core 100 between the two jaws of the vernier caliper, so that the two jaws hold the two end faces of the stator core 100 in the axial direction to read the measured reading. To ensure the accuracy of the measurement, the vernier caliper can be gently slid along the radial direction of the stator core 100 and measured at multiple points.

[0042] The number of turns n on each stator tooth and the number of stator slots 110 can be directly observed.

[0043] Please refer to Figure 8 , Figure 8The efficiency comparison chart of the permanent magnet synchronous motor of the application and the conventional motor under the same volume is shown in the figure. When the rotating speed is 30rps, the efficiency of the conventional motor can reach 93.9%, and the efficiency of the permanent magnet synchronous motor of the application under the same volume can reach 94.8%; when the rotating speed is 60rps, the efficiency of the conventional motor can reach 94.3%, and the efficiency of the permanent magnet synchronous motor of the application under the same volume can reach 95.4%. That is, when the rotating speed is 30rps or 60rps, the efficiency of the permanent magnet synchronous motor of the application under the same volume is higher than that of the conventional motor.

[0044] Please refer to Figure 9 , Figure 9 The efficiency curve of the motor with (n x N x m) / (T x r) is shown in the figure. Figure 9 It can be seen that the motor efficiency of the permanent magnet synchronous motor of the application increases first and then decreases with the increase of (n x N x m) / (T x r), and the permanent magnet synchronous motor has a relatively optimal motor efficiency when 0.20≤(n x N x m) / (T x r)≤1.92. Specifically, when the rotating speed is 30rps and 0.20≤(n x N x m) / (T x r)≤1.92, the motor efficiency of the permanent magnet synchronous motor of the application is higher than 85%; when (n x N x m) / (T x r)=1.33, the motor efficiency is as high as 86.6%. When the rotating speed is 60rps and 0.20≤(n x N x m) / (T x r)≤1.92, the motor efficiency of the permanent magnet synchronous motor of the application is higher than 88.6%; when (n x N x m) / (T x r)=0.95, the motor efficiency is as high as 89.6%.

[0045] The stator winding 200 of the technical scheme of the application adopts the structure of combining the triangular connection with the multi-parallel branch, so that the permanent magnet synchronous motor can adopt the stator winding 200 with a smaller wire diameter, which not only can reduce the embedding difficulty of the stator winding 200, but also is beneficial to improving the slot fill rate of the stator winding 200. At the same time, by constraining the structure size and electromagnetic design parameters of the permanent magnet synchronous motor: 0.20≤(n x N x m) / (T x r)≤1.92, it is ensured that the permanent magnet synchronous motor can realize efficient electromagnetic conversion under a compact structure, thereby effectively solving the problems of low slot fill rate, winding difficulty and high loss caused by thick wires in low-voltage and high-current motors, thereby improving the efficiency of the permanent magnet synchronous motor and enhancing the manufacturing process and product reliability.

[0046] In an embodiment, please refer to Figure 2 , N satisfies: N=1.

[0047] The number of parallel branches N of each phase stator winding 200 is 1, i.e., the stator winding 200 is a single parallel branch structure. By adopting a delta connection, the utilization rate of phase voltage can be effectively improved under low-voltage conditions, and the winding topology structure is simplified by the single branch design, reducing the complexity of the end connection and the resistance loss.

[0048] When N = 1, 0.20≤(n×N×m) / (T×r)≤1.92 is simplified to 0.20≤(n×m) / (T×r)≤1.92. Wherein, T×r reflects the effective volume and magnetic flux carrying capacity of the motor, and n×m represents the total equivalent turn level, which directly affects the induced electromotive force and winding resistance. A reasonable range of this ratio ensures that by optimizing the geometric size and winding parameters without increasing the number of parallel branches, both core magnetic saturation or winding overheating can be avoided, and the slot space can be fully utilized to improve the slot fill rate and material utilization. In this way, the present application improves the voltage utilization rate by adopting a delta connection under the structure of N = 1, and constrains the structure size and electromagnetic design parameters of the permanent magnet synchronous motor. Compared with the multi-parallel branch design, the single branch structure reduces the welding points, reduces the end leakage inductance and contact resistance, and improves the reliability and power density of the system. At the same time, through the design of 0.20≤(n×m) / (T×r)≤1.92, the fine wire and dense arrangement and high filling rate winding process can be realized without relying on a complex stator winding 200 topology.

[0049] In another embodiment, please refer to Figure 3 , N satisfies: N = 3.

[0050] N = 3, i.e., each phase stator winding 200 has 3 parallel branches. The total current of each phase stator winding 200 is distributed to 3 parallel branches, further reducing the current carrying demand of a single branch, so that the stator winding 200 can use thinner diameter wires, or reduce the current density under the same wire diameter, thereby optimizing the thermal management of the permanent magnet synchronous motor. Fine wires have better flexibility and arrangement adaptability, which can realize tighter and more uniform arrangement in the limited stator slot 110 space, effectively improve the slot fill rate, reduce the gap, and increase the equivalent copper cross-sectional area. Higher slot fill rate not only improves the material utilization, but also reduces the direct current resistance of the stator winding 200, thereby reducing copper loss and improving the overall efficiency of the permanent magnet synchronous motor. In addition, the multi-branch design helps to improve the heat dissipation distribution and avoid local hot spots, improving the stability of the permanent magnet synchronous motor during long-term operation.

[0051] In an embodiment, the maximum wire diameter D of the stator winding 200 satisfies: 0.6mm≤D≤1.4mm.

[0052] By employing a structure combining delta connections and multiple parallel branches, and by constraining the structural dimensions and electromagnetic design parameters of the permanent magnet synchronous motor (0.20 ≤ (n × N × m) / (T × r) ≤ 1.92), the stator winding 200 can use wires with finer diameters. Thus, the stator winding 200 used in this invention can be selected between 0.6 mm and 1.4 mm in diameter. Wires within this range have moderate flexibility, facilitating automated winding and embedding, improving production efficiency and product consistency. It also avoids embedding damage from ultra-thick wires and the risk of breakage from ultra-fine wires, enhancing the mechanical and electrical reliability of the stator winding 200. Understandably, when the wire diameter of stator winding 200 is less than 0.6mm, the current carrying capacity of a single conductor decreases, requiring a significant increase in the number of parallel conductors or turns. This can easily lead to end congestion, increased risk of insulation damage, reduced mechanical strength, and increased susceptibility to wire breakage during winding, which is detrimental to automated production. On the other hand, when the wire diameter of stator winding 200 exceeds 1.4mm, the conductor rigidity increases, and the bending radius increases. This can easily cause uneven distribution and local compression within the narrow stator slot 110, resulting in a decrease in slot fill factor. It also increases the difficulty of winding, affecting product consistency and yield.

[0053] In one implementation, please refer to Figures 4 to 6 The stator assembly also includes an insulating frame 300, which is located at one end of the stator core 100 in the axial direction and extends circumferentially along the stator core 100. The insulating frame 300 is provided with binding holes 310 for cable ties to pass through along its circumference. The number of binding holes 310 is k, and k satisfies: k≥2.

[0054] The insulating frame 300 is disposed at one end of the stator core 100 in the axial direction (usually on the side near the end cover of the permanent magnet synchronous motor) and extends circumferentially along the stator core 100 to form a ring or segmented support structure. The insulating frame 300 is made of heat-resistant, electrical-resistant, and mechanically strong insulating material. It is mainly used to electrically isolate and mechanically fix the ends of the stator winding 200, prevent short circuits between the stator winding 200 and the metal end cover or housing, and provide structural support to resist deformation caused by vibration and thermal expansion and contraction.

[0055] The insulation skeleton 300 is provided with a plurality of bundling holes 310 in the circumferential direction, used for threading a bundling tape (such as a PET bundling tape or a metal clamp), to achieve fastening and bundling of the end of the stator winding 200 and the external lead wire. The number of bundling holes 310 is k, and satisfies: k≥2. In this way, it is ensured that the end of the stator winding 200 has at least two fixing points in the circumferential direction, forming a stable ring constraint, effectively preventing the stator winding 200 from loosening, shifting or wire whipping due to electromagnetic force or centrifugal force during high-speed rotation or frequent start-stop. When k=2, basic symmetrical fixing can be achieved; when k>2, the fixing points are more evenly distributed, and the bundling force is more balanced, further improving the overall rigidity and anti-vibration capability of the winding end. At the same time, multi-point bundling helps to reduce local stress concentration, avoid breaking of the bundling tape or cracking of the insulation skeleton 300, and prolong the service life of the motor.

[0056] In addition, the position of the bundling hole 310 is usually staggered with the slot opening of the stator tooth or stator slot 110, avoiding the bundling tape pressing the lead wire of the stator winding 200 or causing local insulation wear. By integrating the bundling structure on the insulation skeleton 300, functional integration and assembly automation are achieved, reducing the process of additional use of insulation end plates or tape wrapping, improving production efficiency and product consistency.

[0057] In an embodiment, please refer to Figure 4 The cross-sectional area of each bundling hole 310 is S, and S satisfies: S≥25mm 2 .

[0058] The cross-sectional area of the bundling hole 310 refers to the cross-sectional area of the bundling hole 310 in the plane perpendicular to the direction of the bundling tape threading. The width of the commonly used nylon bundling tape (such as medium or heavy specifications) in motor manufacturing is usually between 4.8mm and 9.5mm. When the bundling tape is threaded into the bundling hole 310 and tightened, its cross-section will change from flat to approximately rectangular or elliptical. S≥25mm 2 The design ensures that the size of the bundling hole 310 is sufficient to accommodate the mainstream industrial specifications of the bundling tape, avoiding the bundling tape from being stuck, deformed or difficult to thread due to the bundling hole 310 being too small, making the bundling tape threading smoother and faster, reducing jamming and rework, and improving the efficiency of automated or semi-automated assembly. The large enough cross-sectional area of the bundling hole 310 disperses the contact stress, protects the bundling tape and the insulation skeleton 300, and ensures smooth and reliable bundling. The bundling tape can be fully tightened without damage, to reduce the rejection rate caused by breaking of the bundling tape or damage to the skeleton, and maintain a stable bundling force for a long time, effectively resisting the dynamic load during operation of the permanent magnet synchronous motor.

[0059] The application further provides a permanent magnet synchronous motor, which comprises a stator assembly, and the specific structure of the stator assembly is referred to the above-mentioned embodiments. Since all the technical solutions of the above-mentioned embodiments are adopted in the permanent magnet synchronous motor, all the beneficial effects brought by the technical solutions of the above-mentioned embodiments are at least achieved, and thus will not be repeated here.

[0060] In an embodiment, referring to Figure 1 and Figure 7 , the permanent magnet synchronous motor further comprises a motor rotor, the stator core 100 is sleeved on the outer periphery of the motor rotor, the motor rotor comprises a rotor core 400 and permanent magnets 500, and the rotor core 400 is provided with a plurality of magnet mounting grooves 410 in the circumferential direction thereof at intervals. The magnet mounting groove 410 comprises two first groove sections 411 and one second groove section 412, the two first groove sections 411 are symmetrically arranged about the radial direction of the rotor core 400 and extend away from the symmetry axis in the direction from the axis of the rotor core 400 to the edge of the rotor core 400, the two ends of the second groove section 412 are respectively communicated with one end of the two first groove sections 411 close to the axis of the rotor core 400, and one permanent magnet 500 is arranged in each of the two first groove sections 411 and the second groove section 412.

[0061] The stator core 100 is sleeved on the outer periphery of the motor rotor, when the stator winding 200 is supplied with three-phase alternating current, a rotating magnetic field is generated, the permanent magnets 500 on the motor rotor interact with the rotating magnetic field to generate torque, thereby driving the permanent magnet synchronous motor to rotate. The motor rotor comprises the rotor core 400 and the permanent magnets 500, the permanent magnets 500 can generate a constant magnetic field and interact with the rotating magnetic field to generate torque, and the motor rotor can rotate relative to the motor stator to realize normal operation of the permanent magnet synchronous motor. The rotor core 400 is made of high-permeability magnetic material or silicon steel punching sheet and is laminated, has high magnetic flux rate and high structural strength, and is convenient to process. The permanent magnets 500 are embedded in the magnet mounting grooves 410, and the permanent magnets 500 under the same magnetic pole are required to have the same polarity in the direction of the outer periphery of the motor rotor when embedded, and the permanent magnets 500 of adjacent magnetic poles are required to have opposite magnetism, and a plurality of magnetic poles are distributed in the circumferential direction of the rotor core 400 in the order of N pole and S pole alternately.

[0062] The rotor core 400 is provided with a plurality of magnet mounting grooves 410 spaced apart along the circumference thereof, each of the magnet mounting grooves 410 comprising two first groove sections 411 and one second groove section 412. The two first groove sections 411 are symmetrically arranged about the radial direction of the rotor core 400 and extend away from the symmetry axis in the edge direction from the axis of the rotor core 400; the second groove section 412 is connected between the two first groove sections 411 near the axis of the rotor core 400, transversely penetrating, so that the entire magnet mounting groove 410 and the permanent magnet 500 form a U-shaped structure as a whole. Each of the two first groove sections 411 and the second groove section 412 is embedded with a permanent magnet 500, and the three together form a complete magnetic pole unit.

[0063] The U-shaped structure of the permanent magnet 500 enables the permanent magnet 500 to provide magnetic flux in both the radial and tangential directions, forming a multi-directional magnetic field modulation effect, enhancing the air gap magnetic flux amplitude and improving its sinusoidal nature, thereby improving the output torque and power density of the permanent magnet synchronous motor. The U-shaped groove structure of the permanent magnet 500 also helps to balance the magnetic resistance distribution, weaken the cogging torque harmonic, reduce vibration and noise, and improve the smoothness and comfort of the motor operation. Among them, the second groove section 412 is located in the central region of the motor rotor, and the magnetic flux generated by the permanent magnet 500 therein is guided outward through the permanent magnets 500 of the two first groove sections 411, forming a concentrated magnetic pole structure, effectively reducing the magnetic flux leakage and improving the utilization rate of the main magnetic flux.

[0064] The U-shaped structure of the permanent magnet 500 also enables higher magnetic pole strength and magnetic field modulation capability with a smaller motor rotor diameter, which helps to shorten the magnetic circuit and reduce the volume of the rotor core 400, thereby reducing the overall size of the permanent magnet synchronous motor under the premise of ensuring the output power, and meeting the stringent requirements of installation space for applications such as parking air conditioners and base station air conditioners.

[0065] The permanent magnet synchronous motor provided by the present application adopts a rotor structure with U-shaped permanent magnets 500, optimizes the magnetic flux path, realizes efficient concentration and utilization of the magnetic field, improves the air gap magnetic flux and the utilization rate of the magnetic steel, and effectively improves the power density and torque output capability of the motor. The permanent magnet synchronous motor is particularly suitable for low-voltage application scenarios, and in combination with the delta connection mode of the stator winding 200, the phase current can be greatly reduced, thereby allowing the use of thinner winding wire diameters. Thin wire diameters are more easily arranged uniformly in the stator slot 110, effectively improving the slot fill rate and copper material filling density, not only reducing the winding resistance and copper loss, but also significantly improving the wire embedding process and production consistency, and enhancing the manufacturability of low-voltage motors. At the same time, by constraining the structure size and electromagnetic design parameters of the permanent magnet synchronous motor: 0.20≤(n×N×m) / (T×r)≤1.92, it is ensured that the permanent magnet synchronous motor can realize efficient electromagnetic conversion under a compact structure, thereby improving the efficiency of the permanent magnet synchronous motor and enhancing the manufacturability and product reliability.

[0066] The application further provides a compressor comprising the permanent magnet synchronous motor, the specific structure of which is referred to the above embodiments, and the compressor adopts all the technical solutions of the above embodiments, so at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0067] The application further provides a refrigeration equipment comprising the compressor, the specific structure of which is referred to the above embodiments, and the refrigeration equipment adopts all the technical solutions of the above embodiments, so at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0068] The refrigeration equipment is a stationary frequency conversion air conditioner or a base station frequency conversion air conditioner.

[0069] The permanent magnet synchronous motor is particularly suitable for the stationary frequency conversion air conditioner and the base station frequency conversion air conditioner. The stationary frequency conversion air conditioner is installed on a vehicle (such as a truck, a commercial vehicle, a motor home, etc.), and when the engine of the vehicle is turned off or idling, the vehicle is provided with an air conditioning system for refrigeration / heat by using a vehicle battery or an auxiliary power supply. The stationary frequency conversion air conditioner relies on a low-voltage direct-current power supply for power supply. The permanent magnet synchronous motor of the application operates efficiently at low voltage, has small size and light weight, adapts to narrow installation space, and has low noise and high reliability, meeting the long-time stationary refrigeration requirement. The base station frequency conversion air conditioner is used for temperature control systems in communication base stations, data centers and other places, and requires high energy efficiency, long service life and low maintenance. The permanent magnet synchronous motor of the application is matched with frequency conversion control to realize precise speed regulation and energy-saving operation. The permanent magnet synchronous motor of the application can reduce the power consumption of the compressor, thereby directly improving the energy efficiency ratio of the stationary frequency conversion air conditioner or the base station frequency conversion air conditioner, and realizing energy-saving operation.

[0070] The above only describes the exemplary embodiments of the application, and does not limit the patent scope of the application, and any equivalent structural transformation made by referring to the content of the specification and drawings of the application, or direct / indirect application in other related technical fields is included in the patent protection scope of the application.

Claims

1. A stator assembly characterized by, The stator assembly comprises: a stator core comprising a stator yoke and stator teeth, a plurality of the stator teeth being arranged at intervals along the inner periphery of the stator yoke, a stator slot being formed between two adjacent stator teeth, the number of the stator slots being m, the maximum outer profile radius of the stator core being r, and the thickness of the stator core along its axial direction being T; a stator winding, the stator winding being wound on the stator teeth, the number of turns of the stator winding on each stator tooth being n, the connection mode of the stator winding being delta connection, and the number of parallel branches of each phase of the stator winding being N; wherein N, T, r, m and n satisfy: 0.20≤(n×N×m) / (T×r)≤1.

92.

2. The stator assembly of claim 1, wherein, N satisfies: N=1.

3. The stator assembly of claim 1, wherein, N satisfies: N=3.

4. The stator assembly of claim 1, wherein, The maximum wire diameter D of the stator winding satisfies: 0.6mm≤D≤1.4mm.

5. The stator assembly of claim 1, wherein, The stator assembly further comprises an insulating framework, the insulating framework being arranged at one end of the stator core in the axial direction and extending along the circumferential direction of the stator core, the insulating framework being provided with a bundling hole for a bundling belt to pass through along the circumferential direction thereof, and the number of the bundling holes being k, k satisfying: k≥2.

6. The stator assembly of claim 5, wherein, Each of the bundling holes has a cross-sectional area S, S satisfies: S≥25mm 2 .

7. A permanent magnet synchronous motor, characterized by, The compressor comprises the stator assembly according to any one of claims 1 to 6.

8. The permanent magnet synchronous motor of claim 7, wherein, The permanent magnet synchronous motor further comprises a motor rotor, the stator core being sleeved on the outer periphery of the motor rotor, the motor rotor comprising a rotor core and permanent magnets, and a plurality of magnet mounting slots being arranged at intervals along the circumferential direction of the rotor core; The magnet mounting slot comprises two first slot segments and one second slot segment, the two first slot segments being symmetrically arranged about the radial direction of the rotor core and extending away from the symmetry axis in the direction from the axis of the rotor core to the edge of the rotor core, the two ends of the second slot segment being in communication with one end of the two first slot segments close to the axis of the rotor core, and one permanent magnet being arranged in each of the two first slot segments and the second slot segment.

9. A compressor characterized by, The compressor comprises the permanent magnet synchronous motor according to any one of claims 7 or 8.

10. A refrigeration appliance characterized in that, The compressor comprises the compressor according to claim 9, and the refrigeration equipment is a stationary variable frequency air conditioner or a base station variable frequency air conditioner.

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