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

Abstract

The invention discloses a stator assembly, a permanent magnet synchronous motor, a compressor and refrigeration equipment, and relates to the technical field of refrigeration equipment, the stator assembly comprises a stator iron core and a stator winding, the stator iron core comprises a stator yoke and stator teeth, a stator groove is formed between every two adjacent stator teeth, the number of the stator grooves is m, the maximum outer circle contour radius of the stator iron core is r, the thickness of the stator core along the axial direction is T; the stator winding is wound on the stator teeth, the number of winding turns on each stator tooth is n, the wiring mode of the stator winding is triangular connection, and the number of parallel branches of each phase of stator winding is N; wherein N, T, r, m and n satisfy 0.20 < = (n * N * m) / (T * r) < = 1.92. According to the technical scheme provided by the invention, the stator winding adopts a structure of combining triangular connection and multiple parallel branches, and (n * N * m) / (T * r) is limited to be greater than or equal to 0.20 and less than or equal to 1.92, so that the efficiency of the permanent magnet synchronous motor is improved.

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 part of variable frequency air conditioners (such as a parked air conditioner and a base station air conditioner) is powered by a low-voltage power supply, which results in a motor operating current much higher than that of a conventional voltage model. Meanwhile, limited by installation space and working frequency, such a low-voltage motor needs to carry a large current, and a traditional design needs to use thick wire. However, thick wires are prone to uneven arrangement in limited slots, which increases the difficulty of wire embedding and further affects 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: 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; 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; Wherein, N, T, r, m and n satisfy: 0.20≤(n×N×m) / (T×r)≤1.92.

[0005] In an embodiment, N satisfies: N=1.

[0006] In an embodiment, N satisfies: N=3.

[0007] In an embodiment, the maximum wire diameter D of the stator winding satisfies: 0.6mm≤D≤1.4mm.

[0008] 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.

[0009] In an embodiment, the cross-sectional area of each bundling hole is S, S satisfying: S≥25mm 2 .

[0010] The application further provides a permanent magnet synchronous motor comprising the stator assembly.

[0011] In an embodiment, the permanent magnet synchronous motor further comprises a motor rotor, the stator core is sleeved on the outer periphery of the motor rotor, the motor rotor comprises a rotor core and permanent magnets, and the rotor core is provided with a plurality of magnet mounting grooves in the circumferential direction thereof. The magnet mounting grooves comprise two first groove segments and a second groove segment, the two first groove segments are symmetrically arranged about the radial direction of the rotor core and extend 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 groove segment are respectively communicated with one end of the two first groove segments close to the axis of the rotor core, and one permanent magnet is arranged in each of the two first groove segments and the second groove segment.

[0012] The application further provides a compressor comprising the permanent magnet synchronous motor.

[0013] 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.

[0014] 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 large-current motor, thereby improving the efficiency of the permanent magnet synchronous motor and enhancing the manufacturing process and product reliability. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical schemes in the embodiments of the application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the application, and other accompanying drawings can be obtained by those skilled in the art without creative labor on the basis of the shown structures.

[0016] Figure 1 It is a top view of an embodiment of the permanent magnet synchronous motor provided by the application; Figure 2 It is a delta connection method when the number of parallel branches of the stator winding is 1; Figure 3 The stator winding adopts a delta connection with three parallel branches; Figure 4 A structure schematic diagram of an embodiment of the permanent magnet synchronous motor provided by the application is shown in the figure; Figure 5 A side view of the permanent magnet synchronous motor in the figure; Figure 4 Figure 6 A structure schematic diagram of an embodiment of the insulation framework provided by the application is shown in the figure; Figure 7 A top view of an embodiment of the motor rotor provided by the application is shown in the figure; Figure 8 A comparison diagram of the efficiency of the permanent magnet synchronous motor of the application and a conventional motor under the same volume is shown in the figure; Figure 9 A curve diagram of the motor efficiency changing with (n x N x m) / (T x r) is shown in the figure.

[0017] Explanation of the figure reference: 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.

[0018] The realization of the object, functional features and advantages of the application will be further described by combining with the embodiments and referring to the figures. DETAILED DESCRIPTION

[0019] 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, but not all the embodiments of the application. 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.

[0020] It should be noted that if the embodiments of the 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, movement condition, etc. between the components in a certain specific posture, and if the specific posture changes, the directionality indication also changes accordingly.

[0021] ​In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0022] The present application provides a stator assembly.

[0023] Please refer to Figures 1 to 5 In an embodiment of the present application, the stator assembly comprises a stator core 100 and a stator winding 200, the stator core 100 comprises a stator yoke and a plurality of stator teeth, the plurality of stator teeth are arranged at intervals along the inner periphery of the stator yoke, a stator slot 110 is formed between two adjacent 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 teeth, the number of turns of the stator winding 200 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.

[0024] 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.

[0025] 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.

[0026] The ratio of (n x N x m) / (T x r) comprehensively constrains the structure and electromagnetic parameters of the permanent magnet synchronous motor (T, r), electromagnetic design parameters (n, m), and electrical topology (N), and reflects the matching relationship between the structure size and electromagnetic design parameters of the permanent magnet synchronous motor. The denominator (T x r) represents the volume characteristics or power carrying 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 parameters of the permanent magnet synchronous motor, ensuring efficient electromagnetic conversion under a compact structure, thereby improving the efficiency of the permanent magnet synchronous motor.

[0027] 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 as r after determining the circle at the three outermost points of the circular arc.

[0028] 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, the stator core 100 is placed between the two measuring jaws of the vernier caliper, so that the two measuring jaws clamp 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 to move along the radial direction of the stator core 100, and multiple points are measured.

[0029] The number of turns n on each stator tooth and the number of stator slots 110 can be directly observed.

[0030] Please refer to Figure 8 , Figure 8This chart compares the efficiency of the permanent magnet synchronous motor of this invention with that of a conventional motor of the same volume. At a speed of 30 rpm, the conventional motor achieves an efficiency of 93.9%, while the permanent magnet synchronous motor of this invention achieves 94.8% for the same volume. At a speed of 60 rpm, the conventional motor achieves an efficiency of 94.3%, while the permanent magnet synchronous motor of this invention achieves 95.4% for the same volume. In other words, at speeds of 30 rpm and 60 rpm, the permanent magnet synchronous motor of this invention is more efficient than the conventional motor for the same volume.

[0031] Please see Figure 9 , Figure 9 This is a graph showing the change in motor efficiency as a function of (n×N×m) / (T×r). From... Figure 9 It can be seen that the motor efficiency of the permanent magnet synchronous motor of the present invention first increases and then decreases with the increase of (n×N×m) / (T×r), and the permanent magnet synchronous motor has better motor efficiency when 0.20≤(n×N×m) / (T×r)≤1.92. Specifically, at a speed of 30 rpm and 0.20≤(n×N×m) / (T×r)≤1.92, the motor efficiency of the permanent magnet synchronous motor of the present invention is higher than 85%; where the motor efficiency reaches as high as 86.6% when (n×N×m) / (T×r)=1.33. At a speed of 60 rpm and 0.20≤(n×N×m) / (T×r)≤1.92, the motor efficiency of the permanent magnet synchronous motor of the present invention is higher than 88.6%; where the motor efficiency reaches as high as 89.6% when (n×N×m) / (T×r)=0.95.

[0032] The stator winding 200 of the present invention adopts a structure combining delta connection and multiple parallel branches, which allows the permanent magnet synchronous motor to use a stator winding 200 with a smaller wire diameter. This not only reduces the difficulty of winding the stator winding 200, but also helps to improve the slot fill factor of the stator winding 200. At the same time, by constraining the structural dimensions 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 achieve efficient electromagnetic conversion in a compact structure. This effectively solves the problems of low slot fill factor, winding difficulty and high loss caused by thick wire in low-voltage high-current motors, thereby improving the efficiency of the permanent magnet synchronous motor and enhancing the manufacturability and product reliability.

[0033] In one implementation, please refer to Figure 2 N satisfies: N=1.

[0034] 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.

[0035] 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.

[0036] In another embodiment, please refer to Figure 3 , N satisfies: N = 3.

[0037] 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. Thin 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.

[0038] In an embodiment, the maximum wire diameter D of the stator winding 200 satisfies: 0.6mm≤D≤1.4mm.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In an embodiment, referring to Figure 4 The cross-sectional area of each bundling hole 310 is S, and S satisfies: S≥25mm 2 .

[0045] 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, protecting the bundling tape and the insulation skeleton 300, ensuring smooth and reliable bundling process. The bundling tape can be fully tightened without damage, reducing the rejection rate due to bundling tape breakage or skeleton damage, and maintaining a stable bundling force for a long time, effectively resisting the dynamic load during operation of the permanent magnet synchronous motor.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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, and extends transversely to form a U-shaped structure as a whole for the entire magnet mounting groove 410 and the permanent magnet 500. 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.

[0050] The U-shaped structure of the permanent magnet 500 enables the permanent magnet 500 to provide magnetic flux in both the radial direction and the tangential direction, 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 thereof 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.

[0051] The U-shaped structure of the permanent magnet 500 also enables higher magnetic pole strength and magnetic field modulation capability under 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] The refrigeration equipment is a stationary frequency conversion air conditioner or a base station frequency conversion air conditioner.

[0056] 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.

[0057] 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.

Images