Permanent magnet motor, compressor and refrigeration equipment

Abstract

The invention discloses a permanent magnet motor, a compressor and refrigeration equipment, and relates to the technical field of motors, the permanent magnet motor comprises a stator and a rotor, and each magnetic steel groove group in the circumferential direction of the rotor corresponds to one magnetic pole; the adjacent magnetic steel grooves in the same magnetic steel groove group are separated by an inner magnetic bridge; magnets are arranged in all the magnetic steel grooves; the maximum outer diameter of the rotor is D1; the sum of the lengths of the longest sides of the magnets in the same magnetic steel groove group is L1, and the length of the minimum side of any magnet in the same magnetic steel groove group is L2; the minimum width of the inner magnetic bridge is A1; the minimum distance from the magnetic steel grooves to the outer circle outline of the rotor is A2; the number of the stator slots is Q, the number of pole pairs of the rotor is P. The above parameters are constrained to meet the corresponding relational expressions, and the technical scheme provided by the invention can improve the structural strength of the motor rotor, ensure the operation reliability of the motor, and promote the broadband development of the compressor, thereby giving consideration to more application fields.

Description

Technical Field

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

[0002] Permanent magnet motors (PMMs) serve as core power components in compressors, refrigeration equipment, and household appliances. Their operational stability and wide-band adaptability directly impact the performance of end products. As market demand for broadband compressors (i.e., support for operation over a wider frequency range) increases, the limitations of traditional PMMs in high-frequency operation scenarios are becoming increasingly apparent. When operating at high frequencies, the rotors of traditional motors are subject to centrifugal force (generated by high-speed rotation) and magnetic pull (generated by the interaction between the stator and rotor magnetic fields). This can lead to structural deformation, increased vibration, or performance degradation, limiting the compressor's ability to adapt to a wider operating frequency range. Summary of the Invention

[0003] The main purpose of the present invention is to propose a permanent magnet motor, a compressor and a refrigeration device, aiming to improve the structural strength of the motor rotor, ensure the reliability of the motor operation, extend the service life of the motor, and help promote the broadband development of the compressor, thereby taking into account more application fields.

[0004] To achieve the above-mentioned object, the permanent magnet motor proposed in the present invention comprises: a stator comprising a plurality of stator slots uniformly distributed along the circumferential direction; and A rotor, the rotor being disposed inside the stator, the rotor having a plurality of magnetic steel slot groups evenly distributed in the circumferential direction thereof, each magnetic steel slot group corresponding to a magnetic pole; each magnetic steel slot group including at least two magnetic steel slots; adjacent magnetic steel slots within the same magnetic steel slot group being separated by an internal magnetic bridge; and magnets being disposed in all magnetic steel slots; The maximum outer diameter of the rotor is D1; ​​the sum of the lengths of the longest sides of the magnets in the same magnetic steel slot group on the rotor cross section is L1, and the minimum side length of any magnet in the same magnetic steel slot group is L2; ​​the minimum width of the internal magnetic bridge in the same magnetic steel slot group in the direction perpendicular to the rotor radial direction is A1; the minimum distance from the slot wall of the magnetic steel slot in the same magnetic steel slot group away from the center of the rotor to the outer contour of the rotor is A2; the number of stator slots is Q, and the number of pole pairs of the rotor is P; the relationship is satisfied: 1.5≤ ≤2.5, where GCD(Q,P) is the greatest common divisor of Q and P.

[0005] In one embodiment, the axial height of the rotor is H, the minimum inner diameter of the stator is D2, and the relationship is satisfied: 21≤ ≤30.

[0006] In one embodiment, the rotor has a shaft hole for transmission connection, and the minimum inner diameter of the shaft hole is D3, 0.5≤ ≤0.9.

[0007] In one embodiment, 15≤Q≤18.

[0008] In one embodiment, 5≤P≤6.

[0009] In one embodiment, the number of phases of the motor is m, the number of slots per pole per phase is q, and q=Q / 2mP, wherein 0<q<1.

[0010] In one embodiment, 5≤GCD(Q,P)≤6.

[0011] In one embodiment, 0.3 mm ≤ A1 ≤ 0.7 mm.

[0012] In one embodiment, 50 mm ≤ D1 ≤ 90 mm.

[0013] The present invention further provides a compressor, comprising the permanent magnet motor and a pump body assembly as described above, wherein the pump body assembly comprises a crankshaft, and the crankshaft is in driving cooperation with the rotor.

[0014] The present invention also provides a refrigeration device comprising the compressor as described above.

[0015] The technical solution of the present invention is to constrain the parameters 1.5≤ ≤2.5, balance between structural strength and electromagnetic properties, molecular It is related to the effective volume of the magnet and the radial size of the rotor, and affects the torque output capacity of the motor; the denominator This reflects the rotor's "structural strength coefficient" (A1 and A2 influence mechanical strength, while the GCD value of the slot-pole match influences magnetic field stability). If the ratio is too small (<1.5), structural strength is excessive but electromagnetic performance is insufficient (torque output is limited). Specifically, when the relationship is less than 1.5, while the rotor's mechanical strength is significantly improved, magnet leakage increases significantly with the increase in the size of the magnetic bridge (A1 and A2) and the number of motor units, resulting in reduced magnet utilization and motor efficiency, which in turn affects motor performance. If the ratio is too large (>2.5), electromagnetic performance is strong but structural strength is insufficient (prone to deformation at high frequencies). Specifically, when the relationship is greater than 2.5, mechanical strength and rigidity are insufficient. Undersized magnetic bridges (A1 and A2) can cause fracture during high-speed operation, leading to stator-rotor seizure and compressor failure. This relationship balances centrifugal force and motor cost-effectiveness, achieving optimal motor design and reducing R&D costs and the risk of quality fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 A schematic structural diagram of an embodiment of a rotor and a stator provided by the present invention; Figure 2 is a schematic structural diagram of an embodiment of a rotor; Figure 3 is a schematic structural diagram of another embodiment of a rotor; Figure 4 1 is a schematic structural diagram of another embodiment of a rotor; Figure 5 1 is a structural diagram of a stator according to an embodiment of the present invention; Figure 6 A schematic structural diagram of an embodiment of a compressor provided by the present invention; Figure 7 This is a curve diagram showing the relationship between the rotor tensile strength and the motor efficiency; Figure 8 is a curve diagram showing the relationship between the rotor magnetic pull and the maximum output torque; Figure 9 This is a curve diagram showing the relationship between shaft rigidity and compressor energy efficiency.

[0018] Description of Figure Numbers: 100, stator; 110, stator slot; 200, rotor; 210, magnetic steel slot group; 220, magnetic steel slot; 230, inner magnetic bridge; 240, outer magnetic bridge; 250, shaft hole; 260, magnetic isolation bridge; 300, magnet; 400. Pump body assembly; 410. Crankshaft.

[0019] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] In the fields of compressors, refrigeration equipment, and household appliances, permanent magnet motors are core power components. Their operating stability and wide-band adaptability directly affect the performance of the end products. As the market demand for wide-band compressors (i.e., supporting operation over a wider frequency range) increases, the limitations of traditional permanent magnet motors in high-frequency operation scenarios are gradually becoming apparent: When traditional motors operate at high frequencies, the rotor is affected by centrifugal force (generated by high-speed rotation) and magnetic pull (generated by the interaction between the stator and rotor magnetic fields), resulting in structural deformation, increased vibration or performance degradation, limiting the wide-bandwidth capability of the compressor (i.e., adaptability to a wider operating frequency range).

[0024] These issues collectively limit the motor's stable operation in high-frequency bands, making it unable to meet the comprehensive requirements of broadband compressors for high rigidity, low interference, and a wide operating range. Therefore, a permanent magnet motor design solution is urgently needed that optimizes key rotor structural parameters to simultaneously improve mechanical strength and electromagnetic performance, thereby promoting the development of broadband compressors.

[0025] Specifically, high-speed rotor rotation during high-frequency operation generates significant centrifugal force. If the rotor structure lacks rigidity (e.g., the inner magnetic bridge between the magnet slots is too narrow, or the distance from the magnet slots to the outer circumference is too small), the rotor core can easily deform or even crack, affecting mechanical reliability. Furthermore, the interaction between the stator and rotor magnetic fields generates magnetic pull fluctuations. If the number of stator slots and the number of rotor pole pairs are not properly matched, harmonic interference can be exacerbated, causing vibration and noise. Because the traditional single-magnet structure (one slot per pole) concentrates centrifugal force in the center of the magnet during high-speed operation, it can cause the magnet to shift or even break, forcing the speed to be limited. Furthermore, increasing the magnet size to increase magnetic flux (e.g., widening the circumferential length L1 of the magnet) requires sacrificing the rotor's mechanical strength. Reducing the inner magnetic bridge width A1 reduces bending stiffness (making centrifugal deformation more likely). Furthermore, reducing the distance A2 from the outer wall of the magnetic slots increases the risk of tearing the rotor's outer circumference, which can easily trigger high-frequency resonance and cause additional vibration and noise.

[0026] To this end, the present invention proposes a permanent magnet motor, which constrains the key parameters of the rotor structure to improve the rigidity of the rotor, effectively reduce the influence of centrifugal force and magnetic pull during high-frequency operation, meet customer market needs, and create a broadband compressor.

[0027] See also Figures 1 to 5 In one embodiment of the present invention, the permanent magnet motor includes a stator 100 and a rotor 200 .

[0028] The stator 100 includes a plurality of stator slots 110 uniformly distributed along the circumferential direction; the rotor 200 is arranged inside the stator 100, and a plurality of magnetic steel slot groups 210 are uniformly distributed along the circumference of the rotor 200, each magnetic steel slot group 210 corresponds to a magnetic pole; each magnetic steel slot group 210 includes at least two independent magnetic steel slots 220; adjacent magnetic steel slots 220 in the same magnetic steel slot group 210 are separated by an internal magnetic bridge 230; magnets 300 are arranged in all magnetic steel slots 220; wherein the maximum outer diameter of the rotor 200 is D1; ​​the same magnetic steel slot group 2 The sum of the lengths of the longest sides of the magnets 300 in the same magnetic steel slot group 210 on the cross section of the rotor 200 is L1, and the minimum side length of any magnet 300 in the same magnetic steel slot group 210 is L2; ​​the minimum width of the internal magnetic bridge 230 in the same magnetic steel slot group 210 in the direction perpendicular to the radial direction of the rotor 200 is A1; the minimum distance between the slot wall of the magnetic steel slot 220 away from the center of the rotor 200 and the outer contour of the rotor 200 in the same magnetic steel slot group 210 is A2; the number of stator slots 110 is Q, and the number of pole pairs of the rotor 200 is P; the relationship is satisfied: 1.5≤ ≤2.5, where GCD(Q,P) is the greatest common divisor of Q and P.

[0029] Reference Figure 1 and Figure 5Specifically, the stator 100 is composed of a stator core (including a yoke and teeth) and a stator winding. The yoke is an annular structure that provides a closed magnetic circuit path. The teeth are spaced apart circumferentially along the yoke and together with the yoke define stator slots 110 for placing the stator winding. When the stator winding is energized, it generates a rotating magnetic field, which interacts with the magnetic field of the rotor 200 to drive the motor to operate.

[0030] Reference Figures 1 to 4 The rotor 200 consists of a rotor core (equipped with magnetic steel slots 220, an inner magnetic bridge 230, and an outer magnetic bridge 240) and magnets 300. The magnetic steel slots 220 are evenly distributed along the outer circumference of the rotor 200. A plurality of magnetic steel slots 220 form magnetic steel slot groups 210 (two, three, or more). Each magnetic steel slot group 210 forms a magnetic pole (a multi-slot design can optimize magnetic field distribution). For example, two magnetic steel slot groups 210 are arranged in a V-shape or a straight line; for example, three magnetic steel slot groups 210 are arranged in a U-shape. Each magnetic pole is separated into at least two independent magnetic steel slots 220 by an inner magnetic bridge 230. The minimum width (A1) of the inner magnetic bridge 230 and the minimum distance (A2) from the magnetic steel slots 220 to the outer circumference of the rotor 200 form a rigid support structure that can directly resist the centrifugal force load during high-frequency rotation. Compared with the traditional single magnetic steel slot 220 design, the distributed layout of the inner magnetic bridge 230 avoids stress concentration and reduces the risk of rotor core cracking.

[0031] Reference Figure 1 、 Figure 2 and Figure 4 The sum of the lengths of the longest sides of the magnets 300 in the same magnetic steel slot group 210 on the cross section of the rotor 200 is L1. That is, if there are two magnets 300 in the same magnetic steel slot group 210, the longest sides of the two magnets 300 are a and b respectively, then L1=a+b. Figure 3 Similarly, if a magnetic steel slot group 210 includes three magnets 300, and the longest sides of the three magnets 300 are a, b and c respectively, then L1=a+b+c.

[0032] Reference Figures 1 to 4 The multiple magnetic steel slots 220 within the same magnetic steel slot group 210 are not connected to each other. Adjacent magnetic steel slots 220 are separated by internal magnetic bridges 230 (reinforcement ribs) to improve the radial strength of the rotor 200 and resist centrifugal forces. Magnetic steel slots 220 between different magnetic poles are separated by magnetic isolation bridges 260 to reduce magnetic flux leakage and improve magnetic circuit efficiency. In other words, adjacent magnetic steel slots 220 within adjacent magnetic steel slot groups 210 are not connected. A magnet 300 is placed in each magnetic steel slot 220, interacting with the stator magnetic field to generate torque.

[0033] The distance from the slot wall of the magnetic steel slot 220 in the same magnetic steel slot group 210 away from the center of the rotor 200 to the outer contour of the rotor 200 is the outer magnetic bridge 240 , that is, the minimum size of the outer magnetic bridge 240 is A2.

[0034] In this embodiment, a permanent magnet motor is used in a rotary rotor 200 compressor. The rotor core has an inner circle that cooperates with the crankshaft 410 of the pump assembly 400 in the compressor to transmit torque to the pump body (crankshaft 410, bearings, cylinder).

[0035] The technical solution of the present invention is to constrain the parameters 1.5≤ ≤2.5, balance structural strength and electromagnetic performance, refer to Figure 1 、 Figure 2 and Figure 4 The sum of the lengths of the longest sides of the magnets 300 in the same magnetic steel slot group 210 on the cross section of the rotor 200 is L1. That is, if there are two magnets 300 in the same magnetic steel slot group 210, the longest sides of the two magnets 300 are a and b respectively, then L1=a+b. Figure 3 Similarly, if there are three magnets 300, and the longest sides of the three magnets 300 are a, b and c respectively, then L1=a+b+c.

[0036] Reference Figures 1 to 4 The multiple magnetic steel slots 220 within the same magnetic steel slot group 210 are not connected to each other. Adjacent magnetic steel slots 220 are separated by internal magnetic bridges 230 (reinforcement ribs) to improve the radial strength of the rotor 200 and resist centrifugal forces. Magnetic steel slots 220 between different magnetic poles are separated by magnetic isolation bridges 260 to reduce magnetic flux leakage and improve magnetic circuit efficiency. In other words, adjacent magnetic steel slots 220 within adjacent magnetic steel slot groups 210 are not connected. A magnet 300 is placed in each magnetic steel slot 220, interacting with the stator magnetic field to generate torque.

[0037] The distance from the slot wall of the magnetic steel slot in the same magnetic steel slot group 210 away from the center of the rotor 200 to the outer contour of the rotor 200 is the outer magnetic bridge 240 , that is, the minimum size of the outer magnetic bridge 240 is A2.

[0038] In this embodiment, a permanent magnet motor is used in a rotary rotor 200 compressor. The rotor core has an inner circle that cooperates with the crankshaft 410 of the pump assembly 400 in the compressor to transmit torque to the pump body (crankshaft 410, bearings, cylinder).

[0039] molecular It is related to the effective volume of the magnet and the radial size of the rotor, and affects the torque output capacity of the motor; the denominator Reflects the "structural strength coefficient" of the rotor (A1 and A2 affect the mechanical strength, and the GCD value of the slot-pole combination affects the magnetic field stability).

[0040] Specifically, in rotary compressors, the primary consideration is the impact of centrifugal force on the mechanical strength of rotor 200 during operation. For rotor 200, the larger the outer diameter D1 of the rotor core, the greater the linear velocity of the outer circle during operation, and therefore, the higher the mechanical strength requirements for rotor 200. Permanent magnet motors utilize an internal magnetic circuit structure, with magnets 300 located within magnetic steel slots 220. The larger the dimensions L1 and L2 of magnets 300, the greater the stress on the outer side of the rotor core, thus affecting the rigidity of rotor 200. The rotor magnetic bridge (A1 (minimum distance between the inner magnetic bridge 230) and A2 (distance from the magnetic steel slots 220 to the outer circle)) enhances the mechanical strength of rotor 200. Furthermore, as the number of unit motors increases, rotor 200 becomes more stable during operation, and the amplitude of rotor 200 fluctuations and yaw decreases, contributing to the stable operation of rotor 200.

[0041] Reference Figure 7 In the relationship curve between rotor tensile strength and motor efficiency, the figure includes two curves, representing the relationship between rotor tensile strength and motor efficiency. The overall trend of the rotor tensile strength curve is that it first rises and then falls, and the overall trend of the motor efficiency curve is that it first falls and then rises. Figure 7 As can be seen from the figure, when the relationship is less than 1.5, although the rotor's mechanical strength is greatly improved, as the width of the magnetic bridge increases and the number of unit motors increases, the magnet leakage also increases significantly, resulting in reduced magnet utilization and motor efficiency, which in turn affects motor performance. When the relationship is greater than 2.5, the mechanical strength and rigidity are insufficient. At high speeds, the magnetic bridge may break, the stator and rotor may become stuck, and the compressor may fail.

[0042] To this end, this relationship can balance the relationship between centrifugal force and motor cost-effectiveness, achieving optimal motor design. Specifically, this solution quantifies the ratio of "electromagnetic performance" to "structural strength" through a formula (constrained to 1.5-2.5), providing a clear basis for parameter selection in the design: If the ratio is too small (<1.5), the structural strength is excessive but the electromagnetic performance is insufficient (torque output is limited); that is, when the relationship is less than 1.5, although the mechanical strength of the rotor is greatly improved, as the size of the magnetic bridge (A1 and A2) increases and the number of unit motors increases, the magnet leakage flux will also increase significantly, resulting in reduced magnet utilization and motor efficiency, which in turn affects motor performance.

[0043] If the ratio is too large (>2.5), the electromagnetic performance is strong but the structural strength is insufficient (easy to deform at high frequencies); that is, when the relationship is greater than 2.5, the mechanical strength rigidity is insufficient. When running at high speed, the magnetic bridge (A1 and A2) is small in size and may break, causing the stator and rotor to get stuck, and the compressor to fail.

[0044] In this way, the above relationship can balance the relationship between centrifugal force and motor cost-effectiveness, achieving the optimal motor design. Specifically, in traditional motor design, the balance between electromagnetic performance and structural strength relies on empirical trial and error, lacking clear quantitative standards. However, by constraining the relevant parameters within a reasonable ratio, "high rigidity, low interference, and broadband operation" can be achieved. This eliminates the need for repeated iterative verification and allows the optimal solution to be quickly locked in by adjusting parameters such as D1, L1, L2, A1, and A2. This ensures that motor products of different batches and specifications meet the unified performance standards of broadband compressors, reducing R&D costs and the risk of quality fluctuations.

[0045] Combine Figure 6 Furthermore, the rotor 200 includes a rotor core, the axial height of the rotor core is H, the stator 100 includes a stator core, the minimum inner diameter of the stator core is D2, and the relationship is satisfied: 21≤ ≤30. In rotary compressors, the effect of magnetic pull on rotor 200 rigidity during operation must be considered. A larger rotor 200 pole pair number P increases the motor's magnetic load and, consequently, the radial magnetic pull. The total radial magnetic pull is the integral of stress on the air gap surface. Therefore, larger rotor 200 outer diameter D1 and rotor core height H increase the air gap surface area and, consequently, the radial magnetic pull. The stator 100's armature and the rotor 200 magnetic field interact in the air gap. Therefore, a larger air gap length (D2 - D1) / 2 reduces the interacting radial magnetic pull, thereby minimizing deformation.

[0046] Reference Figure 8 In the curve showing the relationship between rotor magnetic pull and maximum output torque, the rotor magnetic pull generally shows a downward trend, with a rapid decline in the early stages and a plateau in the later stages. The maximum output torque generally shows an upward trend, with a rapid rise in the early stages and a plateau in the later stages. When the relationship is less than 21, the motor's radial magnetic pull is low, ensuring that the magnetic pull does not affect shaft deformation. However, the rotor magnetic load or the rotor air gap surface area decreases, or the air gap length increases, resulting in a decrease in the motor's maximum output torque capacity. When the relationship is greater than 30, the rotor volume is large, the magnetic load is high, and the air gap length is short, resulting in high magnetic pull. This, in turn, increases the impact of radial magnetic pull on shaft rigidity deformation, severely causing shaft deformation, wear of pump components, and stator and rotor bore scuffing.

[0047] About the measurement of various parameter dimensions.

[0048] The starting and ending points of the rotor 200's maximum outer diameter (D1) are based on the rotor core's effective cylindrical surface (ignoring any undesigned defects). Four evenly distributed points (0°, 90°, 180°, and 270°) are measured along the circumference of the rotor core's axial end faces. The diameters of all these points are recorded, and the maximum value is taken as D1. If there are undesigned pits or protrusions (such as depressions caused by impact), re-measure points outside the defective area. If the rotor 200's outer edge has grooves, avoid the grooves during measurement and only take the diameter of the complete cylindrical surface.

[0049] The side length of the magnet 300 is the geometric dimension of the magnet 300 within the magnetic steel slot 220 in the cross-section (perpendicular to the axial direction) of the rotor 200. In cross-section, the magnet 300 is a rectangle with long and short sides. Use a vernier caliper or other tool to measure the length of the outline of the magnet 300. If there are two magnets 300 in the same magnetic steel slot 220, measure the longest sides of both magnets 300 in cross-section. Assume they are a and b, then L1 = a + b. If the shortest sides of the two magnets 300 have different values, take the average value. If the edge of the magnet 300 has a slight chamfer (process requirement), ignore the chamfer and measure the side length of the main body.

[0050] The minimum width (A1) of the internal magnetic bridge 230 is the minimum distance between adjacent magnetic slots 220 within the same magnetic slot group 210, perpendicular to the rotor 200 radial direction (i.e., the width of the bridge at its narrowest point). Use a caliper or other tool to locate the narrowest point of the internal magnetic bridge 230 on the cross section of the rotor 200. Measure the distance perpendicular to the direction of the bridge extension, starting and ending at the inner wall edges of the magnetic slots 220 on either side. Take the minimum value from three different cross-sections as A1. If the magnetic bridge has machining marks or localized indentations, use the theoretical design outline as a reference.

[0051] The minimum distance (A2) from the magnetic steel slot 220 to the outer circle is the shortest radial distance from the slot wall (outer slot wall) of the magnetic steel slot 220 away from the center of the rotor 200 to the outer circle of the rotor 200. A polar coordinate system is established with the center of the rotor 200 as the origin. The radial distance from each point on the outer slot wall to the outer circle is measured. The minimum value is A2. If the distance is too short due to a local protrusion on the outer circle (not a design requirement), this point is not included in the calculation, and the minimum value of the remaining area is used.

[0052] The axial height (H) of the rotor 200 is the effective height of the rotor 200 along its axis. The distance between the two reference surfaces is measured axially, using the two end surfaces of the rotor core as the reference planes (if the end surfaces are chamfered, the plane at the root of the chamfer is used). The height is measured at three points evenly spaced around the circumference, and the average value is used as H. If a designed internal step structure (such as a shaft shoulder) is included, only the height of the core portion (excluding the shaft shoulder) is measured.

[0053] The minimum inner diameter (D2) of the stator core is the minimum diameter of the inner contour of the stator 100, excluding any internal design features such as slots. Measure the inner diameter at four evenly spaced points on both axial ends of the stator 100, avoiding slots. Record all measurements and use the minimum value as D2.

[0054] Furthermore, the rotor core has an axial hole 250 for transmission connection, and the minimum inner diameter of the axial hole 250 is D3, 0.5≤ ≤0.9. This formula performs dimensionless processing, substituting all physical quantities (D3, D1, H) into the formula with their numerical values ​​(based on the specified units). The units in the formula are ignored, and only the numerical values ​​are used when all quantities are substituted, that is, only numerical calculations are performed.

[0055] In a rotary compressor, the crankshaft 410 in the pump body assembly 400 is connected to the shaft hole 250 of the rotor 200. When the shaft hole 250 of the rotor core is larger, that is, D3 is larger, the shaft diameter of the crankshaft 410 is correspondingly larger, and the ability to resist deformation is stronger, that is, the minimum inner diameter D3 of the shaft hole 250 (the diameter of the hole in the center of the rotor for installing the output shaft, which must meet the interference fit or key connection strength requirements with the external drive shaft); when the outer diameter D1 of the rotor 200 is larger, the centrifugal force during operation of the rotor 200 is greater, and the risk of deformation of the pump body shaft system is also greater; since the rotary rotor compressor is a single cantilever beam structure, when the axial height H of the rotor core is larger, the amplitude of swing away from the bearing end is also larger, and the risk of stator and rotor bore scraping increases; when the greatest common divisor GCD(Q,P) of the number of poles and the number of slots is larger, that is, the number of unit motors increases, the magnetic load increases, and the radial magnetic pull increases accordingly, which in turn affects the deformation of the shaft system.

[0056] Reference Figure 9 In the relationship curve between shaft rigidity and compressor energy efficiency, shaft rigidity generally shows an upward trend. Compressor energy efficiency generally shows a downward trend. When the relationship is less than 0.5, the pump shaft rigidity is insufficient, and its ability to resist centrifugal and magnetic forces does not meet actual operational requirements. When the relationship is greater than 0.9, increasing the crankshaft outer diameter can improve shaft rigidity. However, a larger crankshaft outer diameter increases pump frictional mechanical losses and a greater decrease in energy efficiency.

[0057] Specifically, the units of L1, L2, H, D1, D2, D3, A1 and A2 are mm.

[0058] Specifically, 15≤Q≤18, such as 15, 16, 17, 18.

[0059] Specifically, 5≤P≤6, such as 5, 6.

[0060] The restriction of 15≤Q≤18, 5≤P≤6 further limits the protection range to specific pole-slot combinations of 15 / 16 / 17 / 18 slots and 10 or 12 poles. In this case, the value range of GCD(Q,P) is uniquely determined. For example, a motor with 15 slots and 10 poles or 18 slots and 12 poles can be used.

[0061] Specifically, 5≤GCD(Q,P)≤6.

[0062] To balance production cycle time with the capacity of winding equipment, a motor solution with a fractional number of slots per pole per phase is required. Furthermore, considering the need to reduce noise and vibration in multi-slot motors, the harmonic suppression characteristics of fractional slots are utilized to balance vibration resistance and lightweighting. Specifically, the motor has m phases and q slots per pole per phase, where q = Q / 2mP, where 0 < q < 1. The motor uses fractional-slot concentrated windings (e.g., q = 0.25, 0.5, etc.), rather than integer-slot distributed windings.

[0063] For material cost and lightweight optimization, specifically, 0.3 mm ≤ A1 ≤ 0.7 mm, specifically, 50 mm ≤ D1 ≤ 90 mm.

[0064] The present invention further provides a compressor comprising a permanent magnet motor and a pump assembly 400. The specific structure of the permanent magnet motor is similar to that of the aforementioned embodiments. Since the present compressor utilizes all of the technical solutions of all of the aforementioned embodiments, it at least possesses all of the beneficial effects provided by the technical solutions of the aforementioned embodiments, and therefore, no further description is given herein. The pump assembly 400 includes a crankshaft 410, which is in transmission engagement with the rotor 200.

[0065] The pump body assembly 400 further includes a cylinder and a piston that performs rotational compression in the cylinder. The piston is connected to the rotor 200 via a crankshaft 410 to drive the piston to rotate eccentrically during the rotation of the rotor 200.

[0066] The present invention also provides a refrigeration device comprising the compressor as described above.

[0067] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. A permanent magnet motor, characterized in that: include: A stator comprising a plurality of stator slots uniformly distributed along a circumferential direction; and A rotor, the rotor being disposed inside the stator, the rotor having a plurality of magnetic steel slot groups evenly distributed in the circumferential direction thereof, each magnetic steel slot group corresponding to a magnetic pole; each magnetic steel slot group including at least two magnetic steel slots; adjacent magnetic steel slots within the same magnetic steel slot group being separated by an internal magnetic bridge; and magnets being disposed in all magnetic steel slots; The maximum outer diameter of the rotor is D1; ​​the sum of the lengths of the longest sides of the magnets in the same magnetic steel slot group on the rotor cross section is L1, and the minimum side length of any magnet in the same magnetic steel slot group is L2; ​​the minimum width of the internal magnetic bridge in the same magnetic steel slot group in the direction perpendicular to the rotor radial direction is A1; the minimum distance from the slot wall of the magnetic steel slot in the same magnetic steel slot group away from the center of the rotor to the outer contour of the rotor is A2; the number of stator slots is Q, and the number of pole pairs of the rotor is P; the relationship is satisfied: 1.5≤ ≤2.5, where GCD(Q,P) is the greatest common divisor of Q and P.

2. The permanent magnet motor according to claim 1, characterized in that The axial height of the rotor is H, and the minimum inner diameter of the stator is D2, satisfying the relationship: 21≤ ≤30.

3. The permanent magnet motor according to claim 2, characterized in that: The rotor has a shaft hole for transmission connection, and the minimum inner diameter of the shaft hole is D3, 0.5≤ ≤0.

9.

4. The permanent magnet motor according to any one of claims 1 to 3, characterized in that 15≤Q≤18。 5. The permanent magnet motor according to any one of claims 1 to 3, characterized in that: 5≤P≤6。 6. The permanent magnet motor according to any one of claims 1 to 3, characterized in that The number of phases of the motor is m, the number of slots per pole per phase is q, q=Q / 2mP, wherein 0<q<1.

7. The permanent magnet motor according to any one of claims 1 to 3, characterized in that 5≤GCD(Q,P)≤6.

8. The permanent magnet motor according to any one of claims 1 to 3, characterized in that: 0.3mm≤A1≤0.7mm.

9. The permanent magnet motor according to any one of claims 1 to 3, characterized in that 50mm≤D1≤90mm.

10. A compressor, characterized in that: It comprises the permanent magnet motor and pump body assembly according to any one of claims 1 to 9, wherein the pump body assembly comprises a crankshaft, and the crankshaft is in driving cooperation with the rotor.

11. A refrigeration device, characterized in that: Comprising the compressor of claim 10.

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