Permanent magnet motor and scroll compressor

Abstract

The application provides a kind of permanent magnet motor and scroll compressor, it is related to scroll compressor design and manufacturing field.Permanent magnet motor includes stator core and rotor core, stator core outside radius R1 satisfies 70mm≤R1≤80mm, it is composed of tooth portion, yoke portion and slot portion.Rotor core outside is alternately constituted by multiple groups of first circular arc and two sides symmetrical second circular arc, first circular arc quantity is P, second circular arc quantity is 2×P, first circular arc and second circular arc are eccentric, first circular arc center, second circular arc center and the intersection point of the two are collinear.Three points are collinear.Rotor core inside is equipped with evenly distributed magnetic steel placement slot, magnetic steel placement slot outside is composed of middle first linear segment and two sides second linear segment, magnetic steel placement slot side and second linear segment are connected by magnetic bridge circular arc, magnetic bridge circular arc center is same with second circular arc, and magnetic steel placement slot is internally provided with polarity-alternating magnetic steel.

Description

Technical Field

[0001] This invention relates to the field of compressor design and manufacturing, and more particularly to a permanent magnet motor and a scroll compressor. Background Technology

[0002] Compared to other types of compressors, scroll compressors offer advantages such as high reliability, high efficiency and energy saving, and compact structure, and are widely used in refrigeration, commercial air conditioning, and automotive air conditioning. The motor, as its core drive component, directly determines the system's operating characteristics. Permanent magnet motors, due to their high efficiency and wide operating range, are gradually becoming the mainstream drive for scroll compressors.

[0003] Traditional scroll compressors often use permanent magnet motors with general motor structures in the design phase, without analyzing and optimizing for the load characteristics, torque requirements, and casing diameter of the scroll compressor. This results in a disconnect between the motor stator core outer diameter, number of slots, magnetic poles, and other parameters and the actual operating conditions of the compressor. The motor output power is higher than the actual power required by the compressor, resulting in power excess and a "powered motor for a small load" phenomenon. This contradicts the inherent advantage of high power density of permanent magnet motors and seriously restricts the overall performance and economy of the machine.

[0004] Currently, permanent magnet motors commonly use stator skew and rotor skew to reduce torque ripple. While these methods can reduce torque ripple to some extent, skew increases the difficulty of winding, while skew has complex manufacturing processes, high assembly precision requirements, and poor consistency in mass production. Furthermore, using stator skew or rotor skew will significantly reduce the output torque.

[0005] The electromagnetic noise level of a permanent magnet motor directly determines the overall operating quality of the compressor and the customer experience. In traditional design approaches, the industry generally uses methods such as increasing the air gap length and increasing the stator yoke thickness to suppress electromagnetic noise. Although these methods can reduce air gap magnetic flux density harmonics and electromagnetic force waves to some extent, they increase the amount of materials used and exacerbate the mismatch between the motor and the compressor, resulting in a "large motor pulling a small load" problem.

[0006] In summary, traditional permanent magnet motors used in scroll compressors suffer from multiple problems, including poor power matching, limited torque ripple optimization methods, and a single electromagnetic noise suppression approach. These issues prevent the full utilization of the inherent advantages of high power density and energy efficiency of permanent magnet motors. Furthermore, the complex manufacturing process, redundant materials, and parameter misalignment increase costs, making it difficult to meet the core requirements of refrigeration, commercial air conditioning, and automotive air conditioning industries for high efficiency, low noise, compactness, and reliability. This severely limits the improvement of overall machine performance and market competitiveness. Targeted innovative designs at the structural topology and parameter coordination levels are needed to overcome these technological bottlenecks. This invention aims to provide a permanent magnet motor to address these shortcomings. Summary of the Invention

[0007] In view of the technical problems mentioned above, such as unreasonable power matching, limited means of torque pulsation optimization, and low material utilization due to electromagnetic noise suppression in existing permanent magnet motors for scroll compressors, this invention provides a permanent magnet motor and scroll compressor. By rationally designing the dimensions, structure, and layout of the stator core, rotor core outline, magnet placement slot, and magnetic isolation bridge, the technical objectives of reducing torque pulsation, suppressing electromagnetic noise, and reducing material usage are achieved.

[0008] The technical means employed in this invention are as follows: A permanent magnet motor includes a stator core and a rotor core; The maximum distance from the outer side of the stator core to the center Oa of the permanent magnet motor is R1, satisfying: 70mm≤R1≤80mm. The stator core includes a tooth section, a yoke section, and a slot section between the tooth section and the yoke section. The inner side of the tooth section is a tooth arc, the center of the tooth arc is Oa, the radius of the tooth arc is R2, the number of slot sections is Z, and the maximum distance from the outer side of the slot section to the center Oa of the permanent magnet motor is Ls. The outer side of the rotor core includes multiple sets of evenly distributed first arc segments alternately connected with symmetrical second arc segments on both sides. The number of first arc segments is P, the number of second arc segments is 2P, the center of the first arc segment is Oa, the radius of the first arc segment is R3, the midpoint of the first arc segment is C, the center of the second arc segment is Ob, the radius of the second arc segment is R4, the first arc segment intersects with the second arc segment on the adjacent side at D, Oa, Ob and D are collinear, and the angle between the line segment formed by Oa to C and the line segment formed by Ob to D is θ. Multiple evenly distributed magnet placement slots are opened on the inner side of the rotor core. The outer side of the magnet placement slot is composed of a first straight segment in the middle and second straight segments on both sides. The length of the first straight segment is wb, and the length of the second straight segment is w1. The side of the magnet placement slot and the second straight segment are connected by a magnetic bridge arc. The center of the magnetic bridge arc is the same as that of the second arc. The distance between the magnetic bridge arc and the second arc is hb. The magnet placement slot contains magnets with alternating polarity, and the number of magnets is equal to the number of magnet placement slots. Let L0 = (R3 - R4) × sinθ, L1 = L2= L3 = R3 - (L1 + L2), L4 = 0.5 × (R1 + Ls) - R2, L5 = 2 × π × (L4 + R2) / Z, satisfying: 2.22 < (L5 - L4) / L3 < 3.09.

[0009] Furthermore, the number of magnet placement slots is equal to the number of the first arc segment, and satisfies the following condition with the number of slots: 6≤ZP / 2≤10.

[0010] Furthermore, the angle θ between the line segment from Oa to C and the line segment from Ob to D satisfies: 0.8°≤θ≤3.5°.

[0011] Furthermore, the maximum distance R1 between the outer side of the stator core and the center Oa of the permanent magnet motor, the maximum distance Ls between the outer side of the slot and the center Oa of the permanent magnet motor, the radius R2 of the tooth arc, and the radius R3 of the first arc segment satisfy: 1.476 < (R1 + Ls) / (R2 + R3) < 1.695.

[0012] Furthermore, the radius R2 of the tooth arc and the radius R3 of the first arc segment satisfy: 0.5mm≤R2-R3≤1.2mm.

[0013] Furthermore, the two toothed sides are parallel, and the distance between the two toothed sides is ws, which satisfies the following condition with the length wb of the first straight segment: 1.96 < wb / ws < 2.24.

[0014] Furthermore, the two slot opening sides are parallel, the distance between the two slot opening sides is wk, the inner side of the magnet placement slot is parallel to the first straight segment, and the distance between the inner side of the magnet placement slot and the first straight segment is hm, satisfying: 1.58 < wk / hm < 2.03.

[0015] Furthermore, the lengths of L0 and the secondary straight segment w1 satisfy: .

[0016] Furthermore, the maximum distance R1 from the outer side of the stator core to the center Oa of the permanent magnet motor, the maximum distance Ls from the outer side of the slot to the center Oa of the permanent magnet motor, the radius R3 of the first arc segment, and the radius R4 of the second arc segment satisfy 1.432 < (R3-R4) / (R1-Ls) < 1.876.

[0017] The present invention also provides a scroll compressor, including the aforementioned permanent magnet motor.

[0018] Compared with the prior art, the present invention has the following advantages: By integrating the multi-segment arc structure of the rotor core, the magnet placement slots, and the magnetic isolation bridge, and constraining the key dimensions of the stator core, the air gap magnetic flux density distribution can be optimized without the need for skewed slots or poles, reducing torque pulsation and suppressing electromagnetic noise. Simultaneously, it avoids material waste caused by increasing the air gap and thickening the stator core yoke, effectively solving the power mismatch problem. While improving operational stability and quietness, it reduces material usage and lowers production costs, enabling a high degree of compatibility between the motor and the scroll compressor, comprehensively improving the overall economy and reliability of the machine. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the permanent magnet motor of the present invention.

[0021] Figure 2 This is a schematic diagram of the stator core structure of the present invention.

[0022] Figure 3 for Figure 1 A magnified view of part A in the image.

[0023] Figure 4 for Figure 1 A magnified view of part B in the image.

[0024] Figure 5 This is a comparison diagram of torque pulsation between the permanent magnet motor using the present invention and existing technologies.

[0025] Figure 6 This is a comparison chart of the radiated sound power of the permanent magnet motor using the present invention and existing technologies.

[0026] Figure 7 This is a comparison chart of the cost of electromagnetic materials used in the permanent magnet motor of this invention and existing technologies.

[0027] In the diagram: 1. Permanent magnet motor; 11. Stator core; 111. Tooth section; 1111. Tooth section arc; 1112. Tooth section side; 112. Yoke section; 113. Slot section; 1131. Slot section opening side; 12. Rotor core; 121. First section arc; 122. Second section arc; 123. Magnet placement slot; 1231. First section straight segment; 1232. Second section straight segment; 1233. Magnet placement slot side; 1234. Magnet isolation bridge arc; 1235. Magnet placement slot inner edge; 124. Magnet. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0032] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the present invention provides a permanent magnet motor, including a stator core 11 and a rotor core 12; the maximum distance from the outer side of the stator core 11 to the center Oa of the permanent magnet motor 1 is R1, satisfying 70mm≤R1≤80mm. The stator core 11 includes a tooth portion 111, a yoke portion 112, and a slot portion 113 between the tooth portion 111 and the yoke portion 112. The inner side of the tooth portion 111 is a tooth arc 1111, the center of the tooth arc 1111 is Oa, and the radius of the tooth arc 1111 is... R2, the number of slots 113 is Z, and the maximum distance from the outer side of slot 113 to the center Oa of the permanent magnet motor is Ls; the outer side of the rotor core 12 is composed of multiple sets of evenly distributed first arc segments 121 and symmetrically arranged second arc segments 122 on both sides of the first arc segment 121, alternatingly connected. The number of first arc segments 121 is P, the number of second arc segments 122 is 2P, the center of the first arc segment 121 is Oa, the radius is R3, the midpoint of the first arc segment 121 is C, and the center of the second arc segment 122 is... Ob, with radius R4, the first arc 121 intersects the adjacent second arc 122 at point D. Points Oa, Ob, and D are collinear, and the angle between the line segment formed by Oa to C and the line segment formed by Ob to D is θ. Multiple evenly distributed magnet placement slots 123 are opened inside the rotor core 12. The outer side of the magnet placement slots 123 consists of a first straight segment 1231 located in the middle and second straight segments 1232 located on both sides. The length of the first straight segment 1231 is wb, and the length of the second straight segments... The length of segment 1232 is w1. The side 1233 of the magnet placement slot is connected to the straight segment 1232 by a magnetic isolation bridge arc 1234. The center of the magnetic isolation bridge arc 1234 is the same as that of the arc 122 of the second segment, and the distance between the magnetic isolation bridge arc 1234 and the arc 122 of the second segment is hb. The magnet placement slot 123 contains magnets 124 with alternating polarity, and the number of magnets 124 is equal to the number of magnet placement slots 123. Let L0 = (R3 - R4) × sinθ, L1 = L2= L3 = R3 - (L1 + L2), L4 = 0.5 × (R1 + Ls) - R2, L5 = 2 × π × (L4 + R2) / Z, satisfying: 2.22 < (L5 - L4) / L3 < 3.09.

[0033] By implementing the above limitations, torque ripple can be effectively reduced, power density increased, material usage reduced, and costs lowered.

[0034] Preferably, the number of magnet placement slots 123 is equal to the number of the first arc 121, and the number of slots 113 satisfies 6≤ZP / 2≤10. Through reasonable pole-slot matching, cogging torque and electromagnetic vibration noise can be effectively reduced, and operational stability can be improved.

[0035] Preferably, the angle θ between the line segment Oa to C and the line segment Ob to D satisfies 0.8°≤θ≤3.5°. By making the air gap non-uniform, the harmonic content of the air gap is reduced, thereby reducing torque pulsation and suppressing electromagnetic noise.

[0036] Preferably, R1, Ls, R2, and R3 satisfy the condition 1.476 < (R1 + Ls) / (R2 + R3) < 1.695. This limitation allows for a more reasonable matching of stator and rotor dimensions, improves magnetic circuit utilization, and achieves better power matching.

[0037] Preferably, the radius R2 of the tooth arc 1111 and the radius R3 of the first arc 121 satisfy 0.5mm≤R2-R3≤1.2mm. This ensures a reasonable air gap size while balancing material utilization and noise reduction.

[0038] Preferably, the two tooth sides 1112 are parallel, and the distance between the two tooth sides 1112 is ws, which satisfies 1.96 < wb / ws < 2.24 with the length wb of the first straight segment 1231. This makes the stator tooth 111 more coordinated with the polar arc coefficient and reduces magnetic field distortion.

[0039] Preferably, the two opening sides 1131 of the two slots are parallel, the distance between the two opening sides 1131 of the two slots is wk, the inner side 1235 of the magnet placement slot is parallel to the first straight section 1231, and the distance between them is hm, satisfying 1.58 < wk / hm < 2.03.

[0040] Preferably, L0 and the length w1 of the second straight segment 1232 satisfy the following conditions: .

[0041] Preferably, the maximum distance from the outer side of the stator core 11 to the center Oa of the permanent magnet motor 1 is R1, the maximum distance from the outer side of the slot 113 to the center Oa of the permanent magnet motor is Ls, the radius R3 of the first arc 121, and the radius R4 of the second arc 122 satisfy 1.432 < (R3-R4) / (R1-Ls) < 1.876. This can further optimize the compatibility between the rotor core profile and the stator structure.

[0042] By limiting the structure and parameters described above, torque pulsation can be effectively reduced, electromagnetic noise can be suppressed, material usage can be reduced, and the matching between the motor and the scroll compressor can be improved.

[0043] Some parameters in this embodiment are shown in the table below:

[0044] It should be noted that "prior art" as used below refers to technology that does not meet any one or more of the limitations in the table above.

[0045] The following explanation will be based on a scroll compressor with R290 refrigerant and a displacement of 81cc.

[0046] like Figure 5 The image shows a comparison of torque ripple between the permanent magnet motor of this invention and existing technologies. Figure 5As can be seen, the torque ripple of the permanent magnet motor with the optimized structure and parameters of this invention is reduced from 11.97% to 5.68%, a significant reduction. This can effectively improve the quality of output torque, significantly enhance the stability and reliability of the whole machine operation, reduce the risk of mechanical wear and structural fatigue, and extend the service life of the compressor.

[0047] like Figure 6 The image shows a comparison of the radiated sound power of the permanent magnet motor using this invention and existing technologies. Figure 6 As can be seen, by optimizing the air gap magnetic flux density harmonics and suppressing electromagnetic force waves, this invention can significantly reduce the electromagnetic noise of the motor, improve the quietness of compressor operation and enhance the user experience.

[0048] like Figure 7 The image shows a cost comparison chart of electromagnetic materials used in the permanent magnet motor of this invention and existing technologies. Figure 7 As can be seen, this invention reduces the amount of electromagnetic materials used through structural optimization, lowering the cost of electromagnetic materials per motor from 298 yuan to 243 yuan, a reduction of 18.5%. This achieves improved performance while reducing costs.

[0049] In addition, the present invention also provides a scroll compressor that uses the aforementioned permanent magnet motor 1. Other structures and operations of the permanent magnet motor and the scroll compressor are known to those skilled in the art and will not be described in detail here.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A permanent magnet motor, characterized in that, Including stator core and rotor core; The maximum distance from the outer side of the stator core to the center Oa of the permanent magnet motor is R1, satisfying: 70mm≤R1≤80mm. The stator core includes a tooth section, a yoke section, and a slot section between the tooth section and the yoke section. The inner side of the tooth section is a tooth arc, the center of the tooth arc is Oa, the radius of the tooth arc is R2, the number of slot sections is Z, and the maximum distance from the outer side of the slot section to the center Oa of the permanent magnet motor is Ls. The outer side of the rotor core includes multiple sets of evenly distributed first arc segments alternately connected with symmetrical second arc segments on both sides. The number of first arc segments is P, the number of second arc segments is 2P, the center of the first arc segment is Oa, the radius of the first arc segment is R3, the midpoint of the first arc segment is C, the center of the second arc segment is Ob, the radius of the second arc segment is R4, the first arc segment intersects the second arc segment on the adjacent side at D, Oa, Ob and D are collinear, and the angle between the line segment formed by Oa to C and the line segment formed by Ob to D is θ; the angle θ between the line segment from Oa to C and the line segment from Ob to D satisfies: 0.8°≤θ≤3.5°; The maximum distance R1 from the outer side of the stator core to the center Oa of the permanent magnet motor, the maximum distance Ls from the outer side of the slot to the center Oa of the permanent magnet motor, the radius R2 of the tooth arc, and the radius R3 of the first arc segment satisfy: 1.476 < (R1 + Ls) / (R2 + R3) < 1.695; Multiple evenly distributed magnet placement slots are opened on the inner side of the rotor core. The outer side of the magnet placement slot is composed of a first straight segment in the middle and second straight segments on both sides. The length of the first straight segment is wb, and the length of the second straight segment is w1. The side of the magnet placement slot and the second straight segment are connected by a magnetic bridge arc. The center of the magnetic bridge arc is the same as that of the second arc. The distance between the magnetic bridge arc and the second arc is hb. The magnet placement slot contains magnets with alternating polarity, and the number of magnets is equal to the number of magnet placement slots. Let L0 = (R3 - R4) × sinθ, L1 = L2= L3 = R3 - (L1 + L2), L4 = 0.5 × (R1 + Ls) - R2, L5 = 2 × π × (L4 + R2) / Z, satisfying: 2.22 < (L5 - L4) / L3 < 3.

09.

2. The permanent magnet motor according to claim 1, characterized in that, The number of magnet placement slots is equal to the number of the first arc segment, and satisfies the following condition with the number of slots: 6≤ZP / 2≤10.

3. The permanent magnet motor according to claim 1, characterized in that, The radius R2 of the tooth arc and the radius R3 of the first arc segment satisfy: 0.5mm≤R2-R3≤1.2mm.

4. The permanent magnet motor according to claim 1, characterized in that, The two toothed sides are parallel, and the distance between the two toothed sides is ws, which satisfies the following condition with the length wb of the first straight segment: 1.96 < wb / ws < 2.

24.

5. The permanent magnet motor according to claim 4, characterized in that, The two slot openings are parallel, and the distance between the two slot openings is wk. The inner edge of the magnet placement slot is parallel to the first straight segment, and the distance between the inner edge of the magnet placement slot and the first straight segment is hm, satisfying: 1.58 < wk / hm < 2.

03.

6. The permanent magnet motor according to claim 1, characterized in that, The L0 and the length w1 of the secondary straight segment satisfy: .

7. The permanent magnet motor according to claim 1, characterized in that, The maximum distance R1 from the outer side of the stator core to the center Oa of the permanent magnet motor, the maximum distance Ls from the outer side of the slot to the center Oa of the permanent magnet motor, the radius R3 of the first arc segment, and the radius R4 of the second arc segment satisfy 1.432 < (R3-R4) / (R1-Ls) < 1.

876.

8. A scroll compressor, characterized in that, Includes the permanent magnet motor as described in any one of claims 1-7.

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