Rotor assembly, motor and compressor
By alternately setting rare earth permanent magnets and non-rare earth permanent magnets in the rotor assembly and optimizing their arrangement angle, the problem of insufficient utilization of rare earth resources in rare earth permanent magnet motors is solved, and the effect of reducing the amount of rare earth permanent magnets while ensuring that the motor performance remains unchanged.
Patent Information
- Application Number
- CN202421730789.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-07-19
AI Technical Summary
Due to limited rare earth resources, how to reduce the amount of rare earth permanent magnets while ensuring the unchanged motor performance has become a research hotspot.
By alternately arranging the rare earth permanent magnet first magnet and the non-rare earth permanent magnet second magnet in the rotor assembly and optimizing their arrangement angle in the rotor core, it is ensured that the width direction of the first magnet and the second magnet are at a certain angle with the radial and circumferential direction of the rotor core, thereby improving the utilization rate and magnetic flux of the magnet.
While ensuring that the performance of the permanent magnet motor remains unchanged, by optimizing the motor structure, the amount of rare earth permanent magnets is reduced and the magnetic flux and efficiency of the motor is improved.
Smart Images
Figure CN222802616U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motors, in particular to a rotor assembly, a motor and a compressor. Background Art
[0002] At present, permanent magnet motors have the advantages of simple structure, reliability, high efficiency and high power density, and are widely used. Among them, thanks to the high magnetic energy product of rare earth permanent magnets, the performance of rare earth permanent magnet motors is excellent. However, the reserves of rare earth resources are very limited, and the home appliance manufacturing industry should actively respond to the national call to reduce its dependence on rare earth permanent magnets. Completely replacing rare earth permanent magnets with non-rare earth permanent magnets will cause serious deterioration in motor performance. Therefore, the mixed use of rare earth permanent magnets and non-rare earth permanent magnets has become an important research direction, which can greatly reduce the amount of rare earth permanent magnets while ensuring the high performance of permanent magnet motors. Among them, how to further expand the reduction of rare earth permanent magnets through motor structure optimization design has become a current research hotspot. Utility Model Content
[0003] The main purpose of the utility model is to provide a rotor assembly, a motor and a compressor, aiming to provide a motor that reduces the amount of rare earth permanent magnets while ensuring the high performance of the permanent magnet motor.
[0004] To achieve the above-mentioned purpose, the rotor assembly proposed by the utility model comprises:
[0005] a rotor core; and,
[0006] A plurality of first magnets and a plurality of second magnets are alternately arranged in the rotor core along the circumferential direction of the rotor core, two ends of each of the first magnets and each of the second magnets in the length direction are arranged along the axial direction of the rotor core, two side ends of each of the first magnets in the width direction are arranged along the radial direction of the rotor core, and two ends of each of the second magnets in the width direction are arranged along the circumferential direction of the rotor core;
[0007] Among them, the first angle between the line connecting the center of the first magnet and the center of the rotor core and the width direction of the first magnet is α, the second angle between the line connecting the center of the second magnet and the center of the rotor core and the width direction of the second magnet is β, and at least one of α and |β-90°| is set to be greater than 0°.
[0008] In one embodiment, at least one of α and |β-90°| is set to be greater than or equal to 5°.
[0009] In one embodiment, α≤60° and / or |β-90°|≤30°.
[0010] In one embodiment, the plurality of first magnets are centrally symmetrically arranged about the center of the rotor core; and / or,
[0011] The plurality of second magnets are centrally symmetrically arranged about the center of the rotor core.
[0012] In one embodiment, the maximum magnetic energy product of the first magnet is set to be greater than the maximum magnetic energy product of the second magnet.
[0013] In one embodiment, the material of the first magnet is set to be a rare earth permanent magnet; and / or,
[0014] The material of the second magnet is set to be ferrite.
[0015] In one embodiment, the magnetization direction of the first magnet is arranged to be consistent with the thickness direction of the first magnet; and / or,
[0016] The magnetization direction of the second magnet is arranged to be consistent with the thickness direction of the second magnet.
[0017] In one embodiment, the two adjacent first magnets have magnetic poles at opposite ends having the same polarity.
[0018] In one embodiment, the magnetic pole polarity of one end of the second magnet close to the outer side of the rotor core is the same as the magnetic pole polarity of one end of two adjacent first magnets that are opposite to each other.
[0019] The utility model also provides a motor, the motor comprising a rotor assembly, the rotor assembly comprising:
[0020] a rotor core; and,
[0021] A plurality of first magnets and a plurality of second magnets are alternately arranged in the rotor core along the circumferential direction of the rotor core, two ends of each of the first magnets and each of the second magnets in the length direction are arranged along the axial direction of the rotor core, two side ends of each of the first magnets in the width direction are arranged along the radial direction of the rotor core, and two ends of each of the second magnets in the width direction are arranged along the circumferential direction of the rotor core;
[0022] Among them, the first angle between the line connecting the center of the first magnet and the center of the rotor core and the width direction of the first magnet is α, the second angle between the line connecting the center of the second magnet and the center of the rotor core and the width direction of the second magnet is β, and at least one of α and |β-90°| is set to be greater than 0°.
[0023] The utility model also provides a compressor, the compressor comprising a rotor assembly, the rotor assembly comprising:
[0024] a rotor core; and,
[0025] A plurality of first magnets and a plurality of second magnets are alternately arranged in the rotor core along the circumferential direction of the rotor core, two ends of each of the first magnets and each of the second magnets in the length direction are arranged along the axial direction of the rotor core, two side ends of each of the first magnets in the width direction are arranged along the radial direction of the rotor core, and two ends of each of the second magnets in the width direction are arranged along the circumferential direction of the rotor core;
[0026] Among them, the first angle between the line connecting the center of the first magnet and the center of the rotor core and the width direction of the first magnet is α, the second angle between the line connecting the center of the second magnet and the center of the rotor core and the width direction of the second magnet is β, and at least one of α and |β-90°| is set to be greater than 0°.
[0027] In the technical solution of the present utility model, when the angle α of the first angle between the line connecting the center of the first magnet and the center of the rotor core and the width direction of the first magnet is set to be greater than 0°, the width direction of the first magnet does not extend along the radial direction of the rotor core, but forms a certain angle with the radial direction of the rotor core, then the first magnet can be set wider, thereby improving the utilization rate of the first magnet and increasing the magnetic flux of the rotor assembly; when the angle |β-90°| of the second angle between the line connecting the center of the second magnet and the center of the rotor core and the width direction of the second magnet is set to be greater than 0°, the width direction of the second magnet does not extend along the tangent direction of the rotor core, then the second magnet arranged between two adjacent first magnets can be set wider, thereby improving the utilization rate of the second magnet and increasing the magnetic flux of the rotor assembly, that is, when the magnetic flux remains unchanged, the amount of rare earth permanent magnets can be reduced, so as to provide a motor with reduced rare earth permanent magnet usage under the premise of ensuring the high performance of the permanent magnet motor remains unchanged. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0029] Figure 1 A schematic structural diagram of an embodiment of a rotor assembly provided by the utility model;
[0030] Figure 2 A schematic structural diagram of another embodiment of a rotor assembly provided by the utility model;
[0031] Figure 3 for Figure 1 Schematic diagram of the inclination angles of the first magnet and the second magnet.
[0032] Description of Figure Numbers:
[0033] 100. Rotor assembly; 1. rotor core; 2. first magnet; 3. second magnet.
[0034] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0036] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "α and / or β" as an example, it includes α scheme, or β scheme, or a scheme that satisfies α and β at the same time. 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 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 utility model.
[0038] At present, permanent magnet motors have the advantages of simple structure, reliability, high efficiency and high power density, and are widely used. Among them, thanks to the high magnetic energy product of rare earth permanent magnets, the performance of rare earth permanent magnet motors is excellent. However, the reserves of rare earth resources are very limited, and the home appliance manufacturing industry should actively respond to the national call to reduce its dependence on rare earth permanent magnets. Completely replacing rare earth permanent magnets with non-rare earth permanent magnets will cause serious deterioration in motor performance. Therefore, the mixed use of rare earth permanent magnets and non-rare earth permanent magnets has become an important research direction, which can greatly reduce the amount of rare earth permanent magnets while ensuring the high performance of permanent magnet motors. Among them, how to further expand the reduction of rare earth permanent magnets through motor structure optimization design has become a current research hotspot.
[0039] The utility model provides a rotor assembly, aiming to provide a motor with reduced rare earth permanent magnet usage under the premise of ensuring the high performance of the permanent magnet motor.
[0040] See also Figures 1 to 3 In one embodiment of the utility model, the rotor assembly 100 includes a rotor core 1, a plurality of first magnets 2 and a plurality of second magnets 3, wherein the plurality of first magnets 2 and the plurality of second magnets 3 are alternately arranged in the rotor core 1 along the circumference of the rotor core 1, and the two ends in the length direction of each of the first magnets 2 and each of the second magnets 3 are arranged along the axial direction of the rotor core 1, the two side ends in the width direction of each of the first magnets 2 are arranged along the radial direction of the rotor core 1, and the two ends in the width direction of each of the second magnets 3 are arranged along the circumference of the rotor core 1; wherein a first angle between a line connecting the center of the first magnet 2 and the center of the rotor core 1 and the width direction of the first magnet 2 is α, and a second angle between a line connecting the center of the second magnet 3 and the center of the rotor core 1 and the width direction of the second magnet 3 is β, and at least one of α and |β-90°| is set to be greater than 0°.
[0041] It should be noted that the rotor core 1 has a plurality of mounting grooves for installing the plurality of first magnets 2 and the plurality of second magnets 3, each of the mounting grooves extending along the axial direction of the rotor core 1, and the plurality of mounting grooves include a plurality of first mounting grooves and a plurality of second mounting grooves, the plurality of first mounting grooves being provided for corresponding installation of the plurality of first magnets 2, and the plurality of second mounting grooves being provided for corresponding installation of the plurality of second magnets 3.
[0042] The first magnet 2 is arranged in the length direction of the first magnet 2 in the thickness direction of the rotor core 1, the first magnet 2 is arranged in the width direction of the first magnet 2 in the radial direction along the rotor core 1, and the first magnet 2 is arranged in the thickness direction of the first magnet 2 in the circumferential direction along the rotor core 1.
[0043] The second magnet 3 is arranged in the length direction of the second magnet 3 in the thickness direction of the rotor core 1, the second magnet 3 is arranged in the thickness direction of the second magnet 3 in the radial direction along the rotor core 1, and the second magnet 3 is arranged in the width direction of the second magnet 3 in the circumferential direction along the rotor core 1.
[0044] "The line connecting the center of the first magnet 2 and the center of the rotor core 1" is the line connecting the geometric center of the first magnet 2 and the geometric center of the rotor core 1 on the cross section of the rotor core 1. It can be understood that if there is an angle α greater than 0° between the width direction of the first magnet 2 and the line, it means that the width direction of the first magnet 2 does not coincide with the radial direction of the rotor core 1, and the first magnet 2 is tilted to a certain extent.
[0045] Similarly, "the line connecting the center of the second magnet 3 and the center of the rotor core 1" is the line connecting the geometric center of the second magnet 3 and the geometric center of the rotor core 1 on the cross section of the rotor core 1. It can be understood that if there is an angle |β-90°| between the width direction of the second magnet 3 and the line, if it is equal to 0°, it means that the direction of the width of the second magnet 3 coincides with the tangent direction of the center of the second magnet 3. If |β-90°| is greater than 0°, it means that the width extension direction of the second magnet 3 does not extend along the tangent direction, and the second magnet 3 is tilted to a certain extent.
[0046] It can be understood that the tilting direction of the first magnet 2 and the second magnet 3 can be formed by rotating in a clockwise direction on the original basis, or can be formed by rotating in a counterclockwise direction on the original basis.
[0047] It can be understood that when the rotor assembly 100 is applied to a permanent magnet synchronous motor, the first magnet 2 and the second magnet 3 are configured as permanent magnets to provide a constant magnetic field, which interacts with the rotating magnetic field generated by the stator winding to generate torque.
[0048] In the technical solution of the present invention, when the first angle α between the line connecting the center of the first magnet 2 and the center of the rotor core 1 and the width direction of the first magnet 2 is set to be greater than 0°, the width direction of the first magnet 2 does not extend along the radial direction of the rotor core 1, but forms a certain angle with the radial direction of the rotor core 1, then the first magnet 2 can be set wider, thereby improving the utilization rate of the first magnet 2 and increasing the magnetic flux of the rotor assembly 100; when the line connecting the center of the second magnet 3 and the center of the rotor core 1 is set to be greater than 0°, the width direction of the first magnet 2 does not extend along the radial direction of the rotor core 1, but forms a certain angle with the radial direction of the rotor core 1, then the first magnet 2 can be set wider, thereby improving the utilization rate of the first magnet 2 and increasing the magnetic flux of the rotor assembly 100; When the second angle |β-90°| between the second magnet 3 and the width direction is set to be greater than 0°, the width direction of the second magnet 3 does not extend along the tangent direction of the rotor core 1, then the second magnet 3 arranged between two adjacent first magnets 2 can be arranged wider, thereby improving the utilization rate of the second magnet 3 and increasing the magnetic flux of the rotor assembly 100, that is, when the magnetic flux remains unchanged, the amount of rare earth permanent magnets can be reduced, so as to provide a motor with reduced rare earth permanent magnet usage under the premise of ensuring the high performance of the permanent magnet motor.
[0049] Furthermore, in theory, as long as the first magnet 2 and / or the second magnet 3 are relatively tilted, their width can be set wider, which can improve the utilization rate of the magnets. In order to make the above effect more obvious, in this embodiment, at least one of α and |β-90°| is set to be greater than or equal to 5°. In this way, the rotor assembly 100 can fully reflect the technical effect of increasing magnetic flux.
[0050] In this embodiment, α≤60° and / or |β-90°|≤30°.
[0051] It should be noted that in permanent magnet motors, the arrangement of magnets has a direct impact on the magnetic circuit of the motor, which in turn affects the performance of the motor. The magnetic circuit can be likened to a circuit path in an electric circuit, where the magnetic flux flows in the magnetic circuit like an electric current. Ideally, the magnetic flux should flow from one magnetic pole to another as efficiently as possible, forming a closed path. When the first angle and the second angle are set within the above range, they can help optimize the magnetic flux path and ensure that the magnetic flux can flow between the stator and the rotor in the most efficient way. This improves the utilization of the magnets because the magnetic flux is more concentrated and directed, resulting in stronger electromagnetic torque and higher motor efficiency.
[0052] When the first angle and the second angle are set too large and exceed the above range, the magnetic flux may no longer be completely closed in the predetermined magnetic circuit, but partially leak into the air or other non-magnetic materials. This reduces the effective magnetic flux, reduces the utilization rate of the magnet, and may also cause some parts of the magnetic circuit to be too concentrated, thereby causing local magnetic saturation, which means that the magnetic flux density of those parts reaches the maximum value of the material and cannot be increased, while the magnetic flux of other parts is insufficient, which also reduces the overall magnetic flux efficiency. Therefore, it will affect the magnetic circuit of the rotor assembly 100 and eventually lead to deterioration of the performance of the motor.
[0053] Specifically, in this embodiment, the plurality of first magnets 2 are centrally symmetrically arranged about the center of the rotor core 1 ; and / or the plurality of second magnets 3 are centrally symmetrically arranged about the center of the rotor core 1 .
[0054] In this way, the centrally symmetrical magnet layout helps to form a uniform magnetic field, reduce the magnetic imbalance inside the motor, and avoid vibration and noise when the motor is running. In a permanent magnet synchronous motor, torque is generated by the interaction between the stator current and the magnetic field generated by the permanent magnet. The symmetrical magnet layout ensures that this interaction is balanced no matter what position the rotor rotates to, thereby providing a smooth torque. Therefore, the multiple first magnets 2 are arranged centrally symmetrically about the center of the rotor core 1; and / or the multiple second magnets 3 are arranged centrally symmetrically about the center of the rotor core 1, which not only improves the dynamic response and stability of the motor, but also simplifies the control logic and reduces maintenance and operating costs.
[0055] In this embodiment, the maximum magnetic energy product of the first magnet 2 is set to be greater than the maximum magnetic energy product of the second magnet 3 .
[0056] It should be noted that the maximum magnetic energy product (BHmax) is an indicator of the magnetic energy that a magnet can store at a specific working point, which reflects the performance level of the magnet. The larger the maximum magnetic energy product, the stronger the magnetic performance of the magnet under the same volume.
[0057] It should also be noted that during the operation of the motor, the outer magnet closest to the stator winding is most affected by the armature reaction magnetic field. Placing the first magnet 2 with a higher magnetic energy product on the outside can ensure that the anti-demagnetization performance meets the requirements and improve the reliability of the magnet.
[0058] In the related art, the first magnet 2 with high performance is used on the outside, while the second magnet 3 with lower cost is used on the inside, which can balance the performance and cost and reduce the overall manufacturing cost of the motor.
[0059] In this embodiment, the material of the first magnet 2 is set to be rare earth permanent magnet; and / or the material of the second magnet 3 is set to be ferrite.
[0060] The first magnet is set as a rare earth permanent magnet, and its maximum magnetic energy product is usually greater than 200 kJ / m 3 The material of the second magnet is ferrite, and the maximum magnetic energy product is usually less than 100kJ / m 3 .
[0061] It should be noted that rare earth permanent magnet materials are generally neodymium iron boron (NdFeB) and samarium cobalt (SmCo), and of course other permanent magnet materials containing rare earth elements can also be used. In addition to ferrite, the material of the second magnet 3 can also be manganese aluminum (MnAl), aluminum nickel cobalt (AlNiCo), iron cobalt (FeCo), etc.
[0062] In this embodiment, the magnetization direction of the first magnet 2 is arranged to be consistent with the thickness direction of the first magnet 2 ; and / or the magnetization direction of the second magnet 3 is arranged to be consistent with the thickness direction of the second magnet 3 .
[0063] In this way, the magnetization direction of the magnet is set consistent with its thickness direction, and the first magnet 2 and the second magnet 3 can generate the maximum magnetic flux density between their main planes (i.e., the two larger surfaces) to ensure that the magnet exerts maximum magnetic properties when in use, which helps to optimize the magnetic circuit, ensure that the magnetic flux propagates in the expected direction, reduce magnetic flux leakage, and improve system efficiency to avoid a decrease in magnetic properties and an increase in magnetic flux leakage.
[0064] Furthermore, in this embodiment, the two adjacent first magnets 2 have the same magnetic poles at one end opposite to each other, so as to ensure that the magnetic fluxes of the two adjacent first magnets 2 can be superimposed on each other, rather than being mutually eliminated by adopting different arrangements.
[0065] Furthermore, in this embodiment, the magnetic pole of one end of the second magnet 3 close to the outer side of the rotor core 1 is arranged with the same polarity as the magnetic pole of one end of the two adjacent first magnets 2 that are arranged opposite to each other. The second magnet 3 further superimposes the magnetic flux at the position between the two first magnets 2, so that a magnetic pole region with a larger magnetic flux can be formed in the outer region of the rotor core 1.
[0066] The utility model also proposes a motor, which includes a stator assembly and a rotor assembly 100. The specific structure of the rotor assembly 100 refers to the above embodiment. Since the motor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0067] The utility model also proposes a compressor, which includes a motor. The specific structure of the motor refers to the above embodiment. Since the compressor adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0068] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A rotor assembly, characterized in that: include: Rotor core; as well as, A plurality of first magnets and a plurality of second magnets are alternately arranged in the rotor core along the circumferential direction of the rotor core, two ends of each of the first magnets and each of the second magnets in the length direction are arranged along the axial direction of the rotor core, two side ends of each of the first magnets in the width direction are arranged along the radial direction of the rotor core, and two ends of each of the second magnets in the width direction are arranged along the circumferential direction of the rotor core; Among them, the first angle between the line connecting the center of the first magnet and the center of the rotor core and the width direction of the first magnet is α, the second angle between the line connecting the center of the second magnet and the center of the rotor core and the width direction of the second magnet is β, and at least one of α and |β-90°| is set to be greater than 0°.
2. The rotor assembly according to claim 1, characterized in that At least one of α and |β-90°| is set to be greater than or equal to 5°.
3. The rotor assembly according to claim 2, characterized in that α≤60° and / or |β-90°|≤30°.
4. The rotor assembly according to claim 1, wherein: The plurality of first magnets are centrally symmetrically arranged about the center of the rotor core; and / or, The plurality of second magnets are centrally symmetrically arranged about the center of the rotor core.
5. The rotor assembly according to any one of claims 1 to 4, characterized in that: The maximum magnetic energy product of the first magnet is set to be greater than the maximum magnetic energy product of the second magnet.
6. The rotor assembly according to claim 5, characterized in that The material of the first magnet is set to be rare earth permanent magnet; and / or, The material of the second magnet is set to be ferrite.
7. The rotor assembly according to claim 1, wherein: The magnetization direction of the first magnet is arranged to be consistent with the thickness direction of the first magnet; and / or, The magnetization direction of the second magnet is arranged to be consistent with the thickness direction of the second magnet.
8. The rotor assembly according to claim 7, characterized in that The two first magnets arranged adjacent to each other have magnetic poles at opposite ends having the same polarity.
9. The rotor assembly according to claim 8, characterized in that The magnetic pole polarity of one end of the second magnet close to the outer side of the rotor core is the same as the magnetic pole polarity of one end of two adjacent first magnets that are oppositely arranged.
10. A motor, characterized in that: Comprising a rotor assembly as claimed in any one of claims 1 to 9.
11. A compressor, characterized in that: Comprising the motor as claimed in claim 10.