Motor, compressor, and refrigeration device

Abstract

A motor, a compressor, and a refrigeration device. The motor comprises a stator and a rotor. The stator comprises a stator core (11) and a winding (12). The stator core (11) is provided with stator slots (111). The winding (12) is wound on the stator core (11) and is located in the stator slots (111). The rotor comprises a rotor core (21) and a plurality of permanent magnets (22). The rotor core (21) is provided with a plurality of magnet slots per pole (23). The permanent magnets (22) are located in the magnet slots per pole (23). The quantity of the stator slots (111) is 15, the quantity of poles of the rotor is 10, the intrinsic coercive force of the permanent magnets (22) is hcj, the included angle between the magnet slots per pole (23) is α, the thickness of the permanent magnet (22) in the magnetization direction is h, hcj≤1,800 kA / m, 11*α / hcj≤h≤50*α / hcj, and α / hcj is an anti-demagnetization factor.

Description

Motors, compressors and refrigeration equipment

[0001] This application claims priority to Chinese patent application No. 202311153341.8 filed on September 7, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of motor technology, and in particular to a motor, a compressor, and a refrigeration device. Background Art

[0003] China is currently placing higher demands on the energy efficiency of compressors in the household air conditioning sector. The motor, the compressor's power element, has a direct impact on its efficiency. Currently, most compressor motors use variable-frequency motors, which utilize permanent magnets. Permanent magnets contain many rare elements, such as dysprosium and terbium. Heavy rare earth elements are strategic national resources, and their price has been increasing annually with the development of new energy and variable-frequency drives in the home appliance industry.

[0004] To reduce reliance on rare earth elements and lower motor costs, permanent magnets with a relatively low rare earth content can be used. This reduction in rare earth content reduces the permanent magnet's intrinsic coercivity, which directly affects the motor's anti-demagnetization performance. Therefore, it is necessary to design a motor structure that can accommodate a low rare earth content.

[0005] The number of stator slots of the variable frequency motor currently used in household air-conditioning compressors is 6, 9, or 12, and the number of rotor poles is 4, 6, or 8. The number of slots in the motor directly affects the demagnetization ability of the motor. When the number of slots in the motor increases, the demagnetization ability of the motor increases. Technical issues

[0006] The main purpose of this application is to provide a motor that aims to reduce the use of heavy rare earth elements, reduce the cost of magnets, and improve the cost performance of the motor by adjusting the relationship between the anti-demagnetization factor and the thickness of the magnet, while ensuring that the demagnetization meets the requirements. Technical Solutions

[0007] To achieve the above-mentioned purpose, the motor proposed in this application includes:

[0008] A stator, the stator comprising a stator core and windings, the stator core being provided with stator slots, the windings being wound around the stator core and located in the stator slots; and

[0009] A rotor, comprising a rotor core and a plurality of permanent magnets, wherein the rotor core is provided with a plurality of magnet slots per pole, and the permanent magnets are located in the magnet slots per pole;

[0010] The number of stator slots is , the number of rotor poles is , the intrinsic coercive force of the permanent magnet is hcj, the angle between the magnet slots of each pole is α, the thickness of the permanent magnet along the magnetization direction is h, hcj≤1800kA / m, 11*α / hcj≤h≤50*α / hcj, and α / hcj is the anti-demagnetization factor.

[0011] In one embodiment, the magnet slots of each pole are arranged in a V-shape, with 90°≤α<180°.

[0012] In one embodiment, 100°≤α<130°.

[0013] In one embodiment, α=180°.

[0014] In one embodiment, the mass percentage of heavy rare earth elements in the permanent magnet is in the range of 0 to 1.5%; the mass percentage of dysprosium and / or terbium in the permanent magnet is in the range of 0 to 1.5%.

[0015] In one embodiment, the remanence Br of the permanent magnet is in the range of 1.28T to 1.5T.

[0016] In one embodiment, the outer diameter of the stator is D, and 85 mm ≤ D ≤ 200 mm.

[0017] In one embodiment, the inner diameter of the stator is Di, the outer diameter of the stator is D, and 0.45≤Di / D≤0.65.

[0018] The present application also provides a compressor, which includes the motor as described above.

[0019] The present application also provides a refrigeration device, which includes the compressor as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] FIG1 is a schematic structural diagram of a motor according to an embodiment of the present application in which the magnet slots of each pole are arranged in a V-shape;

[0022] FIG2 is a schematic structural diagram of a motor according to an embodiment of the present application in which the magnet slots of each pole are arranged in a straight line;

[0023] FIG3 is a diagram showing various parameters added to FIG1;

[0024] FIG4 is a comparison diagram of evaluation samples and reference values ​​of the motor of the present application at different currents;

[0025] FIG5 is a comparison diagram of the evaluation samples and the reference values ​​of the motor of the present application at different speeds.

[0026] Description of Figure Numbers:

[0027] Reference numerals Reference numerals 11 stator core 22 permanent magnet 111 stator slot 23 magnet slot per pole 12 winding 24 rivet hole 21 rotor core

[0028] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, "and / or" in the full text includes three solutions. Taking A and / or B as an example, it includes technical solution A, technical solution B, and technical solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. 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 this application.

[0033] 1 to 3 , the present application provides a motor, comprising:

[0034] A stator, the stator comprising a stator core 11 and a winding 12, the stator core 11 being provided with stator slots 111, the winding 12 being wound around the stator core 11 and located in the stator slots 111; and

[0035] The rotor includes a rotor core 21 and a plurality of permanent magnets 22. The rotor core 21 is provided with a plurality of magnet slots 23 per pole. The permanent magnets 22 are located in the magnet slots 23 per pole.

[0036] The number of slots of the stator slots 111 is 15, the number of poles of the rotor is 10, the intrinsic coercive force of the permanent magnet 22 is hcj, the angle of the magnet slot 23 per pole is α, the thickness of the permanent magnet 22 along the magnetization direction is h, hcj≤1800 kA / m, 11*α / hcj≤h≤50*α / hcj, and α / hcj is the anti-demagnetization factor.

[0037] The motor of the technical solution of the present application includes a stator and a rotor, the stator includes a stator core 11 and a winding 12, the stator core 11 is provided with a stator slot 111, the winding 12 is wound on the stator core 11, and the winding 12 is located in the stator slot 111, the rotor includes a rotor core 21 and a plurality of permanent magnets 22, the rotor core 21 is provided with a plurality of magnet slots 23 per pole, the permanent magnet 22 is located in the magnet slot 23 per pole, wherein the number of slots of the stator slot 111 is 15, the number of poles of the rotor is 10, the intrinsic coercive force of the permanent magnet 22 is defined as hcj (unit kA / m), the angle of the magnet slot per pole is α (unit °), and the permanent magnet 22 is magnetized along the The thickness in the direction is h (unit: mm), hcj≤1800kA / m, and by further defining the relationship between hcj, α and h, 11*α / hcj≤h≤50*α / hcj, where α / hcj is the anti-demagnetization factor, the technical solution of the present application provides a 15-slot, 10-pole variable-frequency motor for a compressor. The slot-pole structure of the motor has a stronger anti-demagnetization ability than the current existing household air-conditioning motor structure. At the same time, by adjusting the relationship between the anti-demagnetization factor and the thickness of the magnet, the use of heavy rare earth elements is reduced, the cost of magnets is reduced, and the cost performance of the motor is improved while ensuring that the demagnetization meets the requirements.

[0038] The number of slots in the stator slots 111 of the current variable frequency motor for household air-conditioning compressors is 6, 9, and 12, and the number of rotor poles is 4, 6, and 8. The number of slots in the stator slots 111 of the motor directly affects the demagnetization ability of the motor, that is, when the number of stator slots of the motor increases, the demagnetization ability of the motor is enhanced, and thus the anti-demagnetization ability of the motor is enhanced; while in this application, the number of slots in the stator slots 111 is 15, and the number of rotor poles is 10, thereby further increasing the demagnetization ability and anti-demagnetization ability of the motor compared to the current household air conditioners.

[0039] It should be noted that the saturated rotor is first placed at room temperature, and the rotor magnetic flux φ0 is measured. The rotor, after the initial magnetic flux test, is then placed in a constant temperature oven for at least four hours, with the oven temperature set to the specified 130°C. The test DC motor is then connected to a DC power supply, and the demagnetization current is set to a pre-set value (35A, 40A, 45A, etc.). Once ready, the rotor is removed from the constant temperature oven, the demagnetization test fixture is installed, and the rotor is rotated once under the DC demagnetization current. After completion, the rotor is left at room temperature for at least four hours, and the rotor temperature and post-demagnetization magnetic flux φ1 are measured. Finally, the demagnetization rate is calculated using the following formula: (φi must be calculated at the same temperature as φ0): Demagnetization rate = (φi - φ0) / φ0 × 100%.

[0040] Furthermore, the demagnetization rate of the rotor is affected by current and temperature. By comparing the motor of the present application and the reference value under different current conditions in Figure 4, it can be seen that under different current conditions, the demagnetization rate of the motor of the present application is very close to the reference value. This shows that the motor of the present application can meet the needs of the compressor.

[0041] Furthermore, referring to FIG. 5 , it can be seen that the motor efficiency in the present application at different motor speeds is very close to the reference value, which shows that the motor in the present application can meet the requirements of the compressor.

[0042] 1 and 3 , in one embodiment, the magnet slot 23 of each pole is V-shaped, 90°≤α<180°; when α is less than 90° or α>180°, the permanent magnet 22 is not easily magnetized, and the utilization efficiency of the permanent magnet 22 is low. Therefore, when 90°≤α<180°, the utilization efficiency of the permanent magnet 22 can be improved.

[0043] Furthermore, 100°≤α<130°, by further limiting the numerical range of α, the utilization efficiency of the permanent magnet 22 is further improved.

[0044] 2 , in another embodiment, α=180°, that is, the magnet slots 23 of each pole are arranged in a straight line. In this case, the permanent magnets 22 are also easy to magnetize, and the utilization efficiency of the permanent magnets 22 is high, thereby improving the performance of the motor.

[0045] In other embodiments, the structure of the magnet slot 23 of each pole can also be set to a variety of different styles such as U-shaped slot, W-shaped slot or I-shaped slot. By setting the magnet slot 23 of each pole to a variety of different styles such as V-shaped slot, U-shaped slot, W-shaped slot, straight slot or I-shaped slot, it is possible to install permanent magnets 22 of different structures therein, making the motor manufacturing process more flexible and with more choices, which can meet a variety of different application scenarios and expand the applicability of the product.

[0046] In one embodiment, the mass percentage of heavy rare earth elements in the permanent magnet 22 ranges from 0 to 1.5%; or the mass percentage of dysprosium and / or terbium in the permanent magnet 22 ranges from 0 to 1.5%. Since dysprosium and terbium are heavy rare earth elements, which are national strategic resources, and the mass percentage of heavy rare earth elements in the permanent magnet 22 is positively correlated with the intrinsic coercivity hcj of the permanent magnet 22, limiting the mass percentage of dysprosium and / or terbium in the permanent magnet 22 to 0 to 1.5% helps reduce the use of dysprosium and / or terbium while ensuring good demagnetization resistance of the motor, thereby reducing the manufacturing cost of the motor and improving the cost-effectiveness of the motor. Furthermore, limiting the mass percentage of heavy rare earth elements in the permanent magnet 22 to 0 to 1.5% helps reduce the use of heavy rare earth elements while ensuring good demagnetization resistance of the motor, thereby reducing the manufacturing cost of the motor and improving the cost-effectiveness of the motor.

[0047] In another embodiment, the mass percentage of dysprosium and / or terbium in the permanent magnet 22 is 0. On the one hand, the mass percentage of dysprosium in the permanent magnet 22 is 0, that is, the permanent magnet 22 does not contain the heavy rare earth element dysprosium, which reduces the consumption of the heavy rare earth element dysprosium by the permanent magnet 22, which is beneficial to energy saving; on the other hand, the mass percentage of terbium in the permanent magnet 22 is 0, that is, the permanent magnet 22 does not contain the heavy rare earth element terbium, which reduces the consumption of the heavy rare earth element terbium by the permanent magnet 22, which is beneficial to energy saving; on the other hand, the sum of the mass percentages of dysprosium and terbium in the permanent magnet 22 is 0, that is, the permanent magnet 22 does not contain the heavy rare earth element dysprosium and terbium, which reduces the consumption of the heavy rare earth elements dysprosium and terbium by the permanent magnet 22, which is beneficial to the sustainable development of resources, energy saving, and reducing the manufacturing cost of the motor, and is suitable for promotion and application.

[0048] It is understood that the mass percentage of dysprosium and / or terbium in the permanent magnet 22 may also be other values, for example, the mass percentage of dysprosium and / or terbium in the permanent magnet 22 is 0.005%, 0.01%, 0.025%, etc. Furthermore, the permanent magnet 22 is a neodymium iron boron permanent magnet, which has excellent magnetic properties and can meet the use requirements of the motor.

[0049] In one embodiment, the remanence Br of the permanent magnet 22 ranges from 1.28T to 1.5T. Remanence refers to the surface field remaining after the permanent magnet 22 is magnetized to technical saturation and the external magnetic field is removed, and Br is the residual magnetic induction intensity. By properly setting the remanence, under the same magnetic load, a larger remanence Br value indicates a lower amount of rare earth elements in the permanent magnet 22, thereby reducing the manufacturing cost of the motor. Furthermore, properly setting the remanence helps reduce iron loss and improve the efficiency of the motor. Specifically, the remanence of the permanent magnet 22 is 1.28T, 1.32T, or 1.5T, where T is the unit Tesla.

[0050] In this embodiment, the stator outer diameter is D, and 85 mm ≤ D ≤ 200 mm. By limiting the stator outer diameter range, the motor's anti-demagnetization capability can be increased, further reducing the use of rare earth elements, thereby lowering the motor's manufacturing cost and improving its cost-effectiveness. Furthermore, a stator outer diameter within the range of 85 to 200 mm meets the requirements of motors used in compressors.

[0051] In one embodiment, the inner diameter of the stator is Di, the outer diameter of the stator is D, and 0.45≤Di / D≤0.65; by further limiting the inner diameter and outer diameter of the stator to a range of 0.45 to 0.65, the moment of inertia can be increased, thereby facilitating the stable low-frequency energy efficiency of a compressor using the motor; at the same time, the motor has optimal demagnetization capability, thereby obtaining higher system energy efficiency; at the same time, the use of rare earth elements is further reduced, thereby reducing the production cost of the motor, thereby improving the cost performance of the motor.

[0052] In one embodiment, the stator core 11 is formed by stacking a plurality of stator punchings, and the rotor core 21 is formed by stacking rotor punchings. In one embodiment, the rotor core 21 and the stator core 11 can be made of different materials or shapes, thereby meeting the requirements of different processing technologies for the stator and rotor, and facilitating the selection of appropriate punchings to form the rotor core 21 and the stator core 11 according to the performance requirements of the motor, thereby ensuring good performance of the electrodes and also increasing the wide range of applicability of the motor. In another embodiment, the stator punchings stacked to form the stator core 11 and the rotor punchings stacked to form the rotor core 21 are the same, thereby facilitating mass production of the punchings and reducing manufacturing costs.

[0053] In one embodiment, the punching sheets are made of soft magnetic material. Soft magnetic materials can achieve a high magnetization intensity with a small external magnetic field. Soft magnetic materials have low coercivity and high magnetic permeability, which helps reduce the loss of the stator core 11 and / or the rotor core 21, that is, reduces the iron loss of the motor, thereby improving the performance of the motor. Specifically, the punching sheets are silicon steel sheets, but it is understood that the punching sheets can also be made of other materials.

[0054] There are many factors that affect eddy current losses, including the cross-sectional area and thickness of the magnetic material, the frequency of the induced electromotive force, and the magnetic flux density. By configuring the rotor core 21 and the stator core 11 to be respectively composed of multiple layers of mutually insulated rotor punchings and stator punchings, the eddy currents can be suppressed within each layer of rotor punchings or stator punchings, thereby reducing the eddy current losses generated thereby. In other words, by avoiding interlayer eddy current conduction, the overall eddy current losses of the rotor core 21 and the stator core 11 can be significantly reduced. Specifically, the stator core 11 and the rotor core 21 are usually configured as silicon steel sheets, which can have their own paint film to form an insulating surface layer, or can have the motor manufacturer apply insulating paint on the paint-free punching film to form an insulating surface layer, or can have the motor manufacturer oxidize the punching film to form an insulating surface layer.

[0055] In the related art, to ensure that the rotor core 21 does not become loose or misaligned between layers, or to ensure that the rotor core 21 does not deform due to inter-layer offset during the winding process of the coil winding 12, the motor core is required to have sufficient stacking riveting strength. To ensure this sufficient stacking riveting strength, in this embodiment, the rotor core 21 is provided with multiple rivet holes 24. The cooperation between the rivets and the rivet holes 24 ensures sufficient fixing strength between the silicon steel sheets, thereby preventing inter-layer misalignment of the silicon steel sheets during subsequent processing.

[0056] It should be noted that in order to reduce or even avoid the inter-layer eddy current conduction problem caused by this stacked riveting structure, the rotor punchings can be bonded with glue instead of the stacked riveting method, which can prevent the insulating surface layer of the silicon steel sheet at the rivet hole 24 from being damaged, thereby avoiding the problem of eddy current inter-layer conduction. However, due to the high price of glue and low production efficiency of the production line, it has not been used in the motor of the air-conditioning compressor.

[0057] In this embodiment, an axial hole and a flow hole are further provided on the rotor core 21. The axial hole is used to install a transmission shaft, thereby driving the transmission object to rotate; after the motor is used for a long time, its temperature is likely to rise, which may easily lead to demagnetization of the permanent magnet 22, thereby causing the permanent magnet 22 to lose its magnetism or reduce its magnetism. Therefore, in this embodiment, a flow hole is provided on the rotor core 21, and a refrigerant flows through the flow hole. The refrigerant can reduce the temperature of the rotor core 21, thereby maintaining the permanent magnet 22 within the optimal range, thereby improving the performance of the motor.

[0058] The present application also proposes a compressor, which includes a motor. The specific structure of the motor refers to the above-mentioned embodiment. Since the compressor of the present application adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0059] The present application also proposes a refrigeration device, which includes the above-mentioned compressor, wherein the refrigeration device can be but is not limited to refrigerators, freezers, air conditioners and other devices with refrigeration functions. The specific structure of the compressor refers to the above-mentioned embodiments. Since the refrigeration device of the present application adopts all the technical solutions of all the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0060] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A motor, wherein: The motor comprises: A stator, the stator comprising a stator core and a winding, the stator core being provided with stator slots, the winding being wound on the stator core and located in the stator slots; and A rotor, the rotor comprising a rotor core and a plurality of permanent magnets, the rotor core being provided with a plurality of magnet slots per pole, the permanent magnets being located in the magnet slots per pole; The number of stator slots is 15, the number of rotor poles is 10, the intrinsic coercive force of the permanent magnet is hcj, the angle of each pole magnet slot is α, the thickness of the permanent magnet along the magnetization direction is h, hcj≤1800kA / m, 11*α / hcj≤h≤50*α / hcj, α / hcj is the anti-demagnetization factor.

2. The motor according to claim 1, wherein: The magnet slots of each pole are arranged in a V shape, 90°≤α<180°.

3. The motor according to claim 2, wherein: 100°≤α<130°。 4. The electric machine according to any one of claims 1 to 3, wherein: α＝180°。 5. The electric machine according to any one of claims 1 to 4, wherein: The mass percentage of dysprosium and / or terbium in the permanent magnet is in the range of 0 to 1.5%; the mass percentage of heavy rare earth elements in the permanent magnet is in the range of 0 to 1.5%.

6. The electric machine according to any one of claims 1 to 5, wherein: The remanence Br of the permanent magnet ranges from 1.28T to 1.5T.

7. The electric machine according to any one of claims 1 to 6, wherein: The outer diameter of the stator is D, 85mm≤D≤200mm.

8. The electric machine according to any one of claims 1 to 7, wherein: The inner diameter of the stator is Di, the outer diameter of the stator is D, and 0.45≤Di / D≤0.

65.

9. A compressor, wherein: The compressor comprises a motor as claimed in any one of claims 1 to 8.

10. A refrigeration device, wherein: The refrigeration device comprises a compressor as claimed in claim 9.

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