Motor, compressor and refrigeration apparatus

Abstract

The present application discloses a motor, a compressor and a refrigeration apparatus. The motor comprises a stator and a rotor; the stator comprises a stator iron core and windings; stator slots are formed in the stator iron core; the stator iron core comprises a stator yoke and stator teeth; the stator teeth are connected to the stator yoke; the windings are wound on the stator teeth and are located in the stator slots; the rotor comprises a rotor iron core and permanent magnets; magnet slots are formed in the rotor iron core; the permanent magnets are located in the magnet slots; and the outer diameter and the inner diameter of the stator iron core are D1 and D2, respectively, the thickness of the stator yoke is t, the width of each magnet slot is b, the thickness of the magnet slot is h, the number of poles of the rotor is 2p, there are N permanent magnets, 4.3≤t≤7.0, 0.577≤D2 / D1≤0.6, and 1.3≤b*h*2p*N / 1000≤3.5.

Description

Motors, compressors and refrigeration equipment

[0001] This application claims priority to Chinese patent application No. 202311133527.7 filed on September 4, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] To reduce costs and improve efficiency, compressor motors are currently pushing their power density to the limit. However, excessive motor power density can lead to reliability issues, such as excessive electrical density and temperature rise, and poor overload capacity. Technical issues

[0004] The main purpose of this application is to provide a motor, which aims to improve the overload capacity and efficiency of the motor by reasonably designing the size relationship between the stator and the rotor while ensuring the reliability of the motor and not significantly increasing the cost. Technical Solutions

[0005] To achieve the above objectives, the motor proposed in this application includes:

[0006] a stator, the stator comprising a stator core and windings, the stator core being provided with stator slots, the stator core comprising a stator yoke and stator teeth, the stator teeth being connected to the stator yoke, the windings being wound around the stator teeth and located in the stator slots; and

[0007] The rotor comprises a rotor core and permanent magnets, wherein the rotor core is provided with magnet slots, and the permanent magnets are located in the magnet slots;

[0008] Among them, the outer diameter and inner diameter of the stator core are D1 and D2 respectively, the thickness of the stator yoke is t, the width of the magnet slot is b, the thickness of the magnet slot is h, the number of poles of the rotor is 2p, the number of permanent magnets is N, 4.3≤t≤7.0, 0.577≤D2 / D1≤0.6, 1.3≤b*h*2p*N / 1000≤3.5.

[0009] In one embodiment, there are 12 stator slots.

[0010] In one embodiment, the number of poles of the rotor 2p=8; or the number of poles of the rotor 2p=10.

[0011] In one embodiment, N=2p or N=4p.

[0012] In one embodiment, 70 mm ≤ D1 ≤ 150 mm.

[0013] In one embodiment, 1.2 mm ≤ h ≤ 2.5 mm.

[0014] In one embodiment, the rotor is provided with flow holes for the flow of refrigerant.

[0015] The present application also provides a compressor, comprising the motor as described above.

[0016] The present application also provides a refrigeration device, comprising the compressor as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. 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.

[0018] FIG1 is a cross-sectional view of an embodiment of a motor of the present application;

[0019] FIG2 is a diagram showing various parameters added to FIG1;

[0020] FIG3 is a torque comparison diagram of the motor of the present application;

[0021] FIG4 is a comparison diagram of the efficiency of the motors of the present application.

[0022] Description of Figure Numbers:

[0023] Reference numerals Reference numerals 11 stator core 21 rotor core 111 stator yoke 22 magnet slot 112 stator tooth 23 rivet hole 113 stator slot 24 flow hole 12 winding 25 shaft hole

[0024] 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

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 1 and 2 , the present application provides a motor, comprising:

[0030] a stator, the stator comprising a stator core 11 and windings 12, the stator core 11 being provided with stator slots 113, the stator core 11 comprising a stator yoke 111 and stator teeth 112, the stator yoke 111 being annular, the stator teeth 112 being spaced apart on the inner circumference of the stator yoke 111, the windings 12 being wound around the stator teeth 112 and being located in the stator slots 113; and

[0031] The rotor includes a rotor core 21 and permanent magnets. The rotor core 21 is provided with magnet slots 22 , and the permanent magnets are located in the magnet slots 22 .

[0032] Among them, the outer diameter and inner diameter of the stator core 11 are D1 and D2 respectively, the thickness of the stator yoke 111 is t, the width of the magnet slot 22 is b, the thickness of the magnet slot 22 is h, the number of poles of the rotor is 2p, the number of permanent magnets is N, 4.3≤t≤7.0, 0.577≤D2 / D1≤0.6, 1.3≤b*h*2p*N / 1000≤3.5.

[0033] The motor in 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 113. The stator core 11 includes a stator yoke 111 and stator teeth 112. The stator teeth 112 are connected to the stator yoke 111. The winding 12 is wound around the stator core 11, and the winding 12 is located in the stator slot 113. The rotor includes a rotor core 21 and a permanent magnet. The rotor core 21 is provided with a magnet slot 22. The permanent magnet is located in the magnet slot 22. Furthermore, the outer diameter and inner diameter of the stator core 11 are D1 and D2 respectively, the width of the magnet slot 22 is b, the thickness of the magnet slot 22 is h, the number of poles of the rotor is 2p, the number of permanent magnets is N, 0.577≤D2 / D1≤0.6, 1.3≤b*h*2p*N / 1000≤3.5, by reasonably setting the stator size and rotor size, the overload capacity and efficiency of the motor are improved while ensuring the reliability of the motor and not significantly increasing the cost.

[0034] At the same time, by further limiting the inner diameter and outer diameter of the stator within the range of 0.577 to 0.6, the moment of inertia can be increased, which is beneficial to the stable performance of the low-frequency energy efficiency of the compressor using the motor; at the same time, the motor has optimal demagnetization ability, 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; further, the experimental data of Figures 3 and 4 show that after the stator size and rotor size are reasonably set in this application, when the current is greater than 6A, the torque of this embodiment is significantly greater than the reference value, and at different speeds of 30rps / 60rps / 90rps, the motor efficiency of this embodiment is significantly higher than the reference value.

[0035] The stator core 11 includes a plurality of stator punchings stacked in sequence, and the stator slots 113 are provided on the stator punchings. The rotor core 21 includes a plurality of rotor punchings stacked in sequence, and the magnet slots 22 are provided on the rotor punchings. By setting the stator punchings and the rotor punchings to be multiple, when processing the stator core 11 and the rotor core 21, only a plurality of stator punchings or rotor punchings need to be processed, and then the plurality of stator punchings and rotor punching parts are assembled into the stator core 11 and the rotor core 21. Compared with processing a complete stator core 11 and rotor core 21, the difficulty of processing the stator punchings and rotor punching parts is reduced, which facilitates the automated production of the stator core 11 and the rotor core 21 through an automated production line, thereby reducing production costs.

[0036] 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 stator and rotor processing technologies. This facilitates the selection of appropriate punchings to form the rotor core 21 and stator core 11 based on the performance requirements of the motor, thereby ensuring good electrode performance and increasing the 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.

[0037] Furthermore, the punching sheets are made of soft magnetic material. Soft magnetic materials can achieve a large magnetization intensity with a small external magnetic field. Soft magnetic materials have low coercivity and high magnetic permeability, which are beneficial for reducing the loss of the stator core 11 and / or the rotor core 21, that is, reducing 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.

[0038] 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.

[0039] 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 offset between the rotor core 21 punchings 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 a plurality of rivet holes 23. The cooperation between the rivets and the rivet holes 23 ensures the fixing strength between the silicon steel sheets, thereby preventing the problem of misalignment between the silicon steel sheets during subsequent processing.

[0040] 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 23 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.

[0041] In this embodiment, the stator slots 113 are provided with 12. Currently, the number of stator slots 113 in variable-frequency motors for household air-conditioning compressors is 6 or 9. First, the number of stator slots 113 determines the distribution of the stator windings 12, which in turn affects the motor's magnetic field distribution. A larger number of stator slots 113 can provide a more uniform magnetic field distribution, reducing magnetic field inhomogeneity, thereby improving the motor's efficiency and performance. Second, within a certain range, increasing the number of stator slots 113 can reduce magnetic field saturation. When current passes through the stator windings 12, the magnetic field can cause the iron core to saturate, thereby reducing the motor's efficiency and performance. Appropriately increasing the number of stator slots 113 can reduce magnetic field saturation and improve the motor's output power and efficiency. At the same time, a smaller number of stator slots 113 may lead to the generation of harmonic magnetic fields, which can cause vibration and noise in the motor. Therefore, increasing the number of stator slots 113 can reduce the generation of harmonic magnetic fields and improve the motor's operating smoothness and quietness. Therefore, in this embodiment, the number of stator slots 113 is set to 12, thereby increasing various performances of the motor, reducing noise generation, and improving the cost-effectiveness of the motor.

[0042] In this embodiment, the number of rotor poles 2p = 8; or the number of rotor poles 2p = 10. The number of rotor poles commonly used in households is generally 4 or 6. The speed of a motor is closely related to the number of rotor poles. Generally, the more poles there are, the higher the speed and the higher the efficiency of the motor. The more poles there are, the smaller the rotational diameter, the higher the frequency of the electromotive force and magnetic field of each phase, the greater the electromotive force per cycle, and the higher the no-load speed of the motor. Under load, the speed will decrease under load due to the allowable heat loss limiting the no-load speed. This is limited by the allowable load conditions, and the power consumption will also decrease accordingly. Therefore, in this embodiment, by setting the number of poles to 8 or 10, the efficiency of the motor is improved and the power consumption of the motor is reduced.

[0043] In this embodiment, N=2p or N=4p. It should be noted that the number of rotor poles refers to the number of magnetic poles on the motor rotor. The number of magnetic poles of a motor determines its performance and characteristics. The more rotor poles, the greater the motor torque, but the lower the speed. Conversely, the fewer rotor poles, the faster the motor speed, but the lower the torque. Therefore, by setting the number of rotor poles to 2p and 4p, both the torque and speed requirements of the compressor can be met, thereby improving the cost-effectiveness of the motor.

[0044] In this embodiment, 70 mm ≤ D1 ≤ 150 mm. The outer diameter of the stator core 11 is D1, and 70 mm ≤ D1 ≤ 150 mm. By limiting the outer diameter range of the stator laminations, the motor's anti-demagnetization capability can be increased, further reducing the use of rare earth elements, thereby reducing the motor's manufacturing costs and improving the motor's cost-effectiveness. A stator outer diameter within the range of 70 to 150 mm can meet the requirements of motors used in compressors.

[0045] In this embodiment, 1.2 mm ≤ h ≤ 2.5 mm. The magnet slot 22 is adapted to the permanent magnet in the thickness direction. Therefore, when h ≤ 1.2 mm, that is, when the thickness of the permanent magnet is small, the magnetic flux density is small, which in turn results in a small output power of the motor, thereby reducing the efficiency of the motor. When x ≥ 2.5 mm, that is, when the thickness of the permanent magnet is large, magnetic circuit saturation occurs, resulting in increased magnetic circuit loss, thereby reducing the efficiency of the motor. Therefore, by controlling the thickness of the magnet slot 22 and the permanent magnet to be between 1.2 mm and 2.5 mm, the output power of the motor can meet the requirements of the compressor, while not making the thickness of the permanent magnet too large, thereby reducing magnetic circuit loss and improving the efficiency of the motor.

[0046] 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.

[0047] 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 23. The cooperation between the rivets and the rivet holes 23 ensures sufficient fixing strength between the silicon steel sheets, thereby preventing inter-layer misalignment of the silicon steel sheets during subsequent processing.

[0048] 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 23 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.

[0049] In this embodiment, an axial hole 25 and a flow hole 24 are further provided on the rotor core 21. The axial hole 25 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, thereby causing the permanent magnet to lose its magnetism or reduce its magnetism. Therefore, in this embodiment, a flow hole 24 is provided on the rotor core 21, and a refrigerant flows through the flow hole 24. The refrigerant can reduce the temperature of the rotor core 21, thereby maintaining the permanent magnet within an optimal range, thereby improving the performance of the motor.

[0050] In one embodiment, the mass percentage of heavy rare earth elements in the permanent magnet is in the range of 0 to 1.5%; or the mass percentage of dysprosium and / or terbium in the permanent magnet is in the range of 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 is positively correlated with the intrinsic coercivity hcj of the permanent magnet, on the one hand, by limiting the mass percentage of dysprosium and / or terbium in the permanent magnet to 0 to 1.5%, it is beneficial to reduce the use of dysprosium and / or terbium while ensuring good anti-demagnetization capability of the motor, thereby reducing the manufacturing cost of the motor and improving the cost-effectiveness of the motor. On the other hand, by limiting the mass percentage of heavy rare earth elements in the permanent magnet to 0 to 1.5%, it is beneficial to reduce the use of heavy rare earth elements while ensuring good anti-demagnetization capability of the motor, thereby reducing the manufacturing cost of the motor and improving the cost-effectiveness of the motor.

[0051] In another embodiment, the mass percentage of dysprosium and / or terbium in the permanent magnet is 0. On the one hand, the mass percentage of dysprosium in the permanent magnet is 0, that is, the permanent magnet does not contain the heavy rare earth element dysprosium, which reduces the permanent magnet's consumption of the heavy rare earth element dysprosium, which is beneficial to energy conservation; on the other hand, the mass percentage of terbium in the permanent magnet is 0, that is, the permanent magnet does not contain the heavy rare earth element terbium, which reduces the permanent magnet's consumption of the heavy rare earth element terbium, which is beneficial to energy conservation; on the other hand, the sum of the mass percentages of dysprosium and terbium in the permanent magnet is 0, that is, the permanent magnet does not contain the heavy rare earth element dysprosium and terbium, which reduces the permanent magnet's consumption of the heavy rare earth elements dysprosium and terbium, which is beneficial to the sustainable development of resources, energy conservation, and reduction of the manufacturing cost of the motor, and is suitable for promotion and application.

[0052] It is understood that the mass percentage of dysprosium and / or terbium in the permanent magnet may also be other values, for example, the mass percentage of dysprosium and / or terbium in the permanent magnet is 0.005%, 0.01%, 0.025%, etc. Furthermore, the permanent magnet is a neodymium iron boron permanent magnet, which has excellent magnetic properties and can meet the use requirements of the motor.

[0053] Specifically, the remanence Br of the permanent magnet is in the range of 1.28T to 1.5T. Remanence refers to the surface field retained after the permanent magnet is magnetized to technical saturation and the external magnetic field is removed. Br is the residual magnetic induction intensity. By properly setting the remanence, under the same magnetic load, the larger the remanence Br value, the less rare earth elements are used in the permanent magnet, thereby reducing the manufacturing cost of the motor. At the same time, by properly setting the remanence, it is beneficial to reduce iron loss and thus improve the efficiency of the motor. Specifically, the remanence of the permanent magnet is 1.28T, or 1.32T, or 1.5T, where T is the unit Tesla.

[0054] 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.

[0055] 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.

[0056] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A motor, comprising: A stator, the stator comprising a stator core and a winding, the stator core being provided with stator slots, the stator core comprising a stator yoke and stator teeth, the stator teeth being connected to the stator yoke, the winding being wound around the stator teeth and being located in the stator slots; and A rotor, the rotor comprising a rotor core and a permanent magnet, the rotor core being provided with a magnet slot, the permanent magnet being located in the magnet slot; Among them, the outer diameter and inner diameter of the stator core are D1 and D2 respectively, the thickness of the stator yoke is t, the width of the magnet slot is b, the thickness of the magnet slot is h, the number of poles of the rotor is 2p, the number of permanent magnets is N, 4.3≤t≤7.0, 0.577≤D2 / D1≤0.6, 1.3≤b*h*2p*N / 1000≤3.

5.

2. The motor according to claim 1, wherein: The stator is provided with 12 slots.

3. The motor according to claim 1 or 2, wherein: The number of poles of the rotor is 2p=8; or the number of poles of the rotor is 2p=10.

4. The electric machine according to any one of claims 1 to 3, wherein: N=2p or N=4p.

5. The electric machine according to any one of claims 1 to 4, wherein: 70mm≤D1≤150mm.

6. The electric machine according to any one of claims 1 to 5, wherein: 1.2mm≤h≤2.5mm.

7. The electric machine according to any one of claims 1 to 6, wherein: The rotor is provided with flow holes for the flow of refrigerant.

8. A compressor comprising the motor according to any one of claims 1 to 7.

9. A refrigeration device comprising the compressor according to claim 8.

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