Motors, compressors, and cooling equipment

Abstract

A motor, compressor, and cooling device are disclosed, the motor comprising a stator and a rotor, the stator comprising a stator core (11) on which a stator rod (111) is provided and a winding (12) wound around the stator core (11) and located within the stator rod (111), the rotor comprising a rotor core (21) on which a plurality of pole magnet slots (23) are provided and a plurality of permanent magnets (22) located within the pole magnet slots (23), the number of slots in the stator rod (111) being 15, the number of poles of the rotor being 10, the intrinsic coercivity of the permanent magnets (22) being hcj, the angle between the pole magnet slots (23) being α, and the thickness of the permanent magnets (22) along the magnetization direction being h, then hcj ≤ 1800 kA / m, 11 × α / hcj ≤ h ≤ 50 × α / hcj, where α / hcj is the demagnetizing coefficient.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with the application number 202311153341.8 filed on September 7, 2023, and all of its content is incorporated herein by reference.

[0002] This application relates to the field of motor technology, particularly to motors, compressors, and cooling devices.

Background Art

[0003] China is currently increasing the requirements for the energy efficiency of compressors in the household air conditioner field. The motor is the power element of the compressor, and the efficiency of the motor directly affects the energy efficiency of the compressor. Currently, most compressor motors adopt variable frequency motors using permanent magnets. Permanent magnets contain many rare elements such as dysprosium and terbium. Heavy rare earth elements are national strategic resources, and with the development of the variable frequency of the new energy industry and the household appliance industry, the price of heavy rare earth elements has been increasing year by year.

[0004] In order to reduce the dependence on rare earth elements and reduce the cost of the motor, permanent magnets with relatively low rare earth element content can be used. When the rare earth elements are reduced, the intrinsic coercive force of the permanent magnet decreases, and the intrinsic coercive force directly affects the demagnetization resistance performance of the motor. Therefore, it is necessary to design a motor structure with a low rare earth element content.

[0005] Currently, the number of stator slots of the variable frequency motors used in household air conditioner compressors is 6, 9, or 12, and the number of rotor poles is 4, 6, or 8. The number of slots of the motor directly affects the demagnetization ability of the motor. When the number of slots of the motor increases, the demagnetization ability of the motor improves.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The main objective of this application is to provide motors, compressors, and cooling equipment that improve the cost-effectiveness of motors by reducing the use of heavy rare earth elements and the cost of magnets, while ensuring that demagnetization satisfies the requirements, by adjusting the relationship between the demagnetization coefficient and the thickness of the magnet. [Means for solving the problem]

[0007] To achieve the above objective, this application proposes a motor comprising a stator including a stator core on which status rods are provided and a winding wound around the stator core and located on the status rods, a rotor including a rotor core on which a plurality of pole magnet slots are provided and a plurality of permanent magnets located within the pole magnet slots, wherein if the number of slots in the status rods is 15, the number of poles in the rotor is 10, the intrinsic coercivity of the permanent magnets is hcj, the angle between the pole magnet slots is α, and the thickness of the permanent magnets along the magnetization direction is h, then hcj ≤ 1800 kA / m, and 11 × α / hcj ≤ h ≤ 50 × α / hcj, where α / hcj is the demagnetizing coefficient.

[0008] In one embodiment, the pole magnet slots are arranged in a V-shape, and 90° ≤ α < 180°.

[0009] In one embodiment, 100° ≤ α < 130°.

[0010] In one embodiment, α = 180°.

[0011] In one embodiment, the mass percentage range of the heavy rare earth elements in the permanent magnet is 0 to 1.5%, and the mass percentage range of dysprosium and / or terbium in the permanent magnet is 0 to 1.5%.

[0012] In one embodiment, the range of the residual magnetic flux density Br of the permanent magnet is 1.28T to 1.5T.

[0013] In one embodiment, if the outer diameter of the stator is D, then 85 mm ≤ D ≤ 200 mm.

[0014] In one embodiment, if the inner diameter of the stator is Di and the outer diameter of the stator is D, then 0.45 ≤ Di / D ≤ 0.65.

[0015] This application further provides a compressor including the above-mentioned motor.

[0016] This application further provides a cooling device including the above-mentioned compressor. [Brief explanation of the drawing]

[0017] To more clearly illustrate the embodiments of this application or the technical solutions of the prior art, the following drawings, which may be used in the description of the embodiments or the prior art, are briefly introduced below. Clearly, the drawings described below represent only a few embodiments of this application, and further drawings can be obtained based on the structures shown in these drawings, assuming that a person skilled in the art does not require any creative work.

[0018] [Figure 1] This is a schematic diagram showing the structure when the pole magnet slots are arranged in a V-shape in one embodiment of the motor according to this application. [Figure 2] This is a schematic diagram showing the structure when each pole magnet slot is installed in a single line in one embodiment of the motor according to this application. [Figure 3] This is a diagram with each parameter added, as shown in Figure 1. [Figure 4] This is a comparison diagram of evaluation specifications and reference values ​​for the motor described in this application at different currents. [Figure 5] This is a comparison diagram of evaluation specifications and reference values ​​for the motor described in this application at different rotational speeds. [Modes for carrying out the invention]

[0019] The achievement of the objectives of this application, its functional features, and advantages will be further described with reference to the drawings, along with the examples provided.

[0020] The technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the protection scope of the present application.

[0021] In addition, all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship, movement status, etc. between each component in a specific posture (as shown in the drawings). When the specific posture changes, the directional indications will also change accordingly.

[0022] In the present application, unless specifically specified or limited otherwise, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, an internal communication between two elements, or an interaction between two elements, unless specifically limited otherwise. Those skilled in the art can understand the specific meaning of the above terms in the present application based on the specific situation.

[0023] In addition, in the embodiments of the present application, descriptions such as "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, the features limited by "first" and "second" can explicitly or implicitly include at least one such feature. Also, "and / or" appearing throughout the specification includes three schemes. Taking "A and / or B" as an example, it means including the technical solution of A, or the technical solution of B, or the technical solution that satisfies both A and B. Further, the technical solutions between the embodiments can be combined with each other, but it must be based on what can be achieved by those skilled in the art. If contradictions or impossibilities occur in the combination of technical solutions, such a combination of technical solutions does not exist and should not be considered within the scope of protection required by the present application.

[0024] Referring to FIGS. 1 to 3, the present application proposes a motor, including a stator core 11 provided with a stator slot 111, and a winding 12 wound around the stator core 11 and located in the stator slot 111, and a rotor including a rotor core 21 provided with a plurality of per-pole magnet slots 23 and a plurality of permanent magnets 22 located in the per-pole magnet slots 23. When 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 hcj, the included angle of the per-pole magnet slot 23 is α, and the thickness along the magnetization direction of the permanent magnet 22 is h, then hcj ≦ 1800 kA / m, 11 × α / hcj ≦ h ≦ 50 × α / hcj, and α / hcj is the demagnetizing field coefficient.

[0025] The motor of the technical solution of this application comprises a stator and a rotor, the stator including a stator core 11 on which a stator rod 111 is provided and a winding 12 wound around the stator core 11 and located within the stator rod 111, the rotor including a rotor core 21 on which a plurality of pole magnet slots 23 are provided and a plurality of permanent magnets 22 located within the pole magnet slots 23, the number of slots of the stator rod 111 is 15, the number of poles of the rotor is 10, the defined intrinsic coercivity of the permanent magnet 22 is hcj (unit kA / m), the angle between the pole magnet slots is α (unit °), and the thickness of the permanent magnet 22 along the magnetization direction is h (unit m) If m), then hcj ≤ 1800 kA / m, and further restrict the relationship between hcj, α, and h to 11 × α / hcj ≤ h ≤ 50 × α / hcj, where α / hcj is the demagnetizing coefficient. The technical solution of this application provides a 15-slot 10-pole variable frequency motor for compressors, the demagnetizing capability of the slot pole structure of the motor is superior to that of current household air conditioner motor structures, and at the same time, by adjusting the relationship between the demagnetizing coefficient and the thickness of the magnets, it is possible to reduce the use of heavy rare earth elements, lower the cost of magnets, and at the same time improve the cost performance of the motor, while ensuring that demagnetization meets the requirements.

[0026] The variable frequency motors currently used in household air conditioner compressors have status rod 111 slots of 6, 9, or 12, and rotor poles of 4, 6, or 8. The number of slots in the status rod 111 of the motor directly affects the motor's demagnetizing ability. In other words, as the number of status rods of the motor increases, the motor's demagnetizing ability improves, which in turn improves its demagnetizing resistance. In this application, the status rod 111 has 15 slots and the rotor has 10 poles, which further improves the motor's demagnetizing ability and demagnetizing resistance compared to current household air conditioners.

[0027] The following points need to be explained: First, the magnetized and saturated rotor is placed at room temperature. Next, the magnetic flux φ0 of the rotor is measured. Then, the rotor with the initial magnetic flux is placed in a constant temperature box for more than 4 hours, setting the temperature of the constant temperature box to a specified temperature of 130°C. Next, the test DC motor is connected to a DC power supply, and the demagnetizing current (35A, 40A, 45A, etc.) is set to a predetermined demagnetizing current value. Once ready, the rotor is removed from the constant temperature box, the demagnetizing test fixture is attached, and the rotor is rotated once under the DC demagnetizing current. After completion, the rotor is placed at room temperature for more than 4 hours, and then the temperature of the rotor and the magnetic flux φ1 after demagnetization are measured. Finally, the demagnetization rate is calculated using the formula (where φi is the same temperature as φ0 that needs to be used in the calculation): Demagnetization rate = (φi - φ0) / φ0 × 100%.

[0028] Furthermore, the demagnetization rate of the rotor is affected by current and temperature, and as can be seen from the comparison between the motor of this application and the reference value under different current conditions shown in Figure 4, the demagnetization rate of the motor of this application is very close to the reference value under different current conditions. Therefore, the motor of this application can meet the needs of compressors.

[0029] Furthermore, referring to Figure 5, the efficiency of the motor of this application at different rotational speeds is very close to the reference value, and as can be seen from this, the motor of this application can meet the needs of a compressor.

[0030] Referring to Figures 1 and 3, in one embodiment, the pole magnet slots 23 are arranged in a V shape, and 90° ≤ α < 180°. When α is 90° or less, or α > 180°, the permanent magnet 22 is difficult to magnetize, and the utilization efficiency of the permanent magnet 22 is relatively low. Therefore, when 90° ≤ α < 180°, the utilization efficiency of the permanent magnet 22 can be increased.

[0031] Furthermore, since 100° ≤ α < 130°, the utilization efficiency of the permanent magnet 22 can be further improved by further restricting the numerical range of α.

[0032] Referring to Figure 2, in other embodiments, α = 180°, meaning that the pole magnet slots 23 are arranged in a straight line. In this case, the permanent magnets 22 are more easily magnetized, and the utilization efficiency of the permanent magnets 22 is increased, thereby further improving the performance of the motor.

[0033] In other embodiments, the structure of the pole magnet slot 23 can be set to various shapes such as U-shaped slots, W-shaped slots, or I-shaped slots. By setting the pole magnet slot 23 to various shapes such as V-shaped slots, U-shaped slots, W-shaped slots, straight slots, or I-shaped slots, it becomes possible to install permanent magnets 22 of different structures within them. This makes the motor manufacturing process more flexible, expands the range of options, meets various application scenarios, and broadens the scope of product application.

[0034] In one embodiment, the mass percentage range of heavy rare earth elements in the permanent magnet 22 is 0 to 1.5%, or the mass percentage range of dysprosium and / or terbium in the permanent magnet 22 is 0 to 1.5%. Dysprosium and terbium belong to the 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 magnitude of the intrinsic coercivity (HCJ) of the permanent magnet 22. Accordingly, in one embodiment, limiting the mass percentage range of dysprosium and / or terbium in the permanent magnet 22 to 0-1.5% is advantageous in reducing the use of dysprosium and / or terbium while ensuring good demagnetization resistance of the motor, and is also advantageous in reducing the manufacturing cost of the motor and improving the cost performance of the motor. In another embodiment, limiting the mass percentage range of heavy rare earth elements in the permanent magnet 22 to 0-1.5% is advantageous in reducing the use of heavy rare earth elements while ensuring good demagnetization resistance of the motor, and is also advantageous in reducing the manufacturing cost of the motor and improving the cost performance of the motor.

[0035] In other embodiments, the mass percentage of dysprosium and / or terbium in the permanent magnet 22 is 0, meaning the permanent magnet 22 does not contain the heavy rare earth element dysprosium, thereby reducing the consumption of the heavy rare earth element dysprosium by the permanent magnet 22, which is advantageous for energy saving. In other embodiments, the mass percentage of terbium in the permanent magnet 22 is 0, meaning the permanent magnet 22 does not contain the heavy rare earth element terbium. This reduces the consumption of the heavy rare earth element terbium by the permanent magnet 22, which is advantageous for energy saving. In another embodiment, the sum of the mass percentages of dysprosium and terbium in the permanent magnet 22 is 0, meaning the permanent magnet 22 does not contain the heavy rare earth elements dysprosium and terbium. This reduces the consumption of the heavy rare earth elements dysprosium and terbium by the permanent magnet 22, which is advantageous for sustainable resource development, energy saving, and reducing the manufacturing cost of motors, making it suitable for widespread adoption and application.

[0036] To make it easier to understand, the mass percentage of dysprosium and / or terbium in the permanent magnet 22 may be other values, for example, 0.005%, 0.01%, and 0.025%. Furthermore, the permanent magnet 22 is a neodymium iron boron permanent magnet, and neodymium iron boron magnets have excellent magnetic properties and can meet the needs of motor use.

[0037] In one embodiment, the range of the residual magnetic flux density Br of the permanent magnet 22 is 1.28T to 1.5T. Residual magnetic flux density refers to the surface magnetic field remaining after the permanent magnet 22 has been magnetized to a technical saturation state and the external magnetic field has been removed, where Br is the residual magnetic induction strength. By appropriately setting the residual magnetic flux density, it is shown that for the same magnetic load, the larger the residual magnetic flux density Br value, the less rare earth elements can be used in the permanent magnet 22, further reducing the manufacturing cost of the motor. At the same time, appropriately setting the residual magnetic flux density is advantageous in reducing iron loss and further improving the efficiency of the motor. Specifically, the residual magnetic flux density of the permanent magnet 22 is 1.28T, 1.32T, or 1.5T, where T is the unit Tesla.

[0038] In this embodiment, if the outer diameter of the stator is D, then 85 mm ≤ D ≤ 200 mm. By limiting the range of the stator's outer diameter, the motor's demagnetization resistance is improved, the amount of rare earth elements used is reduced, and the production and manufacturing costs of the motor are lowered, thereby improving the motor's cost performance. At the same time, a stator outer diameter in the range of 85 to 200 mm can satisfy the requirements for a compressor motor.

[0039] In one embodiment, if the inner diameter of the stator is Di and the outer diameter of the stator is D, then 0.45 ≤ Di / D ≤ 0.65. Furthermore, by limiting the inner and outer diameters of the stator to the range of 0.45 to 0.65, the moment of inertia can be increased, which is advantageous for the stable low-frequency energy efficiency performance of the compressor using the motor. At the same time, the motor has optimal demagnetization capability, thereby achieving higher system energy efficiency. Simultaneously, the amount of rare earth elements used is reduced, further reducing the production and manufacturing costs of the motor, thereby improving the cost performance of the motor.

[0040] In one embodiment, the stator core 11 is formed by laminating multiple stator punching sheets, and the rotor core 21 is formed by laminating rotor punching sheets. In one embodiment, the rotor core 21 and the stator core 11 may be made of different materials or have different shapes, thereby meeting the needs of different processing processes for the stator and rotor. It is advantageous to select appropriate punching sheets according to the performance requirements of the motor to form the rotor core 21 and stator core 11, further ensuring good electrode performance and broadening the range of applications for the motor. In another embodiment, the stator punching sheets laminated on the stator core 11 and the rotor punching sheets laminated on the rotor core 21 are the same, thereby facilitating mass production of punching sheets and reducing manufacturing costs.

[0041] In one embodiment, the perforated sheet is a soft magnetic material perforated sheet, and the soft magnetic material can achieve a large magnetization strength with a smaller external magnetic field. This soft magnetic material has low coercivity and high permeability, which is advantageous in reducing losses in the stator core 11 and / or rotor core 21, i.e., reducing the iron loss of the motor, and further advantageous in improving the performance of the motor. Specifically, the perforated sheet is a silicon steel sheet, but as can be understood, the perforated sheet may be made of other materials.

[0042] Many factors influence eddy current loss, including the cross-sectional area and thickness of the magnetic material, the frequency of the induced electromotive force, and the magnetic flux density. By setting the rotor core 21 and stator core 11 to be formed by laminating multiple layers of rotor punching sheets and stator punching sheets that are insulated from each other, eddy currents can be suppressed within each layer of rotor punching sheet or stator punching sheet, thereby reducing the eddy current loss. In other words, by avoiding the conduction of eddy currents between layers, the eddy current loss of the entire rotor core 21 and stator core 11 can be significantly reduced. Specifically, the stator core 11 and rotor core 21 are usually silicon steel sheets, and an insulating surface layer may be formed on them with a unique coating film, or the motor manufacturer may apply an insulating paint to a punching sheet without a coating film to form an insulating surface layer, or the motor manufacturer may oxidize the punching sheet to form an insulating surface layer.

[0043] In related technologies, sufficient crimping strength is required for the motor core to prevent loosening or misalignment of the rotor core 21, or to prevent deformation of the rotor core 21 due to interlayer offset during the process of winding the coil windings 12. To ensure that the motor core has sufficient crimping strength, in this embodiment, a plurality of rivet holes 24 are provided in the rotor core 21. The fitting of the rivets and rivet holes 24 can satisfy the fixing strength between the silicon steel sheets, thereby avoiding the problem of interlayer misalignment of the silicon steel sheets in subsequent processing processes.

[0044] One point that needs to be explained is that, in order to mitigate or avoid the interlayer eddy current conduction problem caused by this crimped structure, the rotor punching sheets can be joined using adhesive instead of the crimping method. This prevents damage to the insulating surface layer of the silicon steel sheet in the rivet holes 24, thereby avoiding the problem of interlayer eddy current conduction. However, due to the high cost of the adhesive and the low production efficiency of the production line, this method is not applied to motors for air conditioner compressors.

[0045] In this embodiment, the rotor core 21 is further provided with shaft holes and flow holes. The shaft holes are used to attach the transmission shaft, thereby moving the object to be transmitted to rotate. When the motor is used for a long period of time, its temperature tends to rise, which can lead to demagnetization of the permanent magnets 22, potentially causing the permanent magnets 22 to lose their magnetism or their magnetic force to decrease. Therefore, in this embodiment, by providing flow holes in the rotor core 21, a coolant can circulate within the flow holes, thereby lowering the temperature of the rotor core 21. This allows the temperature of the permanent magnets 22 to be maintained within an optimal range, improving the performance of the motor.

[0046] This application further proposes a compressor equipped with a motor, the specific structure of which is described in the above embodiments, and since the compressor of this application employs all of the technical solutions of all the above embodiments, it has at least all of the beneficial effects brought about by the technical solutions of the above embodiments, but a detailed explanation is omitted here.

[0047] This application further proposes a cooling device equipped with the above-mentioned compressor, which may be a refrigerator, freezer, air conditioner, or other device having a cooling function, but is not limited thereto. The specific structure of the compressor is described in the above-mentioned embodiments, and since the cooling device of this application employs all of the technical solutions of all the above-mentioned embodiments, it has at least all of the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, but a detailed explanation is omitted here.

[0048] The above description is merely an example of an optional embodiment of this application and does not limit the scope of the patent provided herein. All equivalent structural transformations based on the inventive concept of this application, performed using the specifications and drawings of this application, or applied directly or indirectly in other related technical fields, are included within the scope of the patent protection of this application. [Explanation of symbols]

[0049] 11 Stator Core 111 Status Lot 12 windings 21 Rotor Core 22 Permanent Magnets 23 Pole Magnet Slots 24 rivet holes

Claims

1. A stator comprising a stator core on which a status rod is provided, and a winding wound around the stator core and located at the status rod, The rotor comprises a rotor core having multiple pole magnet slots, and a rotor including multiple permanent magnets located within the pole magnet slots, A motor in which, given that the number of slots in the status lot is 15, the number of poles in the rotor is 10, the intrinsic coercivity of the permanent magnet is hcj, the angle between each pole magnet slot is α, and the thickness of the permanent magnet along the magnetization direction is h, then hcj ≤ 1800 kA / m, and 11 × α / hcj ≤ h ≤ 50 × α / hcj, where α / hcj is the demagnetizing coefficient.

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

3. The motor according to claim 2, wherein 100° ≤ α < 130°.

4. A motor according to any one of claims 1 to 3, wherein α = 180°.

5. The motor according to any one of claims 1 to 4, wherein the mass percentage range of dysprosium and / or terbium in the permanent magnet is 0 to 1.5%, and the mass percentage range of heavy rare earth elements in the permanent magnet is 0 to 1.5%.

6. The motor according to any one of claims 1 to 5, wherein the range of the residual magnetic flux density Br of the permanent magnet is 1.28T to 1.5T.

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

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

65.

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

10. Cooling equipment including the compressor described in claim 9.

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