Motors, compressors, and cooling equipment

Abstract

This application discloses a motor, a compressor, and a cooling device. The motor includes a stator and a rotor, the stator includes a stator core and windings, the stator core is provided with a stator rod, the stator core includes a stator yoke and stator teeth, the stator teeth are connected to the stator yoke, the windings are wound around the stator teeth and located within the stator rod, the rotor includes a rotor core and permanent magnets, the rotor core is provided with magnet slots, the permanent magnets are located in the magnet slots, and if the outer and inner diameters of the stator core are D1 and D2, respectively, the thickness of the stator yoke is t, the width of the magnet slots is b, the thickness of the magnet slots is h, the number of poles of the rotor is 2p, and the number of permanent magnets is N, then 4.3 ≤ t ≤ 7.0, 0.577 ≤ D2 / D1 ≤ 0.6, and 1.3 ≤ b × h × 2p × N / 1000 ≤ 3.5.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with the application number 202311133527.7 filed on September 4, 2023, and all its contents are incorporated herein by reference.

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

Background Art

[0003] In conventional compressor motors, in order to reduce costs and improve efficiency, the power density of the motor is increased to the limit. However, if the power density of the motor is too high, it may lead to reliability problems such as excessive electrical density and temperature rise of the motor, and a decrease in overload capacity.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The main object of this application is to provide a motor, a compressor, and a cooling device by reasonably designing the dimensional relationship between the stator and the rotor to ensure the reliability of the motor, improve the overload capacity and efficiency of the motor without significantly increasing the cost.

Means for Solving the Problems

[0005] To achieve the above objective, the motor proposed in this application includes a stator core and windings, wherein the stator core is provided with a stator rod, the stator core includes a stator yoke and stator teeth, the stator teeth are connected to the stator yoke, the windings are wound around the stator teeth and located within the stator rod, the motor includes a rotor core and permanent magnets, wherein the rotor core is provided with magnet slots, the permanent magnets are located in the magnet slots, and if 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 slots is b, the thickness of the magnet slots is h, the number of poles of the rotor is 2p, and the number of permanent magnets is N, then 4.3≦t≦7.0, 0.577≦D2 / D1≦0.6, and 1.3≦b×h×2p×N / 1000≦3.5.

[0006] In one embodiment, 12 status lots are provided.

[0007] In one embodiment, the number of poles 2p of the rotor is 8, or the number of poles 2p of the rotor is 10.

[0008] In one embodiment, N=2p or N=4p.

[0009] In one embodiment, 70mm ≤ D1 ≤ 150mm.

[0010] In one embodiment, 1.2 mm ≤ h ≤ 2.5 mm.

[0011] In one embodiment, the rotor is provided with passage holes for the refrigerant to flow through.

[0012] This application also proposes a compressor including the motor.

[0013] This application also proposes a cooling device including the above-mentioned compressor. [Brief explanation of the drawing]

[0014] To more clearly explain the technical solutions in the embodiments of this application or related technologies, the drawings necessary for describing the embodiments or related technologies will be briefly described below. However, the drawings in the following description are only a few embodiments of this application, and it will be obvious to those skilled in the art that other drawings can be obtained based on the configurations shown in these drawings without any creative effort.

[0015] [Figure 1] This is a cross-sectional view of one embodiment of the motor of this application. [Figure 2] This is an annotated version of Figure 1 with each parameter added. [Figure 3] This is a comparison diagram of the torque of the motors of this application. [Figure 4] This is a comparative diagram of the motor efficiencies of the present application. [Modes for carrying out the invention]

[0016] The achievement of the objectives of this application, its functional features, and advantages will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0017] The technical solutions in the embodiments of this application will be described clearly and completely below with reference to the drawings in the embodiments of this application, although it is clear that the embodiments described are only a part of the embodiments of this application and not all of them. All other embodiments that a person skilled in the art could obtain without creative work based on the embodiments of this application are within the scope of protection of this application.

[0018] In the embodiments of this application, all directional indicators (e.g., up, down, left, right, front, back, etc.) are used solely to describe the relative positional relationships and motion conditions between each component in a specific orientation (as shown in the drawings). If that specific orientation changes, the directional indicators will also change accordingly.

[0019] In this application, unless otherwise explicitly stated and limited, terms such as “connection,” “fixed,” etc., should be understood in a broad sense. For example, “fixed” may be a fixed connection, a detachable connection, or an integral connection. It may be a mechanical connection or an electrical connection. Unless otherwise explicitly stated, it may be a direct connection, an indirect connection via an intermediate medium, an internal communication between two elements, or an interaction relationship between two elements. The specific meaning of the above terms in this application can be understood by those skilled in the art depending on the context.

[0020] Furthermore, descriptions of "first," "second," etc. in this application are for explanatory purposes only and should not be understood as indicating or implying their relative importance or the number of technical features to be shown. Accordingly, features limited by "first," "second," etc., may explicitly or implicitly include at least one such feature. Also, "and / or" in the whole text includes three forms, taking A and / or B as an example, including technical solution A, technical solution B, and technical solution satisfying both A and B simultaneously. Furthermore, the technical solutions of each embodiment may be combined with each other, but must be based on what a person skilled in the art can achieve, and if a combination of technical solutions is mutually contradictory or unrealistic, such a combination of technical solutions should be considered not to exist and not to be included in the scope of protection claimed in this application.

[0021] Referring to Figures 1 and 2, the present application includes a stator core 11 and a winding 12, wherein the stator core 11 is provided with a stator rod 113, the stator core 11 includes a stator yoke 111 and stator teeth 112, the stator yoke 111 is provided in an annular shape, the stator teeth 112 are provided at intervals on the inner circumferential surface of the stator yoke 111, and the winding 12 is wound around the stator teeth 112 and located within the stator rod 113, and the stator and rotorco We propose a motor that includes a rotor core 21 and a permanent magnet, wherein the rotor core 21 is provided with magnet slots 22, and the permanent magnet includes a rotor located in the magnet slots 22, where D1 and D2 are the outer and inner diameters of the stator core 11, respectively, t is the thickness of the stator yoke 111, b is the width of the magnet slots 22, h is the thickness of the magnet slots 22, 2p is the number of poles of the rotor, and N is the number of permanent magnets, such that 4.3 ≤ t ≤ 7.0, 0.577 ≤ D2 / D1 ≤ 0.6, and 1.3 ≤ b × h × 2p × N / 1000 ≤ 3.5.

[0022] The motor in the technical solution of this application includes a stator and a rotor. The stator includes a stator core 11 and a winding 12. A stator slot 113 is provided in the stator core 11. 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 is located within the stator slot 113. The rotor includes a rotor core 21 and permanent magnets. A magnet slot 22 is provided in the rotor core 21. The permanent magnets are located within the magnet slot 22. Further, if 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, and the number of permanent magnets is N, then 0.577 ≦ D2 / D1 ≦ 0.6 and 1.3 ≦ b×h×2p×N / 1000 ≦ 3.5. By reasonably designing the dimensions of the stator and the rotor, the reliability of the motor is ensured, the cost is not significantly increased, and the overload capacity and efficiency of the motor are improved.

[0023] Also, by limiting the inner and outer diameters of the stator within the range of 0.577 to 0.6, the moment of inertia can be increased, which is beneficial for the stable exertion of the low-frequency energy efficiency of the compressor using this motor. Moreover, the motor is given an optimal demagnetization ability, further improving the energy efficiency of the system. Additionally, the amount of rare earth elements used is further reduced, reducing the production cost of the motor, thereby improving the cost performance of the motor. Furthermore, it is clear from the experimental data in FIGS. 3 and 4 that in this application, when the dimensions of the stator and the rotor are reasonably set, when the current exceeds 6A, in this embodiment, the torque significantly exceeds the reference value, and at each rotational speed of 30 rps / 60 rps / 90 rps, the motor efficiency of this embodiment significantly exceeds the reference value.

[0024] The stator core 11 includes a plurality of stator punching sheets stacked in sequence, the stator slots 113 are provided on the stator punching sheets, the rotor core 21 includes a plurality of rotor punching sheets stacked in sequence, the magnet slots 22 are provided on the rotor punching sheets. By providing a plurality of stator punching sheets and rotor punching sheets, when processing the stator core 11 and the rotor core 21, it is only necessary to process a plurality of stator punching sheets or rotor punching sheets and assemble these plurality of stator punching sheets and rotor punching sheet parts into the stator core 11 and the rotor core 21. The difficulty of processing the stator punching sheet and rotor punching sheet parts is lower than that of processing the finished products of the stator core 11 and the rotor core 21, which facilitates the automatic production of the stator core 11 and the rotor core 21 by an automatic production line, thereby reducing the production cost.

[0025] In one embodiment, the rotor core 21 and the stator core 11 may have different materials or shapes, thereby satisfying the needs of various processing processes of the stator and the rotor, and being advantageous for manufacturing the rotor core 21 and the stator core 11 using appropriate punching sheets according to the performance requirements of the motor. Thereby, while ensuring good performance of the electrode, the application range of the motor is also expanded. In another embodiment, making the stator punching sheet constituting the stator core 11 by lamination and the rotor punching sheet constituting the rotor core 21 by lamination the same is advantageous for mass production of the punching sheet and reduction of manufacturing cost.

[0026] Furthermore, the perforated sheet is made of a soft magnetic material, and soft magnetic materials can achieve relatively large magnetization strength with a relatively small external magnetic field, and have low coercivity and high permeability, which is advantageous in reducing losses in the stator core 11 and / or rotor core 21, i.e., iron loss of the motor, and further advantageous in improving motor performance. Specifically, the perforated sheet is a silicon steel sheet, but it is understood that the perforated sheet may be made of other materials.

[0027] Numerous 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 constructing the rotor core 21 and stator core 11 with multiple layers of rotor and stator punching sheets that are insulated from each other, eddy currents can be suppressed in each layer of the rotor or stator punching sheets, thereby reducing eddy current loss. In other words, by preventing interlayer eddy current conduction, the overall eddy current loss of the rotor core 21 and stator core 11 can be significantly reduced. Specifically, the stator core 11 and rotor core 21 are usually composed of silicon steel sheets, and an insulating surface layer may be formed with a coating specific to the silicon steel sheet, or the motor manufacturer may apply an insulating paint to a punching sheet without a coating to form an insulating surface layer, or the motor manufacturer may form an insulating surface layer by oxidizing the punching sheet.

[0028] In related technologies, sufficient stacking rivet strength is required for the motor core to prevent defects such as loosening of sheets or misalignment between layers from occurring in the rotor core 21, or to prevent the rotor core 21 from changing due to misalignment between the perforated sheets of the rotor core 21 during the winding process of the coil winding 12 of the rotor core 21. In this embodiment, multiple rivet holes 23 are provided in the rotor core 21 to ensure that the motor core has sufficient stacking rivet strength. The fixing strength between the silicon steel sheets is satisfied through the fitting of the rivets and rivet holes 23, thereby preventing the problem of misalignment between the silicon steel sheets in subsequent processing steps.

[0029] Furthermore, in order to reduce, or even avoid, the interlayer eddy current conduction problem caused by such stacking rivet structures, the rotor punching sheet can be attached with adhesive instead of stacking rivets. This prevents damage to the insulating surface layer of the silicon steel sheet in the rivet holes 23 and avoids the problem of interlayer eddy current conduction. However, the adhesive is expensive and has low production efficiency in the production line, so its application to motors for air conditioner compressors has not been achieved.

[0030] In this embodiment, 12 status rods 113 are provided. Currently, the number of status rods 113 in variable frequency motors used in compressors for household air conditioners is 6 or 9. Firstly, the number of status rods 113 determines the arrangement of the stator windings 12 and further affects the magnetic field distribution of the motor. A larger number of status rods 113 results in a more uniform magnetic field distribution, reducing magnetic field non-uniformity, thereby improving motor efficiency and performance. Secondly, increasing the number of status rods 113 within a certain range can reduce the decrease in magnetic field saturation. When current flows through the stator windings 12, the core becomes saturated by the magnetic field, thereby reducing motor efficiency and performance. If the number of status rods 113 is increased too much, the motor's output power and efficiency may decrease. Also, if the number of status rods 113 is too small, harmonic magnetic fields may be generated, potentially causing motor vibration and noise. Therefore, increasing the number of status rods 113 can reduce the generation of harmonic magnetic fields and improve the motor's operating stability and quietness. Therefore, in this embodiment, by providing 12 status rods 113, various motor performances are improved, noise generation is reduced, and the cost performance of the motor is improved.

[0031] In this embodiment, the number of poles 2p of the rotor is 8, or the number of poles 2p of the rotor is 10. Currently, the number of poles of rotors commonly used in homes is generally 4 or 6. The rotational speed of a motor is closely related to the number of poles of the rotor; generally, the more poles there are, the higher the rotational speed and the higher the motor efficiency. A larger number of poles results in a smaller rotational diameter, higher electromotive force and magnetic field frequency per phase, a larger electromotive force per cycle, and a higher no-load rotational speed of the motor. Under load, the no-load rotational speed is limited by the allowable heat loss, so the rotational speed under load is lower and limited by the allowable load conditions, and power consumption decreases accordingly. Therefore, in this embodiment, by setting the number of poles to 8 or 10, motor efficiency is improved and motor power consumption is reduced.

[0032] In this embodiment, N=2p or N=4p. The number of rotor poles refers to the number of magnetic poles in the motor rotor. The number of magnetic poles in a motor determines the motor's performance and characteristics. A larger number of rotor poles results in greater motor torque but lower rotational speed, while a smaller number of rotor poles results in higher rotational speed but lower torque. Therefore, by setting the number of rotor poles to 2p and 4p, both the torque requirement and the rotational speed requirement of the compressor can be met, further improving the motor's cost-effectiveness.

[0033] In this embodiment, 70mm ≤ D1 ≤ 150mm. If D1 is the outer diameter of the stator core 11, then 70mm ≤ D1 ≤ 150mm. By limiting the range of the outer diameter of the stator punching sheet, the demagnetization resistance of the motor can be increased, the amount of rare earth elements used can be further reduced, the production cost of the motor can be reduced, and thereby the cost performance of the motor can be improved. In addition, if the outer diameter of the stator is in the range of 70 to 150, the requirements for a compressor motor can be met.

[0034] In this embodiment, 1.2 mm ≤ h ≤ 2.5 mm. Since the magnet slot 22 and the permanent magnet are fitted in the thickness direction, when h ≤ 1.2 mm, i.e., when the thickness of the permanent magnet is relatively thin, the magnetic flux density decreases, the motor output power decreases, and the motor efficiency further decreases. When x ≥ 2.5 mm, i.e., when the thickness of the permanent magnet is relatively thin, the phenomenon of magnetic circuit saturation occurs, the magnetic circuit loss increases, and the motor efficiency decreases. Therefore, by controlling the thickness of the magnet slot 22 and the permanent magnet to 1.2 mm to 2.5 mm, the motor output power meets the compressor requirements without making the permanent magnet thickness too thick, and the magnetic circuit loss is further reduced, improving the motor efficiency.

[0035] Numerous 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 constructing the rotor core 21 and stator core 11 with multiple layers of rotor and stator punching sheets that are insulated from each other, eddy currents can be suppressed in each layer of the rotor or stator punching sheets, thereby reducing eddy current loss. In other words, by preventing interlayer eddy current conduction, the overall eddy current loss of the rotor core 21 and stator core 11 can be significantly reduced. Specifically, the stator core 11 and rotor core 21 are usually composed of silicon steel sheets, and an insulating surface layer may be formed with a coating specific to the silicon steel sheet, or the motor manufacturer may apply an insulating paint to a punching sheet without a coating to form an insulating surface layer, or the motor manufacturer may form an insulating surface layer by oxidizing the punching sheet.

[0036] In related technologies, sufficient stacking rivet strength is required for the motor core to prevent defects such as loosening of sheets or misalignment between layers from occurring in the rotor core 21, or to prevent the rotor core 21 from changing due to misalignment between the perforated sheets of the rotor core 21 during the winding process of the coil winding 12 of the rotor core 21. In this embodiment, multiple rivet holes 23 are provided in the rotor core 21 to ensure that the motor core has sufficient stacking rivet strength. The fixing strength between the silicon steel sheets is satisfied through the fitting of the rivets and rivet holes 23, thereby preventing the problem of misalignment between the silicon steel sheets in subsequent processing steps.

[0037] Furthermore, in order to reduce, or even avoid, the interlayer eddy current conduction problem caused by such stacking rivet structures, the rotor punching sheet can be attached with adhesive instead of stacking rivets. This prevents damage to the insulating surface layer of the silicon steel sheet in the rivet holes 23 and avoids the problem of interlayer eddy current conduction. However, the adhesive is expensive and has low production efficiency in the production line, so its application to motors for air conditioner compressors has not been achieved.

[0038] In this embodiment, the rotor core 21 is further provided with a shaft hole 25 and a ventilation hole 24. The shaft hole 25 is used to attach a transmission shaft and rotate the object to be transmitted. When a motor is used for a long time, its temperature tends to rise, which can easily cause demagnetization of the permanent magnets, resulting in loss of magnetism or a decrease in magnetism. Therefore, in this embodiment, the rotor core 21 is provided with a ventilation hole 24, and a coolant is circulated through the ventilation hole 24 to lower the temperature of the rotor core 21 with the coolant, thereby maintaining the permanent magnets within an optimal temperature range and further improving the performance of the motor.

[0039] In one embodiment, the mass percentage range of heavy rare earth elements in the permanent magnet is 0 to 1.5%, or the mass percentage range of dysprosium and / or terbium in the permanent magnet is 0 to 1.5%. Dysprosium and terbium are heavy rare earth elements that are national strategic resources, and the mass percentage of heavy rare earth elements in a permanent magnet is positively correlated with the magnitude of the intrinsic coercivity (HCJ) of the permanent magnet. Therefore, limiting the mass percentage range of dysprosium and / or terbium in the permanent magnet to 0 to 1.5% is advantageous in reducing the amount of dysprosium and / or terbium used while ensuring good demagnetization resistance of the motor, and further advantageous in reducing the manufacturing cost of the motor and improving the cost performance of the motor. On the other hand, limiting the mass percentage range of heavy rare earth elements in permanent magnets to 0-1.5% is advantageous in reducing the amount of heavy rare earth elements used while ensuring good demagnetization resistance of the motor, and furthermore, it is advantageous in reducing the manufacturing cost of the motor and improving the cost performance of the motor.

[0040] In another embodiment, the mass percentage of dysprosium and / or terbium in the permanent magnet is 0. On the one hand, if the mass percentage of dysprosium in the permanent magnet is 0, that is, if the permanent magnet does not contain the heavy rare earth element dysprosium, it reduces the consumption of the heavy rare earth element dysprosium by the permanent magnet, which is advantageous for energy saving. On the other hand, if the mass percentage of terbium in the permanent magnet is 0, that is, if the permanent magnet does not contain the heavy rare earth element terbium, it reduces the consumption of the heavy rare earth element terbium by the permanent magnet, which is advantageous for energy saving. Furthermore, if the sum of the mass percentages of dysprosium and terbium in the permanent magnet is 0, that is, if the permanent magnet does not contain the heavy rare earth elements dysprosium and terbium, it reduces the consumption of the heavy rare earth elements dysprosium and terbium by the permanent magnet, which is advantageous for the sustainable development of resources, saves energy, reduces the manufacturing cost of motors, and is suitable for the widespread use and application of permanent magnets.

[0041] The mass percentage of dysprosium and / or terbium in a permanent magnet may be other values; for example, it is understood that the mass percentage of dysprosium and / or terbium in a permanent magnet may be 0.005%, 0.01%, 0.025%, etc. Furthermore, the permanent magnet is a neodymium-iron-boron permanent magnet that has excellent magnetic properties and can meet the requirements for use in motors.

[0042] Specifically, the range of the residual magnetic flux density Br of the permanent magnet is 1.28T to 1.5T. Here, residual magnetic flux density refers to the surface field remaining after the permanent magnet has been magnetized to technical saturation and the external magnetic field has been removed. Br is the residual magnetic induction strength. By appropriately setting the residual magnetic flux density, a higher residual magnetic flux density Br value indicates that less rare earth elements are used in the permanent magnet under the same magnetic load, further reducing the manufacturing cost of the motor. Furthermore, appropriately setting the residual magnetic flux density is advantageous in reducing iron loss and improving motor efficiency. Specifically, the residual magnetic flux density of the permanent magnet is 1.28T, or 1.32T, or 1.5T, where T is the unit Tesla.

[0043] This application also proposes a compressor including a motor, and the specific structure of the motor is described in the above embodiments. The compressor of this application employs all of the technical solutions of the above embodiments and therefore has at least all of the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0044] This application also proposes a cooling device including the compressor described above. Here, the cooling device may be, but is not limited to, a refrigerator, freezer, air conditioner, or other cooling functions. For the specific structure of the compressor, refer to the embodiments described above. The cooling device of this application employs all of the technical solutions of the embodiments described above and therefore has at least all of the beneficial effects brought about by the technical solutions of the embodiments described above. This will not be explained in detail here.

[0045] The above description is merely an example of any embodiment of this application and does not limit the scope of this application. Any equivalent structural transformations or direct / indirect uses in other related technical fields based on the concept of this application and using the contents of the specification and drawings of this application shall all be within the scope of this application. [Explanation of symbols]

[0046] 11 Stator Core 111 Stater York 112 Status Teeth 113 Status Lot 12 windings 21 Rotor Core 22 Magnetic Slots 23 rivet holes 24 Flow hole 25 Shaft hole

Claims

1. A stator comprising a stator core and windings, wherein a stator rod is provided on the stator core, and the stator core comprises a stator yoke and stator teeth, the stator teeth being connected to the stator yoke, and the windings being wound around the stator teeth and located within the stator rod, A rotor core and a permanent magnet are included, wherein the rotor core is provided with a magnet slot, and the permanent magnet is located in the magnet slot, A motor in which, if the outer and inner diameters 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, and the number of permanent magnets is N, then 4.3 ≤ t ≤ 7.0, 0.577 ≤ D2 / D1 ≤ 0.6, and 1.3 ≤ b × h × 2p × N / 1000 ≤ 3.

5.

2. The motor according to claim 1, wherein twelve status slots are provided.

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

4. A motor according to any one of claims 1 to 3, wherein N = 2p or N = 4p.

5. A motor according to any one of claims 1 to 4, wherein 70 mm ≤ D1 ≤ 150 mm.

6. A motor according to any one of claims 1 to 5, wherein 1.2 mm ≤ h ≤ 2.5 mm.

7. The motor according to any one of claims 1 to 6, wherein the rotor is provided with a passage hole for the flow of a refrigerant.

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

9. A cooling device including the compressor described in claim 8.

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