Motor, compressor and air conditioner

Abstract

The invention provides a motor, a compressor and an air conditioner, the motor comprises a stator, a rotor and a stator winding, and the wiring mode of the stator winding can be switched between a star connection wiring mode and an angle connection wiring mode; the stator is provided with stator teeth which are uniformly arranged along the circumferential direction, the stator winding comprises coil windings which are wound on the stator teeth, and each coil winding is provided with N turns of coils which are connected in series; the motor is a three-phase motor, m parallel branches are arranged in a single-phase stator winding of the motor, and if no parallel branch exists in the single-phase stator winding of the motor, m is equal to 1; the number of poles of the rotor is P, the width of magnetic steel in a single magnetic pole of the rotor is W, the thickness of the magnetic steel is D, and the axial height of the magnetic steel is H; 0.5 < = N * N / m / m / (W * D * H * P) < = 1.2, and the units of W, D and H are millimeter. According to the invention, the rotating speed fluctuation of the motor adopting the winding cutting technology can be reduced, and the motor efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a motor, a compressor, and an air conditioner. Background Technology

[0002] Switching winding technology refers to the ability to switch the stator winding connection of a motor between star and delta connections. This technology can improve the energy efficiency of motors at both low and high frequencies and shows promise for application in air conditioning compressors. However, to improve the cost-effectiveness of air conditioning compressors, the power density of motors is constantly increasing. With switching winding technology, the range of motor parameters becomes much larger, reducing the match between motor parameters and control parameters, leading to speed fluctuations and a decrease in actual operating efficiency. Summary of the Invention

[0003] Therefore, the present invention provides an electric motor, a compressor, and an air conditioner. The main technical problem to be solved is: how to reduce the speed fluctuation of an electric motor using the winding-cutting technology and improve the motor efficiency.

[0004] To solve the above problems, the present invention provides an electric motor, which includes a stator, a rotor and a stator winding, wherein the connection method of the stator winding can be switched between a star connection method and a delta connection method;

[0005] The stator has stator teeth evenly arranged circumferentially, and the stator winding includes coil windings wound on each stator tooth, each coil winding having N turns of coils connected in series; the motor is a three-phase motor, and the single-phase stator winding of the motor has m parallel branches. If the single-phase stator winding of the motor has no parallel branches, then m = 1.

[0006] The rotor has P poles, and the width of the magnet in a single magnetic pole of the rotor is W, the thickness of the magnet is D, and the axial height of the magnet is H.

[0007] Where 0.5≤N*N / m / m / (W*D*H*P)≤1.2, and the units of W, D and H are all millimeters.

[0008] In some embodiments, a single magnetic pole of the rotor has two or more magnets arranged sequentially, and the width W of the magnets in a single magnetic pole of the rotor is the sum of the widths of all the magnets in a single magnetic pole of the rotor.

[0009] In some embodiments, the outer diameter of the rotor is Dr, and the outer diameter of the stator is Ds; wherein 0.5≤Dr / Ds≤0.58, and the units of Dr and Ds are both millimeters.

[0010] In some embodiments, the magnets within a single magnetic pole of the rotor are arranged in a straight line, a V-shape, or in multiple layers.

[0011] In some embodiments, the magnets within the magnetic poles of the rotor are permanent magnets.

[0012] In some embodiments, the permanent magnet is a neodymium iron boron permanent magnet.

[0013] In some embodiments, the stator is a stator using a concentrated winding method.

[0014] In some implementations, P is less than or equal to 8.

[0015] The present invention also provides a compressor comprising the motor described in any one of the above-described embodiments.

[0016] The present invention also provides an air conditioner, which includes the motor described in any one of the above-mentioned methods; or includes the compressor described in the above-mentioned methods.

[0017] The electric motor, compressor, and air conditioner provided by this invention have the following beneficial effects:

[0018] This invention ensures that the motor parameters of the stator windings are within a suitable range of control parameters in both delta and star connection configurations by maintaining a value of 0.5 ≤ N*N / m / m / (W*D*H*P) ≤ 1.2, resulting in minimal motor speed fluctuations and improved motor efficiency. Furthermore, when applied to compressors, this invention enhances the actual control accuracy and efficiency of the compressor. Attached Figure Description

[0019] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0020] Figure 1 This is a cross-sectional view of an electric motor provided in one embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of a rotor with magnets arranged in multiple layers, provided by an embodiment of the present invention;

[0022] Figure 3 A graph showing the relationship between motor speed fluctuation and motor parameters is presented.

[0023] Figure 4 The graph shows the relationship between the motor speed fluctuation and motor parameters when P=6 and m=1.

[0024] The attached figures are labeled as follows:

[0025] 1. Stator; 2. Rotor; 3. Stator winding; 31. Coil winding; 4. Magnet; 5. Lead wire; 11. Stator tooth. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0028] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0029] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0030] See also Figure 1As shown, according to an embodiment of the present invention, an electric motor is provided, which includes a stator 1, a rotor 2, and a stator winding 3. The connection method of the stator winding 3 can be switched between a star connection and a delta connection, making the electric motor of the present invention a motor employing winding-splitting technology. The specific switching method of the stator winding 3 between the star connection and the delta connection is a common technique in the prior art and will not be described in detail here.

[0031] The stator 1 described above has stator teeth 11 evenly arranged circumferentially. The stator winding 3 described above includes coil windings 31 wound on each stator tooth 11. Each coil winding 31 has N turns of coil connected in series. The motor described above is a three-phase motor, and each single-phase stator winding of the motor has m parallel branches. If there are no parallel branches in the single-phase stator winding of the motor, then m = 1, and in this case, each coil winding 31 in the single-phase stator winding of the motor is connected in series. To facilitate understanding of the number of parallel branches m in each phase stator winding, the following example is given. For instance, if the single-phase stator winding 3 has 6 coil windings 31 wound on different stator teeth 11, and these 6 coil windings 31 are divided into two groups, each group having 3 coil windings 31 connected in series, and then the two groups of coil windings 31 are connected in parallel, then the number of parallel branches in this single-phase stator winding is m = 2.

[0032] The rotor 2 has P poles. The width of the magnet within a single pole of rotor 2 is W, the thickness of the magnet is D, and the axial height of the magnet is H. Wherein, 0.5 ≤ N*N / m / m / (W*D*H*P) ≤ 1.2, and the units of W, D, and H are all millimeters.

[0033] Figure 3 A graph showing the relationship between motor speed fluctuation and motor parameters is presented. For example... Figure 3 As shown, when the value of N*N / m / m / (W*D*H*P) is too small, it will cause a mismatch between the motor parameters and control when the stator winding 3 is connected in a delta configuration, resulting in large fluctuations in motor speed and low motor efficiency. Similarly, when the value of N*N / m / m / (W*D*H*P) is too large, it will cause a mismatch between the motor parameters and control when the stator winding 3 is connected in a star configuration, resulting in large fluctuations in motor speed and low motor efficiency. However, when 0.5≤N*N / m / m / (W*D*H*P)≤1.2, it can be ensured that the motor parameters of the stator winding 3 are within the suitable range of control parameters in both delta and star configurations, resulting in smaller fluctuations in motor speed and improved motor efficiency. When this motor is used in a compressor, it can improve the actual control accuracy and efficiency of the compressor.

[0034] In a specific application example, the number of poles P of the aforementioned rotor 2 can be 6, and there are no parallel branches in the single-phase stator winding 3 of the aforementioned motor, then m = 1. Figure 4The graph shows the relationship between the motor speed fluctuation and motor parameters when P=6 and m=1. Figure 4 As shown, when 0.5≤N*N / (W*D*H*6)≤1.2, it can be guaranteed that the motor parameters of stator winding 3 are within the suitable range of control parameters under both delta connection and star connection, and the speed fluctuation of the motor is within the range of 3%-6%, which makes the speed fluctuation of the motor smaller and can improve the efficiency of the motor.

[0035] In some embodiments, a single magnetic pole of rotor 2 has two or more magnets 4 arranged sequentially, and the width W of the magnets in a single magnetic pole of rotor 2 is the sum of the widths of all the magnets 4 in a single magnetic pole of rotor 2. By arranging multiple magnets 4 in a single magnetic pole of rotor 2, the magnetic properties can be improved, thereby increasing the permanent magnet flux linkage.

[0036] To ensure that the number of turns of the aforementioned coil winding 31 and the amount of magnet 4 are within the appropriate range, a suitable design for the outer diameter of the rotor 2 and the outer diameter of the stator 1 should be ensured. In some embodiments, the outer diameter of the rotor 2 is Dr, and the outer diameter of the stator 1 is Ds. Wherein, 0.5≤Dr / Ds≤0.58, and the units of Dr and Ds are both millimeters.

[0037] In some embodiments, the magnets 4 within a single magnetic pole of the aforementioned rotor 2 can be arranged in a straight line, a V-shape, or in multiple layers.

[0038] The aforementioned two adjacent stator teeth 11 form a stator slot 1. Figure 1 A structural diagram of a motor with P=6 and 9 stator slots is shown. This motor has two sets of leads 5, and the stator winding 3 can be connected in either a star or delta configuration. The magnets 4 within each pole of the rotor 2 are V-shaped; that is, each pole of the rotor 2 has two magnets 4 arranged in a V-shape, with widths W1 and W2 respectively. In this configuration, the width of the magnets within a single pole of the rotor 2 is W = W1 + W2.

[0039] Figure 2 A schematic diagram is shown of a rotor 2 in which the magnets in a single magnetic pole are arranged in two layers. Each layer of magnets in a single magnetic pole of rotor 2 has two magnets 4 arranged in a V-shape. At this time, there are a total of 4 magnets 4 in a single magnetic pole of rotor 2. The widths of the 4 magnets 4 are W1, W2, W3 and W4, respectively. The width of the magnets in a single magnetic pole of rotor 2 is W = W1 + W2 + W3 + W4.

[0040] In some embodiments, the magnets 4 within the magnetic poles of the rotor 2 can be permanent magnets. These permanent magnets can be neodymium iron boron (NdFeB) permanent magnets, etc. The material and amount of permanent magnet directly affect the motor flux linkage. NdFeB materials have high remanence and strong magnetic properties, which can increase the permanent magnet flux linkage. Simultaneously, the higher the amount of permanent magnet material used, the larger the permanent magnet flux linkage.

[0041] In some embodiments, the aforementioned stator 1 can be a stator using a centralized winding method, so that when the aforementioned motor is applied to a variable frequency air conditioning compressor, the high-efficiency operation of the variable frequency air conditioning compressor can be guaranteed.

[0042] In a specific application example, P is less than or equal to 8. Specifically, for motors where the stator winding 3 can switch between star and delta connections, a maximum operating speed is typically higher, and a motor pole number P less than or equal to 8 is preferable.

[0043] In some embodiments, the aforementioned motor can be a centralized winding permanent magnet synchronous motor. The material and amount of permanent magnet directly affect the motor's flux linkage. Neodymium iron boron (NdFeB) material has high remanence and strong magnetic properties, which can increase the permanent magnet flux linkage; this scheme preferably uses NdFeB permanent magnet material. Simultaneously, the higher the amount of permanent magnet material used, the larger the permanent magnet flux linkage. Furthermore, while the number of series turns in stator 1 affects the permanent magnet flux linkage, it has a greater impact on the motor inductance. Research has found that considering the two wiring methods for split-winding motors, the number of series turns in stator 1, the volume of the permanent magnet, and the number of motor poles need to be rationally designed. By ensuring that 0.5 ≤ N*N / m / m / (W*D*H*P) ≤ 1.2, it can be guaranteed that the motor parameters for both wiring methods are within the suitable range of control parameters, improving the actual control accuracy and efficiency of the compressor.

[0044] In some embodiments, the present invention also provides a compressor that may include the motor described above. Because the compressor uses the aforementioned motor, by ensuring that 0.5 ≤ N*N / m / m / (W*D*H*P) ≤ 1.2, it can be guaranteed that the motor parameters of the stator winding 3 are within a suitable range of control parameters in both delta and star connection configurations. This results in smaller fluctuations in motor speed, improved motor efficiency, and higher actual control accuracy and efficiency of the compressor.

[0045] In some embodiments, the present invention also provides an air conditioner, which may include the motor described above; or include the compressor described above. Because the air conditioner uses the aforementioned motor or compressor, by ensuring that 0.5 ≤ N*N / m / m / (W*D*H*P) ≤ 1.2, it can be guaranteed that the motor parameters of the stator winding 3 are within a suitable range of control parameters in both delta and star connection configurations, resulting in smaller motor speed fluctuations, improved motor efficiency, and higher actual control accuracy and efficiency of the compressor.

[0046] The technical solution of the present invention can improve the matching degree between motor parameters and control parameters, reduce speed fluctuations, improve efficiency, and solve the matching problem between motor parameters and control parameters of a split-winding air conditioning compressor.

[0047] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. An electric motor, characterized in that: It includes a stator (1), a rotor (2) and a stator winding (3), wherein the connection method of the stator winding (3) can be switched between a star connection method and a delta connection method; The stator (1) has stator teeth (11) evenly arranged in the circumferential direction, and the stator winding (3) includes coil windings (31) wound on each stator tooth (11), each coil winding (31) having N turns of coil connected in series; the motor is a three-phase motor, and the single-phase stator winding of the motor has m parallel branches. If the single-phase stator winding of the motor has no parallel branches, then m = 1; The rotor (2) has P poles, and the width of the magnet in a single magnetic pole of the rotor (2) is W, the thickness of the magnet is D, and the axial height of the magnet is H. Where 0.5≤N*N / m / m / (W*D*H*P)≤1.2, and the units of W, D and H are all millimeters.

2. The motor according to claim 1, characterized in that: The rotor (2) has two or more magnets (4) arranged in sequence in a single magnetic pole. The width W of the magnets in a single magnetic pole of the rotor (2) is the sum of the widths of all the magnets (4) in a single magnetic pole of the rotor (2).

3. The motor according to claim 1, characterized in that: The outer diameter of the rotor (2) is Dr, and the outer diameter of the stator (1) is Ds; wherein, 0.5≤Dr / Ds≤0.58, and the units of Dr and Ds are both millimeters.

4. The motor according to claim 1, characterized in that: The magnets (4) within a single magnetic pole of the rotor (2) are arranged in a straight line, a V-shape, or in multiple layers.

5. The motor according to any one of claims 1-4, characterized in that: The magnets (4) inside the magnetic poles of the rotor (2) are permanent magnets.

6. The motor according to claim 5, characterized in that: The permanent magnet is a neodymium iron boron permanent magnet.

7. The motor according to any one of claims 1-4 and 5, characterized in that: The stator (1) is a stator that uses a concentrated winding method.

8. The motor according to any one of claims 1-4 and 5, characterized in that: P is less than or equal to 8.

9. A compressor, characterized in that: The motor included in any one of claims 1-8.

10. An air conditioner, characterized in that: It includes the motor as described in any one of claims 1-8; or it includes the compressor as described in claim 9.

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