A motor rotor, a gap piece assembly, a motor, a compressor and a refrigerator

Abstract

A motor rotor, a gap piece assembly, a motor, a compressor and a refrigerator, relate to the technical field of refrigerator, the motor rotor includes rotor core and permanent magnet, the rotor core includes function section, the function section is located at one end of the rotor core away from the permanent magnet, the function section is provided with n matching grooves on the radial periphery, n >= 2, the motor rotor can increase the fixing force arm of the fixing tool under the condition of reducing the rotor volume, and also can increase the diameter of the fixing part of the fixing tool, so as to improve the safety and reliability of the magnetizing fixing tool of the rotor production line, the motor rotor is matched with the gap piece assembly, the gap piece can be accurately positioned with the rotor, and the position of the gap piece in the stator-rotor gap can be conveniently adjusted, so that the gap piece is accurately located between the inner arc of the stator and the outer arc of the rotor, and the assembly efficiency and assembly quality of the stator-rotor of the refrigeration compressor production line are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of refrigerator technology, and in particular to motor rotors, spacer assemblies used in conjunction with motor rotors, motors, compressors, and refrigerators. Background Technology

[0002] With the miniaturization of refrigerator compressors, the size of the compressors is getting smaller, and correspondingly, the size and volume of the compressor motors are also decreasing. However, since the operating conditions and quality requirements of the compressors have not decreased, the reduction in motor size has also brought about many problems.

[0003] In the actual production process of compressor motor rotors, non-magnetic permanent magnets are generally assembled onto the rotor core to form a rotor assembly, which is then fixed to the compressor crankshaft via the shaft holes of the rotor assembly. The rotor assembly, assembled on the compressor cylinder block and crankshaft, is placed in a magnetizing device and fixed in place. The common fixing method involves several tooling fixtures engaging with the magnetizing holes on the rotor core to maintain the relative position of the permanent magnets in the rotor assembly to the magnetizing coil in the magnetizing device. A large instantaneous current is passed through the magnetizing coil to generate a suitable magnetic field, thus magnetizing the permanent magnets in the rotor assembly, producing the required magnetism. Because this magnetization process is extremely short, the strong magnetic field generated by the magnetizing coil creates significant resistance along the entire flow path, resulting in a large torque on the rotor assembly. This torque primarily acts on the tooling fixtures of the rotor assembly. As the size and volume of the rotor decrease, on the one hand, under the same magnetizing torque, the force arm of the tooling fixing part decreases, resulting in a significant increase in the force it experiences. At the same time, there is not enough space to increase the structural strength by increasing the diameter of the fixing part, thus creating a risk of breakage of the fixing fixture. On the other hand, with the drastic reduction in the size and volume of the rotor, there is almost no space to make magnetizing positioning holes except for rivet holes and iron core fastening points, which makes the production and manufacturing of the compressor difficult.

[0004] During the assembly of the compressor's stator and rotor, the air gap width between the motor's stator and rotor needs to be controlled using stator-rotor gap shims to ensure uniformity and a reasonable design. By temporarily filling the air gap with gap shims of similar thickness to the stator-rotor air gap width, the relative positions of the stator and rotor can be positioned appropriately. After the stator is installed and fixed, removing the gap shims ensures that the air gap is uniform and meets requirements. The aforementioned stator-rotor air gap refers to the space between the inner arc of the stator and the outer arc of the rotor during assembly. The assembly of the stator and rotor aims to ensure that the air gap width between these two arcs is uniform and within the reasonable range of the design value. During stator-rotor assembly, it is crucial to ensure that the gap shims are accurately positioned between the inner arc of the stator and the outer arc of the rotor to effectively control the air gap width. However, the stator structure is generally designed with a certain number of teeth on the inner side, which divides the inner arc of the stator into multiple arc segments. Especially when the stator tooth structure has tangential edges, the inner arc segments of the stator will be even narrower. The outer circle of the permanent magnet surface-mount rotor is also divided into multiple arc segments due to the tangential structure of the permanent magnet. The current stator and rotor structure and the spacer structure cannot ensure that the spacer is simultaneously positioned between the inner arc of the stator and the outer arc of the rotor during the assembly of the motor stator and rotor to achieve the purpose of controlling the gap width. There is no mutual positioning and adjustment space among the three, which greatly affects the assembly efficiency of the motor stator and rotor. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings of the prior art by providing a motor rotor mechanism for a compressor, which can achieve the beneficial effects of improving the safety and reliability of the magnetization and fixing fixtures in the rotor production line, and improving the assembly efficiency and quality of the stator and rotor in the refrigeration compressor production line.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] An electric motor rotor includes a rotor core and a permanent magnet. The rotor core includes a functional segment located at the end of the rotor core furthest from the permanent magnet. The functional segment has n mating slots (n ≥ 2) on its radial outer periphery. These slots engage with a fixing part of a magnetizing fixture, thus fixing the rotor structure during magnetization. Because the mating slots are located on the radial outer periphery of the functional segment of the motor rotor, the lever arm of the fixing part of the magnetizing fixture is maximized, thereby improving the reliability of the fixing part.

[0008] In one specific embodiment of the present invention, the projection of the mating groove along the axial direction is a semi-circle or a semi-polygon. Setting the mating groove to have a semi-circle or semi-polygon projection along the axial direction is beneficial for mating with the fixing part of the magnetizing tool.

[0009] In a specific embodiment of the present invention, the radial outer periphery of the functional segment is a polygon or a circle with the same shape along the axial direction; when the radial outer periphery of the functional segment is a polygon with the same shape along the axial direction, the polygon is preferably a regular polygon or a combination of regular polygons; the mating grooves are evenly distributed on the radial outer periphery of the functional segment, that is, when the radial outer periphery of the functional segment is a circle with the same shape along the axial direction, the mating grooves are evenly distributed on the radial outer periphery of the circle. Further, when the radial outer periphery of the functional segment is a polygon with the same shape along the axial direction, the mating groove is located at the middle position of the edge of the polygon. Setting the mating grooves and the radial outer periphery of the functional segment as described above makes the force on the functional segment and the fixing part of the magnetizing fixture more uniform, further improving the reliability during the magnetization process.

[0010] As a specific embodiment of the present invention: n = 3 or n = 4. The number of mating grooves can be selected according to actual needs, but too many mating grooves are difficult to assemble and can be understood to easily cause a decrease in the rigidity of the outer edge of the functional section. Therefore, the number of mating grooves can be selected as 3 or 4.

[0011] As a specific embodiment of the present invention, the polygon or regular polygon or combination of regular polygons has 2p sides, where p is the number of poles of the motor.

[0012] In a specific embodiment of the present invention, the motor rotor includes a permanent magnet fixing section. The permanent magnet is disposed on the radial outer periphery of the permanent magnet fixing section. When the radial outer periphery of the functional sections is a polygon with the same shape along the axial direction, the diameter of the circumcircle of the polygon is greater than or equal to the outer diameter of the permanent magnet fixing section. When the radial outer periphery of the functional sections is a circle with the same shape along the axial direction, the diameter of the circle is greater than or equal to the outer diameter of the permanent magnet fixing section. Setting the above dimensions can further increase the lever arm of the magnetizing fixture fixing part and further improve the reliability of the magnetizing fixture fixing part.

[0013] As a specific embodiment of the present invention, the mating groove can also be used to mate with the rotor core mating part of the spacer assembly, so that the spacer of the spacer assembly is located in the outer arc region of the permanent magnet and the relative position remains unchanged. The mating groove can also be used to mate with the spacer assembly, so that the spacer is opposite to the outer arc region of the permanent magnet and the relative position of the two remains unchanged, making the position of the spacer within the stator-rotor gap controllable, and ensuring that the spacer is aligned with the outer arc region of the permanent magnet and the inner arc region of the stator at its maximum amplitude, thereby improving the assembly quality and efficiency of the stator and rotor.

[0014] The present invention also provides a spacer assembly for use in conjunction with the motor rotor during the assembly of the motor rotor and stator described above;

[0015] The spacer assembly includes a spacer and a rotor core mating part, wherein the spacer is configured to conform to the shape of the outer arc region of the permanent magnet.

[0016] The rotor core mating part is used to mate with and position itself in the mating slot provided on the functional section, so that the spacer portion fits into the outer arc area of ​​the permanent magnet and the relative position remains unchanged.

[0017] In one specific embodiment of the present invention, the number of spacers is the same as the number of rotor poles of the motor rotor. Setting the same number of spacers as the number of rotor poles allows for better control of the gap between the stator and rotor during assembly, thus improving assembly quality.

[0018] The present invention also discloses an electric motor comprising the electric motor rotor described above. The present invention further discloses a compressor comprising the electric motor described above. The present invention also discloses a refrigerator comprising the above-described compressor.

[0019] The motor rotor, spacer assembly, motor, and compressor of the present invention have the following technical effects:

[0020] The motor rotor provided by this invention can increase the fixing arm of the fixing fixture while reducing the rotor volume, and can also increase the diameter of the fixing part of the fixing fixture, thereby improving the safety and reliability of the magnetization fixing fixture in the rotor production line.

[0021] The motor rotor provided by this invention is equipped with a matching gap plate assembly, which enables the gap plate to be accurately positioned relative to the rotor. At the same time, the position of the gap plate within the stator-rotor gap can be easily adjusted, ensuring that the gap plate is accurately located between the inner arc of the stator and the outer arc of the rotor, which greatly improves the assembly efficiency and assembly quality of the stator and rotor in the refrigeration compressor production line.

[0022] The motor rotor provided by this invention can also serve to assemble and fix the compressor oil pump, thereby providing more space for optimizing the compressor crankshaft structure and length. Attached Figure Description

[0023] The invention will be further illustrated with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the invention. For those skilled in the art, other drawings can be obtained based on the following drawings without any creative effort.

[0024] Figure 1 This is a schematic diagram of the original motor rotor.

[0025] Figure 2 This is a schematic diagram of an explosion of a motor rotor according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the motor rotor and the magnetizing fixture in one embodiment of the present invention.

[0027] Figure 4This is a schematic diagram showing the relative positions of the arc areas during the assembly of the stator and rotor of a motor in the existing technology.

[0028] Figure 5 This is a schematic diagram of the assembly of the motor rotor and the spacer assembly of the present invention.

[0029] Figure 6 This is a schematic diagram showing the relative positions of the stator, rotor, and spacer plate during motor installation according to an embodiment of the present invention.

[0030] Figure 7 These are schematic diagrams of the radial outer periphery of the functional segment and the mating groove in two specific embodiments of the present invention.

[0031] Figure 8 This is a schematic diagram of the radial outer periphery of a functional segment in a specific embodiment of the present invention.

[0032] The attached figures are numbered as follows:

[0033] 11. Rotor core; 12. Permanent magnet; 111. Magnetizing fixture fixing hole; 2. Motor rotor; 21. Rotor core; 22. Permanent magnet; 211. Functional section; 212. Shaft hole section; 213. Countersunk hole section; 2111. Mating groove; 25. Outer arc area of ​​permanent magnet; 31. Magnetizing coil; 32. Stator tooth arc area; 2-3. Common arc area; 4. Magnetizing fixture; 41. Magnetizing fixture fixing part; 5. Spacer assembly; 51. Spacer; 52. Rotor core mating part. Detailed Implementation

[0034] The present invention will be further described in conjunction with the following embodiments.

[0035] This invention provides a motor rotor for a refrigeration compressor used in refrigerators. The rotor structure provided by this invention addresses the problem of reduced reliability of rotor magnetization and fixing fixtures on production lines caused by the decreasing outer diameter of the rotor due to the miniaturization strategy adopted in current refrigerator compressors, which leads to a reduction in the overall size of the motor stator. Furthermore, the rotor structure provided by this invention can significantly improve the production efficiency and assembly quality of stator and rotor assembly on the compressor production line.

[0036] like Figure 1The image shows the original motor rotor, which includes a rotor core 11 and a permanent magnet 12. Several magnetizing fixture fixing holes 111 are formed on the rotor core. On the compressor production line, the rotor core is fitted onto the crankshaft of the compressor assembly through shaft holes. The fixing part of the magnetizing fixture cooperates with the fixing holes on the rotor core to complete the positioning and fixing of the rotor assembly. A strong magnetic field is generated instantaneously by energizing the magnetizing equipment, placing the permanent magnet in the strong magnetic field and thus completing the magnetization. During this magnetization process, the rotor assembly experiences a large torque, which is converted into a force applied to the fixing part of the magnetizing fixture. Because the existing rotor assembly has a relatively large outer diameter, the distance between the fixing part of the magnetizing fixture and the rotor's central rotation axis is relatively large, meaning the lever arm of the fixing part of the magnetizing fixture is long. Therefore, the force acting on the fixing part of the magnetizing fixture is within a controllable range. However, with the trend of miniaturization in refrigeration compressors, the rotor size of compressor motors is also continuously decreasing along with the stator's external dimensions. This results in a significant reduction in the distance between the fixing hole of the magnetizing fixture on the rotor core and the rotor's central rotation axis, which in turn significantly increases the force acting on the fixing part of the magnetizing fixture during the magnetization process. Simultaneously, there is insufficient space on the rotor core to increase the size of this fixing hole to match the increased diameter of the fixing part of the magnetizing fixture and improve its strength. This leads to a potential risk of a significant decrease in the reliability of the magnetizing fixture during the magnetization process.

[0037] like Figure 2 The image shows a refrigeration compressor motor rotor 2 provided by the present invention. The rotor core 21 of the motor rotor 2 includes a countersunk section 213, a shaft hole section 212, and a functional section 211. The countersunk section 213 and the shaft hole section 212 are axially stacked to form a permanent magnet fixing section, and the permanent magnet 22 is attached to the outer side of this section of the rotor core. Several mating grooves 2111 are provided on the radial outer circumference of the functional section 211 of the rotor core. These mating grooves 2111 are used to cooperate with the magnetizing fixture fixing part 41, and play a role in fixing the rotor structure when the permanent magnet 22 is magnetized. At the same time, because its position is located on the outer circumference of the rotor structure, it maximizes the force arm of the magnetizing fixture fixing part, thereby improving the reliability of the magnetizing fixture fixing part. Simultaneously, the mating groove 2111 is also used to mate with the gap plate assembly 5, so that the gap plate is opposite to the outer arc region of the permanent magnet, and the relative position of the two remains unchanged. This makes the position of the gap plate within the stator-rotor gap controllable, and ensures that the gap plate is aligned with both the outer arc region of the permanent magnet and the inner arc region of the stator at its maximum amplitude. This improves the assembly quality and efficiency of the stator and rotor. The specific structure of the gap plate assembly is as follows: Figure 5 As shown.

[0038] In this embodiment, the countersunk rotor core section has a circular radial outer circumference with a diameter of Φ1 and a circular inner hole with a diameter of Φ′1, and the two circles are coaxial. The rotor core shaft hole section has a circular radial outer circumference with a diameter of Φ1 and a circular inner hole with a diameter of Φ″1, and the two circles are coaxial. The countersunk rotor core section and the rotor core shaft hole section are coaxially superimposed to form a permanent magnet fixing section. The permanent magnet is glued to the radial outer circumference of the rotor core in the permanent magnet fixing section. After gluing, the combined outer diameter of the permanent magnet and the rotor core in the permanent magnet fixing section is Φ0. The rotor core functional section has a non-complete polygonal radial outer circumference with a circumscribed circle diameter of Φ2 and a circular inner hole with a diameter of Φ′2, and the two circles are coaxial. The radial outer circumference of the rotor core functional section has three arc-shaped fitting grooves. In this embodiment, the diameters of the motor rotor satisfy the following relationship: Φ0≥Φ2≥Φ1>Φ′1>Φ′2≥Φ″1.

[0039] like Figure 3 The diagram shows the mutual positioning and fixing of the rotor assembly and magnetizing fixture provided by this invention. As shown, when the rotor is six-pole, there are six magnetizing coils 31 opposite the permanent magnet 22. A large instantaneous current is passed through the coil 31 to generate a strong magnetic field, causing the permanent magnet to become magnetic. The instantaneous strong magnetic field forms a magnetic field loop in the rotor structure, generating a strong torque on the motor rotor 2. This torque will generate a large impact force on the rotor magnetizing fixing part. If the impact force is too large or the fixing part is not strong enough, there will be a significant safety hazard. The rotor structure provided by this invention transfers the mating structure between the rotor core and the magnetizing fixing part 41 to the radial outer periphery of the functional section and optimizes it into a non-closed shape. This structure can increase the lever arm of the magnetizing fixing part while reducing the rotor size, and can also increase the diameter of the magnetizing fixing part itself as needed, thereby significantly improving the safety and reliability of the magnetizing fixture.

[0040] like Figure 4 The diagram shows the relative positions of the stator and rotor of a refrigerator compressor motor during assembly. As shown, when the stator and rotor are in a certain relative position, the center of a permanent magnet outer arc region 25 on the rotor is directly opposite the center of a tooth arc region 32 on the stator. The common arc region 2-3 of these two is the stator tooth arc region. However, the common arc region 2-3 between the other rotor arc regions and the stator arc regions is extremely small. In this state, it is practically impossible to use a spacer to ensure uniform spacing between the stator and rotor. Furthermore, because the spacer cannot maintain a relative position with either the stator or rotor in this situation, all three are in a movable state, making it very easy for the spacer to be positioned at the cut edge of the stator and rotor, leading to functional failure.

[0041] like Figure 5The diagram illustrates the use of a spacer assembly 5 for stator-rotor gap control during the assembly of the motor rotor and stator, as provided by this invention. As shown, the number of spacers 51, matching the number of poles of the motor rotor, is designed and fixedly mounted on the spacer assembly 5. Simultaneously, since the spacer assembly 5 has a rotor core mating part 52 that cooperates with the functional section of the rotor assembly, the two are mutually positioned, allowing the spacers 51 to coincide with the outer arc region of the permanent magnet and maintain a constant relative position. This coincidence means that a portion of the spacer is positioned to fit against the outer arc of the permanent magnet. By adjusting the spacer assembly 5, the position of the spacers 51 in the stator-rotor gap can be adjusted, while the relative position of the outer arc region of the permanent magnet and the spacers 51 remains unchanged. Through the cooperation of the spacer assembly 5 and the rotor structure, the position of the spacers 51 in the stator-rotor gap can be quickly adjusted, and the air gap uniformity during stator-rotor assembly can be improved.

[0042] like Figure 6 The diagram shows the relative positions of the stator, rotor, and spacer plates when the rotor structure provided by this invention is assembled with the stator. As shown in the figure, each spacer plate 51 is directly opposite the outer arc region of the permanent magnet and the relative position remains unchanged. By adjusting the spacer plate assembly 5, the spacer plate 51 can be placed in a suitable position so that the common arc region of the stator tooth arc region and the rotor arc region directly opposite the spacer plate 51 is maximized, thereby achieving the purpose of ensuring good air gap quality during stator and rotor assembly.

[0043] like Figure 7 As shown, the rotor functional section provided by the present invention has a radial outer periphery that is a polygon with the same axial direction. Optionally, the polygonal structure can be a regular polygon or a non-regular polygon. Preferably, the polygonal structure is a regular polygon or a combination of regular polygons, and the number of sides of the polygon is 2p, where p is the number of poles of the permanent magnet synchronous motor. Example 1 of the mating groove shape is shown on the left side of the figure. The mating groove is a semi-circle projected along the axial direction, and the center of the circle containing the semi-circle is located at the center of one side of the polygon. Example 2 of the mating groove shape is shown on the right side of the figure. The mating groove is a mating groove with a half-hexagonal shape outline, and the center of the hexagon is also located at the center of one side of the polygon. Optionally, the mating groove provided by the present invention can also be other similar shapes. Optionally, the number of mating grooves in the rotor functional section provided by the present invention is 3 or 4.

[0044] like Figure 8The diagram illustrates a specific embodiment of the present invention, where the radial outer periphery of the functional segment is a combination of regular polygons with the same axial direction. The diagram shows a twelve-sided polygon formed by the alternating combination of two regular hexagons with different circumcircle radii. Similarly, other combinations of regular polygons are also within the scope of this description, such as regular polygons with the same or different number of sides, regular polygons with the same or different circumcircle radii, and combinations that are alternating at different angles. A preferred embodiment is the symmetrical polygonal structure formed by alternating polygons as shown in the example.

[0045] In summary, the motor rotor provided by this invention solves the problem that the small size of the motor rotor used in refrigeration compressors leads to an excessively small fixing arm and excessive force in the fixing fixture for rotor magnetization, resulting in a significant reduction in the safety and reliability of the fixing fixture during rotor magnetization on the production line. It achieves the technical effect of increasing the fixing arm of the fixing fixture while reducing the rotor size, and also increasing the diameter of the fixing part of the fixing fixture, thereby improving the safety and reliability of the fixing fixture for rotor magnetization on the production line.

[0046] The motor rotor-matching gap plate assembly of this invention solves the problem that, because neither the inner contour circle of the stator nor the radial outer circumference of the rotor are complete circles, the gap plates used to control the air gap width during stator-rotor assembly cannot guarantee simultaneous alignment with the inner arc of the stator and the outer arc of the rotor, and there is no mutual positioning and adjustment space among the three, resulting in insufficient air gap width during stator-rotor assembly and low stator-rotor assembly efficiency on the production line. The rotor structure provided by this invention, supplemented by a matching gap plate assembly, allows the gap plates to be accurately positioned with the rotor, and also allows for convenient adjustment of the gap plate's position within the stator-rotor gap, ensuring that the gap plate is accurately located between the inner arc of the stator and the outer arc of the permanent magnet, greatly improving the assembly efficiency and quality of stator and rotor in refrigeration compressor production lines.

[0047] In existing compressor structures, the oil pump is typically fitted onto the outer diameter of the shaft extending from the rotor shaft bore via an interference fit. With this rotor structure, the oil pump can be fitted into the inner bore of the functional section via an interference fit, eliminating the need to lengthen the shaft to accommodate both the functional section and the oil pump. In this invention, the shaft length can even be shortened to meet structural and application requirements, thus saving crankshaft material.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A motor rotor, characterized in that: The motor rotor includes a rotor core and a permanent magnet. The rotor core includes a functional section located at the end of the rotor core away from the permanent magnet. The functional section has n matching slots on its radial outer periphery, where n≥2. The radial outer periphery of the functional segment is the same polygon or the same circle along the axial direction; When the radial outer periphery of the functional segment is a polygon with the same shape along the axial direction, the number of sides of the polygon is 2p, where p is the number of poles of the motor; The motor rotor includes a permanent magnet fixing section. The permanent magnet is disposed on the radial outer periphery of the permanent magnet fixing section. When the radial outer periphery of the functional section is a polygon with the same shape along the axial direction, the diameter of the circumcircle of the polygon is greater than or equal to the outer diameter of the permanent magnet fixing section. When the radial outer periphery of the functional section is a circle with the same shape along the axial direction, the diameter of the circle is greater than or equal to the outer diameter of the permanent magnet fixing section. The projection of the mating groove along the axial direction is a semicircle or a semi-polygon.

2. The motor rotor according to claim 1, characterized in that: When the radial outer periphery of the functional segment is the same polygon along the axial direction, the polygon is a regular polygon or a combination of regular polygons.

3. The motor rotor according to claim 1, characterized in that: The mating grooves are evenly distributed on the radial outer periphery of the functional section.

4. A motor rotor according to claim 3, characterized in that: When the radial outer periphery of the functional segment is a polygon with the same shape along the axial direction, the mating groove is located at the middle position of the edge of the polygon.

5. A motor rotor according to claim 1, characterized in that: The n=3 or n=4.

6. A spacer assembly for use in conjunction with the motor rotor during assembly with the stator according to any one of claims 1-5; The spacer assembly includes a spacer and a rotor core mating part, wherein the spacer is configured to conform to the shape of the outer arc region of the permanent magnet. The rotor core mating part is used to mate with and position itself in the mating slot provided on the functional section, so that the spacer portion fits into the outer arc area of ​​the permanent magnet and the relative position remains unchanged.

7. A spacer assembly according to claim 6, characterized in that: The number of the gap plates is the same as the number of rotor poles of the motor rotor, and each gap plate is aligned with the outer arc region of the permanent magnet body when the motor rotor is assembled with the stator.

8. An electric motor, characterized in that, The motor rotor includes any one of claims 1-5.

9. A compressor, characterized in that: Includes the motor as described in claim 8.

10. A refrigerator, characterized in that: Includes the compressor described in claim 9.

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