Rotor assembly and permanent magnet motor having the same

Abstract

The present invention provides a rotor assembly and a permanent magnet motor having the same. The rotor assembly includes a plurality of rotors, and each rotor includes: a rotor core, on the outer peripheral surface of which a plurality of mounting grooves are provided; a permanent magnet, embedded in the mounting grooves; wherein, the permanent magnets of two adjacent rotors are arranged in a staggered manner. By applying the technical solution of the present invention, the technical problem of low performance of the permanent magnet motor in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular, to a rotor assembly and a permanent magnet motor having the same. Background Art

[0002] Compared with ordinary induction motors, permanent magnet motors have the advantages of small size, light weight, high power density, and easy control. The high performance, high efficiency, and high reliability of permanent magnet motors enable them to be applied in various occasions, especially in the household appliance industry. With the improvement of people's living standards, household products such as air conditioners and refrigerators have become very popular. As the core component of the refrigeration device, the energy efficiency, reliability, and automation of the compressor are important indicators for achieving high efficiency, energy conservation, and safety, and the performance indicators of the compressor motor directly determine the indicators of the compressor.

[0003] Therefore, how to set the rotor assembly to improve the performance of the permanent magnet motor is a problem that those skilled in the art need to consider. Summary of the Invention

[0004] The purpose of the present invention is to provide a rotor assembly and a permanent magnet motor having the same, so as to solve the technical problem of the low performance of the permanent magnet motor in the prior art.

[0005] To achieve the above purpose, according to one aspect of the present invention, a rotor assembly is provided, including a plurality of rotors. Each rotor includes: a rotor core, on the outer peripheral surface of which a plurality of mounting grooves are provided; a permanent magnet, embedded in the mounting grooves; wherein, the permanent magnets of two adjacent rotors are arranged in a staggered manner.

[0006] Further, the rotor assembly further includes a first connecting member and a second connecting member for connecting the plurality of rotors; a plurality of mounting holes are provided on the end surface of the rotor core, and the plurality of mounting holes include a first mounting hole, a second mounting hole, and a third mounting hole. When connecting two adjacent rotors, the first connecting member sequentially passes through the first mounting hole of one rotor core and the second mounting hole of the other rotor core, and the second connecting member sequentially passes through the second mounting hole of one rotor core and the third mounting hole of the other rotor core, so that the permanent magnets of two adjacent rotors are arranged in a staggered manner.

[0007] Further, the included angle between the central axis of the mounting hole and the center line of the groove body of the mounting groove close to the mounting hole is θ2, and the included angle formed by the permanent magnets of two adjacent rotors being staggered is θ, wherein, θ < θ2 < 2θ.

[0008] Further, the plurality of mounting grooves are spaced apart on the outer peripheral surface of the rotor core, the included angle between two adjacent mounting grooves is θ1, the included angle between the first mounting hole and the second mounting hole is θ3, and / or, the included angle between the second mounting hole and the third mounting hole is θ3, wherein, θ1 = θ3 + θ.

[0009] Further, the installation groove is a dovetail groove, and the outer surface of the permanent magnet is adapted to the inner surface of the dovetail groove.

[0010] Further, the rotor core is formed by clamping a plurality of stamped steel plates.

[0011] Further, the installation hole is a riveting hole, and the first connecting member and / or the second connecting member is a rivet.

[0012] Further, the rotor assembly further includes a first balance pressing plate and a second balance pressing plate. Along the axial direction of the rotor assembly, the first balance pressing plate covers the first end of the rotor assembly, and the second balance pressing plate covers the second end of the rotor assembly to press the permanent magnet in the axial direction of the rotor assembly.

[0013] Further, the first balance pressing plate includes a first pressing plate and a first balance block. The first balance block is arranged on the first pressing plate, wherein the first pressing plate and the first balance block are integrally formed.

[0014] Further, the outer diameter of the first balance pressing plate is smaller than the outer diameter of the permanent magnet, and the outer diameter of the second balance pressing plate is smaller than the outer diameter of the permanent magnet.

[0015] According to another aspect of the present invention, a permanent magnet motor is provided, which includes a rotor assembly and a stator assembly, and the rotor assembly is the rotor assembly described above.

[0016] Applying the technical solution of the present invention, since the permanent magnets of two adjacent rotors are arranged in a staggered manner, the two adjacent rotors form an inclined pole structure, thereby effectively weakening the tooth harmonics, reducing the cogging torque and torque ripple of the motor, improving the low-speed smooth performance of the motor, and reducing the noise during the operation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0018] Figure 1 shows a schematic structural diagram of an embodiment of a rotor assembly according to the present invention;

[0019] Figure 2 shows Figure 1 the front view of the rotor assembly;

[0020] Figure 3 shows Figure 1 the exploded structural diagram of the rotor assembly;

[0021] Figure 4 shows Figure 1 the schematic structural diagram of the rotor core of the rotor assembly;

[0022] Figure 5 shows the Figure 4 front view of the rotor core;

[0023] Figure 6 shows the Figure 1 structural schematic diagram of the first balance pressing plate of the rotor assembly;

[0024] Figure 7 shows the Figure 6 front view of the first balance pressing plate;

[0025] Figure 8 shows the Figure 1 structural schematic diagram of the permanent magnet of the rotor assembly; and

[0026] Figure 9 shows the Figure 8 front view of the permanent magnet.

[0027] Among them, the above-mentioned drawings include the following reference numerals:

[0028] 10, rotor; 11, rotor core; 12, mounting hole; 121, first mounting hole; 122, second mounting hole; 123, third mounting hole; 13, mounting groove; 14, permanent magnet; 20, first connecting member; 30, second connecting member; 40, first balance pressing plate; 41, first pressing plate; 42, first balance block; 50, second balance pressing plate. Detailed implementation manners

[0029] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0030] As Figure 1 and Figure 2 shown, this embodiment provides a rotor assembly, which includes a plurality of rotors 10. The rotor 10 includes a rotor core 11 and a permanent magnet 14. A plurality of mounting grooves 13 are provided on the outer peripheral surface of the rotor core 11; the permanent magnet 14 is embedded in the mounting groove 13; among them, the permanent magnets 14 of two adjacent rotors 10 are arranged in a staggered manner.

[0031] In this embodiment, since the permanent magnets 14 of two adjacent rotors 10 are arranged in a staggered manner, an oblique pole structure is formed between two adjacent rotors 10, thereby effectively weakening the tooth harmonics, reducing the cogging torque and torque ripple of the motor, improving the low-speed smooth performance of the motor, and reducing the noise during the operation of the motor.

[0032] As Figures 2 to 5As shown, in this embodiment, the rotor assembly further includes a first connecting member 20 and a second connecting member 30 for connecting a plurality of rotors 10; a plurality of mounting holes 12 are provided on the end surface of the rotor core 11, and the plurality of mounting holes 12 include a first mounting hole 121, a second mounting hole 122, and a third mounting hole 123. When connecting two adjacent rotors 10, the first connecting member 20 sequentially passes through the first mounting hole 121 of one rotor core 11 and the second mounting hole 122 of the other rotor core 11, and the second connecting member 30 sequentially passes through the second mounting hole 122 of one rotor core 11 and the third mounting hole 123 of the other rotor core 11, so that the permanent magnets 14 of two adjacent rotors 10 are arranged in a staggered manner.

[0033] Specifically, the plurality of mounting holes 12 in this embodiment penetrate the axial direction of the rotor core 11. There are two groups of mounting holes 12 on the rotor core 11, and each group of mounting holes 12 includes a first mounting hole 121, a second mounting hole 122, and a third mounting hole 123. When connecting two adjacent rotors 10, the first connecting member 20 passes through the first mounting hole 121 of the previous rotor core 11 and the second mounting hole 122 of the next rotor core 11, and the second connecting member 30 passes through the second mounting hole 122 of the previous rotor core 11 and the third mounting hole 123 of the next rotor core 11, so as to form a misalignment angle between the permanent magnets 14 of the two connected rotors 10, realizing the setting of the skewed pole structure of the rotor assembly. The above setting method has a simple structure, simplifies the processing technology, and is easy to implement.

[0034] As Figure 5 shown, in this embodiment, the included angle between the central axis of the mounting hole 12 and the center line of the groove body of the mounting groove 13 close to the mounting hole 12 is θ2, and the included angle formed by the misalignment of the permanent magnets 14 on two adjacent rotors 10 is θ. Among them, θ < θ2 < 2θ.

[0035] Specifically, the position of the mounting hole 12 is set according to the position of the mounting groove 13. The size of θ2 is reasonably set according to the required misalignment included angle θ, so as to ensure the misalignment included angle θ of the permanent magnets 14 of two adjacent rotors 10 of the assembled rotor assembly, thereby reducing the cogging torque and torque ripple of the motor and improving the motor performance.

[0036] As Figure 4 and Figure 5 shown, in this embodiment, the plurality of mounting grooves 13 are spaced on the outer peripheral surface of the rotor core 11, the included angle between two adjacent mounting grooves 13 is θ1, the included angle between the first mounting hole 121 and the second mounting hole 122 is θ3, and the included angle between the second mounting hole 122 and the third mounting hole 123 is θ3. Among them, θ1 = θ3 + θ.

[0037] In this embodiment, when assembling two adjacent rotors 10, the first connecting member 20 is sequentially passed through the first mounting hole 121 of the previous rotor 10 and the second mounting hole 122 of the subsequent rotor 10, so that the permanent magnets 14 of the previous rotor 10 and the subsequent rotor 10 do not coincide, and are mutually displaced to form an included angle θ. In this connection mode, the previous rotor 10 rotates by an angle of θ3 relative to the subsequent rotor 10. Since the included angle between two adjacent permanent magnets 14 on the same rotor 10 is θ1, the skewed pole included angle θ formed after the adjacent two rotors 10 are misaligned and installed is θ = θ1 - θ3.

[0038] Through the above settings, when the number of stages of the rotor assembly is determined, the included angle θ3 between the first mounting hole 121 and the second mounting hole 122 can be calculated when processing the rotor core 11 according to the required skewed pole included angle θ, so as to form the skewed pole included angle θ when installing the rotor assembly to meet the requirements of the motor.

[0039] Preferably, as Figures 3 to 5 shown, in this embodiment, the installation groove 13 is a dovetail groove, and the outer surface of the permanent magnet 14 is adapted to the inner surface of the dovetail groove.

[0040] Specifically, as Figure 5 shown, an included angle α is formed between the groove body of the installation groove 13 and the rotor core 11. As Figure 8 and Figure 9 shown, an included angle α matching the installation groove 13 is provided between the side of the permanent magnet 14 facing the rotor core 11 and the side along the radial direction of the rotor.

[0041] In the motors in the prior art, the permanent magnets are usually pasted on the surface of the rotor core by an adhesive, and the reliability and stability during the high-speed operation of the motor depend on the adhesive force between the permanent magnet and the rotor core. And the operating process in the bonding production, factors such as the usage amount and quality of the adhesive will affect the bonding strength. Moreover, high-temperature baking is required after bonding, the production process is complex, and the production efficiency is low. With the long-term operation of the motor, the adhesive will age, the adhesive force will gradually weaken, and on the action line of the centrifugal force of the motor, the permanent magnet is likely to fall off, having a safety hazard of jamming the rotor and making the motor unable to operate, and is likely to cause accidents.

[0042] However, the permanent magnet 14 in this embodiment is installed through the installation groove 13. After installation, the permanent magnet 14 is embedded in the installation groove 13 of the rotor core 11. The installation is simple and has a high strength. There is no need to use an adhesive or other connection structures, which reduces the cost, improves the installation efficiency, and avoids safety hazards.

[0043] When installing the rotor assembly, the permanent magnet 14 is installed on the rotor core 11 through the installation groove 13, so that the permanent magnet 14 is embedded in the installation groove 13 of the rotor core 11 to form the rotor 10. Further, when assembling the rotor assembly, adjacent rotors 10 are connected by the first connecting member 20 and the second connecting member 30, and by selecting different installation holes 12 on the two rotors 10, the permanent magnets 14 on the adjacent two rotors 10 are made non-collinear in the central axis direction of the rotor 10, forming the skewed pole structure of the rotor assembly.

[0044] Preferably, in this embodiment, the rotor core 11 is formed by clamping a plurality of stamped steel plates.

[0045] Specifically, the rotor core 11 is formed by stamping and clamping electrical steel sheets with a thickness of 0.35 mm or 0.5 mm. The stamped steel sheets have stamped protrusions and grooves, and a plurality of steel sheets are laminated and formed through the cooperation of the protrusions and grooves. The number of the protrusions and grooves can be arranged as required.

[0046] Further, the installation hole 12 is a riveting hole, and the first connecting member 20 and the second connecting member 30 are rivets.

[0047] The above settings have a simple process, low cost, and are convenient for installation and disassembly.

[0048] As Figure 3 、 Figure 6 and Figure 7 shown, in this embodiment, the rotor assembly further includes a first balance pressing plate 40 and a second balance pressing plate 50. Along the axial direction of the rotor assembly, the first balance pressing plate 40 covers the first end of the rotor assembly, and the second balance pressing plate 50 covers the second end of the rotor assembly to press the permanent magnet 14 in the axial direction of the rotor assembly.

[0049] Through the above settings, the installation strength of the permanent magnet 14 in the axial direction of the rotor assembly is ensured, and further the stability of the rotor assembly during the use of the motor is ensured.

[0050] As Figure 6 and Figure 7 shown, in the embodiment, the first balance pressing plate 40 includes a first pressing plate 41 and a first balance block 42, and the first balance block 42 is arranged on the first pressing plate 41, wherein the first pressing plate 41 and the first balance block 42 are of an integrally formed structure.

[0051] To ensure the normal operation of the rotor assembly, it is necessary to add counterweight blocks to the rotor assembly to ensure the stability during the rotation of the rotor assembly. In the prior art, the balance blocks and the pressing plates for counterweight are separately arranged, with a large number of components and cumbersome installation, which is not convenient for assembly. In this application, the first pressing plate 41 and the first balance block 42 are integrally formed to form the first balance pressing plate 40, so as to reduce the components of the rotor assembly, simplify the assembly and installation of the rotor assembly, and the structure is more simple.

[0052] Preferably, the second balance pressing plate 50 in this embodiment includes a second pressing plate and a second balance block. The second balance block is arranged on the second pressing plate, and the second pressing plate and the second balance block are of an integrally formed structure.

[0053] Furthermore, two mounting through holes are provided on both the first balance pressing plate 40 and the second balance pressing plate 50, and the included angle between the two mounting through holes is θ3.

[0054] As Figure 1 shown, in this embodiment, the outer diameter of the first balance pressing plate 40 is smaller than the outer diameter of the permanent magnet 14, and the outer diameter of the second balance pressing plate 50 is smaller than the outer diameter of the permanent magnet 14.

[0055] Through the above settings, during the rotation of the rotor assembly, it is avoided that the outer diameters of the first balance pressing plate 40 or the second balance pressing plate 50 are too large to interfere with the stator assembly, and safety accidents are prevented. Preferably, the outer diameters of the first balance pressing plate 40 and the second balance pressing plate 50 are set larger than the outer diameter of the rotor core 11 to press the permanent magnet 14 in the axial direction of the rotor core 11 to ensure the normal operation of the rotor assembly.

[0056] This embodiment also provides a permanent magnet motor, including a rotor assembly and a stator assembly, and the rotor assembly is the above-mentioned rotor assembly.

[0057] In this embodiment, since the permanent magnets 14 of two adjacent rotors 10 are arranged in a staggered manner, an oblique pole structure is formed between two adjacent rotors 10, thereby effectively weakening the tooth harmonics, reducing the cogging torque and torque ripple of the motor, improving the low-speed stability performance of the motor, and reducing the noise during the operation of the motor. Therefore, the permanent magnet motor with the above-mentioned rotor assembly also has the above advantages.

[0058] Taking the rotor with 8 equally distributed permanent magnets as an example, the included angle θ1 between two adjacent permanent magnets 14 = 360° / 8 = 45°. If the required oblique pole included angle θ is 5°, then the included angle θ3 between two adjacent mounting holes 12 needs to be set to 40°. Since the positioning included angle θ2 of the mounting hole 12 needs to satisfy the following relationship: θ < θ2 < 2θ, when setting the mounting hole 12, the included angle θ2 between the central axis of the mounting hole 12 and the center line of the groove body of the mounting groove 13 close to the mounting hole 12 can be set between 5° and 10°.

[0059] Of course, in alternative embodiments not shown, the number of magnetic poles is not limited to 8 poles, and can be 6 poles, 10 poles, 12 poles, etc., which are set according to production needs. Only the angular value of θ1 needs to be changed accordingly.

[0060] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0061] Since the permanent magnets of two adjacent rotors are arranged in a staggered manner, an inclined pole structure is formed between two adjacent rotors, thereby effectively weakening the tooth harmonics, reducing the cogging torque and torque ripple of the motor, improving the low-speed smooth performance of the motor, and reducing the noise during the operation of the motor.

[0062] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rotor assembly, comprising a plurality of rotors (10), characterized in that, The rotor (10) includes: a rotor core (11), on the outer peripheral surface of which there are provided a plurality of mounting grooves (13); a permanent magnet (14), embedded in the mounting groove (13); wherein, the permanent magnets (14) of two adjacent rotors (10) are arranged in a staggered manner; The rotor assembly further includes a first connecting member (20) and a second connecting member (30) for connecting the plurality of rotors (10); a plurality of mounting holes (12) are provided on the end surface of the rotor core (11), and the plurality of mounting holes (12) include a first mounting hole (121), a second mounting hole (122) and a third mounting hole (123). When connecting two adjacent rotors (10), the first connecting member (20) sequentially passes through the first mounting hole (121) of one rotor core (11) and the second mounting hole (122) of the other rotor core (11), and the second connecting member (30) sequentially passes through the second mounting hole (122) of one rotor core (11) and the third mounting hole (123) of the other rotor core (11), so that the permanent magnets (14) of two adjacent rotors (10) are arranged in a staggered manner; The included angle between the central axis of the mounting hole (12) and the center line of the groove body of the mounting groove (13) close to the mounting hole (12) is θ2, and the included angle formed by the staggering of the permanent magnets (14) on two adjacent rotors (10) is θ, wherein, θ < θ2 < 2θ; The plurality of mounting grooves (13) are arranged at intervals on the outer peripheral surface of the rotor core (11), the included angle between two adjacent mounting grooves (13) is θ1, the included angle between the first mounting hole (121) and the second mounting hole (122) is θ3, and / or the included angle between the second mounting hole (122) and the third mounting hole (123) is θ3, wherein, θ1 = θ3 + θ; The rotor core (11) is formed by clamping a plurality of stamped steel plates.

2. The rotor assembly according to claim 1, wherein The mounting groove (13) is a dovetail groove, and the outer surface of the permanent magnet (14) is adapted to the inner surface of the dovetail groove.

3. The rotor assembly according to claim 1, characterized in that, The mounting hole (12) is a riveting hole, and the first connecting member (20) and / or the second connecting member (30) is a rivet.

4. The rotor assembly according to claim 1, wherein The rotor assembly further includes a first balance pressing plate (40) and a second balance pressing plate (50). Along the axial direction of the rotor assembly, the first balance pressing plate (40) covers the first end of the rotor assembly, and the second balance pressing plate (50) covers the second end of the rotor assembly to press the permanent magnet (14) in the axial direction of the rotor assembly.

5. The rotor assembly according to claim 4, wherein The first balance pressing plate (40) includes a first pressing plate (41) and a first balance block (42), and the first balance block (42) is arranged on the first pressing plate (41), wherein, the first pressing plate (41) and the first balance block (42) are of an integrally formed structure.

6. The rotor assembly according to claim 4, wherein, The outer diameter of the first balancing pressing plate (40) is smaller than the outer diameter of the permanent magnet (14), and the outer diameter of the second balancing pressing plate (50) is smaller than the outer diameter of the permanent magnet (14).

7. A permanent magnet motor, comprising a rotor assembly and a stator assembly, characterized in that, The rotor assembly is the rotor assembly according to any one of claims 1 to 6.

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