Rotor, motor, compressor and electric appliance

Abstract

The utility model provides a rotor, a motor, a compressor and an electric appliance, and belongs to the technical field of motors. The rotor provided by the utility model comprises a main body and a protective sleeve arranged outside the main body, wherein the protective sleeve comprises at least two protective layers which are sequentially arranged from inside to outside; all the protective layers are made of alloy materials, and the adjacent protective layers as well as the protective layers and the main body are sleeved and in interference fit; and the yield strength of the protective layer is gradually increased from inside to outside. The motor comprises the rotor. The compressor comprises the motor. The electric appliance comprises the compressor. According to the layered alloy protective sleeve provided by the utility model, the manufacturing difficulty can be reduced on the premise that the problems of eddy current loss and stress are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and in particular to a surface-mounted rotor, a motor, a compressor and an electrical appliance. Background Art

[0002] High-speed motors have the advantages of small size, high power density and high efficiency, so they have always been the focus of attention in the electrical engineering field at home and abroad. Surface-mounted rotors are often used in the field of high-speed motors due to their simple structure and easy assembly. High-speed motor rotors will generate very large centrifugal forces when running at high speeds. Because the tensile strength of permanent magnets is low, it is usually necessary to add a protective cover around the permanent magnets.

[0003] There is an existing protective cover comprising an inner layer, a middle layer and an outer layer. The inner layer and the outer layer are both made of alloy steel material or glass fiber material, and the middle layer is made of carbon fiber material. The thinner inner layer and the outer layer solve the problem of large eddy current loss and subsequent demagnetization due to heating in the previous single-layer thick alloy protective cover; the middle layer provides a larger radial elastic modulus to solve the radial stress, and the outer layer also solves the problem of axial tensile stress.

[0004] Although the existing three-layer protective cover of this type of rotor solves the eddy current loss and stress problems, the fiber material layer needs to be wound and fixed, which makes manufacturing difficult. Especially when all three layers are made of fiber material, the material needs to be wound layer by layer, which is time-consuming and labor-intensive. Utility Model Content

[0005] The first object of the utility model is to provide a rotor with reduced manufacturing difficulty under the premise of solving the eddy current loss and stress problems.

[0006] The second object of the utility model is to provide a motor with reduced manufacturing difficulty under the premise of solving the eddy current loss and stress problems.

[0007] The third object of the utility model is to provide a compressor that reduces the manufacturing difficulty while ensuring that the eddy current loss and stress problems are solved.

[0008] A fourth object of the utility model is to provide an electrical appliance that reduces manufacturing difficulty while ensuring that eddy current loss and stress problems are solved.

[0009] The first purpose of the utility model provides a rotor including a main body and a protective cover arranged outside the main body, the protective cover including at least two protective layers arranged in sequence from the inside to the outside; all protective layers are made of alloy materials, and adjacent protective layers and between the protective layers and the main body are all sleeved and interference fit; from the inside to the outside, the yield strength of multiple protective layers gradually increases.

[0010] It can be seen from the above scheme that, compared with the background technology, the protective cover of the utility model also adopts a layered design, but the difference is that each protective layer of the utility model is made of alloy material, so that the multiple protective layers and the inner protective layer and the main body can be quickly installed by heating the sleeve. Compared with the fiber material winding manufacturing, the manufacturing difficulty of the utility model is greatly reduced. Among them, the multi-layer protective layer realizes the radial segmentation of the protective cover, so that the circuit of the eddy current loss generated by the metal protective cover is blocked and separated in the radial direction, effectively reducing the total eddy current loss of the protective cover under unit thickness, further reducing the overall eddy current loss of the rotor, and also reducing the temperature rise of the rotor, reducing the risk of high-temperature demagnetization of the rotor permanent magnet. Among them, the design of increasing the yield strength of multiple alloy material protective layers from the inside to the outside can greatly reduce the stress span of the protective cover, the reduction of the stress span of the protective cover, and the reduction of the stress difference between the inner side and the outer side of the protective cover, so that the stress of the protective cover itself is more uniform, which greatly improves the utilization rate, reliability and service life of the protective cover.

[0011] A further solution is that the protective cover has two protective layers, the yield strength of the outer protective layer is greater than or equal to 1200Mpa, and the yield strength of the inner protective layer is greater than or equal to 900Mpa; or, the protective cover has three protective layers, the yield strength of the outer protective layer is greater than or equal to 1200Mpa, the yield strength of the middle protective layer is greater than or equal to 800Mpa, and the yield strength of the inner protective layer is greater than or equal to 400Mpa.

[0012] It can be seen from the above that, on the basis of increasing the yield strength of multiple alloy material protective layers from the inside to the outside, a more reasonable range of the yield strength of each protective layer is further selected, which is further conducive to reducing the stress span between the inner and outer sides of the protective cover.

[0013] Another further solution is that the hardness of the multiple protective layers is 55HRC or above.

[0014] As can be seen from the above, this setting is to ensure the strength of the protective layer itself.

[0015] A further solution is that the protective sleeve has two protective layers, the interference fit of the two protective layers is between 0.15 mm and 0.25 mm, and the interference fit between the inner protective layer and the main body is between 0.2 mm and 0.35 mm.

[0016] As can be seen from the above, selecting appropriate interference fits between the protective layers and between the protective layers and the main body according to the strength of the respective materials can ensure the reliability of the rotor as a whole.

[0017] Another further solution is that the outer diameter of the protective sleeve is greater than or equal to 20 mm and less than or equal to 100 mm.

[0018] Another further solution is that the protective cover has two protective layers, and the ratio of the thickness of the inner protective layer to the thickness of the outer protective layer is 1:1.8; or, the protective cover has three protective layers, and the ratio of the thickness of the inner protective layer, the thickness of the middle protective layer and the thickness of the outer protective layer is: 1:1.5:2.9.

[0019] It can be seen from the above that under this setting, the stress span of the protective sleeve can be reduced by 80%~90%, and the rotor eddy current loss can be reduced by 2.5%~3.8%.

[0020] Another further solution is that the protective cover has two protective layers, the inner protective layer is made of titanium alloy material, and the outer protective layer is made of alloy steel material; or, the protective cover has two protective layers, the inner protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material; or, the protective cover has three protective layers, the inner protective layer is made of aluminum alloy material, the middle protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material; or, the protective cover has three protective layers, the inner protective layer is made of magnesium alloy material, the middle protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material.

[0021] In another further solution, the main body includes a permanent magnet and two shaft end pieces respectively arranged on both sides of the permanent magnet in an axial direction, and the protective sleeve is interference fit with the shaft end pieces.

[0022] It can be seen from the above that the protective layer and the shaft end piece are connected by interference fit, and the shaft end piece is in close contact with the end face of the permanent magnet. In this way, the stability of the protective sleeve can be improved while ensuring that the protective sleeve achieves the protective effect, thereby improving the reliability of the overall rotor structure.

[0023] The second object of the present invention is to provide a motor comprising the above-mentioned rotor.

[0024] The third object of the present invention is to provide a compressor comprising the above-mentioned motor.

[0025] The fourth object of the present invention is to provide an electrical appliance comprising the above-mentioned compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a radial cross-section of the first embodiment of the rotor of the utility model.

[0027] Figure 2 It is a schematic diagram of an axial cross-section of the first embodiment of the rotor of the utility model.

[0028] Figure 3 It is a schematic diagram of a radial cross-section of a second embodiment of a rotor of the present utility model.

[0029] Figure 4It is a schematic diagram of an axial cross-section of the second embodiment of the rotor of the utility model.

[0030] Figure 5 This is a stress cloud diagram of the inner protective layer of the rotor in the first embodiment of the utility model.

[0031] Figure 6 This is a stress cloud diagram of the middle protective layer in the first embodiment of the rotor of the utility model.

[0032] Figure 7 This is a stress cloud diagram of the outer protective layer of the rotor in the first embodiment of the utility model.

[0033] Figure 8 This is a stress cloud diagram of the inner protective layer of the second embodiment of the rotor of the utility model.

[0034] Fig. 9 This is a stress cloud diagram of the outer protective layer of the second embodiment of the rotor of the utility model.

[0035] Fig.10 This is the stress cloud diagram of the existing single-layer protective cover.

[0036] Fig.11 This is a bar graph comparing the eddy current losses of the first embodiment, the second embodiment of the rotor of the utility model and the single-layer protective sleeve rotor. DETAILED DESCRIPTION

[0037] Rotor First Embodiment

[0038] The electrical appliance for which protection is sought in the present utility model comprises a compressor, the compressor comprises a motor, and the motor comprises the rotor of the present embodiment.

[0039] See also Figure 1 The rotor includes a main body 1 and a protective sleeve 2 mounted outside the main body 1, wherein the main body 1 includes a permanent magnet 11 and two shaft end pieces 12 respectively arranged on both sides of the axial direction of the permanent magnet 11, the permanent magnet 11 and the shaft end pieces 12 are in close contact and fit, and the protective sleeve 2 is in interference fit with the two shaft end pieces 12.

[0040] In this embodiment, the protective cover 2 includes three protective layers arranged in sequence from the inside to the outside: an inner protective layer 21, a middle protective layer 22 and an outer protective layer 23. The inner protective layer 21 is the inner protective layer of the utility model, the middle protective layer 22 is the middle protective layer of the utility model, and the outer protective layer 23 is the outer protective layer of the utility model.

[0041] In this embodiment, the protective layer 21, the middle protective layer 22 and the outer protective layer 23 are made of aluminum alloy material, titanium alloy material and nickel-based alloy material, respectively, or the protective layer 21, the middle protective layer 22 and the outer protective layer 23 are made of magnesium alloy material, titanium alloy material and nickel-based alloy material, respectively.

[0042] Since all the protective layers on the protective sleeve 2 are made of alloy materials, they can be assembled using a set process. The inner protective layer 21 is set on the outside of the main body 1. Furthermore, the inner protective layer 21 is heated and set on the outside of the two shaft end pieces 12 of the main body 1, and the inner protective layer 21 and the main body 1 have an interference fit; the middle protective layer 22 is heated and set on the outside of the inner protective layer 21, and the two have an interference fit, and the outer protective layer 23 is heated and set on the outside of the middle protective layer 22, and the two have an interference fit. In this way, multiple protective layers and the inner protective layer 21 and the main body 1 can be quickly installed by heating sets. Compared with the winding manufacturing of fiber materials, the manufacturing difficulty of the utility model is greatly reduced.

[0043] Furthermore, in this embodiment, the yield strength of the outer protective layer 23 is greater than or equal to 1200Mpa, the yield strength of the middle protective layer 22 is greater than or equal to 800Mpa, the yield strength of the inner protective layer 21 is greater than or equal to 400Mpa, and the hardness of the multiple protective layers is 55HRC or above. In this way, the design of increasing the yield strength of multiple alloy material protective layers from the inside to the outside can greatly reduce the stress span of the protective cover, reduce the stress span of the protective cover, reduce the stress difference between the inner side and the outer side of the protective cover, and ensure the strength of the protective layer itself with sufficient hardness, so that the protective cover itself is more evenly stressed, which greatly improves the utilization rate, reliability and service life of the rotor of the protective cover.

[0044] Furthermore, the outer diameter of the protective sleeve 2 is greater than or equal to 20 mm and less than or equal to 100 mm, and the ratio of the thickness of the inner protective layer 21, the thickness of the middle protective layer 2 and the thickness of the outer protective layer 23 is 1:1.5:2.9. Under this setting, the stress span of the protective sleeve and the eddy current loss of the rotor are more effectively reduced.

[0045] Rotor Second Embodiment

[0046] See also Figure 3 and Figure 4 Different from the first embodiment, in this embodiment, the protective cover 3 only includes two protective layers: an inner protective layer 31 and an outer protective layer 32 .

[0047] Furthermore, the yield strength of the outer protective layer 32 is greater than or equal to 1200 MPa, and the yield strength of the inner protective layer 31 is greater than or equal to 900 MPa.

[0048] Furthermore, the ratio of the thickness of the inner protective layer 31 to the thickness of the outer protective layer 32 is 1:1.8.

[0049] In addition, in this embodiment, the interference between the inner protective layer 31 and the outer protective layer 32 is 0.15 mm to 0.25 mm, and the interference between the inner protective layer 31 and the main body is 0.2 mm to 0.35 mm. The appropriate interference between the protective layers and between the protective layer and the main body is selected according to the strength of each material to ensure the reliability of the rotor as a whole.

[0050] See also Figures 5 to 7 , Figures 5 to 7 The stress cloud diagrams corresponding to the inner protective layer 21, the middle protective layer 22 and the outer protective layer 23 in the first embodiment of the rotor are shown in FIG. Figure 8 and Fig. 9 , Figure 8 and Fig. 9 The stress cloud diagrams of the inner protective layer 31 and the outer protective layer 32 respectively correspond to the second embodiment of the rotor; see Fig.10 , Fig.10 This is the stress cloud diagram of the existing single-layer alloy protective cover.

[0051] according to Fig.10 As shown, the stress span between the outer side and the inner side of the existing single-layer alloy protective sleeve is: 614.4-483.3=131.1.

[0052] according to Figures 5 to 7 As shown, in the first embodiment, the stress span between the outer side and the inner side of the inner protective layer 21 is 63.31-31.74=31.57, the stress span between the outer side and the inner side of the middle protective layer 22 is 828-766.8=61.2, and the stress span between the outer side and the inner side of the outer protective layer 23 is 939.5-841.7=97.8.

[0053] according to Figure 8 and Fig. 9 As shown, in the second embodiment, the stress span between the outer side and the inner side of the inner protective layer 31 is 523.8-466.5=57.3, and the stress span between the outer side and the inner side of the outer protective layer 32 is 629.7-534.5=95.2.

[0054] It can be seen that the three-layer protective cover structure effectively reduces the stress span of the protective cover by at least 25.5~80%, and the double-layer alloy protective cover structure effectively reduces the stress span of the protective cover by at least 27.4~56%. Both can make the stress on the protective cover more uniform and improve the utilization rate of the protective cover.

[0055] See also Fig.11The eddy current loss simulation calculation is performed on the rotor with a single layer, a three-layer alloy protective cover 2 in the first embodiment, and a two-layer alloy protective cover 3 in the second embodiment. The results show that when the traditional single-layer protective cover structure is adopted, the total loss is 141.288W; when the rotor structure of the second embodiment is a two-layer alloy protective cover 3, the total loss is 139.117W, which is about 1.5% lower than the loss of the single-layer protective cover structure; when the rotor structure of the three-layer alloy protective cover 2 in the first embodiment is adopted, the total loss is 137.688W, which is about 2.5% lower than the loss of the single-layer protective cover structure. It can be seen that the utility model further reduces the heat generation of the rotor and improves the reliability of the rotor operation.

[0056] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rotor, comprising a main body and a protective cover arranged outside the main body, wherein the protective cover comprises at least two protective layers arranged in sequence from inside to outside; Features: All the protective layers are made of alloy material, and adjacent protective layers and the protective layers and the main body are sleeved and interference fit; From the inside to the outside, the yield strength of the plurality of protective layers increases sequentially.

2. The rotor according to claim 1, characterized in that: The protective layer of the protective sleeve has two layers, the yield strength of the outer protective layer is greater than or equal to 1200Mpa, and the yield strength of the inner protective layer is greater than or equal to 900Mpa; or, The protective layer of the protective sleeve consists of three layers, the yield strength of the outer protective layer is greater than or equal to 1200Mpa, the yield strength of the middle protective layer is greater than or equal to 800Mpa, and the yield strength of the inner protective layer is greater than or equal to 400Mpa.

3. The rotor according to claim 1, characterized in that: The hardness of the plurality of protective layers is 55HRC or above.

4. The rotor according to any one of claims 1 to 3, characterized in that: The protective sleeve has two protective layers, the interference between the two protective layers is between 0.15 mm and 0.25 mm, and the interference between the inner protective layer and the main body is between 0.2 mm and 0.35 mm.

5. The rotor according to any one of claims 1 to 3, characterized in that: The outer diameter of the protective sleeve is greater than or equal to 20 mm and less than or equal to 100 mm.

6. The rotor according to any one of claims 1 to 3, characterized in that: The protective layer of the protective cover has two layers, and the ratio of the thickness of the inner protective layer to the thickness of the outer protective layer is 1:1.8; or, The protective layer of the protective cover consists of three layers, and the ratio of the thickness of the inner protective layer, the thickness of the middle protective layer and the thickness of the outer protective layer is 1:1.5:2.

9.

7. The rotor according to any one of claims 1 to 3, characterized in that: The protective layer of the protective sleeve is composed of two layers, the inner protective layer is made of titanium alloy material, and the outer protective layer is made of alloy steel material; or, The protective layer of the protective sleeve is composed of two layers, the inner protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material; or, The protective layer of the protective sleeve is three-layered, the inner protective layer is made of aluminum alloy material, the middle protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material; or, The protective layer of the protective sleeve has three layers, the inner protective layer is made of magnesium alloy material, the middle protective layer is made of titanium alloy material, and the outer protective layer is made of nickel-based alloy material.

8. The rotor according to any one of claims 1 to 3, characterized in that: The main body comprises a permanent magnet and two shaft end pieces respectively arranged on both sides of the permanent magnet in the axial direction, and the protective sleeve is interference-fitted with the shaft end pieces.

9. A motor, characterized in that The invention comprises a rotor as claimed in any one of claims 1 to 8.

10. A compressor, characterized in that The motor comprises the motor as claimed in claim 9 above.

11. An electrical appliance, characterized in that The compressor comprises the compressor as claimed in claim 10 above.

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