Squirrel cage rotor

Abstract

The utility model relates to the technical field of motors, and discloses a squirrel cage rotor which comprises an iron core and a squirrel cage, a plurality of conducting bar grooves are formed in the iron core, plug structures are arranged at the two ends of the iron core, and the yield strength of a manufacturing material of the plug structures is larger than that of a manufacturing material of the squirrel cage. The mouse cage comprises a plurality of conducting bars and end rings located at the two ends of the conducting bars, and the conducting bars are arranged in the corresponding conducting bar grooves in a penetrating mode; the plug structure comprises a plug ring and a plurality of plug teeth, the plug ring is located between the end ring and the iron core, the plug teeth are connected to the side, close to the iron core, of the plug ring, the plug teeth are inserted into the corresponding guide bar grooves, and the plug teeth are located on the radial outer sides of the guide bars. The problem that the joint of the conducting bar and the end ring in the cast-aluminum squirrel cage rotor is easy to break can be solved.

Description

Technical Field

[0001] The present application relates to the field of motors, and in particular to a squirrel cage rotor. Background Art

[0002] With the development of new energy vehicles, the speed requirements for motor rotors are becoming increasingly higher. For cast aluminum squirrel-cage rotors, the risk of deformation, cracking, and even fracture at the connection between the cage bars and the end rings increases dramatically with increasing rotor speed. This can severely reduce the performance and service life of the squirrel-cage rotor.

[0003] At present, the Chinese invention patent application with publication number CN115313710A discloses a cast aluminum rotor for a high-speed asynchronous motor, including a rotor core, which is in a cylindrical shape and has a plurality of guide bar grooves evenly distributed along the circumference of the outer periphery of the rotor core; the guide bar grooves are filled with aluminum bars, and end rings are connected to both ends of the rotor core, and the end rings are integrally formed with the aluminum bars; a plurality of copper bars are inserted into each guide bar groove, and the copper bars are located at the bottom and / or top of the guide bar groove; copper rings are provided at both ends of the rotor core, and the two ends of each copper bar are fixedly connected to the copper rings at both ends of the rotor core.

[0004] Regarding the related technologies mentioned above, the second copper bar needs to be inserted into the entire guide bar slot, which increases the amount of copper used and is not conducive to reducing the cost of rotor manufacturing. Moreover, the second copper bar is relatively thin and cannot support the aluminum bar well. The problem of easy breakage at the connection between the guide bar and the end ring in the cast aluminum squirrel cage rotor still exists. Utility Model Content

[0005] In order to alleviate the problem of easy breakage at the connection between the conductor bars and the end rings in a cast aluminum squirrel cage rotor, the present application provides a squirrel cage rotor.

[0006] The present application provides a squirrel cage rotor, which adopts the following technical solution:

[0007] A squirrel cage rotor comprises an iron core and a squirrel cage, wherein the iron core is formed with a plurality of guide bar slots, and plug structures are provided at both ends of the iron core, wherein the yield strength of the material of the plug structures is greater than the yield strength of the material of the squirrel cage, and the squirrel cage comprises a plurality of guide bars and end rings at both ends of the guide bars, wherein the guide bars are inserted into corresponding guide bar slots;

[0008] The plug structure includes a plug ring and a plurality of plug teeth. The plug ring is located between the end ring and the iron core. The plug teeth are connected to the side of the plug ring close to the iron core. The plug teeth are inserted into the corresponding guide bar grooves, and the plug teeth are located radially outside the guide bar.

[0009] By adopting the above technical solution, when the rotor rotates at high speed, the plug structure is used to support the connection between the end ring and the guide bar, thereby protecting the connection between the guide bar and the end ring, thereby reducing the risk of cracks or even breakage at the connection; in addition, after the cast aluminum squirrel cage is formed, the portion of the plug ring other than the outer circumference will be covered by the end ring, so that the plug ring acts as a reinforcing rib in the end ring, reducing the probability of the end ring breaking when the rotor rotates at high speed, thereby achieving the effect of improving the performance and service life of the rotor.

[0010] Optionally, the plug ring includes a plurality of plug segments arranged in sequence along the circumferential direction, and the plug segments are connected to a plurality of the plug teeth.

[0011] By adopting the above technical solution, the plug ring is spliced together from multiple plug segments. Compared with the one-piece plug ring, during the pouring of molten aluminum, the gaps between adjacent plug segments can accommodate the deformation of the plug segments caused by heat, thereby preventing the plug ring from moving during the pouring of molten aluminum and ensuring the assembly accuracy of the plug structure and the iron core.

[0012] Optionally, a recess is provided at one circumferential end of the plug segment, and a protrusion is provided at the other circumferential end of the plug segment, and two adjacent plug segments are detachably connected through the cooperation between the recess and the protrusion.

[0013] By adopting the above technical solution, the detachable connection of each plug segment is facilitated, and the difficulty of assembling the plug structure can be reduced.

[0014] Optionally, the radial thickness of the plug tooth gradually increases from an end of the plug tooth away from the plug ring to an end of the plug tooth close to the plug ring.

[0015] By adopting the above technical solution, the thickness of the plug teeth gradually increases in the axial direction of the iron core and reaches the maximum thickness at the connection between the guide bar and the end ring, thereby ensuring the stability of the connection between the guide bar and the end ring.

[0016] Optionally, the radial inner side surface of the plug tooth is a curved surface.

[0017] By adopting the above technical solution, the side surface of the plug tooth facing the center of the iron core is a smoothly transitioned curved surface. During the process of pouring molten aluminum into the guide bar groove, the curved surface can play a guiding role, thereby avoiding splashing of molten aluminum, improving the pouring efficiency and quality of molten aluminum, and increasing the contact area between the plug tooth and the guide bar, which helps to reduce the stress at the contact surface between the two.

[0018] Optionally, the radial outer side surface of the plug tooth fits into the inner wall of the guide bar groove.

[0019] By adopting the above technical solution, the outer side surface of the plug tooth is adapted to the shape of the top wall of the guide bar groove to ensure the fit between the outer side surface of the plug tooth and the guide bar groove, prevent the aluminum liquid from entering between the outer side surface of the plug tooth and the top wall of the guide bar groove, and avoid the movement of the plug structure during the pouring of aluminum liquid.

[0020] Optionally, in the axial direction of the iron core, the plug teeth are located at the ends of the guide bar slots.

[0021] Optionally, the axial length of the plug ring is smaller than the axial length of the end ring.

[0022] By adopting the above technical solution, it is possible to ensure that the axial end face of the plug ring is wrapped by the end ring, so that the plug ring is embedded in the end ring, which can ensure the connection strength between the plug structure and the squirrel cage.

[0023] Optionally, the outer diameter of the plug ring is equal to the diameter of the iron core, and the inner diameter of the plug ring is larger than the diameter of a circular ring formed by the radial inner sides of all the guide bar grooves.

[0024] By adopting the above technical solution, the volume of the end ring can be guaranteed while ensuring the structural strength of the plug ring, which helps to ensure the structural strength of the end ring and reduce the resistance of the end ring.

[0025] Optionally, the plug tooth is inserted into the guide bar groove before the guide bar.

[0026] By adopting the above technical solution, the plug structure and the squirrel cage are manufactured in stages, which helps to reduce the manufacturing difficulty of the squirrel cage rotor and improve the manufacturing efficiency of the squirrel cage rotor.

[0027] Optionally, the conductive bar and the end ring are made of pure aluminum, and / or the plug structure is made of copper.

[0028] By adopting this technical solution, the resistance of the bars and end rings can be reduced, helping to improve the performance of the squirrel-cage rotor. The use of pure aluminum also helps reduce squirrel-cage manufacturing costs. Because copper has a much greater tensile strength than aluminum, the use of a copper plug structure further reduces the risk of cracks or even breakage at the connection between the bars and end rings.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. When the rotor rotates at high speed, the plug structure supports and protects the connection between the end ring and the guide bar, thereby reducing the risk of cracks or even breakage at the connection. In addition, after the cast aluminum squirrel cage is formed, the plug ring is covered by the end ring except for its outer circumference, making the plug ring act as a reinforcement rib in the end ring, reducing the probability of end ring breakage during high-speed rotation of the rotor, thereby improving the performance and service life of the rotor.

[0031] 2. The plug ring is made of multiple plug segments. Compared with the one-piece plug ring, the gap between adjacent plug segments can accommodate the deformation of the plug segments after heating during the pouring of molten aluminum, which can prevent the plug ring from moving during the pouring of molten aluminum;

[0032] 3. By setting the side of the plug teeth facing the center of the iron core to a smoothly transitioned curved surface, the curved surface can play a guiding role in the process of pouring molten aluminum into the guide groove, thereby avoiding splashing of molten aluminum, improving the pouring efficiency and quality of molten aluminum. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0034] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0035] Figure 2 This is a schematic structural diagram of the core portion of an embodiment of the present application;

[0036] Figure 3 is a schematic diagram of the plug structure portion in an embodiment of the present application;

[0037] Figure 4 is a cross-sectional view of an embodiment of the present application;

[0038] Figure 5 This is a schematic structural diagram of the plug section in an embodiment of the present application;

[0039] Figure 6 It is a structural schematic diagram of the connection between the plug structure and the iron core part in the embodiment of the present application.

[0040] Reference numerals: 100, iron core; 110, guide bar groove; 200, squirrel cage; 210, guide bar; 220, end ring; 300, plug structure; 310, plug ring; 320, plug tooth; 330, plug segment; 331, recess; 332, protrusion. DETAILED DESCRIPTION

[0041] In order to more clearly explain the overall concept of this application, the following Figure 1-6 This application is described in further detail.

[0042] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible embodiments of the present application, nor to limit the scope of the present application.

[0043] The following is a detailed description of the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems with specific embodiments. It should be noted that, in the absence of conflict, the following embodiments may refer to, draw on, or combine with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be repeated.

[0044] Unless otherwise specified, the axial, radial and circumferential directions mentioned in the embodiments of the present application are all referenced to the axial, radial and circumferential directions of the iron core.

[0045] The present application discloses a squirrel cage rotor. Figures 1-4 A squirrel cage rotor includes an iron core 100, a cage 200, and a plug structure 300. The iron core 100 is formed with a plurality of axially extending guide bar slots 110. The cage 200 includes the same number of guide bars 210 as the guide bar slots 110, with each guide bar 210 being installed in a one-to-one correspondence within the guide bar slots 110. The cage 200 also includes two end rings 220, one at each axial end of the iron core 100, and each guide bar 210 is connected to an end ring 220 at each axial end.

[0046] In some embodiments of the present application, the cage 200 is formed by casting, for example, by casting aluminum, aluminum alloy, or other materials to form an integrally formed cage 200 , thereby ensuring the connection strength between the guide bars 210 and the end rings 220 .

[0047] Reference Figure 1 and Figure 3A plug structure 300 is installed at each axial end of the core 100. The plug structure 300 includes a plug ring 310 and a plurality of plug teeth 320 arranged corresponding to the guide bar slots 110. In the axial direction of the core 100, the plug ring 310 is located between the end ring 220 and the core 100. The plug teeth 320 are located radially outward from the guide bars 210, so that the plug ring 310 and the plug teeth 320 jointly protect the connection between the guide bars 210 and the end ring 220. Since the yield strength of the manufacturing material of the plug structure 300 is greater than the yield strength of the manufacturing material of the cage 200, for example, the plug structure 300 is made of pure copper or a copper alloy. When the rotor rotates at high speed, the plug structure 300 supports the connection between the end ring 220 and the guide bars 210, thereby protecting the connection between the guide bars 210 and the end ring 220, thereby reducing the risk of cracks or even breakage at the connection. In addition, after the cast aluminum cage 200 is formed, the portion of the plug ring 310 other than the outer circumference will be covered by the end ring 220, so that the plug ring 310 acts as a reinforcing rib in the end ring 220, reducing the probability of the end ring 220 breaking when the rotor rotates at high speed, thereby improving the performance and service life of the rotor.

[0048] Moreover, if Figure 4 As shown, along the axial direction, the plug teeth 320 are only located at the two ends of the guide bar groove 110 , which can ensure the volume of the guide bar 210 in the guide bar groove 110 and help to ensure the structural strength of the guide bar 210 .

[0049] In the squirrel-cage rotor provided in this embodiment, before the squirrel cage 200 is formed, the plug structures 300 are installed at both axial ends of the core 100, so that a plug tooth 320 is inserted into each axial end of each guide bar slot 110. In some embodiments of the present application, the plug structure 300 is an integrally formed structure, which facilitates the manufacture and installation of the plug structure 300 and helps ensure the overall structural strength of the plug structure 300.

[0050] In some embodiments of the present application, reference Figure 4 and Figure 6 The plug ring 310 includes multiple plug segments 330, which are assembled sequentially along the circumference of the core 100. A recess 331 is provided at one end of each plug segment 330, and a protrusion 332 is provided at the other end. Adjacent plug segments 330 are detachably connected by the engagement of the recess 331 and the protrusion 332. Compared to an integrally formed plug ring 310, a gap exists between each plug segment 330. This gap allows for deformation of the heated plug segments 330 during the pouring of molten aluminum to form the cage 200. This prevents movement of the plug ring 310 due to expansion during the pouring process, ensuring the precision of the cage 200.

[0051] Reference Figures 3 to 5 The plug tooth 320 is fixedly connected to the side of the plug segment 330 closest to the core 100. The plug tooth 320 is inserted into its corresponding guide bar slot 110. In the radial direction of the core 100, the guide bar 210 is located inward of the plug tooth 320. The thickness of the plug tooth 320 gradually increases from the end of the plug tooth 320 away from the plug segment 330 to the end closer to the plug segment 330. In the axial direction of the core 100, the thickness of the plug tooth 320 gradually increases, reaching its maximum thickness at the junction of the guide bar 210 and the end ring 220, thereby ensuring the stability of the connection between the guide bar 210 and the end ring 220.

[0052] Reference Figure 5 and Figure 6 The side surface of the plug tooth 320 facing the center of the iron core 100 is a smoothly transitioned curved surface. During the process of pouring molten aluminum into the guide groove 110, the curved surface can play a guiding role, thereby avoiding splashing of molten aluminum, improving the pouring efficiency of molten aluminum, and improving the pouring quality of molten aluminum.

[0053] Furthermore, by setting the radial inner side surface of the plug tooth 320 to be a curved surface, the contact area between the plug tooth 320 and the connection between the guide bar 210 and the end ring 220 can be increased, which helps to release stress at the connection between the guide bar 210 and the end ring 220.

[0054] Those skilled in the art will appreciate that existing squirrel-cage rotors are often manufactured from aluminum alloy to enhance the structural strength of the cage 200. However, aluminum alloys are relatively expensive and have a higher electrical resistance than pure aluminum. This results in greater heating of the cage 200, increasing losses in the squirrel-cage rotor and hindering the improvement of the rotor's power.

[0055] In this embodiment, due to the presence of the plug structure 300, the guide bars 210 and end rings 220 can be cast from pure aluminum. Compared to casting the cage 200 from an aluminum alloy, using pure aluminum significantly reduces the manufacturing cost and difficulty of the cage rotor, thereby improving the production efficiency of the cage rotor. Pure aluminum has a purity of 99.0%. Using pure aluminum to manufacture the cage 200 also reduces the resistance and heat generation of the cage 200, thereby improving the performance of the cage rotor.

[0056] Reference Figure 5 and Figure 6The side of the plug tooth 320 facing away from the center of the core 100 is in contact with the inner wall of the guide bar slot 110. The outer side of the plug tooth 320 is adapted to the shape of the top wall of the guide bar slot 110 to ensure the fit between the outer side of the plug tooth 320 and the guide bar slot 110, preventing molten aluminum from entering between the outer side of the plug tooth 320 and the top wall of the guide bar slot 110, and thus preventing the plug structure 300 from moving during the pouring of molten aluminum.

[0057] It should be noted that the squirrel cage rotor provided in the embodiment of the present application is first manufactured to form the iron core 100 and the plug structure 300 separately, and then the two are assembled and placed in a casting mold, and then cast to form the squirrel cage 200 through a pressure casting or centrifugal casting process.

[0058] Reference Figure 5 and Figure 6 In the axial direction of the core 100 , the plug teeth 320 are located at the ends of the guide bar slots 110 . The axial length of the plug ring 310 is not greater than the axial length of the end ring 220 .

[0059] In this embodiment, the outer diameter of the plug ring 310 is equal to the diameter of the core 100, ensuring that the outer circumference of the plug ring 310 is coplanar with the outer circumference of the core 100. This prevents the squirrel-cage rotor from being too large in diameter and helps ensure an air gap between the squirrel-cage rotor and the stator in the motor. The inner diameter of the plug ring 310 is larger than the diameter of the circular ring formed by the radially inner sides of all the guide bar slots 110, ensuring the connection strength between the end ring 220 and the guide bar 210.

[0060] In this embodiment, the plug segment 330 and the plug teeth 320 are integrally formed, thereby ensuring the overall structural strength of the plug structure 300 while improving the production efficiency of the plug structure 300. Of course, in some embodiments of the present application, the plug segment 330 and the plug teeth 320 can also be integrally formed by casting.

[0061] Anything not described in this application can be achieved by adopting or drawing on existing technologies.

[0062] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A squirrel cage rotor, characterized in that: The invention comprises an iron core (100) and a cage (200), wherein the iron core (100) is formed with a plurality of guide bar slots (110), plug structures (300) are provided at both ends of the iron core (100), the yield strength of the manufacturing material of the plug structure (300) is greater than the yield strength of the manufacturing material of the cage (200), and the cage (200) comprises a plurality of guide bars (210) and end rings (220) located at both ends of the guide bars (210), and the guide bars (210) are inserted into corresponding guide bar slots (110); The plug structure (300) comprises a plug ring (310) and a plurality of plug teeth (320); the plug ring (310) is located between the end ring (220) and the iron core (100); the plug teeth (320) are connected to a side of the plug ring (310) close to the iron core (100); the plug teeth (320) are plugged into corresponding guide bar slots (110); and the plug teeth (320) are located radially outside the guide bar (210).

2. The squirrel cage rotor according to claim 1, characterized in that: The plug ring (310) comprises a plurality of plug segments (330) arranged in sequence along the circumferential direction, and the plug segments (330) are connected to a plurality of the plug teeth (320).

3. The squirrel cage rotor according to claim 2, characterized in that: A recess (331) is provided at one circumferential end of the plug segment (330), and a convex portion (332) is provided at the other circumferential end of the plug segment (330). Two adjacent plug segments (330) are detachably connected through the cooperation of the recess (331) and the convex portion (332).

4. The squirrel cage rotor according to claim 1, characterized in that: The radial thickness of the plug tooth (320) gradually increases from one end of the plug tooth (320) away from the plug ring (310) to one end close to the plug ring (310).

5. The squirrel cage rotor according to claim 1, characterized in that: The radial inner side surface of the plug tooth (320) is a curved surface.

6. The squirrel cage rotor according to claim 1, characterized in that: The radial outer side surface of the plug tooth (320) is in contact with the inner wall of the guide groove (110).

7. The squirrel cage rotor according to claim 1, characterized in that: The axial length of the plug ring (310) is smaller than the axial length of the end ring (220).

8. The squirrel cage rotor according to claim 1, characterized in that: The outer diameter of the plug ring (310) is equal to the diameter of the iron core (100), and the inner diameter of the plug ring (310) is greater than the diameter of a circular ring formed by the radial inner sides of all the guide bar grooves (110).

9. The squirrel cage rotor according to claim 1, characterized in that: The plug tooth (320) is inserted into the guide bar groove (110) before the guide bar (210).

10. The squirrel cage rotor according to claim 1, characterized in that: The conductive bar (210) and the end ring (220) are made of pure aluminum, and / or the plug structure (300) is made of copper.

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