Rotor with enhanced heat exchange structure

Abstract

The application provides a motor rotor, which belongs to the technical field of impellers and is a rotor with a heat exchange structure, comprising a rotor body, a magnetic steel arranged at the middle part of the rotor body in the length direction, a sheath arranged on the rotor body, the sheath comprising an end section, a middle section and a transition section connected between the end section and the middle section, the thickness of the middle section being greater than that of the end section, and grooves being arranged on the outer periphery of the middle section and uniformly distributed along the length direction of the sheath, and the projection of the grooves in the direction perpendicular to the axial direction of the rotor body covering at least the area where the magnetic steel is arranged. The rotor with the heat exchange structure has the advantages that the specific shape of the sheath forms a cooling air flow channel which is gradually reduced and then gradually expanded, and the grooves arranged on the middle section corresponding to the magnetic steel increase the heat dissipation effect of the rotor, especially the magnetic steel.

Description

Technical Field

[0001] This application relates to the field of impeller technology, and more specifically to a rotor with an enhanced heat exchange structure. Background Technology

[0002] In existing technologies, the internal leakage air at the impeller outlet is directly utilized to flow through the air gap between the rotor magnets and the motor stator, cooling the rotor magnets through convection heat transfer. However, the amount of internal leakage air in the impeller is limited, and its temperature is mostly above 100°C. Furthermore, the surfaces of both the rotor and stator are relatively smooth, resulting in a low convection heat transfer coefficient and poor heat transfer efficiency. During operation, eddy current losses and hysteresis losses generated by the rotor magnets are converted into heat, causing the magnet temperature to rise continuously. When the temperature reaches a certain level, it can weaken or even demagnetize the permanent magnets, leading to rotor failure. Utility Model Content

[0003] In view of this, this application provides a rotor with a reinforced heat exchange structure, which forms a cooling airflow channel that gradually narrows and then expands with the motor stator through the specific shape of the sheath, and further enhances the heat dissipation effect on the rotor, especially the magnet part, by setting a groove in the middle section corresponding to the magnet.

[0004] To achieve the above objectives, this application provides the following technical solution: A rotor with an enhanced heat transfer structure includes: The rotor body has a magnet disposed at the middle of its length direction; A sheath is fitted onto the rotor body. The sheath includes an end section, a middle section, and a transition section connecting the end section and the middle section. The thickness of the middle section is greater than the thickness of the end section. Grooves evenly distributed along the length of the sheath are formed on the outer periphery of the middle section. The projection of the groove on the axis perpendicular to the rotor body at least covers the area where the magnet is located.

[0005] Optionally, the thickness of the middle section is 4-4.5 mm.

[0006] Optionally, the groove is a spiral groove that extends from one end of the middle section along its length to the other end.

[0007] Optionally, the cross-sectional shape of the spiral groove is one of rectangular, trapezoidal, semi-circular, U-shaped, or V-shaped.

[0008] Optionally, the cross-sectional shape of the helical groove is rectangular, and the groove width W1 of the helical groove satisfies: 1.4mm≤W1≤1.6mm; and / or, the groove depth D1 of the helical groove satisfies: 1.4mm≤D1≤1.6mm; and / or, the pitch L1 of the helical groove satisfies: 4.5mm≤L1≤5.5mm; and / or, the angle A1 between the groove line of the helical groove and the axis of the rotor body satisfies: 70°≤A1≤80°.

[0009] Optionally, the groove is a plurality of annular grooves that are evenly distributed and parallel to each other along the length of the middle section.

[0010] Optionally, a connecting groove may be provided between adjacent annular grooves.

[0011] Optionally, the angle between the axis of the annular groove and the axis of the sheath is 0°.

[0012] Optionally, the cross-sectional shape of the annular groove is one of a rectangle, trapezoid, semi-circle, U-shape, or V-shape.

[0013] Optionally, the cross-sectional shape of the annular groove is rectangular, and the groove width W2 of the annular groove satisfies: 2.5mm≤W2≤3.5mm; and / or, the groove depth D2 of the annular groove satisfies: 1.4mm≤D2≤1.6mm; and / or, the rib thickness T2 between adjacent annular grooves satisfies: 2.5mm≤T2≤3.5mm.

[0014] The rotor with enhanced heat exchange structure provided in this application has a segmented sheath outside the rotor body. This allows the cooling airflow entering the impeller to be pressurized and accelerated before flowing through the gap between the motor stator and rotor, and then depressurized before exiting the impeller, thereby carrying away some of the rotor's heat. Simultaneously, grooves are provided circumferentially in the middle section of the sheath corresponding to the magnets. This increases the heat exchange area of ​​the cooling air and the surface gas turbulence, increasing the Reynolds number and thus the convective heat transfer coefficient, enhancing heat exchange. In particular, the area with grooves on the sheath at least covers the area where the magnets are located. This not only reduces the temperature of the entire rotor, but especially the temperature of the magnets. Lowering the magnet temperature improves motor lifespan, increases efficiency, and allows for higher power density. This has significant benefits in terms of reducing motor costs and improving motor efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the rotor with enhanced heat exchange structure of this application assembled in the motor stator.

[0017] Figure 2 A schematic diagram of a rotor body with a spiral groove on the middle section of the sheath.

[0018] Figure 3 A schematic diagram of a rotor body with an annular groove on the middle section of the sheath.

[0019] Figure 4 for Figure 3 Cross-sectional view of the middle sheath.

[0020] Figure 5 This is a temperature distribution diagram inside a motor with an existing structure.

[0021] Figure 6 This is a temperature distribution diagram inside the motor of this application.

[0022] exist Figures 1-6 middle: 1. Motor stator; 2. Rotor body; 21. Magnet; 3. Sheath; 31. First end section; 32. First transition section; 33. Middle section; 34. Second transition section; 35. Second end section; 4. Groove; 41. Spiral groove; 42. Annular groove. Detailed Implementation

[0023] This application provides a rotor with a reinforced heat exchange structure. The specific shape of the sheath forms a cooling airflow channel with the motor stator that first gradually narrows and then gradually expands. In addition, a groove is provided in the middle section corresponding to the magnet, thereby increasing the heat dissipation effect on the rotor, especially the magnet part.

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] like Figure 1 As shown, the rotor with enhanced heat exchange structure provided in this application includes a rotor body 2 and a sheath 3 sleeved around the outer periphery of the rotor body 2, wherein: A magnet 21 is provided at the middle of the rotor body 2 along its length; The sheath 3 includes an end section, a middle section 33, and a transition section connecting the end section and the middle section 33. The thickness of the middle section 33 is greater than the thickness of the end section. The rotor body 2 and the sheath 3 sleeved on its outer periphery together form the rotor with enhanced heat exchange structure of this application, and are installed as a whole inside the motor stator 1. Specifically, such as Figure 1 As shown, the sheath 3 consists of a first end section 31, a first transition section 32, a middle section 33, a second transition section 34, and a second end section 35 from left to right. The first end section 31, the first transition section 32, and the middle section 33 of the sheath 3 on the motor inlet side form a gradually narrowing airflow channel with the inner wall of the motor stator 1. On the other hand, the middle section 33, the second transition section 34, and the second end section 35 of the sheath 3 on the motor outlet side form a gradually expanding airflow channel with the inner wall of the motor stator 1. In this way, the airflow is first pressurized and accelerated to flow through the gap between the motor stator 1 and the rotor, and then depressurized and flows out. The outer periphery of the middle section 33 is provided with grooves 4 evenly distributed along the length of the sheath 3. The grooves 4 can be a spiral groove 41 extending along the length of the middle section 33 or several parallel spiral grooves 41, or several parallel annular grooves 42. The projection of the groove 4 on the axis perpendicular to the rotor body 2 at least covers the area where the magnet 21 is located.

[0026] In this application, the outer sheath 3 of the rotor body 2 is segmented, so that the cooling airflow entering the impeller is first pressurized and accelerated to flow through the gap between the motor stator 1 and the rotor, and then flows out of the impeller after depressurization, thereby carrying away part of the rotor's heat. At the same time, grooves 4 are provided around the middle section 33 of the sheath 3 corresponding to the magnet 21. This increases the heat exchange area of ​​the cooling air and the degree of surface gas turbulence, increases the Reynolds number, and thus increases the convective heat transfer coefficient and enhances heat transfer. In particular, the area on the sheath 3 with grooves 4 at least covers the area where the magnet 21 is located. This not only reduces the temperature of the entire rotor, but also reduces the temperature of the magnet 21. By reducing the temperature of the magnet 21, the motor life can be improved, efficiency can be increased, and higher power density can be allowed. This has significant effects on reducing motor costs and improving motor efficiency.

[0027] In a preferred embodiment, the thickness of the middle section 33 is 4-4.5 mm.

[0028] In order to maintain a suitable gap size between the motor stator 1 and the sheath 3, and since the groove 4 mentioned above needs to be provided in the middle section 33, the depth of the groove 4 also needs to be considered. It is advisable to set the thickness of the middle section 33 to 4-4.5mm. In this embodiment, the thickness of the middle section 33 is preferably 4.2mm.

[0029] In a preferred embodiment, such as Figure 2As shown, the groove 4 is a spiral groove 41, which extends from one end of the middle section 33 along its length to the other end. In this embodiment, only one spiral groove 41 is provided on the middle section 33. Of course, multiple parallel spiral grooves 41 can also be provided on the middle section 33 of the sheath 3 according to the actual situation. The spiral groove 41 can increase the surface heat exchange area of ​​the sheath 3 and enhance the degree of cooling air turbulence between the motor stator 1 and the sheath 3, thereby enhancing the heat dissipation effect of the sheath 3, the rotor body 2, and especially the magnet 21. On the other hand, the machining of the spiral groove 41 is relatively easy.

[0030] In a preferred embodiment, the cross-sectional shape of the spiral groove 41 is one of rectangular, trapezoidal, semi-circular, U-shaped or V-shaped. Regardless of the cross-sectional shape, it can increase the surface heat exchange area of ​​the sheath 3, enhance the degree of cooling air turbulence between the motor stator 1 and the sheath 3, and enhance the heat dissipation effect of the sheath 3, rotor body 2, and especially the magnet 21.

[0031] The cross-sectional shape of the spiral groove 41 can be selected according to the actual situation. In this embodiment, for ease of processing, the cross-sectional shape of the spiral groove 41 is set to a rectangle or a square.

[0032] In a preferred embodiment, in order to increase the degree of cooling gas turbulence during rotation, the spiral groove 41 has a rectangular cross-sectional shape, and the groove width W1 of the spiral groove 41 satisfies: 1.4mm≤W1≤1.6mm; and / or, the groove depth D1 of the spiral groove 41 satisfies: 1.4mm≤D1≤1.6mm; and / or, the pitch L1 of the spiral groove 41 satisfies: 4.5mm≤L1≤5.5mm; and / or, the angle A1 between the groove line of the spiral groove 41 and the axis of the rotor body 2 satisfies: 70°≤A1≤80°.

[0033] In this embodiment, the groove width W1 of the spiral groove 41 is 1.5mm, the groove depth D1 is 1.5mm, the pitch L1 is 5.0mm, the angle A1 between the groove line of the spiral groove 41 and the axis of the rotor body 2 is 75°, and the temperature of the rotor magnet 21 is detected and compared with the temperature of the rotor magnet 21 in the prior art. In the existing technology, the heat dissipation effect of the groove structure 4 on the sheath 3 is not provided, such as... Figure 5 As shown, the temperature of magnet 21 can reach 160°C; and in this embodiment, the heat dissipation effect after setting the groove 4 structure on the sheath 3 is as follows: Figure 6 As shown, the temperature of magnet 21 decreased to 154°, which improved the heat dissipation effect of magnet 21.

[0034] In another preferred embodiment, such as Figure 3 and Figure 4As shown, the groove 4 consists of multiple annular grooves 42 that are evenly distributed and parallel to each other along the length of the middle section 33.

[0035] Similar to the spiral groove 41, the annular groove 42 can also increase the surface heat exchange area of ​​the sheath 3 and enhance the cooling air turbulence between the motor stator 1 and the sheath 3, thereby enhancing the heat dissipation effect of the sheath 3, the rotor body 2, and especially the magnet 21. On the other hand, the annular groove 42 is also easier to machine.

[0036] Furthermore, a connecting groove is provided between adjacent annular grooves 42.

[0037] In order to further increase the surface heat exchange area of ​​the sheath 3 and enhance the cooling air turbulence between the motor stator 1 and the sheath 3, a connecting groove is opened between adjacent annular grooves 42 to connect the adjacent annular grooves 42 to each other, so that the cooling airflow can flow from one annular groove 42 to the adjacent annular groove 42. The connecting groove can be parallel to the axis of the sheath 3, or it can be at an angle to the axis of the sheath 3; each connecting groove can be set on the same straight line, or it can be staggered from each other, or it can be evenly distributed in the circumference of the middle section 33 of the sheath 3.

[0038] In a preferred embodiment, such as Figure 3 As shown, the angle between the axis of the annular groove 42 and the axis of the sheath 3 is 0, that is, the plane in which each annular groove 42 is located is perpendicular to the axis of the sheath 3, which makes it easier to process. Of course, the axis of the annular groove 42 can also be set to have an angle with the axis of the sheath 3, thereby enhancing the degree of cooling air turbulence between the motor stator 1 and the sheath 3.

[0039] In a preferred embodiment, the cross-sectional shape of the annular groove 42 is one of rectangular, trapezoidal, semi-circular, U-shaped, or V-shaped. Regardless of the cross-sectional shape, it can increase the surface heat exchange area of ​​the sheath 3, enhance the degree of cooling air turbulence between the motor stator 1 and the sheath 3, and enhance the heat dissipation effect of the sheath 3, the rotor body 2, and especially the magnet 21.

[0040] In a preferred embodiment, in order to increase the degree of cooling air turbulence during the rotation of the spiral groove in the middle section, the cross-sectional shape of the annular groove 42 is rectangular, and the groove width W2 of the annular groove 42 satisfies: 2.5mm≤W2≤3.5mm; and / or, the groove depth D2 of the annular groove 42 satisfies: 1.4mm≤D2≤1.6mm; and / or, the rib thickness T2 between adjacent annular grooves 42 satisfies: 2.5mm≤T2≤3.5mm.

[0041] Specifically, in a more preferred embodiment, the cross-sectional shape of the annular groove 42 is rectangular, the groove width W2 of the annular groove 42 is set to 3mm, the groove depth D2 of the annular groove 42 is set to 1.5mm, and the rib thickness T2 between adjacent annular grooves 42 is set to 3.0mm.

[0042] In this embodiment, the groove depth D2 of the annular groove 42 has the same range as the groove depth D1 of the spiral groove 41 in another embodiment. The difference is that since the annular grooves 42 are independent of each other and the cooling airflow cannot flow, the groove width can be set to be wider, and the rib thickness can be set to be wider accordingly, so as to avoid the airflow being blocked and make the airflow smoother.

[0043] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0044] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the word “or” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0045] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled or recombined. These disassemblies or recombinations should be considered as equivalent solutions of this application.

[0046] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0047] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0048] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A rotor with an enhanced heat transfer structure, characterized in that, include: The rotor body has a magnet disposed at the middle of its length direction; A sheath is fitted onto the rotor body. The sheath includes end sections at both ends along the length of the sheath, a middle section in the middle along the length of the sheath, and a transition section connecting the end sections and the middle section. The thickness of the middle section is greater than the thickness of the end sections. Grooves evenly distributed along the length of the sheath are formed on the outer periphery of the middle section. The projection of the groove on the axis perpendicular to the rotor body at least covers the area where the magnet is located.

2. The rotor with enhanced heat exchange structure according to claim 1, characterized in that, The thickness of the middle section is 4-4.5 mm.

3. The rotor with enhanced heat exchange structure according to claim 2, characterized in that, The groove is a spiral groove that extends from one end of the middle section along its length to the other end.

4. The rotor with enhanced heat exchange structure according to claim 3, characterized in that, The cross-sectional shape of the spiral groove is one of rectangular, trapezoidal, semi-circular, U-shaped, or V-shaped.

5. The rotor with enhanced heat exchange structure according to claim 3, characterized in that, The cross-sectional shape of the helical groove is rectangular, and the groove width W1 of the helical groove satisfies: 1.4mm≤W1≤1.6mm; and / or, the groove depth D1 of the helical groove satisfies: 1.4mm≤D1≤1.6mm; and / or, the pitch L1 of the helical groove satisfies: 4.5mm≤L1≤5.5mm; and / or, the angle A1 between the groove line of the helical groove and the axis of the rotor body satisfies: 70°≤A1≤80°.

6. The rotor with enhanced heat exchange structure according to claim 2, characterized in that, The groove is a plurality of annular grooves that are evenly distributed and parallel to each other along the length of the middle section.

7. The rotor with enhanced heat exchange structure according to claim 6, characterized in that, A connecting groove is also provided between adjacent annular grooves.

8. The rotor with enhanced heat exchange structure according to claim 6, characterized in that, The angle between the axis of the annular groove and the axis of the sheath is 0°.

9. The rotor with an enhanced heat exchange structure according to claim 6, characterized in that, The cross-sectional shape of the annular groove is one of the following: rectangular, trapezoidal, semi-circular, U-shaped, or V-shaped.

10. The rotor with an enhanced heat exchange structure according to claim 6, characterized in that, The cross-sectional shape of the annular groove is rectangular, and the groove width W2 of the annular groove satisfies: 2.5mm≤W2≤3.5mm; and / or, the groove depth D2 of the annular groove satisfies: 1.4mm≤D2≤1.6mm; and / or, the rib thickness T2 between adjacent annular grooves satisfies: 2.5mm≤T2≤3.5mm.

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