An internal cooling structure for a motor rotor

Abstract

The present invention discloses an internal cooling structure for a motor rotor, which includes a plurality of ventilation holes axially arranged on the rotor. The inlets of the ventilation holes are evenly distributed on the circumferences on both sides of the rotor. The inner diameter of each ventilation hole gradually decreases from the outside to the inside and reaches the minimum cross-sectional area at the axial center. Two ventilation holes on the same axis are symmetrically distributed. The outlets of the plurality of ventilation holes are connected and communicated inside the rotor. Circular radiators that are respectively in close contact and flow are provided on the front and rear end faces of the rotor. The present invention realizes ventilation by opening retracted through ventilation holes in the rotor, and optimizes the internal heat exchange efficiency of the rotor on the basis of ensuring that the original space size of the motor rotor is not increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor rotor cooling, and particularly relates to a retractable through ventilation hole cooling structure for a motor rotor. Background Art

[0002] Generally, when the motor is in operation, the rotor, which is the core working component, needs to keep running continuously. During operation, continuous losses occur and are converted into heat energy, thereby causing the temperature of the rotor to rise. Especially in the design of high-speed motors, excessive temperature reduces the operating safety of the motor, so the temperature inside the rotor requires special attention.

[0003] In a high-speed rotating rotor, it is difficult to use liquid media such as water or oil to cool the rotor. Therefore, air cooling is generally used to cool the rotor, and a special air duct design is implemented to enhance the heat exchange capacity of air cooling.

[0004] There are mainly two ventilation methods inside the rotor: axial ventilation and radial ventilation. The currently used axial ventilation generally has a relatively long cooling path and requires a large air pressure to compensate for the losses caused by the ventilation channels. For example, means such as a fan are used at the front side of the rotor to enhance the ventilation and heat exchange effect. However, for some motor rotors with limited cavity space, it is difficult to set up a complex air duct to enhance heat exchange, resulting in difficulties in cooling the rotor.

[0005] Existing patent means only provide the rotor cavity, but do not conduct research on optimizing and improving the air flow structure inside the rotor, resulting in insufficient air flow inside the cavity and poor heat exchange effect. Summary of the Invention

[0006] In order to overcome the deficiencies of the existing technology, enhance the heat exchange capacity inside the motor rotor, and improve the working environment of the motor, the present invention proposes an internal cooling structure for a motor rotor.

[0007] The technical solution adopted by the present invention to solve its technical problems is: an internal cooling structure for a motor rotor, including a plurality of ventilation holes axially arranged on the rotor. The inlets of the ventilation holes are evenly distributed on the circumferences on both sides of the rotor. The inner diameter of each ventilation hole gradually decreases from the outside to the inside, and the cross-sectional area reaches the minimum at the axial center. Two ventilation holes on the same axis are symmetrically distributed, that is, the axially corresponding ventilation holes have the same size and shape. The internal cooling fluid is air, forming a constricted through-air cooling channel. The outlets of the plurality of ventilation holes are connected and communicated inside the rotor. Circular radiating fins that fit and flow are respectively arranged on the front and rear end faces of the rotor. The radiating fins include a central hole communicated with the inlet and outlet and a plurality of heat exchange fins wound around the central hole. The heat exchange fins are distributed on a plurality of circumferences concentric with the central hole. The heat exchange fins on each circumference have an arc-shaped cross-section and the same size. The radius of the circular ring gradually expands from the center to the outside. The heat exchange fins of each layer of the circular ring have the same radius and thickness. An air duct is formed between two adjacent heat exchange fins on each circumference. The air ducts of multiple layers of heat exchange fins are located on a radius of the circular ring.

[0008] For the internal cooling structure of a motor rotor described above, the number of ventilation holes is six or more.

[0009] For the internal cooling structure of a motor rotor described above, the ventilation holes are of the same composition and have the same cross-section.

[0010] For the internal cooling structure of a motor rotor described above, the distance between each layer of heat exchange fins is consistent.

[0011] For the internal cooling structure of a motor rotor described above, the distance between two adjacent heat exchange fins on each circumference is consistent.

[0012] For the internal cooling structure of a motor rotor described above, there are 5 layers of heat exchange fins, and 16 pieces in each layer.

[0013] The beneficial effects of the present invention are: The present invention realizes ventilation by opening constricted through ventilation holes in the rotor, and optimizes the internal heat exchange efficiency of the rotor on the basis of ensuring that the space size of the original motor rotor is not increased. The constricted through ventilation hole cooling structure of the present invention can lay an air path for the air inside the rotor, strengthen the fluid flow rate in the ventilation holes, thereby enhancing the heat exchange capacity and achieving the effect of improving the over-high temperature of the rotor. Description of the Drawings

[0014] Figure 1 is a perspective view of the present invention;

[0015] Figure 2 is a front view of the present invention;

[0016] Figure 3 is a schematic internal structure diagram of the rotor of the present invention;

[0017] Figure 4 It is a side view of the rotor of the present invention;

[0018] Figure 5 It is a perspective view of the annular heat sink of the present invention;

[0019] Figure 6 It is a side view of the annular heat sink of the present invention.

[0020] Each reference numeral is: 1 - rotor, 2 - ventilation hole, 3 - heat sink, 31 - heat exchange fin, 32 - central hole. Detailed implementation manners

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0022] As Figures 1 to 4 shown, an internal cooling structure of a motor rotor disclosed by the present invention includes six or more ventilation holes 2 axially and vertically penetrating nearly half of the rotor 1. Each ventilation hole has the same structure and the same cross-section. The inlets of the ventilation holes 2 are evenly distributed on the circumferences on both sides of the rotor 1. The inner diameter of each ventilation hole 2 gradually decreases from the outside to the inside, and the cross-sectional area reaches the minimum at the axial center. Two ventilation holes 2 on the same axis are symmetrically distributed, that is, the axially corresponding ventilation holes 2 have the same size and shape. The internal cooling fluid is air, forming a contracted-through air-cooling channel. The outlets of multiple ventilation holes 2 are connected to each other inside the rotor 1.

[0023] A through hole is arranged at the axis center of the rotor 1 of the present invention, and a part of the rotor 1 can be hollowed out to obtain a cylindrical part concentric with the through hole. The cylindrical part is fixed by radially arranged support plates. The inner diameter of the cylindrical part gradually decreases from the outside to the inside to zero, that is, the cylindrical part forms an integral structure with the rotor 1 in the middle section. In this way, ventilation holes 2 are formed between two adjacent support plates and the rotor 1 and the cylindrical part: the fluid enters from the outer side wall surfaces at both ends of the ventilation hole 2, flows towards the inner side wall surface after reaching the outermost center, and finally flows out along the inner side wall surface to the outside of the rotor 1, that is, the air on the outside of the motor enters and exits on the same side.

[0024] The fluid enters the ventilation hole 2 from the outside due to centrifugal force and flows along the outer side wall surface of the ventilation hole 2 towards the center of the ventilation hole 2. After the fluid reaches the axial center of the rotor 1, it will meet the oncoming flow from the other side, causing the oncoming flows on both sides to flow out in the reverse direction along the inner side wall surface of the ventilation hole 2. During this period, the cross-sectional area of the ventilation hole 2 gradually decreases when the fluid flows in, resulting in a gradual increase in the fluid flow velocity, so as to ensure that the fluid can still maintain a relatively large velocity at the axial center of the rotor 1, thereby improving the internal heat exchange capacity.

[0025] Furthermore, the sizes and shapes of the ventilation holes 2 on both sides may be different; the sizes and shapes of the ventilation holes 2 on the same circular side may be different; a linear contraction method may also be set on the wall surface of the ventilation holes 2, or different curve forms may be used to achieve the contraction of the cross-section of the ventilation holes 2; the ventilation holes 2 on both sides may or may not penetrate, and whether the center penetrates is adjusted by modifying the contraction degree of different inclination angles.

[0026] As Figure 5 and Figure 6 shown, in the present invention, annular radiators 3 that fit and flow are respectively provided on the front and rear end faces of the rotor 1. The radiator 3 includes a central hole 32 communicated with the inlet and outlet and a plurality of heat exchange fins 31 wound around the central hole 32. The heat exchange fins 31 are distributed on a plurality of circumferences concentric with the central hole 32. Each heat exchange fin 31 on each circumference has an arc-shaped cross-section and the same size. The radius of the ring gradually expands from the center to the outside. Each heat exchange fin 31 on each layer of the ring has the same radius and thickness. An air duct is formed between two adjacent heat exchange fins 31 on each circumference. The air ducts of the multi-layer heat exchange fins 31 are located on a radius of the ring, and the distance between each layer of heat exchange fins 31 is the same. The distance between two adjacent heat exchange fins 31 on each circumference is the same. Preferably, there are 5 layers of heat exchange fins 31, and 16 pieces on each layer.

[0027] Furthermore, the heat exchange fins 31 of the radiator 3 may not adopt a uniformly distributed form, but a heat dissipation form suitable for the corresponding flow; the distance between two adjacent layers of heat exchange fins 31 may not be fixed, and a cross-arrangement form may be adopted.

[0028] In addition, it should be noted that the above-described internal cooling structure uses specific examples to elaborate on the present invention. The above embodiments are only for helping to understand the method and core idea of the present invention; at the same time, any person of ordinary skill in the art will make changes in specific implementation and application based on the idea of the present invention, and such should all belong to the protection scope of the present invention. In summary, the description in the present invention specification should not be a limitation to the protection scope of the present invention.

Claims

1. An internal cooling structure for a motor rotor, comprising a plurality of ventilation holes (2) axially arranged on the rotor (1), the inlets of the ventilation holes (2) being evenly distributed on the circumferences on both sides of the rotor (1), characterized in that: The inner diameter of each ventilation hole (2) gradually decreases from both ends of the rotor (1) towards the middle. Two ventilation holes (2) on the same axis are symmetrically distributed. The outlets of multiple ventilation holes (2) are connected and communicated inside the rotor (1). Circular fin radiators (3) are respectively arranged on the front and rear end faces of the rotor. The fin radiator (3) includes a central hole (32) communicated with the inlet and outlet of the ventilation hole (2) and multiple heat exchange fins (31) wound around the central hole (32). The heat exchange fins (31) are distributed on multiple circumferences concentric with the central hole (32). The heat exchange fins (31) on each circumference have an arc-shaped cross section and the same size. An air duct is formed between two adjacent heat exchange fins (31) on each circumference. The air ducts of multiple layers of heat exchange fins (31) are located on a radius of the ring.

2. The internal cooling structure of a motor rotor according to claim 1, characterized in that, The number of the ventilation holes (2) is six or more.

3. The internal cooling structure of an electric motor rotor according to claim 2, characterized in that, The cross section of each ventilation hole (2) is the same.

4. The internal cooling structure of a motor rotor according to claim 1, characterized in that, The distance between two adjacent heat exchange fins (31) in each layer is consistent.

5. The internal cooling structure of a motor rotor according to claim 1, characterized in that, The distance between two adjacent heat exchange fins (31) on each circumference is consistent.

6. The internal cooling structure of a motor rotor according to claim 4 or 5, characterized in that, The heat exchange fins (31) have 5 layers, and each layer has 16 pieces.

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