Axial flux motor hybrid cooling system for low-altitude aircraft and stator structure

Abstract

The invention relates to the technical field of axial flux motors, in particular to an axial flux motor hybrid cooling system for a low-altitude aircraft and a stator structure. The motor comprises an upper end cover and a lower end cover arranged on one side of the upper end cover, and the upper end cover and the lower end cover are matched with a rotor assembly and a stator assembly to form a mixed cooling mechanism. The specially-made stator is matched with the heat pipe, the stator can be positioned without affecting a magnetic circuit, installation is easy and convenient, the process requirement is low, the method can meet the motor cooling requirement, the problems that an existing liquid cooling structure is complex, the installation process is difficult, reliability is low, and the cooling result is poor are solved, and the motor cooling efficiency is improved. The problems that the temperature of the two sides is uneven are solved, through the unique stator shape, the stator can be matched with a round wire winding and a flat wire winding, the heat pipe is matched with the inner ring and the outer ring of the shell so that positioning can be well achieved, more positioning devices are not needed, the structure is simple and reliable, and good popularization value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of axial flux motors, and in particular to a hybrid cooling system and a stator structure of an axial flux motor for low-altitude aircraft. Background Art

[0002] Conventional fuel-powered low-altitude aircraft have large vibration and noise, high flight costs, and serious environmental pollution. In addition, the drive motor will generate a large amount of heat during continuous operation. If the motor temperature is too high, it will affect the motor's reliability and power performance. In order to maintain the normal operation of the motor, a reasonable cooling structure needs to be designed to cool the motor.

[0003] At present, the most commonly used cooling method for low-altitude aircraft is water cooling. However, as the power of the motor increases, the effect of water cooling can no longer meet the heat dissipation requirements of the motor. Oil is not conductive, so the cooling oil can directly contact the motor components and directly take away the heat of the motor components. Therefore, the cooling effect of the oil cooling system is far better than water cooling, and it has become the development trend of the motor cooling system.

[0004] Existing oil-cooled motors generally use oil pipes for oil spray cooling. The cooling oil is transported into the oil pipes, and then the oil is sprayed from the oil spray holes on the oil pipes to spray the oil onto the motor windings and other components for cooling. However, this cooling method requires the design and installation of additional oil pipes, so the structure is relatively complex, the installation process is difficult, and the reliability is low; and the use of oil pipes for oil spraying can generally only spray the cooling oil onto the surface of the motor components, and the cooling effect is not good. For this reason, we propose a hybrid cooling system and stator structure for axial flux motors for low-altitude aircraft. The present invention uses more air for air cooling, which is more energy-saving and environmentally friendly. In addition, the problem of uneven temperature on both sides of the motor caused by air cooling, that is, the different structures of the end covers on both sides, can also be solved by the design of the end covers. Summary of the invention

[0005] The object of the present invention is to provide a hybrid cooling system and a stator structure of an axial flux motor for low-altitude aircraft to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A hybrid cooling system for an axial flux motor for a low-altitude aircraft comprises an upper end cover (1) and a lower end cover (7) arranged on one side of the upper end cover (1), a rotor assembly (6) being arranged between the upper end cover (1) and the lower end cover (7), a hybrid cooling mechanism being arranged between the upper end cover (1) and the lower end cover (7), the hybrid cooling mechanism comprising a passive air cooling component and an oil cooling component, an outer ring (2) being fixed between the upper end cover (1) and the lower end cover (7), an inner ring (4) being arranged on the inner side of the outer ring (2), a passive air cooling component and an oil cooling component being arranged between the outer ring (2) and the inner ring (4), the passive air cooling component and the oil cooling component both being used for heat dissipation of the axial flux motor.

[0008] Preferably, the passive air cooling component comprises a heat pipe (8), a loop heat pipe (9) and a heat dissipation fin (10); a plurality of heat pipes (8) and a loop heat pipe (9) are evenly arranged on the outer sides of the outer ring (2) and the inner ring (4); a plurality of heat dissipation fins (10) are evenly fixed on one end of the heat pipe (8) and the loop heat pipe (9); the outer ring (2) and the inner ring (4) are used to cooperate with the heat pipe (8) and the loop heat pipe (9) to perform mutual positioning and together constitute a stator assembly.

[0009] Preferably, the oil cooling assembly comprises a first annular guide groove (11), a first oil passage (12), a first oil spray port (13) and a first oil spray hole (14); a first annular guide groove (11) is provided on a side of the upper end cover (1) away from the lower end cover (7); a first oil passage (12) is fixed on the inner side of the first annular guide groove (11); a plurality of first oil spray ports (13) are evenly fixed on a side of the first oil passage (12) close to the upper end cover (1); a plurality of first oil spray ports (14) corresponding to the positions of the first oil spray ports (13) are evenly provided on the inner side of the first annular guide groove (11); and the first oil spray ports (14) are transitionally matched with the first oil spray ports (13).

[0010] Preferably, the oil cooling assembly further comprises a spiral oil passage (15), a second annular guide groove (16), a second oil passage (17) and a second oil spray port (18); a spiral oil passage (15) is provided on the inner side of the lower end cover (7); the inner side of the lower end cover (7) is connected to the spiral oil passage (15); a second annular guide groove (16) is provided on the outer side of the lower end cover (7); a second oil passage (17) is fixed on the inner side of the second annular guide groove (16); a plurality of second oil spray ports (18) are evenly distributed and fixed on the inner side of the second oil passage (17); the second oil spray ports (18) are all connected to the inner side of the lower end cover (7).

[0011] Preferably, the distance between one end of the inner side of the spiral oil passage (15) and the side surface of the lower end cover (7) is smaller than the distance between the other end of the inner side of the spiral oil passage (15) and the side surface of the lower end cover (7).

[0012] Preferably, a rotor back iron is arranged on the outer side of the rotor assembly (6), and a plurality of rotating heat pipes (19) are evenly distributed on the inner side of the rotor back iron.

[0013] The stator structure of an axial flux motor for low-altitude aircraft is suitable for a hybrid cooling system of an axial flux motor for low-altitude aircraft, comprising a winding (3) and a stator (5), wherein a plurality of windings (3) are evenly distributed and fixed between an outer ring (2) and an inner ring (4), and a stator (5) is arranged on the inner side of each winding (3).

[0014] Preferably, a positioning mechanism is arranged between the outer ring (2) and the inner ring (4), and the positioning mechanism comprises an inner protrusion (20), an outer protrusion (21) and a limiting protrusion sheet (22); a plurality of limiting protrusion sheets (22) are evenly distributed and fixed on the outer side of the inner ring (4); an inner protrusion (20) is fixed between two adjacent limiting protrusion sheets (22); a plurality of outer protrusions (21) are evenly distributed and fixed on the outer side of the outer ring (2); and the inner protrusions (20) and the outer protrusions (21) are both in close contact with the winding (3).

[0015] Preferably, both upper and lower sides of the stator (5) are provided with small through slots, and both the inner protrusion (20) and the outer protrusion (21) are transitionally matched with the small slots.

[0016] It can be seen without a doubt that the above-mentioned technical solution of the present application can definitely solve the technical problem to be solved by the present application.

[0017] At the same time, through the above technical solutions, the present invention has at least the following beneficial effects:

[0018] 1. The present invention uses a special stator with a heat pipe to position the stator without affecting the magnetic circuit, and is easy to install with low process requirements. This method can meet the cooling needs of the motor and solve the problems of complex cooling structure, difficult installation process, low reliability, poor cooling results, and uneven temperature on both sides of the existing liquid cooling.

[0019] 2. The present invention can be adapted to both round wire and flat wire windings through its unique stator shape, and the heat pipe can be well positioned by cooperating with the inner and outer rings of the shell, without the need for additional positioning devices. The structure is simple and reliable, and has good promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a schematic diagram of the explosion structure of the present invention;

[0023] Figure 3 It is a schematic diagram of the connection structure between the outer ring and the heat pipe of the present invention;

[0024] Figure 4 It is a schematic diagram of the structure of the heat pipe of the present invention;

[0025] Figure 5 It is a schematic diagram of the connection structure of the loop heat pipe and the heat dissipation fin of the present invention;

[0026] Figure 6 It is a schematic diagram of the connection structure of the winding and the stator of the present invention;

[0027] Figure 7 It is a structural schematic diagram of the stator of the present invention;

[0028] Figure 8 It is a schematic diagram of the connection structure between the first oil passage and the first annular guide groove of the present invention;

[0029] Fig. 9 It is a schematic diagram of the cutaway structure of the lower end cover of the present invention;

[0030] Fig.10 It is a schematic diagram of the connection structure between the second oil passage and the second oil injection port of the present invention;

[0031] Fig.11 It is a schematic diagram of the connection structure between the inner ring and the inner protrusion of the present invention;

[0032] Fig.12 It is a schematic diagram of the connection structure of the rotor assembly and the rotating heat pipe of the present invention.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] In the figure: 1. upper end cover; 2. outer ring; 3. winding; 4. inner ring; 5. stator; 6. rotor assembly; 7. lower end cover; 8. heat pipe; 9. loop heat pipe; 10. cooling fin; 11. first annular guide groove; 12. first oil channel; 13. first oil injection port; 14. first oil injection hole; 15. spiral oil channel; 16. second annular guide groove; 17. second oil channel; 18. second oil injection port; 19. rotating heat pipe; 20. inner protrusion; 21. outer protrusion; 22. limiting protrusion. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] Example 1

[0037] Reference Figure 1-12 A hybrid cooling system for an axial flux motor for a low-altitude aircraft comprises an upper end cover 1 and a lower end cover 7 arranged on one side of the upper end cover 1, a rotor assembly 6 is arranged between the upper end cover 1 and the lower end cover 7, a hybrid cooling mechanism is arranged between the upper end cover 1 and the lower end cover 7, the hybrid cooling mechanism comprises a passive air cooling component and an oil cooling component, an outer ring 2 is fixed between the upper end cover 1 and the lower end cover 7, an inner ring 4 is arranged on the inner side of the outer ring 2, a passive air cooling component and an oil cooling component are arranged between the outer ring 2 and the inner ring 4, and both the passive air cooling component and the oil cooling component are used for heat dissipation of the axial flux motor.

[0038] The passive air cooling assembly includes a heat pipe 8, a loop heat pipe 9 and a heat dissipation fin 10. Multiple heat pipes 8 and loop heat pipes 9 are evenly arranged on the outer side of the outer ring 2 and the inner ring 4. Multiple heat dissipation fins 10 are evenly fixed on one end of the heat pipe 8 and the loop heat pipe 9. The outer ring 2 and the inner ring 4 are used to cooperate with the heat pipe 8 and the loop heat pipe 9 to play a mutual positioning role and jointly constitute the stator assembly. The bottom of the heat pipe 8 is inserted between the two groups of stators 5 and directly contacts the winding 3. It plays a cooling role and positions the stator 5 to prevent the position of the stator 5 from being disordered. The surface of the heat pipe 8 should be insulated to prevent conductivity. The upper part cooperates with the outer ring 2 for positioning, and the heat dissipation fins 10 are in contact with the air for heat exchange; the lower part of the loop heat pipe 9 cooperates with the outer side of the inner ring 4 and the limiting protrusion 22 for positioning. The upper part of the loop heat pipe 9, that is, the heat dissipation fin 10, is exposed outside the shell and contacts with the air for heat exchange.

[0039] The oil cooling assembly includes a first annular guide groove 11, a first oil passage 12, a first oil spray port 13 and a first oil spray hole 14. The first annular guide groove 11 is provided on the side of the upper end cover 1 away from the lower end cover 7. The first oil passage 12 is fixed on the inner side of the first annular guide groove 11. A plurality of first oil spray ports 13 are evenly fixed on the side of the first oil passage 12 close to the upper end cover 1. A plurality of first oil spray ports 14 corresponding to the positions of the first oil spray ports 13 are evenly provided on the inner side of the first annular guide groove 11. The first oil spray port 14 is transitionally matched with the first oil spray port 13. The first oil passage 12 and the first oil spray port 13 are used to cooperate with the first annular guide groove 11 for oil spraying; the first oil passage 12 is used to introduce cooling oil into the upper end cover 1.

[0040] The oil cooling assembly also includes a spiral oil passage 15, a second annular guide groove 16, a second oil passage 17 and a second oil injection port 18. A spiral oil passage 15 is provided on the inner side of the lower end cover 7, and the inner side of the lower end cover 7 is communicated with the spiral oil passage 15. A second annular guide groove 16 is provided on the outer side of the lower end cover 7, and a second oil passage 17 is fixed on the inner side of the second annular guide groove 16. A plurality of second oil injection ports 18 are evenly distributed and fixed on the inner side of the second oil passage 17, and the second oil injection ports 18 are all communicated with the inner side of the lower end cover 7. The second oil passage 17 and the second oil injection port 18 are used to cooperate with the second annular guide groove 16 for oil injection; the second oil passage 17 is used to recover oil in the lower end cover 7.

[0041] The distance between one end of the inner side of the spiral oil passage 15 and the side surface of the lower end cover 7 is smaller than the distance between the other end of the inner side of the spiral oil passage 15 and the side surface of the lower end cover 7. Through the setting of the spiral oil passage 15, cooling oil can be introduced for cooling according to the requirements of use. There are inclinations at both ends of the inner side of the spiral oil passage 15 for the reflux of oil sprayed from the upper end cover 1 and the lower end cover 7.

[0042] A rotor back iron is arranged on the outer side of the rotor assembly 6, and a plurality of rotating heat pipes 19 are evenly arranged on the inner side of the rotor back iron. The rotating heat pipes 19 are used to be inserted into the rotor back iron to extract the heat of the permanent magnet and 06, and to take away the heat extracted by the rotating heat pipes 19 by spraying oil through the end cover.

[0043] Example 2

[0044] Reference Figure 2 and Fig.11 The stator structure of the axial flux motor for low-altitude aircraft is suitable for the hybrid cooling system of the axial flux motor for low-altitude aircraft, including windings 3 and stators 5. Multiple windings 3 are evenly fixed between the outer ring 2 and the inner ring 4, and the stators 5 are arranged on the inner side of the windings 3.

[0045] A positioning mechanism is installed between the outer ring 2 and the inner ring 4, and the positioning mechanism includes an inner protrusion 20, an outer protrusion 21 and a limiting protrusion piece 22. A plurality of limiting protrusion pieces 22 are evenly fixed on the outer side of the inner ring 4, and an inner protrusion 20 is fixed between two adjacent limiting protrusion pieces 22. A plurality of outer protrusions 21 are evenly fixed on the outer side of the outer ring 2, and the inner protrusions 20 and the outer protrusions 21 are both in contact with the winding 3. The function of the limiting protrusion piece 22 is to cooperate with the heat pipe 8 and the loop heat pipe 9 to jointly position the stator 5.

[0046] The stator 5 is provided with small through slots on both the upper and lower sides, and the inner protrusion 20 and the outer protrusion 21 are transitionally matched with the small slots. The stator 5 is a yokeless type, and has small through slots on both the upper and lower sides for matching with the heat pipe 8 and the loop heat pipe 9.

[0047] From the above, we can know that:

[0048] The present invention is directed to the following technical problem: at present, the most commonly used cooling method for low-altitude aircraft is water cooling. However, as the motor power increases, the effect of water cooling can no longer meet the heat dissipation requirements of the motor. Oil is not conductive, so the cooling oil can directly contact the motor components and directly take away the heat of the motor components. Therefore, the cooling effect of the oil cooling system is much better than water cooling, and has become the development trend of the motor cooling system. Existing oil-cooled motors generally use oil pipes for oil spray cooling. The cooling oil is transported to the oil pipes, and then the oil is sprayed from the oil spray holes on the oil pipes to spray the oil onto the motor windings and other components for cooling. However, this cooling method requires the design and installation of additional oil pipes, so the structure is relatively complex, the installation process is difficult, and the reliability is low; and the use of oil pipes for oil spraying can generally only spray the cooling oil onto the surfaces of the motor components, and the cooling effect is poor; the technical solutions of the above-mentioned embodiments are adopted. At the same time, the implementation process of the above-mentioned technical solution is:

[0049] Rotor: The heat on the permanent magnet is conducted to the upper end of the heat pipe 8 through the rotating heat pipe 19 on the rotor back iron, and then the heat of the rotating heat pipe 19 is taken out with cooling oil through the upper end cover 1. The cooling oil is recovered through the lower end cover 7 to achieve the purpose of reducing the temperature of the permanent magnet.

[0050] Stator: By inserting two kinds of heat pipes, namely heat pipe 8 and loop heat pipe 9, heat pipe 8 and loop heat pipe 9 act as brackets, and the temperature of winding 3 is exported to the upper ends of heat pipe 8 and loop heat pipe 9. Heat dissipation fins 10 are provided at the upper ends of heat pipe 8 and loop heat pipe 9 and extend out of the entire motor housing. The heat is taken away by contact between heat dissipation fins 10 and air to achieve the purpose of cooling.

[0051] Through the above configuration, the present application can certainly solve the above technical problems and achieve the following technical effects:

[0052] 1. The present invention can achieve positioning 05 without affecting the magnetic circuit by combining a special stator with 08 and 09, and is easy to install and has low process requirements. This method can meet the cooling needs of the motor and solve the problems of complex cooling structure, difficult installation process, low reliability, poor cooling results, and uneven temperature on both sides of the existing liquid cooling.

[0053] 2. The present invention can be adapted to both round wire and flat wire windings through the unique 03 shape, and 08 and 09 can be well positioned in conjunction with the inner and outer rings of the shell, without the need for more positioning devices. The structure is simple and reliable, and has good promotion value.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific embodiments, or to perform equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of the present invention, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. Axial flux motor hybrid cooling system for low altitude aircraft, characterized in that: The invention comprises an upper end cover (1) and a lower end cover (7) arranged on one side of the upper end cover (1), a rotor assembly (6) being arranged between the upper end cover (1) and the lower end cover (7), a mixed cooling mechanism being arranged between the upper end cover (1) and the lower end cover (7), the mixed cooling mechanism comprising a passive air cooling component and an oil cooling component, an outer ring (2) being fixed between the upper end cover (1) and the lower end cover (7), an inner ring (4) being arranged on the inner side of the outer ring (2), a passive air cooling component and an oil cooling component being arranged between the outer ring (2) and the inner ring (4), the passive air cooling component and the oil cooling component being both used for heat dissipation of the axial flux motor.

2. The axial flux motor hybrid cooling system for low altitude aircraft according to claim 1 is characterized in that: The passive air cooling component comprises a heat pipe (8), a loop heat pipe (9) and a heat dissipation fin (10); a plurality of heat pipes (8) and a loop heat pipe (9) are evenly arranged on the outer sides of the outer ring (2) and the inner ring (4); a plurality of heat dissipation fins (10) are evenly fixed on one end of the heat pipe (8) and the loop heat pipe (9); the outer ring (2) and the inner ring (4) are used to cooperate with the heat pipe (8) and the loop heat pipe (9) to perform a mutual positioning function and together constitute a stator assembly.

3. The axial flux motor hybrid cooling system for low altitude aircraft according to claim 1, characterized in that: The oil cooling assembly comprises a first annular guide groove (11), a first oil passage (12), a first oil spray port (13) and a first oil spray hole (14); a first annular guide groove (11) is provided on a side of the upper end cover (1) away from the lower end cover (7); a first oil passage (12) is fixed on the inner side of the first annular guide groove (11); a plurality of first oil spray ports (13) are evenly distributed and fixed on a side of the first oil passage (12) close to the upper end cover (1); a plurality of first oil spray ports (14) corresponding to the positions of the first oil spray ports (13) are evenly distributed on the inner side of the first annular guide groove (11); and the first oil spray ports (14) are transitionally matched with the first oil spray ports (13).

4. The axial flux motor hybrid cooling system for low altitude aircraft according to claim 3 is characterized in that: The oil cooling assembly further comprises a spiral oil passage (15), a second annular guide groove (16), a second oil passage (17) and a second oil injection port (18); the inner side of the lower end cover (7) is provided with a spiral oil passage (15); the inner side of the lower end cover (7) is communicated with the spiral oil passage (15); the outer side of the lower end cover (7) is provided with a second annular guide groove (16); the inner side of the second annular guide groove (16) is fixed with a second oil passage (17); the inner side of the second oil passage (17) is evenly fixed with a plurality of second oil injection ports (18); the second oil injection ports (18) are all communicated with the inner side of the lower end cover (7).

5. The axial flux motor hybrid cooling system for low altitude aircraft according to claim 4 is characterized in that: The distance between one end of the inner side of the spiral oil passage (15) and the side surface of the lower end cover (7) is smaller than the distance between the other end of the inner side of the spiral oil passage (15) and the side surface of the lower end cover (7).

6. The axial flux motor hybrid cooling system for low altitude aircraft according to claim 1, characterized in that: A rotor back iron is arranged on the outer side of the rotor assembly (6), and a plurality of rotating heat pipes (19) are evenly distributed on the inner side of the rotor back iron.

7. The stator structure of the axial flux motor for low-altitude aircraft is applicable to the hybrid cooling system of the axial flux motor for low-altitude aircraft as claimed in any one of claims 1 to 6, characterized in that: It comprises windings (3) and a stator (5); a plurality of windings (3) are evenly distributed and fixed between the outer ring (2) and the inner ring (4); and a stator (5) is arranged on the inner side of each winding (3).

8. The stator structure of the axial flux motor for low-altitude aircraft according to claim 7, characterized in that: A positioning mechanism is arranged between the outer ring (2) and the inner ring (4), the positioning mechanism comprising an inner protrusion (20), an outer protrusion (21) and a limiting protrusion sheet (22); a plurality of limiting protrusion sheets (22) are evenly distributed and fixed on the outer side of the inner ring (4); an inner protrusion (20) is fixed between two adjacent limiting protrusion sheets (22); a plurality of outer protrusions (21) are evenly distributed and fixed on the outer side of the outer ring (2); the inner protrusions (20) and the outer protrusions (21) are both in close contact with the winding (3).

9. The stator structure of the axial flux motor for low-altitude aircraft according to claim 8, characterized in that: The stator (5) is provided with through-going small notches on both the upper and lower sides, and the inner protrusion (20) and the outer protrusion (21) are both transitionally matched with the small notches.

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