Lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors in drones

Abstract

This invention discloses a lightweight topological heat pipe sleeve thin-shell radiator for a high-specific-power motor of an unmanned aerial vehicle (UAV), comprising a primary heat pipe and a secondary heat pipe. This lightweight topological heat pipe sleeve thin-shell radiator for a high-specific-power motor of an UAV achieves heat dissipation for the motor based on the primary and secondary heat pipes. The high-specific-power motor of the UAV operates in a near-space atmospheric environment. The radiator of this invention significantly increases the heat dissipation area required for heat pipe air cooling while improving the heat pipe's temperature uniformity and heat dissipation efficiency. Compared with traditional heat pipe finned cooling, its heat dissipation capacity is increased by more than 10 times, and it can effectively and quickly remove heat generated inside the motor even under the thin atmosphere of high altitudes.

Description

Technical Field

[0001] This invention belongs to the technical field of unmanned aerial vehicles (UAVs), heat pipes and heat dissipation devices, and particularly relates to a lightweight topological heat pipe sleeve thin-shell heat sink for high specific power motors of UAVs. Background Technology

[0002] Near-space long-endurance unmanned aerial vehicles (UAVs) are characterized by long flight distances, extended loiter times, and uninterrupted operation. The significant contradiction between payload and power supply levels places higher demands on the propulsion system for weight reduction, efficiency improvement, and energy saving. The propulsion motor is the core power component of near-space vehicles, presenting two major challenges: how to increase specific power and how to improve operational efficiency. A key bottleneck hindering these two challenges is the internal heat dissipation of the motor. Furthermore, the atmospheric density in near-space above 20 kilometers is only about 1 / 15 of that at ground level. This thin air significantly reduces the convection coefficient of traditional air-cooled systems, exacerbating the motor's heat dissipation problem. Optimizing the internal airflow structure of the motor and increasing the power and speed of the cooling fan are merely simple improvements and cannot fundamentally solve or effectively improve the thermal problem.

[0003] Currently, motor cooling primarily employs air cooling. One method involves designing air-cooled fins on the motor casing to increase the surface area for convective heat exchange with the environment; another method uses a fan arranged coaxially with the shaft to create an internal airflow field. Because the coil windings are tightly packed and stacked in the motor stator slots, the actual airflow inside the motor can only pass through the edges of the coils and the gaps between different slots. Furthermore, heat transfer between the tightly packed conductors within the windings is still mainly conduction. Therefore, even under ground conditions with constant air density, the cooling of the coil windings remains inadequate. To improve the efficiency of dissipating the heat generated by the winding conductors into the ambient heat sink, heat pipes, as a high thermal conductivity element, have been introduced into motor stator cooling, significantly enhancing heat dissipation.

[0004] Numerous published documents and patents exist regarding the use of heat pipes in motors. These documents and patents exhibit the following characteristics: First, the heat pipes primarily employ conventional straight cylindrical heat pipes; second, the motors mostly operate on the ground, and the design of the heat pipe condensation section either integrates with water cooling or utilizes air cooling through finned condensation sections; third, heat pipe cooling for UAVs has not yet addressed the challenges posed by the thin atmospheric environment and the demand for high specific power motors. To improve the specific power of propulsion motors for near-space UAVs, two approaches are proposed: first, minimizing the motor's size and weight while maintaining consistent power; second, changing the traditional external stator / internal rotor motor design to an external rotor / internal stator configuration to increase motor torque, stator density, and space utilization. These changes in near-space UAV motors imply greater heat generation within a smaller weight, as the internal stator cannot dissipate heat through the motor casing, exacerbating thermal issues within the more compact space. Therefore, conventional simple heat pipe designs are insufficient to meet their heat dissipation requirements. Coupled with the harsher atmospheric environment of near-space, developing a novel lightweight, high-performance heat pipe design specifically for near-space thin atmospheres is essential. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs. While greatly increasing the heat dissipation area required for heat pipe air cooling, it also improves the heat pipe temperature uniformity and heat dissipation efficiency. Compared with the traditional heat pipe condenser fin heat dissipation, the heat dissipation capacity is increased by more than 10 times. Even under the thin atmosphere at high altitudes, it can effectively and quickly remove the heat generated inside the motor.

[0006] To address the aforementioned technical problems, this invention discloses a lightweight topological heat pipe sleeve thin-shell radiator for a high-specific-power motor of an unmanned aerial vehicle (UAV), comprising: a primary heat pipe and a secondary heat pipe; wherein, the lightweight topological heat pipe sleeve thin-shell radiator for a high-specific-power motor of an UAV achieves heat dissipation for the high-specific-power motor of the UAV based on the primary heat pipe and the secondary heat pipe; the high-specific-power motor of the UAV operates in the near-space atmospheric environment.

[0007] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the high specific power motor of the UAV includes: an inner stator, an outer rotor, a motor shaft, and a motor housing; wherein, the inner stator and the outer rotor are disposed within the motor housing; the inner stator is located within the outer rotor; the rotation of the outer rotor drives the motor shaft to rotate, thereby driving the rotation of the UAV propeller.

[0008] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the primary heat pipe includes a heating section A and a condensing section A that are smoothly connected; the secondary heat pipe includes a heating section B and a condensing section B that are smoothly connected; wherein, the heating section A is in contact with the inner stator and absorbs the heat generated by the inner stator coil in the form of thermal conduction; the heating section B is in contact with the condensing section A and absorbs the heat transferred by the primary heat pipe in the form of thermal conduction; the condensing section B extends along the envelope of the motor housing in a biomimetic topology, that is, it first bends outward from the tail end of the motor housing, and then bends along the axial direction of the high specific power motor of the UAV to extend towards the front end of the motor housing.

[0009] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the primary heat pipes are arranged in a multi-ring pattern; the heating section A is designed as a cylindrical heat pipe that penetrates into the inner stator, or is closely attached to the circumferential outer surface of the inner stator, or is closely attached to the rear outer surface of the inner stator; the outer surface of the condensation section A is embedded in the inner surface of the heating section B, and they are fixed together by welding or riveting.

[0010] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, both the primary heat pipe and the secondary heat pipe are designed as upper and lower halves, that is, heating section A, condensing section A, heating section B and condensing section B are all designed as upper and lower halves; among them, the upper and lower halves of condensing section B and the upper and lower halves of heating section B respectively form an integral topological heat pipe.

[0011] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the upper and lower halves of the secondary heat pipe are designed as an integral ultra-thin flat plate heat pipe with a vacuum cavity structure inside, incorporating capillary wicks and a heat pipe working medium.

[0012] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the upper and lower halves of the secondary heat pipe are designed as a combined structure of ultra-thin metal plates and pulsating heat pipes; wherein, the outer surface of the pulsating heat pipe is embedded in the inner surface of the ultra-thin metal plate and welded together.

[0013] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the thickness of the ultra-thin metal plate is 0.5–1.0 mm; the outer diameter of the pulsating heat pipe is 2–4 mm.

[0014] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the secondary heat pipe is a three-dimensional structure of a circular ring sleeve thin shell, and the upper and lower halves of the secondary heat pipe are each half of a three-dimensional structure of a circular ring sleeve thin shell.

[0015] In the aforementioned lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs, the encapsulation metal material of the primary heat pipe and the secondary heat pipe is copper alloy, aluminum alloy or titanium alloy; the two-phase working medium of the primary heat pipe and the secondary heat pipe is distilled water, ammonia, acetone, ethanol or Freon; both the primary heat pipe and the secondary heat pipe adopt a thin-shell design, and the weight of the entire radiator does not exceed 100g.

[0016] The present invention has the following advantages:

[0017] (1) This invention discloses a lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs. It is the first to disclose a new type of heat pipe radiator for UAV motors that are designed for use in the harsh environment of near-space thin atmosphere. While greatly increasing the heat dissipation area required for heat pipe air cooling, it also improves the heat pipe temperature uniformity and heat dissipation efficiency. Compared with the traditional heat pipe condenser fin heat dissipation, the heat dissipation capacity of the radiator of this invention is increased by more than 10 times. Even under the conditions of thin atmosphere at high altitude, it can quickly and effectively remove the heat generated inside the motor.

[0018] (2) This invention discloses a lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs. It innovatively designs a two-stage heat pipe topological sleeve thin-shell structure, which realizes uniform heat dissipation of large-area heat pipes, thereby greatly improving the heat dissipation capacity, while also having the advantage of light weight. The topological configuration realizes the design of being coaxial with the motor and biomimetic in shape, which is equivalent to putting a thin "outer coat" on the motor, minimizing the flow resistance during flight. The sleeve thin shell adopts a two-half design scheme instead of an integrated design, which improves the feasibility of heat sink processing and manufacturing, as well as the convenience of installation and maintenance.

[0019] (3) This invention discloses a lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs. Compared with traditional motors, motors using the radiator of this invention can eliminate the fins on the motor housing and the cooling fan on the motor. While supporting effective heat dissipation of the motor, it improves the output torque and the compactness of the motor structure, realizes the weight reduction and efficiency improvement of the motor, and improves the specific power index of the motor in near-space UAV applications. Attached Figure Description

[0020] Figure 1 This is a front view of a lightweight topological heat pipe sleeve thin-shell radiator for a high specific power motor of an unmanned aerial vehicle (UAV) according to an embodiment of the present invention.

[0021] Figure 2 yes Figure 1 Sectional view along axis AA;

[0022] Figure 3 This is a schematic diagram of the coupling between a primary heat pipe and a secondary heat pipe in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of a combined two-stage heat pipe according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a traditional heat pipe air cooling solution in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0026] Reference Figures 1-3 In this embodiment, the lightweight topological heat pipe sleeve thin-shell radiator for the high specific power motor of the UAV includes: a primary heat pipe 101 and a secondary heat pipe 102. The lightweight topological heat pipe sleeve thin-shell radiator for the high specific power motor of the UAV uses the primary heat pipe 101 and the secondary heat pipe 102 to dissipate heat from the high specific power motor of the UAV; the high specific power motor of the UAV operates in the near-space atmospheric environment with harsh heat dissipation conditions and a low mass flow rate of the rarefied air 110.

[0027] In this embodiment, the high specific power motor for the UAV specifically includes: an inner stator 103, an outer rotor 104, a motor shaft 105, and a motor housing 106. The inner stator 103 and outer rotor 104 are disposed within the motor housing 106; the inner stator 103 is located within the outer rotor 104; the rotation of the outer rotor 104 drives the motor shaft 105 to rotate, thereby driving the rotation of the UAV propeller 107. Designing the motor in an inner stator + outer rotor operating mode helps to improve the compactness of the motor winding arrangement, increase the rotor's output torque, thereby reducing the motor's size and weight, and significantly improving the motor's specific power performance; however, the heat flux density generated by the inner stator increases, and the heat from the inner stator cannot be dissipated through a traditional motor housing.

[0028] In this embodiment, the primary heat pipe 101 specifically includes a heating section A1011 and a condensing section A1012 that are smoothly connected; the secondary heat pipe 102 specifically includes a heating section B1021 and a condensing section B1022 that are smoothly connected. Heating section A1011 contacts the inner stator 103 and absorbs the heat generated by the inner stator coil through thermal conduction; heating section B1021 contacts the condensing section A1012 and absorbs the heat transferred by the primary heat pipe 101 through thermal conduction; condensing section B1022 extends along the envelope of the motor housing 106 in a biomimetic topology, that is, it first bends outward from the tail end of the motor housing 106, and then bends along the axial direction of the high-power motor of the UAV towards the front end of the motor housing 106. This achieves a topological streamline biomimetic design for a lightweight topological heat pipe sleeve thin-shell radiator for the high-power motor of the UAV. The topological streamline biomimetic design can reduce the drag caused by adding a radiator during UAV flight.

[0029] In this embodiment, the primary heat pipes 101 are arranged in a multi-ring pattern. The heating section A1011 is designed as a cylindrical heat pipe that extends into the inner stator 103, or is tightly attached to the circumferential outer surface of the inner stator 103, or is tightly attached to the rear outer surface of the inner stator 103. The outer surface of the condensing section A1012 is embedded in the inner surface of the heating section B1021, and they are fixed together by welding or riveting.

[0030] In this embodiment, considering the convenience of installation and arrangement, both the primary heat pipe 101 and the secondary heat pipe 102 are designed as upper and lower halves, that is: the heating section A1011, the condensing section A1012, the heating section B1021, and the condensing section B1022 are all designed as upper and lower halves. Among them, the upper and lower halves of the condensing section B1022 and the upper and lower halves of the heating section B1021 respectively form an integral topology heat pipe.

[0031] Furthermore, the upper and lower halves of the secondary heat pipe 102 can be designed as an integral ultra-thin flat plate heat pipe with an internal vacuum cavity structure containing a capillary wick and a heat pipe working medium.

[0032] Furthermore, the upper and lower halves of the secondary heat pipe 102 can be designed as a combined structure of an ultra-thin metal plate 201 and a pulsating heat pipe 202. For example... Figure 4 As shown, the outer surface of the pulsating heat pipe 202 is embedded in the inner surface of the ultrathin metal plate 201 and welded together. The thickness of the ultrathin metal plate 201 is 0.5–1.0 mm; the outer diameter of the pulsating heat pipe 202 is 2–4 mm.

[0033] In this embodiment, the secondary heat pipe 102 is a three-dimensional structure of a thin-shell circular sleeve, with each half of the secondary heat pipe 102 being a semi-circular sleeve thin-shell three-dimensional structure. The semi-circular sleeve structure, after being flattened along the axial direction and annular arc of the high-power motor of the UAV, becomes a rectangular ultra-thin flat shell, significantly increasing the heat exchange area for effective heat dissipation from the heat pipe to the surrounding atmosphere. The rectangular ultra-thin flat shell can be processed into a topological heat pipe sleeve using sheet metal thermoforming technology.

[0034] In this embodiment, the encapsulation metal materials of the primary heat pipe 101 and the secondary heat pipe 102 are copper alloy, aluminum alloy, or titanium alloy. The two-phase working medium of the primary heat pipe 101 and the secondary heat pipe 102 is a low-temperature fluid such as distilled water, ammonia, acetone, ethanol, or Freon. Both the primary heat pipe 101 and the secondary heat pipe 102 adopt a thin-shell design, and the weight of the entire heat sink does not exceed 100g.

[0035] In this embodiment, as Figure 5 As shown, the motor using the radiator described in this invention can eliminate the fins 1081 of the condenser section of the primary heat pipe, the fins 1082 on the motor housing, and the fan 109 arranged inside or at the rear end of the motor, which are not required in traditional heat pipe cooling schemes.

[0036] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0037] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A lightweight topological heat pipe sleeve thin-shell radiator for a high specific power motor of an unmanned aerial vehicle, characterized in that, include: Primary heat pipe (101) and secondary heat pipe (102); The high-power motor of the UAV uses a lightweight topological heat pipe sleeve thin-shell heat sink based on a primary heat pipe (101) and a secondary heat pipe (102) to dissipate heat from the high-power motor of the UAV; the high-power motor of the UAV operates in the near-space atmospheric environment; The high power-to-weight ratio motor for UAVs includes: an inner stator (103), an outer rotor (104), a motor shaft (105), and a motor housing (106); wherein the inner stator (103) and the outer rotor (104) are disposed within the motor housing (106); the inner stator (103) is located within the outer rotor (104); the rotation of the outer rotor (104) drives the motor shaft (105) to rotate, thereby driving the rotation of the UAV propeller (107); The primary heat pipe (101) includes a heating section A (1011) and a condensing section A (1012) that are smoothly connected; the secondary heat pipe (102) includes a heating section B (1021) and a condensing section B (1022) that are smoothly connected; wherein, the heating section A (1011) is in contact with the inner stator (103) and absorbs the heat generated by the inner stator coil in the form of thermal conduction; the heating section B (1021) is in contact with the condensing section A (1012) and absorbs the heat transferred by the primary heat pipe (101) in the form of thermal conduction; the condensing section B (1022) extends along the envelope of the motor housing (106) in a biomimetic topology, that is, it first bends outward from the tail end of the motor housing (106) and then bends along the axis of the high specific power motor of the UAV to extend towards the front end of the motor housing (106); The primary heat pipe (101) is arranged in a multi-ring pattern; the heating section A (1011) is designed as a cylindrical heat pipe that penetrates into the inner stator (103), or is closely attached to the circumferential outer surface of the inner stator (103), or is closely attached to the rear outer surface of the inner stator (103); the outer surface of the condensing section A (1012) is embedded in the inner surface of the heating section B (1021), and is fixed together by welding or riveting. Both the primary heat pipe (101) and the secondary heat pipe (102) are designed as upper and lower halves, that is, the heating section A (1011), the condensing section A (1012), the heating section B (1021) and the condensing section B (1022) are designed as upper and lower halves; among them, the upper and lower halves of the condensing section B (1022) and the upper and lower halves of the heating section B (1021) are respectively combined into an integral topology heat pipe; the upper and lower halves of the secondary heat pipe (102) are respectively designed as an integral ultra-thin flat plate heat pipe with a vacuum cavity structure inside, and a capillary wick and a heat pipe working medium are arranged.

2. The lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs according to claim 1, characterized in that, The upper and lower halves of the secondary heat pipe (102) are designed as a combination structure of an ultra-thin metal plate (201) and a pulsating heat pipe (202); wherein, the outer surface of the pulsating heat pipe (202) is embedded in the inner surface of the ultra-thin metal plate (201) and welded together; the thickness of the ultra-thin metal plate (201) is 0.5~1.0mm.

3. The lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs according to claim 2, characterized in that, The outer diameter of the pulsating heat pipe (202) is 2~4mm.

4. The lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs according to claim 1, characterized in that, The secondary heat pipe (102) is a three-dimensional structure with a thin-shell circular sleeve. The upper and lower halves of the secondary heat pipe (102) are each a thin-shell circular sleeve three-dimensional structure.

5. The lightweight topological heat pipe sleeve thin-shell radiator for high specific power motors of UAVs according to claim 1, characterized in that, The encapsulation metal of the primary heat pipe (101) and the secondary heat pipe (102) is made of copper alloy, aluminum alloy or titanium alloy; the two-phase working medium of the primary heat pipe (101) and the secondary heat pipe (102) is distilled water, ammonia, acetone, ethanol or Freon; the weight of the entire heat sink does not exceed 100g.

Images