Aircraft power system, aircraft power system heat dissipation method and unmanned aerial vehicle

Abstract

The invention discloses an aircraft power system, an aircraft power system heat dissipation method and an unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicle heat dissipation, the aircraft power system comprises a power cabin, paddles and fan blades, a driving device is arranged in the power cabin, and the driving device is in power connection with a paddle shaft; the propeller shaft extends from the interior of the power cabin body to the exterior of the power cabin body; the paddle is connected to the position, away from the driving device, of the paddle shaft, and the paddle is located outside the power cabin; the fan blades are connected to the positions, close to the driving device, of the propeller shaft, located in the power cabin and located between the driving device and the propeller blades. The fan blades are arranged between the paddles and the driving device, the driving device is used for driving the fan blades to rotate, air flow in the power cabin body is improved, and then effective heat dissipation of the driving device is achieved on the basis that the power cabin body is not changed.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of unmanned aerial vehicles, and in particular to an aircraft power system, an aircraft power system heat dissipation method and an unmanned aerial vehicle. Background Art

[0002] In the field of flying equipment, especially UAVs, the rapid development of UAV technology has promoted its widespread application in multiple industries, including but not limited to aerial photography, environmental monitoring, agricultural plant protection, logistics and distribution, etc. As the performance requirements of UAVs continue to increase, the stability and efficiency of their power systems have become one of the key factors restricting the development of UAVs. As the "heart" of the UAV, the power system will generate a lot of heat under long-term and high-intensity working conditions. If it cannot be dissipated in a timely and effective manner, it will not only lead to a decline in the performance of the power system, but also may cause serious safety problems, such as motor overheating and damage, battery short circuit, etc.

[0003] In order to solve the problem of power system overheating, the existing technology generally adopts the measures to adjust the structural design of the power nacelle (i.e., the nacelle that accommodates the engine, motor and related components). Specifically, heat dissipation holes or vents are opened on the surface of the power nacelle to increase the exposed area of ​​the heat-generating components, promote air circulation, and thus improve the heat dissipation efficiency. This design alleviates the problem of power system overheating to a certain extent, but it also brings new problems: the introduction of heat dissipation holes or vents destroys the original smooth aerodynamic shape of the power nacelle and increases the air resistance during flight.

[0004] The increase in aerodynamic drag has a significant impact on the flight performance of drones. On the one hand, it will reduce the flight speed of drones and affect the efficiency of mission execution; on the other hand, in order to overcome the additional drag, drones need to consume more energy, which directly shortens the flight time of drones and limits their operating range and continuous operation capabilities.

[0005] Therefore, how to ensure effective heat dissipation of the power system while maintaining good aerodynamic performance of the power nacelle and reducing unnecessary drag losses has become a technical problem that needs to be urgently solved in the current UAV design field. Summary of the invention

[0006] The purpose of the present invention is to provide an aircraft power system, an aircraft power system heat dissipation method and an unmanned aerial vehicle, so as to solve the problems existing in the above-mentioned prior art. By arranging fan blades between the propeller blades and the driving device, the fan blades are driven to rotate by the driving device to improve the air flow inside the power cabin, thereby achieving effective heat dissipation of the driving device without changing the power cabin.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides an aircraft power system, comprising a power cabin, propeller blades and fan blades, wherein a driving device is arranged in the power cabin, and the driving device is dynamically connected to a propeller shaft, and the propeller shaft extends from the interior of the power cabin to the exterior of the power cabin; the propeller blades are connected to a position of the propeller shaft away from the driving device, and the propeller blades are located outside the power cabin; the fan blades are connected to a position of the propeller shaft close to the driving device, and the fan blades are located inside the power cabin, and the fan blades are located between the driving device and the propeller blades.

[0009] In one embodiment, a fairing is further included, wherein the fairing includes a fairing body and a fairing shell, the fairing body is fixedly mounted on the propeller shaft, and the middle portion of the blade is buckled between the fairing body and the fairing shell.

[0010] In one embodiment, the fan blade is installed on a side of the fairing body away from the blade, the fairing body is provided with a first air vent, and the fairing shell is provided with a second air vent.

[0011] In one embodiment, the fairing body is connected to a hollow shaft segment, and the fan blades are evenly distributed and connected to the outer diameter side of the hollow shaft segment.

[0012] In one embodiment, the first ventilation holes are evenly distributed along the circumference of the fairing body, the second ventilation holes are evenly distributed along the circumference of the fairing main shell, and the second ventilation holes are arranged in a one-to-one correspondence with the first ventilation holes.

[0013] In one embodiment, the axial projection of the second ventilation hole falls within the axial projection range of the first ventilation hole.

[0014] In one embodiment, the driving device adopts a brushless motor, and the brushless motor is installed on the inner wall of the power cabin through a motor bracket. The interior of the brushless motor has an axially penetrating airflow channel.

[0015] In one embodiment, the motor bracket is provided with a third ventilation hole, and a gap is provided between the brushless motor and the inner wall of the power cabin.

[0016] The present invention provides a method for heat dissipation of an aircraft power system, which uses the aircraft power system as described above, and includes the following contents:

[0017] A fan blade is arranged between the blade and the driving device, and the fan blade is connected to the driving device in a power connection;

[0018] When the driving device drives the blades to rotate, the driving device synchronously drives the fan blades to rotate, so as to introduce the external airflow of the power cabin into the interior of the power cabin.

[0019] The present invention provides an unmanned aerial vehicle, comprising a fuselage and an aircraft power system as described above connected to the fuselage.

[0020] Compared with the prior art, the present invention has achieved the following technical effects:

[0021] The present invention arranges fan blades between the propeller blades and the driving device, and utilizes the driving device to drive the fan blades to rotate. There is no need to additionally arrange a power structure, so that the fan blades rotate together with the propeller shaft inside the power cabin, and utilizes the axially flowing airflow to blow air into the power cabin or accelerate the airflow, thereby improving the air flow inside the power cabin, thereby achieving effective heat dissipation of the driving device without changing the power cabin or destroying the aerodynamic shape of the power cabin, and can reduce the power cabin opening or reduce the damage to the aerodynamic shape caused by the leakage of heat-generating components, thereby achieving a perfect balance between the heat dissipation effect and the aerodynamic performance, thereby ensuring the efficient and stable flight of the aircraft and improving its comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the overall structure in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 Exploded structure diagram;

[0025] Figure 3 This is a schematic diagram of the connection between the drive device, the fan blades and the propeller blades in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the connection between the fairing body and the fan blades in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of a power cabin in an embodiment of the present invention;

[0028] Figure 6 Schematic diagram of a fairing shell in an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of the decomposition of the fairing body and the fairing shell in an embodiment of the present invention;

[0030] Figure 8 Computer simulation of internal airflow in the embodiment of the present invention Figure 1;

[0031] Fig. 9 Computer simulation of internal airflow in the embodiment of the present invention Figure 2 ;

[0032] Fig.10 Computer simulation of internal airflow in the embodiment of the present invention Figure 3 ;

[0033] Fig.11 Computer simulation of internal airflow in the embodiment of the present invention Figure 4 ;

[0034] Fig.12 is a comparison diagram of the drag coefficient (CD) and lift coefficient (CL) of the blade at different Reynolds numbers in an embodiment of the present invention;

[0035] Among them, 1. Power cabin; 2. Blades; 3. Fairing body; 4. Fairing shell; 5. Drive device; 6. Fan blades; 7. Hollow shaft section;

[0036] 31. The first ventilation hole;

[0037] 41. Second ventilation hole;

[0038] 51. propeller shaft; 52. motor bracket; 53. third ventilation hole. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The purpose of the present invention is to provide an aircraft power system, an aircraft power system heat dissipation method and an unmanned aerial vehicle to solve the problems existing in the prior art. By arranging fan blades between the propeller blades and the driving device, the fan blades are driven to rotate by the driving device to improve the air flow inside the power cabin, thereby achieving effective heat dissipation of the driving device without changing the power cabin.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1 to Figure 7As shown, the present invention provides an aircraft power system, including a power cabin 1, blades 2 and fan blades 6. A driving device 5 is arranged in the power cabin 1. The driving device 5 can be an engine or an electric motor. The driving device 5 is mainly used to provide a rotational driving force to the blades 2, so that the blades 2 provide lift for the aircraft. The driving device 5 is connected to a propeller shaft 51, which extends from the inside of the power cabin 1 to the outside of the power cabin 1 to facilitate the connection of the blades 2. The blades 2 are provided with at least two pieces, which are folded or unfolded. The blades 2 are connected to the propeller shaft 51 at a position away from the driving device 5, and the blades 2 are located outside the power cabin 1. The fan blades 6 are connected to the propeller shaft 51 at a position close to the driving device 5, and the fan blades 6 are located inside the power cabin 1. It should be noted that the distance between the fan blades 6 and the driving device 5 is not limited to being less than the distance between the fan blades 6 and the blades 2, that is, the fan blades 6 can be located between the driving device 5 and the blades 2. The fan blade 6 can be directly connected to the propeller shaft 51, or it can be installed on the shaft sleeve first, and then the shaft sleeve is used to connect with the propeller shaft 51. Therefore, the fan blade 6 is generally provided with multiple pieces, for example, three or more pieces are arranged in a circumferential distribution. The present invention provides an example of a six-piece arrangement (such as Figure 4 As shown). Since the fan blades 6 and the propeller blades 2 are both connected to the propeller shaft 51, under the action of the driving device 5, the fan blades 6 and the propeller blades 2 can rotate synchronously, so as to enhance the air flow inside the power cabin 1 when the aircraft power system is running, and realize the heat dissipation function. It is best to provide a channel connecting the inside and outside of the power cabin 1 around the propeller shaft 51 so that the external airflow can enter the inside of the power cabin 1. In addition, the deflection angle of the fan blades 6 makes the airflow flow toward the power cabin 1 the best, that is, when the fan blades 6 rotate, the external air can be driven into the power cabin 1. The specific structure of the fan blades 6 is not specifically limited, and any fan blades 6 of the axial flow type that can achieve the above-mentioned functions can be used.

[0043] The present invention arranges a fan blade 6 between the blade 2 and the driving device 5, and utilizes the driving device 5 to drive the fan blade 6 to rotate, without the need for an additional power structure, so that the fan blade 6 rotates together with the propeller shaft 51 inside the power cabin 1, and utilizes the axially flowing airflow to blow air into the power cabin 1 or accelerate the airflow, thereby improving the air flow inside the power cabin 1, and thus achieving effective heat dissipation of the driving device 5 without changing the power cabin 1 or destroying the aerodynamic shape of the power cabin 1, and can reduce the opening of the power cabin 1 or reduce the damage to the aerodynamic shape caused by the leakage of the heat-generating components, thereby achieving a perfect balance between the heat dissipation effect and the aerodynamic performance, thereby ensuring the efficient and stable flight of the aircraft and improving its comprehensive performance.

[0044] In one embodiment, if Figure 1-2 , Figure 5 to Figure 7As shown, the fairing also includes a fairing, which includes a fairing body 3 and a fairing shell 4. The fairing body 3 is fixedly mounted on the propeller shaft 51, and the fairing body 3 can rotate with the rotation of the propeller shaft 51. The fairing shell 4 can be installed on the fairing body 3 in a detachable manner such as bolts to achieve a fixed connection between the two, and the middle part of the blade 2 is buckled between the fairing body 3 and the fairing shell 4. The outer surface of the fairing is streamlined, which is conducive to reducing the force of wind on the power cabin 1, thereby reducing the resistance during flight. In addition, the fairing can also protect components such as the drive device 5 inside the power cabin 1, and prevent the high airflow generated during flight from causing damage to the drive device 5 and other components. Therefore, by setting the fairing and the fan blade 6, the large airflow of the blade 2 can be improved, so that the airflow entering the inside of the power cabin 1 is within a certain intensity range, and under the premise of ensuring heat dissipation, it is avoided to cause damage to components such as the drive device 5. It should be noted that the setting of the fairing should not hinder the air from entering the power cabin 1, and an air entry channel is retained between the fairing and the power cabin 1, or the fairing itself is provided with holes for air to enter the power cabin 1.

[0045] In one embodiment, if Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, the fan blade 6 is installed on the side of the fairing body 3 away from the blade 2, and can be directly installed on the fairing body 3, or installed on an additional structure such as a shaft sleeve. The fairing body 3 is provided with a first vent 31, and the fairing shell 4 is provided with a second vent 41. Under the drainage effect of the fan blade 6, the air outside the fairing first enters the inside of the fairing shell 4 through the second vent 41, and then enters the inside of the power cabin 1 through the first vent 31, and finally achieves the purpose of using external air to dissipate heat from the components such as the drive device 5 inside the power cabin 1.

[0046] In one embodiment, if Figure 4 As shown, the fairing body 3 is connected to the hollow shaft section 7, and the fan blades 6 are evenly distributed and connected to the outer diameter side of the hollow shaft section 7. By adopting the above-mentioned setting method, on the one hand, it is convenient to install and fix the fan blades 6. On the other hand, the fan blades 6 and the fairing body 3 are isolated at a certain distance by utilizing the hollow shaft section 7 to ensure the circulation effect of the airflow.

[0047] In one embodiment, if Figure 4 and Figure 7As shown, in order to adapt to the contour of the fairing shell 4, the outer shape of the fairing body 3 is designed to be circular, the first air holes 31 are evenly distributed along the circumference of the fairing body 3, the second air holes 41 are evenly distributed along the circumference of the fairing shell 4, and the second air holes 41 are arranged one by one with the first air holes 31. Since the fairing body 3 and the fairing shell 4 are relatively fixed, the second air holes 41 and the first air holes 31 are relatively fixed. Therefore, when external air passes through the fairing, it can directly enter the interior of the power compartment 1 along the second air holes 41 and the first air holes 31 to reduce air resistance.

[0048] In one embodiment, in combination Figure 7 As shown, the axial projection of the second air hole 41 falls within the axial projection range of the first air hole 31, that is, in the axial flow path, the flow area of ​​the first air hole 31 is larger than the flow area of ​​the second air hole 41, so as to make the airflow entering the fairing shell 4 enter the power compartment 1 with less resistance as much as possible.

[0049] In one embodiment, if Figure 2 , Figure 3 and Figure 5 As shown, the drive device 5 adopts a brushless motor, which is mounted on the inner wall of the power cabin 1 through a motor bracket 52. The main function of the motor bracket 52 is to fix the position of the drive device 5 so that the drive device 5 can be stably installed and fixed. The interior of the brushless motor may have an axially penetrating airflow channel, which may be an airflow channel formed between the stator and the rotor, inside the stator, or inside the rotor, so that the airflow introduced by the rotation of the fan blades 6 can enter the interior of the brushless motor, thereby improving the heat dissipation effect of the brushless motor.

[0050] In one embodiment, if Figure 5 As shown, the motor bracket 52 is provided with a third ventilation hole 53, and the third ventilation hole 53 is used for the passage through the power cabin 1. There is a gap between the brushless motor and the inner wall of the power cabin 1. Therefore, when the fan blades 6 are running, the airflow can pass through the power cabin 1, flow out of the power cabin 1, and enter the fuselage connected to the power cabin 1. The smooth flow of the airflow can better achieve the heat dissipation of the power cabin 1.

[0051] like Figure 8 As shown, through CFD simulation, it can be seen that at a rotation speed of 2000 rpm, the 15 m / s airflow is accelerated to about 20 m / s to 25 m / s, which can effectively improve the heat dissipation capacity inside the power cabin 1.

[0052] like Fig. 9 As shown, through CFD simulation, it can be seen that the internal airflow velocity changes when the airflow velocity is 20m / s, and the maximum airflow can reach about 32m / s.

[0053] like Fig.10 As shown, through CFD simulation, it can be seen that when the external airflow velocity is 0, the internal airflow velocity changes, and the maximum airflow can reach about 36m / s.

[0054] like Fig.11 As shown, it is the internal airflow simulation in a stationary state. Through CFD simulation, it can be seen that the maximum airflow can reach 20m / s at a rotation speed of 6000rpm.

[0055] like Figure 1 to Figure 7 As shown, the present invention provides a method for heat dissipation of an aircraft power system, which uses the aircraft power system as described above, and includes the following contents:

[0056] A fan blade 6 is arranged between the blade 2 and the driving device 5, and the fan blade 6 is connected to the driving device 5 in a power manner. The driving device 5 can drive the blade 2 to rotate, and can also drive the fan blade 6 to rotate;

[0057] When the driving device 5 drives the blades 2 to rotate, the driving device 5 synchronously drives the fan blades 6 to rotate, introducing the external airflow of the power cabin 1 into the interior of the power cabin 1, thereby achieving effective heat dissipation of the driving device 5 and other components in the power cabin 1.

[0058] The present invention provides an unmanned aerial vehicle, including a fuselage and an aircraft power system as described above connected to the fuselage, wherein a power cabin 1 is installed on the fuselage, and the rotation of blades 2 is used to drive the fuselage to achieve a flight state. At the same time, when the blades 2 are working, the fan blades 6 operate synchronously to achieve effective heat dissipation of the driving device 5.

[0059] In one embodiment, if Fig.12 As shown, the outer airfoil of blade 2 is FX-63-120, with an installation angle of 10 degrees, a root angle of 50 degrees, and a smooth transition of the overall angle. This airfoil has a high lift coefficient at a Reynolds number of 30,000. This airfoil is used as the main airfoil on the outer side of the airfoil, and a thickened non-standard airfoil is used at the root to improve the structural strength of the root in consideration of the structural strength problem.

[0060] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An aircraft power system, characterized in that: include: A power cabin, wherein a driving device is disposed in the power cabin, wherein the driving device is dynamically connected to a propeller shaft, and the propeller shaft extends from the inside of the power cabin to the outside of the power cabin; A propeller blade, the propeller blade is connected to a position of the propeller shaft away from the driving device, and the propeller blade is located outside the power cabin; And a fan blade, wherein the fan blade is connected to the propeller shaft at a position close to the driving device, the fan blade is located inside the power cabin, and the fan blade is located between the driving device and the propeller blade.

2. The aircraft power system according to claim 1, characterized in that: It also includes a fairing, which includes a fairing body and a fairing shell. The fairing body is fixedly installed on the propeller shaft, and the middle part of the blade is buckled between the fairing body and the fairing shell.

3. The aircraft power system according to claim 2, characterized in that: The fan blade is installed on a side of the fairing body away from the blade. The fairing body is provided with a first air vent, and the fairing shell is provided with a second air vent.

4. The aircraft power system according to claim 3, characterized in that: The fairing body is connected with a hollow shaft section, and the fan blades are evenly distributed and connected to the outer diameter side of the hollow shaft section.

5. The aircraft power system according to claim 3, characterized in that: The first ventilation holes are evenly distributed along the circumference of the fairing body, the second ventilation holes are evenly distributed along the circumference of the fairing shell, and the second ventilation holes are arranged in a one-to-one correspondence with the first ventilation holes.

6. The aircraft power system according to claim 5, characterized in that: The axial projection of the second ventilation hole falls within the axial projection range of the first ventilation hole.

7. The aircraft power system according to claim 1, characterized in that: The driving device adopts a brushless motor, and the brushless motor is installed on the inner wall of the power cabin through a motor bracket. The interior of the brushless motor has an axially penetrating air flow channel.

8. The aircraft power system according to claim 7, characterized in that: The motor bracket is provided with a third ventilation hole, and a gap is provided between the brushless motor and the inner wall of the power cabin.

9. A method for heat dissipation of an aircraft power system, characterized in that: The aircraft power system according to any one of claims 1 to 8 is applied, comprising the following contents: A fan blade is arranged between the blade and the driving device, and the fan blade is connected to the driving device in a power connection; When the driving device drives the blades to rotate, the driving device synchronously drives the fan blades to rotate, so as to introduce the external airflow of the power cabin into the interior of the power cabin.

10. A drone, characterized in that: The invention comprises a fuselage and an aircraft power system as claimed in any one of claims 1 to 8 connected to the fuselage.

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