Aircraft, blade, propeller, propulsion assembly, and movable platform

Abstract

An aircraft (100), blades (31), a propeller (30), a propulsion assembly, and a movable platform. The aircraft (100) comprises a fuselage (10), a structural member (20), and the propeller (30); the structural member (20) and the propeller (30) are provided on the fuselage (10); the propeller (30) comprises the blades (31); and the structural member (20) faces a pressure surface (S1) of each blade (31). Each blade (31) comprises a blade root portion (311), a main body portion (312) and a blade tip portion (313), the main body portion (312) comprises a first end (A1) and a second end (A2), and the first end (A1) is connected to the blade root portion (311). The blade tip portion (313) comprises a third end (A3) and a fourth end (A4), and the third end (A3) is connected to the second end (A2). The blade tip portion (313) gradually approaches the structural member (20) in the direction from the third end (A3) to the fourth end (A4), and the main body portion (312) gradually moves away from the structural member (20) in the direction from the first end (A1) to the second end (A2).

Description

Aircraft, blade, propeller, propulsion assembly and movable platform TECHNICAL FIELD

[0001] The present application relates to the field of movable platforms, and in particular to an aircraft, a blade, a propeller, a propulsion assembly and a movable platform. BACKGROUND

[0002] Most current movable platforms with propellers are faced with the problem that the aerodynamic noise of the propeller exceeds the index, affecting the user experience. The traditional blade noise reduction design is usually achieved by reducing the rotation speed of the propeller. Reducing the rotation speed of the propeller can reduce the vortex intensity on the surface of the blade, thereby achieving the effect of noise reduction. However, the motor is the power source for the rotation of the blade. Reducing the rotation speed has certain negative effects, such as increasing the motor torque, reducing the motor efficiency, and excessive motor temperature rise, etc. Ultimately, it will reduce the force efficiency of the entire power system, affecting the mobility and safety of the movable platform.

[0003] SUMMARY

[0004] Therefore, the present application provides an aircraft, a blade, a propeller, a propulsion assembly and a movable platform.

[0005] The aircraft provided by the first aspect of the present application comprises:

[0006] a machine body;

[0007] a structural member arranged on the machine body; and

[0008] a propeller rotatably arranged on the machine body, the propeller comprising a blade, the blade being provided with a pressure surface and a suction surface opposite to the pressure surface, the structural member facing the pressure surface, wherein the blade comprises:

[0009] a blade root portion;

[0010] a main body portion comprising a first end and a second end opposite to the first end, the first end being connected to the blade root portion; and

[0011] a blade tip portion comprising a third end and a fourth end opposite to the third end, the third end being connected to the second end;

[0012] wherein the blade tip portion gradually approaches the structural member along the direction from the third end to the fourth end, so that the blade tip portion is inclined or curved towards the side where the pressure surface is located; and the main body portion gradually moves away from the structural member along the direction from the first end to the second end, so as to reduce or eliminate the interference between the blade and the structural member.

[0013] The blade provided by the second aspect of the present application comprises:

[0014] paddle root portion;

[0015] a body portion including a first end and a second end opposite the first end, the first end connected to the paddle root portion; and

[0016] a tip portion including a third end and a fourth end opposite the third end, the third end connected to the second end;

[0017] wherein the body portion is arranged in an upturned configuration along a direction from the first end to the second end, and the tip portion is arranged in a downturned configuration along a direction from the third end to the fourth end.

[0018] The third aspect of the present application provides a paddle, comprising a paddle root portion, a body portion and a tip portion connected in sequence; a highest point of an airfoil profile at an abutment between the body portion and the tip portion is a turning point, and the highest point is a point of the airfoil profile farthest from a pressure surface of the paddle;

[0019] a first connecting line between a center point of the paddle root portion and the turning point, a second connecting line between the turning point and an outermost end point of the tip portion, and a third connecting line between the center point of the paddle root portion and the outermost end point of the tip portion;

[0020] wherein the first connecting line gradually moves away from the third connecting line along a direction from the center point of the paddle root portion to the turning point, and the second connecting line gradually moves closer to the third connecting line along a direction from the turning point to the outermost end point of the tip portion.

[0021] The fourth aspect of the present application provides a propeller, comprising a propeller seat and a paddle connected to the propeller seat, the paddle comprising:

[0022] a paddle root portion connected to the propeller seat;

[0023] a body portion including a first end and a second end opposite the first end, the first end connected to the paddle root portion; and

[0024] a tip portion including a third end and a fourth end opposite the third end, the third end connected to the second end;

[0025] wherein the body portion is arranged in an upturned configuration along a direction from the first end to the second end, and the tip portion is arranged in a downturned configuration along a direction from the third end to the fourth end.

[0026] The propelling assembly of the fifth aspect of the present application comprises a torque output device and a propeller in driving connection with the torque output device, the propeller comprises a propeller base and a propeller blade in connection with the propeller base, the propeller blade comprises:

[0027] a propeller root part in connection with the propeller base;

[0028] a main body part comprising a first end and a second end opposite to the first end, the first end being in connection with the propeller root part; and

[0029] a propeller tip part comprising a third end and a fourth end opposite to the third end, the third end being in connection with the second end;

[0030] wherein the main body part is arranged in an upwardly-inverted manner along a direction from the first end to the second end, and the propeller tip part is arranged in a downwardly-inverted manner along a direction from the third end to the fourth end.

[0031] The movable platform of the sixth aspect of the present application comprises a machine body and a propeller arranged on the machine body, the propeller blade of the propeller comprises:

[0032] a propeller root part;

[0033] a main body part comprising a first end and a second end opposite to the first end, the first end being in connection with the propeller root part; and

[0034] a propeller tip part comprising a third end and a fourth end opposite to the third end, the third end being in connection with the second end;

[0035] wherein the main body part is arranged in an upwardly-inverted manner along a direction from the first end to the second end, and the propeller tip part is arranged in a downwardly-inverted manner along a direction from the third end to the fourth end.

[0036] As can be seen from the above technical solutions, the aircraft proposed in the first aspect of this application, by setting the blade tip to gradually approach the structural member along the direction from the third end to the fourth end, so that the blade tip is tilted or bent towards the side where the pressure surface is located, in this embodiment, the blade tip tilted or bent towards the side where the pressure surface is located will suppress the airflow to flow towards the side where the suction surface is located, thereby reducing the pressure difference between the suction surface and the pressure surface of the blade tip, moving the load of the blade towards the blade root, reducing the load of the blade tip, reducing the turbulent kinetic energy and vortex of the blade tip, and reducing the noise generated by the blade tip, thereby effectively reducing the noise generated when the blade rotates, and solving the problem of high noise during aircraft flight. In addition, by setting the main body to gradually move away from the structural member along the direction from the first end to the second end, the interference between the blade and the structural member can be reduced or eliminated, that is, the problem of interference between the blade and the structural member when the blade tip is tilted or bent towards the side where the pressure surface is located can be reduced or eliminated. Therefore, the blade design proposed in this application can simultaneously satisfy noise reduction function and structural constraints. Since it does not require reducing propeller speed to achieve noise reduction, it also avoids the problems of increasing motor torque, reducing motor efficiency, increasing motor temperature rise, and ultimately reducing the power efficiency of the entire power system. The aircraft proposed in this application has good flight performance and high safety performance. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 is a schematic diagram of the structure of an aircraft according to an embodiment of this application;

[0039] Figure 2 is a side view schematic diagram of a blade according to an embodiment of this application;

[0040] Figure 3 is a top view schematic diagram of a blade according to an embodiment of this application;

[0041] Figure 4 is a schematic diagram of the blade root structure according to an embodiment of this application;

[0042] Figure 5 is a schematic diagram of the blade tip structure according to an embodiment of this application;

[0043] Figure 6 is a schematic diagram of the blade structure according to another embodiment of this application;

[0044] Figure 7 is a schematic diagram of the blade structure proposed in another embodiment of this application. Detailed Implementation

[0045] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts are within the scope of the present application.

[0046] Most of the current mobile platforms with propellers are facing the problem of aerodynamic noise exceeding the index. The aerodynamic interference of the propeller blade is the main source of noise. The noise of the propeller blade is mainly caused by the vortex generated by the air on the surface of the propeller blade during the flow process. Among them, the vortex intensity at the propeller tip is the largest, which is the main concern of noise reduction design. When the traditional propeller rotates, most of the airflow at the propeller tip will flow from the lower surface (pressure surface) of the propeller tip to the upper surface (suction surface) of the propeller tip, forming a vortex, and forming a large turbulent energy and vorticity below the propeller tip, which is the main cause of noise.

[0047] The existing propeller noise reduction design is usually achieved by reducing the rotation speed of the propeller. Reducing the rotation speed can reduce the vortex intensity on the surface of the propeller blade to reduce noise. However, the motor is the power source for driving the rotation of the propeller blade. Reducing the rotation speed has certain negative effects, such as increasing the motor torque, reducing the motor efficiency, and excessively high motor temperature rise, which ultimately leads to the problem of force efficiency reduction of the entire power system, affecting the flight performance and safety of the aircraft.

[0048] In view of the problem that the mobile platform has aerodynamic noise exceeding the index, and the problem that the existing propeller noise reduction design increases the motor torque, reduces the motor efficiency, and excessively high motor temperature rise, which ultimately leads to the problem of force efficiency reduction of the entire power system. The embodiments of the present application propose a high-efficiency and reliable noise reduction method.

[0049] As shown in FIG. 1 and FIG. 2, the embodiment of the present application proposes an aircraft 100, which comprises a body 10, a structural member 20 and a propeller 30. The structural member 20 is arranged on the body 10, and the propeller 30 is rotatably arranged on the body 10. The propeller 30 comprises a blade 31, which is provided with a pressure surface S1 and a suction surface S2 opposite to the pressure surface S1, and the structural member 20 faces the pressure surface S1. The blade 31 comprises a root portion 311, a main body portion 312 and a tip portion 313. The main body portion 312 comprises a first end A1 and a second end A2 opposite to the first end A1, and the first end A1 is connected with the root portion 311. The tip portion 313 comprises a third end A3 and a fourth end A4 opposite to the third end A3, and the third end A3 is connected with the second end A2. Wherein, the tip portion 313 gradually approaches the structural member 20 along the direction from the third end A3 to the fourth end A4, so that the tip portion 313 is inclined or curved towards the side where the pressure surface S1 is located. The main body portion 312 gradually moves away from the structural member 20 along the direction from the first end A1 to the second end A2, so as to reduce or eliminate the interference between the blade 31 and the structural member 20.

[0050] Wherein, the "pressure surface S1" is a surface where the flow velocity decreases when the airflow passes through the blade, and the surface pressure is high. The "suction surface S2" is a surface where the flow velocity increases when the airflow passes through the blade, and the surface pressure is low. The "structural member 20 faces the pressure surface S1" can be that the structural member 20 is directly opposite to the pressure surface S1, or the structural member 20 is inclined at a certain angle relative to the pressure surface S1. The "first end A1, second end A2, third end A3 and fourth end A4" can be an end point or an end surface, which can be determined according to the actual structure of the blade 31.

[0051] The aircraft 100 provided in the embodiments of the present application is provided with the blade tip portion 313 gradually approaching the structural member 20 along the direction from the third end A3 to the fourth end A4, so that the blade tip portion 313 is inclined or curved toward the side where the pressure surface S1 is located. In this embodiment, the blade tip portion 313 inclined or curved toward the side where the pressure surface S1 is located can inhibit the airflow from flowing toward the side where the suction surface S2 is located, so that the pressure difference between the suction surface S2 and the pressure surface S1 of the blade tip portion 313 is reduced, the load of the blade tip portion 313 is moved toward the blade root portion 311, the load of the blade tip portion 313 is reduced, the turbulent kinetic energy and the vorticity of the blade tip portion 313 are reduced, and the noise generated by the blade tip portion 313 is reduced, so that the noise generated when the blade 31 rotates can be effectively reduced, and the problem of large noise when the aircraft 100 flies can be solved. In addition, the main body portion 312 is gradually away from the structural member 20 along the direction from the first end A1 to the second end A2, so that the interference between the blade 31 and the structural member 20 can be reduced or eliminated, that is, the problem that the blade tip portion 313 is inclined or curved toward the side where the pressure surface S1 is located and interferes with the structural member 20 can be reduced or eliminated. Therefore, the design scheme of the blade 31 provided in the embodiments of the present application can simultaneously satisfy the noise reduction function and the structural constraint, and since the noise reduction is not achieved by reducing the rotation speed of the propeller 30, the problems of increasing the motor torque, reducing the motor efficiency, increasing the motor temperature, and ultimately reducing the force efficiency of the entire power system do not exist, and the aircraft 100 provided in the embodiments of the present application has good flight performance and high safety performance.

[0052] In an optional embodiment, the propeller 30 is arranged at the top of the machine body 10, and in the hovering state of the aircraft 100, the disc plane of the propeller 30 is parallel to the horizontal plane. The "blade tip portion 313 is inclined or curved toward the side where the pressure surface S1 is located" specifically means that the blade tip portion 313 is inclined or curved downward, or in other words, the blade tip portion 313 is inclined or curved toward the ground. The "main body portion 312 is gradually away from the structural member 20 along the direction from the first end A1 to the second end A2" specifically means that the main body portion 312 is gradually lifted from the first end A1 to the second end A2, or in other words, the main body portion 312 is gradually away from the ground.

[0053] In another optional embodiment, the propeller 30 is arranged at the front of the machine body 10, and the disc plane of the propeller 30 is perpendicular to the roll axis of the aircraft 100. The "blade tip portion 313 is inclined or curved toward the side where the pressure surface S1 is located" specifically means that the blade tip portion 313 is inclined or curved toward the rear of the aircraft 100. The "main body portion 312 is gradually away from the structural member 20 along the direction from the first end A1 to the second end A2" specifically means that the main body portion 312 is gradually extended toward the front of the aircraft 100 from the first end A1 to the second end A2.

[0054] In some embodiments, the interference between the structural member 20 and the blade 31 can be mechanical interference and / or light blocking. Specifically, whether the interference between the blade 31 and the structural member 20 is mechanical interference or light blocking depends on the type of the structural member 20.

[0055] For example, in some embodiments, as shown in FIG. 1 and FIG. 2, the structural member 20 includes a detection device 21, and the main body portion 312 gradually moves away from the structural member 20 along the direction from the first end Al to the second end A2 to reduce or eliminate the blade 31 from entering the field of view of the detection device 21. Optionally, the detection device 21 includes at least one of a visual sensor, a laser radar sensor, and an infrared detector.

[0056] For another example, in some embodiments, as shown in FIG. 1 and FIG. 2, the structural member 20 includes an arm 22, and the propeller 30 is arranged on the arm 22, and the main body portion 312 gradually moves away from the structural member 20 along the direction from the first end Al to the second end A2 to avoid mechanical interference between the blade 31 and the arm 22. Further, when the arm 22 is provided with a protrusion 221, the protrusion 221 can be an antenna and will not interfere with the blade 31. It should be noted that the structural member can also be other components on the aircraft 100. In addition, due to the perspective problem of the drawing 1, the blade tip portion 313 of the blade 31 appears to be in contact with the body 10, but in fact the blade tip portion 313 is above the body 10 and has a certain distance therefrom, so that no interference occurs.

[0057] As shown in FIG. 2, in some embodiments, the axial distance difference between the fourth end A4 and the center point C of the blade root portion 311 is less than or equal to a preset difference, and the axial distance difference is along the direction of the rotation axis L of the propeller 30. It can be understood that when the aircraft 100 is in a normal hovering state, the axial distance difference between the fourth end A4 of the blade tip portion 313 and the center point C of the blade root portion 311 represents the offset of the fourth end A4 of the blade tip portion 313 relative to the center point C of the blade root portion 311 in the vertical direction. The offset is within the preset difference, which reduces the space occupied by the blade in the vertical direction and facilitates storage. Moreover, since the blade tip and the blade root of most conventional blades are relatively flush, if the offset is too large, it will greatly affect the drag coefficient and the torque coefficient of the blade 31, causing the hovering working point of the aircraft 100 to change compared with conventional commonly used blades, which affects the performance of the whole machine. In the present embodiment, by controlling the axial distance difference within the preset difference, the noise reduction condition is met, and the increase of the drag coefficient and the torque coefficient of the blade 31 can be avoided, which will not greatly affect the hovering working point of the aircraft 100.

[0058] As shown in FIG. 3 and FIG. 4, in some embodiments, the blade root 311 of the blade 31 is provided with a connecting hole 314, through which the blade 31 is rotationally connected with the blade seat 32 of the propeller 30, facilitating the folding storage of the blade 31. The "center point C of the blade root 311" refers to the intersection point of the central surface D of the thickness direction of the blade root 311 and the center line E of the connecting hole 314.

[0059] Of course, the connection between the blade 31 and the blade seat 32 of the propeller 30 is not limited to be rotational connection, for example, in some other embodiments, the blade 31 can also be fixedly connected with the blade seat 32 of the propeller 30 through the connecting hole 314. In this embodiment, the "center point C of the blade root 311" also refers to the intersection point of the central surface D of the thickness direction of the blade root 311 and the center line E of the connecting hole 314.

[0060] It should be noted that the structure of the blade 31 is not limited to the above-mentioned embodiments, for example, in some other embodiments, the blade root 311 of the blade 31 can also not be provided with the connecting hole 314, and the "center point of the blade root 311" can be the geometric center point of the blade root 311.

[0061] In some embodiments, the preset difference is equal to or approximately equal to 10% of the radius of the blade 31.

[0062] In some embodiments, the axial distance difference is equal to or approximately equal to zero. In one embodiment, when the axial distance difference is equal to zero, the fourth end A4 of the blade tip 313 and the center point C of the blade root 311 are on the same horizontal line in the normal hovering state of the flying vehicle 100, that is, the blade tip 313 does not move downward relative to the blade root 311, does not interfere with the arm 22, and does not interfere with the detection device 21. Therefore, the blade 31 proposed in the present embodiment can be widely used in existing multicopter flying vehicles 100.

[0063] As shown in FIG. 2, in some embodiments, the main body part 312 is arranged in a positive up angle, the tip part 313 is arranged in a negative down angle, and the negative down angle of the tip part 313 is greater than the positive up angle of the main body part 312. The greater negative down angle is arranged to ensure the noise reduction effect. The test method of the positive up angle and the negative down angle can be performed according to the measurement rules of the person skilled in the art (for example, how to select the measurement point on the blade 31, etc.). For example, in some embodiments, the negative down angle can refer to the first line F1 between the highest point Y of the airfoil profile at the junction between the second end A2 of the main body part 312 and the third end A3 of the tip part 313 and the outermost end point W of the fourth end A4 of the tip part 313, relative to the spanwise direction of the blade 31. The positive up angle refers to the second line F2 between the highest point Y of the airfoil profile at the junction between the second end A2 of the main body part 312 and the third end A3 of the tip part 313 and the center point C of the hub part 311, relative to the spanwise direction of the blade 31. The "spanwise direction" refers to the direction in which the fourth end A4 of the tip part 313 points to the hub part 311 and is perpendicular to the rotation axis L of the propeller 30. It should be noted that the outermost end point W of the fourth end A4 is the end point of the tip part 313 farthest from the hub part 311. When the fourth end A4 is a point, the fourth end A4 can be the outermost end point W. When the fourth end A4 is a surface, the outermost end point W can be the center point of the fourth end A4.

[0064] As shown in FIG. 2, in some embodiments, the positive up angle of the main body part 312 is a, where a is 5°±2°. Alternatively, in some embodiments, the positive up angle of the main body part 312 is any one of 3°, 4°, 5°, 6°, 7°, or any value between any two adjacent values. In a preferred embodiment, the positive up angle of the main body part 312 is 5°. In the experimental verification process, it is known through the decoupling test of the positive up structure and the negative down structure of the blade 31 that the positive up structure causes the tension coefficient and the torque coefficient of the blade 31 to increase, the negative down structure causes the tension coefficient and the torque coefficient of the blade 31 to decrease, and both the positive up structure and the negative down structure cause the hovering working point of the aircraft 100 to change, affecting the performance of the whole machine. In this embodiment, by arranging the positive up angle of the main body part 312 to be 5°, the tension coefficient and the torque coefficient of the blade 31 can be prevented from increasing too much under the condition of reducing or eliminating the interference between the blade 31 and the structural member 20, so as to not have too great an influence on the hovering working point of the aircraft 100.

[0065] As shown in FIG. 2, in some embodiments, the lower reverse angle of the tip portion 313 is β, where β is 20° ± 5°. Alternatively, in some embodiments, the lower reverse angle of the tip portion 313 is any one of 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, or any value between any two adjacent values. In a preferred embodiment, the lower reverse angle of the tip portion 313 is 20°. It is found in the experimental verification process that the greater the lower reverse angle of the tip portion 313, the better the noise reduction effect that can be achieved, but the greater the lower reverse angle of the tip portion 313, the greater the interference of the tip portion 313 with the structural member 20. By setting the lower reverse angle of the tip portion 313 to 20°, both the noise reduction effect and the interference of the tip portion 313 with the structural member 20 can be taken into account.

[0066] It should be noted that the "upper reverse" and "lower reverse" described herein are professional terms in the field and do not represent "directional limitations". That is, the bending or tilting direction of the main body portion 312 and the tip portion 313 is not limited to the tilting or bending in the "up" and "down" directions in the actual space. When the disc plane of the propeller is perpendicular to the horizontal plane, the bending or tilting direction of the main body portion 312 and the tip portion 313 can also be tilting or bending in the "front" and "rear" directions.

[0067] As shown in FIG. 2, in some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is greater than the size of the tip portion 313 along the spanwise direction of the blade 31. The "spanwise direction" refers to the direction in which the fourth end A4 of the tip portion 313 points to the root portion 311 and is perpendicular to the rotation axis L of the propeller 30.

[0068] As shown in FIG. 2, in some embodiments, the size of the main body portion 312 along the length direction of the blade 31 is r, where r = (70%~90%)R, R is the size of the blade 31 along the length direction of the blade 31. Alternatively, in some embodiments, the size of the main body portion 312 along the length direction of the blade 31 is any one of 70%R, 71%R, 72%R, 73%R, 74%R, 75%R, 76%R, 77%R, 78%R, 79%R, 80%R, 81%R, 82%R, 83%R, 84%R, 85%R, 86%R, 87%R, 88%R, 89%R, 90%R, or any value between any two adjacent values. Further, the sum of the sizes of the blade root portion 311 and the main body portion 312 along the length direction of the blade 31 is equal to (74%~94%)R, R is the size of the blade 31 along the length direction of the blade 31. In one embodiment, the sum of the sizes of the blade root portion 311 and the main body portion 312 along the length direction of the blade 31 is 80%R. It should be noted that the structural features of the main body portion 312 upside and the blade tip portion 313 downside will affect the drag coefficient, torque coefficient and efficiency of the propeller 30, resulting in changes in the hovering speed, torque and power system force of the aerial vehicle, affecting the endurance time. It is found in the experimental verification process that by setting the size of the main body portion 312 along the length direction of the blade 31 to be (70%~90%)R, although the blade 31 is provided with the structural features of the main body portion 312 upside and the blade tip portion 313 downside, the drag coefficient, torque coefficient and efficiency of the propeller 30 do not change when the aerial vehicle 100 is hovering, that is, by setting the size of the main body portion 312 along the length direction of the blade 31 to be (70%~90%)R, although the structure of the blade 31 changes, the aerodynamic efficiency of the propeller 30 can still be maintained. It should be noted that since the aerodynamic efficiency of the propeller 30 can be maintained, the hovering endurance time of the aerial vehicle 100 is not lost, and there is no safety problem of the propeller 30 motor overheating. Further, the sum of the sizes of the blade root portion 311 and the main body portion 312 along the length direction of the blade 31 is equal to (74%~94%), and further, the sum of the sizes of the blade root portion 311 and the main body portion 312 along the length direction of the blade 31 is 80%R, so that the blade 31 can still maintain the aerodynamic efficiency of the propeller 30.

[0069] As shown in FIG. 5, in some embodiments, the vertical projection contour of the outer end portion 3131 of the blade tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 is a circular arc K1, that is, the outer end portion 3131 of the blade tip portion 313 is in the shape of a circular arc. In this embodiment, the chord length of the outermost end of the outer end portion 3131 can be minimized, and the vortex generated by the blade tip portion 313 when the blade 31 rotates is small, thereby playing a role in reducing noise. In addition, the circular arc-shaped blade tip portion 313 can also improve the safety of the blade and reduce friction with the outside.

[0070] The outermost end of the outer end portion 3131 refers to an end of the outer end portion 3131 farthest from the root portion 311, and the outermost end surface or the outermost end point W of the outer end portion 3131 is the fourth end A4. The "chord length" refers to the length of the cross section of the blade 31.

[0071] As shown in FIG. 5, in some embodiments, the radius of the circular arc K1 is d, where d is 2 mm ± 1 mm. Alternatively, in some embodiments, the radius of the circular arc K1 is any one of 1 mm, 2 mm, 3 mm, or any value between any two adjacent values. In a preferred embodiment, the radius of the circular arc K1 is 2 mm, which, by using this value, reduces the noise of the tip portion 313 while also reducing the difficulty of manufacturing the blade 31.

[0072] It should be noted that the vertical projection profile of the outer end portion 3131 of the tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 is not limited to being set as the circular arc K1 described above. For example, in another embodiment, as shown in FIG. 6, the vertical projection profile of the outer end portion 3131 of the tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 is a straight line K2, that is, the outer side surface of the outer end portion 3131 of the tip portion 313 is flat.

[0073] Of course, the vertical projection profile of the outer end portion 3131 of the tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 is not limited to being set as the circular arc K1 and the straight line K2 described above. For example, in another embodiment, as shown in FIG. 7, the vertical projection profile of the outer end portion 3131 of the tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 is a V-shaped K3, that is, the outer side surface of the outer end portion 3131 of the tip portion 313 is pointed.

[0074] As shown in FIG. 2 and FIG. 3, in some embodiments, the tip portion 313 is backward-swept. The blade 31 comprises a suction surface S2, a pressure surface S1, a leading edge S3 connecting one side of the suction surface S2 and the pressure surface S1, and a trailing edge S4 connecting the other side of the suction surface S2 and the pressure surface S1, and the "tip portion 313 is backward-swept" means that the leading edge S3 of the tip portion 313 is curved towards the trailing edge S4. By setting the tip portion 313 to be backward-swept, air resistance can be reduced, and pulling force and efficiency can be improved, so that the endurance distance of the aircraft 100 can be increased and the flight performance of the aircraft 100 can be improved. It should be noted that by setting the tip portion 313 to be backward-swept, the noise generated by the blade 31 when rotating can also be reduced, so that the aircraft 100 is more quiet when flying. Specifically, by setting the tip portion 313 to be backward-swept, the timing of air colliding with the main body portion 312 and colliding with the tip portion 313 is different, and the timing of colliding with the tip portion 313 is delayed relative to the timing of colliding with the main body portion 312, so that the noise generated by the main body portion 312 and the noise generated by the tip portion 313 are not at the same time, and do not superimpose, so that the amplitude of the noise can be reduced.

[0075] As shown in FIG. 3, in some embodiments, the backward-swept angle of the tip portion 313 is θ, where θ is 16°±5°. Alternatively, in some embodiments, the backward-swept angle of the tip portion 313 is any one of 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, or any value between any two adjacent values. In a preferred embodiment, the backward-swept angle of the tip portion 313 is 16°. It is found in the experimental verification process that by setting the backward-swept angle of the tip portion 313 to be 16°, the noise reduction effect and the convenience of storing the blade 31 can be considered at the same time.

[0076] The test method of the "backward-swept angle" can be performed according to the measurement rules of those skilled in the art (for example, how to select the measurement point on the blade 31, etc.). For example, in some embodiments, the "backward-swept angle" can refer to the included angle between the line M1 connecting the leading edge point of the third end A3 of the tip portion 313 and the leading edge point of the fourth end A4 of the tip portion 313, and the leading edge line M2 of the main body portion 312. In this embodiment, the leading edge line M2 of the main body portion 312 is a straight line.

[0077] It should be noted that, as described above, the vertical projection profile of the outer end 3131 of the tip portion 313 on a plane perpendicular to the rotation axis L of the propeller 30 can be circular arc-shaped, flat, and pointed. As shown in FIGS. 3 and 5, when the outer end 3131 of the tip portion 313 is circular arc-shaped, the leading edge point of the fourth end A4 of the tip portion 313 within the vertical projection profile on a plane perpendicular to the rotation axis L of the propeller 30 is the point farthest from the hub portion 311, i.e., the inflection point of the circular arc. As shown in FIG. 6, when the outer end 3131 of the tip portion 313 is flat, the leading edge point of the fourth end A4 of the tip portion 313 within the vertical projection profile on a plane perpendicular to the rotation axis L of the propeller 30 is the point where the flat outer end line connects with the leading edge S3. As shown in FIG. 7, when the tip portion 313 is pointed, the leading edge point of the fourth end A4 of the tip portion 313 within the vertical projection profile on a plane perpendicular to the rotation axis L of the propeller 30 is the pointed end point of the outer end 3131.

[0078] As shown in FIG. 1, in some embodiments, the propeller 30 includes a propeller base 32, and the number of the blades 31 is at least two. The at least two blades 31 are arranged at intervals on the propeller base 32 and rotatably connected with the propeller base 32. In this implementation, by arranging the blades 31 to be rotatably connected with the propeller base 32, when the aircraft 100 is completed, the blades 31 can be rotated and folded relative to the propeller base 32 to reduce the size of the aircraft 100, thereby facilitating the storage and carrying of the aircraft 100.

[0079] Of course, the blades 31 are not limited to being arranged to be rotatably connected with the propeller base 32. As described above, in some other embodiments, the blades 31 can also be arranged to be fixedly connected with the propeller base 32, which can be determined according to actual design needs.

[0080] In some embodiments, the hub portion 311, the main body portion 312, and the tip portion 313 are integrally connected. For example, in some embodiments, the hub portion 311, the main body portion 312, and the tip portion 313 are integrally injection molded.

[0081] The above-described embodiments describe the application of the blades 31 in the aircraft 100. It should be noted that the blades 31 are not limited to being used only in the aircraft 100, but can also be used in other movable platforms including the aircraft 100, which can be determined according to actual design needs.

[0082] As shown in FIGS. 2-7, the embodiment of the present application also proposes a paddle 31, which includes a paddle root part 311, a main body part 312, and a paddle tip part 313. The main body part 312 includes a first end A1 and a second end A2 opposite to the first end A1, and the first end A1 is connected with the paddle root part 311. The paddle tip part 313 includes a third end A3 and a fourth end A4 opposite to the third end A3, and the third end A3 is connected with the second end A2. Wherein, the main body part 312 is upwardly reversed along the direction from the first end A1 to the second end A2, and the paddle tip part 313 is downwardly reversed along the direction from the third end A3 to the fourth end A4.

[0083] The paddle 31 proposed by the embodiment can effectively reduce the noise generated when the paddle 31 rotates. Firstly, by setting the paddle tip part 313 to be downwardly reversed along the direction from the third end A3 to the fourth end A4, when the paddle 31 rotates, the downwardly reversed paddle tip part 313 can inhibit the airflow from flowing toward the side where the suction surface S2 is located, so that the pressure difference between the suction surface S2 and the pressure surface S1 of the paddle tip part 313 becomes smaller, the load of the paddle 31 moves toward the paddle root part 311, the load of the paddle tip part 313 becomes smaller, the turbulent kinetic energy and the vorticity of the paddle tip part 313 are reduced, and the noise generated by the paddle tip part 313 is smaller. Therefore, the noise generated when the paddle 31 rotates can be effectively reduced. Secondly, by setting the main body part 312 to be upwardly reversed along the direction from the first end A1 to the second end A2, when the paddle 31 is installed to the movable platform, the upwardly reversed main body part 312 can make the paddle tip part 313 gradually away from the structural member of the movable platform, so that the problem of the paddle tip part 313 interfering with the structural member of the movable platform can be reduced or eliminated. Therefore, the design scheme of the paddle 31 proposed by the embodiment of the present application can simultaneously satisfy the noise reduction function and the structural constraint of the movable platform, and can be widely applied to various existing movable platforms.

[0084] In some embodiments, the axial distance difference between the fourth end A4 and the center point C of the paddle root part 311 is less than or equal to a preset difference value, and the axial distance difference is the difference along the direction of the rotation axis L of the paddle 31.

[0085] In some embodiments, the preset difference value is equal to or approximately equal to 10% of the radius of the paddle 31.

[0086] In some embodiments, the axial distance difference is equal to or approximately equal to zero.

[0087] In some embodiments, the downwardly reversed angle of the paddle tip part 313 is greater than the upwardly reversed angle of the main body part 312.

[0088] In some embodiments, the upwardly reversed angle of the main body part 312 is a, wherein a is 5°±2°.

[0089] In some embodiments, the downwardly reversed angle of the paddle tip part 313 is β, wherein β is 20°±5°.

[0090] In some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is greater than the size of the tip portion 313 along the spanwise direction of the blade 31.

[0091] In some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is r, where r = (70%~90%)R, R is the size of the blade 31 along the spanwise direction of the blade 31.

[0092] In some embodiments, the tip portion 313 is backward-swept.

[0093] In some embodiments, the backward-swept angle of the tip portion 313 is θ, where θ is 16°±5°.

[0094] In some embodiments, the outer end portion 3131 of the tip portion 313 has a vertical projection profile on a plane perpendicular to the rotation axis of the blade root portion 311 as a circular arc K1.

[0095] In some embodiments, the radius of the circular arc K1 is d, where d is 2mm±1mm.

[0096] In some embodiments, the blade root portion 311, the main body portion 312, and the tip portion 313 are integrally connected.

[0097] The explanations, extensions, and benefits of the blade 31 structure according to the above embodiments can be referred to the above description, and will not be repeated here.

[0098] [Corrected according to Rule 91 on 19.11.2024] As shown in FIGS. 2-7, the embodiments of the present application also propose a blade 31, which comprises a blade root portion 311, a main body portion 312, and a tip portion 313 connected in sequence. The highest point Y of the airfoil profile at the joint between the main body portion 312 and the tip portion 313 is the inflection point O, which is the point farthest from the pressure surface S1 of the blade 31 of the airfoil profile of the blade 31. The airfoil profile is a professional term in the art, which refers to the cross section of the blade 31 in the direction from the leading edge to the trailing edge. The line connecting the center point C of the blade root portion 311 and the inflection point O is the first line P1, the line connecting the inflection point O and the outermost end point W of the tip portion 313 is the second line P2, and the line connecting the center point C of the blade root portion 311 and the outermost end point W of the tip portion 313 is the third line P3. Among them, the first line P1 gradually deviates from the third line P3 in the direction from the center point C of the blade root portion 311 to the inflection point O, and the second line P2 gradually approaches the third line P3 in the direction from the inflection point O to the outermost end point W of the tip portion 313.

[0099] In other words, as shown in FIG. 2, the center point C of the blade root 311, the inflection point O, and the outermost end point W of the blade tip 313 can be determined on the vertical projection of the blade 31 on the plane in which the rotation axis L of the propeller 30 intersects the span of the blade 31. Among them, the center point C of the blade root 311 is the center point of the outline of the blade root 311, the inflection point O is the highest point Y of the abutment between the main body 312 and the blade tip 313, and the outermost end point W of the blade tip 313 is the end point of the blade tip 313 farthest from the blade root 311.

[0100] The blade 31 proposed in this embodiment gradually approaches the third line P3 along the direction from the inflection point O to the outermost end point W of the blade tip 313 with respect to the second line P2, that is, the blade tip 313 is inclined or curved toward the side where the pressure surface S1 is located. In this embodiment, when the blade 31 rotates, the blade tip 313 inclined or curved toward the side where the pressure surface S1 is located can inhibit the airflow from flowing toward the side where the suction surface S2 is located, so that the pressure difference between the suction surface S2 and the pressure surface S1 of the blade tip 313 becomes smaller, the load of the blade 31 moves toward the blade root 311, the load of the blade tip 313 becomes smaller, the turbulent energy and the vorticity of the blade tip 313 are reduced, and the noise generated by the blade tip 313 is reduced, thereby effectively reducing the noise generated when the blade 31 rotates. Secondly, by setting the first line P1 gradually away from the third line P3 along the direction from the center point C of the blade root 311 to the inflection point O with respect to the third line P3, when the blade 31 is installed to the movable platform, the blade tip 313 can gradually move away from the structural member of the movable platform, and the problem of interference of the blade tip 313 with the structural member of the movable platform due to the inclination or curvature of the blade tip 313 toward the side where the pressure surface S1 is located can be reduced or eliminated. Therefore, the design scheme of the blade 31 proposed in this embodiment can simultaneously satisfy the noise reduction function and the structural constraint of the movable platform, and can be widely applied to various existing movable platforms.

[0101] In some embodiments, the axial distance difference between the outermost end point W of the blade tip 313 and the center point C of the blade root 311 is less than or equal to a preset difference value, and the axial distance difference is the difference along the rotation axis L of the blade 31.

[0102] In some embodiments, the preset difference value is equal to or approximately equal to 10% of the radius of the blade 31.

[0103] In some embodiments, the axial distance difference is equal to or approximately equal to zero.

[0104] In some embodiments, the inclination angle of the first line P1 with respect to the third line P3 is α, and the inclination angle of the second line P2 with respect to the third line P3 is β, wherein α and β are both acute angles, and α is less than β.

[0105] In some embodiments, a is 5°±2°.

[0106] In some embodiments, β is 20°±5°.

[0107] In some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is greater than the size of the tip portion 313 along the spanwise direction of the blade 31.

[0108] In some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is r, where r=(70%~90%)R, R is the size of the blade 31 along the spanwise direction of the blade 31.

[0109] In some embodiments, the tip portion 313 is backward-swept.

[0110] In some embodiments, the backward-swept angle of the tip portion 313 is θ, where θ is 16°±5°.

[0111] In some embodiments, the outer end portion 3131 of the tip portion 313 has a vertical projection profile on a plane perpendicular to the rotation axis of the hub portion 311 as a circular arc K1.

[0112] In some embodiments, the radius of the circular arc K1 is d, where d is 2mm±1mm.

[0113] In some embodiments, the hub portion 311, the main body portion 312, and the tip portion 313 are integrally connected.

[0114] The explanations, extensions, and benefits of the blade 31 structure of the above embodiments can refer to the above description, and will not be repeated here.

[0115] As shown in FIGS. 1-7, the embodiments of the present application also propose a propeller 30, which comprises a propeller hub 32 and a blade 31 connected to the propeller hub 32, the blade 31 comprising a hub portion 311, a main body portion 312, and a tip portion 313, the hub portion 311 being connected to the propeller hub 32, the main body portion 312 comprising a first end A1 and a second end A2 opposite to the first end A1, the first end A1 being connected to the hub portion 311, the tip portion 313 comprising a third end A3 and a fourth end A4 opposite to the third end A3, the third end A3 being connected to the second end A2. Wherein, the main body portion 312 is upwardly inclined along the direction from the first end A1 to the second end A2, and the tip portion 313 is downwardly inclined along the direction from the third end A3 to the fourth end A4.

[0116] Wherein, the first end A1, the second end A2, the third end A3, and the fourth end A4 can be an end point or an end face, which can be determined according to the actual structure of the blade 31.

[0117] The propeller 30 proposed in the embodiment is provided with the downwardly-inverted prop tip 313 of the blade 31 along the direction from the third end A3 to the fourth end A4. When the propeller 30 rotates, the downwardly-inverted prop tip 313 can inhibit the airflow from flowing toward the side where the suction surface S2 is located, so that the pressure difference between the suction surface S2 and the pressure surface S1 of the prop tip 313 is reduced, the load of the blade 31 is moved toward the root 311, the load of the prop tip 313 is reduced, the turbulent kinetic energy and the vorticity of the prop tip 313 are reduced, and the noise generated by the prop tip 313 is reduced, thereby effectively reducing the noise generated when the blade 31 rotates. In addition, the main body 312 is provided with the upwardly-inverted main body 312 along the direction from the first end A1 to the second end A2. When the propeller 30 is installed on the movable platform, the upwardly-inverted main body 312 can make the prop tip 313 gradually away from the structural member of the movable platform, thereby reducing or eliminating the interference problem of the prop tip 313 with the structural member of the movable platform. Therefore, the propeller 30 proposed in the embodiment can simultaneously satisfy the noise reduction function and the structural constraint of the movable platform, and can be widely applied to various existing movable platforms.

[0118] In some embodiments, the axial distance difference between the fourth end A4 and the center point C of the root 311 is less than or equal to a preset difference value, and the axial distance difference is the difference along the direction of the rotation axis L of the blade 31.

[0119] In some embodiments, the preset difference value is equal to or approximately equal to 10% of the radius of the blade 31.

[0120] In some embodiments, the axial distance difference is equal to or approximately equal to zero.

[0121] In some embodiments, the downwardly-inverted angle of the prop tip 313 is greater than the upwardly-inverted angle of the main body 312.

[0122] In some embodiments, the upwardly-inverted angle of the main body 312 is α, and α is 5°±2°.

[0123] In some embodiments, the downwardly-inverted angle of the prop tip 313 is β, and β is 20°±5°.

[0124] In some embodiments, the size of the main body 312 along the spanwise direction of the blade 31 is greater than the size of the prop tip 313 along the spanwise direction of the blade 31.

[0125] In some embodiments, the size of the main body 312 along the spanwise direction of the blade 31 is r, and r=(70%~90%)R, where R is the size of the blade 31 along the spanwise direction of the blade 31.

[0126] In some embodiments, the prop tip 313 is in a backward-swept shape.

[0127] In some embodiments, the sweepback angle of the tip portion 313 is θ, where θ is 16°±5°.

[0128] In some embodiments, the outer end portion 3131 of the tip portion 313 has a vertical projection profile on a plane perpendicular to the rotation axis of the root portion 311 as a circular arc K1.

[0129] In some embodiments, the radius of the circular arc K1 is d, where d is 2mm±1mm.

[0130] In some embodiments, the root portion 311, the main body portion 312 and the tip portion 313 are integrally connected.

[0131] The above-mentioned explanations, expansions and benefits of the blade 31 structure according to the embodiments can refer to the above description, and will not be repeated here.

[0132] As shown in FIGS. 1-7, the embodiments of the present application also provide a propelling device, which comprises a torque output device 40 and a propeller 30 in driving connection with the torque output device 40. The propeller 30 comprises a propeller base 32 and a blade 31 connected with the propeller base 32. The blade 31 comprises a root portion 311, a main body portion 312 and a tip portion 313. The root portion 311 is connected with the propeller base 32. The main body portion 312 comprises a first end A1 and a second end A2 opposite to the first end A1. The first end A1 is connected with the root portion 311. The tip portion 313 comprises a third end A3 and a fourth end A4 opposite to the third end A3. The third end A3 is connected with the second end A2. Wherein, the main body portion 312 is upwardly inclined along the direction from the first end A1 to the second end A2, and the tip portion 313 is downwardly inclined along the direction from the third end A3 to the fourth end A4.

[0133] Wherein, the torque output device 40 can comprise a motor. The first end A1, the second end A2, the third end A3 and the fourth end A4 can be an end point or an end face, which can be determined according to the actual structure of the blade 31.

[0134] The propelling device provided in the embodiment can effectively reduce the noise generated when the propeller 31 rotates. Firstly, the propeller 31 is arranged in the reverse direction along the third end A3 to the fourth end A4, and the propeller 31 is arranged in the reverse direction along the first end A1 to the second end A2. When the propelling device is installed on the movable platform, the propeller 31 can gradually move away from the structural member of the movable platform, thereby reducing or eliminating the interference of the propeller 31 with the structural member of the movable platform. Therefore, the propelling device provided in the embodiment can simultaneously satisfy the noise reduction function and the structural constraint of the movable platform, and can be widely applied to various movable platforms.

[0135] In some embodiments, the axial distance difference between the fourth end A4 and the center point C of the blade root 311 is less than or equal to a preset difference value, and the axial distance difference is the difference along the rotation axis L of the propeller 31.

[0136] In some embodiments, the preset difference value is equal to or approximately equal to 10% of the radius of the propeller 31.

[0137] In some embodiments, the axial distance difference is equal to or approximately equal to zero.

[0138] In some embodiments, the reverse angle of the propeller tip 313 is greater than the reverse angle of the main body 312.

[0139] In some embodiments, the reverse angle of the main body 312 is α, and α is 5°±2°.

[0140] In some embodiments, the reverse angle of the propeller tip 313 is β, and β is 20°±5°.

[0141] In some embodiments, the size of the main body 312 along the span direction of the propeller 31 is greater than the size of the propeller tip 313 along the span direction of the propeller 31.

[0142] In some embodiments, the size of the main body 312 along the span direction of the propeller 31 is r, and r=(70%~90%)R, R is the size of the propeller 31 along the span direction of the propeller 31.

[0143] In some embodiments, the propeller tip 313 is arranged in a backward-swept manner.

[0144] In some embodiments, the sweepback angle of the tip portion 313 is θ, where θ is 16°±5°.

[0145] In some embodiments, the outer end portion 3131 of the tip portion 313 has a vertical projection profile on a plane perpendicular to the rotation axis of the root portion 311 as a circular arc K1.

[0146] In some embodiments, the radius of the circular arc K1 is d, where d is 2mm±1mm.

[0147] In some embodiments, the root portion 311, the main body portion 312 and the tip portion 313 are integrally connected.

[0148] The explanation, expansion and benefits of the blade 31 structure of the above embodiments can refer to the description above, which will not be repeated here.

[0149] As shown in FIGS. 1-7, the embodiments of the present application also propose a movable platform, which comprises a body 10 and a propeller 30 arranged on the body 10. The blade 31 of the propeller 30 comprises a root portion 311, a main body portion 312 and a tip portion 313. The main body portion 312 comprises a first end A1 and a second end A2 opposite to the first end A1. The first end A1 is connected to the root portion 311. The tip portion 313 comprises a third end A3 and a fourth end A4 opposite to the third end A3. The third end A3 is connected to the second end A2. The main body portion 312 is arranged upwardly along the direction from the first end A1 to the second end A2. The tip portion 313 is arranged downwardly along the direction from the third end A3 to the fourth end A4.

[0150] The first end A1, the second end A2, the third end A3 and the fourth end A4 can be an end point or an end face, which can be determined according to the actual structure of the blade 31.

[0151] The movable platform proposed by the embodiments of the present application has the following advantages. The tip portion 313 is arranged downwardly along the direction from the third end A3 to the fourth end A4. When the blade 31 rotates, the downwardly arranged tip portion 313 can inhibit the airflow from flowing towards the side where the suction surface S2 is located. The pressure difference between the suction surface S2 and the pressure surface S1 of the tip portion 313 is reduced. The load of the blade 31 moves towards the root portion 311. The load of the tip portion 313 is reduced. The turbulent kinetic energy and the vorticity of the tip portion 313 are reduced. The noise generated by the tip portion 313 is reduced. Thus, the noise generated by the rotation of the blade 31 can be effectively reduced. In addition, the main body portion 312 is arranged upwardly along the direction from the first end A1 to the second end A2. The upwardly arranged main body portion 312 can make the tip portion 313 gradually away from the structural member of the movable platform. Thus, the interference problem of the tip portion 313 with the structural member of the movable platform can be reduced or eliminated.

[0152] In some embodiments, the blade 31 is provided with a pressure surface S1 and a suction surface S2 opposite to the pressure surface S1, and the movable platform further comprises a structural member 20 provided on the body 10, the structural member 20 faces the pressure surface S1, and the main body portion 312 is arranged in a reverse manner along the direction from the first end A1 to the second end A2, so as to reduce or eliminate the interference between the blade 31 and the structural member 20.

[0153] In some embodiments, the structural member 20 comprises a detection device 21, and the main body portion 312 gradually moves away from the structural member 20 along the direction from the first end A1 to the second end A2, so as to reduce or eliminate the blade 31 from entering the field of view angle of the detection device 21.

[0154] In some embodiments, the detection device 21 comprises at least one of a visual sensor, a laser radar sensor, and an infrared detector.

[0155] In other embodiments, the structural member 20 comprises a robot arm 22, and the propeller 30 is provided on the robot arm 22, and the main body portion 312 gradually moves away from the structural member 20 along the direction from the first end A1 to the second end A2, so as to avoid mechanical interference between the blade 31 and the robot arm 22. It should be noted that the structural member 20 can also be other components on the movable platform.

[0156] In some embodiments, an axial distance difference between the fourth end A4 and the center point C of the blade root portion 311 is less than or equal to a preset difference value, and the axial distance difference is a difference along the direction of the rotation axis L of the propeller 30.

[0157] In some embodiments, the preset difference value is equal to or approximately equal to 10% of the radius of the blade 31.

[0158] In some embodiments, the axial distance difference is equal to or approximately equal to zero.

[0159] In some embodiments, the main body portion 312 is arranged in a reverse manner, and the blade tip portion 313 is arranged in a reverse manner, and the reverse angle of the blade tip portion 313 is greater than the reverse angle of the main body portion 312.

[0160] In some embodiments, the reverse angle of the main body portion 312 is α, and α is 5°±2°.

[0161] In some embodiments, the reverse angle of the blade tip portion 313 is β, and β is 20°±5°.

[0162] In some embodiments, the size of the main body portion 312 along the spanwise direction of the blade 31 is greater than the size of the blade tip portion 313 along the spanwise direction of the blade 31.

[0163] In some embodiments, the root portion 311 and the body portion 312 have a dimension along the span of the blade 31 of r, where r = (70%~90%)R, and R is a dimension of the blade 31 along the span of the blade 31.

[0164] In some embodiments, the tip portion 313 is backward-swept.

[0165] In some embodiments, the tip portion 313 has a backward-swept angle of θ, where θ is 16°±5°.

[0166] In some embodiments, the outer end portion 3131 of the tip portion 313 has a vertical projection profile on a plane perpendicular to the rotation axis L of the propeller 30 as a circular arc K1.

[0167] In some embodiments, the circular arc K1 has a radius of d, where d is 2mm±1mm.

[0168] In some embodiments, the interference between the structural member 20 and the blade 31 includes at least one of the following: mechanical interference or light blocking.

[0169] In some embodiments, the propeller 30 includes a hub 32, and the number of blades 31 is at least two, and the at least two blades 31 are arranged at intervals on the hub 32 and are rotatably connected to the hub 32.

[0170] In some embodiments, the root portion 311, the body portion 312, and the tip portion 313 are integrally connected.

[0171] In some embodiments, the movable platform includes an aircraft, a ground moving device, an underwater moving device, an air conditioning device, etc.

[0172] The explanations, extensions, and benefits of the blade 31 structure according to the above embodiments can be referred to the above description, and will not be repeated here.

[0173] The above description is merely specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any modifications or replacements within the technical scope disclosed by the present application can be easily thought by those skilled in the art, and these modifications or replacements shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An aircraft, characterized in that The utility model relates to a propeller, comprising: a body; a structural member disposed on the body; and a propeller rotatably disposed on the body, the propeller comprising a blade having a pressure surface and a suction surface opposite to the pressure surface, the structural member facing the pressure surface, wherein the blade comprises: a blade root portion; a main body portion comprising a first end connected to the blade root portion and a second end opposite to the first end; and a blade tip portion comprising a third end connected to the second end and a fourth end opposite to the third end; wherein the blade tip portion gradually approaches the structural member along a direction from the third end to the fourth end, such that the blade tip portion is inclined or curved towards a side where the pressure surface is located; and the main body portion gradually moves away from the structural member along a direction from the first end to the second end, so as to reduce or eliminate an interference between the blade and the structural member.

2. The aircraft of claim 1, wherein, An axial distance difference between the fourth end and a center point of the blade root portion is less than or equal to a preset difference, the axial distance difference being a difference along a direction of an axis of rotation of the propeller.

3. The aircraft of claim 2, wherein, The preset difference is equal to or approximately equal to 10% of a radius of the blade.

4. The aircraft of claim 2 or 3, wherein, The axial distance difference is equal to or approximately equal to zero.

5. The aircraft of any one of claims 1 to 4, wherein, The main body portion is arranged in an upwardly concave manner, and the blade tip portion is arranged in a downwardly concave manner, a downwardly concave angle of the blade tip portion being greater than an upwardly concave angle of the main body portion.

6. The aircraft of claim 5, wherein, The upwardly concave angle of the main body portion is alpha, wherein alpha is 5°±2°.

7. The aircraft of claim 5, wherein, The downwardly concave angle of the blade tip portion is beta, wherein beta is 20°±5°.

8. The aircraft of any one of claims 1 to 7, wherein, A dimension of the main body portion along a spanwise direction of the blade is greater than a dimension of the blade tip portion along the spanwise direction of the blade.

9. The aircraft of claim 8, wherein, The dimension of the main body portion along the spanwise direction of the blade is r, wherein r=(70%~90%)R, and R is a dimension of the blade along the spanwise direction of the blade.

10. The aircraft of any one of claims 1 to 9, wherein, The blade tip portion is arranged in a backward-swept manner.

11. The aircraft of claim 10, wherein, A backward-swept angle of the blade tip portion is theta, wherein theta is 16°±5°.

12. The aircraft of any one of claims 1 to 11, wherein, An outer end portion of the blade tip portion has a vertical projection contour on a plane perpendicular to an axis of rotation of the propeller in a circular arc shape.

13. The aircraft of claim 12, wherein, A radius of the circular arc is d, wherein d is 2mm±1mm.

14. The aircraft of any one of claims 1 to 13, wherein, An interference between the structural member and the blade includes at least one of a mechanical interference or a light blocking.

15. The aircraft of claim 14, wherein, The structural member comprises a detection device, and the main body portion gradually moves away from the structural member along a direction from the first end to the second end, so as to reduce or eliminate the blade from entering a field of view of the detection device.

16. The aircraft of claim 15, wherein, The detection device comprises at least one of: a visual sensor, a laser radar sensor, or an infrared detector.

17. The aircraft of claim 14, wherein, The structural member comprises an arm, the propeller is disposed on the arm, and the main body portion gradually moves away from the structural member along a direction from the first end to the second end, so as to avoid a mechanical interference between the blade and the arm.

18. The aircraft of any one of claims 1 to 17, wherein, The propeller comprises a hub, and the number of the blades is at least two, the at least two blades being spaced apart and rotatably connected to the hub.

19. The aircraft of any one of claims 1 to 18, wherein, The blade root portion, the main body portion, and the blade tip portion are integrally connected.

20. A paddle, characterized by The utility model relates to a propeller, comprising: a blade root portion; a body portion comprising a first end and a second end opposite to the first end, the first end being connected with the blade root portion; and a tip portion comprising a third end and a fourth end opposite to the third end, the third end being connected with the second end; wherein the body portion is upward-cambered along a direction from the first end to the second end, and the tip portion is downward-cambered along a direction from the third end to the fourth end.

21. The paddle of claim 20, wherein, an axial distance difference between the fourth end and a center point of the blade root portion is less than or equal to a preset difference value, the axial distance difference being a difference along a direction of a rotation axis of the blade.

22. The paddle of claim 21, wherein, the preset difference value is equal to or approximately equal to 10% of a radius of the blade.

23. The paddle of claim 21 or 22, wherein, the axial distance difference is equal to or approximately equal to zero.

24. The paddle of any one of claims 20 to 23, wherein, a downward-cambered angle of the tip portion is greater than an upward-cambered angle of the body portion.

25. The paddle of any one of claims 20 to 24, wherein, the upward-cambered angle of the body portion is α, wherein α is 5°±2°.

26. The paddle of any one of claims 20 to 24, wherein, the downward-cambered angle of the tip portion is β, wherein β is 20°±5°.

27. The paddle of any one of claims 20 to 26, wherein, a dimension of the body portion along a spanwise direction of the blade is greater than a dimension of the tip portion along the spanwise direction of the blade.

28. The paddle of claim 27, wherein, the dimension of the body portion along the spanwise direction of the blade is r, wherein r=(70%~90%)R, and the R is a dimension of the blade along the spanwise direction of the blade.

29. The paddle of any one of claims 20 to 28, wherein, the tip portion is backward-swept.

30. The paddle of claim 29, wherein, a backward-swept angle of the tip portion is θ, wherein θ is 16°±5°.

31. The paddle of any one of claims 20 to 30, wherein, a vertical projection contour of an outer end portion of the tip portion on a plane perpendicular to a rotation axis of the blade root portion is a circular arc.

32. The paddle of claim 31, wherein, a radius of the circular arc is d, wherein d is 2mm±1mm.

33. The paddle of any one of claims 20 to 32, wherein, the blade root portion, the body portion and the tip portion are integrally connected.

34. A paddle, characterized by comprising a blade root portion, a body portion and a tip portion connected in sequence; a highest point of an airfoil profile at an abutment between the body portion and the tip portion is a turning point, the highest point being a point of the airfoil profile farthest from a pressure surface of the blade; a line connecting a center point of the blade root portion and the turning point is a first line, a line connecting the turning point and an outermost end point of the tip portion is a second line, and a line connecting the center point of the blade root portion and the outermost end point of the tip portion is a third line; wherein the first line gradually moves away from the third line along a direction from the center point of the blade root portion to the turning point relative to the third line, and the second line gradually moves closer to the third line along a direction from the turning point to the outermost end point of the tip portion relative to the third line.

35. The paddle of claim 34, wherein, an axial distance difference between the outermost end point of the tip portion and the center point of the blade root portion is less than or equal to a preset difference value, the axial distance difference being a difference along a direction of a rotation axis of the blade.

36. The paddle of claim 35, wherein, the preset difference value is equal to or approximately equal to 10% of a radius of the blade.

37. The paddle of claim 35 or 36, wherein, the axial distance difference is equal to or approximately equal to zero.

38. The paddle of any one of claims 34 to 37, wherein, an inclination angle of the first line relative to the third line is α, and an inclination angle of the second line relative to the third line is β, wherein α and β are both acute angles, and α is less than β.

39. The paddle of claim 38, wherein, α is 5°±2°.

40. The paddle of claim 38, wherein, β is 20°±5°.

41. The paddle of any one of claims 34 to 40, wherein, The size of the main body part along the length direction of the blade is greater than the size of the tip part along the length direction of the blade.

42. The paddle of claim 41, wherein, The size of the main body part along the length direction of the blade is r, wherein r=(70%-90%)R, and R is the size of the blade along the length direction of the blade.

43. The paddle of any one of claims 34 to 42, wherein, The tip part is backward-swept.

44. The paddle of claim 43, wherein, The backward-swept angle of the tip part is θ, wherein θ is 16°±5°.

45. The paddle of any one of claims 34 to 44, wherein, The outer end of the tip part is a circular arc in a vertical projection profile on a plane perpendicular to the rotation axis of the root part.

46. The paddle of claim 45, wherein, The radius of the circular arc is d, wherein d is 2mm±1mm.

47. The paddle of any one of claims 34 to 46, wherein, The root part, the main body part and the tip part are integrally connected.

48. A propeller, characterized by The propeller comprises a propeller seat and a propeller blade connected to the propeller seat, the propeller blade comprising: a root part connected to the propeller seat; a main body part comprising a first end and a second end opposite to the first end, the first end being connected to the root part; and a tip part comprising a third end and a fourth end opposite to the third end, the third end being connected to the second end; wherein the main body part is upwardly reversed along the direction from the first end to the second end, and the tip part is downwardly reversed along the direction from the third end to the fourth end.

49. A propulsion device characterized by, The propeller comprises a propeller seat and a propeller blade connected to the propeller seat, the propeller blade comprising: a root part connected to the propeller seat; a main body part comprising a first end and a second end opposite to the first end, the first end being connected to the root part; and a tip part comprising a third end and a fourth end opposite to the third end, the third end being connected to the second end; wherein the main body part is upwardly reversed along the direction from the first end to the second end, and the tip part is downwardly reversed along the direction from the third end to the fourth end.

50. A movable platform, characterized by The propeller comprises a propeller seat and a propeller blade connected to the propeller seat, the propeller blade comprising: a root part connected to the propeller seat; a main body part comprising a first end and a second end opposite to the first end, the first end being connected to the root part; and a tip part comprising a third end and a fourth end opposite to the third end, the third end being connected to the second end; wherein the main body part is upwardly reversed along the direction from the first end to the second end, and the tip part is downwardly reversed along the direction from the third end to the fourth end.

51. The moveable platform of claim 50, wherein, The propeller comprises a propeller seat and a propeller blade connected to the propeller seat, the propeller blade comprising: a root part connected to the propeller seat; a main body part comprising a first end and a second end opposite to the first end, the first end being connected to the root part; and a tip part comprising a third end and a fourth end opposite to the third end, the third end being connected to the second end; wherein the main body part is upwardly reversed along the direction from the first end to the second end, and the tip part is downwardly reversed along the direction from the third end to the fourth end. The propeller blade is provided with a pressure surface and a suction surface opposite to the pressure surface, and the movable platform further comprises a structural member, the structural member being arranged on the machine body and facing the pressure surface. The main body part is upwardly reversed along the direction from the first end to the second end to reduce or eliminate the interference between the propeller blade and the structural member.

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