CN109952247B

CN109952247B - Screw, power component and aircraft

Info

Publication number: CN109952247B
Application number: CN201780071175.3A
Authority: CN
Inventors: 刘峰; 陈鹏; 邓涛
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2017-09-20
Filing date: 2017-11-23
Publication date: 2022-05-10
Anticipated expiration: 2037-11-23
Also published as: CN109952247A; CN207242018U; WO2019056558A1

Abstract

A propeller, a power assembly and an aircraft are provided. Wherein, the screw includes: the propeller comprises a propeller clamp (10) and a blade (20), wherein the blade (20) is connected to the propeller clamp, the distance from the center of the propeller clamp (10) is 21.10% of the radius of the propeller, the attack angle of the blade (20) is 21 degrees +/-2.5 degrees, and the chord length of the blade (20) is 22.32mm +/-5 mm; -the angle of attack of the blade (20) is 16.57 ° ± 2.5 ° at a distance from the centre of the blade grip (10) of 57.14% of the radius of the propeller, the chord length of the blade (20) is 19.02mm ± 5 mm; the angle of attack of the blade (20) is 12.91 ° ± 2.5 ° at a distance of 76.19% of the radius of the propeller from the centre of the blade grip (10), and the chord length of the blade (20) is 15.77mm ± 5 mm. The structure of the propeller can be optimized, and the flight performance of the aircraft is improved.

Description

Screw, power component and aircraft

Technical Field

The invention relates to the field of aircrafts, in particular to a propeller, a power assembly and an aircraft.

Background

Propellers on aircraft, which are important key components of aircraft, are used to convert the rotation of a rotating shaft in a motor or an engine into thrust or lift.

The shape of the propeller in the prior art is mostly rectangular, the propeller has large resistance and low efficiency, so that the flying speed of the aircraft is low, the following flight distance is short, and the flying performance of the aircraft is seriously influenced.

Disclosure of Invention

The invention provides a propeller, a power assembly and an aircraft.

A propeller, comprising: the propeller comprises a propeller clamp and a blade, wherein the blade is connected to the propeller clamp, the distance from the center of the propeller clamp to the propeller clamp is 21.10% of the radius of the propeller, the attack angle of the blade is 21 +/-2.5 degrees, and the chord length of the blade is 22.32 +/-5 mm; at a distance of 57.14% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 16.57 ° ± 2.5 °, and the chord length of the paddle is 19.02mm ± 5 mm; at a distance of 76.19% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 12.91 ° ± 2.5 °, and the chord length of the paddle is 15.77mm ± 5 mm.

Further, at a distance of 19.05% of the radius of the propeller from the center of the paddle clamp, the angle of attack of the blade is 17.73 ° ± 2.5 °, and the chord length of the blade is 15.35mm ± 5 mm.

Further, the angle of attack of the blade is 12.21 ° ± 2.5 ° at a distance from the center of the blade grip of 95.24% of the radius of the propeller, and the chord length of the blade is 12.33mm ± 5 mm.

Further, the diameter of the propeller is 210mm +/-21 mm; at a distance of 40mm from the center of the blade clamp, the attack angle of the blade is 21 degrees, and the chord length of the blade is 22.32 mm; at a distance of 60mm from the center of the paddle clip, the angle of attack of the paddle is 16.57 degrees, and the chord length of the paddle is 19.02 mm; at a distance of 80mm from the centre of the blade grip, the angle of attack of the blade is 12.91 °, and the chord length of the blade is 15.77 mm.

Further, the diameter of the propeller is 210mm +/-21 mm; at a distance of 20mm from the centre of the blade grip, the angle of attack of the blade is 17.73 °, and the chord length of the blade is 15.35 mm.

Further, the diameter of the propeller is 210mm +/-21 mm; at a distance of 100mm from the centre of the blade grip, the angle of attack of the blade is 12.21 °, and the chord length of the blade is 12.33 mm.

Further, the blade comprises a downward blade surface, an upward blade back, a first lateral edge connected to one side of the blade back and the blade surface, and a second lateral edge connected to the other side of the blade back and the blade surface; the blade surface with the cross section of leaf back all is the curve, just first lateral margin is located second lateral margin below.

Further, the first side edge of the paddle is convexly formed with a convex part.

Further, the paddle includes with the link that the oar presss from both sides the connection and deviates from the end of oar clamp, the thickness of paddle by the link is to the end reduces gradually.

Further, the projection is located at the blade near the connection end.

Further, the paddle is at least two, and the at least two paddles are centrosymmetric about the center of the paddle clamp.

Further, the pitch of the blade is 111.76 mm.

A power assembly comprising a drive member and a propeller as described above, the propeller being connected to the drive member by the paddle clamp.

Further, the driving part is a motor, and the KV value of the motor is 1400 revolutions/(min. volt).

An aircraft comprising a fuselage and a power assembly as described above, the power assembly being connected to the fuselage.

Further, the aircraft comprises a plurality of power assemblies, and the rotation directions of the plurality of power assemblies are different.

Further, the aircraft is a multi-rotor aircraft.

According to the propeller provided by the embodiment of the invention, the attack angle of the blade is 21 +/-2.5 degrees at the position which is 21.10% of the radius of the propeller away from the center of the blade clamp, and the chord length of the blade is 22.32 +/-5 mm; at a distance of 57.14% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 16.57 ° ± 2.5 °, and the chord length of the paddle is 19.02mm ± 5 mm; at a distance of 76.19% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 12.91 ° ± 2.5 °, and the chord length of the paddle is 15.77mm ± 5 mm. The design of the attack angles of different parts of the paddle can reduce the resistance of the propeller in the rotation process, reduce the flight resistance of the aircraft in the flight process, improve the flight efficiency, increase the endurance distance and improve the flight performance of the aircraft.

Drawings

Fig. 1 is a top view of a propeller according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of the propeller of the embodiment shown in fig. 1, taken along the D-D section at a distance of 40mm from the center of the blade holder.

Figure 3 is a cross-sectional view of the propeller of the embodiment of figure 1 taken along the C-C section at a distance of 60mm from the centre of the blade holder.

Fig. 4 is a cross-sectional view of the propeller of the embodiment of fig. 1 taken along the line B-B at a distance of 80mm from the center of the blade holder.

Fig. 5 is a cross-sectional view of the propeller of the embodiment shown in fig. 1, taken along the line E-E, at a distance of 20mm from the centre of the blade holder.

Fig. 6 is a cross-sectional view of the propeller of the embodiment shown in fig. 1 taken along the line a-a at a distance of 100mm from the center of the blade holder.

Fig. 7 is a perspective view of a propeller according to an embodiment of the present invention.

Fig. 8 is a side view of a propeller provided by an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present invention. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

The embodiment of the invention provides a propeller which can be a positive propeller or a negative propeller. The so-called positive propeller refers to a propeller which rotates clockwise to generate lift force when viewed from a driving part such as the tail part of a motor to the head part of the motor; the term "counter-propeller" refers to a propeller that rotates counterclockwise to generate lift when viewed from the rear of the motor to the head of the motor. The structure of the positive propeller and the structure of the negative propeller are mirror symmetric, so the structure of the propeller is described below only by taking the positive propeller as an example.

Additionally, the terms upper, lower, etc. are used in this embodiment with reference to the propeller after the propeller is mounted to the aircraft and the normal operating attitude of the aircraft and should not be considered limiting.

The propeller, the power assembly and the aircraft of the present invention will be described in detail below with reference to the accompanying drawings. The features of the following examples and embodiments may be combined with each other without conflict.

Referring to fig. 1 to 4, an embodiment of the present invention provides a propeller including:

the oar presss from both sides 10 and paddle 20, include two mounting holes 101 on the oar presss from both sides 10, paddle 20 passes through mounting hole 101 connects on the oar presss from both sides 10. Of course, the paddle 20 may be integrally formed with the paddle clip 10, or may be separately machined and then fixedly mounted as a single piece. At a distance D4 of 21.10% of the radius of the propeller from the centre of the blade holder 10, the angle of attack α 1 of the blade 20 is 21 ° ± 2.5 °, and the chord length L1 of the blade 20 is 22.32mm ± 5 mm. At a distance D3 of 57.14% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 2 of the blade 20 is 16.57 ° ± 2.5 °, and the chord length L2 of the blade 20 is 19.02mm ± 5 mm. At a distance D2 of 76.19% of the radius of the propeller from the centre of the paddle clip 10, the angle of attack α 3 of the blade 20 is 12.91 ° ± 2.5 °, and the chord length L3 of the blade 20 is 15.77mm ± 5 mm.

In the present embodiment, since D4 is located 21.10% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 1 of the blade 20 is 21 ° ± 2.5 °, and the chord length L1 of the blade 20 is 22.32mm ± 5 mm. At a distance D3 of 57.14% of the radius of the propeller from the centre of the paddle clip 10, the angle of attack α 2 of the blade 20 is 16.57 ° ± 2.5 °, and the chord length L2 of the blade 20 is 19.02mm ± 5 mm. At a distance D2 of 76.19% of the radius of the propeller from the centre of the paddle clip 10, the angle of attack α 3 of the blade 20 is 12.91 ° ± 2.5 °, and the chord length L3 of the blade 20 is 15.77mm ± 5 mm. The propeller with the blades in the specific shape is defined by the parameters, so that the air resistance of the propeller can be reduced, the pulling force and the efficiency are improved, the secondary flight distance of the aircraft is increased, and the flight performance of the aircraft is improved.

Referring to table 1, it can be seen from the comparison between the test results of the propeller provided in this embodiment and the existing propeller, that when the rotation speed is 3000RPM, 4000RPM, 5000RPM, 6000RPM, 7000PRM, and 9360PRM, the tension of the propeller provided in this embodiment is greater than that of the existing propeller, that is, the propeller provided in this embodiment can provide a greater tension at the same rotation speed. Therefore, the propeller provided by the embodiment can obviously improve the pulling force under the extreme condition of large takeoff weight in a high-altitude area or a low-altitude area with reduced density, ensure enough power and prolong the endurance time at the same time, and improve the flight performance.

Common oar		The invention
				Rotational speed (RPM)	Pulling force (g)	Rotational speed (RPM)	Pulling force (g)
3000	46	3000	69
				4000	96	4000	170
5000	158	5000	258
				6000	190	6000	357
7000	320	7000	462
				9360(Max)	548	9360(Max)	561

TABLE 1

Wherein, at a distance D4 of 21.10% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 1 of the blade 20 may be 18.5 °, or 21 °, or 23.5 °, or any value therebetween, and the chord length L1 of the blade 20 may be 17.32mm, or 22.32mm, or 27.32mm, or any value therebetween. At a distance D3 of 57.14% of the radius of the propeller from the centre of the blade holder 10, the angle of attack α 2 of the blade 20 may be 14.07 ° or 16.57 ° or 19.07 °, or a value between any two of the above, and the chord length L2 of the blade 20 may be 14.02mm or 19.02mm or 24.02mm, or a value between any two of the above. At a distance D2 of 76.19% of the radius of the propeller from the centre of the paddle clip 10, the angle of attack α 3 of the blade 20 may be 10.41 ° or 12.91 ° or 15.41 °, or a value between any two of the above, and the chord length L3 of the blade 20 may be 10.77mm or 15.77mm or 20.77mm, or a value between any two of the above.

Wherein, the oar presss from both sides 10 and can be cylindric, and the oar presss from both sides 10 center and is equipped with the connecting hole, and the connecting hole is used for the cover to establish on the output of motor. The paddle 20 may be in an elongated shape, and the paddle 20 is connected to the paddle clip 10 and extends in a radial direction of the paddle clip 10. The angle of attack refers to the angle between the chord of the blade 20 and the incoming flow velocity and the chord length refers to the length of the cross section of the blade 20.

Referring to fig. 5, in this embodiment, optionally, at a position D5 which is 19.05% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 4 of the blade 20 is 17.73 ° ± 2.5 °, and the chord length L4 of the blade 20 is 15.35mm ± 5 mm. So as to further reduce the air resistance of the propeller and improve the pulling force and the efficiency. Wherein the angle of attack α 4 of the blade 20 may be 15.23 ° or 17.73 ° or 20.23 °, or a value therebetween, and the chord length L4 of the blade 20 may be 10.35mm or 15.35mm or 20.35mm, or a value therebetween.

Referring to fig. 6, in this embodiment, optionally, at a position D1 which is 95.24% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 5 of the blade 20 is 12.21 ° ± 2.5 °, and the chord length L5 of the blade 20 is 12.33mm ± 5 mm. So as to further reduce the air resistance of the propeller and improve the pulling force and the efficiency. Wherein the angle of attack α 5 of the blade 20 may be 9.71 °, or 12.21 °, or 14.71 °, or a value therebetween, and the chord length L5 of the blade 20 may be 7.33mm, or 12.33mm, or 17.33mm, or a value therebetween.

Referring again to fig. 1-4, in this embodiment, the diameter of the propeller is optionally 210mm ± 21 mm. At a distance D4 of 40mm from the centre of the blade grip 10, the angle of attack α 1 of the blade 20 is 21 °, and the chord length L1 of the blade 20 is 22.32 mm. At a distance D3 of 60mm from the centre of the blade grip 10, the angle of attack α 2 of the blade 20 is 16.57 °, and the chord length L2 of the blade 20 is 19.02 mm. At 80mm from the center of the paddle clip 10D 2, the angle of attack α 3 of the blade 20 is 12.91 °, and the chord length L3 of the blade 20 is 15.77 mm. Therefore, the air resistance of the propeller can be further reduced, and the pulling force and the efficiency are improved. Wherein the diameter of the propeller can be 189mm or 210mm or 231mm, or a value between any two of the above.

Referring again to fig. 5, in the present embodiment, the diameter of the propeller is optionally 210mm ± 21 mm. At 20mm from the center of the paddle clip 10D 5, the angle of attack α 4 of the blade 20 is 17.73 °, and the chord length L4 of the blade 20 is 15.35 mm. Therefore, the air resistance of the propeller can be further reduced, and the pulling force and the efficiency are improved. Wherein the diameter of the propeller can be 189mm or 210mm or 231mm, or a value between any two of the above.

Referring again to fig. 6, in the present embodiment, the diameter of the propeller is optionally 210mm ± 21 mm. At a distance of 100mm from the center of the paddle clip 10D 1, the angle of attack α 5 of the blade 20 is 12.21 °, and the chord length L5 of the blade 20 is 12.33 mm. Therefore, the air resistance of the propeller can be further reduced, and the pulling force and the efficiency are improved. Wherein the diameter of the propeller can be 189mm or 210mm or 231mm, or a value between any two of the above.

Referring to fig. 7 and 8, in the present embodiment, the blade 20 optionally includes a downward-facing blade surface 21, an upward-facing blade back 22, a first edge 23 connected to one side of the blade back 22 and the blade surface 21, and a second edge 24 connected to the other side of the blade back 22 and the blade surface 21. The cross-sections of the blade surface 21 and the blade back 22 are both curved, and the first edge 23 is located below the second edge 24. Because the cross sections of the blade surface 21 and the blade back 22 are both curved, and the first edge 23 is positioned below the second edge 24, the resistance of air can be reduced, and the pulling force of the blade 20 can be improved.

In this embodiment, optionally, the blade 20 includes a connecting end connected to the blade clamp 10 and a terminal end away from the blade clamp 10, and the thickness of the blade 20 gradually decreases from the connecting end to the terminal end. Because the blade 20 has no sharp torsion part, the stress is more uniform, the overlarge stress at individual positions is avoided, the structural strength is higher, and the blade is not easy to break, so that the working reliability of the propeller is improved. In addition, the end of the blade 20 far away from the blade clamp 10 is the thinnest part of the blade 20, and is beneficial to reducing air resistance.

In the present embodiment, optionally, the first edge 23 of the blade 20 is convexly formed with a protrusion 231. Thereby further increasing the drag of blade 20. Wherein the protrusion 231 may be located at the blade 20 near the connection end to further increase the pulling force of the high blade 20.

In this embodiment, optionally, there are at least two paddles 20, and the at least two paddles 20 are centrosymmetric with respect to the center of the paddle clip 10. This improves the balance of the propeller.

In this embodiment, the pitch of the blade 20 is optionally 111.76 mm. Thereby, the drag of the air can be reduced, and the pulling force of the blade 20 can be increased.

In conclusion, the propeller adopting the blades of the embodiment of the invention can obviously improve the tension in the plateau area and ensure sufficient power redundancy. Meanwhile, the performance is considered to a certain extent, the following flight distance is increased, and the flight performance of the aircraft is improved. Compared with the existing propellers on the market at present, the propeller adopting the paddle can improve the pulling force by more than 50 percent under the condition of the same rotating speed. Under the extreme condition that the takeoff weight is larger in a high-altitude area or a low-altitude area with reduced density, the aircraft can obviously improve the pulling force, ensure enough power and prolong the endurance time at the same time, and improve the flight performance.

The structure of the reverse paddle is not described any more because the structure of the reverse paddle is mirror-symmetrical to the structure of the forward paddle.

The embodiment of the invention provides a power assembly, which comprises a driving part and the propeller in any embodiment of the invention, wherein the propeller is connected with the driving part through the propeller clamp 10. The specific structure of the propeller is similar to that of the foregoing embodiment, and is not described herein again. That is, the description of the propeller in the above-described embodiments and embodiments is equally applicable to the power module provided in the embodiments of the present invention.

In the present embodiment, since D4 is located 21.10% of the radius of the propeller from the center of the paddle clip 10, the angle of attack α 1 of the blade 20 is 21 ° ± 2.5 °, and the chord length L1 of the blade 20 is 22.32mm ± 5 mm. At a distance D3 of 57.14% of the radius of the propeller from the centre of the paddle clip 10, the angle of attack α 2 of the blade 20 is 16.57 ° ± 2.5 °, and the chord length L2 of the blade 20 is 19.02mm ± 5 mm. D2 is at 76.19% department of the radius of the propeller apart from the center of the oar clamp 10, the angle of attack alpha 3 of the blade 20 is 12.91 degrees +/-2.5 degrees, the chord length L3 of the blade 20 is 15.77mm +/-5 mm, and the above parameters define the blade with a special shape.

In this embodiment, the motor KV value is optionally 1400 revolutions/(minute "volts). Therefore, the power performance of the power assembly can be ensured.

An embodiment of the invention provides an aircraft comprising a fuselage and a power assembly according to any embodiment of the invention, the power assembly being connected to the fuselage. The specific structure of the power assembly is similar to that of the previous embodiment, and is not described herein again. That is, the description of the propeller in the above-described embodiments and implementations is equally applicable to the aircraft provided by the embodiments of the present invention.

In this embodiment, optionally, the aircraft includes a plurality of power assemblies, and the rotation directions of the plurality of power assemblies are different.

In this embodiment, optionally, the aircraft is a multi-rotor aircraft.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

The disclosure of this patent document contains material which is subject to copyright protection. The copyright is owned by the copyright owner. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the patent and trademark office official records and records.

Claims

1. A propeller, comprising: oar presss from both sides and paddle, the paddle is connected on the oar presss from both sides its characterized in that:

the attack angle of the blade is 21 +/-2.5 degrees at the position which is 21.10 percent of the radius of the propeller away from the center of the blade clamp, and the chord length of the blade is 22.32mm +/-5 mm;

at a distance of 57.14% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 16.57 ° ± 2.5 °, and the chord length of the paddle is 19.02mm ± 5 mm;

at a distance of 76.19% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 12.91 ° ± 2.5 °, and the chord length of the paddle is 15.77mm ± 5 mm;

at a distance of 19.05% of the radius of the propeller from the center of the paddle clip, the angle of attack of the paddle is 17.73 ° ± 2.5 °, and the chord length of the paddle is 15.35mm ± 5 mm.

2. The propeller of claim 1 wherein the angle of attack of the blade is 12.21 ° ± 2.5 ° and the chord length of the blade is 12.33mm ± 5mm at a distance of 95.24% of the radius of the propeller from the center of the paddle clip.

3. The propeller of claim 1, wherein:

the diameter of the propeller is 210mm +/-21 mm;

at a distance of 40mm from the center of the blade clamp, the attack angle of the blade is 21 degrees, and the chord length of the blade is 22.32 mm;

at a distance of 60mm from the center of the paddle clip, the angle of attack of the paddle is 16.57 degrees, and the chord length of the paddle is 19.02 mm;

at a distance of 80mm from the centre of the blade grip, the angle of attack of the blade is 12.91 °, and the chord length of the blade is 15.77 mm.

4. The propeller of claim 1, wherein:

the diameter of the propeller is 210mm +/-21 mm;

at a distance of 20mm from the centre of the blade grip, the angle of attack of the blade is 17.73 °, and the chord length of the blade is 15.35 mm.

5. The propeller of claim 2, wherein:

the diameter of the propeller is 210mm +/-21 mm;

at a distance of 100mm from the centre of the blade grip, the angle of attack of the blade is 12.21 °, and the chord length of the blade is 12.33 mm.

6. The propeller of any one of claims 1 to 5, wherein:

the paddle comprises a downward blade surface, an upward blade back, a first lateral edge connected to one side of the blade back and the blade surface, and a second lateral edge connected to the other side of the blade back and the blade surface;

the blade surface with the cross section of leaf back all is the curve, just first lateral margin is located second lateral margin below.

7. The propeller of claim 6 wherein the first side edge of the blade is convexly formed with a protrusion.

8. The propeller of claim 7, wherein the blade includes a connecting end connected to the blade clip and a tip end facing away from the blade clip, the blade having a thickness that decreases from the connecting end to the tip end.

9. The propeller of claim 8 wherein said protrusion is located at said blade proximate said connection end.

10. The propeller of any one of claims 1 to 5 and 7 to 9 wherein there are at least two of the blades, the at least two blades being centrosymmetric about the center of the blade holder.

11. The propeller of any one of claims 1 to 5 and 7 to 9 wherein the pitch of the blades is 111.76 mm.

12. A power assembly comprises a driving piece and a propeller, and is characterized in that the propeller comprises a propeller clamp and a blade, and the blade is connected to the propeller clamp;

the propeller is connected with the driving piece through the propeller clamp, the driving piece is a motor, and the KV value of the motor is 1400 revolutions/(min-volt);

13. A power assembly according to claim 12, wherein the angle of attack of the blade is 12.21 ° ± 2.5 ° and the chord length of the blade is 12.33mm ± 5mm at a distance of 95.24% of the radius of the propeller from the centre of the blade grip.

14. The power assembly of claim 12, wherein:

the diameter of the propeller is 210mm +/-21 mm;

15. The power assembly of claim 12, wherein:

the diameter of the propeller is 210mm +/-21 mm;

16. The power assembly of claim 13, wherein:

the diameter of the propeller is 210mm +/-21 mm;

17. A power assembly according to any one of claims 12 to 16, wherein:

18. A power assembly according to claim 17, wherein the first side edge of the blade is convexly formed with a projection.

19. A power assembly according to claim 18, wherein the blade includes a connecting end connected to the blade grip and a distal end facing away from the blade grip, the blade tapering in thickness from the connecting end to the distal end.

20. A power assembly according to claim 19, wherein the projection is located on the blade proximate the attachment end.

21. A power assembly according to any of claims 12-16 and 18-20, wherein there are at least two of the paddles, the at least two paddles being centrally symmetric about the center of the paddle clamp.

22. A power assembly according to any of claims 12 to 16 and 18 to 20, wherein the pitch of the blade is 111.76 mm.

23. An aircraft comprises an aircraft body and a power assembly, wherein the power assembly is connected with the aircraft body and comprises a driving piece and a propeller;

24. The aircraft of claim 23 wherein the angle of attack of the blade is 12.21 ° ± 2.5 ° and the chord length of the blade is 12.33mm ± 5mm at a distance from the center of the paddle clip of 95.24% of the radius of the propeller.

25. The aircraft of claim 23, wherein:

the diameter of the propeller is 210mm +/-21 mm;

26. The aircraft of claim 23, wherein:

the diameter of the propeller is 210mm +/-21 mm;

27. The aircraft of claim 24, wherein:

the diameter of the propeller is 210mm +/-21 mm;

28. The aircraft of any of claims 23-27, wherein:

29. The aircraft of claim 28 wherein the first side edge of the blade is convexly formed with a protrusion.

30. The aircraft of claim 29, wherein the blade comprises a connecting end connected to the blade grip and a tip end facing away from the blade grip, the blade tapering in thickness from the connecting end to the tip end.

31. The aircraft of claim 30 wherein the protrusion is located on the blade proximate the connection end.

32. The aircraft of any of claims 23-27 and 29-31 wherein there are at least two of the paddles, the at least two paddles being centrosymmetric about a center of the paddle clamp.

33. The aircraft of any of claims 23-27 and 29-31 wherein the pitch of the blades is 111.76 mm.

34. The aircraft of claim 23, wherein the aircraft comprises a plurality of power assemblies, the plurality of power assemblies rotating in different directions.

35. The aircraft of claim 23 wherein the aircraft is a multi-rotor flight.