CN210653619U

CN210653619U - Screw and aircraft

Info

Publication number: CN210653619U
Application number: CN201921471969.1U
Authority: CN
Inventors: 张海浪
Original assignee: Autel Robotics Co Ltd
Current assignee: Shenzhen Autel Intelligent Aviation Technology Co Ltd
Priority date: 2019-09-05
Filing date: 2019-09-05
Publication date: 2020-06-02
Anticipated expiration: 2029-09-05
Also published as: WO2021043330A1

Abstract

The utility model discloses a screw and aircraft belongs to aircraft technical field. The propeller comprises blades, the blades are 20% away from the center of a propeller hub, the first chord length is 58 mm-62 mm, and the first torsion angle is 21.5-22.5 degrees; the second chord length is 45 mm-47 mm at the position 50% away from the center of the propeller hub, and the second torsion angle is 15.5-16.5 degrees; at a position 75% away from the center of the propeller hub, the third chord length is 30-32 mm, and the third torsion angle is 11.5-12.5 degrees; the fourth chord length is 21-23 mm at a position 100% away from the center of the propeller hub, and the fourth torsion angle is 8.5-9.5 degrees; also included are a first airfoil and a second airfoil. The aircraft comprises the propeller. The utility model discloses a set up specific wing section, torsion angle and chord length distribution, can effectively guarantee that the paddle has the best working property, can effectively improve the pneumatic efficiency of screw.

Description

Screw and aircraft

Technical Field

The utility model relates to an aircraft technical field especially relates to a screw and aircraft.

Background

The propeller is an important part of the aircraft, and is used for converting the rotation of the output shaft of the motor into thrust or lift force so as to realize the taking off and landing, steering, hovering and the like of the aircraft.

The shape of the propeller in the prior art is generally rectangular, and due to the fact that the rectangular propeller is large in resistance and low in efficiency, the aerodynamic efficiency of the rotation of the output shaft of the motor, which is converted into the thrust or the lift force, is affected, and the requirement of the expected tension or the lift force cannot be met when the aircraft works.

Therefore, it is desirable to provide a propeller and an aircraft to solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a screw, pneumatic efficiency is high.

Another object of the present invention is to provide an aircraft, which can effectively prolong the hovering time of the aircraft.

To achieve the purpose, the utility model adopts the following technical proposal:

a propeller comprises blades, wherein the blades are 20% away from the center of a propeller hub, the first chord length is 58 mm-62 mm, and the first torsion angle is 21.5-22.5 degrees;

the second chord length is 45 mm-47 mm at the position 50% away from the center of the propeller hub, and the second torsion angle is 15.5-16.5 degrees;

at a position 75% away from the center of the propeller hub, the third chord length is 30-32 mm, and the third torsion angle is 11.5-12.5 degrees;

the fourth chord length is 21-23 mm at a position 100% away from the center of the propeller hub, and the fourth torsion angle is 8.5-9.5 degrees;

the blade comprises a first airfoil and a second airfoil, wherein the relative thickness of the first airfoil is 14% -16% at a position 0-20% away from the center of the hub, the ratio of the vertical distance between the position of the maximum thickness of the first airfoil and the leading edge to the corresponding chord length is 27% -28%, the relative camber of the first airfoil is 2% -4%, and the ratio of the vertical distance between the position of the maximum camber of the first airfoil and the leading edge to the corresponding chord length is 32% -33%;

the second airfoil is 30-100% away from the center of the propeller hub, the relative thickness of the second airfoil is 8-9%, the ratio of the vertical distance between the position with the maximum thickness of the second airfoil and the front edge to the corresponding chord length is 35-36%, the relative camber of the second airfoil is 5-6%, and the ratio of the vertical distance between the position with the maximum camber of the second airfoil and the front edge to the corresponding chord length is 43-44%.

Preferably, at 20% from the hub centre, the first chord length is 60mm and the first torque angle is 22 °;

at 50% from the hub center, the second chord length is 46mm and the second twist angle is 16 °;

at 75% from the hub center, the third chord length is 31mm and the third twist angle is 12 °;

at 100% from the hub centre, the fourth chord length is 22mm and the fourth twist angle is 9 °.

Preferably, the first airfoil is 0-20% away from the center of the hub, the relative thickness of the first airfoil is 15%, the ratio of the vertical distance from the maximum thickness position of the first airfoil to the leading edge to the corresponding chord length is 27.5%, the relative camber of the first airfoil is 3.0%, and the ratio of the vertical distance from the maximum camber position of the first airfoil to the leading edge to the corresponding chord length is 32.5%.

Preferably, the second airfoil has a relative thickness of 8.5% at a position 30-100% from the center of the hub, a vertical distance to a leading edge at a position of maximum thickness of the second airfoil and a corresponding chord length ratio of 35.5%, a relative camber of the second airfoil is 5.5%, and a vertical distance to a leading edge at a position of maximum camber of the first airfoil and a corresponding chord length ratio of 43.5%.

Preferably, the blade further comprises a transition part at a position 30% -100% away from the center of the hub, and two ends of the transition part are smoothly transited with the first airfoil and the second airfoil respectively.

Preferably, the blade includes a blade back, a blade surface disposed opposite to the blade back, a leading edge connecting the blade surface and one side of the blade back, and a trailing edge connecting the blade surface and the other side of the blade back, the blade surface, the leading edge, and the trailing edge together enclose the blade having a blade root and a blade tip, the blade root is located at one side close to the center of the hub, and the blade tip is located at one side far from the center of the hub.

Preferably, a portion of the trailing edge adjacent to the blade root is provided with a first projection extending away from the leading edge, wherein the first projection has a cross-sectional area that decreases away from the leading edge.

Preferably, the propeller comprises two of said blades, the two blades being centrally symmetrical about the centre of the hub.

An aircraft comprising a propeller as described in any preceding claim.

Preferably, the aircraft is a drone.

The utility model has the advantages that:

the utility model discloses a paddle for the screw sets up specific chord length, torsion angle and wing section and distributes for the screw has the combination of "coarse pitch + high lift line slope wing section", thereby can effectively guarantee that the paddle has the best working property, and improves the pneumatic efficiency of screw.

Drawings

Fig. 1 is a schematic structural diagram of a propeller according to an embodiment of the present invention;

fig. 2 is a top view of a propeller in an embodiment of the invention;

FIG. 3 is a cross-sectional view A-A of FIG. 2;

FIG. 4 is a schematic cross-sectional view of a propeller blade in an embodiment of the present invention;

fig. 5 is a graph comparing the rotation speed and the pulling force of the propeller and the conventional propeller according to the embodiment of the present invention.

In the figure:

1-a hub; 2-a blade;

21-leaf back; 22-leaf surface; 23-leading edge; 24-the trailing edge; 25-a blade root; 26-blade tip; 27-a first projection;

l-chord, α -twist angle, t-thickness, f-camber, m-camber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

As shown in fig. 1 and 2, the present embodiment discloses a propeller for an aircraft, which includes a hub 1 connected to a driving motor, and blades 2 connected to the hub 1. Two blades 2 are included in this embodiment, the two blades 2 being centrally symmetrical about the centre of the hub 1. When the propeller works, the blades 2 rotate around the center of the propeller hub 1 under the action of the driving motor so as to disturb airflow to generate lift force or pulling force to drive the aircraft to move. It will be appreciated that the centre of the fixing base is also the centre of the hub 1. The blade 2 of the present embodiment may be made of any material known in the art, including but not limited to steel, aluminum alloy, plastic, carbon fiber, and the like. Various prior art processes including molding, stamping, forging, etc. may also be used in the manufacture.

Specifically, the blade 2 includes a blade back 21, a blade surface 22 disposed opposite to the blade back 21, a leading edge 23 connecting one side of the blade surface 22 and the blade back 21, and a trailing edge 24 connecting the other side of the blade surface 22 and the blade back 21, where the blade back 21, the blade surface 22, the leading edge 23, and the trailing edge 24 together enclose to form the blade 2 having a blade root 25 and a blade tip 26, the blade root 25 is located on one side close to the center of the hub 1, and the blade tip 26 is located on one side far from the center of the hub 1. Wherein, the blade back 21 is the upward surface of the blade 2 in the flying process of the aircraft; the blade surface 22 is the downward surface of the blade 2 in the flying process of the aircraft; the trailing edge 24 is located below the leading edge 23, i.e., horizontally from the leading edge 23 to the trailing edge 24, the blade back 21 and the blade surface 22 are curved instead of flat, and the curved openings of the blade back 21 and the blade surface 22 face downward. In this embodiment, the portion of the trailing edge 24 adjacent the blade root 25 is provided with a first tab 27, the first tab 27 extending away from the leading edge 23, wherein the first tab 27 has a cross-sectional area that gradually decreases away from the leading edge 23. The first protruding part 27 is arranged to enhance the strength of the blade 2 near the blade root 25, and at the same time, to better reduce the air resistance to the blade root 25, so that the blade 2 has better pulling force or lift force when rotating.

In order to further increase the drag or lift provided by the propeller to the aircraft during rotation, the present embodiment is designed with respect to the chord length and twist angle α of the blade 2, and the relative thickness, relative camber and other corresponding values of the airfoil of the blade 2, as shown in fig. 3 and 4, where the chord length L is the length of the chord L as a line connecting the leading edge 23 and the trailing edge 24 of the cross-section, the twist angle α indicates the angle between the chord L and the rotation plane, the thickness t is the maximum distance between the blade back 21 and the blade surface 22 of the cross-section, the relative thickness is the ratio of the thickness t to the chord length, the camber f is the maximum distance between the mean camber line m and the chord L of the cross-section in the direction perpendicular to the chord L (where a series of inscribed circles are made between the blade back 21 and the blade surface 22, the lines of the inscribed circles are mean camber lines), and the relative camber is the ratio of camber f to the chord length.

Specifically, the blade 2 can be selected such that the first chord length is 58mm to 62mm and the first torsion angle is 21.5 ° to 22.5 ° at a position 20% from the center of the hub 1, the second chord length is 45mm to 47mm and the second torsion angle is 15.5 ° to 16.5 ° at a position 50% from the center of the hub 1, the third chord length is 30mm to 32mm and the third torsion angle is 11.5 ° to 12.5 ° at a position 75% from the center of the hub 1, the fourth chord length is 21mm to 23mm and the fourth torsion angle is 8.5 ° to 9.5 ° at a position 100% from the center of the hub 1, wherein the pitch and the torsion angle α are in a positive relationship, and the pitch and the torsion angle α of the blade 2 are specified and the larger torsion angle α is provided, so that the propeller can have a large pitch and can generate a large pulling force on the premise of a small blade diameter.

Further optionally, the blade 2 of this embodiment includes a first airfoil and a second airfoil, where the first airfoil is located 0-20% away from the center of the hub 1, the relative thickness of the first airfoil is 14% -16%, the ratio of the vertical distance between the maximum thickness position of the first airfoil and the leading edge 23 to the corresponding chord length is 27% -28%, the relative camber of the first airfoil is 2% -4%, and the ratio of the vertical distance between the maximum camber position of the first airfoil and the leading edge 23 to the corresponding chord length is 32% -33%; the second airfoil is located 30% -100% away from the center of the propeller hub 1, the relative thickness of the second airfoil is 8% -9%, the ratio of the vertical distance between the maximum thickness position of the second airfoil and the front edge 23 to the corresponding chord length is 35% -36%, the relative camber of the second airfoil is 5% -6%, and the ratio of the vertical distance between the maximum camber position of the second airfoil and the front edge 23 to the corresponding chord length is 43% -44%; the blade 2 further comprises a transition part which is 20% -30% away from the center of the hub 1, and two ends of the transition part are smoothly transited with the first airfoil and the second airfoil respectively. Wherein the transition portion can be freely transitioned. By specifying the airfoil shape of the blade 2, the blade 2 has an airfoil shape with a high gradient of lift line, so that the propeller of the embodiment and the conventional propeller have a larger pulling force under the condition that the driving motor provides the same driving force.

By setting specific chord length, torsion angle α and airfoil distribution for the blades 2 of the propeller, the propeller has a combination of 'big pitch + high lift line slope airfoil', thereby effectively ensuring that the blades 2 have optimal working performance and improving the aerodynamic efficiency of the propeller.

Specifically, in the present embodiment, the diameter of the propeller is 450mm, the radius of the hub 1 is 15mm, the widest position of the blade 2 is located at about one fifth of the length direction of the blade 2, that is, the first protrusion 27 is located near about one fifth of the blade 2, and at 20% from the center of the hub 1, the first chord length is 60mm, and the first torsion angle is 22 °; at 50% from the centre of the hub 1, the second chord length is 46 and the second twist angle is 16 °; at 75% from the centre of the hub 1, the third chord length is 31 and the third twist angle is 12 °; at 100% from the centre of the hub 1, the fourth chord length is 22mm and the fourth twist angle is 9 °. The first airfoil is 0-20% away from the center of the hub 1, the relative thickness of the first airfoil is 15%, the ratio of the vertical distance between the maximum thickness position of the first airfoil and the leading edge 23 to the corresponding chord length is 27.5%, the relative camber of the first airfoil is 3.0%, and the ratio of the vertical distance between the maximum camber position of the first airfoil and the leading edge 23 to the corresponding chord length is 32.5%; the relative thickness of the second airfoil is 8.5% at a position 30% -100% away from the center of the hub 1, the ratio of the vertical distance between the position with the maximum thickness of the second airfoil and the leading edge 23 to the corresponding chord length is 35.5%, the relative camber of the second airfoil is 5.5%, and the ratio of the vertical distance between the position with the maximum camber of the second airfoil and the leading edge 23 to the corresponding chord length is 43.5%. Wherein the propeller in the embodiment is suitable for the Reynolds number range of 10⁵～10⁶。

As shown in fig. 5, by comparing and analyzing the propeller in this embodiment with a conventional propeller, it is obvious that the propeller in this embodiment has a larger pulling force at the same rotation speed, which means that the propeller in this embodiment has a better working performance, and the aerodynamic efficiency of the propeller can be effectively improved.

In addition, this embodiment still discloses an aircraft of using above-mentioned screw, if use the unmanned aerial vehicle of above-mentioned screw, through using behind the above-mentioned screw, power efficiency obtains promoting among the unmanned aerial vehicle to can effectively prolong unmanned aerial vehicle's hover time.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A propeller, characterized in that the propeller comprises a hub (1) and blades (2) connected to the hub (1), the blades (2) having a first chord length of 58mm to 62mm at a distance of 20% from the center of the hub (1), and a first twist angle of 21.5 ° to 22.5 °;

the second chord length is 45 mm-47 mm at the position 50% away from the center of the propeller hub (1), and the second torsion angle is 15.5-16.5 degrees;

the third chord length is 30 mm-32 mm and the third torsion angle is 11.5-12.5 degrees at the position 75% away from the center of the propeller hub (1);

the fourth chord length is 21 mm-23 mm and the fourth torsion angle is 8.5-9.5 degrees at the position 100% away from the center of the propeller hub (1);

the blade (2) comprises a first airfoil and a second airfoil, wherein the relative thickness of the first airfoil is 14% -16% at a position 0-20% away from the center of the hub (1), the ratio of the vertical distance between the position with the maximum thickness of the first airfoil and the leading edge (23) to the corresponding chord length is 27% -28%, the relative camber of the first airfoil is 2% -4%, and the ratio of the vertical distance between the position with the maximum camber of the first airfoil and the leading edge (23) to the corresponding chord length is 32% -33%;

the second airfoil is 30-100% away from the center of the propeller hub (1), the relative thickness of the second airfoil is 8-9%, the ratio of the vertical distance between the maximum thickness position of the second airfoil and the front edge (23) to the corresponding chord length is 35-36%, the relative camber of the second airfoil is 5-6%, and the ratio of the vertical distance between the maximum camber position of the second airfoil and the front edge (23) to the corresponding chord length is 43-44%.

2. The propeller according to claim 1, wherein at 20% from the centre of the hub (1), the first chord length is 60mm and the first torque angle is 22 °;

at 50% from the centre of the hub (1), the second chord length is 46mm and the second twist angle is 16 °;

at 75% from the centre of the hub (1), the third chord length is 31mm and the third twist angle is 12 °;

at 100% from the centre of the hub (1), the fourth chord length is 22mm and the fourth twist angle is 9 °.

3. The propeller according to claim 1, wherein the first airfoil is 0-20% from the center of the hub (1), the relative thickness of the first airfoil is 15%, the ratio of the vertical distance to the leading edge (23) at the position of maximum thickness of the first airfoil to the corresponding chord length is 27.5%, the relative camber of the first airfoil is 3.0%, and the ratio of the vertical distance to the leading edge (23) at the position of maximum camber of the first airfoil to the corresponding chord length is 32.5%.

4. The propeller according to claim 1, wherein the second airfoil is between 30% and 100% from the center of the hub (1), the relative thickness of the second airfoil is 8.5%, the ratio of the perpendicular distance to the corresponding chord length at the location of maximum thickness of the second airfoil to the leading edge (23) is 35.5%, the relative camber of the second airfoil is 5.5%, and the ratio of the perpendicular distance to the corresponding chord length at the location of maximum camber of the second airfoil to the leading edge (23) is 43.5%.

5. The propeller according to claim 1, wherein the blade (2) further comprises a transition at 30% to 100% from the center of the hub (1), the transition having two ends smoothly transitioning with the first airfoil and the second airfoil, respectively.

6. The propeller according to claim 1, wherein the blade (2) comprises a blade back (21), a blade surface (22) arranged opposite to the blade back (21), a leading edge (23) connecting one side of the blade surface (22) and the blade back (21), and a trailing edge (24) connecting the other side of the blade surface (22) and the blade back (21), wherein the blade back (21), the blade surface (22), the leading edge (23), and the trailing edge (24) jointly enclose the blade (2) having a blade root (25) and a blade tip (26), wherein the blade root (25) is located on a side close to the center of the hub (1), and the blade tip (26) is located on a side far away from the center of the hub (1).

7. The propeller according to claim 6, wherein a portion of the trailing edge (24) near the blade root (25) is provided with a first protrusion (27), the first protrusion (27) extending away from the leading edge (23), wherein the cross-sectional area of the first protrusion (27) decreases gradually away from the leading edge (23).

8. The propeller as claimed in any one of claims 1 to 7, wherein the propeller comprises two of the blades (2), the two blades (2) being centrally symmetrical about the centre of the hub (1).

9. An aircraft comprising a propeller as claimed in any one of claims 1 to 8.

10. The aircraft of claim 9, wherein the aircraft is a drone.