CN114104266A - Screw, power component and aircraft - Google Patents

Abstract

The invention provides a propeller, a power assembly and an aircraft, relates to the technical field of flight, and aims to solve the technical problems that the tips of propeller wings are easy to generate vortex and cavitation, so that the noise is high and the resistance is increased. The propeller comprises a central column and at least two blades, the wing root of each blade is arranged on the central column, each blade is provided with two blade sections and a blade tip transition section, the wing root of each blade section is connected with the central column, and each blade section is provided with a first front edge facing the wind and a first rear edge opposite to the first front edge; the wing tip transition section is a curved surface transition section, the wing tip transition section is provided with a second front edge and a second rear edge opposite to the second front edge, the first front edges of the two blade sections are in transition connection through the second front edge, the first rear edges of the two blade sections are in transition connection through the second rear edge, and the second front edge and the second rear edge are both arc-shaped edges. The propeller provided by the invention is used in an aircraft.

Description

Screw, power component and aircraft

Technical Field

The present disclosure relates to the field of flight, and more particularly, to a propeller, a power assembly, and an aircraft.

Background

At present, because straight blades are mostly adopted by propellers used by common airplanes, the blade tip part of the propellers is not specially processed, blade tip vortex and cavitation are easy to generate, so that the noise is larger and the resistance is increased, and therefore, the economy and the environmental friendliness of the straight blades are poor. Even partially modified propeller tips, such as the addition of wingtips to the tip portion, are not ideal for noise improvement and drag reduction.

Disclosure of Invention

The invention aims to provide a propeller, which is used for reducing vortex and cavitation at the tip of the propeller and reducing noise and resistance. The aircraft adopting the propeller can reduce the noise of the aircraft and reduce the influence on the surrounding people when flying in dense population areas.

In order to achieve the above purpose, the invention provides the following technical scheme:

the embodiment of the invention provides a propeller, which comprises a central column and at least two blades, wherein the wing root of each blade is arranged on the central column, each blade is provided with two blade sections and a blade tip transition section, the wing root of each blade section is connected to the central column, and each blade section is provided with a first front edge facing the wind and a first rear edge opposite to the first front edge;

the wing tip transition section is a curved transition section, the wing tip transition section is provided with a second front edge and a second rear edge opposite to the second front edge, the first front edges of the two blade sections are in transition connection through the second front edge, the first rear edges of the two blade sections are in transition connection through the second rear edge, and the second front edge and the second rear edge are both arc-shaped edges;

between the first leading edges of the two blade segments, the two blade segments have a trajectory of the first leading edges that is a catenary.

According to at least one embodiment of the present disclosure, the edge line of the arc-shaped edge is a catenary line.

According to at least one embodiment of the present disclosure, the edge line spacing of the second leading edge from the second trailing edge is at least 18 mm.

According to at least one embodiment of the present disclosure, a maximum distance between the edge line of the second front edge and the central pillar is a first distance, a maximum distance between the edge line of the second rear edge and the central pillar is a second distance, the first distance is greater than the second distance, and a difference between the first distance and the second distance is 5mm ± 2 mm.

According to at least one embodiment of the present disclosure, each of the blade segments is a curved blade segment; wherein the content of the first and second substances,

the edge line of the first leading edge is continuous in curvature with the edge line of the second leading edge; and/or the edge line of the first trailing edge is continuous in curvature with the edge line of the second trailing edge.

According to at least one embodiment of the present disclosure, the shaft of the center post is a circular shaft; wherein the content of the first and second substances,

the trace of the first leading edge is tangent to the surface of the circular shaft; and/or the presence of a gas in the gas,

the second leading edge has a trajectory that is tangential to the surface of the circular shaft.

According to at least one embodiment of the present disclosure, the two blade segments have a trajectory of the first leading edge forming an angle of 45 ° ± 5 ° with a tangent to the surface of the circular shaft.

According to at least one embodiment of the present disclosure, each of the blade segments has a plurality of airfoil sections distributed along a spanwise direction of the blade segment; wherein the content of the first and second substances,

the chord length and/or the angle of attack of each airfoil section increases and then decreases from the root in the direction of deployment of the blade section.

According to at least one embodiment of the present disclosure, when the airfoil section is located at a first target spanwise position of the blade section, the chord length of the airfoil section is 16% ± 1% of the propeller radius, the angle of attack is 19.7 ° ± 0.1 °, and the first target spanwise position is at a distance of 20% ± 1% of the propeller radius from the central axis of the central post; and/or the presence of a gas in the gas,

when the airfoil section is located at a second target spanwise position of the blade section, the chord length of the airfoil section is 18% + -1% of the radius of the propeller, the attack angle is 22.2 ° + -0.1 °, and the distance between the second target spanwise position and the central axis of the central column is 27% + -1% of the radius of the propeller;

when the airfoil section is located at a third target spanwise position of the blade section, the chord length of the airfoil section is 11% + -1% of the radius of the propeller, the attack angle is 9.7 degrees +/-0.1%, and the distance between the third target spanwise position and the central axis of the central column is 80% + -1% of the radius of the propeller.

According to at least one embodiment of the present disclosure, the airfoil profile of at least one of the blade sections is one of a concave-convex airfoil profile, a plano-convex airfoil profile, a symmetric airfoil profile, a double-convex airfoil profile, and an S-airfoil profile.

According to at least one embodiment of the present disclosure, the thickness of the blade segment increases and then decreases along the chord length of the blade segment,

the maximum thickness of the blade section is 7.28% + -0.5% of the chord length of the corresponding chord line along the length direction of the chord line of the blade section, the maximum thickness of the blade section is located at a position corresponding to a first chord line position of the chord line, and the first chord line position is 24.7% + -0.5% of the chord length of the chord line.

According to at least one embodiment of the present disclosure, along the chord length direction of the blade segment, the blade segment has a curvature with a maximum curvature of 5.49% ± 0.5% of the chord length of the respective chord, the maximum curvature of the curvature corresponding at the location of the blade segment to a second chord position of the chord of 43.6% ± 0.5% of the chord length.

According to at least one embodiment of the present disclosure, the wing root positions of the two blade sections are the same as the wing root position of the aft blade along the axial direction of the center post, or the wing root position of the fore blade is different from the wing root position of the aft blade along the height direction of the center post.

According to at least one embodiment of the present disclosure, the paddles are integrally formed with the center post or detachably connected.

Compared with the prior art, the propeller has the following advantages:

the propeller provided by the invention is provided with a central column and at least two paddles, wherein the wing root of each paddle is connected to the central column, and the rotation of the central column is driven to drive the rotation of the paddles to generate lift force. Wherein, every paddle has two paddle sections and wing tip changeover portion, and two paddle sections pass through the wing tip changeover portion and connect, because wing tip changeover portion and two paddle sections smooth connection respectively for compare with adopting straight paddle or increase the wingtip at the wing tip, the noise is littleer, the resistance also diminishes. Meanwhile, the blade tip is not thin and sharp, so that the blade tip is not easy to seriously hurt personnel, the impact resistance is better, and the blade tip is not easy to damage when the foreign matter is impacted. The two wing roots of the blade are connected to the central column as a whole, and the two blade sections are respectively provided with a first front edge facing the wind and a first rear edge opposite to the first front edge, so that the blade can obtain better lift force and is beneficial to the process manufacturing of the blade. The wing tip transition section is a curved transition section, and two blades are in natural transition, specifically, the wing tip transition section is provided with a second front edge and a second rear edge opposite to the second front edge, the first front edges of the two blade sections are in transition connection through the second front edge, the first rear edges of the two blade sections are in transition connection through the second rear edge, the second front edge and the second rear edge are both arc-line-shaped edges, and a trace of the first front edges of the two blade sections is a catenary line between the first front edges of the two blade sections, so that the trace of the first front edges is in smooth transition from a starting point to an end point, and the surface of the blades is in smooth transition.

The invention also provides a power assembly, which comprises a driving piece and the propeller, wherein the propeller is in transmission connection with the driving piece.

Compared with the prior art, the power assembly has the same advantages as those of the propeller, and the detailed description is omitted.

The invention also provides an aircraft, which comprises a fuselage and at least one power assembly, wherein the power assembly is arranged on the fuselage.

According to at least one embodiment of the present disclosure, the number of the power assemblies is plural; wherein the content of the first and second substances,

when the aircraft is in a flight state, the rotation directions of propellers contained in the power assemblies are different; or the like, or, alternatively,

at least two propellers contained by the power assembly are coaxially arranged, and when the aircraft is in a flying state, the rotating directions of the propellers contained by the at least two power assemblies are the same.

Compared with the prior art, the aircraft has the advantages which are the same as those of the propeller, and the detailed description is omitted.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

Fig. 1 is a schematic illustration of an airfoil cross-sectional structure according to an embodiment of the present disclosure.

FIG. 2 is a schematic diagram of a blade leading edge trace according to an embodiment of the present disclosure.

Fig. 3a is a perspective view of a propeller configuration according to an embodiment of the present disclosure.

Fig. 3b is a side view schematic of a propeller configuration according to an embodiment of the present disclosure.

Fig. 3c is a schematic top view of a propeller configuration according to an embodiment of the present disclosure.

Fig. 4a is a schematic perspective view of a two propeller configuration according to an embodiment of the present disclosure.

Fig. 4b is a side view schematic diagram of a two propeller configuration according to an embodiment of the present disclosure.

Fig. 4c is a schematic top view of a two propeller configuration according to an embodiment of the present disclosure.

Fig. 5a is a schematic perspective view of a triple propeller configuration according to an embodiment of the present disclosure.

Fig. 5b is a side view schematic of a triple propeller configuration according to an embodiment of the present disclosure.

Fig. 5c is a schematic top view of a triple propeller configuration according to an embodiment of the present disclosure.

Detailed Description

The present disclosure will be described in further detail with reference to the drawings and embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present disclosure. It should be further noted that, for the convenience of description, only the portions relevant to the present disclosure are shown in the drawings.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

The wing tips of the existing propeller generate larger noise and the resistance is increased, so that the working efficiency of the propeller is lower. At the same time, a sharp tip may also cause cuts to personnel.

Referring to fig. 1, according to an embodiment of the present disclosure, there is provided a propeller comprising a central post and at least two blades, a root of each blade being provided on the central post 40, each blade having two blade sections (10, 20) and a tip transition section 30, the root of each blade section being connected to the central post 40, each blade section having a first leading edge (101, 201) facing the wind, and a first trailing edge (103, 203) opposite to the first leading edge (101, 201); the wing tip transition section 30 is a curved transition section, the wing tip transition section 30 is provided with a second leading edge 301 and a second trailing edge 302 opposite to the second leading edge, the first leading edges of the two blade sections are in transition connection through the second leading edge 301, the first trailing edges of the two blade sections are in transition connection through the second trailing edge 302, and both the second leading edge 301 and the second trailing edge 302 are arc-line-shaped edges; between the first leading edges of the two blade segments, the two blade segments have a trajectory of the first leading edge that is a catenary.

The two blade sections (10, 20) are smoothly transitioned through the tip transition section 30 so that the tip of the blade does not generate significant drag and noise. The tip transition section 30 is a curved transition section, the first leading edges of the two blade sections are transitionally connected by a second leading edge 301, and the first trailing edges of the two blade sections are transitionally connected by a second trailing edge 302. The second leading edge 301 and the second trailing edge 302 are both arc-shaped edges, so that the transition is smooth. The upper airfoil surface of the blade section 10 is in curve transition with the lower airfoil surface of the blade section 20, the lower airfoil surface of the blade section 10 is in curve transition with the upper airfoil surface of the blade section 20, the wing tip transition section 30 forms a torsion structure, so that the curve between the blade section 10 and the blade section 20 is in smooth transition, and the wing tip transition section 30 of the torsion structure avoids the sharp wing tip from generating large wind resistance and noise. The two blade sections have a portion of the first leading edge trace 50 between the first leading edges of the two blade sections being a catenary line, and a trace between the first leading edge 101 of the blade section 10 and the first leading edge 201 of the blade section 20 smoothly transitions to an edge line of the first leading edges of the two blade sections, which is a connecting line between the first leading edge traces of the two blade sections. By setting the trajectory between the first leading edges of the two blade sections as a catenary, the airfoil design of the blade has a higher lift. Meanwhile, the surface of the blade is in smooth transition, the whole blade has smaller stress, and the whole blade is integrally formed, so that the strength of the blade is very high, and the working reliability of the prepared whole propeller is very high.

In certain embodiments, the edge line of the arcuate edge is a catenary line. The curves for achieving the smooth transition are various, and illustratively, the wingtip transition section 30 of the embodiment of the present invention employs a catenary, where the catenary is not necessarily a strictly catenary, and the second leading edge 301 or the second trailing edge 302 may be an approximate catenary. The first front edge or the first rear edge between the blade section 10 and the blade section 20 adopts a catenary curve transition, and in the rotating process of the whole blade, exemplarily, the edge lines of the first front edges of the two blade sections are respectively tangent to the edge line of the second front edge 301, so that the whole airfoil shape of the blade is in smooth transition, and under a certain rotating speed, the centrifugal force generated by the whole blade and the internal tension thereof can be balanced with each other, thereby avoiding the blade from bending or twisting, and ensuring the stability and reliability of the aerodynamic shape of the blade.

In view of the manufacturing process of the propeller blade, the minimum spacing between the second leading edge 301 and the second trailing edge 302 of the tip transition section 30 of the blade is 18 mm. When the interval between the second leading edge 301 and the second trailing edge 302 is less than 18mm, the wing tip transition section 30 is a transition curved surface and presents a twisted structure, and thus the existing machining and manufacturing process and material cannot or are difficult to machine, or the machining precision is difficult to ensure that the wing tip transition section 30 makes the blade section 10 and the blade section 20 perform curve transition.

In some embodiments, the maximum distance between the edge line of the second leading edge 301 and the central pillar 40 is a first distance, the maximum distance between the edge line of the second trailing edge 302 and the central pillar 40 is a second distance, the first distance is greater than the second distance, and the difference between the first distance and the second distance is 5mm ± 2 mm.

The farthest point of the second leading edge 301 from the central post 40 is relative to the farthest point of the second trailing edge 302 from the central post 40, and the second leading edge 301 is further away from the central post 40 by a difference, illustratively 5mm, 4.5mm, or 5.5 mm. In addition to ensuring that the tip transition section can be manufactured by machining and manufacturing processes in actual production, the upper airfoil surface of the blade section 10 can be ensured to be smoothly transited to the lower airfoil surface of the blade section 20, and the lower airfoil surface of the blade section 10 can be ensured to be smoothly transited to the upper airfoil surface of the blade section 20.

In order to enable the blade section 10 to smoothly transition to the blade section 20, referring to fig. 1 and fig. 2, each blade section is a curved blade section, wherein the edge lines of the first leading edge (101, 201) and the second leading edge 301 have continuous curvature; and/or the edge line of the first trailing edge (103, 203) is continuous in curvature with the edge line of the second trailing edge 302.

The two ends of the second leading edge 301 are continuously connected with the leading edge trace of the blade section 10 and the leading edge trace of the blade section 20 through curvatures respectively, the leading edge trace refers to a line formed by vertexes of leading edges of all airfoil sections, the leading edge trace refers to an edge line of the first leading edge of each blade section, compared with the connection point which adopts tangent line continuity, the connection point which adopts curvature continuity is more gentle, and is very important for smooth transition of the connection point, and because tiny sudden changes of the blades can generate great resistance and noise in the high-speed rotation process of the propeller, the resistance and the noise of the blades can be controlled and reduced by adopting the connection point which has curvature continuity. Based on the manner of continuous curvature with both ends of the second leading edge 301, the second trailing edge 302 is also connected with the trailing edge trace of the blade section 10 and the trailing edge trace of the blade section 20 respectively in a manner of continuous curvature, and the transition is more gradual, where the trailing edge trace is also the first trailing edge line of each blade section.

In some embodiments, the shaft of the center post 40 is a circular shaft; illustratively, it may also be an elliptical shaft, wherein the trajectory of the first leading edge is tangential to the surface of the circular shaft.

Referring to fig. 2, the first leading edge trace 50 of the blade is developed from the central pillar 40 outward from the starting point 501, wherein the first leading edge trace 50 is tangent to the outer circle of the central pillar 40 at the starting point 501, and the first leading edge trace 50 is tangent to the outer circle of the central pillar 40 at the ending point 502 along the first leading edge 101 of the blade segment 10, the trace between the first leading edges of the two blade segments, and the first leading edge 201 of the blade segment 20, and transition back to the ending point 502 of the central pillar 40. The first leading edge trace 50 starts and ends tangentially to the outer circle of the center post 40 so that a smooth transition from the center post 40 at the root of each blade segment may otherwise form turbulence at the root, affecting lift. The arrangement structure ensures that the blades are stable and reliable in the rotating process, the air flow enters and outputs smoothly at the position where the blade root of each blade is close to the central column 40, and the efficiency of the propeller at the position of the central column can be improved.

In some embodiments, two blade segments have first leading edge traces 50 that form a tangent angle of 45 ° ± 5 ° with the surface of the circular shaft. Because the starting point 501 of the first leading edge trace of the blade section is tangent to the excircle of the central column 40, the end point 502 of the leading edge trace of the blade is tangent to the excircle of the central column 40, and correspondingly, the included angle between the tangent lines is 45 degrees, the whole blade, including the blade section 10, the blade section 20 and the wing tip transition section 30, is streamline, the resistance is small, the efficiency is high, and the flight performance of the aircraft is further improved. It will be appreciated that the angle between the two tangent lines can be adjusted according to the number of blades, and is not limited to 45 ° ± 5 °, but in some embodiments, such as 4 blade configurations, this angle of 45 ° ± 5 ° tangent line is more beneficial for obtaining optimal lift.

In certain embodiments, each blade section has a plurality of airfoil sections distributed along a spanwise direction of the blade section; wherein, the chord length and/or the attack angle of each airfoil section are increased and then decreased from the root along the unfolding direction of the blade section.

For best flight efficiency, the airfoil profile of the blade section 10 and the blade section 20 is controlled by the airfoil profile sections, and each airfoil profile section is in smooth transition, in the embodiment of the invention, a plurality of airfoil profile sections are distributed along the spanwise direction of the blade section, the number of specific airfoil profile sections is selected according to actual size control in some embodiments, and the airfoil profile of the blade section 10 and the blade section 20 can be controlled by 9 airfoil profile sections. And along the direction from the wing root to the wing tip, the chord length and the attack angle of each airfoil section are smoothly transited along the trend of gradually increasing and then gradually decreasing.

Illustratively, the blade section 10 and the blade section 20 are provided with three airfoil sections for controlling the airfoil profile, when the airfoil sections are located at a first target spanwise position of the blade section, the chord length of the airfoil sections is 16% ± 1% of the radius of the propeller, the attack angle is 19.7 ° ± 0.1 °, and the distance between the first target spanwise position and the central axis of the central column is 20% ± 1% of the radius of the propeller; and/or when the airfoil section is located at a second target spanwise position of the blade section, the chord length of the airfoil section is 18% +/-1% of the radius of the propeller, the attack angle is 22.2 degrees +/-0.1%, and the distance between the second target spanwise position and the central axis of the central column is 27% +/-1% of the radius of the propeller; when the airfoil section is located at the third target spanwise position of the blade section, the chord length of the airfoil section is 11% + -1% of the radius of the propeller, the attack angle is 9.7 degrees +/-0.1%, and the distance between the third target spanwise position and the central axis of the central column is 80% + -1% of the radius of the propeller. In the embodiment of the present invention, the radius of the propeller refers to the distance between the blade and the central axis of the central column, for example, the radius of the propeller may be 1m or 2m, and in some embodiments, the radius of the propeller is not limited. Of course, it is understood that the location, chord length, and angle of attack of the airfoil section may have other suitable values, and fall within the scope of the present invention. Through experiments, the efficiency of the propeller with the two blades can be improved by more than 10% compared with that of a common propeller through the design.

In order to obtain the best lift coefficient, the wing profiles of the blade section 10 and the blade section 20 are concave-convex wing profiles. The concave-convex airfoil profile refers to an airfoil profile with a convex upper arc line and a concave lower arc line, and compared with other airfoil profiles, the concave-convex airfoil profile has the maximum lift coefficient, and meanwhile, the resistance coefficient is lower in a certain range. Therefore, the highest theoretical lift-drag ratio can be obtained under reasonable design. In addition, the blade using such a concave-convex airfoil is the lightest, and therefore, is advantageous in weight reduction. Illustratively, the operating speed range of the blade is 1200-1800rpm, and in the operating speed range, the drag coefficient is low and the theoretical lift-drag ratio is high. It is understood that the airfoil profile of the blade section may also be a plano-convex airfoil profile, a symmetrical airfoil profile, a biconvex airfoil profile and an S airfoil profile, and the airfoil profiles are various, and the airfoil profile capable of meeting the lift requirement is within the protection scope of the present invention.

In some embodiments, the shape of the airfoil controls the thickness of the blade section to increase and then decrease along the length of the chord of the blade section, the maximum thickness of the blade section being 7.28% ± 0.5% of the chord length of the respective chord, the maximum thickness of the blade section being located at a position corresponding to a first chord position of the chord which is 24.7% ± 0.5% of the chord length. It will be appreciated that the specific number of airfoil sections is not limited herein, and that the efficiency of a propeller having a pair of blades can be improved by more than 5% by the above design, since both the upper and lower airfoils are smooth transitions, and the maximum thickness and maximum camber are controlled, i.e. the airfoil shape can be controlled.

Further, along the length of the chord of the blade section, the blade section has a bend with a maximum bend of 5.49% ± 0.5% of the chord length of the respective chord, the maximum bend of the bend corresponding at the position of the blade section to a second chord position of the chord, the second chord position being 43.6% ± 0.5% of the chord length of the chord. The wing profile design can ensure the lift of the propeller.

The wing root positions of the two blade sections are the same along the height direction of the center post 40, or the wing root positions of the two blade sections are different along the height direction of the center post 40.

It should be noted that the root position of each blade segment refers to the position of the trace of the first leading edge of each blade segment in the center post. Referring to fig. 3a-3c, according to the normal use state of the propeller, the wing root of the blade segment 10 (the position of the first leading edge trace of the blade segment 10 in the central pillar) is higher than the wing root of the blade segment 20 (the position of the first leading edge trace of the blade segment 20 in the central pillar); referring to fig. 4a-4c, along the axial direction of the central pillar 40, according to the normal use state of the propeller, the height direction of the wing root of the blade segment 10 (the position of the first leading edge trace of the blade segment 10 on the central pillar) is consistent with the height direction of the wing root of the blade segment 20 (the position of the first leading edge trace of the blade segment 20 on the central pillar); still alternatively, referring to fig. 5a-5c, along the axis of the central pillar 40, the root of the blade segment 10 (the position of the first leading edge trace of the blade segment 10 in the central pillar) is lower than the root of the blade segment 20 (the position of the first leading edge trace of the blade segment 20 in the central pillar) according to the normal use state of the propeller. The arrangement modes of the wing root of the three blade sections 10 and the wing root of the blade section 20 on the central column 40 have high theoretical lift-drag ratio and low resistance coefficient.

In some embodiments, the paddles are integrally formed or removably attached to the center post 40. The connecting part between the paddle and the central column 40 can be smoothly transited by integrally forming the paddle and the central column 40 by using a machining process, and sudden change of shape is not easy to generate between the paddle and the central column 40, so that the configuration of the whole propeller is damaged, and the lift coefficient is further influenced. Illustratively, the blade is connected with the central column 40 by adopting a mortise-tenon structure, and the blade in the embodiment of the invention is a smooth transition curved surface, particularly a torsion structure at a wing tip transition part, so that the manufacturing process of the blade is more complicated, and the blade and the central column 40 can be manufactured separately by connecting the mortise-tenon structure, so that the process is relatively simpler. And through the connected mode of tenon fourth of twelve earthly branches structure, the root detachably of paddle fixes on center post 40, can also when a paddle in the screw damages, need not change whole screw, and only simply with the paddle that damages replace can, the cost is lower, also easy to operate. Simultaneously, the paddle root of paddle can link together through tenon fourth of twelve earthly branches structure with 40 clearance fit of center post for the paddle leaves certain surplus at high-speed rotatory in-process, is difficult for the rupture, and the reliability is higher.

In certain embodiments, the propeller comprises at least two paddles that are centrosymmetric about the center of the center post 40. It will be appreciated that the arrangement of the blades to ensure stability of the blades during high speed rotation is generally in pairs, and by way of example, the embodiment of the invention may be two blades arranged symmetrically about the center of the center post 40, and for optimum lift coefficient, may be 4 blades divided into two pairs, where the two blades in each pair are arranged symmetrically about the center of the center post 40. Still alternatively, the propeller is provided with 6, 8, 10 blades, etc. according to the actual lift needs. The propeller with a plurality of blades may be uniformly distributed or non-uniformly distributed, and taking a propeller with four blades as an example, the angles of the blades are distributed at 45 ° and 135 °, it is understood that the angles of the blades are not limited to the above angles, and the blades are not limited to four blades.

The embodiment of the invention also provides a power assembly which comprises the propeller in the technical scheme, wherein the propeller is in transmission connection with the driving piece, the driving piece can drive the central column to rotate, and then the central column drives the blades to rotate. Wherein, the driving member can be a motor, and in order to obtain the optimum lift coefficient and the minimum resistance in cooperation with the propeller, the rotation speed per minute of the motor at least comprises 1000-.

For specific function realization and effect of the power assembly provided by the embodiment of the invention, please refer to the description of the propeller, which is not repeated herein.

The embodiment of the invention also provides an aircraft, which comprises a fuselage and at least one power assembly, wherein the power assembly is connected with the fuselage of the aircraft. It is understood that the number of the power assemblies in the aircraft may be one, or may be multiple, and the specific number is not limited in some embodiments, and when the number of the power assemblies is multiple, the aircraft may include two, three, four, five, six, eight, ten, etc. numbers of the power assemblies. When the number of the power assemblies is multiple, when the aircraft is in a flying state, the rotating directions of propellers contained in the power assemblies are different, and the rotating direction of each power assembly is adjusted according to the subsequent flying state of the aircraft, so that different flying postures of the aircraft are obtained. In some embodiments, the propellers included in at least two of the power assemblies are coaxially mounted, and the propellers included in at least two of the power assemblies rotate in the same direction when the aircraft is in flight. The aircraft is provided with two coaxial propellers, namely an upper and lower double-propeller configuration. Through the double-propeller with the structure, the power of the motor can be fully utilized, and under the condition of the same electric quantity, the flight time of the aircraft can be prolonged, and the flight experience can be improved.

It is noted that embodiments of the present invention include various devices having various embodiments of the propeller of the present disclosure, including, for example, the following illustrative devices: aircraft, ships, fans, cooling devices, heating devices, automobile engines, air circulation devices, and the like.

In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to be the same embodiment/mode or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of illustration of the disclosure and are not intended to limit the scope of the disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and are still within the scope of the present disclosure.

Claims (17)

1. A propeller comprising a central post and at least two blades, a root of each blade being disposed on the central post, each blade having two blade sections and a tip transition section, the root of each blade section being connected to the central post, each blade section having a first leading edge facing into the wind and a first trailing edge opposite the first leading edge;

the wing tip transition section is a curved transition section, the wing tip transition section is provided with a second front edge and a second rear edge opposite to the second front edge, the first front edges of the two blade sections are in transition connection through the second front edge, the first rear edges of the two blade sections are in transition connection through the second rear edge, and the second front edge and the second rear edge are both arc-shaped edges;

between the first leading edges of the two blade segments, the two blade segments have a trajectory of the first leading edges that is a catenary.

2. The propeller of claim 1 wherein the edge line of the arcuate edge is a catenary line.

3. The propeller of claim 1 wherein the edge line spacing of the second leading edge from the second trailing edge is at least 18 mm.

4. The propeller of claim 1 wherein the maximum distance between the edge line of the second leading edge and the center post is a first distance, the maximum distance between the edge line of the second trailing edge and the center post is a second distance, the first distance is greater than the second distance, and the difference between the first distance and the second distance is 5mm ± 2 mm.

5. The propeller of claim 1 wherein each of said blade segments is a curved blade segment; wherein the content of the first and second substances,

the edge line of the first leading edge is continuous in curvature with the edge line of the second leading edge; and/or the edge line of the first trailing edge is continuous in curvature with the edge line of the second trailing edge.

6. The propeller of claim 1 wherein the shaft of the central post is a circular shaft; wherein the content of the first and second substances,

the trace of the first leading edge is tangent to the surface of the circular shaft.

7. The propeller of claim 6 wherein two of said blade segments have a trajectory of said first leading edge that forms an included angle of 45 ° ± 5 ° with a tangent to a surface of said circular shaft.

8. The propeller of any one of claims 1 to 6 wherein each of said blade sections has a plurality of airfoil sections distributed along a spanwise direction of said blade section; wherein the content of the first and second substances,

the chord length and/or the angle of attack of each airfoil section increases and then decreases from the root in the direction of deployment of the blade section.

9. The propeller of claim 8 wherein when the airfoil section is at a first target spanwise location of the blade section, the chord length of the airfoil section is 16% ± 1% of the radius of the propeller, the angle of attack is 19.7 ° ± 0.1 °, and the first target spanwise location is 20% ± 1% of the radius of the propeller from the central axis of the central post; and/or the presence of a gas in the gas,

when the airfoil section is located at a second target spanwise position of the blade section, the chord length of the airfoil section is 18% ± 1% of the radius of the propeller, the attack angle is 22.2 ° ± 0.1 °, and the distance between the second target spanwise position and the central axis of the central column is 27% ± 1% of the radius of the propeller;

when the airfoil section is located at a third target spanwise position of the blade section, the chord length of the airfoil section is 11% + -1% of the radius of the propeller, the attack angle is 9.7 degrees +/-0.1%, and the distance between the third target spanwise position and the central axis of the central column is 80% + -1% of the radius of the propeller.

10. The propeller of any one of claims 1 to 6 wherein the airfoil of at least one of the blade sections is one of a concave-convex airfoil, a plano-convex airfoil, a symmetrical airfoil, a biconvex airfoil, and an S airfoil.

11. The propeller of any one of claims 1 to 6 wherein the blade segments increase in thickness and decrease in thickness along the chord length of the blade segments,

the maximum thickness of the blade section is 7.28% + -0.5% of the chord length of the corresponding chord line along the length direction of the chord line of the blade section, the maximum thickness of the blade section is located at a position corresponding to a first chord line position of the chord line, and the first chord line position is 24.7% + -0.5% of the chord length of the chord line.

12. The propeller of claim 11 wherein along the chord length of the blade segment, the blade segment has a bend with a maximum bend of 5.49% ± 0.5% of the chord length of the respective chord, the maximum bend of the bend corresponding at the location of the blade segment to a second chord position of the chord, the second chord position being 43.6% ± 0.5% of the chord length of the chord.

13. The propeller of claim 1 wherein the root positions of the two blade segments are the same along the height of the center post or are different along the height of the center post.

14. The propeller of any one of claims 1 to 6 wherein the blades are integrally formed with or removably attached to the central post.

15. A power assembly comprising a drive member and a propeller as claimed in any one of claims 1 to 14, the propeller being drivingly connected to the drive member.

16. An aircraft comprising a fuselage and at least one power module according to claim 15, wherein the power module is provided in the fuselage.

17. The aircraft of claim 16, wherein said power assembly is plural in number; wherein the content of the first and second substances,

when the aircraft is in a flight state, the rotation directions of propellers contained in the power assemblies are different; or the like, or, alternatively,

at least two propellers contained by the power assembly are coaxially arranged, and when the aircraft is in a flying state, the rotating directions of the propellers contained by the at least two power assemblies are the same.

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