CN114872880B

CN114872880B - Tilt-rotor mechanism, folding structure and aircraft using shape memory material

Info

Publication number: CN114872880B
Application number: CN202210668852.2A
Authority: CN
Inventors: 鲜雨哲; 门小凡; 刘京奥; 丁俊杰; 廖璨; 苏时秀; 邹鸿生
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2024-07-16
Anticipated expiration: 2042-06-14
Also published as: CN114872880A

Abstract

The invention relates to a tiltrotor mechanism, a folding structure and an aircraft applying shape memory materials, wherein the tiltrotor mechanism comprises: a rotary drive mechanism, a tilting mechanism employing a shape memory material, and a rotor mechanism; the rotary driving mechanism and the tilting mechanism are connected with the rotor wing mechanism, and the invention adopts the shape memory material to realize the design of the tilting mechanism, thereby simplifying the structure of tilting the machine body in a longitudinal vertical plane.

Description

Tilt rotor mechanism, folding structure and aircraft using shape memory material

Technical Field

The invention relates to the technical field of aircraft design, in particular to a tilting rotor mechanism using a shape memory material, a folding structure and an aircraft.

Background

The tilting rotor craft is a novel relative craft which has the advantages of both fixed wings and multiple rotors, avoids the defects that the fixed wing craft cannot take off and land vertically, has complex structure, poor stability and the like, and the rotor craft has low flying efficiency, short endurance time and slow speed, can realize fast and efficient long endurance, vertical take off and land, fixed-point hovering and the like, and has great application prospect in the aspects of military and civil use. But is difficult to study due to the multi-disciplinary fields involved. The design difficulty of the mechanism mainly lies in different flight state transition schemes, and the existing solutions are realized by means of complex hydraulic driving and mechanical transmission structures. The flight state transition scheme comprises, but is not limited to, tilting of an aircraft and folding of wings.

Disclosure of Invention

In view of this, the present invention provides a tiltrotor mechanism, a folding structure, and an aircraft employing shape memory materials to simplify the structure required for transition from the state of flight of the tiltrotor aircraft.

In order to achieve the above object, the present invention provides the following solutions:

A tiltrotor mechanism employing shape memory material, the tiltrotor mechanism comprising: a rotary drive mechanism, a tilting mechanism employing a shape memory material, and a rotor mechanism;

the rotary driving mechanism and the tilting mechanism are connected with the rotor wing mechanism.

Optionally, the rotary driving mechanism comprises a driving motor, a first cylindrical gear, a second cylindrical gear, a transmission shaft and a first bevel gear;

an output shaft of the driving motor is connected with the first cylindrical gear;

one end of the transmission shaft is connected with the second cylindrical gear, and the other end of the transmission shaft is connected with the first bevel gear;

The first spur gear is meshed with the second spur gear, and the first bevel gear is meshed with the second bevel gear of the rotor mechanism.

Optionally, the tilting mechanism includes a tilting shaft cylinder and a tilting SMA (Shape Memory Alloy, shape memory material) coil spring;

The rotation driving mechanism is arranged in the tilting shaft cylinder;

one end of the tilting shaft cylinder is fixedly connected with a box section for fixing the rotor wing mechanism;

the outer side of the other end of the tilting shaft cylinder is fixedly connected with the inner folded end of the tilting SMA coil spring;

the outward folding end of the tilting SMA coil spring is fixedly connected with the inner side of a boss of a fixed sleeve arranged on the aircraft;

When the tilting SMA coil spring is electrified, the tilting SMA coil spring is contracted and screwed to drive the tilting shaft cylinder to rotate, so that the rotor wing mechanism is driven to tilt.

Optionally, a first bearing is further arranged between the outer side of the other end of the tilting shaft cylinder and the part of the fixed sleeve, which is not provided with the tilting SMA coil spring;

the first bearing is used for supporting the tilting shaft cylinder.

Optionally, the fixing sleeve is provided with a vent hole.

Optionally, a limiting groove is formed in the fixed sleeve, and a limiting shaft shoulder is arranged on the tilting shaft cylinder; the limiting shaft shoulder can move in a range limited by the limiting groove.

Optionally, the tiltrotor mechanism further comprises at least one support disc and at least one second bearing;

the transmission shaft is supported on the supporting disc through the second bearing, and the supporting disc is fixed inside the tilting shaft cylinder.

Optionally, the number of the rotary driving mechanism, the tilting mechanism and the rotor wing mechanism is two;

the two rotor wing mechanisms are respectively an upper rotor wing mechanism and a lower rotor wing mechanism;

The rotary main shaft of the upper rotor wing mechanism penetrates into the box section from the upper surface of the box section and is connected with the upper surface of the box section through a brake bearing;

the rotary main shaft of the lower rotor wing mechanism penetrates into the box section from the lower surface of the box section and is connected with the lower surface of the box section through a brake bearing;

the second bevel gears are arranged at the tail ends of the rotating main shaft of the upper rotor wing mechanism and the rotating main shaft of the lower rotor wing mechanism;

The two rotary driving mechanisms are respectively arranged at the left side and the right side of the box section;

the first bevel gears of the two rotary driving mechanisms are respectively meshed with the second bevel gears arranged at the tail ends of the rotary main shaft of the upper rotor wing mechanism and the rotary main shaft of the lower rotor wing mechanism;

one ends of the tilting shaft barrels of the two tilting mechanisms are respectively connected with the left side and the right side of the box section.

A folded structure employing a shape memory material, the folded structure comprising: the device comprises at least two supporting frames, a fixed shaft, at least two folding SMA coil springs and at least two sleeve connecting pieces;

the support frame is fixedly connected with the fixed shaft;

the inward folding end of the folding SMA coil spring is fixedly connected with the outer surface of the fixed shaft;

the outward folding end of the folding SMA coil spring is fixedly connected with the inner surface of the sleeve connecting piece;

A third bearing is arranged at the part between the fixed shaft and the sleeve connecting piece, which is not provided with the folding SMA coil spring;

the supporting frame and the sleeve connecting piece are also respectively connected with two structures to be folded;

when the folding SMA coil springs are electrified, the folding SMA coil springs shrink and screw to drive the fixed shafts to rotate, so that the two structures to be folded are folded.

A tiltrotor aircraft employing shape memory materials, said aircraft comprising a fuselage, a left wing, a right wing, and said tiltrotor mechanism;

a through hole is formed in the center of the machine body, and a fixed sleeve is arranged in the through hole; the tilting rotor mechanism is arranged in the fixed sleeve;

the left wing and the right wing comprise wing roots, wing neutralization wing tips which are sequentially connected through flexible transition sections;

The folding structures are arranged between the wing root and the wing, and between the wing and the wing tip.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

The invention discloses a tilting rotor mechanism, a folding structure and an aircraft applying shape memory materials, wherein the tilting rotor mechanism comprises: a rotary drive mechanism, a tilting mechanism employing a shape memory material, and a rotor mechanism; the rotary driving mechanism and the tilting mechanism are connected with the rotor wing mechanism, and the invention adopts the shape memory material to realize the design of the tilting mechanism, thereby simplifying the structure of tilting the machine body in a longitudinal vertical plane.

The folding structure comprises at least two supporting frames, a fixed shaft, at least two folding SMA coil springs and at least two sleeve connecting pieces; the support frame is fixedly connected with the fixed shaft; the inward folding end of the folding SMA coil spring is fixedly connected with the outer surface of the fixed shaft; the outward folding end of the folding SMA coil spring is fixedly connected with the inner surface of the sleeve connecting piece; a third bearing is arranged at the part between the fixed shaft and the sleeve connecting piece, which is not provided with the folding SMA coil spring; the supporting frame and the sleeve connecting piece are also respectively connected with two structures to be folded; when the folding SMA coil springs are electrified, the folding SMA coil springs shrink and screw to drive the fixed shafts to rotate, so that the two structures to be folded are folded. The invention adopts shape memory material (folding SMA coil spring) to realize the design of folding structure, and simplifies the structure for folding the wing.

According to the aircraft, the tilting rotor wing mechanism with the shape memory material can tilt between the horizontal position and the vertical position, so that the aircraft can be switched between the vertical take-off and landing state and the rapid forward flight state; the folding structure of the shape memory material can be used for folding the wing tip and the wing, so that the induced resistance can be reduced, the problem of lift redundancy during rapid forward flight can be solved, and the aircraft has good aerodynamic characteristics under the working conditions of high speed and low speed; the tilting rotor wing mechanism and the folding mechanism are driven by coil spring type SMA, and have the advantages of large driving force and simple driving structure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a vertical take-off and landing mode of a tiltrotor aircraft using a shape memory material according to embodiment 1 of the present invention;

FIG. 2 is a schematic view of a fast fly-flat mode of a tiltrotor aircraft employing shape memory materials according to embodiment 1 of the present invention;

fig. 3 is a schematic structural diagram of a rotary driving mechanism according to embodiment 1 of the present invention;

Fig. 4 is a schematic structural diagram of a tilting mechanism according to embodiment 1 of the present invention;

Fig. 5 is a schematic diagram illustrating a limiting relationship between the tilting shaft barrel and the fixing sleeve according to embodiment 1 of the present invention;

FIG. 6 is a schematic diagram showing the assembly relationship of parts on a tilting shaft according to embodiment 1 of the present invention;

FIG. 7 is a schematic diagram showing the positional relationship of a tilting SMA coil spring and its heating wires according to embodiment 1 of the present invention;

Fig. 8 is a schematic structural view of the folding mechanism in a flat state according to embodiment 1 of the present invention;

Fig. 9 is a schematic structural view of the folding mechanism provided in embodiment 1 of the present invention in a folded state;

Wherein 1-fuselage, 2-wing, 3-tilting rotor mechanism, 4-folding mechanism, 5-V-tail, 6-thrust rotor, 21-wing root, 22-wing, 23-wing tip, 24-flexible transition section, 311-drive motor, 312-first cylindrical gear, 313-second cylindrical gear, 314-drive shaft, 315-rotating main shaft, 316-axial stop bearing, 317-tilting rotor, 321-fixed sleeve, 3211-boss, 3212-vent, 3213-limit slot, 322-tilting SMA coil spring, 3221-tilting SMA coil spring fold-out end, 3222-tilting SMA coil spring fold-in end, 3223-heating wire negative electrode, 3224-heating wire positive electrode, 323-tilting shaft barrel, 3231-limit shaft shoulder, 324-first bearing, 325-support disc, 326-second bearing 327-box section, 41-support frame, 42-fixed shaft, 43-folding SMA, 44-third bearing, 45-sleeve connector.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on embodiments of the present invention, are intended to be within the scope of the present invention.

The invention aims to provide a tilting rotor mechanism, a folding structure and an aircraft, which use shape memory materials, so as to simplify the structure required by the transition of the flight state of the tilting rotor aircraft.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

In the description of the present embodiment, it should be understood that the terms "center", "front", "inner", "horizontal", "vertical", "clockwise", "both sides", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and each "axial" is defined based on the currently set forth components, rather than implying or indicating an orientation or position that the components must have, and therefore should not be construed as limiting the scope of the present invention.

Example 1

Embodiment 1 of the present invention provides a tiltrotor aircraft using shape memory materials, as shown in fig. 1-2, the present embodiment is an aileron+v-tail layout, comprising a fuselage 1, a tiltrotor mechanism 3, a V-tail 5, a propulsive rotor 6, and a folding structure 4; tilt rotor mechanism 3 includes rotary drive mechanism, application shape memory material's tilt mechanism and rotor mechanism, and rotary drive mechanism includes driving motor 311, first cylindrical gear 312, second cylindrical gear 313, transmission shaft 314 and first bevel gear, and tilt mechanism includes tilt shaft section 323 and tilting SMA coil spring 322, and rotor mechanism includes tilt rotor 317. The folding structure 4 includes: a support bracket 41, a fixed shaft 42, a folding SMA coil spring 43, and a sleeve connection 44; the flying wing type aerodynamic layout has the advantage of large lift force, and can generate enough lift force at a lower speed, so that the power requirement on the propelling rotor wing (6) is small. The center of the fuselage 1 is provided with a through hole, and the tilting rotor mechanism 3 is arranged in the through hole, so that rotor airflow is not disturbed when the helicopter is lifted vertically, and the flying wing type layout fuselage is thinner, and rotor airflow disturbance is weak when the helicopter is flown forward. The tail part of the machine body 1 is provided with a V-tail 5, and an operating control surface is arranged on the V-tail for controlling the attitude of the aircraft.

As shown in fig. 1-2, the front part of the fuselage 1 of the present embodiment is provided with a propulsion rotor 6 which is vertical with two rotor planes, and provides thrust when the vertical take-off and landing mode is transitioned to the forward flight mode and the forward flight mode.

As shown in fig. 1-2, tilt rotor 317 in the center of fuselage 1 of the present embodiment remains horizontal during the vertical take-off and landing and transition modes and tilts to a vertical position during the forward flight mode.

1-2, The wing 2 of the embodiment is divided into three sections, namely a wing root 21, a wing middle 22 and a wing tip 23, the two sections are connected through a folding mechanism 4, folding in a certain angle can be achieved, and the folding mechanisms 4 of the wings 2 on two sides can be controlled differentially. In the embodiment, when the aircraft flies forward at a low speed, the wing tips 23 are folded and the wings 22 are flattened, so that the induced resistance is reduced; when the aircraft flies fast forward, the wing tip 23 and the wing middle 22 are folded, so that the projection area of the lifting force is reduced.

As shown in fig. 3, the rotary drive mechanism in the tiltrotor mechanism 3 has a structure in which: the driving motor 311 drives the first cylindrical gear 312 to rotate, the first cylindrical gear 312 transmits the rotary motion to the second cylindrical gear 313, the second cylindrical gear 313 is fixedly connected with the transmission shaft 314, the output end of the transmission shaft 314 is a first bevel gear, the transmission shaft 314 is meshed with a second bevel gear of a rotary main shaft 315 of the rotor mechanism, the rotary main shaft 315 is fixedly connected with the tilting rotor 317, and the tilting rotor 317 is driven to rotate. It is noted that upper and lower tiltrotors 317 are each driven by rotary drive mechanisms located on the left and right sides of fuselage 1, and are capable of independently controlling rotational speed, thereby controlling yaw of the aircraft.

As shown in fig. 3, the support disk 325 is a circular disk having an eccentric through hole.

As shown in fig. 3, the transmission shaft 314 is supported on a support disc 325 through a second bearing 326, the support disc 325 is fixed inside the tilting shaft cylinder 323, and an exemplary one tilting shaft cylinder 323 has two second bearings 326 and support disc 325 combined in the axial direction to improve structural rigidity; rotating main shaft 315 is coupled to box section 327 by axial stop bearing 316 and has an axial positioning function to carry the aerodynamic forces provided by tiltrotor 317.

As shown in fig. 4, fixing sleeve 321 has a protruding boss 3211, the square structure of which facilitates installation of tilting SMA coil spring 322 in the tilting mechanism, the outer end of tilting SMA coil spring 322 is fixed in boss 3211, the inner end of tilting SMA coil spring 322 is fixed on tilting shaft cylinder 323, when heating wire positive electrode 3224 and heating wire negative electrode 3223 are energized, tilting SMA coil spring 322 is heated, contracted and screwed, thereby driving tilting shaft cylinder 323 to rotate clockwise.

As shown in fig. 4, fixed sleeve 321 is further provided with a vent hole 3212 to allow the spanwise air flow generated during rotation of tilt rotor 317 to enter the inner cavity of fixed sleeve 321 for timely cooling of tilt SMA coil spring 322.

As shown in fig. 5, fixing sleeve 321 is further provided with a limiting groove 3213, and tilting shaft barrel 323 is further provided with a limiting shoulder 3231, wherein limiting shoulder 3231 can only rotate in limiting groove 3213, so that two limiting angles of tilting shaft barrel 323 rotating in fixing sleeve 321 are limited, and two limiting positions of tilting rotor 317 are limited.

As shown in fig. 6, tilt shaft cylinder 323 is axially mounted with a tilt SMA coil spring 322 and a first bearing 324, respectively, first bearing 324 supporting tilt shaft cylinder 323 within fixed sleeve 321, tilt SMA coil spring 322 providing a driving force for rotation of tilt shaft cylinder 323.

As shown in fig. 7, two ends of the tilting SMA coil spring 322 are respectively folded for a certain distance to form a tilting SMA coil spring folded-out end 3221 and a tilting SMA coil spring folded-in end 3222, which are respectively embedded into the fixed sleeve 321 and the tilting shaft barrel 323 to realize fixed connection; heating wire negative electrode 3223 is buried in the inner cavity of fixed sleeve 321, heating wire positive electrode 3224 stretches out tilting shaft barrel 323 and is buried in fuselage 1, and tilting SMA coil spring outer folding end 3221 and tilting SMA coil spring inner folding end 3222 are respectively connected, and heating current is controlled by an aircraft control system, so that control over the driving angle of tilting SMA coil spring 322 is realized.

As shown in FIG. 7, the surface of tilt SMA coil spring 322 is also coated with a layer of heating material to uniformly heat the entire tilt SMA coil spring 322.

As shown in fig. 3 to 7, upper and lower tiltrotors 317 are driven in tilting angles by tilting mechanisms disposed on the left and right sides of the body 1, respectively. The tilting mechanisms on the left and right sides control tilting in opposite directions, that is, the directions of screwing the SMA coil springs 322 on both sides are opposite when heated, the eccentric through holes on the supporting discs 325 on both sides are symmetrical about the axis, and the transmission shafts 314 on both sides are symmetrical about the axis of the tilting shaft barrel 323, so that the upper and lower rotary spindles 315 are axially spaced apart by a certain distance, so that the transmissions on both sides do not interfere with each other.

As shown in fig. 8-9, the wing 22 and the wing tip 23 are connected by a flexible transition section 24, the surface of the flexible transition section 24 is made of a high-flexibility material, so that continuous and complete aerodynamic appearance is ensured when the wing tip 23 is folded up and put down, and the function is particularly critical when the wing tip 23 is folded up. Inside the flexible transition 24, a pair of support brackets 41 positioned chordwise near the middle are fixedly attached to the outer surface of the wing 22, noting that the internal configuration of the wing 22 is not solid, so in practice the support brackets 41 are fixedly attached to some foundation that has been thickened. The fixed shaft 42 is fixedly connected with the support 41, and two ends of the fixed shaft 42 are respectively and fixedly connected with the inner folding ends of the folding SMA coil springs 43. The surface of the fixed shaft 42 beside the folded SMA coil spring 43 is fixedly connected to the sleeve connection 45 via the third bearing 44, the sleeve connection 45 being fixedly connected to the wing tip 23. Wherein folded SMA coil spring 43 heats in a manner similar to that of tilting SMA coil spring 322.

Finally, it should be pointed out that: the foregoing detailed description is a detailed description of the technical solution and advantageous effects of the present invention, and the foregoing detailed embodiments are used for explaining the embodiments, but should not be construed as limiting the scope of the present invention, and any modification, reduction, replacement, rearrangement, etc. made on the basis of the technology of the present invention fall within the scope of the present invention.

Example 2

Embodiment 2 of the present invention provides a tiltrotor mechanism according to embodiment 1.

Example 3

Embodiment 3 of the present invention provides a folded structure in embodiment 1.

Based on the above embodiments, the advantages of the present invention are as follows:

1. Through the central rotor wing, the aircraft can tilt between the horizontal position and the vertical position, so that the aircraft can be switched between the vertical take-off and landing state and the rapid forward flight state.

2. The wing tip winglets can be respectively folded through the wing tip sections at the two sides, so that the problem of lift redundancy during rapid forward flight can be solved, meanwhile, the induced resistance is reduced, the aircraft has good aerodynamic characteristics under the working condition of high speed and low speed, and the maneuverability of the aircraft can be improved through differential control of the wing tips at the two sides.

3. The coil spring type shape memory alloy is used for driving the tilting mechanism and the wing tip folding mechanism, so that the driving force is high, the defect of small deformation of the shape memory alloy is overcome, the whole driving mechanism is very concise, the structure is light, and the tilting mechanism is very suitable for small and medium-sized tilting rotor craft.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, as will occur to those of ordinary skill in the art, many modifications are possible in view of the teachings of the present invention, both in its specific embodiments and its application scope. In view of the foregoing, this description should not be construed as limiting the invention.

Claims

1. A tiltrotor mechanism employing shape memory material, the tiltrotor mechanism comprising: a rotary drive mechanism, a tilting mechanism employing a shape memory material, and a rotor mechanism;

the rotary driving mechanism and the tilting mechanism are connected with the rotor wing mechanism;

the rotary driving mechanism comprises a driving motor, a first cylindrical gear, a second cylindrical gear, a transmission shaft and a first bevel gear;

the first cylindrical gear is meshed with the second cylindrical gear, and the first bevel gear is meshed with the second bevel gear of the rotor mechanism;

the tilting mechanism comprises a tilting shaft cylinder and a tilting SMA coil spring;

The rotation driving mechanism is arranged in the tilting shaft cylinder;

When the tilting SMA coil spring is electrified, the tilting SMA coil spring is contracted and screwed to drive the tilting shaft cylinder to rotate, so that the rotor wing mechanism is driven to tilt;

the number of the rotary driving mechanism, the tilting mechanism and the rotor wing mechanism is two;

2. The tiltrotor mechanism employing shape memory material according to claim 1, wherein a portion between the outside of the other end of the tiltrotor shaft and the stationary sleeve where no tilt SMA coil spring is disposed is further provided with a first bearing;

the first bearing is used for supporting the tilting shaft cylinder.

3. The tiltrotor mechanism employing shape memory material according to claim 1, wherein the stationary sleeve is provided with a vent hole.

4. The tiltrotor mechanism employing shape memory material according to claim 1, wherein the fixed sleeve is provided with a limit groove, and the tiltrotor shaft is provided with a limit shoulder; the limiting shaft shoulder can move in a range limited by the limiting groove.

5. The tiltrotor mechanism employing shape memory material according to claim 1, wherein the tiltrotor mechanism further comprises at least one support disk and at least one second bearing;

6. A tiltrotor aircraft employing shape memory materials, comprising: fuselage, left wing, right wing and tiltrotor mechanism according to any of claims 1-5;

folding structures are arranged between the wing root and the wing, and between the wing and the wing tip.

7. The tiltrotor aircraft employing shape memory material according to claim 6, wherein the folding structure comprises: the device comprises at least two supporting frames, a fixed shaft, at least two folding SMA coil springs and at least two sleeve connecting pieces;

the support frame is fixedly connected with the fixed shaft;