A tilting structure of a rotary-wing aircraft

Abstract

The present invention discloses a tilting structure for a rotary-wing aircraft, which comprises a driving unit and a tilting unit. The rear parts of the driving unit and the tilting unit are arranged in a cylindrical positioning tube in sequence along a straight line. The tilting unit includes: a lead screw disposed in the positioning tube and linearly connected to the driving unit; a straight push rod is screwed on the lead screw through a nut. The front end of the straight push rod extends out of the front end of the positioning tube and is connected to a rotary base through a rotary joint. The rotary base is hinged to the upper end of a front positioning seat located at the front end of the positioning tube through a first rotating shaft. Under the push of the straight push rod, the rotary base can rotate around the first rotating shaft between an unfolded state and a closed state. For the tilting structure of the rotary-wing aircraft of the present invention, the transmission mechanism has high transmission precision and wear resistance, overcoming the problem of poor stability caused by wear of the transmission mechanism in the prior art. For the rotary base of the present invention, the tilting angle can be accurately and conveniently controlled.

Description

Technical Field

[0001] The present invention relates to a tilting structure of a rotorcraft with vertical takeoff and landing and tilting flight functions, belonging to the technical field of rotorcrafts. Background Art

[0002] At present, vertical takeoff and landing drones have been widely used in aspects such as forest rescue and fire inspection. However, with the continuous expansion of the market application scenarios, higher requirements are put forward for the endurance and takeoff and landing capabilities against wind of drones.

[0003] Traditional drones mostly adopt the "N + 1" layout, that is, a combination of N lift motors and one thrust motor. During the climbing stage of the aircraft, N lift motors are used as the main motors to ensure the stability of the aircraft's attitude, yaw, roll, etc. However, in strong wind weather, it is easy to control the lift overshoot, so it cannot be well controlled in strong wind days. In addition, during the climbing and landing stages of the aircraft, the power consumption of N motors is relatively large, and the N rotors are useless during the cruise stage, with low weight utilization rate. Generally speaking, it is relatively power-consuming and has low load utilization rate.

[0004] In order to solve the limitations and problems of the above-mentioned traditional drones mostly adopting the "N + 1" layout, a rotorcraft that can tilt the rotor has emerged. When taking off, landing and hovering, the rotors are arranged horizontally; when switching to cruise horizontal flight, the rotors are turned to a vertical arrangement; thus, the thrust motor can be omitted, and each rotor can be fully utilized, thereby saving electricity and improving the load utilization rate.

[0005] For a tilt-rotor aircraft, the tilt mechanism is the key to achieving the reversal of the rotors. For example, Chinese Patent No. CN113443136A discloses a multi-link tilt mechanism for a tilt-rotor aircraft and its working method. The tilt mechanism includes a fixed seat, a drive unit, and a tilt unit disposed within the fuselage. There is a cabin provided on the fuselage, and the fixed seat is disposed on the top wall of the cabin. A rotor mechanism is also provided on the fuselage. The tilt unit is connected to the rotor mechanism through a support seat. Among them, the tilt unit includes a transmission member, a thrust member, and a tilt member. The drive unit is connected to the transmission member. The thrust member connects the drive unit and the support seat. The tilt member is connected to the thrust member and is also connected to the fixed seat and the support seat. The drive unit controls the transmission member to drive the thrust member to rotate, and the thrust member drives the tilt member to rotate along with the fixed seat to control the tilting movement of the rotor mechanism. Among them, the transmission member adopts a worm and worm gear transmission mechanism, and the thrust member and the tilt member are two sets of four-link structures, that is, the control of the tilt unit is achieved by the combined movement of the worm and worm gear driving the multi-link structure. Although the stability of this tilt mechanism is improved during the tilting process, as is well known, due to the wear of the worm and worm gear during long-term rapid reciprocating motion and the problem of maintaining accuracy, after being used for a period of time, a gap is generated between the worm and the worm gear. When the transmission accuracy cannot be guaranteed, the tilt mechanism cannot accurately maintain the required tilt angle. Due to the gap of the worm and worm gear, the tilt mechanism swings within a certain range (error gap) at this angle. Since the rotor is in high-speed operation, this swing forms a rapid jitter phenomenon, thus unable to maintain the stability of the tilting process, lifting, and flight process, and unable to ensure the reliability of long-term flight, which further reduces the overall service life of the unmanned aircraft. Therefore, this tilt mechanism cannot meet the requirements of aircraft safety and service life. Another problem it has is that since the tilting of the tilt mechanism is achieved through the tilting of two sets of four-link structures, the rotation of the support seat for installing the rotor is a curvilinear rotation in space, that is, it not only rotates but also undergoes displacement. Therefore, it increases the complexity of controlling the tilt angle. At the same time, due to the large number of components and heavy weight of the double four-link structure, it will increase the power consumption of the aircraft.

[0006] Based on the above-mentioned shortcomings of the existing tilt mechanisms for tilt-rotor aircraft, a tilt mechanism for a tilt-rotor aircraft that can stably control the tilting of the rotor in any flight state for a long time and whose tilt angle is easy to control has become the goal pursued by those skilled in the art. Summary of the Invention

[0007] The purpose of the present invention is to solve the problems in the existing tilt mechanisms of tilt-rotor aircraft, such as poor operating stability, poor long-term flight reliability, and thus reduced service life after the wear of the transmission mechanism, as well as the difficulty in accurately controlling the tilt angle.

[0008] To achieve the above-mentioned invention object, the technical solution of the present invention is as follows:

[0009] A tilting structure of a rotorcraft, which includes a driving unit and a tilting unit, and is characterized in that: the rear parts of the driving unit and the tilting unit are arranged in a cylindrical positioning tube in sequence along a straight line; the tilting unit includes:

[0010] A lead screw, the rear end of the lead screw is installed in the positioning tube through a rear end fixing seat, and the rear end of the lead screw is linearly connected with the driving unit;

[0011] A nut, screwed on the lead screw, and can make a linear motion under the drive of the lead screw;

[0012] A straight push rod, the rear end of the straight push rod is fixedly connected with the nut, and a blind hole for the lead screw to extend into from the rear end is provided in the center of the straight push rod;

[0013] A front end positioning seat, fixedly installed at the front end of the positioning tube, a central positioning hole for the straight push rod to pass through is provided in the middle of the front end positioning seat, the front end positioning seat has a cylindrical first extension part extending forward, the length of the upper part of the first extension part is longer than that of the lower part, and the front end face of the lower part is in the shape of an inclined surface with a longer upper part and a shorter lower part;

[0014] A rotating base, the rotating base includes a circular base plate at the front end and a second extension part extending backward from the base plate, which is cylindrical and has the same diameter as the first extension part, the upper end of the second extension part is a shorter upper extension part, and the end face of the lower extension part under the upper extension part is in the shape of an inclined surface with a shorter upper part and a longer lower part; the upper part of the rear end of the rotating base is hinged to the upper part of the front end of the front end positioning seat through a first rotating shaft;

[0015] A rotating joint, one end of the rotating joint is rotatably connected to the front end of the straight push rod, and the other end is rotatably connected to the rotating base, and is used to push the rotating base to rotate between an unfolded state and a closed state around the center of the first rotating shaft.

[0016] As a preferred solution, wherein, the lead screw is a ball screw, and the nut is a ball nut; or: the lead screw is a T-shaped lead screw, and the nut is a T-shaped nut. Using a ball screw and a ball nut, the transmission accuracy is high and the wear resistance is good. Using a T-shaped lead screw and a T-shaped nut, the transmission accuracy is high, and its wear resistance can be improved by applying grease.

[0017] As a preferred solution, wherein, when the rotating base is in the closed state, the rear end face of the second extension part coincides with the front end face of the first extension part, and the rotating base and the front end positioning seat enclose a cylindrical shape.

[0018] As a preferred solution, two rotating shaft mounting seats are provided at the upper part of the first extension portion, and a notch is formed between the two rotating shaft mounting seats. The first rotating shaft is rotatably arranged in the rotating shaft mounting hole of the rotating shaft mounting seat.

[0019] Inside the rotating base, near the upper extension portion, a first connecting ear that can be inserted into the notch is provided. The first connecting ear of the rotating base is connected to the first rotating shaft between the two rotating shaft mounting seats of the front-end positioning seat. A second connecting ear is further provided on the rotating base, and the second connecting ear is located at a position below the same vertical plane as the first connecting ear. The rotating joint is rotatably connected to the second connecting ear.

[0020] As a preferred solution, both the front and rear ends of the rotating joint are Y-shaped structures, and a second rotating shaft and a third rotating shaft are respectively provided at the Y-shaped structures at both ends. The second connecting ear and the connecting ear of the linear push rod are inserted into the middle gap of the two Y-shaped structures of the rotating joint and are connected to the second rotating shaft and the third rotating shaft together.

[0021] As a preferred solution, the driving unit includes a driving motor, a coupling, and a motor fixing seat. The rear end of the lead screw is linearly connected to the driving motor through the coupling. The driving motor is arranged in the positioning tube through the motor fixing seat. The motor fixing seat includes an annular frame whose outer diameter is adapted to the inner diameter of the positioning tube. The center of the annular frame is a circular positioning hole for installing the motor, and motor fixing holes are provided on the annular frame.

[0022] As a preferred solution, the rear-end fixing seat includes an annular bracket one whose outer diameter is adapted to the inner diameter of the positioning tube and a positioning sleeve one that is integrally connected to the annular bracket one. The center has a rear positioning hole for lead screw support and positioning. The rear end of the lead screw passes through the rear positioning hole and is butted against the coupling.

[0023] As a preferred solution, the rear end of the front-end positioning seat has an annular bracket two whose inner diameter is adapted to the inner diameter of the positioning tube. The annular bracket two is fixed in the positioning tube by screws. The middle of the annular bracket two has a positioning sleeve two that is integrally connected to the annular bracket two. The central positioning hole for supporting the linear push rod is located at the center of the positioning sleeve two.

[0024] As a preferred solution, the rear end of the linear push rod has a flange, and the flange is connected to the front end face of the nut by screws.

[0025] As a preferred solution, it further includes a guiding mechanism for enabling the straight push rod and the nut to perform linear motion under the drive of the lead screw; the guiding mechanism includes a guide rail, the guide rail is arranged between the front-end positioning seat and the rear-end fixed seat, and a slideway parallel to the lead screw and the straight push rod is in the middle of the guide rail;

[0026] A sliding member is arranged on the outer edge of the flange of the straight push rod, and the upper end of the sliding member extends into the slideway and is guided and positioned in the slideway.

[0027] As a preferred solution, the two ends of the guide rail are connected to the front-end positioning seat and the rear-end fixed seat; a chordal section is provided on the outer edge of the flange of the straight push rod, and the sliding member is arranged on the chordal section; the sliding member adopts a rolling bearing.

[0028] As a preferred solution, the motor fixing seat has a weight-reducing groove around the motor fixing hole; a first weight-reducing hole is provided on the first annular bracket of the rear-end fixed seat; a second weight-reducing hole is provided on the second annular bracket of the front-end positioning seat.

[0029] As a preferred solution, it further includes a self-locking unit for keeping the rotating base in a closed state when the rotating base is in the forward flight state, the self-locking unit includes an electronic damper, the electronic damper is installed at the rear end of the positioning tube, and the rear output shaft of the driving motor is connected to the electronic damper.

[0030] As a preferred solution, it further includes a displacement sensor for recording the displacement state of the straight push rod, and both ends of the displacement sensor are connected to the front-end positioning seat and the rear-end fixed seat; alternatively, it further includes an angle potentiometer for detecting the rotation angle of the rotating base, and the angle potentiometer is arranged between the rotating shaft mounting seat and the first rotating shaft.

[0031] By adopting the above technical solutions, the present invention arranges the rear parts of the driving unit and the tilting unit in sequence along a straight line in the positioning tube, making the overall installation more convenient. By using a lead screw and a nut as the transmission components of the driving unit, it has the advantages of high transmission accuracy, low wear, and long service life, thus effectively solving the problem that the transmission mechanism in the tilting mechanism of the existing rotary-wing aircraft is worn, resulting in poor stability and reduced service life. The straight push rod connected to the lead screw and the nut of the present invention drives the rotary joint to swing. By hinging the rotary base arranged at the front end to the upper end of the front positioning seat and pushing the rotary base to rotate through the rotary joint, the rotary base can be switched between two states: the retracted state (the rotor is in the vertical position) and the deployed state (the rotor is in the horizontal position). By arranging the driving unit, the lead screw, and the straight push rod in the tilting unit in a straight line at the bottom of the cylindrical positioning tube, it is convenient for the assembly of each part. At the same time, since the rotation of the rotary base is based on the rotation axis 1 between the rotary base itself and the front positioning seat, the rotary base does not move in position during rotation, that is, the rotation axis 1 provides a rotation reference for its tilting angle, making the control of the tilting angle easier and more convenient. At the same time, the straight push rod and the rotary joint in the tilting unit are thrust components. Compared with the thrust component structure composed of a double four-bar linkage in the tilting mechanism of the existing rotary-wing aircraft, its structure is simple, greatly reducing the number of parts. The overall mechanism is simpler, easier to install, and reduces the structural weight, thereby reducing flight resistance, increasing the endurance time of the unmanned aerial vehicle, and enhancing the wind resistance ability.

[0032] The present invention further uses a guiding mechanism to make the straight push rod and the nut move linearly under the drive of the lead screw. By arranging the guide rail of the guiding mechanism between the front positioning seat and the rear fixing seat, especially using a rolling bearing for the sliding part that is arranged on the outer edge of the flange of the straight push rod and slides in the guide rail, the frictional resistance between the sliding part and the guide rail is reduced, and the smoothness of the movement of the straight push rod is improved.

[0033] The present invention further sets a self-locking unit at the rear end of the driving motor, specifically using an electronic damper. The electronic damper belongs to the type of low damping when powered on and high damping when powered off. When the rotary base is in the retracted state, at this time, by powering off the driving motor, the electronic damper is in a high damping state, thus realizing the self-locking function. Since the electronic damper is adopted, when the rotary base is in the retracted state, that is, during horizontal flight, the driving motor can be powered off, thereby saving electric energy, increasing the forward flight time, and increasing the flight duration.

[0034] The present invention further provides a displacement sensor between the front positioning seat and the rear fixing seat for recording the displacement state of the linear push rod. According to the displacement and the movement amount of the rotary joint, the current angle of the rotary base can be calculated and determined. Alternatively, by directly providing an angle potentiometer at one place of the rotating shaft, the tilting angle of the rotary base can also be directly detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 、 2 is the longitudinal sectional view of a tilting structure of a rotorcraft according to the present invention Figure 1 、 Two ;

[0036] Figure 3 、 4 is the three-dimensional view of a tilting structure of a rotorcraft according to the present invention with some positioning tubes removed Figure 1 、Three-dimensional Figure 2 ;

[0037] Figure 5 is the three-dimensional view of the motor fixing seat of a tilting structure of a rotorcraft according to the present invention;

[0038] Figure 6 、 7 is the three-dimensional view and side view of the rear fixing seat of a tilting structure of a rotorcraft according to the present invention;

[0039] Figure 8 、 9 is the three-dimensional view and longitudinal sectional view of the linear push rod of a tilting structure of a rotorcraft according to the present invention;

[0040] Figure 10 、 11 、12 is the three-dimensional Figure 1 、Three-dimensional Figure 2 and longitudinal sectional view of the front positioning seat of a tilting structure of a rotorcraft according to the present invention;

[0041] Figure 13 、 14 is the three-dimensional view and side view of the rotary base of a tilting structure of a rotorcraft according to the present invention;

[0042] Figure 15 is the three-dimensional view of the guide rail of a tilting structure of a rotorcraft according to the present invention;

[0043] Figure 16 is the three-dimensional view of the positioning tube of a tilting structure of a rotorcraft according to the present invention;

[0044] Figure 17 is the side view of Embodiment 2 of a tilting structure of a rotorcraft according to the present invention;

[0045] Figure 18 It is a three-dimensional view of the first rotating shaft in the second embodiment of the present invention;

[0046] Figure 19 It is a schematic diagram of the angle potentiometer in the second embodiment of the present invention.

[0047] Explanation of reference numerals: Driving unit 1, driving motor 11, coupling 12, motor fixing base 13, annular frame 131, positioning hole 132, motor fixing hole 133, weight reduction groove 134, screw hole 135; Tilting unit 2, lead screw 21, nut 22, straight push rod 23, blind hole 231, flange 232, chordal section 233, straight push rod connecting ear 234, rotary joint 24, rear fixing base 25, annular bracket one 251, positioning sleeve one 252, rear positioning hole 253, guide rail mounting hole one 254, potentiometer mounting hole one 255, weight reduction hole one 256; Front-end positioning seat 26, central positioning hole 261, first extension 262, upper part 2621, lower part 2622, rotating shaft mounting seat 2623, notch 2624, rotating shaft mounting hole 2625, annular bracket two 263, positioning sleeve two 264, guide rail mounting hole two 265, potentiometer mounting hole two 266, weight reduction hole two 267; Rotating base 27, base plate 271, second extension 272, upper extension 2721, lower extension 2722; First connecting ear 273, second connecting ear 274; First rotating shaft 281, semi-circular shaft end 2811, second rotating shaft 282, third rotating shaft 283; Guiding mechanism 29, guide rail 291, slideway 292, sliding member 293; Positioning tube 3, electronic damper fixing hole 31, motor fixing base fixing hole 32, rear fixing base fixing hole 33, front-end positioning seat fixing hole 34; Self-locking unit 4, displacement sensor 51, angle potentiometer 52. Detailed implementation manners

[0048] The following will give a detailed example of the preferred embodiment of the present invention in conjunction with the accompanying drawings, but the protection scope of the present invention cannot be limited by this preferred embodiment.

[0049] Embodiment 1, referring to Figures 1-4 , the figure shows a tilting structure of a rotorcraft according to the present invention, which includes: a driving unit 1 and a tilting unit 2. The feature of the present invention is that the rear parts of the driving unit 1 and the tilting unit 2 are arranged in a cylindrical positioning tube 3 in sequence along a straight line;

[0050] The driving unit 1 includes a driving motor 11, a coupling 12 and a motor fixing base 13; the driving motor 11 is fixed in a cylindrical positioning tube 3 through the motor fixing base 13, and the front output shaft of the driving motor 11 is connected to the tilting unit 2 through the coupling 12; referring to Figure 5Specifically, the motor fixing seat 13 includes an annular frame 131, the outer diameter of the annular frame 131 is adapted to the inner diameter of the positioning tube 3, the outer edge of the annular frame 131 has a screw hole 135, the motor fixing seat 13 is fixed in the positioning tube 3 by fastening screws, the center of the annular frame 131 is a circular positioning hole 132, the positioning hole 132 is used to install the motor, and the annular frame 131 is provided with four motor fixing holes 133, and the fixing plate of the motor end face is fixed to the annular frame 131 by fastening screws;

[0051] See also Figures 1-4 The tilting unit 2 includes: a screw 21, a nut 22, a straight push rod 23, a rotating joint 24, a rear-end fixed seat 25, a front-end positioning seat 26, a rotating base 27 and a guide mechanism 29; in order to improve the transmission accuracy and wear resistance, the screw 21 and the nut 22 are ball screws and ball nuts. Obviously, T-type screws and T-type nuts can also be used to replace ball screws and ball nuts, which also have good transmission accuracy, and the lubrication is improved by applying grease to reduce wear. The screw 21, nut 22, straight push rod 23, rear-end fixed seat 25, and guide mechanism 29 are arranged in the positioning tube 3, the front-end positioning seat 26 is fixed at the front end of the positioning tube 3, and the upper end of the rotating base 27 can be rotatably connected to the upper end of the front-end positioning seat 26;

[0052] Specifically, the rear end of the screw rod 21 is installed in the positioning tube 3 through the rear end fixing seat 25, and the rear end of the screw rod 21 is linearly connected to the driving motor 11 through the coupling 12; see Figure 6 , 7 The rear end fixing seat 25 includes an annular bracket 251 whose outer diameter matches the inner diameter of the positioning tube 3 and a positioning sleeve 252 connected to the annular bracket 251 as a whole. The center of the positioning sleeve 252 has a rear positioning hole 253 for supporting and positioning the screw rod 21. The rear end of the screw rod 21 passes through the rear positioning hole 253 and docks with the coupling 12. The rear end fixing seat 25 provides positioning and support for the screw rod 21.

[0053] The nut 22 is screwed onto the screw rod 21 and can perform linear reciprocating motion under the drive of the screw rod 21;

[0054] See also Figure 8 , 9 The rear end of the push rod 23 is fixedly connected to the nut 22, and the rear end of the push rod 23 has a blind hole 231 for the screw rod 21 to extend into; thereby, the push rod 23 can be driven to perform linear reciprocating motion through the nut 22; specifically, the rear end of the push rod 23 has a flange 232, and the flange 232 is connected to the front end surface of the nut 22 by screws; the front end of the push rod has a push rod connecting ear 234,

[0055] The front-end positioning seat 26 is fixedly installed at the front end of the positioning tube 3. Refer to Figure 10 , 11 , 12. There is a central positioning hole 261 in the middle of the front-end positioning seat 26 for the straight push rod 23 to pass through, so as to provide support and positioning for the straight push rod 23. Specifically, the rear end of the front-end positioning seat 26 has an annular bracket two 263 adapted to the inner diameter of the positioning tube 3. The outer circumferences of the positioning tube 3 and the annular bracket two 263 have screw holes and are fixedly connected by screws. There is a positioning sleeve two 264 integrally connected with the annular bracket two 263 in the middle of the annular bracket two 263. The central positioning hole 261 is located at the center of the positioning sleeve two 264 for supporting the straight push rod 23;

[0056] The front-end positioning seat 26 has a first extension part 262 extending forward. The first extension part 262 is cylindrical. The length of the upper part 2621 of the first extension part 262 is longer than the length of the lower part 2622, and the front end face of the lower part 2622 is in the shape of an inclined plane with the upper part long and the lower part short. There are two rotating shaft mounting seats 2623 at the upper part 2621 of the first extension part 262. There is a notch 2624 between the two rotating shaft mounting seats 2623. The rotating shaft mounting seats have rotating shaft mounting holes 2625. The first rotating shaft 281 is preferably installed in the rotating shaft mounting hole 2625 through a bearing;

[0057] Refer to Figure 13 , 14, the upper end of the rotating base 27 is rotatably connected to the rotating shaft mounting seat 2623 of the front-end positioning seat 26. Specifically, the rotating base 27 includes a circular base plate 271 at the front end and a cylindrical second extension portion 272 extending backward from the base plate 271. The circular base plate 271 at the front end is used to mount the rotor of the aircraft, and the second extension portion 272 has the same diameter as the first extension portion 262. The upper end of the second extension portion 272 is a relatively short upper extension portion 2721, and the end face of the lower extension portion 2722 below the upper extension portion 2721 is in the shape of an inclined surface with a short upper part and a long lower part. When the rotating base 27 is in the retracted state, the end face of the lower extension portion 2722 coincides with the end face of the lower part 2622 of the first extension portion 262 of the front-end positioning seat 26, that is, the rotating base 27 and the front-end positioning seat 26 are just in a cylindrical closed state. In fact, it is also possible to be in a non-closed state. There is a first connecting ear 273 near the upper extension portion 2721 inside the rotating base 27. The first connecting ear 273 is adapted to the gap 2624 between the rotating shaft mounting seat 2623 of the front-end positioning seat 26. The first connecting ear 273 is connected to the first rotating shaft 281 and can rotate with the first rotating shaft 281. That is, the rotating base 27 is rotatably connected to the rotating shaft mounting seat 2623 of the front-end positioning seat 26 through the first connecting ear 273. A second connecting ear 274 is also provided on the rotating base 27. The second connecting ear 274 is located on the same vertical plane as the first connecting ear 273 and at a position below the adjacent first connecting ear 273.

[0058] See Figures 1-4 , one end of the rotary joint 24 is rotatably connected to the front end of the linear push rod 23, and the other end is rotatably connected to the second connecting ear 274 of the rotating base 27. Specifically, both the front and rear ends of the rotary joint 24 are in a Y-shaped structure. There are mounting holes on the Y-shaped structure. The second rotating shaft 282 and the third rotating shaft 283 can be rotatably arranged on the mounting holes on the Y-shaped structures at both ends, preferably through bearings. The second connecting ear 274 and the linear push rod connecting ear 234 of the linear push rod 23 are inserted into the middle gap of the Y-shaped structure and connected to the second rotating shaft 282 and the third rotating shaft 283. Under the push of the linear push rod 23, the rotating base 27 is driven by the rotary joint 24 to rotate around the center of the first rotating shaft 281, so that the rotating base 27 can be switched between a vertical position (retracted state) and a horizontal position (deployed state).

[0059] See Figure 1 , 2, 3, and 15, the guiding mechanism 29 is used to restrict the linear movement of the straight push rod 23 and the nut 22. The guiding mechanism 29 includes a guide rail 291, and the guide rail 291 is arranged between the front-end positioning seat 26 and the rear-end fixing seat 25. The guide rail 291 can be directly arranged on the inner wall of the positioning tube 3. Preferably, both ends of the guide rail 291 are fixedly connected to the front-end positioning seat 26 and the rear-end fixing seat 25, and are arranged on the front-end positioning seat 26 and the rear-end fixing seat 25, which can keep the inner wall of the positioning tube 3 with a smooth round hole, facilitating the installation and disassembly of each part; see Figure 6 , 11 , on the annular bracket one 251 of the rear-end fixing seat 25 and the annular bracket two 263 of the front-end positioning seat 26, there are respectively provided a guide rail mounting hole one 254 and a guide rail mounting hole two 265. The guide rail mounting hole one 254 and the guide rail mounting hole two 265 are adapted to the shapes of the two ends of the guide rail 291. The two ends of the guide rail 291 are inserted therein, and screw holes are provided on the outer circles of the annular bracket one 251 and the annular bracket two 263, and are locked to the screw holes 293 at both ends of the guide rail 291 through screws; there is a slideway 292 parallel to the lead screw 21 and the straight push rod 23 in the middle of the guide rail 291;

[0060] See Figure 8 , on the outer edge of the flange 232 of the straight push rod 23, preferably, there is a chordal section 233 at this outer edge, and a sliding member 293 is provided. The upper end of the sliding member 293 extends into the slideway 292. In order to reduce the friction of guiding, preferably, the sliding member 293 adopts a rolling bearing, and the rolling bearing rolls and positions in the slideway, which can reduce the frictional resistance and make the movement of the straight push rod 23 smoother.

[0061] See Figures 1-4 , a tilt structure of a rotorcraft according to the present invention further includes a displacement sensor 51. The displacement sensor 51 is preferably connected to the front-end positioning seat 26 and the rear-end fixing seat 25 at both ends. See Figure 6 , 11 , on the side of the annular bracket one 251 of the rear-end fixing seat 25 and the annular bracket two 263 of the front-end positioning seat 26 opposite to the guiding mechanism 29, there are respectively provided a potentiometer mounting hole one 255 and a potentiometer mounting hole two 266 for the two ends of the displacement sensor 51 to be inserted and locked by screws. The displacement sensor 5 is used to sense the horizontal movement amount of the straight push rod 23, and the rotation angle of the rotating base 27 can be obtained through calculation, that is, it is used to control the tilt angle of the rotating base 27.

[0062] See Figures 1-4, the tilt structure of the rotorcraft of the present invention further includes a self-locking unit 4, which is used to keep the rotary base 27 in a closed state when the rotary base 27 is in the forward flight state (the rotary base 27 is in the retracted state). The self-locking unit 4 is preferably an electronic damper, which is installed at the rear end of the positioning tube 3, and the rear output shaft of the drive motor 11 is connected to the electronic damper. The electronic damper has low damping when energized and high damping when de-energized. When the rotary base 27 is in the retracted state, the drive motor 11 is de-energized, and the electronic damper is in a high-damping state, so that the self-locking function can be realized.

[0063] See Figure 16 , the positioning tube 3 is in the shape of a cylindrical tube, and it is provided with four groups of fixing holes, namely the electronic damper fixing hole 31, the motor fixing seat fixing hole 32, the rear end fixing seat fixing hole 33, and the front end positioning seat fixing hole 34. The electronic damper, the motor fixing seat 13, the rear end fixing seat 25, and the front end positioning seat 26 are respectively fastened to the positioning tube 3 by screws.

[0064] See Figure 5 , 6 , 11. In order to reduce the weight, among them, the motor fixing seat 13 has a weight reduction groove 134 around the motor fixing hole 133; weight reduction holes 256 and 267 are respectively provided on the annular bracket 251 of the rear end fixing seat 25 and the annular bracket 263 of the front end positioning seat 26.

[0065] When the tilt structure of the wing aircraft of the present invention works, it is mainly divided into two working states: the rotary base 27 deployment state and the rotary base 27 closed state. As Figure 4 shown, when it is in the deployment state, the rotor is horizontally arranged, and the aircraft is in the state of vertical lift and hover; when it is in the closed state, the rotor is vertically arranged, and the aircraft is in the state of horizontal flight. When the rotary base 27 is in the deployment state, as Figure 1 , 2 , 3, 4 shown, the drive motor 11 drives the lead screw 21 to rotate. Under the limiting action of the guiding mechanism 29, the lead screw 21 drives the nut 22 and the straight push rod 23 to move linearly along the central positioning hole 261 of the front end positioning seat 26. The straight push rod 23 drives the rotary base 27 to rotate clockwise around the center of the rotation shaft 281 through the rotary joint 24, so that the rotary base 27 flips upward. The control command controls the rotation speed of the drive motor 11, and analyzes and processes the feedback data of the displacement sensor 5. Finally, the rotary base 27 reaches the specified angular position. At this time, the drive motor 11 is in the powered-on working state, and the drive motor 11 can control the rotary base 27 to remain in the deployment state. At the same time, the electronic damper of the self-locking unit 4 is in the low-damping state (the electronic damper has low damping when energized and high damping when de-energized).

[0066] When the rotating base 27 is in the closed state, as Figure 2 shown, the drive motor 11 drives the lead screw 21 to rotate reversely. Under the limiting action of the guiding mechanism 29, the lead screw 21 drives the nut 22 and the straight push rod 23 to move linearly along the central positioning hole 261 of the front-end positioning seat 26. The straight push rod 23 drives the rotating base 27 to rotate counterclockwise around the first rotating shaft 281 through the rotating joint 24, so that the rotating base 27 rotates back to the closed state. The control instruction controls the motor speed to analyze and process the feedback data of the displacement sensor 5. Finally, the rotating base 27 reaches the specified closed angle position. At this time, the drive motor 11 is powered off, and the electronic damper of the self-locking unit 4 is in a high damping state, making the tilting unit 2 in a self-locking state. At this time, for forward flight, the drive motor 11 does not work, and the electronic damper is used for self-locking, which can save electricity, thereby increasing the forward flight time, increasing the flight endurance, facilitating the forward flight operation of the UAV, and improving the forward flight performance of the UAV.

[0067] Embodiment 2, see Figures 17-19 , which shows another preferred embodiment of the present invention. The difference from the previous embodiment is that an angle potentiometer 52 is used to replace the displacement sensor 51. The angle potentiometer 52 is arranged on the first rotating shaft 281 of the front-end positioning seat 26. At the end of the first rotating shaft 281, there is a semi-circular shaft end 2811 adapted to the central hole of the angle potentiometer 52 for installing the inner ring of the angle potentiometer 52. The rotating shaft mounting seat 2623 has a hole adapted to the outer edge of the angle potentiometer 52 for installing the angle potentiometer 52. In this embodiment, the tilting angle of the rotating base can be directly detected.

[0068] The above description is illustrative rather than restrictive to the present invention. The present invention aims to provide a tilting structure for a rotorcraft. Those of ordinary skill in the art understand that without departing from the spirit and scope defined by the claims, many modifications, variations or equivalents can be made, for example: changing the installation positions of the guiding mechanism rail and the displacement sensor, setting them on the inner wall of the positioning tube, and not using a rolling bearing for the sliding part, etc., but all will fall within the protection scope of the present invention.

Claims

1. A tilting structure of a rotary-wing aircraft, comprising a drive unit (1) and a tilting unit (2), characterized in that: The rear parts of the driving unit (1) and the tilting unit (2) are arranged in a cylindrical positioning tube (3) in sequence along a straight line; the tilting unit (2) includes: a lead screw (21), the rear end of the lead screw (21) is installed in the positioning tube (3) through a rear end fixing seat (25), and the rear end of the lead screw (21) is linearly connected to the driving unit (1); a nut (22), screwed onto the lead screw (21), and can perform a linear motion under the drive of the lead screw (21); a straight push rod (23), the rear end of the straight push rod (23) is fixedly connected to the nut (22), and a blind hole (231) for the lead screw (21) to extend into from the rear end is provided at the center of the straight push rod (23); a front end positioning seat (26), fixedly installed at the front end of the positioning tube (3), a central positioning hole (261) for the straight push rod to pass through is provided in the middle of the front end positioning seat (26), the front end positioning seat (26) has a cylindrical first extension part (262) extending forward, the length of the upper part (2621) of the first extension part (262) is longer than the length of the lower part (2622), and the front end face of the lower part (2622) is in the shape of an inclined plane with the upper part long and the lower part short; a rotating base (27), the rotating base (27) includes a circular base plate (271) at the front end and a second extension part (272) extending backward from the base plate (271), being cylindrical and having the same diameter as the first extension part, the upper end of the second extension part (272) is a shorter upper extension part (2721), and the end face of the lower extension part (2722) below the upper extension part (2721) is in the shape of an inclined plane with the upper part short and the lower part long; the upper part of the rear end of the rotating base (27) is installed at the upper part of the front end of the front end positioning seat (26) through a rotating shaft one (281); a rotating joint (24), one end of the rotating joint (24) is rotatably connected to the front end of the straight push rod (23), and the other end is rotatably connected to the rotating base (27), and is used to push the rotating base (27) to rotate between an unfolded state and a closed state around the center of the rotating shaft one (281).

2. The tilting structure of a rotary-wing aircraft according to claim 1, wherein: The lead screw is a ball screw, and the nut is a ball nut; Or: the lead screw is a T-shaped lead screw, and the nut is a T-shaped nut.

3. The tilting structure of a rotorcraft according to claim 1, characterized in that: When the rotating base (27) is in the closed state, the rear end face of the second extension part (272) coincides with the front end face of the first extension part (262), and the rotating base (27) and the front end positioning seat (26) enclose a cylindrical shape.

4. The tilting structure of a rotorcraft according to claim 3, characterized in that: Two rotating shaft mounting seats (2623) are provided at the upper part of the first extension part (262), a notch (2624) is provided between the two rotating shaft mounting seats, and the rotating shaft one can be rotatably arranged in a rotating shaft mounting hole (2625) in the rotating shaft mounting seat; Inside the rotating base (27), near the upper extension part (2721), there is a first connecting ear (273) that can be inserted into the notch. A first rotating shaft (281) is connected between the first connecting ear (273) of the rotating base (27) and two rotating shaft mounting seats (2623) of the front-end positioning seat (26); a second connecting ear (274) is further provided on the rotating base (27), and the second connecting ear (274) is located at a position below the same vertical plane as the first connecting ear (273); the rotating joint (24) is rotatably connected to the second connecting ear (274).

5. The tilting structure of a rotorcraft according to claim 4, wherein: Both the front and rear ends of the rotating joint (24) are Y-shaped structures, and a second rotating shaft (282) and a third rotating shaft (283) are respectively provided at the Y-shaped structures at both ends; the second connecting ear (274) and the connecting ear (234) of the linear push rod (23) are inserted into the middle space of the two Y-shaped structures of the rotating joint (24) and are connected to the second rotating shaft (282) and the third rotating shaft (283).

6. The tilting structure of a rotorcraft according to claim 5, characterized in that: The driving unit (1) includes a driving motor (11), a coupling (12) and a motor fixing seat (13). The rear end of the lead screw (21) is linearly connected to the driving motor (11) through the coupling (12); the driving motor (11) is arranged in the positioning tube (3) through the motor fixing seat (13); the motor fixing seat (13) includes an annular frame (131) with an outer diameter adapted to the inner diameter of the positioning tube, a circular positioning hole (132) for installing the motor is in the center of the annular frame (131), and motor fixing holes (133) are provided on the annular frame.

7. A tilting structure of a rotary-wing aircraft according to claim 6, characterized in that: The rear-end fixing seat (25) includes an annular bracket one (251) with an outer diameter adapted to the inner diameter of the positioning tube (3) and a positioning sleeve one (252) integrated with the annular bracket one (251). A rear positioning hole (253) for lead screw support and positioning is in the center, and the rear end of the lead screw (21) passes through the rear positioning hole (253) to be docked with the coupling (12).

8. The tilting structure of a rotorcraft according to claim 7, characterized in that: The rear end of the front-end positioning seat (26) has an annular bracket two (263) with an outer diameter adapted to the inner diameter of the positioning tube (3). The annular bracket two (263) is fixed in the positioning tube (3) by screws. A positioning sleeve two (264) integrated with the annular bracket two (263) is in the middle of the annular bracket two (263), and the central positioning hole (261) for supporting the linear push rod (23) is located at the center of the positioning sleeve two (264).

9. A tilting structure of a rotary-wing aircraft according to any one of claims 1-8, characterized in that: The rear end of the linear push rod (23) has a flange (232), and the flange (232) is connected to the front end face of the nut (22) by screws.

10. The tilting structure of a rotorcraft according to claim 9, characterized in that: It further includes a guiding mechanism (29) for enabling the straight push rod (23) and the nut (22) to perform linear motion driven by the lead screw (21); the guiding mechanism (29) includes a guide rail (291), the guide rail (291) is arranged between the front end positioning seat (26) and the rear end fixing seat (25), and a slideway (292) parallel to the lead screw and the straight push rod is in the middle of the guide rail (291); A sliding member (293) is arranged on the outer edge of the flange (232) of the straight push rod (23), and the upper end of the sliding member (293) extends into the slideway (292) and is guided and positioned in the slideway (292).

11. The tilt structure of a rotary wing aircraft according to claim 10, characterized in that: Both ends of the guide rail (291) are connected to the front end positioning seat (26) and the rear end fixing seat (25); a chord section plane (233) is provided on the outer edge of the flange (232) of the straight push rod (23), and the sliding member (293) is arranged on the chord section plane (233); the sliding member (293) adopts a rolling bearing.

12. A tilting structure of a rotorcraft according to claim 8, characterized in that: The motor fixing seat (13) has a weight reduction groove (134) around the motor fixing hole (133); a first weight reduction hole (256) is provided on the first annular bracket (251) of the rear end fixing seat (25); a second weight reduction hole (267) is provided on the second annular bracket (263) of the front end positioning seat (26).

13. A tilting structure of a rotary-wing aircraft according to any one of claims 1-8, characterized in that: It further includes a self-locking unit (4) for keeping the rotary base (27) in a closed state when the rotary base (27) is in the forward flight state, the self-locking unit (4) includes an electronic damper, the electronic damper is installed at the rear end of the positioning tube (3), and the rear output shaft of the driving motor (11) is connected to the electronic damper.

14. A tilting structure of a rotary-wing aircraft according to any one of claims 1-8, characterized in that: It further includes a displacement sensor (51) for recording the displacement state of the straight push rod (23), both ends of the displacement sensor (51) are connected to the front end positioning seat (26) and the rear end fixing seat (25); alternatively, it further includes an angle potentiometer (52) for detecting the rotation angle of the rotary base (27), and the angle potentiometer (52) is arranged between the rotating shaft mounting seat (2623) and the first rotating shaft (281).

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