Single power transmission system, unmanned aerial vehicle and control method

Abstract

The present invention provides a single power transmission system, a UAV and a control method, wherein the single power transmission system comprises an engine unit, a main gearbox drivingly connected to the engine unit, and a propeller; the main gearbox comprises a first main output shaft and two second main output shafts symmetrically arranged on both sides of the first main output shaft, the first main output shaft is drivingly connected to the propeller through a first reversing gearbox; the two second main output shafts are drivingly connected to a tilt-rotor integrated module through corresponding reduction gearboxes respectively; the present invention has high power integration, high aerodynamic quality and high reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles, and in particular to a single power transmission system, an unmanned aerial vehicle and a control method. Background Art

[0002] Existing tilt-rotor UAVs mainly adopt the form of full tilt or partial tilt.

[0003] There are two types of power methods for fully tilting UAVs: a distributed power layout. This type of UAV has many power units, and all power units are required to have high reliability, making it difficult to obtain airworthiness certification. Another type is to directly use a servo motor to drive the worm gear and reducer to tilt all rotors. In this type, if a rotor device fails, the UAV cannot smoothly complete the transition flight conversion, and the UAV cannot ensure safe landing. In addition, the power source of the tilting mechanism is independent of the rotor rotation energy, and the integration is not high.

[0004] The partial tilt form mostly uses the front and rear rotors to tilt the fuselage, while the built-in rotors in the wings do not tilt to achieve vertical take-off and landing and level flight. The design of these built-in rotors in the wings has a great impact on the integrity of the wing aerodynamic surface. During level flight, the rotors inside the wings will generate great resistance, resulting in extremely poor aerodynamic quality of the drone.

[0005] Therefore, there is an urgent need for a single power transmission system, a UAV and a control method with high power integration, high aerodynamic quality and high reliability. Summary of the invention

[0006] The purpose of the present invention is to provide a single power transmission system, a UAV and a control method, aiming to solve the technical problems of low power integration, poor aerodynamic quality and low reliability of traditional tilt-rotor UAVs.

[0007] To achieve the above-mentioned object, in a first aspect, the present invention provides a single power transmission system, comprising an engine unit, a main gearbox drivingly connected to the engine unit, and a propeller;

[0008] The main gearbox comprises a first main output shaft and two second main output shafts symmetrically arranged on both sides of the first main output shaft.

[0009] The first main output shaft is drivingly connected to the propeller through a first reversing gear box;

[0010] The two second main output shafts are respectively driven and connected to the tilt-rotor integrated module through corresponding reduction gear boxes.

[0011] As a further improvement of the above solution, the tilt-rotor integrated module includes a sub-gearbox drivingly connected to the reduction gearbox, a tilt unit and a main rotor unit drivingly connected to the sub-gearbox;

[0012] The main rotor unit comprises a main rotor gearbox and a rotor connected to an output shaft of the main rotor gearbox; the auxiliary gearbox is drivingly connected to the main rotor gearbox via a universal joint;

[0013] The tilting unit includes a worm and a turbine meshing with the worm, the auxiliary gear box is drivingly connected to the worm through a clutch, and a second reversing gear box is further provided between the auxiliary gear box and the clutch;

[0014] The main rotor gearbox is arranged on the turbine, and the rotating shaft of the turbine is coaxially arranged with a rotating shaft on one side of the universal joint, so that the worm drives the turbine to rotate around the center of the universal joint to realize the preset tilt angle of the rotor.

[0015] As a further improvement of the above solution, the auxiliary gearbox includes a first auxiliary output shaft and a second auxiliary output shaft, and the first auxiliary output shaft is drivingly connected to the worm through the clutch;

[0016] The second secondary output shaft is drivingly connected to the main rotor gearbox via the universal joint.

[0017] As a further improvement of the above solution, the main rotor gearbox includes a first rotor shaft, a first bevel gear arranged on the first rotor shaft, a second rotor shaft, and a second bevel gear arranged on the second rotor shaft, the first rotor shaft and the second rotor shaft are arranged perpendicular to each other, and the first bevel gear and the second bevel gear are meshed and connected;

[0018] The turbine is rotatably arranged on the first rotor shaft, and the end of the first rotor shaft away from the first bevel gear is connected to the universal joint;

[0019] The end of the second rotor shaft away from the second bevel gear passes through the turbine and is connected to the rotor.

[0020] As a further improvement of the above scheme, the first reversing gear box and the second reversing gear box have the same structure; they respectively include a driving gear, a driven gear, a first idler gear and a second idler gear; a first connecting rod is provided between the first idler gear and the second idler gear, and a second connecting rod is provided between the driven gear and the second idler gear;

[0021] In the first state, the driving gear is meshed and driven with the driven gear through the first idler gear and the second idler gear in sequence;

[0022] In the second state, the driving gear is meshed and transmitted with the driven gear through the second idler gear.

[0023] As a further improvement of the above scheme, the first reversing gear box and the second reversing gear box also respectively include a connecting rod driving mechanism for driving the second connecting rod and the first connecting rod to swing so as to swing the first idler gear and / or the second idler gear between the driving gear and the driven gear.

[0024] In a second aspect, the present invention further provides a drone, comprising a fuselage and a single power transmission system as provided in the first aspect and arranged in the fuselage; the fuselage comprises a fuselage body and a tail wing arranged at the tail of the fuselage body, and a left wing and a right wing symmetrically arranged on both sides of the fuselage body;

[0025] The engine unit is arranged at the fuselage body close to the center of gravity of the whole machine, the first reversing gearbox is arranged at the fuselage body close to the nose, the propeller is arranged at the nose, and the main gearbox is arranged at the intersection of the wings on both sides and the fuselage body;

[0026] The two tilt-rotor integrated modules are respectively arranged in the left wing and the right wing.

[0027] In a third aspect, the present invention further provides a method for controlling the drone as provided in the second aspect, the steps of which include:

[0028] During vertical takeoff, the engine unit is started, and the propeller rotates to enter an idle state under the drive of the first output shaft. At the same time, the two second main output shafts respectively drive the corresponding tilt-rotor integrated modules, and the rotors of the main rotor unit in the tilt-rotor integrated module rotate to generate lift to complete vertical takeoff;

[0029] When starting forward flight and the tilt rotor unit is needed, the clutch is first controlled to achieve driving connection between the first secondary output shaft and the worm gear, and the secondary gearbox drives the main rotor unit and the tilt unit to move at the same time, and the rotor of the main rotor unit continues to rotate to generate lift through the universal joint connected to the second secondary output shaft to transmit the driving force;

[0030] The driven gear of the second reversing gearbox rotates forward under the drive of the first secondary output shaft, the worm drives the turbine to rotate forward, the turbine rotates forward around the center of the universal joint by a preset angle, and at the same time drives the rotor arranged on the turbine to rotate forward by the preset angle to realize the tilting flight of the rotor; after the tilting is completed, the UAV transitions from the vertical take-off mode to the fixed-wing level flight mode;

[0031] When the UAV is preparing to land, the driven gear of the first reversing gear box is first controlled to reverse and the propeller is decelerated; at the same time, the driven gear of the second reversing gear box is controlled to reverse, and the worm drives the turbine to rotate in the opposite direction, and the turbine rotates in the opposite direction around the center of the universal joint by a preset angle, and at the same time drives the rotor arranged on the turbine to rotate in the opposite direction by the preset angle to realize the return of the rotor, and the main rotor unit continues to rotate to generate lift to maintain the weight balance of the UAV, and then the clutch is controlled to release the driving connection between the first secondary output shaft and the worm to complete the vertical landing.

[0032] As a further improvement of the above solution, when it is necessary to switch from the level flight state to the hovering state, the driven gear in the first reversing gear box is switched to rotate in the reverse direction, driving the propeller to rotate in the reverse direction to achieve deceleration.

[0033] As a further improvement of the above scheme, the preset angle is 90°; the nose of the drone is assumed to be the origin of the body coordinate system, the X-axis direction of the fuselage is the front-rear direction of the fuselage and the forward direction is positive, the Y-axis direction is the right wing direction and the right direction is positive, and the Z-axis direction is downward and the downward direction is positive;

[0034] When not tilted, the rotor's central axis is parallel to the Z-axis of the fuselage, and the drone takes off and lands vertically.

[0035] When the tilt unit drives the turbine to tilt 90°, the central axis of rotation of the rotor is parallel to the X-axis direction of the fuselage, and the UAV flies forward.

[0036] Since the present invention adopts the above technical solution, the beneficial effects of this application are:

[0037] The present invention provides a single power transmission system, which can directly drive the propeller and the tilt-rotor integrated modules on both sides at the same time by only setting one engine unit through the conversion of the main gear box. Such a setting highly concentrates the power, so that the transmission system provided by the present invention has a compact structure and is convenient for layout on the fuselage of the UAV; at the same time, in the tilt-rotor integrated module, the power can directly drive the main rotor unit and the tilt unit of both wings at the same time through the conversion of the auxiliary gear box to achieve tilting, which solves the problem of low aerodynamic efficiency caused by the non-tilting of the vertical take-off rotor (that is, the use of the tilt-rotor integrated module provided by the present invention can achieve the function of rotor tilting during vertical take-off and ascent), and further concentrates the power. When the corresponding actuator fails and cannot complete the transition flight during vertical take-off or level flight, the power can be switched to another set of actuators, thereby achieving safe landing and reducing the loss of the UAV;

[0038] Specifically, the present invention adopts a combination of a single engine unit, a transmission shaft system, and a turbine worm gear to provide a conventional overall power system for level flight, vertical take-off and landing, and tilting of the UAV. One power output of the engine unit drives the propeller to rotate through a transmission shaft and a reducer to realize forward flight, and the other two power outputs drive the left and right rotor systems through a transmission shaft, a gear box, a clutch, and a turbine worm gear device to realize the tilting conversion between vertical take-off and landing and level flight. Compared with the UAV with a distributed power system, the present invention has a single power, a precise and stable tilting structure, high reliability, a compact system structure, and is easy to maintain. Compared with the UAV with aerodynamic layout in which the front and rear propellers of the fuselage tilt and the rotor inside the wing take-off and landing vertically, the present invention ensures the integrity of the aerodynamic shape of the wing, improves the aerodynamic efficiency of the whole machine, prolongs the flight time of the UAV, and also improves the structural efficiency of the whole UAV. Compared with the UAV that directly adopts a turbine worm gear and a reducer to directly drive multiple sets of rotors to tilt, the present invention has two forms of power output, and in an emergency situation where one rotor fails, it can transition to another flight mode to achieve safe landing.

[0039] In addition, in the present invention, the first main output shaft is connected to the propeller drive through the first reversing gearbox; a reversible first reversing gearbox is arranged near the propeller, and when the UAV switches from level flight to hovering, it only needs to switch the first reversing gearbox to reverse the driven gear connected to the propeller drive, thereby reducing the flight time and flight distance of the UAV when switching from level flight to hovering, saving energy;

[0040] Furthermore, in the tilt-rotor integrated module, the rotor and the rotor drive shaft are tilted by relying on the combined use of the universal joint and the worm gear, which simplifies the tilt structure system. The tilt structure using the worm gear also has a self-locking function, which can effectively ensure the stable angle output during the tilting process. The structural scheme is simple and compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0042] Figure 1 This is a schematic diagram of the internal transmission principle of a drone disclosed in the present invention;

[0043] Figure 2 This is a partial three-dimensional schematic diagram of the tilt-rotor integrated module disclosed in the present invention:

[0044] Figure 3It is a partial cross-sectional schematic diagram of the tilt-rotor integrated module disclosed in the present invention;

[0045] Figure 4 The schematic diagram of the structure principle of the first reversing gearbox and the second reversing gearbox disclosed in the present invention is shown in FIG. Figure 4 a in the figure is a schematic diagram before commutation. Figure 4 b in the figure is the schematic diagram after commutation;

[0046] Figure 5 The schematic diagram of the principle of the tilt-rotor integrated module disclosed in the present invention is shown in FIG. Figure 5 a in the figure is the structural principle diagram before tilting. Figure 5 Figure b is a schematic diagram of the structure tilted 90°.

[0047] Reference numerals:

[0048] 1. Engine unit; 2. Main gearbox; 21. First main output shaft; 22. Second main output shaft;

[0049] 3. Propeller; 4. First reversing gear box; 41. Driving gear; 42. Driven gear; 43. First idler gear; 44. Second idler gear; 45. First connecting rod; 46. Second connecting rod;

[0050] 5. Reduction gearbox; 6. Tilt-rotor integrated module; 61. Sub-gearbox; 611. First sub-output shaft; 612. Second sub-output shaft; 62. Tilt unit; 621. Worm; 622. Turbine; 623. Clutch; 624. Second reversing gearbox; 63. Main rotor unit; 631. First rotor shaft; 632. First bevel gear; 633. Second rotor shaft; 634. Second bevel gear; 635. Rotor; 64. Universal joint;

[0051] 0. Fuselage; 01. Fuselage body; 02. Tail; 03. Left wing; 04. Right wing.

[0052] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0055] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0056] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Example 1

[0057] See also Figure 1-5 , the present invention provides a tiltrotor 635 integrated transmission system, comprising an engine unit 1, a main gearbox 2 drivingly connected to the engine unit 1, and a propeller 3;

[0058] The main gearbox 2 includes a first main output shaft 21 and two second main output shafts 22 symmetrically arranged on both sides of the first main output shaft 21.

[0059] The first main output shaft 21 is drivingly connected to the propeller 3 through the first reversing gear box 4 to drive the propeller 3 to rotate and realize forward flight;

[0060] The two second main output shafts 22 are respectively connected to the tilt-rotor integrated module 6 through the corresponding reduction gearbox 5 to realize the vertical rotation of the rotor 635 to provide lift and to realize the tilt of the rotor 635 so that the rotor 635 of the drone can rotate while tilting;

[0061] The present invention only sets one engine unit 1, which can directly drive the propeller 3 and the tilt-rotor integrated modules 6 on both sides at the same time through the conversion of the main gear box 2. Such a setting highly concentrates the power, making the transmission system provided by the present invention compact and convenient for layout on the fuselage 0 of the UAV; at the same time, in the tilt-rotor integrated module 6, the power can directly drive the main rotor unit 63 and the tilt unit 62 of both wings at the same time through the conversion of the auxiliary gear box 61 to achieve tilting, which solves the problem of low aerodynamic efficiency caused by the non-tilting of the vertical take-off rotor 635 (that is, the tilt-rotor integrated module 6 provided by the present invention can realize the function of tilting the rotor 635 during vertical take-off and ascent), and further concentrates the power. When the corresponding actuator fails and cannot complete the transition flight during vertical take-off or level flight, the power can be switched to another set of actuators, thereby achieving safe landing and reducing the loss of the UAV;

[0062] The first main output shaft 21 is connected to the propeller 3 through the first reversing gear box 4. A reversible first reversing gear box 4 is arranged near the propeller 3. When the UAV switches from level flight to hovering, it only needs to switch the first reversing gear box 4 to achieve reverse rotation of the driven gear 42 connected to the propeller drive, thereby reducing the flight time and flight distance of the UAV when switching from level flight to hovering, saving energy.

[0063] As a preferred embodiment, see Figure 2 and Figure 3 The tilt-rotor integrated module 6 includes a sub-gearbox 61 drivingly connected to the reduction gearbox 5, a tilt unit 62 drivingly connected to the sub-gearbox 61, and a main rotor unit 63;

[0064] The main rotor unit 63 includes a main rotor gearbox and a rotor 635 connected to the output shaft of the main rotor gearbox; the auxiliary gearbox 61 is drivingly connected to the main rotor gearbox through a universal joint 64;

[0065] The tilting unit 62 includes a worm 621 and a turbine 622 meshing with the worm 621, the auxiliary gear box 61 is drivingly connected to the worm 621 via a clutch 623, and a second reversing gear box 624 is further provided between the auxiliary gear box 61 and the clutch 623;

[0066] The main rotor gearbox is arranged on the turbine 622, and the rotating shaft of the turbine 622 is coaxially arranged with a rotating shaft on one side of the universal joint 64, so that the worm 621 drives the turbine 622 to rotate around the center of the universal joint 64 to achieve the preset tilt angle of the rotor 635;

[0067] Specifically, the auxiliary gearbox 61 includes a first auxiliary output shaft 611 and a second auxiliary output shaft 612 , and the first auxiliary output shaft 611 is drivingly connected to the worm 621 through the clutch 623 ;

[0068] The second secondary output shaft 612 is drivingly connected to the main rotor gearbox through the universal joint 64;

[0069] The main rotor gearbox includes a first rotor shaft 631, a first bevel gear 632 arranged on the first rotor shaft 631, a second rotor shaft 633, and a second bevel gear 634 arranged on the second rotor shaft 633, the first rotor shaft 631 and the second rotor shaft 633 are arranged perpendicular to each other, and the first bevel gear 632 and the second bevel gear 634 are meshed and connected;

[0070] The turbine 622 is rotatably disposed on the first rotor shaft 631, and the end of the first rotor shaft 631 away from the first bevel gear 632 is connected to the universal joint 64;

[0071] The end of the second rotor shaft 633 away from the second bevel gear 634 passes through the turbine 622 and is connected to the rotor 635;

[0072] The present invention adopts a combination of a single engine unit 1, a transmission shaft system, a turbine 622, and a worm 621 to provide a conventional overall power system for level flight, vertical take-off and landing, and tilting of the UAV. One power output of the engine unit 1 drives the propeller 3 to rotate through the transmission shaft and the reducer to realize forward flight, and the other two power outputs drive the left and right main rotor units through the transmission shaft and the gear box, the clutch 623, the turbine 622, and the worm 621 device to realize the tilting conversion between vertical take-off and landing and level flight. Compared with the UAV with distributed power system, the present invention has a single power, a precise and stable tilting structure, high reliability, The system structure is compact and easy to maintain; compared with the aerodynamic layout UAV with tilting propellers in front and behind the fuselage 0 and vertical take-off and landing of the rotor 635 inside the wing, the present invention ensures the integrity of the aerodynamic shape of the wing, improves the aerodynamic efficiency of the whole machine, prolongs the flight time of the UAV, and also improves the structural efficiency of the whole UAV; compared with the UAV that directly uses the turbine 622, worm 621 and reducer to directly drive multiple sets of rotors 635 to tilt, the present invention has two forms of power output, and in the emergency situation of a failure of one rotor 635, it can transition to another flight mode to achieve safe landing;

[0073] Furthermore, in the tilt-rotor integrated module 6, the rotor 635 and the rotor drive shaft are tilted by relying on the combined use of the universal joint 64 and the turbine 622 and worm 621, which simplifies the tilt structure system. The tilt structure using the turbine 622 and worm 621 also has a self-locking function, which can effectively ensure the stable angle output during the tilting process, and the structural scheme is simple and compact.

[0074] As a preferred embodiment, see Figure 4 The first reversing gear box 4 and the second reversing gear box 624 have the same structure; they respectively include a driving gear 41, a driven gear 42, a first idler gear 43 and a second idler gear 44; a first connecting rod 45 is provided between the first idler gear 43 and the second idler gear 44, and a second connecting rod 46 is provided between the driven gear 42 and the second idler gear 44;

[0075] The first reversing gear box 4 and the second reversing gear box 624 further include connecting rod driving mechanisms, respectively, for driving the second connecting rod 46 and the first connecting rod 45 to swing so as to swing the first idler gear 43 and / or the second idler gear 44 between the driving gear 41 and the driven gear 42;

[0076] In the first state, see Figure 4 In a, the connecting rod driving mechanism swings the first idler wheel 43 and the second idler wheel 44 between the driving gear 41 and the driven gear 42, and the driving gear 41 is meshed with the driven gear 42 through the first idler wheel 43 and the second idler wheel 44 in turn for positive transmission;

[0077] In the second state, see Figure 4 b, the connecting rod driving mechanism only swings the second idler gear 44 between the driving gear 41 and the driven gear 42, and the driving gear 41 is meshed with the driven gear 42 through the second idler gear 44 for reverse transmission;

[0078] Specifically, in the first reversing gearbox 4, the driving gear 41 is connected to the first main output shaft 21 of the main gearbox 2 through a coupling, and the output shaft of the driven gear 42 is connected to the propeller. In the first state, the first reversing gearbox 4 drives the propeller to rotate forward, and in the second state, the first reversing gearbox 4 drives the propeller to rotate reversely. The setting of the first reversing gearbox 4 can reduce the flight time and flight distance of the drone when switching from level flight to hovering, saving energy.

[0079] In the second reversing gearbox 624, the driving gear 41 is connected to the first secondary output shaft 611 of the secondary gearbox 61 through a coupling, and the output shaft of the driven gear 42 is connected to the clutch 623. In the first state, the second reversing gearbox 624 drives the clutch 623 to rotate forward, and the clutch 623 drives the screw to rotate forward, thereby driving the turbine 622 to rotate forward by a preset tilt angle; in the second state, the second reversing gearbox 624 drives the clutch 623 to rotate reversely, and the clutch 623 drives the screw to rotate reversely, thereby driving the turbine 622 to rotate reversely by a preset tilt angle;

[0080] First, the turbine 622 and worm 621 are used as the tilting power, and their power sources and the power sources of the rotor 635 unit are integrated on the sub-gear box 61. Through the setting of the second reversing gear box 624, the tilting is completed and the UAV enters the level flight stage; when the UAV is ready to land, the second reversing gear box 624 is switched to reverse, so that its driven gear 42 is reversed, so that only the worm 621 is reversed to drive the turbine 622 and the rotor 635 set on the turbine 622 to return to the normal position to generate lift to maintain the power of the UAV to continue vertical landing. Example 2

[0081] The present invention also provides a drone, comprising a fuselage 0 and a tilt-rotor 635 integrated transmission system as provided in Example 1 and arranged in the fuselage 0; the fuselage 0 comprises a fuselage body 01 and a tail 02 arranged at the tail of the fuselage body 01, and a left wing 03 and a right wing 04 symmetrically arranged on both sides of the fuselage body 01;

[0082] The engine unit 1 is arranged at the fuselage body 01 near the center of gravity of the whole machine, the first reversing gearbox 4 is arranged at the fuselage body 01 near the nose, the propeller 3 is arranged at the nose, and the main gearbox 2 is arranged at the intersection of the wings on both sides and the fuselage body 01;

[0083] The two tilt-rotor integrated modules 6 are respectively disposed in the left wing 03 and the right wing 04;

[0084] The drone provided by the present invention uses a set of engine units 1 to simultaneously drive the propeller 3 and the rotor 635 to rotate to generate pulling force and vertical take-off and landing lift, and also provides power for the main rotor unit 63 to tilt, thereby reducing the problem of the tilt mechanism needing to be additionally configured with a power source, and realizing the centralization of the energy system;

[0085] In addition, the propeller at the nose of the fuselage 0 and the tilt-rotor integrated module 6 on both sides of the wing are output by different output shafts. When a set of actuators fails, the transition flight can be executed immediately to ensure the safe landing of the UAV.

[0086] The rotors 635 arranged on both sides of the wings can also be tilted, thereby improving the aerodynamic efficiency of the UAV during level flight, extending the flight time and range; combined with the variable pitch mechanism arranged under the rotors 635, the flight attitude adjustment control function of the UAV during take-off and landing can be completed. Example 3

[0087] The present invention also provides a method for controlling the drone as provided in Example 2, the steps of which include:

[0088] During vertical takeoff, the engine unit 1 is started, and the propeller 3 rotates to enter an idle state under the drive of the first output shaft. At the same time, the two second main output shafts 22 respectively drive the corresponding tilt-rotor integrated module 6, and the rotor 635 of the main rotor unit 63 in the tilt-rotor integrated module 6 rotates to generate lift to complete vertical takeoff;

[0089] When starting forward flight and the main rotor unit 63 needs to be tilted, the clutch 623 is first controlled to operate to achieve driving connection between the first secondary output shaft 611 and the worm 621, and the secondary gear box 61 drives the main rotor unit 63 and the tilt unit 62 to operate at the same time, and the rotor 635 of the main rotor unit 63 continues to rotate to generate lift through the universal joint 64 connected to the second secondary output shaft 612 to transmit the driving force;

[0090] The driven gear 42 of the second reversing gear box 624 rotates forward under the drive of the first secondary output shaft 611, and the worm 621 drives the turbine 622 to rotate forward, and the turbine 622 rotates forward around the center of the universal joint 64 by a preset angle, and at the same time drives the rotor 635 provided on the turbine 622 to rotate forward by the preset angle to realize the tilting flight of the rotor 635. After the tilting is completed, the UAV transitions from the vertical take-off mode to the fixed-wing level flight mode;

[0091] When the UAV is ready to land, the driven gear 42 of the first reversing gearbox 4 is first controlled to reverse, and the propeller 3 is decelerated; at the same time, the driven gear 42 of the second reversing gearbox 624 is controlled to reverse, and the worm 621 drives the turbine 622 to rotate in the opposite direction, and the turbine 622 rotates in the opposite direction around the center of the universal joint 64 by a preset angle, and at the same time drives the rotor 635 arranged on the turbine 622 to rotate in the opposite direction by the preset angle to realize the return of the rotor 635, and the main rotor unit 63 continues to rotate to generate lift to maintain the weight balance of the UAV, and then the clutch 623 is controlled to act to release the driving connection between the first secondary output shaft 611 and the worm 621, and the vertical landing is completed;

[0092] With such a configuration, the rotors 635 arranged on the wings on both sides can both rotate and tilt, thereby improving the aerodynamic efficiency of the UAV during level flight and increasing the flight time of the UAV. In addition, the tilting of the present invention relies on the combined action of the universal joint 64 and the turbine 622 and worm 621 to tilt the rotor 635 and the rotor drive shaft, thereby simplifying the tilting structure system. The tilting structure using the turbine 622 and worm 621 structure also has a self-locking function, which can effectively ensure the stable angle output during the tilting process, and the structural scheme is simple and compact.

[0093] As a preferred embodiment, when it is necessary to switch from a level flight state to a hovering state, the driven gear 42 in the first reversing gear box 4 is switched to rotate in the opposite direction, driving the propeller to rotate in the opposite direction to achieve deceleration; the setting of the first reversing gear box 4 can reduce the flight time and flight distance of the UAV when switching from level flight to hovering, thereby saving energy.

[0094] As a preferred embodiment, see Figure 5 , the preset angle is 90°; assuming that the drone nose is the origin of the body coordinate system, the X-axis direction of the fuselage 0 is the front-rear direction of the fuselage 0 and the forward direction is positive, the Y-axis direction is the direction of the right wing 04 and the right direction is positive, and the Z-axis direction is downward and the downward direction is positive;

[0095] In the non-tilted condition, see Figure 5 In a, the rotation center axis of the rotor 635 is parallel to the Z-axis direction of the fuselage 0, and the UAV takes off and lands vertically;

[0096] When the tilting unit 62 drives the turbine 622 to tilt 90°, see Figure 5 In b, the rotation center axis of the rotor 635 is parallel to the X-axis direction of the fuselage 0, and the UAV flies forward.

[0097] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A single power transmission system, characterized in that: comprising an engine unit, a main gearbox drivingly connected to the engine unit, and a propeller; The main gearbox comprises a first main output shaft and two second main output shafts symmetrically arranged on both sides of the first main output shaft. The first main output shaft is drivingly connected to the propeller through a first reversing gear box; The two second main output shafts are respectively driven and connected to the tilt-rotor integrated module through corresponding reduction gear boxes; The tilt-rotor integrated module comprises a sub-gearbox drivingly connected to the reduction gearbox, a tilt unit drivingly connected to the sub-gearbox, and a main rotor unit; The main rotor unit comprises a main rotor gearbox and a rotor connected to an output shaft of the main rotor gearbox; the auxiliary gearbox is drivingly connected to the main rotor gearbox via a universal joint; The tilting unit includes a worm and a turbine meshing with the worm, the auxiliary gear box is drivingly connected to the worm through a clutch, and a second reversing gear box is further provided between the auxiliary gear box and the clutch; The auxiliary gearbox comprises a first auxiliary output shaft and a second auxiliary output shaft, wherein the first auxiliary output shaft is drivingly connected to the worm through the clutch; The second secondary output shaft is drivingly connected to the main rotor gearbox via the universal joint; The main rotor gearbox is arranged on the turbine, and the rotating shaft of the turbine is coaxially arranged with a rotating shaft on one side of the universal joint, so that the worm drives the turbine to rotate around the center of the universal joint to realize the preset tilt angle of the rotor.

2. A single power transmission system according to claim 1, characterized in that: The main rotor gearbox comprises a first rotor shaft, a first bevel gear arranged on the first rotor shaft, a second rotor shaft, and a second bevel gear arranged on the second rotor shaft, the first rotor shaft and the second rotor shaft are arranged perpendicular to each other, and the first bevel gear and the second bevel gear are meshed and connected; The turbine is rotatably arranged on the first rotor shaft, and the end of the first rotor shaft away from the first bevel gear is connected to the universal joint; The end of the second rotor shaft away from the second bevel gear passes through the turbine and is connected to the rotor.

3. A single power transmission system according to claim 1 or 2, characterized in that: The first reversing gearbox comprises a driving gear, a driven gear, a first idler gear and a second idler gear; a first connecting rod is arranged between the first idler gear and the second idler gear, and a second connecting rod is arranged between the driven gear and the second idler gear; In the first state, the driving gear is meshed and driven with the driven gear through the first idler gear and the second idler gear in sequence; In the second state, the driving gear is meshed and transmitted with the driven gear through the second idler gear.

4. A single power transmission system according to claim 3, characterized in that: The first reversing gear box further comprises a connecting rod driving mechanism for driving the second connecting rod and the first connecting rod to swing so as to swing the first idler gear and / or the second idler gear between the driving gear and the driven gear.

5. A drone, characterized in that: A single power transmission system according to any one of claims 1 to 4, comprising a fuselage and arranged in the fuselage; the fuselage comprises a fuselage body and a tail arranged at the tail of the fuselage body, and a left wing and a right wing symmetrically arranged on both sides of the fuselage body; The engine unit is arranged at the fuselage body close to the center of gravity of the whole machine, the first reversing gearbox is arranged at the fuselage body close to the nose, the propeller is arranged at the nose, and the main gearbox is arranged at the intersection of the wings on both sides and the fuselage body; The two tilt-rotor integrated modules are respectively arranged in the left wing and the right wing.

6. A method for controlling a drone as claimed in claim 5, characterized in that: The steps include: During vertical takeoff, the engine unit is started, and the propeller rotates to enter an idle state under the drive of the first output shaft. At the same time, the two second main output shafts respectively drive the corresponding tilt-rotor integrated modules, and the rotors of the main rotor unit in the tilt-rotor integrated module rotate to generate lift to complete vertical takeoff; When starting forward flight and the main rotor unit needs to be tilted, the clutch is first controlled to achieve driving connection between the first secondary output shaft and the worm gear, and the secondary gearbox drives the main rotor unit and the tilt unit to move at the same time, and the rotor of the main rotor unit continues to rotate to generate lift through the universal joint connected to the second secondary output shaft to transmit the driving force; The driven gear of the second reversing gearbox rotates forward under the drive of the first secondary output shaft, and the worm drives the turbine to rotate forward, and the turbine rotates forward around the center of the universal joint by a preset angle, and at the same time drives the rotor arranged on the turbine to rotate forward by the preset angle to realize the tilting flight of the rotor. After the tilting is completed, the UAV transitions from the vertical take-off mode to the fixed-wing level flight mode; When the UAV is preparing to land, the driven gear of the first reversing gear box is first controlled to reverse and the propeller is decelerated; at the same time, the driven gear of the second reversing gear box is controlled to reverse, and the worm drives the turbine to rotate in the opposite direction, and the turbine rotates in the opposite direction around the center of the universal joint by a preset angle, and at the same time drives the rotor arranged on the turbine to rotate in the opposite direction by the preset angle to realize the return of the rotor, and the main rotor unit continues to rotate to generate lift to maintain the weight balance of the UAV, and then the clutch is controlled to release the driving connection between the first secondary output shaft and the worm to complete the vertical landing.

7. The control method according to claim 6, characterized in that: When it is necessary to switch from the level flight state to the hovering state, the driven gear in the first reversing gear box is switched to rotate in the reverse direction, thereby driving the propeller to rotate in the reverse direction to achieve deceleration.

8. The control method according to claim 6 or 7, characterized in that: The preset angle is 90°; the nose of the drone is the origin of the body coordinate system, the X-axis direction of the fuselage is the front-to-back direction of the fuselage and the forward direction is positive, the Y-axis direction is the right wing direction and the right direction is positive, and the Z-axis direction is downward and the downward direction is positive; When not tilted, the rotor's central axis is parallel to the Z-axis of the fuselage, and the drone takes off and lands vertically; When the tilt unit drives the turbine to tilt 90°, the central axis of rotation of the rotor is parallel to the X-axis direction of the fuselage, and the UAV flies forward.

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