Transmission mechanism of tandem double-rotor helicopter

Abstract

The utility model is suitable for the technical field of unmanned helicopters, and provides a tandem double-rotor helicopter transmission mechanism which comprises a driving assembly and a gearbox assembly. The driving assembly comprises a holder fixedly installed on the machine body, a driving wheel shaft and a driven wheel shaft are rotatably arranged on the holder, the driving wheel shaft and the driven wheel shaft are fixedly sleeved with a driving wheel and a driven wheel respectively, and the front end and the rear end of the driven wheel shaft are connected with transmission shafts through couplings respectively. The transmission mechanism of the tandem type double-rotor helicopter overcomes the defects that a conventional transmission mechanism of the tandem type double-rotor helicopter is complex in mechanical structure, large in number of parts, heavy in weight, poor in stability, high in fuselage vibration level and the like, the transmission mechanism of the tandem type double-rotor helicopter is simplified, the number of the transmission mechanism and the number of the parts are reduced, and the reliability of the tandem type double-rotor helicopter is improved. The unmanned aerial vehicle is more compact in structure, the environmental applicability of the unmanned aerial vehicle is improved, and the overall reliability and stability of the system are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of unmanned helicopters, and particularly relates to a transmission mechanism of a tandem double-rotor helicopter. Background Technique

[0002] At present, common transport helicopters mainly include single-rotor helicopters with tail rotors, tandem double-rotor helicopters, transverse double-rotor helicopters, and coaxial double-rotor helicopters. Tandem double-rotor helicopters are widely used in tactical transportation, passenger transportation, medical treatment, search and rescue and other tasks because of their more compact structure, small space size, large load capacity, allowing a large change in the center of gravity, strong anti-side wind disturbance ability, being conducive to shipboard use, and having a high hovering efficiency.

[0003] However, the existing transmission mechanism of tandem double-rotor helicopters has a relatively complex mechanical structure, large weight, complex structure, and poor stability; the front transmission system and the rear transmission system are mechanically rigidly connected, and the vibrations of the front rotor system and the rear rotor system interfere with each other, resulting in a high level of fuselage vibration, and there are some deficiencies in use. Content of the Utility Model

[0004] The utility model provides a transmission mechanism of a tandem double-rotor helicopter, aiming to solve the problems of relatively complex mechanical structure, large weight, complex structure, and poor stability of the existing transmission mechanism of tandem double-rotor helicopters; the front transmission system and the rear transmission system are mechanically rigidly connected, and the vibrations of the front rotor system and the rear rotor system interfere with each other, resulting in a high level of fuselage vibration.

[0005] The utility model is realized as follows: A transmission mechanism of a tandem double-rotor helicopter includes a drive assembly located in the middle and gearbox assemblies located at the front and rear ends;

[0006] The drive assembly includes a cage fixedly installed on the fuselage. A driving wheel shaft and a driven wheel shaft are rotatably arranged on the cage. A driving wheel and a driven wheel are respectively fixedly sleeved on the driving wheel shaft and the driven wheel shaft. The driven wheel is connected to the driving wheel through a synchronous belt transmission, and a pressing wheel is arranged on the cage for pressing the synchronous belt adjustably; the front and rear ends of the driven wheel shaft are respectively connected to a transmission shaft through couplings;

[0007] The gearbox assembly includes a fixing frame fixedly installed on the fuselage. A transmission gearbox is arranged on the fixing frame. The input shaft of the transmission gearbox is fixedly connected to a transmission shaft. The output shaft of the transmission gearbox faces upward and is fixedly connected to a driving shaft. The rotation directions of the driving shafts of the two gearbox assemblies are opposite.

[0008] Preferably, a mounting frame is fixedly installed on the fixing frame, and a servo mechanism is arranged on the mounting frame.

[0009] Preferably, the servo assembly includes a drive motor, an eccentric wheel and a servo pull rod. The drive motor is fixedly installed on the mounting bracket. The eccentric wheel is eccentrically and fixedly installed on the output shaft of the drive motor. The bottom end of the servo pull rod is rotatably arranged on the protruding part of the surface of the eccentric wheel.

[0010] Preferably, it further includes a pinch roller shaft. Both ends of the surface of the pinch roller shaft are movably penetrated with mounting bolts. The mounting bolts are threadedly installed on the cage. A spring for pressing against the pinch roller shaft is sleeved on the surface of the mounting bolts between the cage and the pinch roller shaft. The pinch roller is rotatably sleeved on the pinch roller shaft.

[0011] Beneficial effects

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows: The transmission mechanism of the tandem dual-rotor helicopter of the present utility model solves the disadvantages of the conventional tandem dual-rotor helicopter transmission mechanism, such as complex mechanical structure, large number of parts, heavy weight, complex structure, poor stability, and high fuselage vibration level. It simplifies the transmission mechanism of the tandem dual-rotor helicopter, reduces the number of transmission mechanisms and parts, makes the structure of the unmanned aerial vehicle more compact, improves the environmental adaptability of the unmanned aerial vehicle, and enhances the overall reliability and stability of the system. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of the present utility model;

[0014] Figure 2 is a schematic structural diagram of the gearbox assembly in the present utility model;

[0015] Figure 3 For the present utility model Figure 1 is a partial enlarged view of part A;

[0016] In the figure: 1 - drive assembly, 11 - cage, 12 - driven wheel, 13 - driving wheel, 14 - pinch roller, 15 - pinch roller shaft, 16 - mounting bolt, 17 - spring, 2 - transmission shaft, 3 - gearbox assembly, 31 - fixing bracket, 32 - transmission gearbox, 33 - drive shaft, 34 - mounting bracket, 35 - drive motor, 36 - eccentric wheel, 37 - servo pull rod. Detailed Embodiment

[0017] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0018] Please refer toFigures 1-3 , the utility model provides a technical solution: a longitudinal tandem rotor helicopter transmission mechanism, which includes a drive assembly 1 located in the middle and gearbox assemblies 3 located at the front and rear ends;

[0019] The drive assembly 1 includes a cage 11 fixedly installed on the fuselage. A driving wheel shaft and a driven wheel shaft are rotatably arranged on the cage 11. A driving wheel 13 and a driven wheel 12 are respectively fixedly sleeved on the driving wheel shaft and the driven wheel shaft. The driven wheel 12 is connected to the driving wheel 13 through a synchronous belt drive, and a pressing wheel 14 is adjustably arranged on the cage 11 for pressing the synchronous belt; both ends of the driven wheel shaft are respectively connected to a transmission shaft 2 through a coupling.

[0020] On the one hand, the cage can maintain the spatial positions of the driving wheel 13 and the driven wheel 12, and on the other hand, it can fix the synchronous belt and the belt wheels on the fuselage frame, reduce the vibration level of the fuselage, and improve the stability and reliability of the transmission system.

[0021] One end of the driving wheel shaft is fixedly connected to the output shaft of the engine through a coupling, and the power provided by the engine is transmitted to the driving wheel 13 through a flat key to drive the driving wheel 13 to rotate, so as to drive the driven wheel 12 to rotate through the synchronous belt, and the driven wheel shaft of the driven wheel 12 drives the two transmission shafts 2 to rotate.

[0022] The driven wheel 12 can also be rotatably connected to the driven wheel shaft, and a one-way clutch is arranged between the two, which can make the structural member rotate in a predetermined direction and lock in the other direction to prevent the inner ring from reversing, which is beneficial to reducing the structural complexity and cost.

[0023] It also includes a pressing wheel shaft 15. Both ends of the surface of the pressing wheel shaft 15 are movably penetrated with mounting bolts 16. The mounting bolts 16 are threadedly installed on the cage 11. A spring 17 for pressing the pressing wheel shaft 15 is sleeved on the surface of the mounting bolts 16 between the cage 11 and the pressing wheel shaft 15. The pressing wheel 14 is rotatably sleeved on the pressing wheel shaft 15.

[0024] The pressing wheel 14 is essentially a tensioning wheel, which is used to press the synchronous belt to avoid slipping and ensure the stable synchronous rotation of the driving wheel 13 and the driven wheel 12.

[0025] By tightening or loosening the nut, the position of the pressing wheel shaft 15 relative to the synchronous belt is changed, so as to adjust the degree of the pressing wheel 14 pressing the synchronous belt.

[0026] The gearbox assembly 3 includes a fixed bracket 31 fixedly mounted on the fuselage. A transmission gearbox 32 is provided on the fixed bracket 31. The input shaft of the transmission gearbox 32 is fixedly connected to a transmission shaft 2 through a coupling. The output shaft of the transmission gearbox 32 extends upward and is fixedly connected to a drive shaft 33. The rotation directions of the drive shafts 33 of the two gearbox assemblies 3 are opposite.

[0027] In this embodiment, a set of bevel gears are used for transmission inside the transmission gearbox 32, including a vertically arranged first bevel gear and a horizontally arranged second bevel gear, which mesh with each other. The first bevel gear is mounted on the input shaft, the second bevel gear is mounted on the output shaft, and the drive shaft 33 is mounted on the output shaft, so as to drive the drive shaft 33 to rotate.

[0028] The two transmission gearboxes 32 are located at both ends respectively. Therefore, the first bevel gears of the two transmission gearboxes 32 are arranged back to back, so as to realize the same-speed and reverse rotation of the two drive shafts 33, thereby driving the two groups of blades to rotate in the opposite direction and realizing the power transmission of the tandem rotor helicopter.

[0029] Furthermore, a mounting bracket 34 is fixedly mounted on the fixed bracket 31, and a servo assembly is provided on the mounting bracket 34.

[0030] In this embodiment, a mounting position for installing the blade swashplate is provided at the top of the drive shaft 33, and the blades are mounted on the blade swashplate. Thus, the inclination angle of each group of blades can be controlled by pulling the blade swashplate through the servo assembly. Deep groove ball bearings are arranged inside the blade swashplate to ensure the normal operation of the swashplate.

[0031] Furthermore, the servo assembly includes a drive motor 35, an eccentric wheel 36 and a servo pull rod 37. The drive motor 35 is fixedly mounted on the mounting bracket 34. The eccentric wheel 36 is eccentrically fixedly mounted on the output shaft of the drive motor 35. The bottom end of the servo pull rod 37 is rotatably arranged on the protruding part of the surface of the eccentric wheel 36.

[0032] The drive motor 35 is an SF110KG type linear motor.

[0033] In this embodiment, there are multiple groups of servo assemblies. The top ends of the servo pull rods 37 are hinged to the blade swashplate. When the eccentric wheel 36 rotates, it will drive the bottom end of the servo pull rod 37 to move, thereby changing the height of the bottom end of the servo pull rod 37, and thus pulling the servo pull rod 37 downward, so as to pull down this side of the blade swashplate. At this time, the protruding part of the eccentric wheel 36 on the opposite side should swing upward, so as to give space for the corresponding servo pull rod 37 to move upward, so that the opposite side of the blade swashplate can move upward.

[0034] The front and rear rotor systems each contain two blades, and the blade angle is 180°. To make the structure of the drone more compact, it is necessary to minimize the axial distance between the front and rear rotor systems as much as possible. For this purpose, by adjusting the bevel gear assembly in the gearbox, when working normally, the straight lines formed by the blades of the two systems are always perpendicular, shortening the axial distance between the two rotor shafts and increasing the blade disk overlap rate to 30.4%. This makes the structure of the drone more compact and improves the environmental adaptability of the drone.

[0035] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A transmission mechanism for a tandem twin-rotor helicopter, characterized in that: It comprises a driving assembly (1) located in the middle and a gear box assembly (3) located at the front and rear ends; The driving assembly (1) comprises a holder (11) fixedly mounted on the machine body, a driving wheel shaft and a driven wheel shaft rotatably provided on the holder (11), a driving wheel (13) and a driven wheel (12) being fixedly sleeved on the driving wheel shaft and the driven wheel shaft respectively, the driven wheel (12) being connected to the driving wheel (13) via a synchronous belt transmission, and a belt pressing wheel (14) which is adjustable and used for pressing the synchronous belt is provided on the holder (11); the front and rear ends of the driven wheel shaft are respectively connected to the transmission shaft (2) via couplings; The gearbox assembly (3) comprises a fixing frame (31) fixedly mounted on a fuselage, a transmission gearbox (32) is arranged on the fixing frame (31), an input shaft of the transmission gearbox (32) is fixedly connected to a transmission shaft (2), an output shaft of the transmission gearbox (32) is upwardly and fixedly connected to a drive shaft (33), and the rotation directions of the drive shafts (33) of the two gearbox assemblies (3) are opposite.

2. A tandem twin-rotor helicopter transmission mechanism as claimed in claim 1, characterized in that: A mounting frame (34) is fixedly mounted on the fixing frame (31), and a steering gear assembly is arranged on the mounting frame (34).

3. A tandem twin-rotor helicopter transmission mechanism as claimed in claim 2, characterized in that: The steering gear assembly comprises a driving motor (35), an eccentric wheel (36) and a steering gear pull rod (37); the driving motor (35) is fixedly mounted on the mounting frame (34); the eccentric wheel (36) is eccentrically fixedly mounted on the output shaft of the driving motor (35); and the bottom end of the steering gear pull rod (37) is rotatably arranged on a protruding portion of the surface of the eccentric wheel (36).

4. The transmission mechanism of a tandem twin-rotor helicopter according to claim 1, characterized in that: It also includes a belt-pressing roller shaft (15), both ends of the surface of which are movably provided with mounting bolts (16), the mounting bolts (16) being installed on the retaining frame (11) by means of threads, a spring (17) being sleeved on the surface of the mounting bolts (16) and used for tightening the belt-pressing roller shaft (15) is provided between the retaining frame (11) and the belt-pressing roller shaft (15), and the belt-pressing roller (14) is rotatably sleeved on the belt-pressing roller shaft (15).

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