Periodic pitch control mechanism for unmanned helicopter

Abstract

The utility model discloses a kind of unmanned helicopter periodic variable pitch control mechanism, belong to unmanned aerial vehicle technical field, including direction adjusting mechanism and special-shaped variable direction adjusting disc, direction adjusting mechanism has pivot, wing plate and rotor paddle clamp, special-shaped variable direction adjusting disc is sleeved in the outer periphery of pivot, mechanism further include rudder mechanism, rudder mechanism includes the rudder support of fixed connection in mechanism non-rotating part, micro servo rudder on rudder support, spherical bent pull rod and spherical nut, one end of spherical bent pull rod is rotatably connected with the output end of micro servo rudder, the other end is rotatably connected with spherical nut, spherical nut is then fixedly connected to the lower surface of special-shaped variable direction adjusting disc.The utility model directly drives adjusting disc by setting compact rudder mechanism, solve the problem of long transmission chain in prior art, complex structure, slow response, with the beneficial effects of simplified structure, accurate adjustment, transmission flexible.

Description

Technical Field

[0001] This utility model relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a periodic pitch control mechanism for unmanned helicopters. Background Technology

[0002] Unmanned helicopters are increasingly used in aerial photography, reconnaissance, and logistics due to their ability to take off and land vertically, hover, and maneuver. Flight control is one of the core technologies of unmanned helicopters, and cyclic pitch control is the key to achieving forward, backward, and lateral flight.

[0003] Cyclic pitch control is typically achieved by using an onboard servo motor to tilt the swashplate. The servo motor receives commands from the flight control system and outputs precise displacements. These displacements are transmitted to the swashplate via a series of mechanical linkages, causing the swashplate to tilt at a specific angle. As the tilted swashplate rotates with the main shaft, it periodically changes the rotor blade pitch via a linkage, generating uneven lift in the rotor's plane of rotation, thus propelling the helicopter in the designated direction.

[0004] In existing technologies, the transmission structure from the servo motor to the swashplate is designed to be quite complex. To accommodate layout and lever arm ratio requirements, multiple push-pull rods, rocker arms, or crank-connecting rods are used in combination to transmit control actions. This complex mechanical transmission chain not only increases the number of parts, resulting in a larger overall size and weight, but is also a significant drawback for unmanned helicopters, which are extremely sensitive to space and load constraints.

[0005] Excessively long drive chains and numerous connecting hinge points can lead to the accumulation of mechanical backlash. This accumulated backlash manifests as control lag and inconsistency during frequent forward and reverse movements of the servo motor, reducing the response speed and steering accuracy of the control system. This structure is also more cumbersome to install and debug, and its accuracy decreases due to wear after long-term use, increasing the difficulty and cost of maintenance.

[0006] Therefore, this invention proposes a periodic pitch control mechanism for unmanned helicopters to address the shortcomings of existing technologies. Utility Model Content

[0007] In view of the problems in the existing technology of a periodic pitch control mechanism for unmanned helicopters, such as excessively long transmission chains leading to complex structure, large size and weight, and accumulated mechanical backlash causing lag in control response and low adjustment accuracy, this utility model aims to provide a periodic pitch control mechanism for unmanned helicopters with an improved structure that can effectively solve the above problems.

[0008] This utility model provides a periodic pitch control mechanism for an unmanned helicopter, comprising: a directional mechanism having a wingplate, a rotating shaft, and a rotor clip hinged to the root of the wingplate; and a shaped directional adjustment disc sleeved on the outer periphery of the rotating shaft.

[0009] The servo mechanism includes a servo bracket fixedly connected to the non-rotating part of the mechanism, a miniature servo motor mounted on the servo bracket, and a spherical bent tie rod and a spherical nut for transmitting motion.

[0010] Furthermore, in terms of connection, one end of the spherical curved tie rod is rotatably connected to the output end of the micro servo motor, while the other end is rotatably connected to the spherical nut. The spherical nut is ultimately fixedly connected to the lower surface of the irregular-shaped steering adjustment disc, thus forming a compact and direct control transmission chain for driving the irregular-shaped steering adjustment disc to produce lifting or tilting displacement.

[0011] Preferably, the steering mechanism also includes a steering pile and a coupling device. To realize the transmission of control actions, one end of the coupling device is rotatably connected to the steering pile, and the other end is rotatably connected to the rotor clip. The coupling device is used to accurately transmit the movement of the irregular steering adjustment disc to the rotor clip.

[0012] Preferably, the steering mechanism further includes a protective frame and a rotor head guide wheel. The protective frame is fixedly installed on the top of the steering mechanism, and the rotor head guide wheel is installed inside the protective frame. The rotor head guide wheel slides in contact with the wing plate at a designated position. This design is used to effectively limit the movement trajectory of the wing plate and improve rotational stability.

[0013] Preferably, in order to achieve separation of static and dynamic components, the irregular-shaped reversing adjustment disc includes a non-rotating part connected to a ball nut and a rotating part connected to a coupling. The rotating part and the non-rotating part rotate relative to each other through bearings to ensure stable control input, while the actuator rotates with the main shaft.

[0014] Preferably, the spherical curved tie rod is a rigid rod with a preset curvature. The specific curvature allows it to avoid other components during movement and ensures the flexibility of the adjustment process, thus avoiding mechanical interference.

[0015] Preferably, the ball joint connection is formed between the ball nut and the ball-shaped bent tie rod. This universal joint connection allows the ball-shaped bent tie rod to swing freely relative to the irregularly shaped directional adjustment disc in multiple degrees of freedom, so as to adapt to complex spatial control angles.

[0016] Preferably, the servo mechanism also includes a battery as a power source, and a mounting bracket for mounting and securing the battery. The mounting bracket is located adjacent to the servo bracket to facilitate centralized power supply and optimize the center of gravity of the device.

[0017] Preferably, the mechanism also includes a connecting ring and a connecting plate for mounting the entire mechanism to the drone fuselage. The connecting plate is fixed to the base of the mechanism, while the connecting ring provides a quick-connect and disconnect interface for easy maintenance and replacement.

[0018] This utility model has the following beneficial effects: 1. This utility model solves the problems of long transmission chains, complex structures, and response delays in existing periodic pitch control mechanisms by setting up a servo mechanism consisting of a micro servo motor, a spherical bent tie rod, and a spherical nut to directly drive the irregularly shaped directional adjustment disc. This achieves the goal of simplifying the overall structure, shortening the control cycle, and improving the control response speed and accuracy.

[0019] 2. This utility model solves the problem of mechanical interference and adjustment dead angle that may occur in traditional straight rods in complex spatial movements by using a spherical curved tie rod with a preset curvature and forming a ball joint connection between it and the spherical nut. It achieves flexible adjustment action, smooth transmission and omnidirectional control without dead angle.

[0020] 3. This utility model solves the problem of unstable movement and affected aircraft attitude caused by aerodynamic factors during high-speed rotation of the rotor by setting a rotor head guide wheel and a protective frame for mounting the guide wheel, and by using the rotor head guide wheel to slide and restrict the movement trajectory of the wing plate. This achieves the goal of ensuring stable movement of the wing plate within a preset trajectory and improving the flight stability of the UAV. Attached Figure Description

[0021] Figure 1 This is a perspective view of a periodic pitch control mechanism for an unmanned helicopter proposed in this utility model. Figure 2 This is a side view of a cyclic pitch control mechanism for an unmanned helicopter proposed in this utility model. Figure 3 This is a schematic diagram of the steering mechanism of a periodic pitch control mechanism for an unmanned helicopter proposed in this utility model. Figure 4 This is a diagram illustrating the servo mechanism of a cyclic pitch control mechanism for an unmanned helicopter proposed in this utility model.

[0022] Legend: 1. Irregularly shaped steering adjustment disc; 2. Steering mechanism; 201. Protective frame; 202. Steering pile; 203. Coupling unit; 204. Rotor head guide wheel; 205. Wing plate; 206. Rotating shaft; 207. Rotor clip; 3. Servo mechanism; 301. Battery; 302. Miniature servo servo; 303. Servo bracket; 304. Spherical bent tie rod; 305. Spherical nut; 306. Fixing bracket; 307. Connecting ring; 308. Connecting plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example: Please refer to Figures 1 to 4 This utility model provides a periodic pitch control mechanism for unmanned helicopters, which aims to solve the problems of complex structure, long transmission chain, slow response and large size and weight of existing periodic pitch control mechanisms for unmanned helicopters.

[0025] like Figure 1 and Figure 2 As shown, the basic framework of a periodic pitch control mechanism for an unmanned helicopter includes a steering mechanism 2, a shaped steering adjustment disk 1 as a transmission component, and a servo mechanism 3 as a control source. The servo mechanism 3 drives the shaped steering adjustment disk 1, and the movement of the shaped steering adjustment disk 1 changes the blade angle of the steering mechanism 2.

[0026] The directional adjustment mechanism 2 is the execution part that generates flight actions. It includes a rotating shaft 206 for driving the overall rotor system to rotate at high speed. The wing plate 205 is hinged to the upper end of the rotating shaft 206 through the rotor blade clamp 207. The wing plate 205 rotates under the drive of the rotating shaft 206 to generate lift. The irregular directional adjustment disk 1 is sleeved on the outer periphery of the rotating shaft 206. There is a relative movement gap between the irregular directional adjustment disk 1 and the rotating shaft 206, so that the irregular directional adjustment disk 1 can rise and fall along the axial direction of the rotating shaft 206 and can tilt around a direction perpendicular to the axis.

[0027] The innovation of this solution lies in the compact and high-efficiency design of the servo mechanism 3, such as... Figure 4As shown, the servo mechanism 3 is described in detail: The servo mechanism 3 includes a servo bracket 303 serving as the mounting reference. The servo bracket 303 is fixedly connected to the non-rotating part of the mechanism to ensure a stable reaction force base point when the servo is working. The miniature servo 302 is mounted and fixed to the servo bracket 303 by bolts or snap-fit, and is used to receive external control signals and output precise angular displacement. The transmission chain inside the servo mechanism 3 consists of a spherical bent tie rod 304 and a spherical nut 305. One end of the spherical bent tie rod 304 is connected to the miniature servo servo. The output end of 302 is rotatably connected, and its other end is rotatably connected to the ball nut 305; the ball nut 305 is finally firmly fixed to the lower surface of the irregular-shaped deflection adjustment plate 1; this series of precise connections constitutes a complete and short control transmission path. When the micro servo motor 302 moves, the swing of its output end will directly drive the spherical bent tie rod 304 to produce a pushing or pulling action, and transmit this action to the irregular-shaped deflection adjustment plate 1 without loss through the ball nut 305, thereby accurately controlling the irregular-shaped deflection adjustment plate 1 to achieve lifting or tilting.

[0028] Please refer to Figure 3 The steering mechanism 2 also includes a steering pile 202 and a central coupling 203 as a connecting rod. The steering pile 202 is fixedly connected to the upper rotating part of the irregular steering adjustment disk 1, which can rotate together with the rotating shaft 206. One end of the central coupling 203 is rotatably connected to the steering pile 202, and the other end is rotatably connected to the rotor clamp 207, thereby establishing a bridge for motion transmission between the irregular steering adjustment disk 1 and the rotor clamp 207.

[0029] During assembly and operation, when the servo mechanism 3 drives the irregular directional adjustment disk 1 to tilt, the steering pile 202, which rotates together with the irregular directional adjustment disk 1, will generate periodic up-and-down reciprocating motion in the plane of rotation. This motion is directly transmitted to the rotor clip 207 through the central coupling 203, forcing the rotor clip 207 to carry the wing plate 205 to undergo periodic angular changes around its own axis. This ingenious linkage structure ensures that every tiny tilt attitude of the irregular directional adjustment disk 1 can be converted into periodic pitch changes of the wing plate 205 without delay and proportionally. This is the key to achieving agile flight of the unmanned helicopter.

[0030] As a further enhancement to the stability of the directional mechanism 2, such as Figure 3As shown, the steering mechanism 2 also includes a protective frame 201 and a rotor head guide wheel 204; the protective frame 201 is fixedly installed on the top of the steering mechanism 2, the rotor head guide wheel 204 is installed inside the protective frame 201, and the rim of the rotor head guide wheel 204 slides in contact with a designated position on the upper surface of the wing plate 205. This arrangement uses the rotor head guide wheel 204 to reliably limit the movement trajectory of the wing plate 205, effectively preventing the wing plate 205 from swinging undesirably during high-speed rotation, thereby ensuring the stability of flight; As an optimization of the structure of the irregular steering adjustment disk 1, the irregular steering adjustment disk 1 consists of a non-rotating part connected to the ball nut 305 and a rotating part connected to the coupling 203. Its non-rotating part receives control input from the servo mechanism 3, and its rotating part rotates together with the rotating shaft 206. The non-rotating part and the rotating part achieve relative rotation through the bearing. The structure cleverly separates the static control action from the rotating execution component. As a concrete implementation of the transmission flexibility of the servo mechanism 3, such as Figure 4 As shown, the spherical curved tie rod 304 is a rigid rod with a preset curvature. The specific curvature design allows it to cleverly avoid other components when transmitting push and pull forces and leaves sufficient space for movement, ensuring the flexibility and non-interference of the adjustment process. Similarly, refer to Figure 4 To achieve omnidirectional adjustment, the ball joint connection between the ball nut 305 and the ball-shaped bent tie rod 304 is formed. This connection method allows the ball-shaped bent tie rod 304 to swing with multiple degrees of freedom relative to the irregular directional adjustment disc 1, which can perfectly adapt to the complex spatial angle changes during the control process and ensure smooth power transmission without jamming. To ensure the energy supply and layout rationality of the entire control mechanism, such as Figure 4 As shown, the servo mechanism 3 also includes a battery 301 as a power source, and a mounting bracket 306 specifically for mounting and securing the battery 301. The mounting bracket 306 is located adjacent to the servo bracket 303, which allows the power supply and actuator to be arranged in a concentrated manner, which is beneficial for weight balance and wiring simplification. To facilitate the assembly of this mechanism with the main body of the drone, the mechanism is also equipped with a connecting ring 307 and a connecting plate 308. The connecting plate 308 is fixed to the base of the mechanism, while the connecting ring 307 is used to achieve quick assembly and disassembly with the drone body, which greatly improves the convenience of installation and maintenance.

[0031] Working principle: When the unmanned helicopter needs to adjust its flight attitude, the control system sends an adjustment signal to the miniature servo motor 302 in the servo mechanism 3. The entire mechanism is powered by the battery 301 fixed on the mounting bracket 306. After receiving the signal, the miniature servo motor 302 mounted on the servo bracket 303 immediately generates a precise displacement at its output end, directly driving the spherical bent tie rod 304 rotatably connected to it to move. The spherical bent tie rod 304 then transmits the thrust or pull force to the spherical nut 305 fixed on the lower surface of the irregular directional adjustment disc 1 through the ball joint connection at its other end, thereby driving the irregular directional adjustment disc 1 to rise or fall or tilt along the axis of the rotating shaft 206.

[0032] The attitude change of the irregular-shaped directional adjustment disk 1 is transmitted to the high-speed rotating rotor clip 207 through its rotating part and steering pile 202 via the coupling 203 without delay. When the irregular-shaped directional adjustment disk 1 is tilted, the rotor clip 207 will periodically oscillate back and forth as it rotates one revolution with the rotating shaft 206, guided by the coupling 203. This drives the wing plate 205 to periodically adjust its angle around its own axis, thus achieving periodic pitch change. During this process, the rotor head guide wheel 204 located in the protective frame 201 continuously limits the movement trajectory of the wing plate 205 to ensure its stability.

[0033] Through the direct and compact transmission design between the servo mechanism 3 and the irregularly shaped steering adjustment disc 1, this utility model effectively shortens the control response chain. The structure of the spherical bent tie rod 304 and the spherical nut 305 realizes flexible and precise motion transmission. Finally, it is integrated with the UAV fuselage through the connecting ring 307 and the connecting plate 308, which solves the problems of slow response, large size and inconvenient assembly caused by the complex structure of the control mechanism and the long transmission chain in the prior art.

Claims

1. A cyclic pitch control mechanism for an unmanned helicopter, comprising: The steering mechanism (2) includes a shaft (206) for driving the wingplate (205) to rotate, and a rotor clip (207) hinged to the root of the wingplate (205). A non-standard directional adjustment disc (1) is sleeved on the outer periphery of the rotating shaft (206) and can move up and down along the axial direction of the rotating shaft (206) and tilt around a direction perpendicular to the axis. Its features are, The unmanned helicopter cyclic pitch control mechanism further includes a servo mechanism (3), which includes a servo bracket (303) fixedly connected to the non-rotating part of the mechanism, and a miniature servo servo (302) mounted on the servo bracket (303). The servo mechanism (3) further includes a spherical bent tie rod (304) and a spherical nut (305). One end of the spherical bent tie rod (304) is rotatably connected to the output end of the micro servo motor (302), and the other end is rotatably connected to the spherical nut (305). The spherical nut (305) is fixedly connected to the lower surface of the irregular-shaped steering adjustment disc (1). The micro servo motor (302) drives the irregularly shaped steering adjustment disk (1) to generate displacement via the spherical bent tie rod (304) and spherical nut (305).

2. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The steering mechanism (2) also includes a steering pile (202) and a coupling (203) that transmits the motion of the irregular steering adjustment disk (1) to the rotor clip (207). One end of the coupling (203) is rotatably connected to the steering pile (202), and the other end is rotatably connected to the rotor clip (207).

3. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The steering mechanism (2) further includes a protective frame (201) and a rotor head guide wheel (204). The protective frame (201) is fixedly installed on the top of the steering mechanism (2). The rotor head guide wheel (204) is installed inside the protective frame (201) and slides in contact with the wing plate (205) at a designated position to limit the movement trajectory of the wing plate (205).

4. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The spherical curved tie rod (304) is a rigid rod with a preset curvature.

5. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The ball joint connection between the ball nut (305) and the ball-shaped bent tie rod (304) allows the ball-shaped bent tie rod (304) to swing with multiple degrees of freedom relative to the irregular directional adjustment disc (1).

6. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The servo mechanism (3) also includes a battery (301) as a power source, and a mounting bracket (306) for mounting and fixing the battery (301), the mounting bracket (306) being disposed adjacent to the servo bracket (303).

7. The unmanned helicopter cyclic pitch control mechanism according to claim 1, characterized in that, The mechanism also includes a connecting ring (307) and a connecting plate (308) for mounting the entire assembly to the drone fuselage. The connecting plate (308) is fixed to the base of the mechanism, and the connecting ring (307) is used to enable quick assembly and disassembly with the drone fuselage.

8. The unmanned helicopter cyclic pitch control mechanism according to claim 2, characterized in that, The irregular-shaped reversing adjustment disc (1) includes a non-rotating part connected to the ball nut (305) and a rotating part connected to the coupling (203). The rotating part and the non-rotating part rotate relative to each other through a bearing.

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