Mechanical vibration reduction system for high-frequency angle deflection of trailing edge flap

Abstract

The invention belongs to a flight control device in the technical field of aviation, and relates to a trailing edge flap high-frequency angle deflection mechanical vibration reduction system which is composed of a trailing edge flap, a sliding rail, a sliding block, a connecting rod, a transmission rod, an eccentric wheel, an optical axis, a gear set, a servo motor, a deep groove ball bearing, a thrust ball bearing, a linear bearing, a clamping spring and a mechanism fixing base. And other parts of the fastening screw. The servo motor drives the gear set to rotate at different frequencies according to requirements and drives the eccentric wheel to rotate. The eccentric wheel converts rotary motion into reciprocating motion through a connecting rod mechanism composed of a connecting rod and a transmission rod; then, the reciprocating motion is transmitted through a linear guide rail mechanism composed of a sliding block and a sliding rail, the vertical displacement of the trailing edge flap is compensated, finally, the trailing edge flap conducts reciprocating angle deflection at the set frequency, and local lift force and torque distribution are changed. As the servo motor is adopted to drive a pure mechanical structure to execute actions, high-frequency dynamic adjustment can be realized, periodic aerodynamic load fluctuation is counteracted, and fuselage vibration is reduced.

Description

Technical Field

[0001] The present invention is applied to the field of aviation technology, and particularly relates to a mechanical vibration damping system for high-frequency angular deflection of a trailing edge flap. Background Art

[0002] As an important aviation tool, helicopters are widely used in military, civilian, and general aviation fields. Their unique vertical takeoff and landing and hovering capabilities give them irreplaceable advantages in tasks such as rescue, transportation, and reconnaissance. However, the rotor vibration problem of helicopters has always been a key factor affecting their performance and safety. Rotor vibration not only reduces the comfort of passengers and crew but also seriously affects the reliability of on-board equipment, the fatigue life of the airframe structure, and the flight safety of the mechanical vibration damping system for high-frequency angular deflection of the trailing edge flap.

[0003] During the flight of a helicopter, especially during low-altitude, low-speed flight or in complex meteorological conditions, the rotor vibration problem is more prominent. For example, in complex meteorological conditions, a helicopter may face challenges such as wind shear, icing, and low visibility, which will further exacerbate the rotor vibration. In addition, when a helicopter performs repeated takeoff and landing operations (such as RLO flight), due to its special flight environment at low altitude and low speed, the vibration problem will also significantly increase the flight risk. Against this background, in order to effectively solve the helicopter rotor vibration problem, a mechanical vibration damping system for high-frequency angular deflection of the trailing edge flap has emerged. The American Bell Company has achieved significant vibration suppression effects using piezoelectric stack structures, and the "Blue Pulse" project of the European Airbus Helicopters has also successfully demonstrated the advantages of this technology in noise reduction and vibration damping. In 2019, a domestic research institution completed the hover and forward flight experimental verification of active control of the trailing edge flap, proving the application potential of this technology in China. Most of them use piezoelectric materials to achieve small-range changes, but they have poor temperature stability, low mechanical strength, and problems such as fatigue failure and nonlinear distortion under high-frequency vibration or long-term use.

[0004] The present invention realizes the high-frequency angular deflection of the trailing edge flap through a mechanical structure, generates high-order aerodynamic harmonics to offset the vibration load of the blade to achieve the purpose of mechanical vibration damping, and the mechanical structure can more stably and efficiently achieve angular deflection at a fixed frequency, improving the service life of the system. This vibration damping method suppresses helicopter vibration from the source, significantly improving the flight stability and safety. Summary of the Invention

[0005] Aiming at the above problems, the present invention aims to overcome the problems of poor mechanical strength, reliability, energy loss, and environmental adaptability brought about by piezoelectric drive in the prior art. By means of a mechanical vibration damping system, the same purpose is achieved, reducing the severe vibration brought by the helicopter rotor during flight and improving the service life of the airframe structure.

[0006] To achieve the above object, the present invention provides a high-frequency angular deflection of a trailing edge flap, including a trailing edge flap, a servo motor, a linear guide mechanism, an eccentric wheel, a gear set, a connecting rod, a transmission rod, a deep groove ball bearing, a thrust ball bearing, a linear bearing, a smooth shaft, a snap ring, and a mechanism fixing base. When the helicopter is flying or hovering, the servo motor drives the gear set to rotate at a required fixed frequency. Through the transmission of the eccentric wheel and the link mechanism, under the compensation of the linear guide mechanism, the trailing edge flap rotates around a fixed axis at a high frequency and dynamically deflects by a certain angle, generating an additional aerodynamic force, that is, a high-order aerodynamic harmonic, to cancel the vibration load of the blade, achieving stable flight and reducing vibration.

[0007] Furthermore, the damping system designs the mechanism fixing base as an I-shaped structure with small mass and high strength, reducing the position offset of the mechanism caused by the inertial effect of the rotating rotor, improving the stability of the structure, and avoiding the bending deformation of the rotor caused by excessive mass.

[0008] Furthermore, voids are arranged on the mechanism fixing base for placing the smooth shaft and the bearings. Under the assembly of the deep groove ball bearing and the thrust ball bearing, the gear set can rotate efficiently at a fixed speed, reducing the friction generated during rotation and improving the service life of the mechanism.

[0009] Furthermore, under the action of the transmission gear set, the link mechanism composed of the connecting rod and the transmission rod realizes a linear reciprocating motion at a fixed frequency. A linear bearing is installed in the connecting rod limit hole of the mechanism fixing base, reducing the friction between the base and the connecting rod caused by the high-frequency reciprocating motion and improving the service life of the mechanism.

[0010] Furthermore, under the reciprocating motion of the link mechanism, the linear guide mechanism is connected to compensate for the up and down motion vacancy caused by the reciprocating motion, so as to achieve the effect that the trailing edge flap rotates around the fixed smooth shaft at a high frequency and dynamically deflects by a certain angle. Description of the Drawings

[0011] Figure 1 is a schematic assembly diagram of the mechanical damping system for high-frequency angular deflection of the trailing edge flap and the trailing edge flap

[0012] Figure 2 is a schematic diagram of the parts of the mechanical damping system for high-frequency angular deflection of the trailing edge flap

[0013] Figure 3 is a partial enlarged view of the mechanical damping system device for high-frequency angular deflection of the trailing edge flap

[0014] Figure 4 is a diagram of the mechanical damping system based on the rotor position

[0015] Reference numerals in the figure: 1 - trailing edge flap, 2 - connecting rod, 3 - transmission rod, 4 - driven wheel, 5 - servo motor, 6 - mechanism fixing base, 7 - eccentric wheel, 8 - slider, 9 - linear bearing, 10 - slide rail, 11 - set screw, 12 - driving wheel, 13 - transmission wheel, 14 - circlip, 15 - bolt, 16 - connecting optical rod bolt, 17 - deep groove ball bearing, 18 - thrust ball bearing, 19 - optical axis, 20 - rotor blade. Specific implementation manner

[0016] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in detail below. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners:

[0017] This vibration damping system mainly consists of components such as a trailing edge flap, a connecting rod mechanism, a transmission gear set, a servo motor, a mechanism fixing base, an eccentric wheel, a linear guide rail mechanism, a linear bearing, a circlip, a deep groove ball bearing, a thrust ball bearing, and an optical axis.

[0018] When the helicopter is in flight or hovering state, after receiving an instruction, the servo motor drives the gear set at different frequencies according to requirements, causing it to rotate and driving the eccentric wheel to rotate. The eccentric wheel then converts the rotational motion into a reciprocating motion through the connecting rod mechanism composed of a connecting rod and a transmission rod. This reciprocating motion is then transmitted to the linear guide rail mechanism composed of a slider and a slide rail to compensate for the up and down displacement of the trailing edge flap, realizing the high-frequency dynamic deflection of the trailing edge flap around a fixed axis, and the deflection angle is precisely controllable. This process can generate additional aerodynamic forces (i.e., high-order aerodynamic force harmonics), effectively canceling the vibration loads of the rotor blades, and thus achieving the goals of stable flight and vibration damping. To enhance the stability and durability of the system, the present invention has optimized the design of key components. The mechanism fixing base adopts a lightweight and high-strength I-shaped structure, significantly reducing the influence of the inertial force during rotor rotation on the position of the mechanism, and at the same time avoiding the bending deformation of the rotor caused by the excessive mass of the base. Specific cavities are designed on the base for accurately placing the optical axis and bearings, ensuring a compact layout of components and efficient transmission. The gear set, under the collaborative assembly of deep groove ball bearings and thrust ball bearings, can achieve efficient and low-friction rotation at a fixed rotational speed, effectively extending the service life of the mechanism. The connecting rod mechanism, driven by the transmission gear set, realizes a linear reciprocating motion at a fixed frequency, and the friction during its motion process is further reduced by the linear bearing, significantly improving the durability of the mechanism. In addition, the reciprocating motion of the connecting rod mechanism drives the linear guide rail mechanism to compensate for the up and down motion gaps generated by the reciprocating motion, ensuring that the trailing edge flap can accurately achieve high-frequency dynamic deflection around a fixed optical axis, efficiently generate additional aerodynamic forces, and cancel the vibration loads.

[0019] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap is designed to solve the problem that the helicopter rotor will produce periodic aerodynamic load fluctuations in different flight states, such as hovering, forward flight, turning, etc., thus generating vibrations that affect the structure of the fuselage. It can also reduce resistance during high-speed flight and maintain stability in complex airflow. The system includes: Trailing edge flap (1), servo motor (5), slide rail (10), slider (8), eccentric wheel (7), driving wheel (12), transmission wheel (13), driven wheel (4), connecting rod (3), transmission rod (2), deep groove ball bearing (17), thrust ball bearing (18), linear bearing (9), optical axis (19), retaining spring (14), mechanism fixing base (6).

2. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 1, characterized in that The size of the mechanism fixing base (6) is designed according to the internal structure of the rotor, and an I-shaped structure is adopted to make the structure more firmly embedded in the rotor, thereby preventing the system from forming an angle deflection.

3. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 1, characterized in that The gear train transmission is designed to adapt to the problem of narrow internal space of the rotor, wherein the driving wheel (12) is fixed on the servo motor (5) to achieve variable frequency rotation, and through the gear train transmission, the driven wheel drives the connecting rod mechanism to achieve reciprocating motion.

4. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 1, characterized in that The eccentric wheel is driven by the gear set to realize the movement of the transmission rod around the polished rod bolt on the eccentric wheel (7), and the transmission rod (3) is connected to the connecting rod (2). The linear bearing (9) on the fixed base (6) is used to realize the periodic reciprocating motion of the connecting rod (2).

5. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 1, characterized in that Under the reciprocating motion of the connecting rod (3), the linear guide mechanism formed by the slide rail (10) and the slider (8) compensates for the up and down motion of the trailing edge flap, so that the trailing edge flap can achieve high-frequency angular deflection.

6. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 3, characterized in that In the gear set structure, the transmission wheel (13) is fixed on the base, and a deep groove ball bearing (17) and a thrust ball bearing (18) are nested inside. The inner ring of the deep groove ball bearing (17) is interference fit with the protruding part of the base, and the outer ring is interference fit with the gear. The thrust ball bearing (18) limits the radial position of the gear and reduces the friction of the gear connection part. At the same time, a retaining spring (14) is used on the outer side of the gear to determine the radial position.

7. The high-frequency angle deflection mechanical vibration reduction system of the trailing edge flap according to claim 4, characterized in that A linear bearing is used between the base (6) and the connecting rod (3) to reduce friction caused by reciprocating motion and increase the service life of the entire system.

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