Helicopter blade trailing edge flap drive mechanism using flexible hinge

Abstract

The invention discloses a helicopter blade trailing edge flap driving mechanism using a flexible hinge, comprising a fixed frame, a driver, a trailing edge flap, a flap flexible hinge, a bearing, a driving rod and a driving rod flexible hinge. The driver generates a high-frequency linear displacement output to drive the trailing edge flap to deflect; one end of the flap flexible hinge is connected to the trailing edge flap, and the other end is installed on the fixed frame, and the flap flexible hinge bears the centrifugal load of the flap when the rotor is rotating; a bearing is installed between the trailing edge flap and the fixed frame, and its function is to constrain the floating and sinking movement of the trailing edge flap; the driving rod transmits the driver linear displacement output to the trailing edge flap, and converts the driver's linear displacement into the deflection movement of the trailing edge flap through the flap flexible hinge, the driving rod flexible hinge and the bearing. The invention is used to drive the trailing edge flap to dynamically deflect, generate additional aerodynamic load to suppress rotor vibration, and thus realize active control of helicopter rotor vibration.

Description

Technical Field

[0001] The invention belongs to the intelligent rotor technology in the field of helicopter rotor vibration control, and in particular relates to a trailing edge flap driving mechanism suitable for a trailing edge flap intelligent rotor. Background Art

[0002] Helicopters have the characteristics of efficient hovering and low-speed forward flight that fixed-wing aircraft do not have, and have been widely used in military and civilian fields. However, due to the complexity of the working environment of helicopter rotors, the vibration level of helicopters is generally higher than that of contemporary fixed-wing aircraft. High vibration levels not only affect the comfort of drivers and passengers, but also have adverse effects on fuselage components and onboard equipment, reducing their reliability or service life. In order to suppress the vibration load brought by helicopter rotors, some active helicopter models have adopted passive vibration suppression measures, such as centrifugal pendulum dynamic vibration absorbers and dual-line pendulum dynamic vibration absorbers. However, passive vibration control measures in the form of dynamic vibration absorbers generally have shortcomings such as large additional mass and single vibration reduction frequency. Passive vibration control measures are difficult to adapt to the increasingly stringent helicopter vibration level requirements.

[0003] With the continuous development of helicopter technology and the improvement of drive technology, active vibration control technology applied to helicopter rotors has emerged. So far, the active vibration control technologies applied to helicopter rotors include: high-order harmonic control acting on the fixed ring of the automatic tilt device, independent blade control acting on the pitch lever, trailing edge flap smart rotor with the driver located on the blade, and active twisting rotor. The technical implementation methods of these active vibration control measures applied to the rotor are different, and the actuator types and installation positions are different, but the principles of their vibration control are similar, all of which dynamically change the load distribution of the rotor blades during one rotation to suppress part of the rotor vibration load. Among these different active vibration control technologies, the trailing edge flap smart rotor has become a hot spot in the research of rotor vibration control technology due to its relatively simple structure and higher reliability and safety than other active vibration control technologies, and has a higher engineering application prospect under current technical conditions. The trailing edge flap smart rotor generates additional aerodynamic loads through the high-frequency active deflection of the flap installed on the trailing edge of the helicopter blade, changes the distribution of the blade load at different azimuths, and thus achieves the purpose of suppressing the rotor vibration load. Since the trailing edge flap intelligent rotor drive mechanism is installed in the rotor blades and has no direct connection with the helicopter control system, the extreme situation of trailing edge flap failure will not endanger the control of the helicopter. It is safer than other forms of rotor vibration active control technology.

[0004] The driving mechanism of the trailing edge flap plays an important role in the design process of the trailing edge flap intelligent rotor. Whether the driving mechanism can work reliably and stably determines the vibration control effect of the trailing edge flap intelligent rotor. Since the trailing edge flap works in a strong centrifugal field environment during the rotation of the rotor, the driving mechanism of the trailing edge flap must be able to withstand the centrifugal load caused by the mass of the flap; the trailing edge flap is supported by a bearing, and the bearing must consider lubrication and overcome the centrifugal load of the trailing edge flap. In the case of poor lubrication, the centrifugal force of the trailing edge flap will cause a series of adverse consequences such as excessive bearing friction, increased power consumption, and limited deflection of the trailing edge flap, reducing the active deflection ability of the trailing edge flap. Due to the limitation of the thickness of the trailing edge of the helicopter rotor blade airfoil, it is difficult to arrange the thrust bearing commonly used in mechanical design to withstand the centrifugal load of the flap. Summary of the invention

[0005] In order to solve the problems in the above-mentioned prior art, the present invention proposes a trailing edge flap drive mechanism using a flexible hinge for a trailing edge flap intelligent rotor blade, which is used to drive the trailing edge flap to dynamically deflect under a centrifugal force field, and change the load distribution of the rotor at different azimuth angles through the deflection of the flap, thereby achieving the purpose of suppressing vibration loads.

[0006] The invention discloses a helicopter blade trailing edge flap driving mechanism adopting a flexible hinge, comprising a trailing edge flap, a driving rod flexible hinge, a flap flexible hinge, a fixing frame, a driver, a driving rod, an outer fixing block, an inner fixing block, a flap fixing block, a bearing, an optical axis and other components; the front end of the fixing frame is bonded and fixed to a base blade beam, the lower surface is bonded to a blade skin, and a plurality of threaded holes are reserved on the upper surface for fixing a maintenance cover of the driving mechanism; one end of the driver is mounted on the fixing frame through a thread, and the other end is connected to the driving rod; the driving rod flexible hinge connects the driving rod and the trailing edge flap; a flap flexible hinge is installed between the trailing edge flap and the fixing frame to bear the centrifugal load of the trailing edge flap; a bearing is set between the trailing edge flap and the outer fixing block to restrict the floating and sinking movement of the trailing edge flap, and the outer fixing block is fixed to the fixing frame through bolts.

[0007] As a further improvement, the fixing frame is bonded and fixed to the base blade, and is directly connected to the driver, outer fixing block, inner fixing block, flap flexible hinge and other components in the trailing edge flap driving mechanism. During the rotation of the rotor, the centrifugal loads of each component are transmitted to the base blade through the fixing frame.

[0008] As a further improvement, a plurality of threaded holes are reserved on the upper surface of the fixing frame for installing a cover to facilitate the inspection and maintenance of the driving mechanism.

[0009] As a further improvement, the driver adopts piezoelectric material or other forms of intelligent driving materials to generate high-frequency linear displacement output to drive the deflection movement of the trailing edge flap.

[0010] As a further improvement, one end of the driver is mounted on the fixed frame via bolts, and the other end is connected to the driving rod via threads.

[0011] As a further improvement, one end of the driving rod is fixed to the output end of the driver through a thread, and the other end is connected to the driving rod flexible hinge. The driving rod flexible hinge is fixed on the platform of the trailing edge flap to transmit the linear displacement output of the driver to the trailing edge flap.

[0012] As a further improvement, a flap flexible hinge is installed between the fixing frame and the trailing edge flap, one side of the flexible hinge is fixed to the fixing frame through an inner fixing block, and the other side is fixed to the trailing edge flap through a flap fixing block.

[0013] As a further improvement, the flap flexible hinge is made of metal material or non-metal composite material, has low bending stiffness and high shear strength, and can withstand the centrifugal load of the trailing edge flap while ensuring the normal deflection movement of the trailing edge flap.

[0014] As a further improvement, a bearing is arranged between the outer fixing block and the trailing edge flap, the outer ring of the bearing is fixed to the outer fixing block, the optical axis passes through the inner ring of the bearing and is fixed to the optical hole on the trailing edge flap, and the bearing is used to constrain the floating and sinking freedom of the trailing edge flap.

[0015] The working principle of the present invention is:

[0016] Under the excitation of external driving voltage, the driver generates high-frequency linear displacement output and transmits it to the trailing edge flap through the driving rod and the driving rod flexible hinge. A flap flexible hinge made of metal material or non-metallic composite material is installed between the trailing edge flap and the fixed frame. The flexible hinge has small bending stiffness and large shear strength, which can ensure the deflection of the trailing edge flap and withstand the centrifugal load of the flap when the rotor is rotating. A radial bearing is set between the trailing edge flap and the outer fixed block to constrain the floating and sinking movement freedom of the trailing edge flap caused by the bending of the flap flexible hinge, ensuring that the trailing edge flap can only move in a deflection along the axis. The deflection of the trailing edge flap generates additional aerodynamic loads, which changes the distribution of the rotor load along the azimuth angle, thereby suppressing the rotor vibration load.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention adopts a flap flexible hinge made of metal material or non-metallic composite material to connect the trailing edge flap and the fixed frame. While ensuring the deflection freedom of the trailing edge flap, the flap flexible hinge can also withstand the centrifugal load of the trailing edge flap when the rotor is rotating; because the flap flexible hinge has a certain width in the radial direction of the blade, the flexible hinge can also play a certain sealing role, preventing the high-pressure airflow on the lower surface of the blade airfoil from leaking to the upper surface of the blade airfoil through the gap between the flap and the blade, thereby improving the vibration control effect of the trailing edge flap to a certain extent; compared with the solution of using ordinary sliding bearings to withstand the centrifugal load of the flap, the flap flexible hinge proposed by the present invention will not generate friction that hinders the movement of the flap when the flap is deflected, and does not require complicated lubrication and sealing measures; a micro radial bearing is set between the outer fixing block and the trailing edge flap, which is used to constrain the floating and sinking movement freedom of the flap caused by the bending of the flap flexible hinge, and ensure that the trailing edge flap can only deflect at a high frequency and small amplitude along the axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the overall effect diagram of the trailing edge flap drive mechanism using a flexible hinge;

[0020] Figure 2 It is a schematic diagram of the main moving parts of the driving mechanism;

[0021] Figure 3 This is a schematic diagram of the installation of the flap flexible hinge;

[0022] Figure 4 is a schematic diagram of the flap flexible hinge;

[0023] Figure 5 This is a schematic diagram of the bearing installation;

[0024] Figure 6 Schematic diagram of the trailing edge flap.

[0025] Among them, 1-trailing edge flap, 2-driving rod flexible hinge, 3-flap flexible hinge, 4-fixing frame, 5-driver, 6-driving rod, 7-outer fixing block, 8-inner fixing block, 9-flap fixing block, 10-bearing, 11-optical axis, 12-optical hole, 13-platform. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] Example 1

[0028] The present invention provides a helicopter blade trailing edge flap driving mechanism using a flexible hinge, the overall structure of the driving mechanism is as follows: Figure 1As shown, the fixed frame 4, the driving assembly, and the fixed assembly connected to the driving assembly; wherein the driving assembly generates driving force and transmits it to the trailing edge flap;

[0029] The fixing assembly connects the trailing edge flap to the fixing frame and constrains the movement of the trailing edge flap so that the trailing edge flap can only perform deflection movement along its deflection axis.

[0030] The driving assembly and the fixing assembly in the present invention are now further described. Figure 2 As shown, the driving assembly includes a driving rod flexible hinge 2, a driver 5 and a driving rod 6;

[0031] One end of the driver 5 is mounted on the fixed frame 4 by bolts, and the other end is connected to the driving rod 6; the driving rod 6 transmits the linear displacement output of the driver 5 to the trailing edge flap 1 through the driving rod flexible hinge 2; the driving rod flexible hinge 2 is connected to the platform 13 of the trailing edge flap 1.

[0032] like Figure 3 , Figure 4 As shown, the fixing assembly includes a flap flexible hinge 3, an outer fixing block 7, an inner fixing block 8 and a flap fixing block 9; an inner fixing block 8 and an outer fixing block 7 are provided on both sides of the driving rod flexible hinge 2 from the inside to the outside, and the outer fixing blocks 7 on both sides are symmetrically fixed on the fixing frame 4 to connect the fixing frame 4 with the trailing edge flap 1; a flap flexible hinge 3 is also installed between the fixing frame 4 and the trailing edge flap 1, and the flap flexible hinge 3 is fixed to the fixing frame 4 through the inner fixing block 8.

[0033] As a preferred embodiment, a plurality of threaded holes are reserved on the upper surface of the fixing frame 4 for installing a cover to facilitate the inspection and maintenance of the driving mechanism. The driver 5 is made of piezoelectric material to generate a high-frequency linear displacement output to drive the trailing edge flap to perform a high-frequency small-amplitude deflection movement. The flap flexible hinge 3 is a thin sheet structure made of metal material or non-metal composite material, such as a spring steel sheet or a carbon fiber sheet, which has the characteristics of low bending stiffness and high shear strength.

[0034] like Figure 5 As shown, a bearing 10 is arranged between the outer fixing block 7 and the trailing edge flap 1, the outer ring of the bearing 10 is fixed to the outer fixing block 7, the optical axis 11 passes through the inner ring of the bearing and is fixed to the optical hole 12 on the trailing edge flap, and the bearing is used to constrain the floating and sinking freedom of the trailing edge flap.

[0035] The helicopter blade trailing edge driving mechanism using a flexible hinge disclosed in the present invention is used to drive the trailing edge flap deflection movement, and its main components include: 1 trailing edge flap, 2 driving rod flexible hinge, 3 flap flexible hinge, 4 fixing frame, 5 driver, 6 driving rod, 7 outer fixing block, 8 inner fixing block, 9 flap fixing block, 10 bearing, 11 optical axis;

[0036] Among them, the fixing frame 4 is bonded and fixed to the base blade, and other components in the trailing edge flap driving mechanism are directly or indirectly mounted on the fixing frame 4; one end of the driver 5 is fixed to the fixing frame 4 by bolts, and the other end is connected to the driving rod 6 by threads; one end of the driving rod 6 is connected to the driver, and the other end is connected to the driving rod flexible hinge 2, and the driving rod flexible hinge 2 is installed on the platform 13 of the trailing edge flap 1 by screws, and the high-frequency linear displacement output generated by the driver 5 is transmitted through the driving rod 6 and the driving rod flexible hinge 2 to the trailing edge flap 1 located at the trailing edge of the blade; a flap flexible hinge 3 made of metal material or non-metal composite material is installed between the trailing edge flap 1 and the fixing frame 4, on one side of the trailing edge flap 1, the flap flexible hinge 3 is fixed by the flap fixing block 9, and on one side of the fixing frame 4, the flap flexible hinge 3 is fixed by the inner fixing block 8; a bearing 10 is set between the outer fixing block 7 and the trailing edge flap 1, the outer ring of the bearing 10 is fixed to the outer fixing block 7, and the optical axis 11 passes through the inner ring of the bearing and is fixed to the optical hole 12 on the trailing edge flap.

[0037] Through the above structural design, the present invention solves the following problems:

[0038] 1) The vibration load frequency of a helicopter is usually an integer multiple of the rotor speed, so the trailing edge flap needs to make a small deflection motion at a higher frequency to generate an additional aerodynamic load of the corresponding frequency to offset the rotor vibration load;

[0039] 2) Trailing edge flaps are usually made of lightweight materials. Although their structural mass is relatively light, they still generate considerable centrifugal loads during the rotation of the rotor. Certain mechanical components are required to withstand this centrifugal load, while at the same time these components do not generate large friction forces that hinder the deflection of the flaps.

[0040] 3) There is a gap between the trailing edge flap and the base blade. The high-pressure airflow on the lower surface of the blade will leak through the gap to the upper surface of the blade, thereby reducing the additional aerodynamic load generated by the trailing edge flap and reducing the vibration control performance of the trailing edge flap rotor.

[0041] 4) When the flap flexible hinge is bent and deformed, there are two forms of motion, linear displacement and angular displacement, at the connection between the flap flexible hinge and the trailing edge flap. This causes the flap to float and sink while deflecting, which is not conducive to the normal operation of the flap drive mechanism and makes the flap deflection angle measurement more difficult.

[0042] Example 2

[0043] The present invention provides a connection and fixing scheme for applying the above-mentioned driving mechanism to helicopter blades. Based on the above-mentioned driving mechanism, the fixing frame 4 is adhesively fixed to the base blade, and is directly connected to the driver 5, the outer fixing block 7, the inner fixing block 8, the flap flexible hinge 3 and other components in the trailing edge flap driving mechanism. During the rotation of the rotor, the centrifugal loads of each component are transmitted to the base blade through the fixing frame.

[0044] Therefore, this patent proposes a helicopter blade trailing edge flap drive mechanism design in the form of a flexible hinge, which bears the centrifugal load of the flap through the flexible hinge, and limits the floating and sinking movement freedom of the trailing edge flap caused by the bending of the flexible hinge through a micro radial bearing, thereby achieving stable and reliable operation of the trailing edge flap under the action of a strong centrifugal force field.

[0045] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A helicopter blade trailing edge flap drive mechanism using a flexible hinge, characterized in that: The driving mechanism comprises a fixing frame (4), a driving component, and a fixing component connected to the driving component; wherein the driving component generates a driving force for driving the trailing edge flap to dynamically deflect; The fixing assembly connects the trailing edge flap to the fixing frame and constrains the movement of the trailing edge flap so that the trailing edge flap can only perform deflection movement along its deflection axis; The driving assembly comprises a driving rod flexible hinge (2), a driver (5) and a driving rod (6); One end of the driver (5) is mounted on the fixing frame (4) by means of bolts, and the other end is connected to the driving rod (6); the driving rod (6) and the driving rod flexible hinge (2) transmit the linear displacement output of the driver (5) to the trailing edge flap (1); The drive rod flexible hinge (2) is connected to the platform (13) of the trailing edge flap (1); The fixing assembly comprises a flap flexible hinge (3), an outer fixing block (7), an inner fixing block (8) and a flap fixing block (9); the inner fixing block (8) and the outer fixing block (7) are arranged on both sides of the driving rod flexible hinge (2) from the inside to the outside, and the outer fixing blocks (7) on both sides are symmetrically fixed on the fixing frame (4) to connect the fixing frame (4) with the edge flap (1); A flap flexible hinge (3) is also installed between the fixing frame (4) and the trailing edge flap (1), and the flap flexible hinge (3) is fixed to the fixing frame (4) via an inner fixing block (8); A bearing (10) is arranged between the outer fixing block (7) and the trailing edge flap (1), the outer ring of the bearing (10) is fixed to the outer fixing block (7), the optical axis (11) passes through the inner ring of the bearing and is fixed to the optical hole (12) on the trailing edge flap, and the bearing is used to constrain the floating and sinking freedom of the trailing edge flap; When the driving mechanism is applied to a helicopter blade, the fixing frame (4) is bonded and fixed to the base blade, and is directly connected to components such as a driver (5), an outer fixing block (7), an inner fixing block (8), and a flap flexible hinge (3) in the trailing edge flap driving mechanism. During the rotation of the rotor, the centrifugal loads of each component are transmitted to the base blade through the fixing frame.

2. The helicopter blade trailing edge flap drive mechanism using a flexible hinge according to claim 1, characterized in that: A plurality of threaded holes are reserved on the upper surface of the fixing frame (4) for mounting a cover to facilitate inspection and maintenance of the drive mechanism.

3. The helicopter blade trailing edge flap drive mechanism using a flexible hinge according to claim 2, characterized in that: The driver (5) is made of piezoelectric material and is used to generate a high-frequency linear displacement output, so as to drive the high-frequency small-amplitude deflection movement of the trailing edge flap.

4. The helicopter blade trailing edge flap drive mechanism using a flexible hinge according to claim 1, characterized in that: The flap flexible hinge (3) is a thin sheet structure made of metal material or non-metal composite material, and has the characteristics of low bending rigidity and high shear strength.

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