Driving device based on hydraulic transmission and used for Gurney flap of helicopter

Abstract

The embodiment of the invention discloses a driving device based on hydraulic transmission and used for a gurney flap of a helicopter, relates to the technical field of rotor aircrafts, and can realize variable-height driving of the gurney flap under the condition of ensuring the control precision and stability of the whole device. The mechanical driving device is composed of an electric push rod, a hydraulic system, a gurney flap and a shell of the mechanical driving device. An electric push rod is used for providing original power to drive a piston, the electric push rod drives an input end piston rod, the piston rod acts on liquid in a pipeline embedded in a paddle, the pipeline embedded in the paddle is bent in a flap arrangement area so that a compressed working medium in the pipeline can drive an output end piston, and the output end piston drives the piston rod to press a semi-rigid beam. The gurney flap is actuated by using the stiffening bar. Power is provided for the gurney flap arrangement area, and the purpose of driving the gurney flaps is achieved by driving the connecting rods to rotate. The whole device adopts a negative feedback regulation mechanism and is accurate and stable.

Description

Technical Field

[0001] The present invention relates to the technical field of rotary-wing aircraft, and in particular to a driving device based on hydraulic transmission and used for a Gurney flap of a helicopter. Background Art

[0002] Helicopters use rotors as their main source of lift. Their hovering and vertical take-off and landing capabilities make them widely used. Related improvements are also constantly being made, and one of the improvement directions is the improvement of flaps.

[0003] A Gurney flap is a lift-enhancing device installed on the trailing edge of a propeller blade that reduces drag and significantly improves flight performance. However, current research has found that its ability to increase lift and reduce vibration varies depending on the flap's deployment height and the aerodynamic environment.

[0004] Therefore, how to design a variable-height Gurney flap drive solution has become a topic that needs to be studied. Summary of the Invention

[0005] An embodiment of the present invention provides a driving device for a helicopter Gurney flap based on hydraulic transmission, which realizes variable-height driving of the Gurney flap while ensuring the control accuracy and stability of the entire device.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] The driving device is installed on the Gurney flap, and the driving device comprises: an electric push rod (1), an input end piston (2), a flexible conduit (3), a connecting rod (5) and a driving part;

[0008] One end of the electric push rod (1) is a fixed end, which is fixed to the hub of the helicopter Gurney flap. The other end of the electric push rod (1) is connected to the input end piston (2), and the two are fixed to the hub through a fixing device. The other end of the input end piston (2) is a conduit connection end. The electric push rod is directly fixed to the hub to provide power to the piston of the hydraulic system.

[0009] The input end piston (2) is connected to the driving part of the driving device through a flexible conduit (3), and the flexible conduit (3) is connected to the piston structure;

[0010] The driving part is mounted on the Gurney flap, wherein the driving part and the beam of the blade of the Gurney flap are staggered along the chord direction of the blade of the Gurney flap.

[0011] The driving part includes: an output end piston (4), a rigid beam (6), a Gurney flap (7) and a mechanical device housing (8), wherein the mechanical device housing (8) is fixedly connected to the skin of the blade; one end of the output end piston (4) is connected to the flexible conduit (3), and the other end of the output end piston (4) is connected to the rigid beam (6) through a connecting rod (5). When the output end piston (4) moves, the rigid beam (6) is driven to move up and down through the connecting rod (5). In a preferred embodiment, the driving part is installed at a distance of 75% of the radius from the blade to the hub, and the Gurney flap is arranged on the blade, wherein the Gurney flap is arranged at a distance of 80% to 90% of the chord length.

[0012] The electric push rod (1) is connected to the input end piston (2) and is connected to the output end piston (4) through a flexible conduit (3). The flexible conduit (3) is connected to the piston structure, including: the portion of the flexible conduit (3) exposed outside the blade root is the extended side, the extended side is sealed and connected to the input end piston (2) to form a piston-conduit connection; the portion of the flexible conduit (3) extending into the blade is the embedded side, the flexible conduit (3) is arranged along the blade radial direction and passes through the mechanical device housing (8) to be sealed and glued to the output end piston (4); the internal structure of the input end piston (2) and the output end piston (4) is the same, including a piston rod (9), a piston head (10) and a piston cylinder (11), the piston head (10) is installed at the top end of the piston rod (9); a piston ring is installed on the edge of the piston head (10), the side of the piston ring is grooved, the piston rod (9) is installed in the piston cylinder (11), and the piston ring and the inner wall of the piston cylinder (11) cooperate with each other.

[0013] Furthermore, the two ends of the flexible conduit (3) are respectively glued to the top of the piston cylinder (11) of the input end piston (2) and the output end device (4); the portion of the flexible conduit (3) exposed outside the blade is the flexible conduit extension side, and the flexible conduit extension side is sealed and connected to the bottom of the corresponding piston cylinder (11) to form a piston-flexible conduit connection. The flexible conduit (3) extends into the blade at the trailing edge of the blade root, and the portion extending into the blade is the flexible conduit embedded side; a blind hole is opened on the mechanical device housing (8) so that the flexible conduit embedded side passes through the opened blind hole and is then sealed and glued to the output end piston (4) to form a piston-flexible conduit connection. The rigid beam (6) is fixedly connected to the Gurney flap (7) so that the rigid beam (6) drives the Gurney flap (7) to move up and down.

[0014] Furthermore, the cross section of the conduit at the piston-conduit connection is designed with a smooth transition to avoid leakage. The electric push rod (1) and the input end piston (2) are both mounted on the propeller hub; specifically, Figure 2aAs shown, an actuator fixture is pre-welded on the hub. The shape of the mounting hole of the actuator fixture matches the fixed end of the input end piston (2). After the fixed end of the input end piston (2) is inserted into the mounting hole of the actuator fixture, it fits tightly with the mounting hole. A hole is opened on the actuator fixture to facilitate the passage of the flexible conduit (3) and the input end piston rod (2). A limit cover is installed on the edge of the mounting hole of the actuator fixture by bolts. The inner shape of the limit cover matches the cross-section of the input end piston (2). The electric push rod can be extended and retracted by switching the positive and negative poles. A small single-chip microcomputer can be used to achieve this function. In actual application, the extended side of the Green flap can be reserved with a chord length of one percent on the outer side of the skin to obtain good lift performance. A counterweight bar is installed in the blade beam to meet the design requirements of the helicopter blade center of gravity.

[0015] The hydraulically driven drive device for helicopter Gurney flaps provided in an embodiment of the present invention utilizes a single-chip microcomputer to control an electric push rod. The push rod drives an input piston, which pushes the fluid within the piston and flexible conduit to produce work. This work is then applied to the fluid to drive a rigid beam, thereby actuating the Gurney flap. The output piston drives a connecting rod, which in turn drives the rigid beam up and down, thereby retracting and extending the Gurney flap. Therefore, this embodiment can adjust the extended length of the Gurney flap at a given height. The height-adjusting Gurney flap is driven by a hydraulic mechanism, and a negative feedback control system is employed to ensure control accuracy and stable operation of the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. 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 these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of the overall assembly structure of a hydraulically driven Gurney flap drive device provided in an embodiment of the present invention;

[0018] Figure 2a A schematic diagram of the hub and blade root details provided in an embodiment of the present invention;

[0019] Figure 2b A detailed schematic diagram of a piston actuating device provided in an embodiment of the present invention;

[0020] Figure 3 A detailed schematic diagram of a flexible catheter provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the connecting rod details provided by an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of connection details between a rigid beam and a Gurney flap provided in an embodiment of the present invention;

[0023] Figure 6 A detailed schematic diagram of a Gurney flap provided in an embodiment of the present invention;

[0024] Figure 7a A schematic diagram of the external details of a mechanical device provided by an embodiment of the present invention;

[0025] Figure 7b A schematic diagram of the internal details of a rotor equipped with a mechanical device according to an embodiment of the present invention;

[0026] Figure 7c A schematic diagram of the internal details of a mechanical device provided by an embodiment of the present invention;

[0027] Figure 8 A schematic diagram of a push rod-piston connection method provided in an embodiment of the present invention;

[0028] Figure 9 A schematic diagram of the structural principle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention will be described in detail below, with examples of the embodiments illustrated in the accompanying drawings. Throughout, identical or similar reference numerals represent identical or similar elements or elements having identical or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and intended only to explain the present invention and are not to be construed as limiting the present invention. Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" as used in the description of the present invention refers to the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or intervening elements may be present. Furthermore, "connected" or "coupled" as used herein may include wireless connections or couplings. The term "and / or" as used herein includes any and all combinations of one or more associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such herein.

[0030] The design concept of this embodiment is primarily based on the different requirements for the Gurney flap in different flight states, such as forward flight and hovering, and a drive device that can adjust the Gurney flap's height is designed. Specifically, it includes a piston actuator mounted on the propeller hub, a flexible conduit mounted inside the blade, and structures or components such as a piston and connecting rod housed within the mechanical device housing. During operation, the piston drives the connecting rod, which connects the connecting rod to the rigid beam of the Gurney flap to achieve retraction and extension of the Gurney flap. As the piston reciprocates, the volume of the working fluid in the piston cylinder and the flexible conduit changes, causing the connecting rod and rigid beam to deflect, allowing the extended side of the Gurney flap to be retracted and extended perpendicular to the blade chord. The Gurney flap's extended length changes at a certain height. The variable-height Gurney flap is driven by a hydraulic mechanical device and employs a negative feedback control system to ensure control accuracy and stable operation of the entire device. The device designed in this embodiment is actually a negative feedback system, significantly more accurate than systems without feedback. During design, the stability of the control system is calculated based on the Nyquist stability criterion to ensure control accuracy and stable operation of the entire device.

[0031] The driving device of the helicopter Gurney flap designed in this embodiment is based on hydraulic actuation and is used for the helicopter Gurney flap. Figure 1-9 As shown, it includes: an electric push rod (1), an input end piston (2), a flexible conduit (3), an output end piston (4), a connecting rod (5), a rigid beam (6), a Gurney flap (7), and a mechanical device housing (8); the electric push rod (1) and the input end piston (2) are mounted and fixed on the propeller hub, wherein one end of the electric push rod (1) is a fixed end, wherein the fixed end of the electric push rod (1) is fixed on the propeller hub, and the electric push rod is directly fixed on the propeller hub to provide power for the piston of the hydraulic system.

[0032] In actual use, considering the wear of the input end piston (2), its sealing performance will decrease and it needs to be replaced regularly, so a fixture is welded on the hub instead of directly welding the input end piston (2) to the hub. The fixture has holes at the top and bottom to allow the flexible conduit (3) and the piston rod to pass through, and the fixture is connected to the input end piston (2) by bolts. During actual use, the helicopter will produce large vibrations that may loosen the bolts, so the bolts at this location should be included in the pre-flight maintenance plan. In terms of material, the fixture is made of lightweight aluminum alloy.

[0033] The two ends of the flexible conduit (3) are respectively connected to the input end piston (2) and the output end piston (4). One end of the flexible conduit (3) is glued to the top of the input end piston (2), and after a certain length is reserved, it extends into the blade through the root of the blade. Due to the complex structure of the hub, the wiring should be arranged reasonably to prevent interference with the normal operation of the hub. The guide tube can also be arranged according to the hub structure. The skin and the flexible conduit (3) are fixed and bonded with elastic sealant at the trailing edge of the blade root. The flexible conduit (3) is arranged along the radial direction of the blade, passes through the mechanical device housing (8) and is connected to the output end piston (4). In the actual production process, the blade is molded, and the embedded end of the flexible conduit (3) can be made of carbon material to avoid obstruction of its permeability. Hydraulic oil is contained in the flexible conduit as a driving medium. When the electric push rod (1) pushes the input end piston (2), it is worked to drive the output end piston (4), so that the connecting rod (5) and the rigid beam (6) move, thereby driving the Gurney flap to move up and down.

[0034] The piston rod of the output end piston (4) is welded to the connecting rod (5) so that the two can move simultaneously. The connecting rod (5) is welded to the rigid beam (6). When the connecting rod (5) moves, the rigid beam (6) can be driven to move up and down. The rigid beam (6) is fixedly connected to the Gurney flap (7). When the rigid beam (6) moves up and down, the Gurney flap (7) can be retracted and extended. The above-mentioned input end piston (2), output end piston (4), connecting rod (5), Gurney flap (7) and mechanical device housing (8) are all made of aluminum alloy.

[0035] A micro displacement sensor is provided, the circuit of which is consistent with the flexible conduit (3), for providing a feedback signal. The onboard fly-by-wire control system drives the electric push rod (1), and uses the micro displacement sensor to calculate and measure the deflection angle of the Gurney flap (7) to feed back to the onboard fly-by-wire control system. The sensor can be used to feed back the deflection angle of the Gurney flap.

[0036] Optionally, a counterweight strip is installed in the blade beam to meet the design requirements of the blade's center of gravity. The connecting rod (5), rigid beam (6), Gurney flap (7) and mechanical device housing (8) are all made of aluminum alloy. After the entire structure is connected and installed, the device in the skin can be arranged at its designed position and molded together with the edge guard strip, beam and filling material.

[0037] The embodiment of the present invention discloses a driving device for helicopter Gurney flaps based on a hydraulic transmission method different from the existing technical solutions, which relates to the technical field of rotorcraft. According to the different requirements for Gurney flaps in different flight states such as forward flight and hovering of helicopters, a driving system that can adjust the height of Gurney flaps is designed. It can change the height of the Gurney flaps in the vertical chord direction. In the present invention, it is composed of an electric push rod, a hydraulic system, a Gurney flap and a shell of a mechanical drive device. The electric push rod is used to provide original power to drive the piston, and the electric push rod drives the input end piston rod. The piston rod does work on the liquid in the pipe embedded in the blade. The pipe embedded in the blade is bent in the flap arrangement area so that the compressed working fluid in the pipe drives the output end piston. The output end piston drives the piston rod to press the semi-rigid beam, and the rigid beam is used to actuate the Gurney flap. Power is provided to the Gurney flap arrangement area, and the purpose of driving the Gurney flap is achieved by driving the connecting rod to rotate. The entire device adopts a negative feedback regulation mechanism, which is accurate and stable.

[0038] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A driving device based on hydraulic transmission and used for helicopter Gurney flap, characterized in that: The driving device is installed on the Gurney flap, and comprises: an electric push rod (1), an input end piston (2), a flexible conduit (3), a connecting rod (5) and a driving part; One end of the electric push rod (1) is a fixed end, and the fixed end is fixed to the hub of the helicopter Gurney flap, and the other end of the electric push rod (1) is connected to the input end piston (2); The input end piston (2) is connected to the driving part of the driving device through a flexible conduit (3), and the flexible conduit (3) is connected to the piston structure; The driving part is installed on the Gurney flap, wherein the driving part and the beam of the blade of the Gurney flap are staggered along the chord direction of the blade of the Gurney flap.

2. The driving device according to claim 1, characterized in that The driving part comprises: an output end piston (4), a rigid beam (6), a Gurney flap (7) and a mechanical device housing (8), wherein the mechanical device housing (8) is fixedly connected to the skin of the blade; One end of the output end piston (4) is connected to the flexible conduit (3), and the other end of the output end piston (4) is connected to the rigid beam (6) through a connecting rod (5). When the output end piston (4) moves, the rigid beam (6) is driven to move up and down through the connecting rod (5).

3. The driving device according to claim 1, characterized in that The driving part is installed at a distance of 75% of the radius between the blade and the hub, and the Gurney flap is arranged on the blade, wherein the Gurney flap is arranged at a distance of 80% to 90% of the chord length.

4. The driving device according to claim 1, characterized in that The electric push rod (1) is connected to the input end piston (2) and is connected to the output end piston (4) through a flexible conduit (3).

5. The device according to claim 1, characterized in that The flexible conduit (3) is connected to the piston structure and comprises: The portion of the flexible conduit (3) exposed outside the blade root is the extended side, and the extended side is sealedly connected to the input end piston (2) to form a piston-conduit connection; The portion of the flexible conduit (3) extending into the blade is the embedded side. The flexible conduit (3) is arranged along the radial direction of the blade and passes through the mechanical device housing (8) to be sealed and glued to the output end piston (4). The input-end piston (2) and the output-end piston (4) have the same internal structure, including a piston rod (9), a piston head (10) and a piston cylinder (11). The piston head (10) is installed on the top end of the piston rod (9); a piston ring is installed on the edge of the piston head (10), and the side of the piston ring is grooved. The piston rod (9) is installed in the piston cylinder (11), and the piston ring and the inner wall of the piston cylinder (11) cooperate with each other.

6. The device according to claim 1 or 5, characterized in that The two ends of the flexible conduit (3) are respectively glued to the top of the piston cylinder (11) of the input end piston (2) and the output end device (4); The portion of the flexible conduit (3) exposed outside the blade is the extended side of the flexible conduit, which is sealed and connected to the bottom of the corresponding piston cylinder (11) to form a piston-flexible conduit connection point.

7. The device according to claim 6, characterized in that The flexible conduit (3) extends into the blade at the trailing edge of the blade root, and the portion extending into the blade is the embedded side of the flexible conduit; A blind hole is opened on the mechanical device housing (8) so that the embedded side of the flexible conduit passes through the opened blind hole and is then sealed and glued to the output end piston (4) to form a piston-flexible conduit connection. The rigid beam (6) is fixedly connected to the Gurney flap (7) so that the rigid beam (6) drives the Gurney flap (7) to move up and down.

8. The device according to claim 5, characterized in that The cross section of the catheter at the piston-catheter connection adopts a smooth transition design to avoid leakage problems.

9. The device according to claim 1, characterized in that The electric push rod (1) and the input end piston (2) are both mounted on the propeller hub; Wherein, an actuator fixing device is pre-welded on the propeller hub, the shape of the mounting hole of the actuator fixing device matches the fixed end of the input end piston (2), and the fixed end of the input end piston (2) is tightly fitted with the mounting hole after being inserted into the mounting hole of the actuator fixing device; The actuator fixing device has holes so as to allow the flexible conduit (3) and the input end piston rod (2) to pass through respectively; A limit cover is installed on the edge of the mounting hole of the actuator fixing device by means of bolts, and the inner shape of the limit cover matches the cross section of the input end piston (2).

Images