Helicopter rotor blade based on seamless trailing edge flap mechanism

Abstract

The present invention discloses a helicopter rotor blade based on a seamless trailing edge flap mechanism, comprising a blade body and a plurality of trailing edge flap modules; the trailing edge flap module comprises a housing, a driver, a push-pull rod, a drive rod, a mounting platform, a first flexible hinge, a second flexible hinge, a trailing edge flap and a sealing sheet. The driver generates a dynamic linear displacement output; the driver, the push-pull rod, the drive rod and the trailing edge flap are sequentially connected, and the force and displacement output generated by the driver are transmitted to the trailing edge flap; the trailing edge flap is connected to the mounting platform through a second flexible hinge, and the linear reciprocating motion of the push-pull rod is converted into a trailing edge flap deflection motion through the second flexible hinge. The present invention is used for the active control of the helicopter trailing edge flap rotor, and the aerodynamic load distribution of the blade is dynamically changed through the dynamic deflection of the trailing edge flap, the vibration load of the helicopter rotor is suppressed, or the rotor noise is suppressed through the method of sound field cancellation.

Description

Technical Field

[0001] The invention relates to the field of active control of helicopter rotor vibration and noise, and in particular to a helicopter rotor blade based on a seamless trailing edge flap mechanism. Background Art

[0002] Compared with other types of aircraft, helicopters have the characteristics of vertical take-off and landing and efficient hovering, and have been widely used in civil and military fields. However, during the use of helicopters, the vibration and noise problems have always been prominent, which has had a negative impact on the further development of helicopters. When the helicopter is in forward flight, the rotor is in an asymmetric and complex working environment. The shock wave of the forward blade, the dynamic stall of the backward blade, and the reversal zone cause the rotor to produce strong vibration and noise. Strong vibration and noise problems not only affect the comfort of helicopter drivers and passengers, but also have an adverse effect on the structural life of the helicopter and the reliability of the onboard equipment. Therefore, how to reduce the vibration and noise levels of the helicopter has always been a hot topic in helicopter research.

[0003] The rotor is one of the main sources of helicopter vibration and noise, so it is necessary to take suppression measures on the rotor to suppress helicopter vibration and noise from the source. The helicopter rotor control technology applied to the rotor can be mainly divided into two categories: passive and active vibration control technology. Among them, passive vibration control technology, such as dual-line swing force absorber and offline swing absorber, has been applied in many types of active helicopters, significantly reducing helicopter vibration. Although passive rotor vibration control technology has good vibration control effect, it also has shortcomings such as large additional structural mass and narrow operating frequency range. Therefore, active vibration control technology came into being. According to the different installation positions of the actuator, the active vibration control technology applied to the helicopter rotor can be divided into: high-order harmonic control technology with the actuator acting on the fixed ring of the automatic tilt device, independent blade control technology with the actuator located in the pitch rod, active torsion rotor with the actuator distributed on the rotor blade, and intelligent rotor with the trailing edge flap where the actuator is located inside the blade. For high-order harmonic control technology and independent blade control technology, since their actuators are connected in series with the helicopter control system, actuator failure may endanger the flight safety of the helicopter. The active torsion rotor actuator is attached to the inside of the blade and is independent of the helicopter control system. It has high safety, but there are problems such as drive and delamination. At the same time, in order to increase the active torsion amplitude of the rotor, the blade structural characteristics need to be adjusted, which is not conducive to the dynamic stability of the blade. Compared with other forms of active rotor vibration control technology, the trailing edge flap intelligent rotor has a simple structure, less impact on the blade structure, and no direct connection with the helicopter control system. It has high safety and has more engineering application potential under current technical conditions.

[0004] The trailing edge flap needs to deflect relative to the blade body. The existing trailing edge flap design mostly adopts the traditional hinge mechanism. There will inevitably be a chord-wise gap between the trailing edge flap and the blade body. The airflow flowing through the upper and lower surfaces of the blade will pass through the chord-wise gap, reducing the aerodynamic efficiency of the trailing edge flap. In addition, in the existing trailing edge flap design, the trailing edge flap and the drive mechanism are separately connected to the blade body, and the inspection and maintenance of the mechanism are achieved through the cover set on the upper or lower surface of the blade. On the one hand, the existence of the cover changes the aerodynamic shape of the blade. On the other hand, due to the high ground clearance of the blade, the trailing edge flap and the drive mechanism directly mounted and fixed to the blade body bring inconvenience to daily inspection and maintenance work. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a helicopter rotor blade based on a seamless trailing edge flap mechanism in view of the defects involved in the background technology.

[0006] The present invention adopts the following technical solutions to solve the above technical problems

[0007] A helicopter rotor blade based on a seamless trailing edge flap mechanism, comprising a blade body and a plurality of trailing edge flap modules;

[0008] The trailing edge flap module comprises a shell, a driver, a push-pull rod, a driving rod, a mounting platform, a first flexible hinge, a second flexible hinge, a trailing edge flap and a sealing sheet;

[0009] The shell is a hollow body with one end closed and the other end open; one end of the mounting platform is fixedly connected to the open end of the shell, and a through hole is provided between the two ends of the mounting platform for the driving rod to pass through;

[0010] The driver is fixed in the housing, and its output end is fixedly connected to one end of the push-pull rod;

[0011] One end of the driving rod is fixedly connected to the other end of the push-pull rod, and the other end passes through the mounting platform and is connected to the head of the trailing edge flap via the first flexible hinge, so as to transmit the driving force and displacement of the driver to the trailing edge flap;

[0012] One end of the upper surface of the trailing edge flap close to the mounting platform is bonded to the upper surface of the mounting platform through a second flexible hinge, so that the trailing edge flap can perform deflection movement around the second flexible hinge; the second flexible hinge cooperates with the first flexible hinge to convert the linear motion of the driving rod into the deflection motion of the trailing edge flap;

[0013] An end of the mounting platform away from the housing is provided with a mounting groove below the through hole thereof that matches the sealing sheet;

[0014] One end of the sealing sheet is bonded to one end of the lower surface of the trailing edge flap close to the mounting platform, and the other end is inserted into the mounting groove on the mounting platform, and can slide in the mounting groove in cooperation with the first flexible hinge and the second flexible hinge, so as to keep the lower surface of the airfoil smooth and prevent airflow from passing through the upper and lower surfaces of the blade;

[0015] The blade body is provided with a plurality of slots corresponding to the trailing edge flap modules one by one;

[0016] The trailing edge flap module is arranged in its corresponding slot, and the shell of the trailing edge flap module is detachably connected to the blade body. When the helicopter rotor blade rotates, the centrifugal load generated by the trailing edge flap module is transmitted to the blade body through the shell.

[0017] As a further optimization scheme of the helicopter rotor blade based on the seamless trailing edge flap mechanism of the present invention, the push-pull rod comprises two metal parts with U-shaped cross-sections, and the openings of the two metal parts are facing each other and fixedly connected to each other to form a hollow cylinder.

[0018] As a further optimization solution of the helicopter rotor blade based on the seamless trailing edge flap mechanism of the present invention, the metal component with a U-shaped cross-section is formed by bending a high-strength lightweight alloy plate.

[0019] As a further optimization solution for the helicopter rotor blade based on the seamless trailing edge flap mechanism of the present invention, a plurality of through holes are provided on the upper and lower surfaces of the shell to reduce its structural weight.

[0020] The first flexible hinge, the driving rod and the trailing edge flap are all made of composite materials and are integrally formed during processing, which effectively reduces the number of fasteners and reduces the weight of the entire structure. The housing has a driver mounting opening on the side, through which the driver is placed in the housing, and after being aligned with the countersunk hole on the housing, the driver is fixed to the housing using screws.

[0021] The working principle of the present invention is:

[0022] Driven by an electrical signal, the driver generates a linear displacement output, which is transmitted to the trailing edge flap through the push-pull rod, the drive rod and the first flexible hinge, driving the trailing edge flap to deflect around the second flexible hinge; a sealing sheet is installed on the trailing edge flap, one end of the sealing sheet is bonded to the sealing sheet mounting platform on the lower surface of the trailing edge flap, and the other end is inserted into the mounting groove of the mounting platform, so as to keep the lower surface of the blade smooth and seal the lower surface of the blade; the trailing edge flap module is inserted into the slot of the blade body and fixed with bolts, and the centrifugal load generated by the driver and other components is finally transmitted to the blade body through the casing.

[0023] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0024] The present invention integrates the trailing edge flap and its driving mechanism into a relatively independent module. After the mechanism adjustment and overhaul and maintenance are completed on the workbench, the module can be inserted as a whole into the slot in the blade body, which can significantly reduce the system maintenance workload and improve the engineering practical value of the trailing edge flap. After the trailing edge flap module is inserted into the slot in the blade body, it fits tightly with the blade body without a chord-wise gap, and there is no need to set an inspection cover on the upper and lower surfaces of the blade body, thereby ensuring that the upper and lower surfaces of the blade are smooth and improving the aerodynamic efficiency of the trailing edge flap. The trailing edge flap is connected to the mounting platform by a flexible hinge. The flexible hinge made of a composite material sheet not only ensures the aerodynamic shape of the upper surface of the blade, but also does not require additional lubrication measures, thereby improving the maintainability of the trailing edge flap while improving the aerodynamic efficiency of the trailing edge flap. A sealing sheet is installed between the lower surface of the trailing edge flap and the mounting platform to seal the lower surface of the blade to prevent airflow leakage on the upper and lower surfaces of the blade, thereby further improving the aerodynamic efficiency of the trailing edge flap. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present invention;

[0026] Figure 2 is a schematic structural diagram of a trailing edge flap module in the present invention;

[0027] Figure 3 is a cross-sectional view of a trailing edge flap module in the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the trailing edge flap and the driving rod in the present invention;

[0029] Figure 5 It is a schematic structural diagram of a U-shaped cross-section metal component of the push-pull rod in the present invention;

[0030] Figure 6 It is a schematic diagram of the structure of the shell and the mounting platform in the present invention;

[0031] Figure 7 It is a cross-sectional view of the present invention.

[0032] In the figure, 1-blade body, 2-trailing edge flap module, 3-shell, 4-through hole on the upper surface of the shell, 5-second flexible hinge, 6-trailing edge flap, 7-sealing sheet, 8-driver, 9-push-pull rod, 10-driving rod, 11-mounting platform, 12-first flexible hinge, 13-mounting groove. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0034] The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0035] The invention discloses a helicopter rotor blade based on a seamless trailing edge flap mechanism, comprising a blade body and a plurality of trailing edge flap modules;

[0036] like Figure 2 , Figure 3 As shown, the trailing edge flap module includes a shell, a driver, a push-pull rod, a driving rod, a mounting platform, a first flexible hinge, a second flexible hinge, a trailing edge flap and a sealing sheet;

[0037] like Figure 6 As shown, the shell is a hollow body with one end closed and the other end open; one end of the mounting platform is fixedly connected to the open end of the shell, and a through hole for the driving rod to pass through is provided between the two ends of the mounting platform;

[0038] The driver is fixed in the housing, and its output end is fixedly connected to one end of the push-pull rod;

[0039] One end of the driving rod is fixedly connected to the other end of the push-pull rod, and the other end passes through the mounting platform and is connected to the head of the trailing edge flap through the first flexible hinge, so as to transmit the driving force and displacement of the driver to the trailing edge flap. Figure 4 As shown;

[0040] One end of the upper surface of the trailing edge flap close to the mounting platform is bonded to the upper surface of the mounting platform through a second flexible hinge, so that the trailing edge flap can perform deflection movement around the second flexible hinge; the second flexible hinge cooperates with the first flexible hinge to convert the linear motion of the driving rod into the deflection motion of the trailing edge flap;

[0041] An end of the mounting platform away from the housing is provided with a mounting groove below the through hole thereof that matches the sealing sheet;

[0042] One end of the sealing sheet is bonded to one end of the lower surface of the trailing edge flap close to the mounting platform, and the other end is inserted into the mounting groove on the mounting platform, and can slide in the mounting groove in cooperation with the first flexible hinge and the second flexible hinge, so as to keep the lower surface of the airfoil smooth and prevent airflow from passing through the upper and lower surfaces of the blade;

[0043] like Figure 1As shown, the blade body is provided with a plurality of slots corresponding to the trailing edge flap modules one by one; the trailing edge flap modules are arranged in the corresponding slots, and the shell of the trailing edge flap module is detachably connected to the blade body. When the helicopter rotor blade rotates, the centrifugal load generated by the trailing edge flap module is transmitted to the blade body through the shell. Figure 7 shown.

[0044] like Figure 5 As shown, the push-pull rod comprises two U-shaped metal parts, the openings of the two metal parts are facing each other and fixedly connected to each other to form a hollow cylinder; the U-shaped metal part is formed by bending a high-strength lightweight alloy plate, which effectively reduces its structural weight and processing cost while ensuring the rigidity of the push-pull rod.

[0045] The upper and lower surfaces of the shell are provided with a plurality of through holes to reduce the weight of the structure and facilitate maintenance of the drive mechanism. The first flexible hinge, the drive rod and the trailing edge flap are all made of composite materials and are integrally formed during processing, which effectively reduces the number of fasteners and reduces the weight of the entire structure. The side of the shell has a driver installation port, through which the driver is placed in the shell, and after being aligned with the countersunk hole on the shell, the driver is fixed to the shell with screws.

[0046] Through the above structural design, the present invention solves the following problems:

[0047] 1) When the trailing edge flap intelligent rotor is working, the trailing edge flap needs to perform a small dynamic deflection relative to the blade body to generate additional aerodynamic load to suppress rotor vibration or noise;

[0048] 2) In the conventional trailing edge flap mechanism design, the trailing edge flap and the drive mechanism are separately installed and fixed to the blade body. The inspection and maintenance of the trailing edge flap mechanism can only be completed through the maintenance cover on the upper or lower surface of the blade, which increases the workload of the trailing edge flap mechanism maintenance. In addition, the maintenance cover on the blade surface will also affect the integrity of the blade's aerodynamic shape, thereby affecting the aerodynamic efficiency of the trailing edge flap.

[0049] 3) In the conventional trailing edge flap mechanism design, mechanical hinges are used between the trailing edge flap and the blade body. These mechanical hinges need to be lubricated with grease or lubricating oil. When the blade rotates, the grease or lubricating oil is easily thrown out, resulting in lubrication failure;

[0050] 4) The chord-wise clearance between the trailing edge flap and the blade body will cause airflow to penetrate the upper and lower surfaces of the blade, reducing the aerodynamic efficiency of the trailing edge flap.

[0051] 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 generally 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 common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0052] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A helicopter rotor blade based on a seamless trailing edge flap mechanism, characterized in that: It includes a blade body and a number of trailing edge flap modules; The trailing edge flap module comprises a shell, a driver, a push-pull rod, a driving rod, a mounting platform, a first flexible hinge, a second flexible hinge, a trailing edge flap and a sealing sheet; The shell is a hollow body with one end closed and the other end open; one end of the mounting platform is fixedly connected to the open end of the shell, and a through hole is provided between the two ends of the mounting platform for the driving rod to pass through; The driver is fixed in the housing, and its output end is fixedly connected to one end of the push-pull rod; One end of the driving rod is fixedly connected to the other end of the push-pull rod, and the other end passes through the mounting platform and is connected to the head of the trailing edge flap via the first flexible hinge, so as to transmit the driving force and displacement of the driver to the trailing edge flap; One end of the upper surface of the trailing edge flap close to the mounting platform is bonded to the upper surface of the mounting platform through a second flexible hinge, so that the trailing edge flap can perform deflection movement around the second flexible hinge; the second flexible hinge cooperates with the first flexible hinge to convert the linear motion of the driving rod into the deflection motion of the trailing edge flap; An end of the mounting platform away from the housing is provided with a mounting groove below the through hole thereof that matches the sealing sheet; One end of the sealing sheet is bonded to one end of the lower surface of the trailing edge flap close to the mounting platform, and the other end is inserted into the mounting groove on the mounting platform, and can slide in the mounting groove in cooperation with the first flexible hinge and the second flexible hinge, so as to keep the lower surface of the airfoil smooth and prevent airflow from passing through the upper and lower surfaces of the blade; The blade body is provided with a plurality of slots corresponding to the trailing edge flap modules one by one; The trailing edge flap module is arranged in its corresponding slot, and the shell of the trailing edge flap module is detachably connected to the blade body. When the helicopter rotor blade rotates, the centrifugal load generated by the trailing edge flap module is transmitted to the blade body through the shell.

2. The helicopter rotor blade based on the seamless trailing edge flap mechanism according to claim 1, characterized in that: The push-pull rod comprises two metal parts with U-shaped cross-sections, and the two metal parts have openings facing each other and are fixedly connected to each other to form a hollow cylinder.

3. The helicopter rotor blade based on the seamless trailing edge flap mechanism according to claim 2, characterized in that: The metal component with the U-shaped cross section is formed by bending a high-strength light alloy plate.

4. The helicopter rotor blade based on the seamless trailing edge flap mechanism according to claim 1, characterized in that: The upper and lower surfaces of the shell are both provided with a plurality of through holes for reducing the structural weight thereof.

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