Combined type nonlinear damping device of helicopter main speed reducer
By designing a combined nonlinear vibration reduction device of the helicopter main reducer, using the nonlinear vibration absorption mechanism and vibration isolation counterweight, the problem of wideband vibration reduction of the helicopter is solved, and effective control of the rotor vibration load is achieved, adapting to speed changes, and ensuring that The safety and efficiency of the helicopter.
Patent Information
- Application Number
- CN202411192158.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2024-12-06
AI Technical Summary
Existing helicopter vibration damping technology is difficult to meet the wideband vibration damping requirements, especially in new variable speed high-speed helicopters, rotor speed changes lead to a larger vibration load frequency bandwidth, and traditional vibration damping technology is difficult to effectively control.
A combined nonlinear vibration absorption device of the main reducer of the helicopter is designed, including a support rod, a vibration absorption lever, a base, a mounting groove, a spring support, a vibration isolation counterweight and a nonlinear vibration absorption mechanism, and the vibration isolation configuration is adjusted. Heavy block mass, position, vibration absorption counterweight block mass and spring stiffness achieve wide band vibration damping effect. The nonlinear vibration absorption mechanism uses the damping force and friction force of the rubber damping roller and spring to consume vibration energy, combining vibration isolation and vibration absorption functions.
It realizes effective reduction of the vibration load transmitted by the helicopter rotor through the main reducer, adapts to the frequency of excitation force caused by the change of speed, has wide-band vibration damping characteristics, is simple in structure, convenient in installation and maintenance, and is cheap in cost, ensuring the helicopter's Safety and productivity.
Smart Images
Figure CN119084529A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of vibration control, and in particular relates to a combined nonlinear vibration reduction device for a main reducer of a helicopter. Background Art
[0002] Helicopters will generate continuous and changing vibration loads during missions. The crew and onboard equipment are in a harsh vibration environment for a long time, which seriously affects their work efficiency and easily leads to flight risks. With the development of rotor technology and the emergence of new configuration helicopters, the frequency bandwidth of the vibration load on the aircraft becomes larger due to the variable rotor speed, because of the two working states of low-speed maneuvering and high-speed cruising. The vibration control frequency of the commonly used vibration reduction technology is often relatively fixed, which is difficult to meet the requirements of wide-band vibration reduction. Summary of the invention
[0003] The purpose of the present invention is to provide a combined nonlinear vibration reduction device between a helicopter main reducer and a platform, so as to reduce the vibration load transmitted from the helicopter rotor to the fuselage through the main transmission channel such as the main reducer.
[0004] Technical solution: A combined nonlinear vibration reduction device for a helicopter main reducer, the device comprising a strut 1, a vibration reduction lever 2, a base 3, a mounting slot 4, a spring support 5, a vibration isolation counterweight 6 and a nonlinear vibration absorption mechanism 7, the nonlinear vibration absorption mechanism 7 comprising a rubber damping roller 71, a spring 72 and a vibration absorption counterweight 73, wherein:
[0005] The upper end of the strut 1 is hinged to the upper end of the main reducer, and the strut 1 rotates around the hinge point during the up and down movement of the main reducer, and the lower end of the strut 1 is hinged to the damping lever 2; one end of the damping lever 2 is hinged to the base 3, and the base 3 is fixed on the platform. The damping lever 2 rotates around the hinge point of the base 3 under the action of the axial force of the strut 1, and the other end of the damping lever 2 is provided with a nonlinear vibration absorbing mechanism 7; the middle part of the damping lever 2 is provided with a mounting groove 4, and the spring support 5 is fixed in the mounting groove 4. The position of the spring support 5 is adjusted accordingly according to the design requirements. The spring support 5 will be affected by a pre-pressure in the initial state and produce compression deformation. During the rotation of the damping strut 2, the spring support 5 will cause elastic deformation. Due to the existence of the spring damping force, the spring support 5 plays a role in vibration reduction and energy consumption; the vibration isolation counterweight 6 is fixed in the middle mounting groove, so as to achieve vibration isolation effects at different frequencies; the nonlinear vibration absorbing mechanism 7 is a diamond frame structure on the outside, which is arranged at one end of the damping lever 2.
[0006] Specifically, the weight of the vibration isolation counterweight 6 is 0.1% of the total weight of the designed helicopter.
[0007] Specifically, the weight of the vibration absorbing counterweight 73 is 0.2% of the total weight of the designed helicopter.
[0008] Specifically, the vibration absorbing counterweight 73 is a rectangular parallelepiped structure, with hanging ears arranged on both sides, and is suspended in the spring mounting holes in the nonlinear vibration absorbing mechanism 7 through two springs 72 .
[0009] Specifically, the spring 72 is in a stretched state in an initial state.
[0010] Specifically, the rubber damping roller 71 includes a metal roller and a damping material. The rubber damping roller 71 is installed in a roller installation hole in the hollow part of the diamond frame structure of the nonlinear vibration absorbing mechanism 7, and both ends of the rubber damping roller 71 have limit pins for installation and fixation in the hollow part of the nonlinear vibration absorbing mechanism 7. The metal roller surface of the rubber damping roller 71 is vulcanized with a rubber material with high damping properties.
[0011] Specifically, two rubber damping rollers 71 are arranged on each side of the vibration absorbing counterweight 73, contacting and rolling relative to the vibration absorbing counterweight 73. The two side surfaces of the vibration absorbing counterweight 73 that contact the rubber damping roller 71 are polished to make the surface rough, and the friction force during the rolling process is increased, thereby utilizing the damping force and friction force of the rubber damping roller 71 to dissipate vibration energy.
[0012] Specifically, the installation position of the rubber damping roller 71 will limit the vibration absorbing counterweight 73 to only vertical movement inside the diamond frame structure of the nonlinear vibration absorbing mechanism 7. During the vertical movement, the vibration absorbing counterweight 73 will pull the spring 72 to perform nonlinear movement and generate nonlinear stiffness. The spring 72 and the vibration absorbing counterweight 73 form a nonlinear vibration absorbing system.
[0013] The advantages of the present invention are:
[0014] Compared with the helicopter main reduction vibration control device in the prior art, the helicopter main reducer combined nonlinear vibration reduction device can adjust the vibration isolation frequency range of the structure by adjusting the mass of the vibration isolation counterweight, the position of the vibration isolation counterweight, and the position of the spring support. The vibration absorption capacity and vibration reduction frequency range of the structure can be adjusted by adjusting the mass of the vibration absorption counterweight and the spring. It takes into account the performance characteristics of vibration isolation and vibration absorption, has wide-band vibration reduction characteristics, and can adjust component parameters in a targeted manner to meet actual vibration reduction requirements, effectively reducing the vibration load transmitted by the helicopter through the main reducer, and can adapt to the changes in the exciting force frequency caused by changes in the helicopter speed. It has a simple structure, is easy to install and maintain, has high stability, and is low in cost, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 A schematic diagram of a combined nonlinear vibration reduction device for a helicopter main reducer provided in the present application;
[0016] Figure 2 A schematic diagram of the installation relationship of the vibration reduction lever 2 of the combined nonlinear vibration reduction device for the main reducer of the helicopter provided in this application;
[0017] Figure 3 A partial diagram of the nonlinear vibration absorbing mechanism provided for this application;
[0018] Among them: 1-support rod, 2-vibration reduction lever 2, 3-base, 4-installation slot, 5-spring support, 6-vibration isolation counterweight, 7-nonlinear vibration absorption mechanism, 71-rubber damping roller, 72-spring, 73-vibration absorption counterweight. DETAILED DESCRIPTION
[0019] The helicopter rotor is subjected to alternating aerodynamic loads containing harmonic components of integer multiples of the rotor speed, forming alternating forces and moments at the blade root. These forces and moments are combined to form a hub excitation load with a frequency of kNΩ (k is an integer), which is transmitted to the fuselage through the main reduction structure, causing the fuselage to vibrate. In view of the transmission characteristics of the helicopter rotor excitation force, the excitation load can be isolated from the helicopter fuselage by installing an elastic device to reduce the vibration level of the helicopter.
[0020] Compared with traditional linear dampers, nonlinear dampers have lower peak frequency and response, wider damping bandwidth, and no loss of static load-bearing capacity. Taking full advantage of this feature, a vibration reduction system with high static and low dynamic stiffness can be designed. Therefore, developing a new nonlinear vibration reduction system and guiding the vibration reduction design of variable speed rotor helicopters is an important process in the development of new high-speed helicopters.
[0021] The present invention is a combined nonlinear vibration reduction device for a helicopter main reducer, which is a vibration control structure that takes both vibration isolation and vibration absorption into consideration. The installation position of the vibration isolation mass block, the mass of the vibration absorption counterweight block and the stiffness of the suspension spring can be adjusted according to the actual situation of the vibration control target, so as to achieve the best vibration control effect while meeting the actual working conditions.
[0022] like Figure 1 As shown, the present application provides a combined nonlinear vibration reduction device for use between a helicopter main reducer and a platform, comprising a strut 1, a vibration reduction lever 2, a base 3, a mounting slot 4, a spring support 5, a vibration isolation counterweight 6 and a nonlinear vibration absorption mechanism 7, wherein the nonlinear vibration absorption mechanism 7 comprises a rubber damping roller 71, a spring 72 and a vibration absorption counterweight 73, wherein:
[0023] The upper end of the support rod 1 is hinged to the upper end of the main reducer by bolts, and the support rod 1 rotates around the hinge point during the up and down movement of the main reducer. The lower end of the support rod 1 is hinged to the damping lever 2 by bolts; one end of the damping lever 2 is hinged to the base 3, and the base 3 is fixed to the platform by bolts. The damping lever 2 rotates around the hinge point of the base 3 under the axial force of the support rod 1, and the other end of the damping lever 2 is provided with a nonlinear vibration absorbing mechanism 7; the middle part of the damping lever 2 is provided with a mounting groove 4, and the spring support 5 is fixed to the mounting groove 4 by bolts. In the mounting groove 4, the position of the spring support 5 is adjusted accordingly according to the design requirements. The spring support 5 will be compressed and deformed under the influence of a pre-pressure in the initial state. During the rotation of the vibration-damping strut 2, the spring support 5 will be elastically deformed. Due to the existence of the spring damping force, the spring support 5 plays a role in vibration reduction and energy consumption; the vibration isolation counterweight block 6 is fixed in the middle mounting groove by bolts, so as to achieve vibration isolation effects at different frequencies; the nonlinear vibration absorption mechanism 7 has a diamond frame structure on the outside and is arranged at one end of the vibration-damping lever 2.
[0024] Specifically, the weight of the vibration isolation counterweight 6 is 0.1% of the total weight of the designed helicopter.
[0025] Specifically, the weight of the vibration absorbing counterweight 73 is 0.2% of the total weight of the designed helicopter.
[0026] Specifically, the vibration absorbing counterweight 73 is a rectangular parallelepiped structure, with hanging ears arranged on both sides, and is suspended in the spring mounting holes in the nonlinear vibration absorbing mechanism 7 through two springs 72 .
[0027] Specifically, the spring 72 is in a stretched state in an initial state.
[0028] Specifically, the rubber damping roller 71 includes a metal roller and a damping material. The rubber damping roller 71 is installed in a roller installation hole in the hollow part of the diamond frame structure of the nonlinear vibration absorbing mechanism 7, and both ends of the rubber damping roller 71 have limit pins for installation and fixation in the hollow part of the nonlinear vibration absorbing mechanism 7. The metal roller surface of the rubber damping roller 71 is vulcanized with a rubber material with high damping properties.
[0029] Specifically, two rubber damping rollers 71 are arranged on each side of the vibration absorbing counterweight 73, contacting and rolling relative to the vibration absorbing counterweight 73. The two side surfaces of the vibration absorbing counterweight 73 that contact the rubber damping roller 71 are polished to make the surface rough, and the friction force during the rolling process is increased, thereby utilizing the damping force and friction force of the rubber damping roller 71 to dissipate vibration energy.
[0030] Specifically, the installation position of the rubber damping roller 71 will limit the vibration absorbing counterweight 73 to only vertical movement inside the diamond frame structure of the nonlinear vibration absorbing mechanism 7. During the vertical movement, the vibration absorbing counterweight 73 will pull the spring 72 to perform nonlinear movement and generate nonlinear stiffness. The spring 72 and the vibration absorbing counterweight 73 form a nonlinear vibration absorbing system.
[0031] It should be noted that the stiffness of this nonlinear system will change due to the deformation of the spring 72, and it is a change in cubic stiffness, so this nonlinear system has no natural frequency and can achieve wide-band vibration absorption of helicopter vibrations. This nonlinear characteristic will cause the vibration energy transmitted from the strut 1 to be transmitted to the vibration absorbing counterweight 73, and most of the vibration energy will no longer be transmitted back to the strut 1 or the fuselage, but will be consumed by the movement of the vibration absorbing counterweight 73 and the damping of the spring 72.
[0032] The key points of the present invention are:
[0033] Compared with the traditional main vibration reduction and isolation system, this dual-frequency adjustable helicopter main vibration reduction and isolation device has a two-stage vibration reduction mechanism, which comprehensively utilizes the primary vibration reduction mechanism and the secondary vibration reduction mechanism to reduce the vibration level caused by different external excitation frequencies of the variable speed helicopter. The rubber spring component not only provides the elastic force for the reciprocating rotation of the vibration reduction lever, but also provides the damping force to consume the vibration energy during the movement. The vibration reduction lever is hinged to the base and fixed to the platform. In the event of failure of the primary and secondary vibration reduction mechanisms, it can still meet the vertical load requirements of the system and ensure the safety of the helicopter during flight.
[0034] One of the features of the dual-frequency adjustable helicopter main vibration isolation device is that the position of the vibration reduction mass block is adjustable, and the connection position between the spring plate and the primary mass block is adjustable. This design makes the vibration isolation frequency of the primary and secondary vibration reduction systems adjustable, reducing the impact of the vibration reduction effect caused by installation errors and design deviations.
[0035] Another feature of the dual-frequency adjustable helicopter main reduction vibration isolation device is the design of the anti-twist system. The anti-twist system, which consists of an anti-twist connection plate and rubber anti-twist parts, releases the vertical freedom of the bottom of the main reducer. At the same time, the rubber anti-twist parts can provide a certain damping consumption of the main reducer's motion energy when the main reducer makes vertical reciprocating motion. The rubber anti-twist parts are designed to be flat and wide, which can effectively prevent the main reducer from rotating around the central axis and consume rotational energy. When the first and second vibration reduction mechanisms of the vibration reduction lever 2 fail, the system can provide partial vertical support and vibration reduction, thereby improving the safety of the main reduction system.
[0036] The working principle of the present invention is as follows:
[0037] When the main reducer connected to the main rotor of the helicopter vibrates under the action of external load, the axial vibration motion of the main reducer will be converted into axial motion of the strut.
[0038] After installing the helicopter main reducer combined nonlinear vibration reduction device, the axial movement of the strut acts on the vibration reduction lever 2, driving the vibration reduction lever 2 to reciprocate around the base hinge point, and the vibration reduction lever 2 and the vibration isolation counterweight block and nonlinear vibration absorption mechanism connected thereto rotate together. At the same time, under the action of the restoring force of the spring support, the vibration reduction lever 2 system forms a force to restore to the original state. The nonlinear vibration absorption mechanism set at the end of the vibration reduction lever 2 produces a movement deviating from the original position under the action of the lever rotation, so that the vibration absorption counterweight block reciprocates up and down in the original position under the action of the spring suspension on both sides and the rubber damping roller limit, and the vibration energy is dissipated by the damping force and friction force of the rubber damping roller. Thus, the vibration absorption effect is achieved.
[0039] The advantages of the present invention are:
[0040] Compared with the helicopter main reduction vibration control device in the prior art, the helicopter main reducer combined nonlinear vibration reduction device can adjust the vibration isolation frequency range of the structure by adjusting the mass of the vibration isolation counterweight, the position of the vibration isolation counterweight, and the position of the spring support. The vibration absorption capacity and vibration reduction frequency range of the structure can be adjusted by adjusting the mass of the vibration absorption counterweight and the spring. It takes into account the performance characteristics of vibration isolation and vibration absorption, has wide-band vibration reduction characteristics, and can adjust component parameters in a targeted manner to meet actual vibration reduction requirements, effectively reducing the vibration load transmitted by the helicopter through the main reducer, and can adapt to the changes in the exciting force frequency caused by changes in the helicopter speed. It has a simple structure, is easy to install and maintain, has high stability, and is low in cost, saving costs.
[0041] In summary, the combined nonlinear vibration reduction device for the main reducer of a helicopter provided in the present application is used as a vibration control device between the main reducer and the mounting platform, and realizes the vibration suppression effect of the helicopter transmitted to the fuselage through the main reducer in a wide frequency range. The device described in the present invention comprehensively utilizes a vibration isolation mechanism and a vibration absorption mechanism, including a strut, a vibration reduction lever 2, a base, a spring support, a vibration isolation counterweight and a nonlinear vibration absorption mechanism. The upper and lower ends of the strut are respectively hinged to the main reducer and the vibration reduction lever 2. The vibration reduction lever 2 is hinged to the base and fixed to the mounting platform through a spring support. The rubber damping roller in the nonlinear vibration absorption mechanism at the end of the vibration reduction lever 2 provides a damping force that consumes the vibration energy of the counterweight. The present invention is mainly used to reduce the vibration level of the fuselage caused by various external excitation frequencies of the helicopter rotor, and in the event of failure of the vibration reduction mechanism, it can still meet the requirements of the vertical load of the system and ensure the flight safety of the helicopter.
Claims
1. A helicopter main reducer combined nonlinear vibration reduction device, characterized in that: The device comprises a support rod (1), a vibration reduction lever (2), a base (3), a mounting groove (4), a spring support (5), a vibration isolation counterweight (6) and a nonlinear vibration absorption mechanism (7), wherein the nonlinear vibration absorption mechanism (7) comprises a rubber damping roller (71), a spring (72) and a vibration absorption counterweight (73), wherein: The upper end of the support rod (1) is hinged to the upper end of the main reducer, and the support rod (1) rotates around the hinge point during the process of the main reducer moving up and down. The lower end of the support rod (1) is hinged to the damping lever (2); one end of the damping lever (2) is hinged to the base (3), and the base (3) is fixed on the platform. The damping lever (2) rotates around the hinge point of the base (3) under the action of the axial force of the support rod (1), and the other end of the damping lever (2) is provided with a nonlinear vibration absorbing mechanism (7); the middle part of the damping lever (2) is provided with a mounting groove (4), and the spring support (5) is fixed on the mounting groove. The position of the spring support (5) is adjusted in accordance with design requirements in the mounting groove (4). The spring support (5) is subjected to a pre-pressure in the initial state and generates compression deformation. During the rotation of the vibration-damping strut (2), the spring support (5) generates elastic deformation. Due to the existence of the spring damping force, the spring support (5) plays a role in vibration reduction and energy consumption. The vibration isolation counterweight (6) is fixed in the middle mounting groove, thereby achieving vibration isolation effects at different frequencies. The nonlinear vibration absorption mechanism (7) is externally a diamond frame structure and is arranged at one end of the vibration-damping lever (2).
2. The device according to claim 1, characterized in that The weight of the vibration isolation counterweight (6) is 0.1% of the total weight of the designed helicopter.
3. The device according to claim 1, characterized in that The weight of the vibration absorbing counterweight (73) is 0.2% of the total weight of the designed helicopter.
4. The device according to claim 1, characterized in that The vibration absorbing counterweight (73) is a rectangular parallelepiped structure, with hanging ears arranged on both sides, and is suspended in a spring mounting hole in the nonlinear vibration absorbing mechanism (7) through two springs (72).
5. The device according to claim 1, characterized in that The spring (72) is in a stretched state in an initial state.
6. The device according to claim 1, characterized in that The rubber damping roller (71) comprises a metal roller and a damping material. The rubber damping roller (71) is installed in a roller installation hole in a hollow part of a diamond frame structure of a nonlinear vibration absorbing mechanism (7). Both ends of the rubber damping roller (71) are provided with limit pins for installation and fixation in the hollow part of the nonlinear vibration absorbing mechanism (7). The metal roller surface of the rubber damping roller (71) is vulcanized with a rubber material having high damping properties.
7. The device according to claim 1, characterized in that Two rubber damping rollers (71) are arranged on each side of the vibration absorbing counterweight (73), and are in contact with the vibration absorbing counterweight (73) and roll relative to the counterweight (73). The two side surfaces of the vibration absorbing counterweight (73) in contact with the rubber damping rollers (71) are polished to make the surfaces rough, thereby increasing the friction force during the rolling process, and then utilizing the damping force and friction force of the rubber damping rollers (71) to dissipate vibration energy.
8. The device according to claim 1, characterized in that The installation position of the rubber damping roller (71) will restrict the vibration absorbing counterweight (73) to only perform vertical movement inside the diamond frame structure of the nonlinear vibration absorbing mechanism (7). During the vertical movement, the vibration absorbing counterweight (73) will pull the spring (72) to perform nonlinear movement and generate nonlinear stiffness. The spring (72) and the vibration absorbing counterweight (73) form a nonlinear vibration absorbing system.