Active vibration damping system of rotor system

Abstract

The invention discloses an active vibration reduction system of a rotor system, and belongs to the technical field of rotary machinery vibration reduction. The problems that an existing shock absorber cannot achieve self-adaptive shock absorption along with changes of shafting frequency, and universality is poor are solved. Comprising a circular ring type vibration reduction body used for being fixedly connected with a rotor shaft. Vibration reduction holes are evenly formed in the circumferential direction of the circular ring face of the vibration reduction body, and spring dampers are arranged in the vibration reduction holes. Mass blocks are evenly distributed on the outer edge of the surface of one side of the annular face of the damping body in the circumferential direction. The vibration damper is used for vibration damping of the rotor system.

Description

Technical Field

[0001] The invention relates to an active vibration reduction system for a rotor system, belonging to the technical field of vibration reduction of rotating machinery. Background Art

[0002] With the rapid iteration and development of aviation and aerospace technology, higher requirements are placed on the test equipment of transmission test benches for aviation products such as engines, transmission reducers and engine accessories.

[0003] Aviation rotor systems, such as the main rotor and tail rotor of helicopters, usually work under high-speed rotation conditions and are subject to extreme loads and environmental conditions. These conditions may cause vibrations in the rotor structure, affect flight safety and comfort, and even cause fatigue damage to components. Under these conditions, combined with the improvement of the test bench technical indicators, the complexity and diversity of the test functions, the series and parallel structure of the multi-stage rotor system, the materials, processing and installation of the rotors at each level, etc., it is bound to lead to uneven circumferential mass distribution of the rotor of the test bench system, causing the mechanical vibration of the rotor system to intensify. At the same time, with the complex and changeable characteristics of the test bench test conditions, the rotor system usually has to operate under extreme conditions such as high temperature, high pressure, and high speed, which puts higher requirements on the rotor performance, making the rotor vibration problem increasingly prominent, which puts higher requirements on the function of the vibration reduction device.

[0004] At present, common rotor vibration reduction technologies are usually divided into passive vibration absorption, active and semi-active vibration absorption. Passive vibration absorbers rely on pre-set parameters to absorb vibrations within a specific frequency range. This type of vibration absorber has poor flexibility and is difficult to adapt to changing working conditions. Passive vibration absorbers have high requirements for the constraint boundaries of shaft system simulation calculations, but the actual shaft system often has a large deviation between the shaft system test results and the simulation results due to a series of situations such as design deviations, processing errors, and installation. The critical speed obtained by simulation does not achieve a sufficient avoidance rate with the actual working conditions, resulting in coupled resonance (lateral vibration and torsional vibration) between the shaft system and the support structure, causing vibration to exceed the standard. Summary of the invention

[0005] In view of the problem that the existing vibration absorber cannot realize adaptive vibration absorption with the change of shaft system frequency and has poor versatility, the present invention provides an active vibration reduction system for a rotor system.

[0006] An active vibration reduction system for a rotor system of the present invention comprises a circular vibration reduction body for fixed connection with a rotor shaft; vibration reduction holes are evenly arranged along the circumference of the circular ring surface of the vibration reduction body, and spring dampers are arranged in the vibration reduction holes; and mass blocks are evenly arranged along the circumference of the outer edge of one side surface of the circular ring surface of the vibration reduction body.

[0007] According to the rotor active vibration reduction system of the present invention, the natural frequency of the vibration reduction system is made the same as the fixed frequency of the rotor system by adjusting the stiffness of the spring damper and the mass of the mass block, thereby absorbing the vibration energy of the rotor system.

[0008] According to the rotor active vibration reduction system of the present invention, the natural frequency of the vibration reduction system is adjusted according to the motion equation, and the motion equation is:

[0009]

[0010] Where M is the mass or moment of inertia of the main structure of the rotor system, x is the vibration displacement or angular displacement of the main structure of the rotor system, K is the stiffness of the main structure of the rotor system, c is the damping of the vibration reduction system, x1 is the vibration displacement or angular displacement of the vibration reduction system, k is the stiffness of the vibration reduction system, F is the external excitation, ω is the actual operating frequency of the main structure of the rotor system, t is the time; m is the mass or moment of inertia of the vibration reduction system.

[0011] According to the rotor active vibration reduction system of the present invention, the stiffness and mass of the vibration reduction system are adjusted according to the motion equation, so that the natural frequency of the vibration reduction system is the same as the natural frequency of the main structure of the rotor system; wherein the stiffness of the vibration reduction system is adjusted by adjusting the stiffness of the spring damper, and the mass or moment of inertia of the vibration reduction system is adjusted by adjusting the mass of the mass block.

[0012] According to the rotor active vibration reduction system of the present invention, three spring dampers are evenly arranged in each vibration reduction hole.

[0013] According to the rotor active vibration reduction system of the present invention, the vibration reduction body is sleeved on the rotor shaft via a flange.

[0014] Beneficial effects of the invention: The invention can be applied to active vibration reduction and noise reduction of the rotor shaft system of rotating machinery test benches in aviation, aerospace, etc. By actively changing the stiffness, damping, and mass of the vibration reduction body, the natural frequency of the structure body is changed to be consistent with the resonant frequency of the shaft system, thereby achieving active vibration absorption.

[0015] On the one hand, the system of the present invention can solve the problem of excessive vibration caused by resonance of the rotor near the test condition due to design calculation deviation, and actively absorb vibration, thereby controlling the problem of excessive vibration; on the other hand, it can be used to assist calibration when the rotor is bent and deformed.

[0016] The system of the present invention has a wide range of uses and can simultaneously solve the lateral vibration and torsional vibration problems of the rotor system, and can also achieve dynamic balance adjustment by adjusting the mass of the circumferential counterweight; the vibration reduction system absorbs vibration energy, which can extend the service life of the equipment and reduce the cost of maintenance and replacement; the rotor system is protected by vibration absorption, and the impact load on the rotor, bearings and structure is reduced, thereby improving the safety of the system; the system of the present invention has a simple structure and can adapt to a variety of load environment test conditions; it is easy to use and can be suitable for shaft systems of different sizes by replacing different flanges or bushing interfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the rotor active vibration reduction system of the present invention;

[0018] Figure 2 yes Figure 1 Side view of

[0019] Figure 3 It is a schematic diagram of the rotor active vibration reduction system sleeved on the rotor shaft;

[0020] Figure 4 It is the mathematical model diagram of the vibration reduction system;

[0021] Figure 5 It is a comparison diagram of the amplification factor of the vibration displacement of the main structure of the rotor system to the external excitation before and after the vibration reduction system is installed;

[0022] Figure 6 is a shaft system modeling diagram of the aviation test bench in the embodiment;

[0023] Figure 7 yes Figure 6 The simulation result of the shaft system is shown in the figure;

[0024] Figure 8 3 is a comparison diagram of the main structure amplitude of the rotor system of the aviation test bench before and after the vibration reduction system is installed in the embodiment; the upper half of the line corresponds to the state without the vibration reduction system, and the lower half of the line corresponds to the state with the vibration reduction system. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0028] Specific implementation method 1. Combination Figures 1 to 5 As shown, the present invention provides an active vibration reduction system for a rotor system, comprising a circular vibration reduction body 1, which is used to be fixedly connected to the rotor shaft; vibration reduction holes are evenly arranged along the circumferential direction of the circular surface of the vibration reduction body 1, and spring dampers 2 are arranged in the vibration reduction holes; and mass blocks 3 are evenly arranged along the circumferential direction on the outer edge of one side surface of the circular surface of the vibration reduction body 1.

[0029] Furthermore, by adjusting the stiffness of the spring damper 2 and the mass of the mass block 3, the natural frequency of the vibration reduction system is made the same as the fixed frequency of the rotor system, thereby absorbing the vibration energy of the rotor system.

[0030] In this embodiment, the natural frequency of the vibration reduction system is adjusted according to the motion equation, and the motion equation is:

[0031]

[0032] Where M is the mass or moment of inertia of the main structure of the rotor system, x is the vibration displacement or angular displacement of the main structure of the rotor system, K is the stiffness of the main structure of the rotor system, c is the damping of the vibration reduction system, x1 is the vibration displacement or angular displacement of the vibration reduction system, k is the stiffness of the vibration reduction system, F is the external excitation, ω is the actual operating frequency of the main structure of the rotor system, t is the time; m is the mass or moment of inertia of the vibration reduction system. The stiffness includes radial stiffness and torsional stiffness.

[0033] In actual use, the damping of the vibration reduction system is generally much greater than the damping of the main structure of the rotor system, so the damping of the main structure is usually ignored.

[0034] The stiffness and mass of the vibration reduction system are adjusted according to the motion equation so that the natural frequency of the vibration reduction system is the same as the natural frequency of the main structure of the rotor system; the stiffness of the vibration reduction system is adjusted by adjusting the stiffness of the spring damper 2, and the mass or moment of inertia of the vibration reduction system is adjusted by adjusting the mass of the mass block 3.

[0035] As an example, three spring dampers 2 are evenly arranged in each vibration-damping hole.

[0036] As an example, the vibration damping body 1 is sleeved on the rotor shaft via the flange 4 .

[0037] The number of mass blocks may be 12.

[0038] Working principle of the present invention: The present invention system simplifies the mathematical model as follows Figure 4As shown, the vibration reduction system is sleeved on the rotor shaft through the flange 4. The structural dimensions of the flange interface can be modified and designed according to the specific dimensions of the rotor. The vibration of the rotor system is directly transmitted to the vibration reduction system through the rotor shaft, which arouses the vibration of the vibration reduction body. By adjusting the stiffness of the vibration reduction body, the spring damper and the mass block, the total stiffness, damping and total mass of the vibration reduction system are changed, and then the natural frequency of the vibration reduction system itself is changed to achieve natural frequency adjustment.

[0039] According to the motion equation, the amplification factor A(g) of the vibration displacement or angular displacement x of the main structure of the rotor system to the external excitation can be calculated:

[0040]

[0041] Where g is the external load frequency ratio, g = ω / ω n , where ω n is the natural frequency of the main structure of the rotor system, ω n =(K / M) 0.5 , ε is the damping ratio of the vibration reduction system, ε=c / 2(mk) 0.5 ; f is the tuning ratio, f = ω1 / ω n , ω1 is the natural frequency of the vibration reduction system, ω1=(k / m) 0.5 ; μ is the mass ratio or moment of inertia ratio, μ = m / M.

[0042] Depend on Figure 5 It can be seen that after adding the vibration reduction system, the vibration energy of the rotor system is suppressed by the vibration reduction system, the energy is absorbed, and the amplitude is reduced.

[0043] Example: In view of the problem of excessive torque fluctuation on a certain aviation test bench, the torsional resonance of the shaft system was determined through simulation calculation and experimental test analysis. The vibration reduction system of the present invention was installed at the shaft flange connection after parameter adjustment. Figures 6 to 8 As shown, the problem of excessive torque fluctuation is solved.

[0044] In summary, the system of the present invention can achieve the best vibration reduction effect by adjusting parameters under different shaft system working conditions, and can effectively absorb the vibration of the rotor system.

[0045] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. An active vibration reduction system for a rotor system, characterized in that: It comprises a circular vibration-damping body (1) for fixed connection with a rotor shaft; vibration-damping holes are evenly arranged along the circumference of the circular ring surface of the vibration-damping body (1), and spring dampers (2) are arranged in the vibration-damping holes; and mass blocks (3) are evenly arranged along the circumference of the outer edge of one side surface of the circular ring surface of the vibration-damping body (1).

2. The rotor active vibration reduction system according to claim 1, characterized in that: By adjusting the stiffness of the spring damper (2) and the mass of the mass block (3), the natural frequency of the vibration reduction system is made the same as the fixed frequency of the rotor system, thereby absorbing the vibration energy of the rotor system.

3. The rotor active vibration reduction system according to claim 2, characterized in that: The natural frequency of the vibration reduction system is adjusted according to the motion equation, which is: Where M is the mass or moment of inertia of the main structure of the rotor system, x is the vibration displacement or angular displacement of the main structure of the rotor system, K is the stiffness of the main structure of the rotor system, c is the damping of the vibration reduction system, x1 is the vibration displacement or angular displacement of the vibration reduction system, k is the stiffness of the vibration reduction system, F is the external excitation, ω is the actual operating frequency of the main structure of the rotor system, t is the time; m is the mass or moment of inertia of the vibration reduction system.

4. The rotor active vibration reduction system according to claim 3, characterized in that: The stiffness and mass of the vibration reduction system are adjusted according to the motion equation so that the natural frequency of the vibration reduction system is the same as the natural frequency of the main structure of the rotor system; wherein the stiffness of the vibration reduction system is adjusted by adjusting the stiffness of the spring damper (2), and the mass or rotational inertia of the vibration reduction system is adjusted by adjusting the mass of the mass block (3).

5. The rotor active vibration reduction system according to claim 1, characterized in that: Three spring dampers (2) are evenly arranged in each vibration reduction hole.

6. The rotor active vibration reduction system according to claim 1, characterized in that: The vibration reduction body (1) is sleeved on the rotor shaft via a flange (4).

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