CN1657800A - A method and device for suppressing vibration of a rotor system with elastic support - Google Patents

Abstract

The invention is a method for preventing rotator system variation with flexible support and its device, aiming at solving the problems of high accuracy requirement and hard technique, by the relative movement of movable friction disc and still friction disc in dry friction damper to create frictional force, bring outer damping into the rotator system to decreased its variation in critical rotational speed, so that its stability is improved. The concrete method includes: mount movable friction disc and still friction disc onto axial, through pressure carried by force applicating and adjusting the pressure to change the damper value. After bringing into dry friction damper, the variation of rotator in critical rotational speed as well as its vibration can be prevented effectively; it has simple structure.

Description

A method and device for suppressing vibration of a rotor system with elastic support

(1) Technical field:

The invention relates to the mechanical field, and relates to a method and a device for suppressing vibration of a rotor system with elastic support.

(2) Technical background:

With the rapid development of modern industrial technology, a large number of rotor systems adopt flexible rotor design. Since the elastic support can reduce the critical speed of the rotor and has a certain support and damping effect, it has been widely used in flexible rotors, especially in the field of aerodynamic engineering. Most modern aeroengines use flexible rotors with elastic support structures. design. However, the use of an elastic support structure also brings corresponding problems. When the rotor passes the critical speed, the elastic support will have a large deformation. The problem is transformed into the deformation and strength of the supporting structure. Therefore, it is very necessary to introduce external damping in the system to reduce the vibration of the rotor system. At present, the commonly used methods of introducing damping include squeeze oil film damper, metal rubber damper, etc., but these methods have certain defects to varying degrees. . For example, the squeeze oil film damper widely used in the field of practical engineering has the advantages of good vibration reduction effect, but if the design and manufacture are not good or the imbalance of the rotor deteriorates, the nonlinearity of the oil film force will be greatly increased, resulting in many harmful nonlinear Linear response.

Dry friction damping has been widely used as a means of vibration reduction, and plays an important role in engineering fields such as railway and highway suspension systems and seismic foundation isolation of high-rise buildings. In recent years, using dry friction damping to reduce the vibration of aeroengine blades has become a high-tech that has attracted much attention and has been studied in depth, and has been applied to the design of new aeroengines. However, no one has so far combined the problem of dry friction damping with rotor system vibration damping.

(3) Contents of the invention:

In order to overcome the deficiencies of high precision requirement and difficult process in the prior art, the present invention proposes a method for introducing dry friction damping to suppress the vibration of the rotor system with elastic support.

The technical solution adopted by the present invention is to generate friction force through the relative motion between the dynamic and static friction plates in the dry friction damper, and introduce external damping into the rotor system to reduce the vibration of the rotor system when passing the critical speed and improve the performance of the rotor system. Stability of operation.

The dry friction damper proposed by the present invention mainly includes a dynamic friction plate, a static friction plate and a force applying device. The dynamic friction plate is set on the shaft and fixedly connected with the elastic support; the bearing is fixed in the inner hole of the dynamic friction plate; the static friction plate is located on one side of the dynamic friction plate and can move in the axial direction, and is applied to the dynamic friction plate by a force device The pressure is kept in contact, and the pressure is adjusted through the force device to achieve the purpose of adjusting the damping value.

The working method of the present invention is: when the rotor is stationary, the elastic support is also in a static state, and there is no relative displacement between the friction plates, so no friction occurs; The relative displacement creates dry friction between the two friction plates, which provides damping for the rotor system, thereby reducing the vibration of the rotor system when it passes the critical speed.

The technical solution adopted in the present invention is to propose an effective suppression method for the vibration problem of the rotor system with elastic support. After the introduction of dry friction damping, the vibration of the rotor when it passes the critical speed will be effectively suppressed, and it can also prevent the rotor from destabilizing vibration. Compared with existing technologies such as squeeze film dampers, the introduction of dry friction damping has the advantages of simple structure, easy control of applied damping, and less external influence. At the same time, this method can also be used in combination with other methods, and because the damping effect is easy to control, it has broad application prospects in the field of active control.

(4) Description of drawings:

Accompanying drawing 1 utilizes spring to apply the dry friction damper device structural diagram of force;

Accompanying drawing 2 is a schematic diagram of the structure of a dry friction damper;

Attached Figure 3.1 The damping effect after applying dry friction damping (comparison of the amplitude-frequency characteristic curve of the acceleration)

Attached Figure 3.2 The vibration reduction effect after applying dry friction damping (comparison of the amplitude-frequency characteristic curve of speed reduction)

in:

1. Coupling 2. Support 3. Elastic support 4. Dynamic friction plate

5. Bearing 6. Static friction plate 7. Fixed support 8. Spring leading rod

9. Spring 10. Shaft 11. Spring rear guide rod 12. Pressure plate

13. Spring barrel 14. Disk

(5) Specific implementation methods:

In this embodiment, external damping caused by dry friction is introduced into the rotor system to reduce the vibration of the rotor system when passing a critical speed and improve the stability of the rotor system.

In this embodiment, according to the structure of the rotor system, a corresponding dry friction damper is designed, and a widely used squirrel-cage elastic support structure is adopted to establish a dry friction damper with a spring as force. In this embodiment, the relative motion between the dynamic and static friction plates in the dry friction damper is used to generate friction to provide external damping to the rotor system. The working method is that when the rotor does not vibrate, the elastic support is in a static state, and the If there is no relative displacement, there will be no friction; when the rotor vibrates, relative displacement will occur between the dynamic friction plate and the static friction plate on the elastic support end surface, and dry friction will be generated between the two friction plates to provide damping for the rotor system, thereby reducing the rotor system. Vibration when passing a critical speed.

This embodiment mainly includes a flexible rotor system, a dynamic friction plate 4 , a static friction plate 6 , an elastic support 3 and a force applying device ( FIG. 1 ). The force applying device adopts a spring as a force applying method.

Flexible rotor system: mainly includes elastic support 3 , bearing 5 , shaft 10 and disk 14 . The elastic support 3 adopts a squirrel-cage elastic support and is fixed on the support 2 by bolts. The bearing 5 is fixed in the moving friction plate 4 through a tight fit.

The dynamic friction plate 4 is sleeved on the shaft 10 , and one end surface is fixedly connected with the elastic support 3 ; the bearing 5 is fixed in the inner hole of the dynamic friction plate 4 . The static friction plate 6 is sleeved on the shaft 10, located on the other end surface of the dynamic friction plate 4, and installed in the hole of the fixed support 7. The two are slidingly fitted in the axial direction, and the force applying device can be passed between the two and the dynamic friction plate 4. The applied pressure is kept in contact, and the pressure is adjusted by the force applying device to achieve the purpose of adjusting the damping value.

Force applying device: it is made up of spring front guide rod 8, spring rear guide rod 11, spring 9, pressing plate 12, spring barrel 13. The spring tube 13 is set on the shaft 10, fixed on the support 7 by bolts, independent of the rotor system; the spring 9, the front guide rod 8 and the rear guide rod 11 are respectively installed in the tube: the two guide rods 8, 11 are set on the shaft 10, located at both ends of the spring 9, its function is to make the spring 9 deform uniformly in the axial direction, and the pressing force generated can be vertically and uniformly loaded on the static friction plate 6. The inner wall of the spring barrel 13 is threaded, and the pressure plate 12 cooperates with the spring barrel 13 through the thread. When the position of the pressure plate 12 in the spring barrel 13 is adjusted, the spring 9 can be compressed to obtain the expected pressing force, which provides a pressing force for the static friction plate 6. force to keep the contact between the dynamic and static friction plates.

In this embodiment, the dimensional data of the dry friction damper and the rotor system are as follows: the disk radius is 120mm, the thickness is 40mm, the shaft length (distance between two bearing midpoints) is 715mm, and the shaft radius is 14mm. The actual measured stiffness coefficient of the squirrel cage elastic support is 5.7167×10 ⁵ N/m. The elastic coefficient of the spring is determined to be 17.64N/mm by experiments. The material of the dynamic and static friction plates is A3 steel, and the friction coefficient is 0.15.

Figure 3.1 and Figure 3.2 are the amplitude-frequency characteristic curves of the measured speed-up and deceleration when the rotor speed is increased from 500rpm to 3600rpm and then decreased to 500rpm under different pressing forces. where positive pressure is shown as a parameter. The results in the figure show that the elastically supported dry friction damper has an obvious damping effect in the critical speed region no matter in the process of speed up or deceleration. When the pressing force is 370N, the vibration amplitude is reduced from 510 μm without dry friction damping to about 100 μm, and the vibration reduction effect is very obvious.

Claims (2)

1. the method for an inhibition zone yielding support vibration of rotor system, it is characterized in that producing frictional force by the relative movement between the dynamic and static friction plate in the dry damping device, in rotor-support-foundation system, introduce external damping, to reduce the vibration of rotor-support-foundation system the time by critical speed of rotation.

2. device of realizing the described inhibition zone yielding support of claim 1 vibration of rotor system, it is characterized in that this device mainly comprises movable friction plate (4), static friction sheet (6) and force application device, wherein movable friction plate (4) is sleeved on the axle (10), fixedlys connected with yielding support (3); Bearing (5) is fixed in the endoporus of movable friction plate (4); Static friction sheet (6) is positioned at movable friction plate (4) one sides, can move vertically, and and movable friction plate (4) between keep in touch by force application device institute applied pressure.

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