Collision experiment device for flexible rotor of squeeze film damper

Abstract

The invention discloses a collision experiment device for a flexible rotor of a squeeze film damper. The collision experiment device comprises a bottom plate, a long shaft, a motor, a disc, a first bearing seat, a first bearing, a second bearing seat, a second bearing, a first acceleration sensor, a second acceleration sensor, a first displacement sensor, a second displacement sensor, a rotating speed sensor and a data processing system. According to the invention, accurate simulation and effective data acquisition can be carried out on nonlinear resonance and self-excited oscillation of the rotor, so that the dynamic characteristics of the rotor system in practical application can be better simulated in practical application.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible rotor collision, and specifically relates to a squeeze film damper flexible rotor collision experimental device, which is particularly suitable for simulating and conducting data research on nonlinear resonance and self-excited oscillation phenomena when a bearing collides with a housing. Background Art

[0002] In mechanical equipment such as turbines and compressors with rotor-stator systems as the main structure, the rotor system may be affected by contact friction, mutual collision, material deformation and other factors in actual applications, causing the system to produce nonlinear resonance. Simulating the nonlinear resonance of the rotor can better understand the oscillation law of the rotor. There is a gap between the bearing seat and the housing in the squeeze film damper bearing. If the gap changes, the device will be unevenly stressed and the shaft will tilt, resulting in uneven load distribution and damage to the equipment, causing safety hazards and economic losses. Therefore, simulating the rotor collision will help to increase the understanding of rotor collision and reduce losses.

[0003] The Jeffcott rotor model can obtain the dynamic characteristics of the rotor and better study nonlinear resonance, but the model does not specifically consider the collision in the system when there is a radial gap. The invention with publication number CN218156802U discloses a multifunctional rotor test bench, which can simulate various rotor faults and has high practicality. The invention with publication number CN116625692B discloses a gear-type coaxial counter-rotating dual-rotor system simulation test bench. Through the designed and constructed test bench, the motion law of the coaxial counter-rotating dual-rotor system at the output end of the engine can be understood, the engine vibration signal can be monitored, and the unbalanced vibration of the dual-rotor system can be suppressed online. The invention with publication number CN114813141A discloses a multi-disc bolt-connected rotor rubbing test bench and its test method, which can widely consider the influence of the bolt preload, bolt tightening process, rubbing form, rubbing gap, rubbing stiffness, rubbing position and the combination of the above parameters on the inherent characteristics and dynamic characteristics of the entire rotor system. Other patents, such as CN114739651A, discloses a simulation device for loosening of aeroengine bearings with controllable end friction and radial clearance, and CN111999056B, discloses a multifunctional test bench for simulating vibration of helicopter tail transmission. None of these patents involve the collision problem in the system when there is radial clearance.

[0004] Therefore, a flexible rotor collision experimental model with a squeeze film damper is urgently needed, which can better simulate the dynamic characteristics of the rotor system in practical applications and provide a further understanding of the nonlinear resonance and self-excited oscillation of the rotor. Summary of the invention

[0005] Technical problem to be solved: The present invention provides a squeeze film damper flexible rotor collision test device, which can accurately simulate the nonlinear resonance and self-excited oscillation of the rotor and collect effective data, so as to better simulate the dynamic characteristics of the rotor system in actual applications.

[0006] Technical solution:

[0007] A squeeze film damper flexible rotor collision test device, the flexible rotor collision test device comprising a base plate, a long shaft, a motor, a disc, a first bearing seat, a first bearing, a second bearing seat, a second bearing, a first acceleration sensor, a second acceleration sensor, a first displacement sensor, a second displacement sensor, a speed sensor and a data processing system;

[0008] The base plate is fixed on the ground; the long axis is horizontally installed just above the base plate, the first bearing seat is installed in the middle of the long axis, and the second bearing seat is installed at the second end of the long axis; the first bearing seat and the second bearing seat are respectively connected to the base plate through the first bracket and the second bracket arranged vertically; the first bearing is installed in the first bearing seat; a shell is installed on the outer side of the second bearing seat, the second bearing and the second bearing seat are clearance-matched, and lubricating oil with a certain pressure is supplied to the clearance, and a bearing seat shell is attached to the outer side of the second bearing seat, and the bearing seat shell is responsible for transmitting the vibration of the second bearing and the second bearing seat;

[0009] The disc is fixed on the long axis, and the center of the disc and the axis of the long axis are on the same horizontal line;

[0010] The motor is mounted on the bottom plate through a fixing frame and supported by the bottom plate. The output end of the motor is connected to the first end of the long shaft through a coupling. The rotation speed of the output end is continuously increased according to an external control instruction to carry the long shaft to rotate until the long shaft undergoes nonlinear resonance and self-excited oscillation. The second bearing and the second bearing seat vibrate under the action of the gap oil film. The unbalanced force generated by the rotating shaft during movement causes the journal movement to squeeze the oil film ring between the bearing and the bearing seat to generate an oil film force. The oil film force has an adsorption effect on the bearing rotor to lift the bearing. At the same time, the vibration is reduced by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft, and a squeeze film damper is simulated.

[0011] The speed sensor is installed on the long shaft to collect the speed of the long shaft in real time;

[0012] The first acceleration sensor is fixed on the first bearing seat, and the second acceleration sensor is fixed on the second bearing seat, and the motion acceleration of the first bearing seat and the second bearing seat are recorded respectively;

[0013] The first displacement sensor is located between the first bracket and the disk, and is fixed to the bottom plate through a first fixing bracket; the second displacement sensor is located between the disk and the second bracket, and is fixed to the bottom plate through a second fixing bracket. The first displacement sensor and the second displacement sensor respectively measure the bending state of the long axis between the first bracket and the disk, and between the disk and the second bracket;

[0014] The data processing system is connected to the first acceleration sensor, the second acceleration sensor, the first displacement sensor, the second displacement sensor, and the speed sensor respectively; according to the bending states of the two sections of the long axis fed back by the first displacement sensor and the second displacement sensor, the vertical motion state of the bearing is plotted, so as to determine the eccentric displacement relationship between the position of the center of the long axis, that is, the center of the disk and the center position of the disk when the long axis is not rotating, and obtain different vibration modes of the rotating shaft when rotating; according to the actual speed of the rotating shaft recorded by the speed sensor, the angular velocity of the rotating shaft is obtained through mathematical relationships; according to the accelerations on the first bearing seat and the second bearing seat respectively measured by the first acceleration sensor and the second acceleration sensor, the displacement data of the bearing seat is obtained after secondary integration; finally, the motion trajectories of the disk and the outer ring of the bearing corresponding to different speeds when the long axis undergoes nonlinear resonance and self-excited oscillation are plotted.

[0015] Furthermore, the ratio of the distance from the disk to the first bearing to the distance from the disk to the second bearing is 11:7.

[0016] Furthermore, the flexible rotor collision test device also includes a disc cone sleeve, which is locked on the long shaft.

[0017] Furthermore, the first bearing and the second bearing both adopt double-layer ball bearings, and the positions of the balls are fixed by assembling retaining frames.

[0018] Furthermore, a horizontal key phase mark is arranged on the long axis, the key phase mark is parallel to a horizontal line where the axis of the long axis is located, and a rotation speed sensor is arranged at the position of the key phase mark.

[0019] Furthermore, the first acceleration sensor and the second acceleration sensor are fixed to the first bearing seat and the second bearing seat respectively by screws.

[0020] Furthermore, the diameter of the disc is 480 mm, the thickness is 5.5 mm, the diameter of the vertical elastic major axis is 16 mm, and the length is 900 mm.

[0021] Beneficial effects:

[0022] The squeeze film damper flexible rotor collision test device of the present invention can accurately simulate the nonlinear resonance and self-excited oscillation of the rotor and collect effective data, thereby better simulating the dynamic characteristics of the rotor system in actual applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a squeeze film damper flexible rotor collision test device of the present invention;

[0024] Figure 2 A cross-sectional view of a rotor assembly containing a gap. DETAILED DESCRIPTION

[0025] The following examples will enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0026] See also Figure 1 The present invention discloses a flexible rotor collision test device of a squeeze film damper, which comprises a base plate, a long shaft, a motor, a disc, a first bearing seat, a first bearing, a second bearing seat, a second bearing, a first acceleration sensor, a second acceleration sensor, a first displacement sensor, a second displacement sensor, a speed sensor and a data processing system.

[0027] The bottom plate is fixed on the ground; the long axis is horizontally installed just above the bottom plate, the first bearing seat is installed in the middle of the long axis, and the second bearing seat is installed at the second end of the long axis; the first bearing seat and the second bearing seat are connected to the bottom plate through the first bracket and the second bracket arranged vertically respectively; the first bearing and the second bearing are installed in the first bearing seat and the second bearing seat respectively, and the difference from the first bearing is that the outer side of the second bearing seat is installed with a shell, and the second bearing and the second bearing seat are clearance-matched, and lubricating oil with a certain pressure is supplied to the gap. The outer side of the second bearing seat is fitted with the bearing seat shell, and the shell is responsible for transmitting the vibration of the bearing and the bearing seat.

[0028] The disc is fixed on the long axis, and the center of the disc and the axis of the long axis are on the same horizontal line.

[0029] The motor is mounted on a base plate through a fixing frame and supported by the base plate. The output end of the motor is connected to the first end of the long shaft through a coupling. The rotation speed of the output end is continuously increased according to an external control instruction to carry the long shaft to rotate until the long shaft undergoes nonlinear resonance and self-excited oscillation. While the lubricating oil lifts the rotor in the gap, it suppresses the vibration of the long shaft by squeezing the oil film, thereby simulating a squeeze film damper. Specifically, when the self-rotation motion of the long shaft reaches a certain rotation speed, the second bearing and the second bearing seat vibrate under the action of the gap oil film, and the unbalanced force generated by the rotating shaft during the motion causes the journal motion to squeeze the oil film ring between the bearing and the bearing seat to generate an oil film force. The oil film force has a certain adsorption effect on the bearing rotor, lifts the bearing, and at the same time reduces vibration by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft. In the above motion, a squeeze film damper is simulated.

[0030] The rotation speed sensor is installed on the long shaft to collect the rotation speed of the long shaft in real time.

[0031] The first acceleration sensor is fixed on the first bearing seat, and the second acceleration sensor is fixed on the second bearing seat, and the movement acceleration of the first bearing seat and the second bearing seat are recorded respectively.

[0032] The first displacement sensor is located between the first bracket and the disk, and is fixed to the base plate by a first fixing frame; the second displacement sensor is located between the disk and the second bracket, and is fixed to the base plate by a second fixing frame; the first displacement sensor and the second displacement sensor respectively measure the bending state of the long axis between the first bracket and the disk, and between the disk and the second bracket, and then the data processing system calculates different vibration modes of the rotating shaft when it rotates.

[0033] The data processing system is connected to the first acceleration sensor, the second acceleration sensor, the first displacement sensor, the second displacement sensor, and the speed sensor respectively to obtain the corresponding collected data and draw the motion trajectories of the disk and the outer ring of the bearing corresponding to different speeds when the long axis undergoes nonlinear resonance and self-excited oscillation. Specifically, the first displacement sensor and the second displacement sensor respectively determine the bending state of the two sections of the long axis, and the data processing system can draw the vertical motion state of the bearing to determine the eccentric displacement relationship between the position of the center of the long axis, that is, the position of the center of the disk and the center position of the disk when the long axis is not rotating; the speed sensor records the actual speed of the rotating shaft, and the data processing system obtains the angular velocity of the rotating shaft through mathematical relationships; the first acceleration sensor and the second acceleration sensor respectively measure the acceleration on the first bearing seat and the second bearing seat, and the data processing system obtains the specific displacement of the bearing seat after the collected acceleration is double-integrated. Finally, the data processing system integrates all the information to draw the motion trajectories of the disk and the outer ring of the bearing corresponding to different speeds when the long axis undergoes nonlinear resonance and self-excited oscillation.

[0034] Motor 1 is a driving module. Motor 1 is adjusted to obtain different speeds. Motor 1 drives the elastic long shaft 6 to rotate through a coupling. A speed sensor 7 is installed on the elastic long shaft 6 to record the speed of the elastic long shaft in real time. The elastic long shaft drives the two bearings to rotate. At the same time, the elastic long shaft 6 bends during the rotation process. The displacement sensor 4 on the base records the motion state of the elastic long shaft 6. The first bearing on the left side drives the first bearing seat to vibrate during the rotation process. The motion state of the first bearing seat is recorded by the first acceleration sensor 3. The second bearing on the right side continuously collides with the housing during the rotation process. The vibration generated is transmitted to the second bearing seat. The motion state of the second bearing seat is also recorded by the second acceleration sensor 3.

[0035] The working principle of the flexible rotor collision test device simulating the squeeze film damper of the present invention is as follows: the motor is driven by the external control system to gradually accelerate the long shaft, and the bolt is screwed into the disc to fix it before acceleration. When a certain speed is reached, the system's own structure causes the shaft to have nonlinear resonance and self-excited oscillation, and the oil film force between the bearing and the bearing seat plays a vibration reduction role, suppressing the vibration of the shaft, and achieving the purpose of simulating the squeeze film damper. In the whole process, the displacement and vibration sensors measure the trajectory of the disc and the outer ring of the bearing, and the speed sensor measures the speed of the elastic long shaft. The above sensors collect data when the shaft starts to rotate, and all are connected to the data acquisition system for processing, so that the motion law of nonlinear resonance and self-excited oscillation can be obtained on the external computer. When the speed of the elastic shaft is accelerated, the actual situation of lubricating oil leakage is simulated, and the influence of the nonlinear resonance and self-excited vibration of the system under the condition of lubricating oil leakage can also be understood through the displacement and speed information.

[0036] like Figure 1 As shown, in this example, the diameter of the disc is 480 mm, the thickness is 5.5 mm, the diameter of the vertical elastic major axis is 16 mm, and the length is 900 mm. The ratio of the distance from the disc to the first bearing to the distance from the disc to the second bearing is 11:7.

[0037] In order to increase the system weight and strengthen the vibration, the flexible rotor collision test device also includes a disc cone sleeve, which is locked on the long shaft.

[0038] See also Figure 2 The first bearing and the second bearing both use double-layer ball bearings, and the ball positions are fixed by assembling retainers.

[0039] Regarding the installation method of each sensor, a horizontal key phase mark is set on the long axis, the key phase mark is parallel to the horizontal line where the axis of the long axis is located, and the speed sensor is set at the key phase mark position. The first acceleration sensor and the second acceleration sensor are respectively fixed to the first bearing seat and the second bearing seat by screws. The first displacement sensor and the second displacement sensor are respectively fixed to the bottom plate by the first fixing frame and the second fixing frame.

[0040] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A squeeze film damper flexible rotor collision test device, characterized in that: The flexible rotor collision test device comprises a base plate, a long shaft, a motor, a disc, a first bearing seat, a first bearing, a second bearing seat, a second bearing, a first acceleration sensor, a second acceleration sensor, a first displacement sensor, a second displacement sensor, a speed sensor and a data processing system; The base plate is fixed on the ground; the long axis is horizontally installed just above the base plate, the first bearing seat is installed in the middle of the long axis, and the second bearing seat is installed at the second end of the long axis; the first bearing seat and the second bearing seat are respectively connected to the base plate through the first bracket and the second bracket arranged vertically; the first bearing is installed in the first bearing seat; a shell is installed on the outer side of the second bearing seat, the second bearing and the second bearing seat are clearance-matched, and lubricating oil with a certain pressure is supplied to the clearance, and a bearing seat shell is attached to the outer side of the second bearing seat, and the bearing seat shell is responsible for transmitting the vibration of the second bearing and the second bearing seat; The disc is fixed on the long axis, and the center of the disc and the axis of the long axis are on the same horizontal line; The motor is mounted on the bottom plate through a fixing frame and supported by the bottom plate. The output end of the motor is connected to the first end of the long shaft through a coupling. The rotation speed of the output end is continuously increased according to an external control instruction to carry the long shaft to rotate until the long shaft undergoes nonlinear resonance and self-excited oscillation. The second bearing and the second bearing seat vibrate under the action of the gap oil film. The unbalanced force generated by the rotating shaft during movement causes the journal movement to squeeze the oil film ring between the bearing and the bearing seat to generate an oil film force. The oil film force has an adsorption effect on the bearing rotor to lift the bearing. At the same time, the vibration is reduced by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft, and a squeeze film damper is simulated. The speed sensor is installed on the long shaft to collect the speed of the long shaft in real time; The first acceleration sensor is fixed on the first bearing seat, and the second acceleration sensor is fixed on the second bearing seat, and the motion acceleration of the first bearing seat and the second bearing seat are recorded respectively; The first displacement sensor is located between the first bracket and the disk, and is fixed to the bottom plate through a first fixing bracket; the second displacement sensor is located between the disk and the second bracket, and is fixed to the bottom plate through a second fixing bracket. The first displacement sensor and the second displacement sensor respectively measure the bending state of the long axis between the first bracket and the disk, and between the disk and the second bracket; The data processing system is connected to the first acceleration sensor, the second acceleration sensor, the first displacement sensor, the second displacement sensor, and the speed sensor respectively; according to the bending states of the two sections of the long axis fed back by the first displacement sensor and the second displacement sensor, the vertical motion state of the bearing is plotted, so as to determine the eccentric displacement relationship between the position of the center of the long axis, that is, the center of the disk and the center position of the disk when the long axis is not rotating, and obtain different vibration modes of the rotating shaft when rotating; according to the actual speed of the rotating shaft recorded by the speed sensor, the angular velocity of the rotating shaft is obtained through mathematical relationships; according to the accelerations on the first bearing seat and the second bearing seat respectively measured by the first acceleration sensor and the second acceleration sensor, the displacement data of the bearing seat is obtained after secondary integration; finally, the motion trajectories of the disk and the outer ring of the bearing corresponding to different speeds when the long axis undergoes nonlinear resonance and self-excited oscillation are plotted.

2. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: The ratio of the distance from the disc to the first bearing to the distance from the disc to the second bearing is 11:

7.

3. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: The flexible rotor collision test device also includes a disc cone sleeve, which is locked on the long shaft.

4. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: The first bearing and the second bearing both adopt double-layer ball bearings, and the positions of the balls are fixed by assembling retaining frames.

5. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: A horizontal key phase mark is arranged on the long axis, the key phase mark is parallel to the horizontal line where the axis center of the long axis is located, and the rotation speed sensor is arranged at the position of the key phase mark.

6. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: The first acceleration sensor and the second acceleration sensor are fixed to the first bearing seat and the second bearing seat respectively by screws.

7. The squeeze film damper flexible rotor collision test device according to claim 1, characterized in that: The diameter of the disc is 480 mm and the thickness is 5.5 mm; the diameter of the vertical elastic major axis is 16 mm and the length is 900 mm.

Images