A flexible rotor collision experiment device of squeeze film damper

Abstract

The application discloses a flexible rotor collision experimental device of an extrusion oil film damper, which 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. The application can accurately simulate non-linear resonance and self-excited oscillation of a rotor and effectively collect data, so that the dynamic characteristics of a rotor system in actual application can be better simulated.

Description

Technical Field

[0001] This invention belongs to the technical field of flexible rotor collision, specifically relating to a flexible rotor collision experimental device with an extrusion oil film damper, which is particularly suitable for simulating and data researching nonlinear resonance and self-excited oscillation phenomena when a bearing collides with its housing. Background Technology

[0002] In mechanical equipment such as turbines and compressors, where the rotor-stator system is the main structure, the rotor system may experience nonlinear resonance phenomena due to factors such as contact friction, mutual collisions, and material deformation in practical applications. Simulating rotor nonlinear resonance phenomena can provide a better understanding of the rotor's oscillation patterns. In the bearing of a squeeze film damper, there is a gap between the bearing housing and the casing. Changes in this gap can cause uneven force distribution on the device, shaft tilting, and uneven load distribution, leading to equipment damage, safety hazards, and economic losses. Therefore, simulating rotor collisions helps to improve the understanding of rotor collisions and reduce losses.

[0003] The Jeffcott rotor model can obtain the dynamic characteristics of the rotor and better study nonlinear resonance, but this model does not specifically consider the collision in the system when there is radial clearance. Invention CN218156802U discloses a multifunctional rotor test bench capable of simulating various rotor faults, with high practicality. Invention 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 engine output end can be understood, engine vibration signals can be monitored, and unbalanced vibration of the dual-rotor system can be suppressed online. Invention CN114813141A discloses a multi-disc bolt-connected rotor rubbing test bench and its testing method, which can widely consider the influence of bolt preload, bolt tightening process, rubbing form, rubbing clearance, rubbing stiffness, rubbing position, and combinations of the above parameters on the inherent and dynamic characteristics of the entire rotor system. Other patents, such as CN114739651A which discloses a simulation device for simulating loosening of an aero-engine support with controllable end-face friction and radial clearance, and CN111999056B which discloses a multifunctional test bench for simulating vibration of a helicopter tail drive, do not address the collision problem in systems with radial clearance.

[0004] Therefore, there is an urgent need for a collision test model of a flexible rotor with an extrusion oil film damper, which can better simulate the dynamic characteristics of the rotor system in actual applications and provide a better understanding of the nonlinear resonance and self-excited oscillation of the rotor. Summary of the Invention

[0005] Technical problem solved: This invention provides a flexible rotor collision test device for an extrusion oil film damper, which can accurately simulate and effectively acquire data on the nonlinear resonance and self-excited oscillation of the rotor, thereby better simulating the dynamic characteristics of the rotor system in actual applications.

[0006] Technical solution:

[0007] A flexible rotor collision test device for an extrusion oil film damper, the flexible rotor collision test device includes a base plate, a long shaft, a motor, a disk, 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 to the ground; the long shaft is horizontally installed directly above the base plate, the first bearing seat is installed in the middle of the long shaft, and the second bearing seat is installed at the second end of the long shaft; the first bearing seat and the second bearing seat are respectively connected to the base plate by a vertically arranged first bracket and a second bracket; the first bearing is installed inside the first bearing seat; a housing is installed on the outside of the second bearing seat, the second bearing and the second bearing seat are in clearance fit, and lubricating oil with a certain pressure is supplied to the clearance; the bearing seat housing is attached to the outside of the second bearing seat, and the bearing seat housing is responsible for transmitting the vibration between the second bearing and the second bearing seat;

[0009] The disk is fixed on a long axis, and the center of the disk and the axis of the long axis are on the same horizontal line.

[0010] The motor is mounted on the base plate by a fixed 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. According to the external control command, the speed of the output end is continuously increased to carry the long shaft to rotate until the long shaft experiences 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 the movement causes the journal to move and squeeze the oil film ring between the bearing and the bearing seat to generate oil film force. This oil film force has an adsorption effect on the bearing rotor, lifting the bearing. At the same time, it reduces vibration by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft. The oil film damper is simulated.

[0011] The speed sensor is mounted 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 housing, and the second acceleration sensor is fixed on the second bearing housing, and the motion acceleration of the first bearing housing and the second bearing housing are recorded respectively;

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

[0014] The data processing system is connected to a first accelerometer, a second accelerometer, a first displacement sensor, a second displacement sensor, and a speed sensor, respectively. Based on the bending states of the two long shaft segments fed back by the first and second displacement sensors, the vertical motion state of the bearing is plotted, thereby determining the eccentric displacement relationship between the position of the long shaft center (i.e., the center of the disk) and the disk center position when the long shaft is not rotating, and obtaining different vibration modes of the rotating shaft during rotation. Based on the actual rotational speed of the rotating shaft recorded by the speed sensor, the angular velocity of the rotating shaft is obtained through mathematical relationships. Based on the accelerations on the first and second bearing seats measured by the first and second accelerometer sensors, respectively, the displacement data of the bearing seats is obtained after double integration. Finally, the motion trajectories of the disk and the outer ring of the bearing are plotted at different speeds when the long shaft undergoes nonlinear resonance and self-excited oscillation.

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

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

[0017] Furthermore, both the first and second bearings are double-layer ball bearings, with the ball positions fixed by an assembly cage.

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

[0019] Furthermore, the first accelerometer and the second accelerometer are fixed to the first bearing housing and the second bearing housing respectively by screws.

[0020] Furthermore, the disk has a diameter of 480 mm and a thickness of 5.5 mm; the vertical elastic major axis has a diameter of 16 mm and a length of 900 mm.

[0021] Beneficial effects:

[0022] The flexible rotor collision test device of the extrusion oil film damper of the present invention can accurately simulate and effectively collect data on the nonlinear resonance and self-excited oscillation of the rotor, thereby better simulating the dynamic characteristics of the rotor system in actual application. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the flexible rotor collision test device for the extrusion oil film damper of the present invention;

[0024] Figure 2 This is a cross-sectional view of a rotor assembly containing gaps. Detailed Implementation

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

[0026] See Figure 1 The present invention discloses a collision test device for a flexible rotor of an extrusion oil film damper. The flexible rotor collision test device includes a base plate, a long shaft, a motor, a disk, 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 base plate is fixed to the ground; the long shaft is horizontally installed directly above the base plate, with a first bearing housing installed in the middle of the long shaft and a second bearing housing installed at the second end of the long shaft; the first and second bearing housings are respectively connected to the base plate via vertically arranged first and second brackets; the first and second bearings are respectively installed inside the first and second bearing housings, respectively. Unlike the first bearing, the second bearing housing has a housing installed on its outer side, and there is a clearance fit between the second bearing and the second bearing housing, with pressurized lubricating oil supplied to the clearance. The bearing housing housing is attached to the outside of the second bearing housing, and the housing is responsible for transmitting the vibration between the bearing and the bearing housing.

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

[0029] The motor is mounted on the base plate via a mounting bracket and supported by the base plate. The output end of the motor is connected to the first end of the long shaft via a coupling. According to external control commands, the speed of the output end is continuously increased to drive the long shaft to rotate until the long shaft experiences nonlinear resonance and self-excited oscillation. The lubricating oil in the gap supports the rotor while suppressing the vibration of the long shaft by squeezing the oil film. The squeezing oil film damper is simulated. Specifically, when 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. The unbalanced force generated by the shaft during the movement causes the journal to squeeze the oil film ring between the bearing and the bearing seat, generating an oil film force. This oil film force has a certain adsorption effect on the bearing rotor, lifting the bearing. At the same time, it reduces vibration by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft. The squeezing oil film damper is simulated in the above movement.

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

[0031] The first accelerometer is fixed on the first bearing housing, and the second accelerometer is fixed on the second bearing housing, and the motion acceleration of the first bearing housing and the second bearing housing are recorded respectively.

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

[0033] The data processing system is connected to a first accelerometer, a second accelerometer, a first displacement sensor, a second displacement sensor, and a speed sensor, respectively, to acquire corresponding data and plot the motion trajectories of the disk and bearing outer ring at different rotational speeds when the long shaft undergoes nonlinear resonance and self-excited oscillation. Specifically, the first and second displacement sensors determine the bending state of the two segments of the long shaft, and the data processing system can plot the vertical motion state of the bearing to determine the eccentric displacement relationship between the position of the long shaft center (i.e., the disk center) and the disk center position when the long shaft is not rotating. The speed sensor records the actual rotational speed of the shaft, and the data processing system obtains the angular velocity of the shaft through mathematical relationships. The first and second accelerometers measure the acceleration on the first and second bearing seats, respectively, and the data processing system obtains the specific displacement of the bearing seats by integrating the acquired acceleration twice. Finally, the data processing system integrates all the information to plot the motion trajectories of the disk and bearing outer ring at different rotational speeds when the long shaft undergoes nonlinear resonance and self-excited oscillation.

[0034] Motor 1 serves as the drive module. Adjusting motor 1 yields different speeds. Motor 1 drives the flexible long shaft 6 to rotate via a coupling. A speed sensor 7 is mounted on the flexible long shaft 6 to record its speed in real time. The flexible long shaft drives two bearings to rotate. Simultaneously, the flexible long shaft 6 bends during rotation, and a displacement sensor 4 on the base records its motion state. During rotation, the first bearing on the left causes the first bearing seat to vibrate, and the motion state of the first bearing seat is recorded by a first acceleration sensor 3. During rotation, the second bearing on the right continuously collides with the outer casing, and the resulting vibration is transmitted to the second bearing seat, where the motion state is also recorded by a second acceleration sensor 3.

[0035] The working principle of the flexible rotor collision experimental device of this invention, simulating the working principle of a squeeze oil film damper, is as follows: An external control system drives a motor to gradually accelerate the long shaft. Before acceleration, bolts are screwed into the disc for fixation. When a certain speed is reached, the system's own structure causes the shaft to undergo nonlinear resonance and self-excited oscillation. The oil film force between the bearing and the bearing seat then acts as a damping agent, suppressing shaft vibration and simultaneously simulating the squeeze oil film damper. Throughout the process, displacement and vibration sensors measure the trajectories of the disc and the outer ring of the bearing, while a velocity sensor measures the rotational speed of the elastic long shaft. These sensors collect data when the shaft begins to rotate. All data is connected to a data acquisition system and processed, allowing the motion laws of nonlinear resonance and self-excited oscillation to be obtained on an external computer. Simultaneously, as the elastic shaft speed increases, the actual situation of lubricating oil leakage is simulated. Displacement and velocity information can also be used to understand the impact of lubricating oil leakage on the system's nonlinear resonance and self-excited vibration.

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

[0037] To increase the system's counterweight and enhance vibration, the flexible rotor collision test device also includes a disc cone sleeve, which is locked onto the long shaft.

[0038] See Figure 2 Both the first and second bearings are double-layer ball bearings, and the ball positions are fixed by assembling cages.

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

[0040] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A collision test apparatus for a flexible rotor with an extrusion oil film damper, characterized in that, The flexible rotor collision test device includes a base plate, a long shaft, a motor, a disk, a first bearing housing, a first bearing, a second bearing housing, 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 to the ground; the long shaft is horizontally installed directly above the base plate, the first bearing seat is installed in the middle of the long shaft, and the second bearing seat is installed at the second end of the long shaft; the first bearing seat and the second bearing seat are respectively connected to the base plate by a vertically arranged first bracket and a second bracket; the first bearing is installed inside the first bearing seat; a housing is installed on the outside of the second bearing seat, the second bearing and the second bearing seat are in clearance fit, and lubricating oil with a certain pressure is supplied to the clearance; the bearing seat housing is attached to the outside of the second bearing seat, and the bearing seat housing is responsible for transmitting the vibration between the second bearing and the second bearing seat; The disk is fixed on a long axis, and the center of the disk and the axis of the long axis are on the same horizontal line. The motor is mounted on the base plate by a fixed 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. According to the external control command, the speed of the output end is continuously increased to carry the long shaft to rotate until the long shaft experiences 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 the movement causes the journal to move and squeeze the oil film ring between the bearing and the bearing seat to generate oil film force. This oil film force has an adsorption effect on the bearing rotor, lifting the bearing. At the same time, it reduces vibration by squeezing and shearing the oil film, so that the oil film suppresses the vibration of the long shaft. The oil film damper is simulated. The speed sensor is mounted 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 housing, and the second acceleration sensor is fixed on the second bearing housing, and the motion acceleration of the first bearing housing and the second bearing housing are recorded respectively; The first displacement sensor is located between the first support and the disk, and is fixed to the base plate by the first fixing bracket; the second displacement sensor is located between the disk and the second support, and is fixed to the base plate by the second fixing bracket. The first displacement sensor and the second displacement sensor respectively measure the bending state of the long axis between the first support and the disk, and between the disk and the second support. The data processing system is connected to a first accelerometer, a second accelerometer, a first displacement sensor, a second displacement sensor, and a speed sensor, respectively. Based on the bending states of the two long shaft segments fed back by the first and second displacement sensors, the vertical motion state of the bearing is plotted, thereby determining the eccentric displacement relationship between the position of the long shaft center (i.e., the center of the disk) and the disk center position when the long shaft is not rotating, and obtaining different vibration modes of the rotating shaft during rotation. Based on the actual rotational speed of the rotating shaft recorded by the speed sensor, the angular velocity of the rotating shaft is obtained through mathematical relationships. Based on the accelerations on the first and second bearing seats measured by the first and second accelerometer sensors, respectively, the displacement data of the bearing seats is obtained after double integration. Finally, the motion trajectories of the disk and the outer ring of the bearing are plotted at different speeds when the long shaft undergoes nonlinear resonance and self-excited oscillation.

2. The flexible rotor collision test apparatus for the extrusion oil film damper according to claim 1, characterized in that, The ratio of the distance from the disk to the first bearing to the distance to the second bearing is 11:

7.

3. The flexible rotor collision test apparatus for the extrusion oil film damper according to claim 1, characterized in that, The flexible rotor collision test device also includes a disc cone sleeve, which is locked onto the long shaft.

4. The flexible rotor collision test apparatus for the extrusion oil film damper according to claim 1, characterized in that, Both the first and second bearings are double-layer ball bearings, and the ball positions are fixed by mounting cages.

5. The flexible rotor collision test apparatus for the extrusion oil film damper according to claim 1, characterized in that, A horizontal key phase mark is provided on the long shaft, and the key phase mark is parallel to the horizontal line where the axis of the long shaft is located. The speed sensor is set at the key phase mark position.

6. The collision test apparatus for the extrusion oil film damper flexible rotor according to claim 1, characterized in that, The first accelerometer and the second accelerometer are fixed to the first bearing housing and the second bearing housing respectively by screws.

7. The flexible rotor collision test apparatus for the extrusion oil film damper according to claim 1, characterized in that, The disk has a diameter of 480mm and a thickness of 5.5mm; the vertical elastic long axis has a diameter of 16mm and a length of 900mm.

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