Backup bearing device for suppressing rotor-stator contact fault and test method

Abstract

The invention discloses a backup bearing device for inhibiting a rotor-stator contact fault and a test method.The backup bearing device comprises a suspension cross beam and a mounting enclosure frame, a motor is mounted on the suspension cross beam, a disc and an annular guide rail frame are movably arranged on the inner side of the mounting enclosure frame, and the disc is coaxially connected to the inner side of the annular guide rail frame in a sleeving mode; and the disc is movably matched with the annular guide rail frame. According to the invention, the traditional'continuous surface constraint 'is changed into'discrete point limit', so that the full-annular contact of the rotor and the stator is fundamentally avoided, two harmful motion modes of'reverse vortex motion 'or'continuous forward vortex motion' are thoroughly eliminated, and the reverse vortex motion or the continuous forward vortex motion caused by the full-annular continuous contact is avoided. In a dry or lubricating state, the device can effectively maintain the rotating speed of the rotor to be stable, and transverse vibration is remarkably restrained. The device is ingenious in structure, flexible in adjustment and capable of effectively improving the operation safety and prolonging the service life of equipment.

Description

Technical Field

[0001] This invention relates to the fields of rotating machinery dynamics and bearing protection technology, specifically to a backup bearing device and test method for suppressing rotor-stator contact failures. Background Technology

[0002] In high-speed rotating machinery, the rubbing between the rotor and stator is one of the key faults leading to severe vibration and catastrophic failure. The traditional mainstream protection solution is to install a continuous, complete annular guide sleeve around the rotor as a backup bearing. However, this design principle based on a continuous constraint interface has a fundamental flaw: Firstly, under dry friction conditions, the continuous circumferential contact between the rotor and the inner wall of the guide sleeve will induce strong Coulomb damping, which will cause the rotational kinetic energy to be dissipated rapidly, the rotor speed to drop sharply or even "lock up", and at the same time induce the rotor center to carry out reverse vortex with continuously increasing amplitude, forming a vicious cycle of "deceleration-impact". Secondly, even under lubrication, although the friction is reduced, the rotor is very likely to fall into a "full-circular positive vortex" state that keeps in continuous contact with the inner wall of the guide sleeve, and cannot break away from the contact on its own. Long-term operation will lead to directional wear and temperature rise.

[0003] Existing research is mostly based on the ideal driving assumption of constant rotor angular velocity, which fails to solve the "non-ideal driving" problem in actual engineering where the motor drive characteristics (torque-speed curve) are strongly coupled with the rotor's lateral dynamics. The crux of the problem is that the axisymmetric continuous constraint of the traditional annular guide sleeve cannot provide the rotor with an asymmetric restoring force to break the harmful whirl mode and guide it back to the center.

[0004] Therefore, there is an urgent need for a backup bearing structure that innovates from the principle of constraint, so as to simultaneously achieve stable maintenance of rotor speed and rapid reset after rubbing under non-ideal drive conditions. Summary of the Invention

[0005] To address the rotor instability and inability to reset caused by continuous ring constraints in existing technologies, this invention aims to provide a backup bearing device based on a discrete multi-point limit and reset mechanism. This device constructs a discontinuous, flexibly adjustable "polygon-like" operating boundary to achieve the following core functions: ① limiting rotor movement within a finite eccentricity to avoid large-scale loss of control; ② actively generating a restoring torque pointing towards the axis when rotor rubbing occurs, through the asymmetric action of discrete contact points, forcibly guiding the rotor to reset and breaking the continuous contact state; ③ maintaining the original rotor speed to the maximum extent under both dry and lubricated conditions, adapting to non-ideal drive characteristics.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A backup bearing device for suppressing rotor-stator contact faults includes a suspension beam and a mounting frame. A motor is mounted on the suspension beam. A disc and an annular guide rail frame are movably arranged inside the mounting frame. The disc is coaxially sleeved inside the annular guide rail frame, and the disc and the annular guide rail frame are movably fitted together. A gap is reserved between the inner wall of the mounting frame and the outer wall of the annular guide rail frame. The mounting frame and the annular guide rail frame are fixedly connected by bolts. A rotor is fixedly connected to the axis of the disc. The top of the rotor extends to directly below the motor. The output shaft of the motor and the rotor are connected by a flexible coupling. A gap is reserved between the inner wall of the annular guide rail frame and the outer wall of the disk. Four channels are arranged in a ring array on the outer wall of the annular guide rail frame. Each channel is provided with a limit pin. The end of the limit pin is provided with a telescopic structure and abuts against the disk. A key phase mark is provided on the outside of the rotor, and a speed sensor is provided on the outside of the flexible coupling at the position corresponding to the key phase mark to acquire the key phase signal; Multiple displacement sensors arranged in a ring array are provided on the outer side of the ring guide rail frame to collect displacement data of the disk in the y and z directions.

[0007] Preferably, the disc and the annular guide rail frame are at the same horizontal height as the mounting frame, and the disc, the annular guide rail frame and the mounting frame are arranged in parallel.

[0008] Preferably, the annular guide rail frame is configured as a rigid annular structure, the number of bolts is set to four, and all four bolts penetrate the four side wall plates of the frame and are threadedly engaged with the through holes. The ends of the bolts abut against the outer wall of the annular guide rail frame.

[0009] Preferably, the rotor is in a vertical position, and the surface of the disk has concentric circle patterns.

[0010] Preferably, the telescopic structure adopts a threaded pair, and a scale ring is provided on the outer side of the threaded pair.

[0011] Preferably, an arc-shaped liner is embedded at the end of the threaded pair facing the disk, and the arc-shaped liner is made of a high-hardness wear-resistant material, and the radius of curvature of the arc-shaped liner is slightly larger than the thickness of the disk.

[0012] Preferably, the end of the suspension beam away from the motor is fixed to the support frame, and a positioning frame is provided on one side of the support frame, with the positioning frame located directly below the motor.

[0013] Preferably, a horizontal plate is fixedly connected to one side of the support frame, and an opening is provided on the surface of the horizontal plate for a flexible coupling to pass through. The flexible coupling integrates ball bearings for connecting and driving the rotor.

[0014] Preferably, the positioning frame includes a top frame, a bottom plate, and at least four support columns. The top frame is positioned directly above the bottom plate, and the support columns are fixed between the top frame and the bottom plate.

[0015] The present invention also provides a test method for a backup bearing device for suppressing rotor-stator contact faults, comprising the following steps: S1. System calibration: Start the motor to drive the rotor to run under no-load. Change the output frequency stepwise in the range of 5-30Hz through the frequency converter. Use the torque measurement module to collect torque data at each stable speed. Use a third-order polynomial to fit and obtain the accurate torque-speed characteristic curve of the motor. S2, Damping Identification: Turn off the motor to make the rotor stand still, manually give the disk an initial displacement along the y direction using a precision push rod and then release it. Record the free decay vibration curve of the disk through the displacement sensor, and calculate the equivalent viscous damping coefficient of the system based on the logarithmic decay rate. S3. Comparative test of traditional dry friction guide sleeve: Install a traditional complete annular guide sleeve with a dry inner wall to replace the limiting pin. After laser alignment, start the motor and run it at the target speed for 5 minutes. Then, use a controllable impact hammer to apply a known impulse in the y direction to simulate sudden rotor imbalance. Continuously collect speed and displacement data until the rotor stops completely or enters a stable reverse vortex state. Analyze the data, calculate the collision recovery coefficient, and record the speed decay time and maximum vibration amplitude. S4. Comparison test of traditional lubrication guide sleeve: Remove the dry friction guide sleeve, clean it, and apply the specified grease evenly to its inner wall. Repeat step S3. Focus on observing and recording whether the rotor falls into a full-annular positive whirl state, and calculate the recovery coefficient under this state. S5. Performance verification test of constraint element including limit pins: Remove the traditional guide sleeve and install four limit pins; use the threaded pair to precisely adjust the distance from the tip of the arc-shaped bushing to the theoretical axis of the rotor to the same set value to form the nominal constraint clearance; keep the disk surface dry and repeat the impact step of S3 at the same target speed. The following data should be monitored and recorded: a. The magnitude of the decrease in rotor speed after the impact and the time it takes to recover to a stable value; b. Does the shaft trajectory show that after the rotor intermittently impacts the limiting pin, its motion envelope exhibits a centripetal convergence trend rather than continuous whirling? c. Through trajectory analysis, verify whether the rotor is forcibly guided back to the center region of the "quasi-square" boundary; S6. Data Processing and Analysis: Noise reduction was performed on all displacement data collected from the experiment using a 5th-order Butterworth low-pass filter; time-domain plots of y(t) and z(t), yz-plane axis trajectory plots, and rotor angular velocity ω(t) variation curves were plotted respectively; the essential differences in the lateral vibration intensity, speed stability, and motion mode of the rotor under the three working conditions in S3-S5 were compared and analyzed.

[0016] Compared with the prior art, the present invention has the following technical effects: 1. By transforming the traditional "continuous surface constraint" into "discrete point limit", the full-ring contact between the rotor and stator is fundamentally avoided, thereby completely eliminating the two harmful motion modes of "reverse whirl" or "continuous forward whirl". In non-ideal drive scenarios such as without speed feedback control, it can effectively suppress speed instability, harmful whirl and friction damage caused by the contact between the rotor and stator, and solve the dilemma of traditional backup bearings that either cause speed instability or cause continuous wear.

[0017] 2. The "quasi-square" boundary formed by multiple limiting pins has non-axisymmetric characteristics, which can produce a directional recovery effect on the eccentric rotor, realizing a virtuous cycle of "impact-reset" rather than the vicious cycle of "contact-stickiness" in traditional solutions.

[0018] 3. By simply adjusting the radial position of the four limit pins, the size of the constraint gap can be changed, thereby balancing between "rapid reset response" and "low impact force" to meet the different requirements of various rotating machines for safety margin and vibration tolerance.

[0019] 4. Whether in a dry or lubricated state, this structure can work effectively, maintaining the rotor speed within an acceptable range, making it particularly suitable for a wide range of applications with unsatisfactory drive characteristics (such as those without speed feedback control). Attached Figure Description

[0020] Figure 1 This is a perspective view of the backup bearing device for suppressing rotor-stator contact faults in this invention.

[0021] Figure 2 This is a front view of the backup bearing device for suppressing rotor-stator contact faults in this invention.

[0022] Figure 3 This is a right view of the backup bearing device for suppressing rotor-stator contact faults in this invention.

[0023] Figure 4 This is a schematic diagram showing the distribution of the disk, the annular guide rail frame, and the constraint elements in this invention.

[0024] Figure 5This is a schematic diagram showing the distribution of the annular guide rail frame, constraint elements, and displacement sensors in this invention.

[0025] Figure 6 The diagrams show the time-domain y-direction displacement, time-domain z-direction displacement, axis trajectory, and time-frequency diagram of the dry friction contact test under condition one in this embodiment.

[0026] Figure 7 The diagrams show the time-domain y-direction displacement, time-domain z-direction displacement, axis trajectory, and time-frequency diagram of the wet contact test under condition two in this embodiment.

[0027] Figure 8 The diagrams show the time-domain y-direction displacement, time-domain z-direction displacement, shaft center trajectory, and time-frequency diagram for the pin contact test under condition three in this embodiment.

[0028] Numbering on the map: Rotor-1; Disc-2; Annular guide rail frame-3; Motor-4; Speed ​​sensor-5; Displacement sensor-6; Flexible coupling-7; Positioning frame-8; Support frame-9; Mounting frame-10; Limit pin-11; Horizontal plate-12; Suspension beam-13; Bolt-14; Arc-shaped bushing-15; Top frame - 801; bottom plate - 802; support column - 803. Detailed Implementation

[0029] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0030] In this invention, various aspects of the invention are described with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. Embodiments of the invention are not limited to those depicted in the drawings. It should be understood that the invention is implemented through any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the invention disclosed may be used alone or in any suitable combination with other aspects of the invention disclosed.

[0031] like Figure 1-5 As shown, a backup bearing device for suppressing rotor-stator contact faults includes a suspension beam 13 and a mounting frame 10. A motor 4 is mounted on the suspension beam 13. A disc 2 and an annular guide frame 3 are movably arranged inside the mounting frame 10. The disc 2 is coaxially sleeved inside the annular guide frame 3, and the disc 2 and the annular guide frame 3 are movably fitted. A gap is reserved between the inner wall of the mounting frame 10 and the outer wall of the annular guide frame 3. The mounting frame 10 and the annular guide frame 3 are fixedly connected by bolts 14. A rotor 1 is fixedly connected to the axis of the disc 2. The top of the rotor 1 extends directly below the motor 4. The output shaft of the motor 4 and the rotor 1 are connected by a flexible coupling 7.

[0032] A gap is reserved between the inner wall of the annular guide frame 3 and the outer wall of the disk 2. Four channels arranged in a circular array are provided on the outer wall of the annular guide frame 3. Each channel is equipped with a limit pin 11. The four limit pins 11 serve as the core constraint elements and are evenly distributed circumferentially on the inner side of the annular guide frame 3. The ends of the limit pins 11 are equipped with telescopic structures and abut against the disk 2; the four limit pins 11 are independently adjustable.

[0033] A key phase mark is set on the outside of the rotor 1, and the key phase mark is arranged vertically; a speed sensor 5 is set on the outside of the flexible coupling 7 and at the position corresponding to the key phase mark, for acquiring key phase signals; Multiple displacement sensors 6 arranged in a ring array are provided on the outside of the ring guide frame 3 to collect displacement data of the disk 2 in the y and z directions.

[0034] Furthermore, in the above technical solution, the disc 2 and the annular guide rail frame 3 are both at the same horizontal height as the mounting frame 10, and the disc 2, the annular guide rail frame 3 and the mounting frame 10 are arranged in parallel.

[0035] Furthermore, in the above technical solution, the annular guide rail frame 3 is set as a rigid annular structure, the number of bolts 14 is set to four, and all four bolts 14 penetrate through the four side wall plates of the mounting frame 10 and are threadedly engaged with the through holes. The ends of the bolts 14 abut against the outer wall of the annular guide rail frame 3.

[0036] Furthermore, in the above technical solution, the rotor 1 is in a vertical position, and the surface of the disk 2 has concentric circle textures.

[0037] Furthermore, in the above technical solution, the telescopic structure adopts a threaded pair, which is independently installed on the annular guide frame 3, enabling high-precision fine adjustment. A graduated ring is provided on the outer side of the threaded pair. This allows for independent and precise adjustment of the radial position of the pins, with an adjustment resolution of no less than 0.01 mm. By synchronously or asynchronously adjusting the radial position of the four limiting pins 11, a nearly square constraint boundary with customizable clearance can be formed within the rotation plane of the disk 2. This constraint boundary provides non-axisymmetric discrete radial limiting for the rotor 1.

[0038] Furthermore, in the above technical solution, an arc-shaped bushing 15 is embedded at the end of the threaded pair facing the disk 2, and the arc-shaped bushing 15 is made of a high-hardness wear-resistant material, with a radius of curvature slightly larger than the thickness of the disk 2, in order to optimize contact stress.

[0039] Furthermore, in the above technical solution, the end of the suspension beam 13 away from the motor 4 is fixed to the support frame 9, and a positioning frame 8 is provided on one side of the support frame 9, with the positioning frame 8 located directly below the motor 4. The support frame 9 is used to support the motor 4.

[0040] Furthermore, in the above technical solution, a horizontal plate 12 is fixedly connected to one side of the support frame 9, and an opening is provided through the surface of the horizontal plate 12 for the flexible coupling 7 to pass through. The flexible coupling 7 integrates ball bearings inside, which are used to connect and drive the rotor 1 to reduce the transmission of lateral vibration and compensate for misalignment.

[0041] Furthermore, in the above technical solution, the positioning frame 8 includes a top frame 801, a bottom plate 802, and at least four support columns 803. The top frame 801 is correspondingly positioned directly above the bottom plate 802, and the multiple support columns 803 are fixed between the top frame 801 and the bottom plate 802.

[0042] First, the positioning frame 8 and support frame 9 are leveled and fixed on a rigid platform. The motor 4 is installed on the support frame 9 and initially connected to the rotor 1 via the flexible coupling 7. Then, the rotor assembly with the disc 2 is installed, and a precision level is used to ensure the rotor 1 is vertical. The core step is the installation and adjustment of the discrete multi-point limit reset mechanism. The annular guide rail frame 3 is securely fixed to the mounting frame 10 using high-strength bolts 14. After installation, a laser alignment instrument is used to precisely calibrate the inner hole of the annular guide rail frame 3. By fine-tuning and fixing the bolts 14, the theoretical center of the annular guide rail frame 3 is ensured to coincide with the ideal rotation axis of the rotor 1 when stationary. This alignment error must be controlled within 0.02 mm, laying the foundation for subsequent precise clearance setting. Then, four limit pins 11 are installed. The adjustment of each limit pin 11 is an independent and precise process. First, the limit pin 11 is screwed into its corresponding fine-tuning threaded mounting seat, and the scale ring at the tail end of the limit pin 11 is zeroed. Using a micrometer or a calibrated feeler gauge, set the target clearance value. In this embodiment, the target clearance value is set to 0.50 mm. Slowly rotate the threaded pair, driving the arc-shaped bushing 15 at the front end of the limiting pin 11 to move radially. Simultaneously, use a non-contact eddy current displacement sensor (temporarily installed at the shaft center) to monitor the distance change between the pin tip and the sensor probe (representing the theoretical shaft center) in real time. When the distance reaches the set value, stop rotating and tighten the anti-loosening nut of the limiting pin 11 to prevent displacement during subsequent vibrations. In this way, complete the independent adjustment of the four limiting pins 11 in sequence, and finally use a feeler gauge to check the uniformity of the clearance around the perimeter to ensure that the formed "quasi-square" constraint boundary is basically symmetrical about the shaft center.

[0043] Based on the backup bearing device for suppressing rotor-stator contact faults in this embodiment, the following methods are used to study the problems of speed instability, lateral vibration, and friction damage caused by rotor-stator contact: S1. System calibration: Start motor 4 to drive rotor 1 to run under no-load. Change the output frequency stepwise in the range of 5-30Hz through frequency converter. Collect torque data at each stable speed using torque measurement module. Use third-order polynomial fitting to obtain the accurate torque-speed characteristic curve of motor 4. S2, Damping Identification: Turn off motor 4 to make rotor 1 stand still, manually give disk 2 an initial displacement along the y direction using a precision push rod and then release it, record the free decay vibration curve of disk 2 through displacement sensor 6 with a high sampling rate, and calculate the equivalent viscous damping coefficient of the system based on the logarithmic decay rate. S3. Comparative test of traditional dry friction guide sleeve: Install a traditional complete annular guide sleeve with a dry inner wall (e.g., friction coefficient μ≥0.55) to replace the limiting pin 11. After laser alignment, start motor 4 to the target speed (e.g., 1200 rpm) and run it stably for 5 minutes. Then, use a controllable impact hammer to apply a known impulse along the y-direction to simulate a sudden imbalance of rotor 1. Continuously collect speed and displacement data until rotor 1 stops completely or enters a stable reverse vortex state. Analyze the data, calculate the collision recovery coefficient, and record the speed decay time and maximum vibration amplitude. S4. Comparison test of traditional lubricated guide sleeve: Remove the dry friction guide sleeve, clean it and apply the specified grease evenly to its inner wall (friction coefficient μ≈0.08), repeat step S3; focus on observing and recording whether rotor 1 falls into a full-circular positive vortex state (i.e. whether the shaft center trajectory continuously adheres to the inner wall of the guide sleeve), and calculate the recovery coefficient in this state. S5. Performance verification test of constraint element including limit pins 11: Remove the traditional guide sleeve and install four limit pins 11; use the threaded pair to precisely adjust the distance from the tip of the arc-shaped bushing 15 to the theoretical axis of the rotor 1 to the same set value (e.g., 0.0005m) to form the nominal constraint clearance; keep the surface of the disk 2 dry and repeat the impact step of S3 at the same target speed. The following data should be monitored and recorded: a. The magnitude of the decrease in rotor speed after the impact and the time it takes to recover to a stable value; b. Does the shaft trajectory show that after the rotor 1 intermittently impacts the limiting pin 11, its motion envelope exhibits a centripetal convergence trend rather than continuous vortexing? c. Through trajectory analysis, verify whether rotor 1 is forcibly guided back to the center region of the "quasi-square" boundary; S6. Data Processing and Analysis: Noise reduction was performed on all displacement data collected from the experiments using a 5th-order Butterworth low-pass filter. Time-domain plots of y(t) and z(t), the yz-plane axis trajectory, and the rotor angular velocity ω(t) variation curve were plotted. The essential differences in lateral vibration intensity, speed stability, and motion mode of rotor 1 under the three operating conditions in S3-S5 (i.e., conventional dry friction, conventional lubrication, and the limiting pin 11 of this invention) were compared and analyzed. This was to quantify the technical effectiveness of the backup bearing device in maintaining speed and suppressing continuous whirl.

[0044] Before the formal comparative test, system calibration must be completed. Motor 4 is started, and under no-load conditions, the rotor 1's speed is gradually increased from 5Hz to 30Hz via a frequency converter. After stabilizing for one minute at each frequency point, stable torque and speed data are collected via a torque flange. The inherent torque-speed characteristic curve of motor 4 is plotted and fitted for load characteristic correction in subsequent analysis. Next, sensor calibration is performed: a standard micrometer platform is used to perform "voltage-displacement" linear calibration on the eddy current displacement sensors in both directions; by comparing the speed set by the frequency converter with the speed calculated by speed sensor 5 based on the key phase signal, the speed measurement error is ensured to be less than 0.5%. Finally, system damping identification is performed: the motor power is cut off, and rotor 1 is allowed to rotate freely until it stops, recording its natural speed decay curve; simultaneously, while rotor 1 is stationary, a force gauge is used to push disk 2 to a certain displacement and then suddenly release it, recording its free oscillation decay curve. Combining these two sets of data, the overall equivalent viscous damping coefficient of the system can be calculated.

[0045] Design and execute comparative verification experiments: To objectively evaluate the effectiveness of the invention, three control test groups were designed, all under the same initial conditions (ambient temperature, initial dynamic balance of the rotor), and the impact simulation used the same controllable electromagnetic impact hammer to provide repeatable impact impulse.

[0046] Test Group A (Conventional Dry Friction Guide Sleeve): The limiting pin 11 of this invention was removed, and a complete annular steel guide sleeve with a sandblasted inner surface was installed. Its inner surface and the disc contact surface were thoroughly cleaned with anhydrous ethanol to maintain a dry contact state. The measured static friction coefficient was approximately 0.56. Motor 4 was started, and rotor 1 was accelerated to 1200 rpm and run stably for 5 minutes, collecting baseline data under undisturbed conditions. Subsequently, an impact hammer was used to apply a momentary impact to the rotor along the y-direction (simulating an initial disturbance with a radial velocity of approximately 12 cm / s). Rotational speed, y-direction, and z-direction displacement data were continuously collected until rotor 1 completely stopped rotating. The experiment observed that rotor 1 rapidly lost stability after the impact, and the rotational speed linearly decreased to zero within approximately 2.1 seconds. Figure 6As shown, the shaft trajectory exhibits a continuously expanding reverse vortex, and the final trajectory envelope fills the entire inner wall of the guide sleeve, indicating that rotor 1 is in a state of repeated and violent impact.

[0047] Test Group B (Conventional Lubricated Guide Sleeve): The guide sleeve of Test Group A was disassembled, cleaned, and a layer of the specified lithium-based grease was evenly applied to its inner wall. The same start-up, stabilization, and impact processes were repeated (impact radial velocity approximately 64 cm / s). The test showed that the rotational speed of rotor 1 decreased by about 35% after the impact, and then stopped decreasing, instead maintaining a low, stable value. Figure 7 As shown, the shaft trajectory converges into an approximately perfect circle with a radius equal to the guide sleeve gap in a very short time (about 0.3 seconds). The center of rotor 1 remains in contact with the lubricated inner wall, thus entering the "full-circular positive vortex" state, until manual shutdown, and fails to automatically reset.

[0048] Test Group C (Pin Mechanism of the Invention): The device of the invention was reinstalled, ensuring that the gap between the four limiting pins 11 had been precisely adjusted to 0.50 mm as in the first step, and the surface of the disc 2 was kept dry. A moderate-intensity impact (radial velocity approximately 42 cm / s) was applied at the same stable rotational speed of 1200 rpm as the first two groups. The experimental phenomena were fundamentally different from the first two groups. For example... Figure 8 As shown, the rotational speed of rotor 1 briefly decreased (approximately 15%) after the impact, but began to recover after about 0.8 seconds, eventually stabilizing at over 98% of the initial speed. The shaft trajectory diagram clearly shows that after the point representing the center of rotor 1 deviated, its movement path briefly intersected with the virtual boundary formed by the positions of the four limiting pins 11 several times (i.e., collision events). Subsequently, the overall envelope of the trajectory showed a clear trend of convergence towards the central region. Approximately 1.5 seconds after the impact, the shaft center of rotor 1 had basically returned to the central position, with only very small random fluctuations, successfully achieving a virtuous cycle of "impact-reset".

[0049] All time-domain displacement data collected from the three sets of experiments were imported into MATLAB software. First, a 5th-order Butterworth low-pass digital filter with a cutoff frequency of 200Hz was used for filtering to eliminate high-frequency electrical noise. Then, time-domain plots of y(t) and z(t) displacement, yz-plane shaft center trajectory plots, and rotor angular velocity ω(t) versus time were plotted for each group. Key indicators were quantitatively extracted and compared: the maximum rate of decrease in rotor speed after impact and the time to recover to a stable value were calculated; the root mean square value of the radial displacement of the shaft center trajectory was calculated to quantify the vibration intensity; and the long-term morphology of the trajectory was analyzed to determine whether a continuous contact eddy mode occurred. The data analysis results were summarized in charts, quantitatively demonstrating that the present invention (experimental group C) is significantly superior to the traditional annular guide sleeve scheme (i.e., experimental groups A and B) in suppressing speed decrease, shortening recovery time, reducing steady-state vibration amplitude, and most importantly, avoiding any form of continuous full-contact eddy.

[0050] As can be seen from the detailed construction and verification process of the above specific embodiments, the backup bearing device and method proposed in this invention can effectively solve the problems of speed instability and vibration in rotor-stator contact faults, and have outstanding technical effects and practical value.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A backup bearing device for suppressing rotor-stator contact faults, comprising a suspension beam (13) and a mounting frame (10), characterized in that: A motor (4) is installed on the suspension beam (13). A disc (2) and an annular guide frame (3) are movably arranged inside the mounting frame (10). The disc (2) is coaxially sleeved inside the annular guide frame (3), and the disc (2) and the annular guide frame (3) are movably fitted. A gap is reserved between the inner wall of the mounting frame (10) and the outer wall of the annular guide frame (3). The mounting frame (10) and the annular guide frame (3) are fixedly connected by bolts (14). A rotor (1) is fixedly connected at the axis of the disc (2). The top of the rotor (1) extends to directly below the motor (4). The output shaft of the motor (4) and the rotor (1) are connected by a flexible coupling (7). A gap is reserved between the inner wall of the annular guide rail frame (3) and the outer wall of the disk (2). Four channels are provided on the outer wall of the annular guide rail frame (3) in a circular array. Each channel is provided with a limit pin (11). The end of the limit pin (11) is provided with a telescopic structure and abuts against the disk (2). A key phase mark is provided on the outside of the rotor (1), and a speed sensor (5) is provided on the outside of the flexible coupling (7) and at the position corresponding to the key phase mark, for acquiring the key phase signal; Multiple displacement sensors (6) arranged in a ring array are provided on the outside of the ring guide rail frame (3) to collect displacement data of the disk (2) in the y and z directions.

2. The backup bearing device for suppressing rotor-stator contact faults according to claim 1, characterized in that: The disc (2) and the annular guide rail frame (3) are both at the same horizontal height as the mounting frame (10), and the disc (2), the annular guide rail frame (3) and the mounting frame (10) are arranged in parallel.

3. The backup bearing device for suppressing rotor-stator contact faults according to claim 1, characterized in that: The annular guide rail frame (3) is configured as a rigid annular structure. The number of bolts (14) is set to four, and all four bolts (14) penetrate through the four side walls of the mounting frame (10) and are threaded into the through holes. The ends of the bolts (14) abut against the outer wall of the annular guide rail frame (3).

4. The backup bearing device for suppressing rotor-stator contact faults according to claim 1, characterized in that: The rotor (1) is in a vertical position, and the surface of the disk (2) has concentric circle textures.

5. The backup bearing device for suppressing rotor-stator contact faults according to claim 1, characterized in that: The telescopic structure uses a threaded pair, and a graduated ring is provided on the outside of the threaded pair.

6. The backup bearing device for suppressing rotor-stator contact faults according to claim 5, characterized in that: The threaded pair is inlaid with an arc-shaped liner (15) at the end facing the disk (2), and the arc-shaped liner (15) is made of a high-hardness wear-resistant material. The radius of curvature of the arc-shaped liner (15) is slightly larger than the thickness of the disk (2).

7. The backup bearing device for suppressing rotor-stator contact faults according to claim 1, characterized in that: The end of the suspension beam (13) away from the motor (4) is fixed on the support frame (9), and a positioning frame (8) is provided on one side of the support frame (9), and the positioning frame (8) is located directly below the motor (4).

8. The backup bearing device for suppressing rotor-stator contact faults according to claim 7, characterized in that: A horizontal plate (12) is fixedly connected to one side of the support frame (9). A hole is provided on the surface of the horizontal plate (12) for the flexible coupling (7) to pass through. The flexible coupling (7) integrates ball bearings inside and is used to connect and drive the rotor (1).

9. The backup bearing device for suppressing rotor-stator contact faults according to claim 7, characterized in that: The positioning frame (8) includes a top frame (801), a bottom plate (802) and at least four support columns (803). The top frame (801) is positioned directly above the bottom plate (802), and the multiple support columns (803) are fixed between the top frame (801) and the bottom plate (802).

10. A test method for a backup bearing device for suppressing rotor-stator contact faults based on any one of claims 1-9, characterized in that: Includes the following steps: S1, System calibration: Start the motor (4) to drive the rotor (1) to run under no-load. Change the output frequency stepwise in the range of 5-30Hz through the frequency converter. Collect torque data at each stable speed using the torque measurement module. Use a third-order polynomial to fit and obtain the accurate torque-speed characteristic curve of the motor (4). S2, Damping identification: Turn off the motor (4) to make the rotor (1) stand still, use a precision push rod to manually give the disk (2) an initial displacement along the y direction and then release it, record the free decay vibration curve of the disk (2) through the displacement sensor (6), and calculate the equivalent viscous damping coefficient of the system based on the logarithmic decay rate; S3. Comparison test of traditional dry friction guide sleeve: Install a traditional complete annular guide sleeve with dry inner wall to replace the limiting pin (11). After laser alignment, start the motor (4) until the target speed is stable for 5 minutes. Then, use a controllable impact hammer to apply a known impulse in the y direction to simulate the sudden imbalance of the rotor (1). Continuously collect speed and displacement data until the rotor (1) stops completely or enters a stable reverse vortex state. Analyze the data, calculate the collision recovery coefficient, and record the speed decay time and maximum vibration amplitude. S4. Comparison test of traditional lubrication guide sleeve: Remove the dry friction guide sleeve, clean it and apply the specified grease evenly to its inner wall, repeat step S3; focus on observing and recording whether the rotor (1) falls into the full-annular positive vortex state, and calculate the recovery coefficient in this state; S5. Performance verification test of constraint element including limit pins (11): Remove the traditional guide sleeve and install four limit pins (11); use the threaded pair to precisely adjust the distance from the tip of the arc-shaped bushing (15) to the theoretical axis of the rotor (1) to the same set value to form the nominal constraint gap; keep the surface of the disk (2) dry and repeat the impact step of S3 at the same target speed. The following data should be monitored and recorded: a. The decrease in rotor (1) speed after the impact and the time to recover to a stable value; b. Does the shaft trajectory show that after the rotor (1) intermittently impacts the limiting pin (11), its motion envelope shows a centripetal convergence trend rather than continuous vortexing? c. Through trajectory analysis, verify whether the rotor (1) is forcibly guided back to the center region of the "quasi-square" boundary; S6. Data processing and analysis: For all displacement data collected in the experiment, a 5th-order Butterworth low-pass filter was used for noise reduction; time-domain diagrams of y(t) and z(t), axis trajectory diagrams of yz plane and rotor angular velocity ω(t) variation curves were plotted respectively; the essential differences in the lateral vibration intensity, speed stability and motion mode of rotor (1) under the three working conditions in S3-S5 were compared and analyzed.

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