CN111649921A - A rotating machinery fault diagnosis and testing system and working method - Google Patents

Abstract

The invention discloses a fault diagnosis and testing system for rotating machinery, which is an experimental bench of a single-disc rotor system supported by a sliding bearing. It also includes a detection device, which is composed of an X-direction eddy sensor, a Y-direction eddy sensor, a data acquisition card, and a computer. The X-direction eddy sensor, Y-direction eddy sensor, piezoelectric sensor and data acquisition The card is connected, and the data acquisition card is communicated with the computer; mutual resistance is formed through the contact between the rubbing device and the single disc rotor, so as to change the signals collected by the X-direction eddy sensor and the Y-direction eddy sensor. The computer is provided with The virtual simulator software processes and analyzes the data sent by the data acquisition card, and adds a rotating machinery fault detection system of the detection device. Compared with the traditional test instrument, the test accuracy is higher.

Description

A rotating machinery fault diagnosis and testing system and working method

technical field

The invention belongs to the field of machinery, and in particular relates to a fault diagnosis and testing system for rotating machinery and a working method.

Background technique

Rotating machinery fault diagnosis is an important part of equipment fault diagnosis. With the development of large-scale, high-speed, continuous and automatic rotating machine equipment, the quality requirements for equipment management and maintenance personnel are also getting higher and higher. Ensuring efficient and safe production and reducing downtime caused by faults are the prerequisites for enterprises to improve economic and social benefits, and equipment condition monitoring and fault diagnosis technology will provide an effective solution for this.

The rubbing between rotating parts and stationary parts of rotating machinery is a common fault in operation. The rubbing behavior produces very complex movements of the rotor. Therefore, monitoring the working state of rotating machinery, accurately analyzing and diagnosing vibration faults, and early detection of equipment faults and their causes are of great significance to ensure the safe and stable operation of equipment and prevent major accidents. In order to deeply explore the early rubbing fault characteristics of rotating machinery, an experimental bench for a single-disk rotor system supported by sliding bearings was built, and eddy current sensors and virtual instruments were used to form a rotating machinery rubbing detection system. Analysis and spectrum analysis, and use of various characteristic information of faults to diagnose faults of rotating machinery equipment can effectively improve the accuracy of fault diagnosis.

SUMMARY OF THE INVENTION

Purpose of the invention: The purpose of the present invention is to solve the deficiencies in the prior art, introduce the detection device technology into the rotating machinery fault detection system, use the software and the eddy current sensor as the software and hardware platform, detect the vibration signal of the rotating machinery, and detect the vibration signal of the rotating machinery. The time domain waveform, frequency spectrum, rotor axis motion trajectory and other comprehensive feature quantities are analyzed and processed, so that the fault of the rotating machinery can be accurately judged. The use of the detection device improves the accuracy of fault diagnosis.

Technical solution: The fault diagnosis and testing system for rotating machinery described in the present invention is an experimental bench for a single-disc rotor system supported by sliding bearings. The grinding device is composed of the motor mounted on the mounting plate, the sliding bearings are arranged on both ends of the single disc rotor, the sliding bearings are mounted on the mounting plate through the bearing seat, and one end of the single disc rotor is connected with the output shaft of the motor, The output shaft of the motor, the rotating shaft of the single-disc rotor and the sliding bearing are located on the same axis, the friction device is arranged around the single-disc rotor, and a detection device is also included. The detection device is composed of X-direction eddy sensors, Y The direction eddy sensor, the data acquisition card, and the computer are composed. The X-direction eddy sensor and the Y-direction eddy sensor are respectively arranged on one side of the single disc rotor, so that the X-direction eddy sensor and the Y-direction electric eddy sensor on the same plane are The eddy sensors are perpendicular to each other, the X-direction eddy sensor and the Y-direction eddy sensor are connected with a data acquisition card, and the data acquisition card is communicated with the computer; mutual resistance is formed by contacting the rubbing device with the single-disc rotor to change the For the signals collected by the X-direction eddy sensor and the Y-direction eddy sensor, the computer is provided with virtual simulator software to process and analyze the data sent by the data acquisition card.

Further, the rubbing device is composed of a bolt and a fixing seat, the fixing seat is installed on the mounting plate, located on one side of the single disc rotor, the fixing seat is provided with a through hole, and the bolt is installed in the through hole. , so that the direction of the bolt coincides with the axis of the single-disk rotor.

A working method of a fault diagnosis and testing system for rotating machinery, the working method is based on software in a technical machine, and the details are as follows: the software design is constructed on a Windows XP system by using the LabVIEW programming language, and on the software platform, the front panel parameter control is set. The data acquisition card is used for data acquisition, and the acquired data is analyzed and processed through the software system. The AI Acquire Waveforms function is used in the program to collect the data from two sensors at the same time, and the Index Array function is used to introduce the two signals respectively; , the signals in the horizontal and vertical directions are respectively sent to the Graph control to display the waveform diagram. At the same time, the signals in the two directions are superimposed on an XY Graph control for display, and the axis trajectory diagram of the rotor can be obtained; and the LabVIEW software is used to analyze the signals. Waveform characteristic analysis in time domain and frequency domain to identify and diagnose rubbing faults of rotating machinery The shaft center motion trajectory parameters and vibration spectrum are used to identify and diagnose rubbing faults.

Further, the time-domain waveform is the relationship curve of the vibration parameter changing with time. When the rotating machinery is in normal operation, the time-domain waveform of the vibration signal under ideal conditions is a smooth sinusoidal curve, and the X-direction and Y-direction rotors collected by the software in real time The vibration waveform, as shown in Figure 2, can be judged from the time domain waveform that the rotor has undergone dynamic and static rubbing; high-frequency components are superimposed on the original sinusoidal signals in the X-axis and Y-axis directions, and the waveform is unstable, while the vibration waveform in the Y-axis direction exists. Obvious clipping and distortion of the waveform indicate that the dynamic and static rubbing of the rotor is more serious, especially the rotor rubbing in the Y-axis direction. Since the displacement of the rotor is limited at the rubbing position in this direction, the "peak" of the vibration waveform disappears. It becomes more "flat"; the signs indicate that the single-disc rotor has entered the mid-term wear stage; in order to explore the reasons for the rubbing failure of the rotor, the axis motion trajectory parameters of the single-disc rotor during the rubbing vibration are collected, and the time domain The waveform characteristics are fully analyzed.

Further, the single-disk rotor axis motion track parameters during the collection of rubbing vibration are as follows:

a. Trajectory characteristics of rotor axis

The shaft center trajectory is obtained by using the X-direction eddy sensor and the Y-direction eddy sensor that are perpendicular to each other in the same plane of the rotating shaft to collect data at the same time. Draw a graph for the abscissa and the Y direction data as the ordinate;

The reasons for the whirl motion of the single-disc rotor may be rotor unbalance, poor alignment, and static and dynamic rubbing; the whirl trajectories caused by different reasons are not the same, which also shows that different rotor shafts are relative to the bearing seat. Motion trajectory; when the rotating machinery is in normal operation, the time-domain waveform of the vibration signal is a sine curve; the mathematical expression of two mutually perpendicular sine signals is

x(t)=A _x cos(ω _x t+φ _x )=A _x cos(2πf _x t+φ _x ) (1)

y(t)=A _y cos(ω _y t+φy)=A _y cos(2πf _y t+φ _y ) (2)

When the frequencies of the two sinusoidal periodic signals are the same, that is, f _x =f _y , the trajectory is generally an ellipse;

Apply XY Graph on the software platform to display the Lissajous graph to measure the rotor axis trajectory, and judge the rotor running state and fault state from this; The sine law changes, among which, assuming that the number of data points, amplitude and frequency are the same, when the phase difference between them is equal to 90°, it is a circle. It can be seen that if the rotor has no rubbing fault, under ideal conditions, The running track of the shaft center should be a circle; if A _x ≠ A _y , that is, when the amplitudes of the rotor in the x and y directions are not equal, the displayed figure is an ellipse;

When a vibration fault occurs in a rotating machine, the time domain waveform is distorted instead of a sinusoid, so the axis motion trajectory is not circular;

The analysis is carried out through some typical trajectory patterns of the single-disc rotor running under different fault conditions, the experimentally measured rotor axis running trajectory patterns after wavelet packet de-noising, and the fault symptom table mapped by the typical trajectory of the single-disc rotor axis. , and then according to the time domain waveform of the rotor vibration, it has been judged that the rotor has a serious rubbing fault, and the axis running track shows the cause of the fault; according to the D'Alembert's principle, the rotor axis motion equation caused by the rotor unbalance is:

where m is the mass of the rotor, c is the internal and external damping coefficient when the rotor rotates, k is the bending stiffness of the shaft, ζ is the eccentricity of the rotor, and ω is the angular velocity of the rotor rotating;

b. Measurement of radial displacement of rotor shaft

The radial vibration displacement value of the shaft center of the single-disk rotor is the most intuitive digital quantity to judge the severity of the rotor rubbing fault; when the running rotor vibrates radially, the distance between its surface and the eddy current sensor changes with time, and the sensor The output voltage also changes accordingly; the LabVIEW program in the application software can measure the voltage value when the distance between the rotor surface is the smallest and the largest voltage value, and the peak-to-peak value is the voltage extreme value when the rotor vibrates radially, and its corresponding Non-electricity is the maximum radial displacement of the shaft center; when the running rotor has radial rubbing vibration, the output voltage of the eddy current sensor changes in direct proportion to the distance between the plane coil and the rotor;

Use Amplitude and levels.vi of LabVIEW in the software to detect the output voltage when the plane coil of the eddy current sensor is farthest from the rotor, display the voltage value of the experimental data, and the experimental data when the distance is the closest is the voltage value, peak-peak voltage value; -The peak value is the maximum voltage output change of the eddy current sensor. Using the measured data of the quasi-linear segment during the calibration of the eddy current sensor and the Linear Fit.vi of LabVIEW, the least squares fitting straight line equation is obtained as

y=6.11+0.91x (5)

From this, the slope is 0.91, which is also the sensitivity of the eddy current sensor, and its mathematical expression is

where Δy is the sensor voltage output increment, and Δx is the rotor vibration displacement.

Using the formula (6), the maximum radial displacement of the shaft center corresponding to it can be obtained, which is enough to explain the severity of the rotor rubbing failure.

Further, the rotor vibration spectrum analysis is as follows:

In order to accurately judge the fault vibration frequency, the detection signal is further analyzed in the frequency domain. In most cases, the rotating machinery vibration signal is a complex signal superimposed by a variety of excitation signals, which can be decomposed into a series of harmonic components. The component represents the response of the corresponding frequency excitation in the linear system, and each harmonic component contains the amplitude and phase characteristic quantities;

Using the spectrum analysis program designed by LabVIEW, in order to reduce the leakage effect, before the Fourier transform of the rotor vibration signal, the window function is used to weight it, and the actual vibration spectrum analysis diagram is analyzed, and it can be clearly seen that the fundamental frequency is the rotor's The rotational frequency is exactly the same as the set rotational speed; there is a peak at twice the fundamental frequency, which is one of the important characteristic signals of rotor rubbing, indicating that the axial vibration of the rotor is stronger than the radial vibration, which is in line with the comprehensive rubbing vibration fault. Characteristics.

Beneficial effects: The present invention introduces the detection device technology into the rotating machinery fault detection system, uses software and eddy current sensors as software and hardware platforms to detect the rotating machinery vibration signal, By analyzing and processing such comprehensive feature quantities, the faults of rotating machinery can be accurately judged, and the accuracy of fault diagnosis is improved through the use of the detection device; therefore, the rotating machinery fault detection system of the detection device is added, compared with the traditional test instrument with high test accuracy.

Description of drawings

Figure 1 is a schematic diagram of the detection device;

Fig. 2 is a rotor vibration waveform diagram;

Fig. 3 is the axis track diagram;

Fig. 4 is the wavelet packet denoising procedure diagram;

Figure 5 is the interface diagram of the radial vibration displacement test of the rotor shaft;

Fig. 6 is a rotating machinery vibration spectrum program diagram;

Fig. 7 is the rotor vibration spectrum plus Hamming window diagram;

Figure 8 is a detailed panel view of the mechanical vibration detector;

9 is a mechanical structure diagram of a rotating machinery fault diagnosis and testing system;

1. Mounting plate; 2. Motor; 3. Single disc rotor; 4. Sliding bearing; 5. Wearing device; 6. Eddy sensor in X direction; 7. Eddy sensor in Y direction.

Detailed ways

A fault diagnosis and testing system for rotating machinery is an experimental bench for a single disc rotor system supported by a sliding bearing. , the motor 2 is mounted on the mounting plate 1, the sliding bearings 4 are arranged on both ends of the single disc rotor 3, the sliding bearings 4 are mounted on the mounting plate 1 through the bearing seat, and one end of the single disc rotor 3 is connected to the motor 2. The output shafts are connected, so that the output shaft of the motor 2, the rotating shaft of the single-disk rotor 3, and the sliding bearing 4 are located on the same axis. The rubbing device 5 is arranged around the single-disk rotor, and also includes a detection device. The detection device It is composed of X-direction eddy sensor 6, Y-direction eddy sensor 7, data acquisition card, and computer. The X-direction eddy sensor 6 and the Y-direction eddy sensor 7 on a plane are perpendicular to each other, and the X-direction eddy sensor 6 and the Y-direction eddy sensor 7 are connected to a data acquisition card, and the data acquisition card is communicated with a computer. By contacting the rubbing device 5 with the single disc rotor 3 to form mutual resistance, to change the signals collected by the X-direction eddy sensor 6 and the Y-direction eddy sensor 7, the computer is provided with virtual simulator software to the data acquisition card The data sent is processed and analyzed; the diameter of the rotating machinery rotor measured is 20.00mm, the eccentricity is 0.2mm, and a rubbing device is set up in the y-axis direction, and the displacement can be adjusted to simulate single or double points. Rubbing failure. The acquisition of the rubbing signal is completed by the PCI-6024E acquisition card, the number of sampling points is set to 1000, the rotor speed is 2340r/min, and the test frequency is 39Hz.

Further, the rubbing device is composed of a bolt and a fixing seat, the fixing seat is installed on the mounting plate, located on one side of the single disc rotor, the fixing seat is provided with a through hole, and the bolt is installed in the through hole. , so that the direction of the bolt coincides with the axis of the single disc rotor;

A working method of a fault diagnosis and testing system for rotating machinery, the working method is based on software in a technical machine, and the details are as follows: the software design is constructed on a Windows XP system by using the LabVIEW programming language, and on the software platform, the front panel parameter control is set. The data acquisition card is used for data acquisition, and the acquired data is analyzed and processed through the software system. The AI Acquire Waveforms function is used in the program to collect the data from two sensors at the same time, and the Index Array function is used to introduce the two signals respectively; , the signals in the horizontal and vertical directions are respectively sent to the Graph control to display the waveform diagram. At the same time, the signals in the two directions are superimposed on an XY Graph control for display, and the axis trajectory diagram of the rotor can be obtained; and the LabVIEW software is used to analyze the signals. Waveform characteristic analysis in time domain and frequency domain to identify and diagnose rubbing faults of rotating machinery The shaft center motion trajectory parameters and vibration spectrum are used to identify and diagnose rubbing faults.

Further, the time-domain waveform is the relationship curve of the vibration parameter changing with time. When the rotating machinery is in normal operation, the time-domain waveform of the vibration signal under ideal conditions is a smooth sinusoidal curve, and the X-direction and Y-direction rotors collected by the software in real time The vibration waveform, as shown in Figure 2, can be judged from the time domain waveform that the rotor has undergone dynamic and static rubbing; high-frequency components are superimposed on the original sinusoidal signals in the X-axis and Y-axis directions, and the waveform is unstable, while the vibration waveform in the Y-axis direction exists. Obvious clipping and distortion of the waveform indicate that the dynamic and static rubbing of the rotor is more serious, especially the rotor rubbing in the Y-axis direction. Since the displacement of the rotor is limited at the rubbing position in this direction, the "peak" of the vibration waveform disappears. It becomes more "flat"; the signs indicate that the single-disc rotor has entered the mid-term wear stage; in order to explore the reasons for the rubbing failure of the rotor, the axis motion trajectory parameters of the single-disc rotor during the rubbing vibration are collected, and the time domain The waveform characteristics are fully analyzed.

Further, the single-disk rotor axis motion track parameters during the collection of rubbing vibration are as follows:

a. Trajectory characteristics of rotor axis

The shaft center trajectory is obtained by using the X-direction eddy sensor and the Y-direction eddy sensor that are perpendicular to each other in the same plane of the rotating shaft to collect data at the same time. Draw a graph for the abscissa and the Y direction data as the ordinate;

The reasons for the whirl motion of the single-disc rotor may be rotor unbalance, poor alignment, and static and dynamic rubbing; the whirl trajectories caused by different reasons are not the same, which also shows that different rotor shafts are relative to the bearing seat. Motion trajectory; when the rotating machinery is in normal operation, the time-domain waveform of the vibration signal is a sine curve; the mathematical expression of two mutually perpendicular sine signals is

x(t)=A _x cos(ω _x t+φ _x )=A _x cos(2πf _x t+φ _x ) (1)

y(t)=A _y cos(ω _y t+φ _y )=A _y cos(2πf _y t+φ _y ) (2)

When the frequencies of the two sinusoidal periodic signals are the same, that is, f _x =f _y , the trajectory is generally an ellipse;

Apply XY Graph on the software platform to display the Lissajous graph to measure the rotor axis trajectory, and judge the rotor running state and fault state from this; The sine law changes, among which, assuming that the number of data points, amplitude and frequency are the same, when the phase difference between them is equal to 90°, it is a circle. It can be seen that if the rotor has no rubbing fault, under ideal conditions, The running track of the shaft center should be a circle; if A _x ≠ A _y , that is, when the amplitudes of the rotor in the x and y directions are not equal, the displayed figure is an ellipse;

When a vibration fault occurs in a rotating machine, the time-domain waveform is distorted instead of a sinusoid, so the axis motion trajectory is not a circle; (e) are some typical trajectory patterns of the rotor when it runs under various fault conditions;

Table 1

The fault symptom table mapped by the typical trajectory of the rotor axis of a single disc is shown in Table 1; as shown in Figure 4, the running trajectory of the rotor axis after wavelet packet de-noising measured in the experiment is analyzed, and then according to the rotor vibration The time-domain waveform of , has judged that the rotor has a serious rubbing fault, and the axis running track indicates the cause of the fault; according to D'Alembert's principle, the rotor axis motion equation caused by rotor unbalance is:

where m is the mass of the rotor, c is the internal and external damping coefficient when the rotor rotates, k is the bending stiffness of the shaft, ζ is the eccentricity of the rotor, and ω is the angular velocity of the rotor rotating;

b. Measurement of radial displacement of rotor shaft

The radial vibration displacement value of the shaft center of the single-disk rotor is the most intuitive digital quantity to judge the severity of the rotor rubbing fault; when the running rotor vibrates radially, the distance between its surface and the eddy current sensor changes with time, and the sensor The output voltage also changes accordingly; the LabVIEW program in the application software can measure the voltage value when the distance between the rotor surface is the smallest and the largest voltage value, and the peak-to-peak value is the voltage extreme value when the rotor vibrates radially, and its corresponding Non-electricity is the maximum radial displacement of the shaft center; when the running rotor has radial rubbing vibration, the output voltage of the eddy current sensor changes in direct proportion to the distance between the plane coil and the rotor; the radial vibration of the rotor shaft center is designed The displacement test interface is shown in Figure 5.

Use Amplitude and levels.vi of LabVIEW in the software to detect the output voltage of the eddy current sensor plane coil when it is farthest from the rotor. The front panel shows the experimental data is 8.24v, the experimental data when the distance is the closest is 6.62v, and the peak-to-peak value is 1.62 v. The peak-to-peak value of 1.62v is the maximum voltage output change of the eddy current sensor. Using the measured data of the standard linear segment of the eddy current sensor calibration and the Linear Fit.vi of LabVIEW, the least squares fitting straight line equation is obtained as

y=6.11+0.91x (5)

From this, the slope is 0.91, which is also the sensitivity of the eddy current sensor, and its mathematical expression is

where Δy is the sensor voltage output increment, and Δx is the rotor vibration displacement.

Using formula (6), it can be obtained that the corresponding maximum radial displacement of the shaft center is 1.78mm, which is enough to illustrate the severity of the rotor rubbing failure.

Further, the rotor vibration spectrum analysis is as follows:

In order to accurately judge the fault vibration frequency, the detection signal is further analyzed in the frequency domain. In most cases, the rotating machinery vibration signal is a complex signal superimposed by a variety of excitation signals, which can be decomposed into a series of harmonic components. The component represents the response of the corresponding frequency excitation in the linear system, and each harmonic component contains the amplitude and phase characteristic quantities;

Figure 6 is a spectrum analysis program designed by LabVIEW. In order to reduce the leakage effect, a window function is used to weight the rotor vibration signal before the Fourier transform is performed. Figure 7 is the actual vibration spectrum analysis diagram, we can clearly see that the fundamental frequency is the rotation frequency of the rotor 39Hz, which is exactly the same as the set rotation speed. The peak at twice the fundamental frequency (78Hz) is one of the important characteristic signals of rotor rubbing, indicating that the axial vibration of the rotor is stronger than the radial vibration, which is in line with the characteristics of the comprehensive rubbing vibration fault in this experiment.

The rotor of the test bench is composed of a relatively light elastic shaft and a disc installed in the middle of the elastic shaft, and the two ends are supported by non-deformable bearings and bearing seats; using this basic structure can reduce the impact of other factors on the operation of the rotor. In addition, from a large number of theoretical studies on rotor rubbing, most of them use a rigidly supported single-disc rotor model, and the experimental bench is designed as a single-disc rotor system supported by sliding bearings.

The detailed panel of the mechanical vibration detector is shown in Figure 8.

In the process of rotor rubbing, different operating conditions and degree of rubbing will lead to different forms such as single-point local rubbing, multi-point local rubbing and whole-circle rubbing; Experimental device; friction-resistant copper rods are used for the rubbing stator part to ensure that the rotor is not damaged; the copper rods are fixed on the bracket through threaded holes, so as to adjust the gap between the rotor and the stator through threaded connections to simulate different degrees of rubbing ; The rubbing end of the copper rod and the rotor is processed into a spherical surface to ensure that the two are rubbed at a single point; in order to protect the rotating shaft, the rubbing position is selected on the disc; during the experiment, an eddy current sensor needs to be used to obtain the vibration signal of the disc , because the design of the experimental bench is relatively compact, in order to make full use of the space, the sensor bracket and the rubbing device are designed as a whole, as shown in Figure 9.

The invention introduces the detection device technology into the rotating machinery fault detection system, uses the software and the eddy current sensor as the software and hardware platform to detect the rotating machinery vibration signal. Through the use of the detection device, the accuracy of fault diagnosis is improved; therefore, the rotating machinery fault detection system of the detection device is added. Compared with the traditional test instrument, the test High precision.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Technical personnel, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical content disclosed above, but any content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (6)

1. A fault diagnosis and testing system for rotating machinery, which is an experimental bench for a single-disc rotor system supported by sliding bearings. The experimental bench is composed of a mounting plate, a motor, a single-disc rotor, a sliding bearing, and a grinding device. The motor is mounted on the mounting plate, the sliding bearings are arranged on both ends of the single disc rotor, the sliding bearings are mounted on the mounting plate through the bearing seat, and one end of the single disc rotor is connected with the motor output shaft, so that the motor output shaft, the single disc rotor are connected to the motor output shaft. The rotating shaft and the sliding bearing of the disc rotor are located on the same axis, and the rubbing device is arranged around the single disc rotor. Eddy sensor, data acquisition card and computer, the X-direction eddy sensor and Y-direction eddy sensor are respectively arranged on one side of the single disc rotor, so that the X-direction eddy sensor and the Y-direction eddy sensor on the same plane perpendicular to each other, the X-direction eddy sensor and the Y-direction eddy sensor are connected to the data acquisition card, and the data acquisition card and the computer are communicated with each other; the contact between the rubbing device and the single disc rotor forms mutual resistance to change the X direction For the signals collected by the eddy sensor and the Y-direction eddy sensor, the computer is provided with virtual simulator software to process and analyze the data sent by the data acquisition card. 2 . The fault diagnosis and testing system for rotating machinery according to claim 1 , wherein the friction device is composed of bolts and a fixing seat, and the fixing seat is mounted on the mounting plate and is located on the single-disc rotor. 3 . On one side, the fixing seat is provided with a through hole, and the bolt is installed in the through hole, so that the direction of the bolt coincides with the axis of the single-disk rotor. 3. a kind of working method of a kind of rotating machinery fault diagnosis and testing system according to claim 1, is characterized in that: its working method is according to the software in technical machine, is specifically as follows: software design is by using LabVIEW programming language in Windows XP system On the software platform, set the parameters on the front panel to control the data acquisition card for data acquisition, analyze and process the acquired data through the software system, and use the AI Acquire Waveforms function in the program to collect the incoming data from two sensors at the same time. The Array function introduces two signals respectively; after the signals are filtered, the signals in the horizontal and vertical directions are respectively sent to the Graph control to display the waveform diagram, and the signals in the two directions are superimposed on an XY Graph control to display the The shaft center trajectory diagram of the rotor is obtained; and the LabVIEW software is used to analyze the waveform characteristics of the signal in the time domain and frequency domain, thereby identifying and diagnosing the rubbing fault of the rotating machinery, mainly for the single-disc rotor rubbing vibration signal. The rub-impact fault is identified and diagnosed by the time-domain waveform characteristics, the single-disc rotor axis motion trajectory parameters and the vibration spectrum during rubbing vibration. 4. The working method of a rotating machinery fault diagnosis and testing system according to claim 3, wherein the time-domain waveform is a relationship curve of the vibration parameter changing with time, and when the rotating machinery is in normal operation, the The time domain waveform of the vibration signal is a smooth sine curve. The rotor vibration waveforms in the X and Y directions collected by the software in real time are shown in Figure 2. From the time domain waveforms, it can be judged that the rotor has undergone dynamic and static rubbing; the original X-axis and Y-axis directions are The high-frequency components are superimposed on the sinusoidal signal, and the waveform is unstable. The vibration waveform in the Y-axis direction has obvious clipping and the waveform is distorted, indicating that the dynamic and static rubbing of the rotor is more serious, especially the rotor rubbing in the Y-axis direction. The displacement of the rotor is limited by the rubbing in this direction, so the "peak" of the vibration waveform disappears and becomes more "flat"; the signs indicate that the single-disc rotor has entered the middle stage of wear; in order to explore the cause of the rubbing failure of the rotor, At the same time, the motion trajectory parameters of the single-disk rotor shaft center during rubbing vibration are collected, and the time-domain waveform characteristics are comprehensively analyzed. 5. The working method of a rotating machinery fault diagnosis and testing system according to claim 3 or 4, characterized in that: the single-disc rotor axis motion track parameters during said collection of rubbing vibration are as follows: a. Trajectory characteristics of rotor axis The shaft center trajectory is obtained by using the X-direction eddy sensor and the Y-direction eddy sensor that are perpendicular to each other in the same plane of the rotating shaft to collect data at the same time. Draw a graph for the abscissa and the Y direction data as the ordinate; The reasons for the whirl motion of the single-disc rotor may be rotor unbalance, poor alignment, and static and dynamic rubbing; the whirl trajectories caused by different reasons are not the same, which also shows that different rotor shafts are relative to the bearing seat. Motion trajectory; when the rotating machinery is in normal operation, the time-domain waveform of the vibration signal is a sine curve; the mathematical expression of two mutually perpendicular sine signals is x(t)=A _x cos(ω _x t+φ _x )=A _x cos(2πf _x t+φ _x ) (1) y(t)=A _y cos(ω _y t+φ _y )=A _y cos(2πf _y t+φ _y ) (2) When the frequencies of the two sinusoidal periodic signals are the same, that is, f _x =f _y , the trajectory is generally an ellipse;

Apply XY Graph on the software platform to display the Lissajous graph to measure the rotor axis trajectory, and judge the rotor running state and fault state from this; The sine law changes, among which, assuming that the number of data points, amplitude and frequency are the same, when the phase difference between them is equal to 90°, it is a circle. It can be seen that if the rotor has no rubbing fault, under ideal conditions, The running track of the shaft center should be a circle; if A _x ≠ A _y , that is, when the amplitudes of the rotor in the x and y directions are not equal, the displayed figure is an ellipse; When a vibration fault occurs in a rotating machine, the time domain waveform is distorted instead of a sinusoid, so the axis motion trajectory is not circular; The analysis is carried out through some typical trajectory patterns of the single-disc rotor running under different fault conditions, the experimentally measured rotor axis running trajectory patterns after wavelet packet de-noising, and the fault symptom table mapped by the typical trajectory of the single-disc rotor axis. , and then according to the time domain waveform of the rotor vibration, it has been judged that the rotor has a serious rubbing fault, and the axis running track shows the cause of the fault; according to the D'Alembert's principle, the rotor axis motion equation caused by the rotor unbalance is:

where m is the mass of the rotor, c is the internal and external damping coefficient when the rotor rotates, k is the bending stiffness of the shaft, ζ is the eccentricity of the rotor, and ω is the angular velocity of the rotor rotating; b. Measurement of radial displacement of rotor shaft The radial vibration displacement value of the shaft center of the single-disk rotor is the most intuitive digital quantity to judge the severity of the rotor rubbing fault; when the running rotor vibrates radially, the distance between its surface and the eddy current sensor changes with time, and the sensor The output voltage also changes accordingly; the LabVIEW program in the application software can measure the voltage value when the distance between the rotor surface is the smallest and the largest voltage value, and the peak-to-peak value is the voltage extreme value when the rotor vibrates radially, and its corresponding Non-electricity is the maximum radial displacement of the shaft center; when the running rotor has radial rubbing vibration, the output voltage of the eddy current sensor changes in direct proportion to the distance between the plane coil and the rotor; Use Amplitude and levels.vi of LabVIEW in the software to detect the output voltage when the plane coil of the eddy current sensor is farthest from the rotor, display the voltage value of the experimental data, and the experimental data when the distance is the closest is the voltage value, peak-to-peak voltage value; The peak-to-peak value is the maximum voltage output change of the eddy current sensor. Using the measured data of the standard linear segment of the eddy current sensor calibration and the Linear Fit.vi of LabVIEW, the least squares fitting linear equation is obtained as y=6.11+0.91x (5) From this, the slope is 0.91, which is also the sensitivity of the eddy current sensor, and its mathematical expression is

where △y is the sensor voltage output increment, △x is the rotor vibration displacement; Using the formula (6), the corresponding maximum radial displacement of the shaft center can be obtained, which is enough to explain the severity of the rotor rubbing failure. 6. The working method of a rotating machinery fault diagnosis and testing system according to claim 3, wherein the rotor vibration spectrum analysis is as follows: In order to accurately judge the fault vibration frequency, the detection signal is further analyzed in the frequency domain. In most cases, the rotating machinery vibration signal is a complex signal superimposed by a variety of excitation signals, which can be decomposed into a series of harmonic components. The component represents the response of the corresponding frequency excitation in the linear system, and each harmonic component contains the amplitude and phase characteristic quantities; Using the spectrum analysis program designed by LabVIEW, in order to reduce the leakage effect, before the Fourier transform of the rotor vibration signal, the window function is used to weight it, and the actual vibration spectrum analysis diagram is analyzed, and it can be clearly seen that the fundamental frequency is the rotor's The rotational frequency is exactly the same as the set rotational speed; there is a peak at twice the fundamental frequency, which is one of the important characteristic signals of rotor rubbing, indicating that the axial vibration of the rotor is stronger than the radial vibration, which is in line with the comprehensive rubbing vibration fault. Characteristics.

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