Summary of the invention
The purpose of this invention is to provide a kind of rotating machinery transient signal analytical approach, be intended to remedy the existing infull limitation of transient signal analytical approach information representation, this method is convenient to identification equipment inherent characteristic parameter, and a kind of effective means of fault analysis and diagnosis of equipment is provided.
A kind of analytical method of rotor transient signal of the present invention, the step of this method is as follows:
1) arranges two mutually perpendicular eddy current displacement sensors in the rotor cross section, gather the vibration signal of rotor with respect to bearing seat, sensor orientation should be consistent with the rotor rotation direction to the direction of Y by X, and employing waits the tach signal collection also to carry out integer-period sampled synchronously with key signal;
2) signal of gathering is carried out anti-aliasing filtering, low-pass filtering etc., remove unnecessary interfering noise signal;
3) lead the arrow that shakes, the arrow ratio that shakes, the arrow angle that shakes, arrow phase calculation, adopt FFT conversion again, utilize a FFT calculating to obtain these characteristic parameters simultaneously;
4) draw the graph of a relation of each parameter with respect to rotating speed;
5) vow that with main shaking the measuring point oscillation intensity under the graph expression single-frequency changes, vow the ovality variation of representing measuring point single-frequency whirling motion track than figure with shaking, vow that with shaking angle figure represents the variation of maximum vibration direction, represents the variation of vibration vector and fixed phase point with the arrow phase diagram.
Main shaking vowed the major semi-axis that is used for representing ellipse; equal positive precession radius of circle and anti-precession radius of circle sum; main shaking vowed the intensity of expression single-frequency lower rotor part vibratory response; during start and stop is analyzed; the main arrow figure that shakes is used for describing the single-frequency oscillation intensity with the change in rotational speed rule; vow that with load, flow, pressure and other parameters change curve, then the oscillation intensity of the main arrow figure descriptive system that shakes is with the Changing Pattern of load, flow, pressure and other parameters if be expressed as main shaking.
Shake and vow than equaling the merchant that pair is shaken and vowed and lead the arrow that shakes, be used for describing the ovality of single-frequency whirling motion track, its span is [1,1], vows that when shaking when being 0, the rotor eddy track deteriorates to straight line, the length of straight line is 2 times of the main arrow that shakes, vow that when shaking the rotor eddy track is a circle opposite with rotary speed direction than for-1 the time, when shaking arrow when being 1, the rotor eddy track is a circle identical with rotary speed direction, vow that when shaking numerical value is big more when being positioned between (0,1) than value, the expression ellipse approaches circle more, direction of motion is the forward whirling motion, vows when shaking when being positioned between (1,0) than value, absolute value is big more, the expression ellipse approaches circle more, and direction of motion is reverse whirling motion, and the arrow that shakes is used to be expressed as shaking vow that ratio is with rotating speed than figure, load, flow, the rule that pressure and other parameters changes.
Shake and vow that the angle represents that main shaking vow angle with the directions X sensor orientation, the maximum direction of representative vibration, shake and vow that the angle is only relevant with the inherent characteristic of system itself, with amplitude, the phase-independent of exciting force, the variation that following the tracks of shakes vows the angle is used to judge the variation of system's inherent characteristic.
Vow that phase place represents that main shaking vow angle with the fixed phase direction, vow that phase place was both relevant, also relevant with exciting force with system inherent characteristic own.
From the signal of two orthogonal passages, and main arrows that shake, shake and vow than, the relation between angle, arrow phase place and the single channel signal of vowing of shaking suc as formula shown in (1) (2):
In the formula, x, y are two single channel signals, and X, Y represent x respectively, the amplitude of y,
Expression x, the phasing degree of y, θ represents to shake and vows angle, Φ
αPhase place, R are vowed in expression
a, R
bMain arrows that shake of expression, pair arrows that shake, the v arrow of representing to shake compares.
Multiple FFT method is adopted in the main arrow that shakes, the calculating of shaking and vowing ratio, shaking and vow the angle, vow phase place.
Each parameter is an X-Y scheme with respect to rotating speed, and horizontal ordinate is a rotating speed, the master that ordinate is respectively single-frequency shake arrow, shake vow than, shake and vow the angle and vow phase place.
Each parameter is a three-dimensional plot with respect to rotating speed, and the X coordinate is rotating speed or frequency, and the Y coordinate is frequency or rotating speed, the Z coordinate is respectively main arrows that shake, shake vow than, shake and vow angle and arrow phase place.
Embodiment
Complete vowing that spectrogram comprises four width of cloth figure in fact altogether, the promptly main arrow figure that shakes, shake and vow than figure, shake and vow angle figure, vow phase diagram, is example with regard to the vibration of single-frequency respectively below, and the physical significance of each parameter is described.
If the equation of motion with the disc centre of Ω angular velocity rotation can be expressed as:
In the formula, X, Y,
Be respectively x, the amplitude of y direction, first phase parallactic angle.
Running orbit by the disc centre of formula (1) expression is an ellipse.Complete each parameter of spectrogram and the X of vowing, Y,
Between relation can be expressed as formula (2)
In the formula, V
mBe the main arrow that shakes, V
sBe the pair arrow that shakes, ρ is the arrow ratio that shakes, and θ shakes to vow angle, φ
aFor vowing phase place.
According to the rotor dynamics theory, the response for unbalance mass, produces has
In the formula, mr is a mass-radius product, k
x, k
y, c
x, c
yBe respectively x, the stiffness coefficient of y direction and ratio of damping, M are rotor quality, and α is the unbalance mass, phasing degree, λ
x, λ
y, ξ
x, ξ
yBe respectively x, the frequency ratio of y direction and damping ratio.If order
Then have
If make β=Y/X, then have:
Contact formula (3), (4), can release as drawing a conclusion:
(1) regularly at rotating speed one, x, the amplitude ratio of y direction and phase differential, promptly
Only with the intrinsic parameter k of system itself
x, k
y, c
x, c
y, M is relevant, and with amplitude of exciting force and phase-independent;
(2) vow that the angle is only relevant with amplitude ratio and phase differential owing to shake, therefore shake vow the angle also with amplitude of exciting force and phase-independent;
(3) vow that ratio is only relevant with amplitude ratio and phase differential owing to shake, therefore shake vow than also with amplitude of exciting force and phase-independent, the span of vowing ratio of shaking is [1,1], when value is 1, the movement locus of expression rotor axis is the circle of forward whirling motion, and when value was-1, the movement locus of expression rotor axis was the circle of reverse whirling motion, when value is (1, during any value 1), the movement locus of expression rotor axis is the ellipse of a whirling motion forward or backwards, and the size of absolute value is represented ovality;
(4) since main shaking vow and represent the elliptical orbit major semi-axis, the therefore main arrow that shakes has been described the intensity of vibratory response, it not only with the intrinsic relating to parameters of system, and relevant with amplitude of exciting force, but with the exciting force phase-independent;
What (5) vow that phase place describes is the main phasing degree that shakes and vow, so its expression is the phase differential of vibratory response maximal value and reference point, not only with the intrinsic relating to parameters of system, and also relevant with the phase place of exciting force, but have nothing to do with amplitude of exciting force;
In sum, the present invention compares with existing transient signal analytical approach, has following advantage:
(1) according to the main arrow figure that shakes, can follow the tracks of the variation of oscillation intensity reliably, remedy the incomplete shortcoming of single channel information in the past;
(2) because shake vow the angle and shake vow than all only with system's self character relating to parameters, therefore shake and vow the angle and shake and vow the situation of change of ratio that can understand the inherent characteristic of system itself well, this is that analytical approach was not available in the past by tracking;
(3) under the constant situation of systematic parameter,, can understand the situation of change of exciting force preferably by following the tracks of the situation of change of main arrows that shake, arrow phase place;
(4) this method can provide than the information reliably more comprehensively of transient state analyzing method in the past for rotary machinery fault diagnosis and control aspect.
This method both can be used for analyzing rotating machinery start and stop process; also can describe and lead the arrow that shakes, shake and vow the situation that the arrow angle of comparing, shake, phasing degree change with other process parameter change; this method has identical processing procedure for these various process signals; therefore, be used for the implementation procedure that the start and stop analysis is the example process in detail with regard to this method below.
Rotating machinery is along with the response of the change procedure of some technological parameter and operational factor is one group of complete process signal, and it carries out fault diagnosis and parameter recognition etc. and have important value for the stability of analytical equipment.By the analysis of one group of process signal, can analyze the vibration characteristics of rotor, the reason of inquiry amplitude and phase change, obtain the key parameters such as critical rotary speed of unit actual motion, determine the unbalance response of rotor, the resonance of research structure and element etc. are one of important evidence of fault diagnosis.Be among the present invention on the basis of vowing spectral analysis technology (vector spectrum), systematically analyze full arrow spectrum parameter and rotor-support-foundation system parameter, the relation of exciting force parameter, proposed to be used for a kind of new method that rotating machinery process signal (transient signal) is analyzed---vow spectrogram entirely, and the advantage of the existing rotating machinery transient signal analytical approach of absorption, two kinds of representations---the two-dimensional representation method and the three-dimensional representation of full arrow spectrogram have been provided, the two-dimensional representation method is to use for reference the method for expressing of Bode diagram (Bode), be used to follow the tracks of the variation that single-frequency is vowed the spectrum correlation parameter entirely, resolution height; Three-dimensional representation is a method for expressing of using for reference the three-dimensional spectrum system of battle formations and cascade graphs, be used to follow the tracks of full variation of vowing the spectrum correlation parameter under the full rate, be panorama sketch, have the comprehensive advantage of information, the different method for expressing that in practicality, should use according to the different mining of application target.
Open machine data below in conjunction with one group that gathers on the experiment table shown in Figure 2 and specify this method application, this tests used sensor is non-contact electric eddy shift sensor, and transducer arrangements is a horizontal direction, and a vertical direction is mutually 90 degree.Experimental result such as Fig. 3 are shown in 4.
(1) frequency content analysis.By the three dimensional representation form of full arrow spectrogram, can see at an easy rate that in whole boosting velocity procedure the frequency content of rotor oscillation in this example, has only a frequency multiplication to exist;
(2) Analysis on Critical Rotating.All can carry out the analysis of critical rotary speed by X-Y scheme or three-dimensional plot, but more directly perceived by the X-Y scheme of observing 1X, accurately.The judgement of critical rotary speed, in the present invention, be to vow that by the main resultant of shaking phase place carries out, when rotor during near critical rotary speed, main shaking vows that amplitude increases rapidly, the place reaches maximal value in critical rotary speed, away from reducing rapidly after the critical rotary speed, and vow that phase place approaches 0 degree at the critical rotary speed place, and in critical rotary speed both sides reversion, in this example, can judge that by the main resultant arrow phase place of shaking critical rotary speed is 3520r/min;
(3) the rotor-support-foundation system self character is analyzed.In the present invention, mainly vow than analyzing with shaking by the shaking arrow angle in X-Y scheme or the three-dimensional plot, the characterisitic parameter of rotor-support-foundation system itself mainly contains rigidity, damping, in this example, when rotating speed is 1000-3000r/min, shake and vow that the angle is more steady, almost do not change, vow that the ratio variation is also less and shake, therefore we can say that rotor-support-foundation system itself is more stable, rigidity, damping change is little, when 1000r/min is following, shake and vow the angle and shake arrow than fluctuation is in a small amount all arranged, when being illustrated in the slow-speed of revolution, this forms bad total rigidity that causes owing to oil film, damping has fluctuation, when near one critical or one critical when above, shake and vows the angle and shake and vow than obvious variation is all arranged along with the rising of rotating speed, present periodically variable characteristics, this shows the maximum direction of vibration in continuous variation, and ovality is also in continuous variation, from the speed of the two variation, wanting that the maximum vibration direction changes is fast, and relative change slower of ovality;
(4) identification of maximum vibration direction.For condition monitoring for rotating machinery, the maximum vibration direction is most important, particularly for those units of estimating based on single channel signal, if transducer arrangements is not the maximum direction of vibration, just the running status of unit reality can't be accurately grasped probably, thereby some contingent accidents can't be in time avoided.In the present invention, shake by tracking and vow that the angle is easy to judge the maximum direction of vibration;
(5) tracking of ovality.Ovality is represented the difference of system performance on the one hand, on the other hand for some fault diagnosis (such as the rigidity on direction significantly reduces or a direction on acting on bigger power) have a very big use.About the tracking of ovality, vow by shaking in the present invention than realizing, if the absolute value of the arrow ratio that shakes is too little, represent that then ellipse is very flat, on the contrary then round; In this example, one critical when following, ellipse is round, and more stable, and one critical when above, along with change in rotational speed, when oval and bowlder and flat;
(6) identification of orbit of shaft center precession direction.The difference that the difference of orbit of shaft center precession direction is often indicating working state of system has the feature of anti-precession for the minority fault.Vow the tracking of ratio by shaking, can identify the precession direction easily, and not need key signal that in this example, shake and vow ratio all greater than 0, illustrating does not have anti-precession to take place.