CN101556200B - Vector spectrum based dynamic balance method for flexible rotor - Google Patents

Abstract

The invention discloses a vector spectrum based dynamic balance method for flexible rotors. Imbalance failure of the rotors on site can be truly and objectively found by a vector spectrum analysis software, the power-frequency principal vibration vector of the rotors on vibration measuring sections can be extracted by vector spectrum filtering method by measuring the original vibration signals of two mutually perpendicular channels on the vibration measuring sections; the principal vibration vector is used as the substitute of the amplitude and the phase of the power frequency of the rotors extracted in traditional single-channel signals; on-site dynamic balance is conducted by combing with influence coefficient method, and the balance process is less dependent on the experience and knowledge of operators, can greatly improve the efficiency and accuracy of the flexible rotor dynamic balance and is a highly integrated computer-assisted on-site dynamic balance method.

Description

Flexible rotor dynamic balance method based on full arrow spectrum

Technical field

Patent of the present invention belongs to rotor dynamic balance technology field, particularly, relates to rotary machinery fault diagnosis and vibration control field.

Background technology

At present, the flex rotor spot dynamic balance method is a lot, roughly be classified as two big classes, be method of model balancing and influence coefficient method, the principle that method of model balancing is based on counterweight group and principal mode quadrature is carried out the difference balance of each first order mode, it has adjustment of balance precision height, characteristics such as test number (TN) is few, yet, method of model balancing requires at first to obtain each first order mode data of rotor, simultaneously this method requires the operator to have rich experience knowledge, and adopts area of computer aided to carry out balance work not quite easily, is very restricted in actual applications.And the less experimental knowledge that depends on the operator of influence coefficient method, whole operation is finished by testing, and can adopt area of computer aided and robotization, thereby popular in many occasions.And the shortcoming of influence coefficient method is that it is not high for the sensitivity of the high order mode of rotor, the levels of precision of the main dependence of the calculating of influence coefficient and vibration amplitude and phase measurement, in case the precision degree descends, and may cause its calculation correction amount very big, so that the scene can't be implemented.Therefore, the measurements and calculations precision, particularly vibration amplitude of all kinds of balance parameters and phase information accurately obtain balance mass particularly important.But in the real balance, because the generation and the transmission link of balance error are more, and wayward, a spot of initial error may produce bigger balance error through accumulating finally, thereby causes the balance failure.

Summary of the invention

Patent purpose of the present invention is to provide a kind of flexible rotor dynamic balance method based on full arrow spectrum, this method can be found on-the-spot rotor unbalance fault by the full spectral analysis method objective reality ground of vowing, by measuring the vibration original signal of mutually perpendicular two passages on each vibration measuring cross section, carry out spot dynamic balance in conjunction with influence coefficient method, significantly improve the efficient and the precision of flexible rotor dynamic balance

In order to realize above purpose, technical scheme of the present invention is: a kind of flexible rotor dynamic balance method based on full arrow spectrum, and the step of this method is as follows:

1) discern rotor and whether have imbalance fault according to the full master who the vows spectrum arrow figure that shakes, the binary channels current vortex signal according to collecting on unit upper rotor part one end section carries out the vector analysis of spectrum, the direct rotor unbalance fault of this rotor of judgement from analyze collection of illustrative plates; Method of discrimination is: can find a highest spectral line of amplitude from the master of vector spectrum shakes arrow figure, as this spectral line is 1 frequency multiplication of rotor and apparently higher than other spectral line, exceed standard with reference to its value of shaking of international vibration standard, it is very big that then unbalanced possibility takes place rotor, judge from the other end of rotor then, if situation is similar, then decidable is the imbalance fault of rotor, needs to implement on-the-spot rotor dynamic balancing;

2) choose at least two according to the structure of rotor and increase the weight of the plane; During field balancing, determine to increase the weight of the number on plane and the position of increasing the weight of according to counterbalance effect and physical condition.

3) placement sensor, number of sensors is at least 2 times that increase the weight of number of planes, at least arrange a pair of vibration transducer in the every side of rotor, every pair of vibration transducer vertically is positioned over the axis of rotor rotation outside surface nearby mutually, be used to measure left and right bearing neighbouring level and vertical vibration, also have a key phase sensor to be positioned over the excircle place that one of them increases the weight of the plane in addition, be used for measuring of key signal;

4) increase the weight of to propose respectively on the plane at each and increase the weight of radius, and add a test mass, the machine of opening rises to the setting rotating speed, and records the corresponding master arrow that shakes;

5) each main shaking is vowed that utilizing influence coefficient method to calculate should respectively increase the weight of the counterweight that the plane adds respectively.

Further, this method also has the step of balance checking.

Further, if still exist uneven, repeating step 4), 5) and balance verification step, up to standard until balance.

Generally speaking, sensor is arranged symmetrically in the two ends of rotor, and two dynamically balanced sensors of plane rotor that increase the weight of are used to measure left and right bearing neighbouring level and vertical vibration for vertically being positioned over two ends of rotor rotation axis outside surface mutually nearby.

Vibration transducer adopts photoelectric sensor or current vortex sensor to measure the rotating speed of machine rotors and obtain the pulse signal of vibration phase reference, and for photoelectric sensor, requirement mark on axle is stained with the reflection arrowband, and remainder is the black area, and is perhaps opposite; For current vortex sensor, then require axle to go up the mark line place and drive a keyway, above sensor signal lines is linked to each other with dynamic balance instrument.

For the rotor that has two to increase the weight of the plane, balance method is as follows:

A) start the machine, promote rotating speed, start the initial vibration that dynamic balance instrument measures two planes, and the initial power frequency master who adopts the vector filtering algorithm directly to calculate two planes arrow that shakes;

B) increase the weight of the plane for two, set and increase the weight of radius, add a test mass Q in a plane therein ₁, Q ₁Be vector, its quality is q ₁, the position angle of reference marker on the relative rotor, reverse rotational direction is calculated as The machine of opening rises to same rotating speed, and records the corresponding master arrow that shakes;

C) take Q away ₁, on another plane, add test mass Q ₂, can record its corresponding main arrow that shakes;

D) utilize influence coefficient method can calculate the counterweight that should add on two planes respectively.

Patent of the present invention has following function and characteristics:

1, this method provides vector analysis of spectrum software and corresponding collection of illustrative plates Presentation Function, and vector spectrum has high resolving power, merges the characteristics of twin-channel signal, has special advantages for the identification of the imbalance fault of on-the-spot rotor.

2, vibration-measuring sensor adopts single cross section binary channels and becomes 90 arrangements of spending, and sensor is that non-contact electric eddy shift sensor is surveyed shaft vibration.Signals collecting adopts synchronous complete cycle of mode, can use the key signal triggering collection, also can adopt optoelectronic switch to trigger.

The power frequency master that employing is extracted each vibration measuring plane based on the software filtering mode of the vowing spectrum arrow that shakes, filtering method is by the fast algorithm of multiple FFT, synchronously complete cycle signals collecting characteristics, the precision and the efficient of power frequency amplitude and phase extraction have been improved, avoid the one-sidedness of single channel signal preferably, thereby improved the balance quality of influence coefficient method.

3, vibration measuring number of planes can be specified arbitrarily, satisfies the requirement for dynamic balance of most flexible rotor shaft systems fully.

4, equilibrium process adopts area of computer aided to carry out, and operation is directly perceived, understands, less depends on expertise.

Description of drawings

Fig. 1 is on-the-spot measuring point arrangement;

Fig. 2 is the vector spectrogram;

Fig. 3 is for vowing the process flow diagram of spectral filter.

The embodiment of patent of the present invention is:

(1) based on the rotor unbalance Fault Identification of vowing spectrum

Embodiment

Binary channels current vortex signal according to collecting on the unit upper rotor part one end cross section carries out the vector analysis of spectrum, can judge directly from collection of illustrative plates whether this rotor belongs to the rotor unbalance fault.Method of discrimination is: can find a highest spectral line of amplitude from the master of vector spectrum shakes arrow figure, as this spectral line is 1 frequency multiplication of rotor and apparently higher than in other spectral line, exceed standard with reference to certain its value of shaking of international vibration standard, it is very big that then unbalanced possibility takes place rotor, judge from the other end of rotor then, if situation is similar, then basic decidable is the imbalance fault of rotor, needs to implement on-the-spot rotor dynamic balancing.

Referring to Fig. 2, is from certain CO with vector spectrogram identification rotor unbalance fault method among the figure ₂Compressor train is on-the-spot near the one group vibration data of pressurizing tank cross section by a pair of mutually perpendicular current vortex sensor x and y actual measurement, and to x, the y direction is made spectrogram and principal oscillation polar plot separately.If separately from the amplitude image of x direction this unit 2 frequency multiplication maximums as can be seen, most possibly be that the rotor misalignment phenomenon has taken place, but see unit 1 frequency multiplication maximum from the y direction, obviously greater than 2 frequencys multiplication, the unit fault should be an imbalance fault, promptly use separately x, contradiction has appearred in y direction judgement unit fault, and this is that the one-sidedness of single channel signal causes the problem that occurs.And principal oscillation arrow figure combines x, y both direction signal and the amplitude image that obtains has objective reality and uniqueness, shaking from the master of these group data, 1 frequency multiplication amplitude of unit is obvious as can be seen the arrow figure, and 2 frequencys multiplication are less, and therefore the rotor unbalance fault has taken place unit certainly.

(2) increase the weight of determining of plane

During field balancing, generally determine to increase the weight of the number on plane and the position of increasing the weight of according to counterbalance effect and physical condition.

(3) layout of sensor

The method for arranging of sensor can carry out according to the characteristics of rotor, and number of sensors is at least 2 times that increase the weight of number of planes.Sensor often adopts the two ends that are arranged symmetrically in rotor, the sensor arrangement of biplane rotor dynamic balancing is seen shown in Figure 1, adopt 5 current vortex sensors altogether, key phase sensor KP is used for measuring of key signal, 1X, 1Y, 2X, 2Y are respectively applied near left and right bearing the level and vertical vibration of measuring.

(4) transient equilibrium process

Below be that example illustrates that use realizes the process of balance based on the spot dynamic balance instrument of full arrow spectrum with the biplane, the balance of flex rotor generally need be carried out multilevel balance under a plurality of rotating speeds from low to high, here with a certain rotation speed n (rev/min) under equilibrium process be example explanation (equilibrium process under other rotating speed is similar with it):

A) selected two vibration measuring planes 1 and plane 2 on machine are mutually 90 ° of directions two current vortex sensors respectively are installed on each plane, adopt photoelectric sensor or current vortex sensor to measure the rotating speed of machine and obtain the pulse signal of vibration phase reference.If photoelectric sensor, requirement mark on axle is stained with a reflection arrowband, and remainder is the black area, and is perhaps opposite.If the use current vortex sensor then requires axle to go up the keyway that the mark line place opens more than one millimeters deep.Above 5 sensor signal lines are linked to each other with dynamic balance instrument.

B) start the machine, raising speed starts equilibristat and measures the x on two planes and the initial vibration of y direction respectively to rotation speed n rev/min, and the initial power frequency master who adopts the vector filtering algorithm directly to calculate plane 1 and plane 2 shakes and vows V ₁₀And V ₂₀Power frequency master shakes and vows calculating principle as shown in Figure 3.Shake with the master on wherein plane 1 and to vow V ₁₀Be calculated as example:

If X that records on the plane 1 and Y direction vibration original signal are respectively { x _iAnd { y _i(i=0,1,2 ..., N-1), N is that the collection of signal is counted, and is generally 2 integral number power, as 512,1024, and 2048 etc., R is phase sampling number weekly, is generally 32,64 etc.Construct complex signal z then _i=x _i+ jy _i(i=0,1,2 ..., N-1), and adopt formula (1) that the structure signal is carried out multiple FFT conversion:

$Z_n=\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{z}_k{e}^{-j2\mathrm{\πk}/N}$ (n＝0，1，2，···N-1) (1)

Then, calculating the power frequency master shakes and vows the sequence number Ind of spectrum:

Ind＝N/R-1 (2)

Shake arrow (comprising amplitude and position angle) available formula (3), (4) of power frequency master calculates:

$R_{\mathrm{ai}}=(\sqrt{Z_{\mathrm{Ii}}^2+Z_{\mathrm{Ri}}^2}+\sqrt{Z_{\mathrm{Ri}}^2+Z_{I(N-i)}^2})/2N$ (i＝Ind) (3)

${\mathrm{\α}}_i=\arctan \left(\frac{Z_{\mathrm{Ri}}{Z}_{\mathrm{Ii}}+Z_{I(N-i)}{Z}_{R(N-i)}}{Z_{\mathrm{Ri}}{Z}_{R(N-i)}-Z_{\mathrm{Ii}}{Z}_{I(N-i)}}\right)$ (i＝Ind) (4)

Then the initial power frequency master of planar I shakes and vows V ₁₀=R _AInd∠ α _Ind

C) choose two according to the structure of rotor and increase the weight of plane 1 and plane 2, increase the weight of radius and be respectively r ₁And r ₂, in plane 1, add earlier a test mass Q ₁, (Q ₁Be vector, its quality is q ₁, the position angle of reference marker on the relative rotor, the reverse rotational direction angle is

), same, the machine of opening rises to same rotating speed, and records corresponding master and shake and vow and be V ₁₁And V ₂₁

Can calculate influence coefficient (position angle is the effect vector of the unit test mass of zero degree) α this moment ₁And β ₁:

${\mathrm{\α}}_1=\frac{V_{11}-V_{10}}{Q_1}---\left(5\right)$

${\mathrm{\β}}_1=\frac{V_{21}-V_{20}}{Q_1}---\left(6\right)$

D) take Q away ₁, on plane 2, add test mass Q ₂, can record V ₁₂And V ₂₂

In like manner can calculate α ₂And β ₂:

${\mathrm{\α}}_2=\frac{V_{12}-V_{10}}{Q_2}---\left(7\right)$

${\mathrm{\β}}_2=\frac{V_{22}-V_{20}}{Q_2}---\left(8\right)$

E) utilize influence coefficient method can calculate should be respectively on the plane 1 and the counterweight that adds of plane 2 be P ₁(size and Orientation that comprises counterweight, the definition of positive dirction with add test mass Q ₁And Q ₂Identical) and P ₂Calculate P ₁And P ₂Method separate vector equation group (9) exactly:

$\left\{\begin{array}{c}{\mathrm{\&alpha;}}_1{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="H2009101432247E00021.png"\; state="\{\{state\}\}">P</figure-callout>}}_1+{\mathrm{\&alpha;}}_2{P}_2=-V_{10}\\ {\mathrm{\&beta;}}_1{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="H2009101432247E00021.png"\; state="\{\{state\}\}">P</figure-callout>}}_1+{\mathrm{\&beta;}}_2{P}_2=-V_{20}\end{array}\right.---\left(9\right)$

F) add counterweight according to (e) step result of calculation, the machine of opening rises to same rotating speed, measurement residual vibration vector V ' ₁And V ' ₂, as V ' ₁And V ' ₂With respect to the initial vibration vector V ₁₀And V ₂₀Its amplitude all has significantly and reduces, and illustrates that counterbalance effect is better.

(5) balance checking and conclusion

In order to verify the dynamically balanced counterbalance effect of full arrow, carried out a large amount of checking work at the rotor test platform, experimentation launches according to above implementation step.Experiment will be vowed dynamic balance method and traditional comparing based on the dynamic balance method of folk prescription to sensor signal entirely, and experimental data be listed as shown in table 1.

Table 1 biplane experiment of dynamic balancing data (balancing speed: 2400 rev/mins)

Table 2 calculates and the balance checking

As can be seen from Table 2, it is slightly different with the counterweight of calculating with X or y direction sensor signal method separately that the need that calculate according to full arrow dynamic balance method add counterweight, in order to verify the precision of various dynamic balance methods, add counterweight according to 3 kinds of counterweight schemes respectively, and measure and add latter two plane of counterweight x, the vibration on the y direction.Can obtain by adding the data analysis of counterweight after vibration: adopt top two kinds (using X separately, the Y direction signal) balance method effects suitable substantially, last vibratory output is bigger than normal, and the occasion in that balance quality is had relatively high expectations then needs further balance toward contact.Vow vibratory output that dynamic balance method records at last at x entirely and adopt, all smaller on the y both direction, its counterbalance effect obviously is better than traditional based on the balance method of folk prescription to signal.

By comparative analysis as can be known, relative and classic method vows that full dynamic balance method has higher precision, can play to significantly improve counterbalance effect, reduces the purpose of balance number of times.

Claims (6)

1. flexible rotor dynamic balance method based on full arrow spectrum is characterized in that the step of this method is as follows:

1) discerns rotor and whether have imbalance fault according to the master of the vector spectrum arrow figure that shakes, according to the binary channels current vortex signal that collects on unit upper rotor part one end section, carry out the vector analysis of spectrum, from analyze collection of illustrative plates, directly judge the rotor unbalance fault of this rotor; Method of discrimination is: can find a highest spectral line of amplitude from the master of vector spectrum shakes arrow figure, as this spectral line is 1 frequency multiplication of rotor and apparently higher than other spectral line, exceed standard with reference to its value of shaking of international vibration standard, it is very big that then unbalanced possibility takes place rotor, judge from the other end of rotor then, if situation is similar, then decidable is the imbalance fault of rotor, needs to implement on-the-spot rotor dynamic balancing;

2) choose at least two according to the structure of rotor and increase the weight of the plane;

3) placement sensor, number of sensors is at least 2 times that increase the weight of number of planes, at least arrange a pair of vibration transducer in the every side of rotor, every pair of vibration transducer vertically is positioned over the axis of rotor rotation outside surface nearby mutually, be used to measure left and right bearing neighbouring level and vertical vibration, also have a key phase sensor to be positioned over the excircle place that one of them increases the weight of the plane in addition, be used for measuring of key signal;

4) increase the weight of to propose respectively on the plane at each and increase the weight of radius, and add a test mass, the machine of opening rises to the setting rotating speed, and records the corresponding master arrow that shakes;

5) each main shaking is vowed that utilizing influence coefficient method to calculate should respectively increase the weight of the counterweight that the plane adds respectively.

2. the flexible rotor dynamic balance method based on full arrow spectrum according to claim 1 is characterized in that this method also has the step of balance checking.

3. the flexible rotor dynamic balance method based on full arrow spectrum according to claim 2 is characterized in that, if still exist uneven, repeating step 4), 5) and balance verification step, up to standard until balance.

4. according to claim 1,2 or 3 described flexible rotor dynamic balance methods based on full arrow spectrum, it is characterized in that, vibration transducer is arranged symmetrically in the two ends of rotor, two dynamically balanced vibration transducers of plane rotor that increase the weight of are used to measure left and right bearing neighbouring level and vertical vibration for vertically being positioned over two ends of rotor rotation axis outside surface mutually nearby.

5. the flexible rotor dynamic balance method based on full arrow spectrum according to claim 4, it is characterized in that, key phase sensor adopts photoelectric sensor or current vortex sensor to measure the rotating speed of machine rotors and obtain the pulse signal of vibration phase reference, for photoelectric sensor, requirement mark on axle is stained with the reflection arrowband, remainder is the black area, and is perhaps opposite; For current vortex sensor, then require axle to go up the mark line place and drive a keyway, above sensor signal lines is linked to each other with dynamic balance instrument.

6. the flexible rotor dynamic balance method based on full arrow spectrum according to claim 5 is characterized in that for the rotor that has two to increase the weight of the plane, balance method is as follows:

A) start the machine, promote rotating speed, start the initial vibration that dynamic balance instrument measures two planes, and the initial power frequency master who adopts the vector filtering algorithm directly to calculate two planes arrow that shakes;

B) increase the weight of the plane for two, set and increase the weight of radius, add a test mass in a plane therein

,

Be vector, its quality is

, the position angle of reference marker on the relative rotor, the reverse rotational direction angle is

, the machine of opening rises to same rotating speed, and records the corresponding master arrow that shakes;

C) take away

, on another plane, add test mass

, can record its corresponding main arrow that shakes;

D) utilize influence coefficient method can calculate the counterweight that should add on two planes respectively.

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