CN105403364A - Dual-trail-weight balancing method of asymmetric rotor - Google Patents

Abstract

Provided in the invention is a dual-trail-weight balancing method of an asymmetric rotor. The method comprises the following steps: 1, measuring original vibration of two measurement points of a rotor; 2, selecting two trail weight points at different axial positions to carry out trail weight processing simultaneously and carrying out calculation to obtain influence coefficients of symmetric weighting and anti-symmetric weighting without considering phase characteristics of trail weight points; 3, selecting a second group of trail weight points at different positions and repeating the last step to obtain a second group of influence coefficients of symmetric weighting and anti-symmetric weighting; 4, carrying out calculation respectively according to the two symmetric weighting influence coefficients and two anti-symmetric weighting influence coefficients so as to obtain weighing values needed for eliminating original symmetric vibration and anti-symmetric vibration; and 5, carrying out vector synthesis on the symmetric weighting value and the anti-symmetric weighting value that are obtained by calculation to obtain a balance weight value of a cross section where each trial weight point is located, and carrying out weighting balancing. According to the invention, trail weighting is only carries out twice and balance weighting is only carries out once, so that the dynamic balancing process is realized rapidly with high efficiency. Direct operation can be carried out on the traditional high-speed dynamic balancing machine directly, so that the operation becomes simple and convenient.

Description

The two test mass balancing method of asymmetrical rotor

Technical field

The present invention is applied to the high-speed balancing of cross section asymmetrical rotor, and there is the horizontal screw centrifuge of groove at side surface in applicable field, has the transient equilibrium of the rotating machinery such as engine rotor, two blade propeller of line grain.

Background technology

Two cross section unequal rotors of the main moments of inertia are called asymmetrical rotor, and asymmetrical rotor is widely used in engineering, the horizontal screw centrifuge of such as groove at side surface, the engine rotor having line grain, two blade propeller etc.Due to the non-stiffness coefficient cyclical variation to becoming to have cited approvingly of rotating shaft, its vibration equation is different from symmetric rotor, is the second order differential equation with time-varying parameter, and the amount of unbalance at out of phase place, same cross section is different to the contribution of system vibration.Traditional dynamic balance method is mainly divided into influence coefficient method and harmonic component method two class, and one of necessary condition of these two kinds of methods is applicable to increasing the weight of of arbitrary phase position in this balance cross section for influence coefficient that a test mass of a certain phase position in balance cross section obtains.Unbalance response (comprising amplitude and the phase place) difference increased the weight of for out of phase due to asymmetrical rotor is very large, the influence coefficient obtained at the test mass of out of phase position, same cross section is not definite value, and the concept in the balance cross section therefore in traditional dynamic balance method is not suitable for asymmetrical rotor.In recent years, Chinese scholars pays close attention to several aspect such as asymmetrical rotor vibration characteristics, unstable vibration mechanism and vibration control method, asymmetric rotor Parametrical excitation characteristic always, still little for the dynamic balance method research with the cross section asymmetrical rotor that very strong engineer applied is worth.

Summary of the invention

Object of the present invention, for the transient equilibrium response characteristic of cross section asymmetrical rotor, provides a kind of scientific and effective two test mass balancing methods being applicable to asymmetrical rotor.

The technical scheme of invention is as follows:

The two test mass balancing method of asymmetrical rotor, comprises following steps, as shown in Figure 1:

1. measure the original vibration of rotor two measuring points;

2. choosing the test mass point test mass simultaneously of two axially different positions, calculating the influence coefficient that symmetry increases the weight of to increase the weight of with antisymmetry when not considering test mass point phase characteristic;

3. choose the test mass point that second group of position is different, repeat previous step, obtain second group of symmetry and increase the weight of to increase the weight of influence coefficient with antisymmetry;

4. increase the weight of influence coefficient according to two symmetries respectively and two antisymmetry increase the weight of influence coefficient, calculate to eliminate and add weight required for original symmetric vibration and antisymmetric vibration;

5. the symmetry calculated is added weight and antisymmetry to add weight and carry out Vector modulation, obtain the counterweight amount in cross section, each test mass point place, hamming.

The balance of described two measuring points at least needs four test mass points, carries out twice balance test mass, and the phase place often organizing test mass point preferably differs 90 °, and the phase place of second group of test mass point and first group of test mass point also differs 90 °.

Any one test mass point that first time increases the weight of can be positioned at same axial cross section with any one test mass point that increase the weight of for the second time.

Symmetry increases the weight of to increase the weight of the amount of unbalance that influence coefficient is only applicable to test mass point place with antisymmetry.

Be described as follows:

For engineering being applied two general measuring point transient equilibrium, the dynamic balance method process (amount of overstriking is vector) specific as follows that the present invention proposes:

1. paste reflective tape in rotor one end, the photoelectric sensor being used for measuring vibrations phase place is installed.Bearing seat installs and measures the photoelectric sensor of vibration, and each sensor connects rotor vialog;

2. measure 2 original vibration A ₀and B ₀, as shown in Figure 2, A ₀for original vibration, A ₁for the vibration after first time test mass, A ₂for the vibration after second time test mass, by that analogy, B in like manner, is decomposed into symmetrical components A _d0with antisymmetric component A _f0:

A _d0＝0.5(A ₀+B ₀)；(1)

A _f0＝0.5(A ₀-B ₀)。(2)

3. at selected test mass point P ₁, P ₂examination increases the weight of m respectively ₁and m ₂, be decomposed into symmetrical components m _d1with antisymmetric component m _f1:

m _d1＝0.5(m ₁+m ₂)；(3)

m _f1＝0.5(m ₁-m ₂)。(4)

4. measure the vibration A after increasing the weight of ₁and B ₁, and be decomposed into symmetrical components A _d1with antisymmetric component A _f1:

A _d1＝0.5(A ₁+B ₁)；(5)

A _f1＝0.5(A ₁-B ₁)。(6)

5. calculate the symmetrical influence coefficient increasing the weight of to increase the weight of with antisymmetry respectively:

${\mathrm{\α}}_{d1}=\frac{A_{d1}-A_{d0}}{\left|m_{d1}\right|};---\left(7\right)$

${\mathrm{\α}}_{f1}=\frac{A_{f1}-A_{f0}}{\left|m_{f1}\right|}.---\left(8\right)$

6. take off m ₁and m ₂, at test mass point P ₃, P ₄upper test mass m ₃and m ₄, repetitive process 2,3 and 4, obtains increasing the weight of influence coefficient α _d2and α _f2;

7. the influence coefficient that the symmetry obtained according to twice test mass increases the weight of to increase the weight of with antisymmetry, calculate respectively symmetrical increase the weight of to increase the weight of with antisymmetry counterweight amount:

α _d1Q _d1+α _d2Q _d2+A _d0＝0；(9)

α _f1Q _f1+α _f2Q _f2+A _f0＝0。(10)

8., by symmetrical components and antisymmetric component synthesis, obtain P ₁, P ₂, P ₃, P ₄the counterweight M of place section ₁, M ₂, M ₃, M ₄for:

$M_1=Q_{d1}\frac{m_{d1}}{\left|m_{d1}\right|}+Q_{f1}\frac{m_{f1}}{\left|m_{f1}\right|};---\left(11\right)$

$M_2=Q_{d1}\frac{m_{d1}}{\left|m_{d1}\right|}-Q_{f1}\frac{m_{f1}}{\left|m_{f1}\right|};---\left(12\right)$

$M_3=Q_{d2}\frac{m_{d2}}{\left|m_{d2}\right|}+Q_{f2}\frac{m_{f2}}{\left|m_{f2}\right|};---\left(13\right)$

$M_4=Q_{d2}\frac{m_{d2}}{\left|m_{d2}\right|}-Q_{f2}\frac{m_{f2}}{\left|m_{f2}\right|}.---\left(14\right)$

Effect of the present invention is:

1. the present invention only needs twice test mass counterweight, and transient equilibrium processing efficient is rapid;

Not only 2. the present invention does not need the equipment increasing, reduce measurement point but also do not need specialty, can on traditional high-speed dynamic balance machine direct control, simple and convenient;

3. the present invention is directed to the high-speed balancing method of asymmetrical rotor, effectively can reduce the vibration of rotor, thus improve the life-span of rotor, improve the security that machine runs.

Accompanying drawing explanation

Fig. 1 is the two test mass balancing method process flow diagram of asymmetrical rotor;

Fig. 2 is test mass point schematic diagram;

Fig. 3 is the asymmetric helical rotor structure figure of certain horizontal screw centrifuge groove at side surface;

Fig. 4 is the asymmetric helical rotor spot dynamic balance Test Drawing of certain horizontal screw centrifuge groove at side surface.

Embodiment

Embodiment 1

The dynamic balance method that this example utilizes the present invention to propose, for the asymmetric helical rotor of certain horizontal screw centrifuge groove at side surface, application business general finite element software ANSYS carries out transient equilibrium analogue simulation to it.The asymmetric helical rotor structure schematic diagram of this horizontal screw centrifuge groove at side surface as shown in Figure 3.During 3300rpm, the dynamically balanced detailed process of ANSYS software simulation is as follows:

1. provide the original vibration A of measuring point ₀=11.02 ∠ 146 μm pp ∠ ° and B ₀=9.02 ∠ 136 μm pp ∠ °;

2. calculate symmetrical components A according to (1) formula, (2) formula _d0=9.97 ∠ 142 μm pp ∠ ° and antisymmetric component A _f0=1.328 ∠ 182 μm pp ∠ °;

3. as shown in Figure 3, at selected test mass point P ₁, P ₂examination increases the weight of m respectively ₁=16.8 ∠ 30g ∠ ° and m ₂=16.8 ∠ 120g ∠ °, are decomposed into symmetrical components m according to (3) formula, (4) formula _d1=11.9 ∠ 75g ∠ ° and antisymmetric component m _f1=11.9 ∠ 345g ∠ °;

4. simulate the vibration A after obtaining first time test mass ₁=19.19 ∠ 152 μm pp ∠ ° and B ₁=13.34 ∠ 134 μm pp ∠ °, and be decomposed into symmetrical components A according to (5) formula, (6) formula _d1=16.07 ∠ 144 μm pp ∠ ° and antisymmetric component A _f1=3.85 ∠ 184 μm pp ∠ °;

5. calculate according to (7) formula, (8) formula the influence coefficient that symmetry increases the weight of to increase the weight of with antisymmetry respectively: α _d1=0.516 ∠ 150, α _f1=0.212 ∠ 186;

6. repetitive process 3,4,5, obtains the symmetrical influence coefficient increasing the weight of to increase the weight of with antisymmetry of second time, α _d2=0.705 ∠ 18, α _f2=0.213 ∠ 104;

7. according to (9) formula, (10) formula calculate that symmetry increases the weight of to increase the weight of with antisymmetry respectively counterweight amount: Q _d1=-21.6g, Q _f1=-6.2g, Q _d2=-2.7g, Q _f2=-0.4g;

8. according to (11) formula, (12) formula, (13) formula, (14) formula, symmetrical components and antisymmetric component are synthesized, obtain P ₁, P ₂, P ₃, P ₄the counterweight M of place section ₁=22.4 ∠ 309g ∠ °, M ₂=22.4 ∠ 342g ∠ °, M ₃=2.7 ∠ 47g ∠ °, M ₄=2.7 ∠ 63g ∠ °;

9. P ₁, P ₂, P ₃, P ₄the counterweight M of place section ₁, M ₂, M ₃, M ₄be input in ANSYS software and again do transient equilibrium analogue simulation, obtain vibration A=1.43 ∠ 198 μm of pp ∠ ° of the rear measuring point of new balance, B=1.98 ∠ 192 μm of pp ∠ °.

Table one is transient equilibrium simulation process during 3300rpm and result (amount of overstriking is vector).As can be seen from table, after transient equilibrium, the vibration of measuring point A and measuring point B reduces 87% and 78% respectively, illustrates that the dynamic balance method that the present invention carries is accurately feasible in theory.

Table one

Embodiment 2

The dynamic balance method that this example utilizes the present invention to propose carries out spot dynamic balance experiment, as shown in Figure 4.The hard bearing balan of Shanghai Schiak Testing Machinery Co., Ltd. is adopted under 2700rpm, to carry out the two test mass balancing method experiment of asymmetrical rotor to certain horizontal screw centrifuge helical rotor.Concrete transient equilibrium process is as follows:

1. measure the original vibration A of measuring point ₀=3.51 ∠ 93 μm pp ∠ ° and B ₀=3.024 ∠ 89 μm pp ∠ °;

2. calculate symmetrical components A according to (1) formula, (2) formula _d0=3.265 ∠ 91 μm pp ∠ ° and antisymmetric component A _f0=0.268 ∠ 293 μm pp ∠ °;

3. as shown in Figure 3, at selected test mass point P ₁, P ₂examination increases the weight of m respectively ₁=30 ∠ 140g ∠ ° and m ₂=30 ∠ 50g ∠ °, are decomposed into symmetrical components m according to (3) formula, (4) formula _d1=21.21 ∠ 95g ∠ ° and antisymmetric component m _f1=21.21 ∠ 5g ∠ °;

4. simulate the vibration A after obtaining first time test mass ₁=4.293 ∠ 121 μm pp ∠ ° and B ₁=3.856 ∠ 99 μm pp ∠ °, and be decomposed into symmetrical components A according to (5) formula, (6) formula _d1=3.999 ∠ 111 μm pp ∠ ° and antisymmetric component A _f1=0.806 ∠ 364 μm pp ∠ °;

5. calculate according to (7) formula, (8) formula the influence coefficient that symmetry increases the weight of to increase the weight of with antisymmetry respectively: α _d1=0.067 ∠ 160, α _f1=0.035 ∠ 24;

6. repetitive process 3,4,5, obtains the symmetrical influence coefficient increasing the weight of to increase the weight of with antisymmetry of second time, α _d2=0.080 ∠ 131, α _f2=0.062 ∠ 78;

7. according to (9) formula, (10) formula calculate that symmetry increases the weight of to increase the weight of with antisymmetry respectively counterweight amount: Q _d1=-63g, Q _f1=-5.7g, Q _d2=-77.7g, Q _f2=5.3g;

8. according to (11) formula, (12) formula, (13) formula, (14) formula, symmetrical components and antisymmetric component are synthesized, obtain P ₁, P ₂, P ₃, P ₄the counterweight M of place section ₁=63.3 ∠ 100g ∠ °, M ₂=63.3 ∠ 90g ∠ °, M ₃=78 ∠ 9g ∠ °, M ₄=78 ∠ 1g ∠ °;

9. at P ₁, P ₂, P ₃, P ₄place section counterweight M ₁, M ₂, M ₃, M ₄, again do dynamic balancing measurement, be balanced vibration A=0.98 ∠ 96 μm of pp ∠ ° of rear measuring point, B=0.99 ∠ 90 μm of pp ∠ °.

Table two is experiment of dynamic balancing process during 2700rpm and result (amount of overstriking is vector):

Table two

In this test, two measuring points are positioned on bearing seat, and its vibration speed value and phase place corresponding to vibration velocity can directly read on dynamic balancing machine, just can obtain vibration amplitude to vibration velocity integration, by the judge value of vibration amplitude as vibration.As can be seen from table, after transient equilibrium, the vibration of measuring point A and measuring point B reduces 72% and 67% respectively, illustrates that the dynamic balance method that the present invention carries is accurately feasible in practice.

Claims (5)

1. the two test mass balancing method of asymmetrical rotor, is characterized in that, comprise following steps:

(1) the original vibration of rotor two measuring points is measured;

(2) choosing the test mass point test mass simultaneously of two axially different positions, calculating the influence coefficient that symmetry increases the weight of to increase the weight of with antisymmetry when not considering test mass point phase characteristic;

(3) choose the test mass point that second group of position is different, repeat previous step, obtain second group of symmetry and increase the weight of to increase the weight of influence coefficient with antisymmetry;

(4) increase the weight of influence coefficient according to two symmetries respectively and two antisymmetry increase the weight of influence coefficient, calculate to eliminate and add weight required for original symmetric vibration and antisymmetric vibration.

(5) symmetry calculated is added weight and antisymmetry to add weight and carry out Vector modulation, obtain the counterweight amount in cross section, each test mass point place, hamming.

2. the two test mass balancing method of asymmetrical rotor as claimed in claim 1, is characterized in that the balance of two measuring points at least needs four test mass points.

3. the two test mass balancing method of asymmetrical rotor as claimed in claim 1, it is characterized in that the phase place often organizing test mass point preferably differs 90 °, the phase place of second group of test mass point and first group of test mass point also differs 90 °.

4. the two test mass balancing method of asymmetrical rotor as claimed in claim 1, is characterized in that any one test mass point that any one the test mass point increased the weight of for the first time can increase the weight of with second time be positioned at same axial cross section.

5. the two test mass balancing method of asymmetrical rotor as claimed in claim 1, is characterized in that symmetry increases the weight of to increase the weight of the amount of unbalance that influence coefficient is only applicable to test mass point place with antisymmetry.