CN1269504A

CN1269504A - Two-point measuring method of rotor unbalance

Info

Publication number: CN1269504A
Application number: CN 99116421
Authority: CN
Inventors: 黄震西
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-04-06
Filing date: 1999-04-06
Publication date: 2000-10-11

Abstract

The present invention relates to a method for balancing rotary machinery, and adoption of said invented method has no need of phase discrimnator equipment, and according to the primary vibration value of equipment which is measured on base frequency and the vibration value measured twice and resulted from test weight of given and known mass and phase it makes analytical calculation or geometrical construction to solve the unbalanced quantity and phase of rotary machinery to make rotary machinery balance.

Description

Two-point measuring method of rotor unbalance

Rotating machinery is industrial the most frequently used a kind of machinery, on commercial Application, often will carry out balance to rotating machinery, to reduce the vibration of machinery.The invention provides a kind of easy method, measure the amount of unbalance of rotating machinery, thereby rotating machinery is carried out balance.

On commercial Application, generally adopt the single or double method that rotating machinery is carried out balance.Slewing is in operational process, can be subjected to factor affecting such as medium wearing and tearing, cause rotor quality irregular, these imbalances are behind the compose operation of exertin, if can focus on the spin balancing plane, ignore the influence of unbalanced couple, just can adopt single side method that rotating machinery is carried out balance.If but can not ignore the influence of unbalanced couple, the irregular amount of unbalance that causes of rotor quality needs two spin balancing plane involution power and resultant couple to carry out balance behind the compose operation of exertin at least.Be that single side method can carry out balance to making a concerted effort, and two-sided method not only can be carried out balance to making a concerted effort, and can carry out balance resultant couple.But, no matter adopt which kind of method, all need measurements and calculations to go out the amount of unbalance of rotor, promptly obtain and make a concerted effort or the size and Orientation of resultant couple, therefore need measurements and calculations make a concerted effort or resultant couple is a vector.The domestic and international at present mensuration to rotor unbalance value generally adopts influence coefficient method, an i.e. given known quality and on balancing plane with respect to the single test mass or the couple test mass of rotation center position, according to the situation that increases test mass porpoise and phase change, the unit's of calculating test mass calculates original amount of unbalance according to this influence again to the influence of vibration and phase place.This assay method not only needs the vibration measuring device, also needs to have a phase demodulation apparatus, utilizes these two kinds of devices can measure the size and the phase place of amount of unbalance, and still, this device has increased the cost of equipment.

I have found out a kind of new amount of unbalance method for measuring through years of researches, and this method only needs the vibration measuring device and do not need phase demodulation apparatus also can measure the size and the phase place of amount of unbalance.The principle of this method is such: at first measure original vibration values A0, a given known quality and on balancing plane again with respect to the single test mass or the couple test mass of rotation center position, the phase place that can set this position is 0, radius R is measured the vibration values A1 that adds test mass for the first time; Then, this same unit test mass or power couple test mass revolved turn 90 degrees, be that phase place is 90 degree, radius still is R, measure the vibration values A2 that adds test mass for the second time again,, adopt the method for drawing or analytical Calculation then according to its phase relation and vibration values size variation, obtain the size and the phase place of original unbalance, thereby rotor is carried out balance.

The method of analytical Calculation is such, and the phase place of establishing original vibration is X, and adding the phase place of synthesizing behind the test mass for the first time is Y, adding for the second time the phase place of synthesizing behind the test mass is Z, and the quality of test mass is G, establishes and does not consider original vibration effect, only the vibration values that is risen by the test mass shadow is A, and it is as follows to establish an equation thus:

A0 ^*SinX＝A1 ^*SinY (1)

A0 ^*CosX+A＝A1 ^*CosY (2)

A0 ^*CosX＝A2 ^*CosZ (3)

A0 ^*SinX+A＝A2 ^*SinZ (4)

By above four equations, can calculate the phase place X of original vibration, test mass influence coefficient K=G/A, and then calculate the needed counterweight G0=A0 of original vibration ^*K.

The method of drawing is such, as shown in Figure 4, in coordinate system, is the center of circle with O, and vibration values A0 is that radius is drawn circle O; Be the center of circle to justify the intersection point A of O on X-axis then, vibration values A1 is that radius is drawn circle A; Be the center of circle to justify the intersection points B of O on Y-axis again, vibration values A2 is that radius is drawn circle B; If the intersection point of circle A and circle B is C, D 2 points, then vectorial OC and OD are exactly the possible vector of amount of unbalance, compare OC or the mould of OB and the size of original vibration again, and what its difference was little promptly is the amount of unbalance of rotor.

Below, we are with reference to the step of description of drawings rotor balancing:

In Fig. 1, the 1st, rotor, the 2nd, balanced surface, the 3rd, axle, the 4th, the end bearing that moves about, the 5th, stop end bearing, the 6th, test mass.In Fig. 2,1 counterweight for the second time, the 2nd, rotor, the 3rd, counterweight for the first time, the 4th, axle.In Fig. 3, the 1st, rotor, the 2nd, balanced surface, the 3rd, axle, the 4th, the end bearing that moves about, the 5th, stop end bearing, the 6th, test mass, the 7th, test mass.

The step of practical application is such, at first the vibration that goes out rotor according to the structure decision of rotor mainly be because make a concerted effort or since resultant couple cause, so just can determine that first employing single side method still is that two-sided method is carried out balance.Second step was to measure the vibration values A0 of rotor on fundamental frequency.According to the selected suitable test mass of factors such as the diameter of rotor, quality, rotating speed, establishing quality is G again.The 3rd step, as shown in drawings, shut down and test mass is welded on the balanced surface, when adopting the single plane balancing method, only use a test mass, as shown in Figure 1, the test mass weldering is tied on the outer rim of balanced surface; And when adopting the two plane balancing method, then need the test mass of two identical weight, and being the diagonal angle simultaneously to weld knot respectively on the outer rim of two balanced surfaces, they are 180 degree angles with respect to the centre of gyration, as shown in Figure 3.Starting outfit is measured the vibration values A1 of rotor on fundamental frequency once more.The 4th goes on foot, and shuts down and test mass is taken off, and revolves by sense of rotation to turn 90 degrees, and welds former test mass once more, measures fundamental vibration value A2 after the startup.By analyzing the position relation between relatively A0, A1, A2 and twice test mass, calculate the phase place and the quality of rotor unbalance value, take off test mass, the counterweight that calculates in the welding, starting outfit is finished equilibrium process.

Adopt this method to carry out rotor balancing, promptly can be used for the balance of equilibrator, also can be used for balance on the online machine.Utilize this patent to be compiled into balance software, only need easy instrument, just can carry out balance, therefore have very wide range of application rotating machinery.

Claims

1, a kind of measurements and calculations method of slewing amount of unbalance, this method does not need phase demodulation apparatus, and it causes that by measuring three slewings the size of fundamental vibration value calculates amount of unbalance on bearing.

2, the said measurement of claim 1 is for three times to realize like this, measure the original vibration that causes by amount of unbalance for the first time, measure caused vibration after arbitrary position adds test mass on the balanced surface for the second time, the vibration of Ce Lianging for the third time is to take off previous test mass, revolve turn 90 degrees after, be added on the balanced surface vibration values that starting outfit is measured again.

3, claim 1 said computing method comprise two kinds of analytical Calculation and drawings, and the formula of analytical Calculation is as follows:

A0 ^*SinX＝A1 ^*SinY (1)

A0 ^*CosX+A＝A1 ^*CosY (2)

A0 ^*CosX＝A2 ^*CosZ (3)

A0 ^*SinX+A＝A2 ^*SinZ (4)

In the equation, the phase place of original vibration is X, and vibration values is A0, and adding the phase place of synthesizing behind the test mass for the first time is Y, vibration values is A1, and adding the phase place of synthesizing behind the test mass for the second time is Z, and vibration values is A2, the quality of test mass is G, does not consider original vibration effect, and only the vibration values that is risen by the test mass shadow is A.Can calculate the phase place x and the counterweight G of amount of unbalance thus ^*A0/A.

4, claim 3 said drawings are such, set up coordinate system, are the center of circle with O, and vibration values A0 is that radius is drawn circle O; Be the center of circle to justify the intersection point A of O on X-axis then, vibration values A1 is that radius is drawn circle A; Be the center of circle to justify the intersection points B of O on Y-axis again, vibration values A2 is that radius is drawn circle B; If the intersection point of circle A and circle B is C, D 2 points, then vectorial OC and OD are exactly the possible vector of amount of unbalance, compare OC or the mould of OB and the size of original vibration again, and what its difference was little promptly is the amount of unbalance of rotor.