DD213054A1 - METHOD FOR OPERATIONAL BALANCING - Google Patents

Abstract

The invention relates to a method for operationally balancing stationary units with computer-controlled imbalance measuring devices. The aim and object of the invention is, despite non-linear relationships between rotor imbalance and measured vibration quantities, even at not exactly constant speed, to reduce the Unwuchtreduzierverhaeltnisse when reducing the measuring runs. This is achieved by storing on a non-volatile storage medium influencing coefficients of an operationally mounted rotor at different rotational speeds and rotor imbalances. The storage medium assigned to a specific type of rotor is entered into the unbalance measuring device and read out by a balancing program which, according to the measured balancing speed and the determined oscillation quantities, uses the data stored on the storage medium to determine the actual influencing coefficients which are used to determine the imbalances in the balancing planes , The application is expediently carried out at the rotor manufacturers. Already during the development of the unit (pumps, compressors, turbines, generators, inductors), the influence coefficients are calculated and measured once and expediently stored in the form of a parameter field with the balancing program on a storage medium, usable for a rotor type.

Description

G 01 M 1/00

Method for operational balancing Field of application of the invention

The field of application of the invention extends to a method for the operational balancing of stationary units. ,

A special field of application is a method for operational balancing with computer-controlled imbalance measuring devices into consideration.

Characteristic of the known technical solution

From Plaza, H. "Possibilities of measured value processing ...", Port step report of the VDI journal series 11, No. 10, 1971; El-Hadi "Critical investigation and further development of the methods for balancing ..." Diss. TH Darmstadt; ISO-Smplehlung 2371 and KDT-recommendation Balancing Technique II, KDT Suhl is well known for the operational balancing of rigid rotors by measuring.Vectoral vibration quantities, such as vibration displacement, vibration velocity or vibration acceleration according to size and

Phase position at two spatially different points of the unit to be balanced, to close the imbalances of the rotor in two structurally specified balancing planes.

For this, it is necessary to perform the measurements successively, in the original state of the rotor, after applying a test imbalance of known size and .Yv'inkellage in - level of equalization I and after applying the known test imbalance in level II.

From the six vectorial oscillation quantities obtained in three cycles of the stationary and operational rotor to be balanced, the complex influencing coefficients and the imbalances of the rotor in the balancing planes I and II can be determined by means of graphical or analytical evaluation methods.

From the six Schwingungsgr.größen can be known. Way also by means of a computer program in microcomputer-controlled unbalance, the imbalances of the unbent rigid rotor to be calculated directly and displayed to compensate for this by mass corrections in the balancing planes z. B. by screwing masses to eliminate. Due to the generally occurring in the operating condition of the rotor large mechanical spurs and "unavoidable measurement and compensation error Unwuchtreduzierverhältnis is relatively low, so that'meist still more Meßläufe and mass corrections are necessary to reduce the imbalance of the rotor up to predetermined tolerance values.

A disadvantage here is that the complex determined in the first three runs as an intermediate result of the computer program of the microcomputer complex

Influence coefficients generally represent not only dependent on the geometric arrangement constants, but are also dependent on the size of the rotor 'unbalance. Therefore, in further balancing steps with decreasing rotor imbalance, the imbalance reduction ratio becomes smaller and smaller as a result of changed influencing coefficients and thus the number of necessary balancing steps becomes even greater. , , ·

Furthermore, it is known, after each balancing step, three measuring runs with each reduced test imbalance en, also to measure six vibration magnitudes, with which more accurate calculation results and a larger Unwuchtreduzierverhältnis can be achieved.

A disadvantage of both methods, the high number of necessary Meßläufe and thus low labor productivity when balancing.

Furthermore, it is disadvantageous that the. Speed must be the same for all measuring runs of the rotor to be balanced. Low rotational speed deviations between the measuring runs falsify the measurement results as a result of the speed dependence of the complex influencing coefficients and further reduce the imbalance reduction ratio.

Object of the invention

The aim of the invention is to increase the unbalance reduction ratios in the case of methods for operational balancing despite nonlinear relationships between rotor imbalance and measured vibration variables, even if the rotational speed is not exactly the same

and increase labor productivity. , ..

Explanation of the essence of the invention

The deficiency described in the characteristic of the known technical solution can be attributed to the insufficient consideration of the non-linear relationship between the measured vibration quantities and the respective size of the rotor imbalance as well as the speed dependence of the complex influencing coefficients.

To overcome these causes, the invention has for its object to find a method for operational balancing stationary units, with the reduction of the test runs large Unwuchtreduzierverhältnisse are reached, according to the invention this is achieved in that on a non-volatile storage medium, for example on a digital magnetic tape cassette or on an EPROM circuit, in the form of a parameter field, the influencing coefficients of an operatively mounted rotor are stored at different speeds and rotor imbalances. For balancing a certain rotor type stored operationally the associated storage medium is entered into the unbalance measuring device and read the Baten from the microcomputer by a balancing program. This balancing program determines according to the measured balancing speed and the determined vibration quantities by means of the data stored on the storage medium by interpolation, the actually auf'diesem run of the balancing

Rotor's true coefficients of influence used to determine imbalances in the balancing planes. Preferably, the influencing coefficients and the balancing program are to be stored together on the storage medium.

embodiment

The invention will be explained in more detail below using an exemplary embodiment. ' _:

The influencing coefficients for different rotor speeds and different rotor imbalances, which are determined once only for a certain rotor type under operational storage conditions, are expediently stored together with a balancing program, for example on a digital magnetic tape cassette.

For operational balancing of a rotor of certain types, the associated magnetic tape cassette is inserted into a microcomputer controlled unbalance meter.

The unbalance measuring device determines the actual balancing speed and two complex oscillation quantities at two measuring points of the stationary unit from a measuring run of the rotor.

On the basis of the balancing program determines the microcomputer of the unbalance measurement from balancing speed and the measured vibration variables by interpolation of the field of stored influencing coefficients the rotor imbalance in two structurally predetermined balancing planes.

The advantages of the method result from the specific determination of influencing coefficients of a rotor type determined once, taking into account their rotational speed dependency and taking into account the nonlinear relationship between rotor imbalance and measured vibrational quantities. Thus, a greater accuracy in the unbalance determination is achieved, increases the Unwuchtreduzierverhältnis and significantly reduces the number TO of the necessary measuring runs to achieve a given unbalance tolerance,

Claims (2)

-J- invention claim 1. A method for operational balancing stationary units with a computer-controlled imbalance 'and a nonvolatile storage medium, characterized in that the nonvolatile storage medium, stored in the £ in Orm a parameter field, the influencing coefficients of an operatively mounted rotor of a particular type at different balancing speeds and different Rotorunwucht en are entered into the unbalance measuring device and the data are 'read out' by the microcomputer by a balancing program that determines according to the measured 'balancing speed and the determined vibration variables by interpolation of the data stored on the storage medium, the actual influencing coefficients and calculates the rotor imbalance in two balancing planes. 2. The method according to item 1, characterized in that the influencing coefficients and the balancing program are preferably stored together on the storage medium.