JP2008102049A - Balance correction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a balance correction device capable of reducing simply and surely a vibration amplitude in a rotational speed range including a rotational speed range wherein speed cannot be increased at a balance correction time. <P>SOLUTION: This device has an influence coefficient input means 1 for inputting an influence coefficient between a vibration vector and an unbalance vector, an influence coefficient storage means 2 for storing the influence coefficient, a vibration vector measuring means 3 for measuring each measured vibration vector at single of a plurality of inspection rotation speeds, an estimated unbalance vector operation means 4 for operating an estimated unbalance vector based on the measured vibration vector and the influence coefficient, an estimated vibration vector operation means 5 for operating an estimated vibration vector based on the estimated unbalance vector and the influence coefficient, and an unbalance correction vector operation means 6 for operating an unbalance correction vector based on the estimated vibration vector and/or the measured vibration vector and the influence coefficient. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a balance correcting device, and is particularly suitable for correcting the balance of a high-speed turbomachine operated through a critical speed in a bending vibration mode.

  In a high-speed turbomachine that passes the critical bending speed, it is not possible to sufficiently reduce the vibration only by correcting the low-speed balance assuming that the rotor is a rigid body, and it is necessary to perform the high-speed balance correction using the vibration measurement result at the time of high-speed rotation. A high-speed balance correction method is disclosed in Patent Document 1, for example. In this balance correction method, the vibration vector of the rotor when the rotor is in a low rotation state and a high rotation state is measured with a vibration detector and a pulse detector, and the change vector and vibration vector of the unbalance vector on the correction surface are obtained in advance. The measured vibration vector is linearly converted based on the linear relationship with the change vector, and the change vector of the unbalance vector necessary to reduce the measurement vibration vector to the zero vector is calculated as the unbalance correction vector.

  A method of calculating an unbalance correction vector using an influence coefficient indicating the relationship between an unbalance vector and a vibration vector is generally called an influence coefficient method. The above method is an improvement of the influence coefficient method. By measuring the vibration vector of the rotor when the rotor is in a low rotation state and a high rotation state, only the measurement of the vibration vector performed before the rotor correction is performed. It is possible to determine a correction content in consideration of bending in a high rotation state. By applying this method, it is possible to reduce the vibration amplitude at the rotational speed at which the vibration vector is measured.

  As the calculation method of the influence coefficient, from the method of calculating analytically using numerical calculation means such as the finite element method and the vibration vector change when a trial operation is performed in advance and a known unbalance vector change is given. An experimental calculation method can be considered.

JP 2000-291408 A

  The rotational speed at which the vibration vector is measured at the time of balance correction will be referred to as the inspection rotational speed. In the high-speed balance method described above, in order to reduce the vibration amplitude at a certain rotational speed, it is necessary to measure the vibration vector at that rotational speed. However, there are cases where the speed cannot be increased to the maximum rotational speed due to insufficient power of the high-speed balance equipment. There is also a demand to perform high-speed balance correction at a rotation speed lower than the maximum rotation speed in order to shorten the time required for the acceleration. In such a case, since the vibration vector in the high rotational speed region above the inspection rotational speed range cannot be measured, the above-described high-speed balance correction method cannot reduce the vibration amplitude in the high rotational speed region.

  FIG. 2 is a schematic diagram showing the relationship between the rotation speed and the vibration amplitude. In the figure, the horizontal axis represents the rotation speed, and the vertical axis represents the vibration amplitude. In the figure, the one-dot chain line indicates the initial vibration amplitude, the broken line indicates the vibration amplitude of the balance correction result using the vibration vector in the inspection rotation speed range, and the solid line indicates the vibration amplitude of the ideal balance correction result. When the balance correction is performed using the vibration vector in the inspection rotation speed range as in the high-speed balance correction method described above, it is possible to reduce the vibration in the inspection rotation speed range as shown by the broken line in the figure. The vibration amplitude may increase in a rotation speed range higher than the inspection rotation speed range. Thus, even when the inspection rotational speed is lower than the maximum rotational speed, it is desirable that the vibration amplitude is reduced in the entire rotational speed range including the maximum rotational speed as shown by the solid line in the figure.

  An object of the present invention is to provide a balance correction device that can easily and reliably reduce vibration amplitude in a rotation speed range including a rotation speed range that cannot be increased during balance correction.

  In order to achieve the above object, a balance correction apparatus according to the present invention includes an influence coefficient input means for inputting an influence coefficient indicating a relationship between a vibration vector and an unbalance vector, and an influence coefficient storage means for storing the influence coefficient. Vibration vector measuring means for measuring an actual vibration vector at a single or a plurality of inspection rotational speeds, estimated unbalance vector calculating means for calculating an estimated unbalance vector based on the actual vibration vector and the influence coefficient, An estimated vibration vector calculating means for calculating an estimated vibration vector based on the estimated unbalance vector and the influence coefficient; and an unbalance for calculating an unbalance correction vector based on the estimated vibration vector and / or the actually measured vibration vector and the influence coefficient. It has a correction vector calculation means.

  Estimated unbalance vector calculating means for calculating an estimated unbalance vector based on the actually measured vibration vector and the influence coefficient, estimated vibration vector calculating means for calculating the estimated vibration vector based on the estimated unbalance vector and the influence coefficient, and the estimated vibration vector In addition, by calculating the unbalance correction vector based on the actually measured vibration vector and the influence coefficient, it is possible to estimate the vibration vector at the rotation speed indicating the relation between the vibration vector and the unbalance vector by the influence coefficient regardless of the inspection rotation speed. Therefore, it is possible to reduce the vibration amplitude in the rotational speed range including the rotational speed range in which the speed cannot be increased when the balance is corrected.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration diagram of one embodiment. An influence coefficient indicating the relationship between the vibration vector and the unbalance vector is input by the influence coefficient input means 1 and stored in the influence count storage means 2. As an influence coefficient in the present embodiment, an influence coefficient matrix of the following equation indicating a linear relationship between a vibration vector {A} at each rotational speed and vibration measurement position and an unbalance vector {U} at each correction surface (axial position) [ [alpha]] is used, but the influence coefficient matrix [[alpha]] may have a nonlinear characteristic that varies depending on the magnitude of the vibration vector {A}.

  As described above, the influence coefficient is calculated by analytically using a numerical calculation means such as a finite element method or when a trial run is performed in advance and a known unbalance vector change is given. It is conceivable to experimentally calculate from the vibration vector change. When the influence coefficient is calculated analytically, the influence coefficient at an arbitrary rotation speed can be calculated. Even when the influence coefficient is experimentally calculated, the influence coefficient at an arbitrary rotation speed can be calculated by performing several trial operations up to the maximum rotation speed in advance.

  The vibration vector measuring means 3 measures an actually measured vibration vector at a single or a plurality of inspection rotation speeds. In the present embodiment, it is assumed that the maximum rotational speed cannot be increased during balance correction. As the configuration of the vibration vector measuring means 3, for example, an eddy current displacement sensor and a tracking filter can be considered. The rotor vibration displacement is measured by an eddy current displacement sensor, and the rotation pulse is measured by detecting a key groove or the like provided at one place in the circumferential direction of the rotor by the eddy current displacement sensor. By inputting the measured rotor vibration displacement and the rotation pulse to the tracking filter and calculating, the amplitude of the rotor vibration of the rotation frequency component and the phase delay from the rotation pulse are calculated, and the actually measured vibration vector can be measured.

  The estimated unbalance vector calculation means 4 calculates an estimated unbalance vector based on the actually measured vibration vector and the influence coefficient. In the present embodiment, the estimated unbalance vector {U} is obtained by inputting the measured vibration vector {A} and the influence coefficient [α] using the influence coefficient method in consideration of the weight coefficient matrix [λ] shown in the following equation. However, other methods such as a modal balance method may be used. If the weight coefficient matrix is a unit matrix, the weightless influence coefficient method is used.

  In the process of calculating the estimated unbalance vector, an influence coefficient corresponding to the rotational speed and vibration measurement position of the actually measured vibration vector is selected and used.

  The estimated vibration vector calculation means 5 calculates an estimated vibration vector based on the estimated unbalance vector and the influence coefficient. In this embodiment, the estimated vibration vector {A} is calculated by inputting the estimated unbalance vector {U} and the influence coefficient matrix [α] into (Equation 1). By calculating the estimated vibration vector using the influence coefficients corresponding to all the rotation speeds and vibration measurement positions input to the influence coefficient input means 1, vibration vectors in a rotation speed range including a rotation speed range that cannot be accelerated during balance correction Can be estimated.

  The unbalance correction vector calculator 6 calculates an unbalance correction vector based on the estimated vibration vector and the influence coefficient. In this embodiment, the unbalance correction vector {U} is calculated by inputting the estimated vibration vector {A} and the influence coefficient [α] into (Equation 2). Since the unbalance correction vector is calculated based on the vibration vector in the rotation speed range including the rotation speed range that cannot be increased during the balance correction, the vibration amplitude in the rotation speed range including the rotation speed range that cannot be increased during the balance correction can be reduced. .

  FIG. 3 shows a configuration diagram of another embodiment. The difference from the first embodiment is that in the unbalance correction vector calculation means 6, the actual vibration vector measured by the vibration vector measurement means 3, the estimated vibration vector calculated by the estimated vibration vector calculation means 5, and the influence coefficient storage means 2 The unbalance correction vector is calculated based on the stored influence coefficient. In this embodiment, the actually measured vibration vector and the estimated vibration vector at a rotational speed other than the inspection rotational speed are used in combination. In the calculation of the unbalance correction vector at the inspection rotation speed, since the actually measured vibration vector having no estimation error can be used, the vibration amplitude can be more reliably reduced.

  In this embodiment, the axial distribution of the estimated unbalance vector is a distribution corresponding to the natural vibration mode of the rotor. The unbalance vector {U} is expressed by the following equation using the natural vibration mode matrix [φ] and the mode unbalance vector {δ}.

  The mode influence coefficient [α ′] is defined as follows:

  When (Equation 4) is used, (Equation 1) and (Equation 2) are transformed into the following equations.

  Since the unbalance distribution can be expressed by superposition of the mode unbalance vector {δ}, the distribution of the estimated unbalance vector in the axial direction is a distribution corresponding to the natural vibration mode of the rotor, so that an unbalance distribution closer to the actual state can be estimated. can do.

  FIG. 4 shows a configuration diagram of another embodiment. The difference from the second embodiment is that the estimated vibration vector calculation influence coefficient input means 7 for inputting the estimated vibration vector calculation influence coefficient for calculating the estimated vibration vector, and the unbalance correction for calculating the unbalance correction vector. This is to have an unbalance corrected vector calculation influence coefficient input means 8 for inputting a vector calculation influence coefficient. By using the influence coefficient for calculating the estimated vibration vector with a unified calculation method at each rotation speed, the estimation accuracy of the estimated vibration vector can be improved, and unbalance correction by selecting highly reliable data such as actual measurement results for each rotation speed Since the calculation accuracy of the unbalance correction vector can be improved by using the vector calculation influence coefficient, the vibration amplitude can be more reliably reduced.

  Further, by having an unbalance correction vector calculation means for calculating an unbalance correction vector based on an actually measured vibration vector, an estimated vibration vector at a rotation speed other than the inspection rotation speed, and an influence coefficient, the unbalance correction at the inspection rotation speed is achieved. Since the measured vibration vector having no estimation error can be used in the vector calculation, the vibration amplitude can be more reliably reduced.

  Also, input an influence coefficient input means for calculating an estimated vibration vector for calculating an estimated vibration vector and an influence coefficient input means for calculating an unbalance correction vector for calculating an unbalance correction vector. By using the influence coefficient input means for calculating the unbalanced correction vector, it is possible to improve the estimation accuracy of the estimated vibration vector by using the influence coefficient for the estimated vibration vector calculation that unifies the calculation method at each rotation speed, and for each rotation speed. Since the calculation accuracy of the unbalance correction vector can be improved by using the influence coefficient for unbalance correction vector calculation in which highly reliable data such as the actual measurement result is selected, the vibration amplitude can be more reliably reduced.

  In addition, by having an estimated unbalance vector calculation means for calculating an estimated unbalance vector based on an influence coefficient method using a weighted or unweighted least square method, the estimated unbalance vector can be calculated easily and with high accuracy. The vibration amplitude can be reduced easily and reliably.

Further, by having an unbalance correction vector calculation means for calculating an unbalance correction vector based on the influence coefficient method using the weighted or unweighted least square method, the unbalance correction vector can be calculated easily and with high accuracy. The vibration amplitude can be reduced easily and reliably.
In addition, the estimated vibration vector can be calculated more accurately by including the estimated unbalance vector calculation means that uses the axial distribution of the estimated unbalance vector as the distribution corresponding to the natural vibration mode of the rotor. Can be more reliably reduced.

The block diagram of the balance correction apparatus by one embodiment of this invention. The schematic diagram which shows the relationship between a rotational speed and a vibration amplitude. The block diagram by other embodiment. The block diagram by other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Influence coefficient input means 2 Influence coefficient storage means 3 Vibration vector measurement means 4 Estimated unbalance vector calculation means 5 Estimated vibration vector calculation means 6 Unbalance correction vector calculation means 7 Estimated vibration vector calculation influence coefficient input means 8 Unbalance correction vector Influence coefficient input means for calculation 9 Balance correction device

Claims (6)

An influence coefficient input means for inputting an influence coefficient indicating the relationship between the vibration vector and the unbalanced vector;
An influence coefficient storage means for storing the influence coefficient; a vibration vector measurement means for measuring an actual vibration vector at a single or a plurality of inspection rotation speeds;
Estimated unbalance vector calculation means for calculating an estimated unbalance vector based on the measured vibration vector and the influence coefficient;
Estimated vibration vector computing means for computing an estimated vibration vector based on the estimated unbalance vector and the influence coefficient;
Unbalance correction vector calculation means for calculating an unbalance correction vector based on the estimated vibration vector and / or the actually measured vibration vector and the influence coefficient;
A balance correction apparatus comprising:   The unbalance correction vector calculating means for calculating the unbalance correction vector based on the measured vibration vector, the estimated vibration vector at a rotation speed other than the inspection rotation speed, and the influence coefficient, according to claim 1. The balance correction apparatus characterized by having.   The estimated vibration vector calculation influence coefficient input means for inputting the estimated vibration vector calculation influence coefficient for calculating the estimated vibration vector, and an unbalance for calculating the unbalance correction vector. A balance correction apparatus comprising an influence coefficient input means for unbalance correction vector calculation for inputting an influence coefficient for balance correction vector calculation.   2. The balance correction according to claim 1, further comprising estimated unbalance vector calculation means for calculating the estimated unbalance vector based on an influence coefficient method using a weighted or unweighted least square method. apparatus.   2. The balance correction according to claim 1, further comprising an unbalance correction vector calculation means for calculating the unbalance correction vector based on an influence coefficient method using a weighted or unweighted least square method. apparatus. 2. The balance correcting apparatus according to claim 1, further comprising estimated unbalance vector calculation means for setting the axial distribution of the estimated unbalance vector to a distribution corresponding to the natural vibration mode of the rotor.

Images