SU996885A1 - Device for determination of rotor unsbalance vector parameters - Google Patents

Description

The invention relates to a balancing technique for determining the parameters of the imbalance vector and. can be used for balancing rotors of various machines, as well as precision machines in conditions of increased vibration of foundations.

A device is known for determining the parameters of a rotor unbalance vector, comprising a series-connected unbalance sensor, a tuning fork, a selective amplifier, a detector, a low-frequency amplifier, and a meter [1J.

However, the device is characterized by 15 insufficient accuracy in determining the parameters due to the fact that the measurement result of the unbalance vector parameters is influenced by the harmonics of the sensor output signal, which are interferences due to external vibrations that are not tuned in during the measurement.

The closest in technical essence to the invention is a device for determining the parameters of the rotor unbalance vector, containing an unbalance sensor connected in series, a reference sinusoidal voltage generator with a multiplication unit 30, a low-pass filter _t a low-frequency signal processing unit and a meter (£ 2) .

The disadvantage of this device is that from the resulting signal obtained by multiplying, you can select only its constant component, which does not carry information about the angle of the imbalance vector (the module can be judged by the level of this component). To determine the phase of the imbalance vector, additional transformations are necessary, namely, it is necessary to decompose the filtered signal into two orthogonal components, dividing the values of the components, find the tangent of the angular coordinate, and then determine the actual angular coordinate of the imbalance vector from the tangent value.

In the process of these transformations, additional information losses are inevitable, which reduce the accuracy of determining the phase of the imbalance vector.

The purpose of the invention is to increase the accuracy of determining the phase of the imbalance vector.

This goal is achieved by the fact that the device for determining the parameters of the rotor unbalance vector is equipped with a series-connected null-body, the input of which is connected to the second output of the shaper, circuit I, a time counter, the second input of which is connected to the output of the processing unit, and a multiplier-5 dividing unit the output of which is connected to the second input of the meter, as well as to the unit for measuring the period of the low-frequency component of the signal, connected between the low-pass filter and the multiplier-dividing unit and sensors th mark angle of the rotor rotation, a second input connected to circuit I.

In FIG. 1 shows a device 15 for determining the parameters of the rotor unbalance vector, general view; in FIG. 2 - stress diagrams.

The device for determining the parameters of the imbalance vector of the rotor of the 2Q rotor holds the imbalance sensor 1 connected in series, a reference sinusoidal voltage generator based on the multiplication unit 2 and a low-frequency generator 3, a low-pass filter 4, a low-frequency signal processing unit 5, which determines the maximum of the low-frequency component, and the imbalance meter 6, connected in series to the zero-organ 7, the input of which is connected to the second output of the former, circuit 8 And, counter 9 time, second the input of which is connected to the output of block 5 for processing the low-frequency component of the signal, and a multiplier-dividing unit .10, the output of which is connected to the second input of meter 6, as well as block 11 for measuring the period of the low-frequency component of the signal, connected between the low-pass filter 4 40 and a multiplier-dividing unit 10, and a sensor 12 of the angle of rotation of the rotor (not shown) connected to the second input of the circuit

and. 45

The device operates as follows.

When the rotor rotates at a balancing speed, from the sensor 1 to the block 2 of the shaper multiplication, electrical signals are proportional to the mechanical vibrations of the rotor. The frequency of these signals is f, i.e. this is the rotor speed. With an ideal voltage generator 3 is supplied to a frequency block 2. The frequency different from the frequency of the signal [) _minutes by a predetermined amount (enough to these signals differ 60 were 10%, for example = 55 Hz = 50 Hz). Then

And a. ^- BI _ i 50-55 / ₌ π 1 T _____, ₅₀ 0.1 _b5

At the output of block 2 get useful. a signal with a difference frequency Δί = f <z - and an interference signal with a frequency f <2_ + (,. These signals are fed to a low-pass filter 4, the output of which remains only the low-frequency component with a frequency Af = f _z -.

• At the time t _o , at which the zero phase of the reference voltage Uj, fixed by the zero-element 7, coincides, at (1, = 0 it outputs a signal to the logic circuit 8 I, and the rotor phase marks the imbalance of the sensor 1 (moments of passage through the rotor angle mark the imbalance sensor 1 is registered by the phase mark sensor 12, which also gives the corresponding signals to the logic circuit 8 I), the logic circuit 8 And starts the time counter 9. The counter is open until a signal from block 5 is generated at its inhibitory input, generated in moment to reach voltage Uc of its maximum value .. The same signal from block 5 reads information from counter 9 and transcribes it into a multiplier dividing block 10, to the other input of which information about the duration of period T from block 11 is received. Block 10 performs operations in accordance with φ = r · ~ -1 where ^{1 1} is the phase of the rotor unbalance vector;

At is the time interval, and gives the result of the measurement, the phase of the unbalance vector to meter%, which also receives a signal from block 5 that carries information about the module of the unbalance vector.

The error in determining the phase C) of the imbalance vector (when determining time intervals and T and setting the constant 2X with an error of 0.05%) does not exceed 0.2-0.3 °, which allows a 5-10-fold increase in the accuracy of determining the phase of the imbalance vector while maintaining the accuracy of measuring the amplitude of the imbalance vector.

Claims (2)

1. USSR author's certificate No. 390397, cl. G01 M 1/22, 1971. 2. Copyright certificate of the USSR 378034, cl. G01 M 1/22, 1969 10 (prototype). fi; /