SU1472781A1 - Method of vibrational diagnosis of rotor machine condition - Google Patents

Abstract

The invention relates to a vibration measuring technique and can be used for the vibration diagnosis of rotary machines. The aim of the invention is to increase the reliability of diagnostics of the technical condition of rotary machines. The reaction of the machine design to the force effect, measured at the installation sites of vibration transducers 1, is different. By constructing a diagram of the values of the signal level of the vibration transducers and selecting the constant component, we obtain a curve of complex shape, from which the spectral components of interest are filtered out. Having determined the parameters of the selected components of the spectrum, we judge the type and size of the defects. 1 il.

Description

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The invention relates to a vibration measuring technique and can be used for the vibration diagnosis of rotary machines.

The aim of the invention is to increase the reliability of diagnostics of the technical condition of rotary machines.

The essence of the method is as follows.

The reaction of the design of machines to force, measured at the places of installation of vibration transducers, is different. By constructing a diagram of the value of the SRI of the signal of the vibrating transducers and selecting the constant component, a curve of complex shape is obtained, from which the spectral components of interest form the filter (first, second harmonics of the rotation frequency, and so on).

To the identifier, the selected spectral components are defined as the pattern and type of defects.

The drawing shows a block diagram of a device that implements the method,

The device contains a switch 1 connected in series, the inputs of which are connected to video transducer outputs, an adder 2, a filter unit 3 and a measurement and display unit 4. To control the operation of switch 1, there is a circuit formed by series-connected pulse generator 5, a delay line 6 and a shift 7 connected to the control input of switch 1,

The device that implements the method works as follows.

In the case where there are no defects in the design of the machine body, the vibrations caused by the action of a rotating force will be harmonic with the rotor speed. The signal of each vibration transducer is a sinusoid shifted in phase relative to the signals of other vibration transducers. At the output of the adder 2, the signal is a curve, the constant component of which characterizes the magnitude of the imbalance of the rotor.

If there are defects (change in stiffness, shaft displacement, distortions), the reaction to the influence of the rotating force at various points in the structure

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is changing. By selecting the constant component characterizing the imbalance and the variable caused by the defect, it is possible after filtering the variable component to obtain the spectral components by. whose parameters determine the type and size of the defect. The use of a rotating coordinate, obtained as a result of the switching of vibroconversion-. provides for the separation of spectral components with rotational frequencies caused by rotor imbalances and other defects. The oscillations caused by the imbalance of the rotor, have a constant projection on the moving coordinate axis, as the latter rotates synchronously with the driving force. Reactions to rotating, caused by defects, have time-varying projections on the rotating, coordinate axis, since the defect is attached to a specific construction site.

The signals of the vibration transducers are fed to the inputs of the controlled switch 1, which in turn connects them to the adder 2 in turn. The output signal of the adder 2 is supplied to the unit. 3 filters for separation into components, and then into unit 4 of measurement. and indications. The switch 1 is controlled by a pulse generator 5, a delay line 6. and a shift register 7. The frequency of the generator 5 is chosen such that the number of pulses received at the output per rotor rotation is equal to the number of vibration transducers. The shift register 7 is designed to control the keys (not shown) of the switch 1, Line 6 of the delay provides the selection of the moment of connection of the vibration transducers so that the axis of the rotation coordinate coincides with the vector of the vibrating force.

Claims (1)

Invention Formula The method of vibration diagnostics of the technical condition of the rotor machines, which consists in alternately measuring the vibration parameters at points evenly distributed fio of the machine design during the interval, time L t, 3 14727814 where T is the period of oscillation; n is the numerical value of the constant component the points at which the parameters are measured, from the measured values at different differences in that the intervals of time, in terms of which in order to increase reliability, estimate the magnitude of oscillations per hour-measured signals summarize, sum-1 the measured signal is divided into a constant n-from f ---, where the T, -period and the first and variable components, the harmonics of the rotational frequency are rotated for a period of time, during which the parameters of the variable are measured. vibration parameters, (which judge the types and magnitude at each point, result in maximum defects.