SU983466A1 - Device for mechanism vibration diagnostics - Google Patents

Description

(54) DEVICE FOR VIBRODIAGNOSTICS MECHANISMS

The invention relates to measuring and diagnostics tools, and can be used, for example, to determine the state of rotating mechanisms from vibration parameters.

The closest to the invention to the technical essence is a device for vibrodiagnostics, which contains a vibration transducer connected in series to its output by a serially connected spectrum analyzer, an averaging unit connected in parallel to it. the outputs are two keys, two peak detectors associated with them, the zero set inputs of which are connected to the spectrum analyzer syntax output, a ratio meter connected to the output of the last detector, and the rotation speed sensor associated with the object to be controlled by the input to the outputs of the peak detectors.

In the United States, the position of the harmonics of the vibration signal along the frequency axis is monitored during the sweep of the spectrum. The condition of the mechanism 11 is judged by the ratio of the amplitudes in the two selected frequency bands. However, the known device has insufficient accuracy and noise immunity,. due to the low accuracy of tracking the position of the harmonics along the frequency axis, which is limited by the accuracy of the tachometer sensors used as a speed meter.

The aim of the invention is to improve the accuracy and noise immunity of the control.

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The goal is achieved by the fact that a device for vibrodiagnostics, containing a vibration transducer, connected to its output is a serially connected analyzer

15 spectrum, averaging unit, two keys connected in parallel to its outputs, two peak detectors associated with them, the zero set inputs of which are connected to the synchronization output of the spectrum analyzer, the ratio meter connected to the output of the peak detectors, the ratio meter connected to the output of the last indicator and the rotational speed sensor associated with the object is equipped with two identical strings consisting of each of the serially connected frequency multipliers and a synchronously tunable bandwidth.

30 filter and amplitude discriminator, the output of which is connected to the control input of the key, a programmable unit whose outputs are connected to the control inputs of the frequency multipliers, the second inputs of which are connected to the output of the rotation speed sensor, made in the form of serially connected pulse frequency sensor and raiser pulses, and the control inputs of synchronously tunable bandpass filters are connected to the clock output of the spectrum analyzer.

Figure 1 shows the block diagram of the device; figure 2 - the timing diagram of the work.

The device for vibrodiagnostics contains a vibrator 1 attached to the object 2, connected in series to the output of the vibration converter 1 spectrum analyzer 3, averaging unit 4 associated with the object 2 of monitoring the frequency-pulse rotation speed sensor 5 with the driver 6 pulses, two of which are connected to the output identical chains, consisting each of a series-connected multiplier of 7 or 8 frequencies, a synchronously tunable band-pass filter 9 or 10, and an amplitude discriminator 11 or 12, the outputs of which x are connected to the control inputs of the keys 13, 14, respectively. The Immediate block of 15 outputs is connected to the control inputs of the multipliers 7 and 8 frequencies. The outputs of the keys 13 and 14 are connected through peak detectors 16 and 17 to the ratio meter 18, the output connected to the indicator 19.

The device works as follows.

An electrical signal from the output of the vibration converter 1, proportional to the vibration of the object 2, is fed to the input of the spectrum analyzer 3 and in the form of a cyclic sweep along the frequency axis proportional to the time axis is fed to the input of the averaging unit 4, which produces a continuous averaging of the spectrum. The averaged spectrum from the output of block 4 averaging is supplied to the signal inputs of the keys 13 and 14.

The beginning of each spectrum sweep cycle is accompanied by sending a clock pulse 20 (Fig. 2a) from the output of the spectrum analyzer 3 to the control inputs of the synchronously tunable band-pass filters 9 and 10 and the installation inputs of the zero-peak detectors 16 and 17.

The pulse sequence from the output of the rotational speed sensor 5 is proportional to the rotational speed of the object 2, through the driver 6 pulses to the inputs of two control multipliers 7 and 8 frequencies.

The required magnitude of the multiplication factors is determined by the harmonic numbers selected for the vibration analysis and is set by the software control block 15 using the control BXOI multipliers 7 and 8. At the outputs of the frequency multipliers 7 and 8, harmonic signals are generated with frequencies equal to the frequencies selected for vibra analysis of harmonic components, permanently present at the inputs of synchronously tunable filters 9 and 10.

With the arrival of the sync pulse to the control inputs of filters 9 and 10 from the output of the analyzer 3, the spectrum is synchronized, with the analyzer sweep in time, the frequency tuning of the passbands of the synchronously tunable bandpass filters and the frequency range Wc-W, where is the initial frequency of the analyzer; V / c is the final frequency of the scan of the spectrum analyzer 3 (Fig. 2b).

Let harmonic components with frequencies W and dy be selected for analysis. Then at time t (tj, respectively) of the synchronously tunable band-pass filter 9 (and 10 respectively) at the output of the synchronously tunable filter 9 and respectively 10, a signal will arise that passing the amplitude discriminator 11 (respectively 12) will open the key 13 (respectively 14) allowing passage the signal from the output of block 4 averaging to the input of the peak detector 16 (respectively 17).

Since at times t. and t at the output of the analyzer 3 of the spectrum there were averaged voltages of harmonic components selected for analysis with frequencies V and d, then the peak detectors 16 and 17 respectively remembered their maximum values.

The relationship meter 10 measures the ratio of the maximum values obtained at the peak detectors 16 and 17 of the signals. If the ratio exceeds the set value, the indicator 19 is triggered.

The use of a device with a frequency-pulse rotation speed sensor in combination with frequency multipliers and synchronously tunable band-pass filters significantly increases the resistance to external interference and the reliability of control.

Claims (1)

Invention Formula . A device for vibrodiagnostics of mechanisms, containing a vibrator, connected to its output by a serially connected spectrum analyzer, averaging unit. two keys connected in parallel to its outputs, connected to them by inputs, two peak detectors, the zero set inputs of which are connected to the analyzer's synchronization output, the ratio meter connected to the output of the last detector connected to the output of the peak detectors, and associated with the object — The control is a rotation speed sensor, characterized in that, in order to increase the accuracy and ncwiexo stability, it is equipped with two identical chains consisting of a series of frequency multipliers connected in series, nhronno ne tunable bandpass filter and an amplitude discriminator output which is connected to the control input of the key, a program block whose outputs are connected to the control inputs of the frequency multipliers, the second inputs of which are connected to the output of the speed sensor, made in the form of serially connected frequency pulse sensor and pulse shaper, and the control inputs of the synchronic tunable bandpass filters are connected to the synchronization output of the spectrum analyzer. Sources of informa tion, accepted in the examination at examination 1. USSR author's certificate 670822, cl. G 01 H 1/04, 1979 prototype). but fO w " fV th / rd / f  L / Cfmi Phi1.1 x