SU1150548A1 - Device for measuring rotation speed non-uniformity - Google Patents

Abstract

DEVICE FOR MEASURING unevenness SPEED comprising alternator phase detector rogistrirz nvdee device and a rotational speed sensor, whose output is connected to one of the phase detector inputs, a second input connected to the output of the generator and output to registrirukitsemu device, characterized in that, in order increase the accuracy of measurement and expansion of the dynamic range of measurement of the unevenness of the rotation frequency; a functional transducer of the input frequency detuning in the amplitude of the synchronizing signal and the modulator, one input of which is connected via a functional converter to the output of the phase detector, the second input to the output of the rotational speed sensor, and the output connected to the input (L of the generator.

Description

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The invention relates to a measurement technique and can be used to measure and record an uneven rotation frequency.

The angular accelerometer is known, containing a symmetrical inertial mass, including a rotor, a ring, pins immersed in a damping fluid, the inertial mass is suspended in fixed supports by means of two preformed plate torsions, i.e. the axis of rotation of the rotor are the axes of the cylindrical supports of the torsions. A rack with two semiconductor transducers of movement into an electrical signal in the form of two beams is attached to one of the supports. The deformation of the beams is perceived by the bridge circuit formed on the beams in the immediate vicinity of the fixing point of the rack 1.

Disadvantages of this device

are a small range of measured accelerations, limited by the reversible range of elastic deformations. elements of the device, its structural complexity. To remove electrical signals from bridge circuits mounted on a rotating part, it is necessary to install special-purpose current collectors,

The closest to the technical essence of the invention is a device for controlling the dimensions of parts, the measured value of which is converted into a change in the frequency of the electrical signal. This device contains two oscillators, the frequency of one of them is a function of the measured parameter, the outputs of the oscillators are connected to the inputs of the phase detector, the output of which is connected to the recording device t2}.

The generator of this device operates in the capture mode, i.e. any detuning of the generator circuit leads to a change in the angle of the phase shift between the generator voltage relative to the synchronizing input signal.

The relationship between detuning in frequency and phase shift within the capture band is

. einMr- i,

TO) - detuning in frequency;

where T is the contour constant; g - degree of communication,

or

/ l. DiZ (rC5in-

In practice, this means that the instrument has a very narrow range of measurement of frequency oscillations with linear conversion.

The purpose of the invention is to increase the measurement accuracy and broaden the dynamic range of measurement of rotational frequency unevenness.

This goal is achieved in that a device for measuring the uneven rotation frequency, containing a gear mounted on a shaft, a generator, a phase detector, a recording device and a rotation frequency sensor, the output of which is connected to one of the inputs of the phase detector, the second input connected to the output of the generator, and output - to the registering device; a functional converter for detuning the frequency of the input signal into the amplitude of the synchronizing signal and a modulator, which one input is connected via a functional converter with an output of the phase detector, a second input with the output of a rotational speed sensor, and the output is connected to the input of the generator.

Introduction of a functional converter and modulator allows, by correcting the degree of coupling, to increase the measurement accuracy and to extend the linear range of the device for measuring rotational frequency unevenness.

FIG. Figure 1 shows a block diagram of a device for measuring rotational frequency unevenness; in fig. 2 - diagrams explaining his work.

A device for measuring the uneven rotational speed consists of a gear 2 mounted on the shaft 1 ,. a rotational speed sensor 3, a phase detector 4, a function converter for detuning the frequency of the input signal to the amplitude of the synchronizing signal 5, a modulator 6, a generator 7, a recording device 8.

Dp obtaining linearity conversion,

GCDU, 3 where K is the conversion factor. It is possible to obtain the dependence of the degree of communication (Fig. 2c): (Kiso) Now, if you change the degree of connection n of the output signal with the generator 7n according to this law as the value changes, then the dependence ш (шш) will be linear over the entire capture band Wash generator 7 (Fig. 2c). The device works as follows. When the shaft 1 rotates with the gear gear 2, the rotational speed sensor 3 forms a rectangular signal with a frequency (1; 2, where and) is the frequency of rotation of the shaft 1; z is the number of gear teeth 2. This signal is transmitted to one of the inputs of the phase detector A, and to the other input is a signal from the output of generator 7. The generator 7 is synchronized by an input signal that follows the frequency of the signal from the rotation speed sensor f through the modulator 6. When the input frequency changes, the phase gap between the input signal and the voltage of the oscillator 7 appears. proportional to this deviation. The voltage from the output of the phase detector 4, about the magnitude of the phase shift, is fed to the function converter 5, which 8 adjusts the degree of coupling of the generator 7 to the input signal by acting on the amplitude of the synchronizing signal in the modulator 6 and corrects the non-linear relationship. From the output of the phase detector 4, a signal proportional to the oscillation of the rotational frequency is fed to the recording device 8. Thus, in the device in the entire measurement range, each value of the detuning frequency of the sensor 3 corresponds to a certain degree of synchronization, at which the conversion coefficient remains unchanged. The device measures irregularity of rotational speed over a wide frequency range. The device also provides a linear dependence of the phase on the non-uniformity of the rotation frequency throughout the entire frequency band of the measured frequencies, which improves the accuracy of measuring the non-uniformity of the rotation frequency. The device is used in the study of the dynamics of the torsional circuit of internal combustion engines. Increasing the accuracy of measurements in such studies makes it possible to more accurately determine the optimum operating mode of the engine, which in turn makes the tests more economical and also reduces the testing time.

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Claims (1)

DEVICE FOR MEASURING ROTE VARIABILITY, comprising a generator, a phase detector, a recording device and a rotation speed sensor, the output of which is connected to one of the inputs of the phase detector, the second input connected to the output of the generator, and the output to the recording device, characterized in that, for the purpose of increasing the accuracy of measurement and expanding the dynamic range of measuring the unevenness of the rotation frequency, a functional converter of the detuning of the frequency of the input signal in amplitudes is introduced into it synchronizing signal and a modulator, one input of which is connected via a function generator with the output of the phase detector, _a second input - to the output rotational speed sensor ®, and an output connected to the oscillator input. SU., „1150548