SU1415192A1 - Device for measuring fluctuations of shaft rotational speed - Google Patents

Abstract

The invention relates to measurement technology and automation. The purpose of the invention is to expand the functionality by determining the instability of the speed of rotation of the shaft within a turn. During the measurement process, the selector 2 selects the time interval between the selected marks of the speed pulse sensor 1 associated with a particular shaft sector. With the help of extremes 8-9, the limiting values of the time interval are determined. The extremators are connected to it by a counter 5 connected to the output of the key circuit 3 of coincidence of the pulses of the period selector and the generator of the reference frequency. 2 Il.

Description

The invention relates to measurement technology and automation and can; be used to measure fluctuations in the speed of rotation of the motor shaft: tel.

; The purpose of the invention is to expand the functionality of: chonal possibilities by determining the non-uniformity of the rotation of the shaft within a revolution.

, FIG. 1 A block diagram of the device is presented .; in fig. 2 - the time diagram of the work of the selector .. period. The device contains a pulse sensor 1 speed, selector 2 period, the key scheme 3 matches, ge; reference frequency generator 4, counter 5, control unit 6, inverter 7, j maximum extremator 8 and extremer I minimum value 9, inverter I torus 10, minimum indication circuit 11; and the circuit 12 for indication of maximum values: a binary p-bit. counter 13, blocks 14 and 15 keys, a matching circuit 16–18, a shaper 19 reset pulses and an RS flip-flop 20. The device works as follows.

Labels are placed on the surface of the motor shaft evenly around the circumference, during the passage of which the speed sensor 1 produces short electrical impulses. The sequence of pulses from the output of the sensor enters the selector 2 periods. The period selector is a trigger circuit, which is outputted by a pulse from one label, and reset by a pulse from another label. The numbers of the corresponding labels are selected by the operator before starting the measurements.

A pulse generated by the selector arrives at the key circuit 3 of coincidence and permits the passage of reference frequency pulses from generator 4 to the input of counter 5. At the same time, the counter records the number proportional to the time interval corresponding to the passage of the sector enclosed between the selected marks under the speed sensor . At the end of the selector pulse, the control unit generates a command by which the specified number is written to the extremator 8 maximum values and the inverse value of the number to the extremator 9 minimum values, and then the second command, which is used to reset the counter 5. Extreme conditioners

-

5 0 5

O r o

five

five

displayed by the display circuits 11 and 12.

Since the process is repeated many times, the extremes 8-9 determine the maximum and minimum values of the duration and period of the pulse of the selector during an arbitrary measurement time. In order to obtain the minimum values of the extremor circuit 9, an inversion operation is performed with respect to the limit value using inverters 7 and 10.

In the selector 2, the counter 13 and the circuit 16 of the match with the block 15 of the keys on the input is a divider on which the division factor is set equal to the total number of labels, and each binary number on the output of the counter 13 corresponds to a certain label,

FIG. 1 shows the position of the keys when the number of labels is 10, the Operator closes the keys of the first and third bits. Counter 13 operates with a tag count of 10. The appearance of signals (1p-4p) at the input of the circuit 16 on the second and fourth bits leads to the appearance of a single level at the output of the circuit and the counter 13 is reset to zero, the trigger 20 is set to one, the input level is set to zero. matching circuit 17 and unit level at the third input of circuit 1-8.

A matching circuit 17 with an input key block 14, a matching circuit 18 with a reset pulse shaper 19 and a trigger 20 are a unit for forming a measurement period allowing measurement of pulse parameters in a sequence defined by only two selected marks. In this case, the number of the selected label is dialed with the keys of the block 14.

The position of the keys in Fig. 1 corresponds to the selection of the fifth mark and to it followed to form the measured period, the keys of the first and third bits are closed. At the output of the circuit 17, U. pulses appear at code numbers 5 and 7 at its input. On the trailing edge of the first of these pulses, shaper 19 produces a pulse iff, p "and a flip-flop 20 is reset, which will enter at the third input of circuit 18 to coincide 314

SRI signal and the prohibition of the receipt of all subsequent pulses in the cycle to the input of the selector circuit 2. At the output of the period selector 2, a pulse Ugyj is formed,

Sequential change of labels along a circumferential shaft and their selective interrogation in the course of measurement make it possible to estimate the circulating pulsations of the velocity of the object under study without calculating its nominal value.

Claims (1)

Formula Eteni A device for measuring fluctuations in the speed of rotation of the shaft, comprising a pulse speed sensor, a serially connected reference frequency generator, a key coincidence circuit, a counter and a control unit, the input of which is connected to the key input of the key circuit and the output of the counter control input, characterized in that , in order to extend the functionality by determining the unevenness of the shaft rotation within the limits of revolution, a selection of 2 is introduced a period torus including a binary n-bit counter, the counting input of which is connected to a pulse speed sensor, and the outputs are bitwise connected via the nepsbrfi key block to the inputs of the first coincidence circuit, and through the second key block to the inputs of the second coincidence circuit, the output of which - is connected with the R-input of the binary counter and the S-input of the RS flip-flop, the output of the first coincidence circuit is connected to the first input of the third coincidence circuit, the output of which is connected to the second input the first bit of the binary counter, to the third input is the output of the RS flip-flop, to the output through the shaper of reset pulses, the R-input of the RS flip-flop, also the matching circuit, In this way, the output of the control unit is connected to the input parallel circuits consisting of an extremator and a maximum value indicator. From an extremer and inverter and display circuit the minimum values, the input of the maximum value extremer is connected to the output of the counter directly, and the input of the minimum value extremator through the second inverter. I II I I I I I 1 / n V. (rorp. reservations VcS. ig. Z