SU1742728A1 - Device for measuring shaft revolution rate - Google Patents

Abstract

Using the measurement of the speed of rotation of the shafts of rotary machines The essence of the invention is a device containing two gaps (1 and 2), two high-voltage coils (4 and 5), two controllable switches (6 and 7), a power source (8), two photodetectors

Description

The invention relates to measuring equipment, and in particular to devices for measuring the speed of rotation of the shaft of hydraulic, electrical and other rotary machines.

A device for measuring the speed of rotation of the shaft is known, comprising a modulator mounted on the shaft with holes, a radiation source and two photodetectors connected to a differential amplifier, the inverting and non-inverting outputs of which are connected to the recorder, one of the photo-receiving devices installed opposite the radiation source, and the other opposite the jumper between the holes of the modulator.

The disadvantages of the known devices are low reliability and noise immunity, as well as the need to install a modulator with holes on the shaft.

The closest in technical essence to the proposed is a device for measuring the speed of rotation of the shaft, containing a modulator mounted on the shaft with holes, two radiation sources mounted opposite the photodetectors. which are connected to a differential two-channel amplifier, the inverting and non-inverting outputs of which are connected to the recorder and two controlled current generators, the inverting output of the differential amplifier connected to the controlled input of the first generator, the output of which is connected to the second radiation source, and the non-inverting output to the controlled input of the second current generator connected by the output to the first current source.

The known device is characterized by insufficient reliability and reliability in the conditions of operation of vehicles. The disadvantage is also limited operational capabilities, since before measuring the shaft rotation speed it is necessary to stop the machine, fix its modulator with holes on the shaft.

The purpose of the invention is the expansion of operational capabilities.

The goal is achieved by that. that in the device for measuring the speed of rotation of the shaft, containing two photodetectors connected to a two-channel amplifier, a registrar and two generators, and the outputs of the amplifier are connected to the inputs of the registrar, two comparators, an RS-trigger and two arresters are introduced, with the arresters and photodetectors located in the same plane , the axes of the arresters and the optical axes of the photodetectors are oriented in radial directions relative to the common center, the arresters are installed at an angle “1 to each other, equal to the angle between the photodetectors, which e are shifted relative to the arresters by an angle of a ₂ , the generators are made in the form of controlled pulsed high voltage sources and connected to the dischargers, the amplifier outputs are connected via comparators to the corresponding inputs of the RS flip-flop, the outputs of which are connected to the control inputs of the high voltage pulsed sources, and the angles hell and and _{2 are} respectively equal where K, P and η are integers satisfying the inequality η>K> P.

The drawing shows a diagram of a device for measuring the speed of rotation of the shaft.

The device contains the first 1 and second 2 arresters located in the immediate vicinity of the rotating shaft 3, generators containing high-voltage coils 4 and 5, controlled keys 6 and 7 and a power source 8. Dischargers 1 and 2 and high-voltage coils 4 and 5 are connected to a power source 8 through controlled keys 6 and 7 and are installed at an angle he = = (K + 2 ^- ) ^- p; - where K and η are integers, and K <n In the direction of rotation of the shaft (indicated by the arrow) with an angle shift of « ₂ = (P - tg) --- where P is an integer.

Z and with P <K., the pedestal 9 and second 10 photodetectors are installed, connected to a two-channel amplifier 11. The first and second outputs of which are connected to the recorder 12.

In addition, the first output of the two-channel amplifier 11 is connected through the first comparator 13 to the S-input of the trigger 14. whose inverse output is connected to the key 7. and the second output of the two-channel amplifier is connected through the second comparator 15 to the R-input of the trigger 14, the main output of which is connected to key 6. To turn on the device into operation, normally open contacts 16 and 17 are installed in parallel with controlled keys b and 7. To ensure stable operation of the device, the shaft 3 of the machine is connected by a plate 18 to a common grounded wire of the device. Heat marks 19 are formed on the surface of the shaft 3.

The device operates as follows.

about

When the shaft 3 rotates clockwise (indicated in the diagram), the power supply 8 is turned on. Let the trigger 14 in the initial state be in a stable state, which corresponds to the presence of signal 1 at the main output of the trigger and the absence of signal O at the inverse output. In this case, the managed key 6 is in the open state, and the managed key

- in the closed state. The current from the power source passes through the public key 6 and the first high-voltage coil 4. Energy is accumulated in the electromagnetic field of the coil 4. High voltage coil 5 is de-energized at this time. Normally open contacts 16 and 17 are closed, and the current from the power source 8 passes through a high-voltage coil 5, in the electromagnetic field of which energy is also accumulated. Coils 4 and 5 are ready to go.

The contacts 16 and 17 are disconnected. In this case, there is no change in the operation of the coil 4, since the key 6 remains open, and the power supply circuit of the coil 5 is broken and a high voltage self-induction EMF appears on the terminals of the high-voltage coil 5, which breaks the discharge gap between the spark gap 2 and shaft 3, since the circuit of the high-voltage coil 5 is closed through the discharge gap and plate 18 to a common grounded wire of the device. As a result of the spark slipping on the shaft 3, the first heat mark 19 occurs.

When the shaft 3 is rotated through the angle "2 = (P-

360 ⁰

- o) ---- (in the diagram η = 6. P = 1) the thermal 'η tag 19 is located opposite the photodetector 10. Photodetector 10 receives the radiation from the heat tag 19. The signal from the photodetector 10 is fed to the second input of the two-channel amplifier 11 and amplified. From the second output of the amplifier 11, the signal through the comparator 15 is fed to the R-input of the trigger 14. The trigger 14 goes into a stable state, in which the signal at the main output will be absent (0). and a 1 ”signal appears at the inverted output. As a result, the key 6 is closed, and the key 7 is opened.

When the key 6 is closed, the power circuit of the high-voltage coil 4 is opened and a high voltage self-induction EMF appears on the terminals of this coil, which breaks the discharge gap between the first spark gap 1 and shaft 3. since the slot of the high-voltage coil closes through the discharge gap and plate 18 to a common grounded wire of the device .

As a result of the slip of the spark on the shaft 3, the next second heat mark 19 occurs, located from the first at an angle of "1 + ar.

When the shaft 3 is rotated through an angle a = (P1 _λ 360 °

- 2) —-— the second thermal mark is located opposite the photodetector 9. The photodetector 9 receives the radiation from the thermal mark 19, the signal from the photodetector 9 is fed to the first input of the amplifier 11 and amplified. From the first output of the amplifier 11, the signal through the comparator 13 is fed to

S-input of the trigger 14. In this case, the trigger 14 goes into a stable state, in which signal 1 appears at the main output, and the signal disappears at the inverse output (0). As a result, the key 7 is closed, and the key 6 is opened. A spark jumps between the spark gap 2 and the shaft 3 and a heat mark 19 appears, shifted relative to the first mark by an angle a \ - ay. With further rotation of the shaft 3, the process of applying heat marks 19 continues. until all η marks are applied, and during operation of the device, heat marks are restored before each location opposite the corresponding photodetector 7.

To measure the speed of rotation of the shaft 3, the signals from the first and second outputs of the two-channel amplifier 11 are fed to the input of the recorder 12. From which there is a function;

Claims (1)

Claim A device for measuring the speed of rotation of the shaft, containing two photodetectors. connected to a two-channel amplifier, a recorder and two generators, and the outputs of the amplifier are connected to the inputs of the recorder, characterized in that, in order to expand operational capabilities, two comparators are introduced into the device. RS-trigger and two arresters. moreover, the arresters and photodetectors are located in the same plane, the axis of the arresters and the optical axes of the photodetectors are oriented in radial directions relative to the common center, the arresters are installed at an angle ay to each other, equal to the angle between the photodetectors, which are offset relative to the arresters by an angle a. the generators are made in the form of controlled high-voltage pulsed sources and are connected to the arresters, the amplifier outputs are connected via comparators to the corresponding inputs of the RS trigger. the outputs of which are connected to the control inputs of the pulse sources 742728 of high voltage, and the angles hell and _<v h 360 ° "2 are respectively equal (K + - ^and 1 360 θ (P -) ———, where K. Rip are integers satisfying the inequality n> K> P.