SU348891A1 - ELECTRON-BEAM DEVICE FOR MEASURING VIBRATION OF THE BLADDES OF THE WORKING WHEEL OF THE TURBO-MOTOR - Google Patents

Description

The invention relates to the field of measurement technology.

Basically auth. St. No. 236827 describes an electron-beam device for measuring the vibrations of the blades of the impeller of a turbomachine, comprising an electron-beam tube and three groups of pulse sensors, of which the sensors of the first group are installed near the shaft of the turbomachine and connected to a continuous vertical generator; sensors of the second group are installed near the root sections of the blades and connected to horizontal waiting sweep generator, and sensors of the third group are installed above the peripheral portions of the blades and connected to the modulating grid electron tube.

The proposed device differs from the known that it is equipped with additional sensors installed along the length of the blades and connected through a switch to the modulating grid of the electron-beam tube. This makes it possible to increase the accuracy of determining the oscillation frequency of the blades.

The drawing shows a schematic diagram of the proposed device.

the number of blades 3 and the step is equal to the pitch of the blades. Pulse sensor 4 generates impulse B the moment of passing pin 2 past it. In the case (not shown) of the turbomachine, a pulsed sensor 5j is also mounted above the wheel and the pulse 5 is displaced relative to sensor 4 by a certain angle spinning wheels. On disk I, in addition, another pin 6 is installed, against which a pulse sensor 7 is placed, which, when the pin 6 passes by, passes a pulse that passes through the amplifier 8 and the continuous sweep generator 9 and provides horizontal scanning on the electron-beam tube 10. The I.M. pulse from the sensor 5 is formed into a short positive impulse by the NMR shaper and fed to the modulated grid of the tube 10. This leads to an increase in the illumination of the beam at the moment when the end of the blade 3 is against the sensor 5. And The impulse from the sensor 4 passes through the pulse shaper 12, the delay delay generator 13 and starts the standby sweep generator 14. The output signal of the standby sweep generator 14 is applied to the horizontal deflecting plates of the cathode ray tube 10, causing the beam to not move at a constant speed on the screen, a line drawn vertical lines the number of which is equal to the number of blades 3. When the blade 3 passes under the sensor 5, the line is highlighted in a certain place. If the paddles 3 do not oscillate, then at each turn of the wheel the marks on the screen lie in the same place. When the blades oscillate, the tags at each turn will be placed at different distances from the start of the sweep, as the time interval between the pulses of the sensors 5 and 4 changes. Using the electron-beam tube 10 afterglow, a large number of marks are measured and the distance between two extreme marks, which will be proportional to the swing. Registration is done by camera. Additional sensors 15, 16 are installed at a certain distance x a and b and work the same as

and sensor 5. Switching alternately sensors 5, 15 and 16 using switch 17, you can fix the deflections of the blades 3 in a certain place and thereby present the shape of the curve of deflections, from which you can determine the oscillation frequency.

Subject invention

Electron beam device for measuring the vibrations of the impeller blades of a turbomachine according to ed. St. No. 236827, characterized in that, in order to improve the accuracy of determining the oscillation frequency of the blades, it is equipped with additional sensors mounted along the length of the blades and connected through a switch to the modulating grid of the cathode-ray tube.