RU2030724C1 - Unbalance meter - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: unbalance meter has two vibration sensors 1 and 2, buffer amplifier and integrators 5 and 6, analog-to-digital converter 19 and reading register 21 connected in series. Computer 25, timer 26, permanent storages 28 and 29, on-line storage 30 and unit 31 of control and display are connected in parallel to three wires 24, 23, 22 of control, data and address. Mark sensor 32 is coupled via amplifier 33 directly to computer 25. Clock generator 34 generates clock frequency to computer 25 and timer 26. Computer controls tunable filter 8 and amplifier 14 via control register 27. Meter determines value and angle of unbalance, rotational speed, performs harmonic and spectral analysis of vibration signal, records information in on-line storage, calculates influence coefficients of balancing and correcting masses with single- and multiplane balancing. EFFECT: improved efficiency in determination of unbalance, in measurement and analysis of vibration, in recording and storage of vibration information. 3 cl, 1 dwg

Description

 The invention relates to instrumentation and can be used for balancing rotors, analysis and recording of vibration.

 A device for measuring the imbalance of the rotors [1], containing a computer and connected to it by a number of blocks, a vibration sensor, a tag sensor, an analog-to-digital converter (ADC), an indicator and other elements.

 The known device provides sufficient accuracy in stationary conditions, but gives significant errors when balancing the rotors in operating conditions, when a large number of random and systematic interference distort the imbalance signal measured on the support or rotor housing. In this case, a more subtle analysis of the rotor vibration is required, which the known device is not able to perform.

 The aim of the invention is to increase accuracy when working in non-stationary conditions and expand the functionality of the device.

 This is achieved by the fact that the imbalance meter, comprising a vibration sensor, an ADC, a tag sensor, a clock generator, a control and indication unit and a calculator connected to them, is equipped with a second vibration sensor connected in series with the ADC by a controlled channel selection switch, a buffer amplifier, two integrators, controlled switch, tunable filter, controlled amplifier, normalizer, storage fetch unit. The unbalance meter is also equipped with three buses: address, data and control and a parallel register, read, timer, port, clock, two blocks of read-only memory (ROM), a block of random-access memory (RAM). The calculator and the control and indication unit are connected in parallel to three buses, the clock generator is additionally connected by a timer, the control output of the timer is connected to the sampling and storage circuit and the ADC, the latter is connected to the read register by the output. The control outputs of the control register are connected to a controlled channel selection switch, a controlled switch, a tunable filter controlled by an amplifier. The tunable filter is made in the form of series-connected blocks of the adder, the first code-driven register integrator, the second integrator controlled by the integrator resistor, connected by additional feedbacks from the output of each integrator with additional adder inputs, and the additional inputs of each of the code-controlled resistors connected to the register control lines management. The controlled amplifier is made in the form of a series-connected adjustable resistor and an adjustable amplifier connected by feedback, connecting the output of the adjustable amplifier with an additional input of the adjustable resistor code, and other additional inputs of the regulated resistor code and the adjustable amplifier are connected to the control outputs of the control register.

 The drawing shows a structural diagram of an unbalance meter.

 The imbalance meter contains two vibration sensors 1, 2, which can be of any design, for example, in the form of a piezoelectric, inductive, induction, capacitive or optical sensor. The sensors are connected to a controlled channel selection switch 3, to the input of which a signal of one of the sensors is passed. A controlled channel selection switch 3 is connected to a buffer amplifier 4, which matches the measuring circuit of the device with the characteristics of specific sensors. Integrators 5 and 6 sequentially perform primary and secondary integration of the signal from the sensors. The controlled switch 7 is connected directly to each of the integrators 5, 6 and to the buffer amplifier 4. The output of the controlled switch 7 is connected to the input of the tunable filter 8. The tunable filter consists of series-connected adder 9, the first resistor 10 regulated by code, the first integrator 11, and the second adjustable the code of the resistor 12 and the second integrator 13. In this case, the outputs of the integrators 11 and 13 are connected by feedbacks to the inputs of the adder 9. The output of the tunable filter is connected to the input of the controlled amplifier 14, consisting of a code-controlled resistor 15 and a series-connected adjustable amplifier 16, the output of which is connected via a feedback line to an additional input of a code-controlled resistor 15. The output of the controlled amplifier is connected to the input of the normalizer 17, which is connected in series with the sampling and storage unit 18 and the ADC 19. The ADC 19 is connected by the information bus 20 to the read register 21. The inputs and outputs of the read register are connected in parallel with three data buses 22, addresses 23 and control 24. Similarly with these three buses, a calculator 25, a timer 26, a control register 27, two read-only memory units 28 and 29, a random access memory unit 30, and an indication and control unit 31 are connected in parallel. The imbalance meter also includes a photoelectric or electrodynamic type label sensor 32 connected in series with the amplifier 33 and the calculator 25 and a clock generator 34. The clock generator is connected to the calculator 25 and the timer 26 and can be made on the basis of a 10 MHz crystal oscillator. The output of the timer 26 is connected to the control inputs of the sampling and storage unit 18 and the ADC 19. The outputs of the control register 27 are connected to the control inputs of the controlled switches 3 and 7, regulated by a code of resistors 10, 12 and 15, of an adjustable amplifier 16.

 The unbalance meter operates in the following modes: measurement of the value and angle of unbalance while measuring the speed; two or multi-plane balancing of rotors in their own supports by the test load method or by known influence factors; measurement and analysis of the general level and power of vibration in a given frequency range (harmonic and frequency spectral analysis); recording and storage of measured data on imbalance, vibration and spectra, as well as viewing recorded data and transmitting them through an interface to a personal computer for processing and predicting changes in imbalance and vibration. The choice of the operating mode is set by the display and control unit 31 in accordance with the software embedded in the ROMs 28 and 29.

 The unbalance meter works as follows.

First, in block 31, the operating mode and sensitivity coefficients of one or each of the two vibration sensors 1, 2 are set depending on the imbalance or vibration measurement circuit. Then, through the controlled control register 27, channel selection switch 3, one of the vibration sensors 1, 2 is connected to the measuring circuit of the device. Next, the dimension of the measurement is set: displacement, speed or acceleration, which is determined by switching on the corresponding channel of the controlled switch 7, the control signal to which is transmitted via the control register 27. Then the parameter of the measured signal is set: amplitude, range or rms value, which is implemented by calculator 25 using special programs embedded in ROMs 28 and 29. The clock cycle of the calculator and timer 26 is set by the clock generator 34, then, if the vibration signal is unstable, it turns on gram of averaging embedded in ROM, which allows to increase the accuracy of measuring imbalance, its angle and vibration parameters. When measuring the imbalance in one plane, the signal from the corresponding vibration sensor through the channel selection switch 3 is fed to the buffer amplifier 4 and integrators 5 and 6. Depending on the set dimension, the controlled switch 7 passes the signal either from the buffer amplifier 4 or from one of the integrators 5, 6. Then the signal passes a tunable filter 8, which serves to clean the signal from spurious harmonics of higher orders. The control signals from the computer to the code-controlled resistors 10 and 12 of the filter are supplied through the control register 27 in accordance with the rotor speed and the quantization frequency of the vibration signal. After the tunable filter, the signal is fed to the input of the controlled amplifier 14, the control signals from the calculator 25 to the adjustable amplifier 14 are transmitted via buses 22, 23, 24 and the control register 27. The controlled amplifier 14 provides a constant signal level at its output regardless of the signal level at the input, those. provides automatic tracking of the measured signal level. Further
the signal passes the normalizer 17 with a constant gain and enters the block 18 sampling and storage. At the time of receipt of the pulse from the timer 26, the block 18 stores and stores until the next pulse the instantaneous value of the vibration level. The obtained value of the analog signal of the ADC 19 is converted into a digital code and transmitted via the information bus 20 to the read register 21, which stores the state of the data bus of the calculator 25 and provides a stored signal to this bus. On the data bus, information about the instantaneous value of the imbalance enters the calculator 25 and is processed in accordance with one of the programs recorded in the ROM. The timer 26, depending on the rotor speed, sets the signal sampling time and the period between samples. At the same time, the signal of the label sensor 32 after amplification in the amplifier 33 also enters the calculator 25. This signal is the source for the timer and the calculation of the imbalance angle. The calculator 25 processes the signal from the vibration sensor 1, 2 and, taking into account the information of the tag sensor 32, provides an imbalance value, its angle and rotor speed on the display screen in the display and control unit 31. When using the averaging mode, the calculator 25 gives the average value of the imbalance and its angle by the number of samples. This eliminates the influence of interference and random vibrations from the rotor drive elements, couplings and bearings on the accuracy of determining the imbalance. Then, the rotor with the test load is started and the calculator 25 displays on the display screen the position and value of the correction mass, which must be set in the correction plane to eliminate the imbalance.

 When balancing the rotor in two planes, the unbalance is measured sequentially at the installation site of each of the vibration sensors 1 and 2 and, if the influence coefficients are not known, then two launches with trial weights are carried out. According to the established coefficients in accordance with one of the programs in the ROM 29, the calculator 25 determines the place and value of the correction masses to eliminate the imbalance.

 To determine the sources of vibration of the rotor and determine the subharmonic components of vibration that affect the determination of imbalance, the calculator 25 performs the calculation and construction on the display screen of the harmonic spectrum of the vibration signal.

 For a detailed analysis of the vibrational state of the rotor or other object under study, the calculator 25 performs the calculation and construction on the display screen of the frequency spectrum of the vibration signal. In this case, the tag sensor 32 is turned off and the calculator 25 performs analytical actions only on the signal of the clock generator 34.

 Any information issued by the calculator 25 (imbalance characteristics, vibration, spectra) can be recorded in RAM 30 by a command from block 31 and stored under its frame number for an arbitrarily long time. This information can be called up by the frame number on the display screen for viewing, and can also be transmitted via the interface to a personal computer for statistical processing, predicting the vibration state of the object, storing data and printing on paper to generate documents about the results of balancing and vibration diagnostics. Selectively, information frames may be erased if necessary.

 Thus, due to the use of elements controlled by the remote control and the calculator, the unbalance meter is automatically tuned to the measured signal and therefore has higher accuracy and noise immunity in the conditions of non-stationary operation of the meter, as well as has wider functionality for measuring vibration, performing harmonic and spectral analysis, accumulating and storage of experimental results. This technical solution provides a change and expansion of the meter functions by software without changing the structure of the meter and its elements.

Claims (3)

 1. UNBALANCE METER, comprising a vibration sensor, an analog-to-digital converter, a tag sensor, a clock, a control and indication unit, and a calculator, characterized in that it is equipped with a second vibration sensor connected in series with a controlled channel selection switch, a buffer amplifier, the first and second integrators, switch-controlled, tunable filter, controlled by amplifier, normalizer and sample and storage unit, timer, amplifier, read register, first and second constantly -memory devices, random access memory, control register, address bus, data bus and control bus, the first and second vibration sensors are connected to the first and second outputs of the controlled channel select switch, the second and third inputs of the controlled switch are connected respectively to the second outputs of the buffer amplifier and the first integrator, the output of the sampling and storage unit is connected to the input of an analog-to-digital converter, the output of which is connected to the input of the read register, the second inputs are The sample and storage and analog-to-digital converters are connected to the first output of the timer, the input of which is connected to the first output of the clock generator, the tag sensor, amplifier and calculator are connected in series, the second input of the calculator is connected to the second output of the clock generator, the first, second, third, fourth , the fifth and sixth outputs of the control register are connected respectively to the third input of the controlled channel selection switch, the fourth input of the controlled switch, the second and third inputs are tunable filter, the second and third outputs of the controlled amplifier, the first, second and third groups of inputs and outputs of the calculator, timer, read register, first and second read-only memory devices, random-access memory, control and display unit and control register are connected respectively to the bus addresses, data bus and control bus.  2. The meter according to claim 1, characterized in that the tunable filter is made in the form of a series-connected adder, a first code-controlled resistor, a first integrator, a second code-controlled resistor and a second integrator, the output of which connected to the first input of the adder is the output of a tunable filter , the first input of which is the second input of the adder, the third input of which is connected to the output of the first integrator, the second and third inputs of the tunable filter are respectively the second the moves of the first and second code-controlled resistors, and the output of the tunable filter is the output of the second integrator.  3. The meter according to claim 1, characterized in that the controlled amplifier is made in the form of series-connected code-controlled resistor and amplifier, the output of which, which is the output of the controlled amplifier, is connected to the first input of the code-controlled resistor, the second input of which is the first input of the controlled amplifier, the second and third inputs of which are respectively the third input of the resistor controlled by the code and the second input of the amplifier.