RU114527U1 - DEVICE FOR FORECASTING THE TECHNICAL CONDITION OF THE INTER-ROTOR BEARING OF THE AVIATION GAS-TURBINE ENGINE IN OPERATION - Google Patents

Abstract

A device for predicting the technical state of an inter-rotor bearing of an aircraft gas turbine engine in operation, containing a vibration sensor and an electronic device, characterized in that an indicator installed in the cockpit is used, and the electronic device is equipped with a vibration process spectrum calculator by means of a fast Fourier transform (FFT), with a connected output by flash memory, a block of tuning data, containing the values of rotation frequencies, amplitudes of vibration velocities for a high-pressure rotor (HPR), an inter-rotor bearing separator, an amplitude of vibration velocity for a low-pressure rotor (LPR), a boundary vibration velocity of the separator, coefficients Krnd, Krvd, determined based on geometric dimensions of various types of bearings for calculating the cage speed; the following blocks connected to its outputs by inputs: the unit for identification of the frequency of rotation of the high-pressure rotor (HPR) in the spectrum of the measured vibration process with the calculated value of the frequencies Frvd. calc. ± Δf and comparison of vibration velocity with the calculated value; rotation speed identification unit (ICH) of the inter-rotor bearing cage in the spectrum of the measured vibration process with the calculated frequency value Fsep. calc. ± Δf and comparison of vibration velocity with the calculated value; the unit for identification of the frequency of rotation (ICH) of the low pressure rotor (RND) in the spectrum of the measured vibration process with the calculated identified value of the frequency Frnd. calc. ± Δf and comparison of vibration velocity with the calculated value; a unit for comparing the actual value of the vibration speed of the separator with the boundary level of the vibration speed of the separator; block calculation

Description

The utility model relates to vibrational monitoring of the technical condition of inter-rotor (shaft-to-shaft) rolling bearings of two-shaft aircraft gas turbine engines in operation.

A known method for predicting the technical condition of rolling bearings, in which a vibration sensor is installed in the cavity of the inner rotor shaft in the region of the shaft bearing. The inner rotor shaft is rigidly fixed in the circumferential direction, the outer rotor shaft is untwisted to the specified rotation frequencies, the spectrum of vibration signals is measured and the resonant frequencies are determined. After stopping the outer shaft, repeated measurements are made in two or more circumferential positions of the inner rotor shaft and the technical condition of the bearing is evaluated. When conducting repeated measurements, the vibration sensor is moved together with the internal shaft, while the vibration sensor is selected above and below the horizontal plane of symmetry passing through the axis of rotation of the internal shaft. In each of the circumferential positions of the shaft, the vibration amplitude of the vibration sensor corresponding to the resonant frequency is determined, then the largest of all the amplitudes is selected. By the position of the vibration sensor relative to the horizontal plane of symmetry of the inner shaft corresponds to this greatest value, judge the technical condition of the bearing. If the largest amplitude value corresponds to the position of the vibration sensor below the horizontal plane of symmetry of the inner shaft and does not exceed the maximum permissible value, the forecast of the technical condition of the bearing is positive, if the largest amplitude corresponds to the position of the vibration sensor above the horizontal plane of symmetry of the internal shaft, the forecast is negative (RU, 2238532, G01M 13 / 04, 2002).

The disadvantage of the above method is that such measures for rejecting defective bearings are possible under special conditions when labor-intensive work is carried out on a bench with a vibration sensor installed in the cavity of the inner rotor shaft in the region of the shaft bearing. To assess the technical condition of the bearing in operation, this method is not practicable.

A known method for the diagnosis of inter-shaft rolling bearings of twin-shaft turbomachines by measuring the vibration of the outer casing and determining resonant frequencies, in which the shaft is preliminarily unwound to measure the harmonics of the frequency of the rolling elements of the bearing, the rotation drive is turned off, one of the turbomachine shafts is rotated by an angle where z is the number of rolling elements of the bearing, n = 1, 2, 3, and is fixed, in each angular position of this shaft, another shaft is untwisted to a rotation speed at which the previously measured harmonics of the frequency of repetition of the rolling bodies coincide with the resonant frequency of the outer casing of the turbomachine at the installation site vibration sensor, and turn off the drive, at the beginning of free rotation, measure the average value of the vibration of the outer casing, which is taken as the threshold level for the set angular position when the condition of the bearing is determined by the technique conditions, then during free rotation until the shaft stops, the average value of the amplitudes is measured, the number and repetition rate of the pulsed vibration signals of the outer casing exceeding the threshold level, then the shaft is installed and fixed in a different angular position and the measurement is repeated according to the measured average value of the amplitudes, the number of and the repetition rate of pulsed vibration signals by comparison with threshold values judge the presence of a defect (SU, 1807770, A1 01M 13/04, 1996).

The disadvantage of the above method is the complexity of the procedure for measuring the harmonics of the frequency of the rolling elements of the bearing and limited ability to determine the defect due to the use of the average level of vibration obtained after determining the defective zone using a band-pass filter.

A device is known that includes a vibration sensor mounted on the outer casing of a controlled mechanism on board an aircraft, measured during the rotation of one of the rotors on the coast. The defective zone is determined according to the forecasting results in two stages, a diagnostic model is formed at the first stage, and the technical condition of the bearing being diagnosed from the family of dependences of average values of vibration amplitudes on operating time is predicted using this model, while the average value of vibration signal amplitudes is measured at the first stage, spinning the shaft to a speed at which frequencies higher than the resonant frequency of the outer casing with the vibration sensor are excited, then the drive is turned off and measured as indicated value for slowing the shaft rotates at a predetermined rotational speed range. RU 2013756.G01M 13/04 1994.

However, forecasting is complicated by the fact that obtaining a diagnostic model consisting of a family of dependences of average values of vibration amplitudes on operating time in the form of curves, the nature of which depends on the initial state of the bearing units and requires a set of statistics and time-consuming data. In addition, vibration control is carried out according to the average vibration level without revealing the diagnostic frequencies of the bearing, which reduces the reliability of assessing its condition.

A known method for detecting defects of shaft bearings of double-circuit gas turbine engines (GTE), manifested in increased vibration on the coast of the rotors. The problem is solved in that the vibrometer containing the vibration sensor, the electronic unit and the recorder is equipped with an additional amplifier. It is proposed to use an aircraft on-board recorder of the "Tester UZ" type or a magnetic aircraft registrar of parameters of the "MSRP" type as a registrar. When registering vibration on the coast, there is the advantage that when reducing the speed of the gas turbine engine from the workers to the complete stop of the rotors, the strong vibration components that are caused, for example, by gas-dynamic noise, rotor imbalance, etc., decrease faster and the vibration is weaker than in particular, shaft bearings caused by incipient defects in rolling elements and rings appear without interference. Various defects have their own coasting speed (SU, 2073224, G01M 13/04).

The disadvantage of the above method is the difficulty of choosing the amplitude characteristic (AX) of the vibrometer with variable slope, providing registration on the coast of a weak signal.

The technical result, which the utility model aims to achieve, is to increase the reliability of predicting the state of the inter-rotor (shaft-to-shaft) bearing, to determine the presence of a defect in the bearing elements and to increase the flight safety of shunting aircraft in operation.

To achieve the named technical result, an indicator installed in the cockpit is introduced into the device for predicting the technical condition of the inter-rotor bearing of an aircraft gas turbine engine in operation containing an electronic device, a vibration sensor, and the electronic device is equipped with a vibration spectrum calculator by means of a fast Fourier transform (VSB), with to its output flash memory, a block of tuning data, comprising: values of rotational frequencies, amplitude of vibration velocities for otorrhea high pressure (RVD) separator mezhrotornogo bearing vibration amplitude for the low-pressure rotor (RND), the boundary vibrovelocity separator Krnd coefficients Krvd calculated based on the geometrical dimensions of different types of bearings for calculating the speed of the separator; the following blocks connected to its outputs by inputs: unit for identifying the frequency of rotation (IAS) of the high pressure rotor (RVD) in the spectrum of the measured vibration process with the calculated frequency value Frvd calc. ± Δf and comparing vibration velocity with the calculated value; the unit for identification of the rotational speed (IAS) of the inter-rotor bearing cage in the spectrum of the measured vibration process with the calculated frequency value Fcen. calc. ± Δf and comparing vibration velocity with the calculated value; a unit for comparing the actual value of the separator vibration velocity with an acceptable level of separator vibration velocity; unit for identifying the frequency of rotation (IAS) of the low pressure rotor (RND) in the spectrum of the measured vibration process with the calculated identified frequency value Fpн calc. ± Δf and comparing vibration velocity with the calculated value; the unit for calculating the identified rotational speed Fpnd of the low-pressure rotor of the RND in test mode from the algorithm:

Fcen = Krvd * Ff.rvd + Krnd * Ff.rnd, (1)

connected by the two first outputs of the IAN blocks of the RVD rotor, separator by identifiable frequencies Ffact. RVD, Fact. sep. with the inputs of the block calculating the speed of the RND. At the same time, the vibration sensor is built into an electronic device located on the engine casing, the output of the vibration sensor is connected to a series-computed calculator of the BCB, the ICH unit of the rotor of the high pressure hitch in the spectrum of the measured vibration process with the calculated frequency value Frvd calculation. ± Δf, and comparing the vibration velocity with the calculated value of Vrvd. fact. ≥ Vrvd. calculation connected to the second output for exceeding vibration velocity -Vrvd. calculation to the first normally open switch (P1) connecting the output of the BCB unit to the input of the IHD block of the inter-rotor bearing separator in the spectrum of the measured vibration process with the calculated frequency value Fcen. calc. ± Δf, and comparing the vibration velocity with the calculated value of Vsep. fact. ≥ Vrvd. calculation, the second output of which exceeds the calculated vibration velocity Vrvd. the calculation is connected to the second normally open switch (P2) connecting the output of the BCB with the input of the IHD block of the RND rotor in the spectrum of the measured vibration process with the calculated identified frequency value Fpн calc. ± Δf and comparing the vibration velocity with the calculated value of Vpnd fact.≥. Vpnd calculation, the output of the IIN block of the RND rotor for exceeding the vibration velocity - Vpnd calculation is connected to the third normally open switch (P3) connecting the IHD block of the separator of the rotor bearing with the third output according to the actual vibration speed of the separator with the input of the unit for comparing the actual vibration speed of the separator with the acceptable level of the separator’s vibration velocity, .sep ≥ Vsep.top, the output of which is connected to the fourth normally open switch (P4) connecting the on-board power supply to the indicator: “dangerous vibrations are inter-rotor th bearing ”(0 V MCI), and the electronic device is connected to the on-board power source via a push-button push-button“ Control ”in the cockpit at a given RPM speed.

New is the fact that the proposed device for monitoring the condition of the inter-rotor bearing provides identification of the specified diagnostic frequency in the broadband signal of the vibration process (without using standard channels for measuring the rotor speed) and gives a message about the technical condition of the inter-rotor bearing before each flight of the aircraft, and this improves flight safety aircraft in operation.

In addition, the utility model does not require a special placement on the engine housing and has a built-in flash memory for recording the calculated spectrum values.

The proposed utility model is illustrated by the following figures:

Fig. 1 is a block diagram of a utility model;

figure 2 shows a General view of a utility model;

figure 3 presents the spectrogram of the vibration process obtained during normal operation of the rotor bearing, which shows the vibration velocity at frequencies of rotation Frvd-14, Fcen-15, Frnd-16;

figure 4 presents the spectrogram of the vibration process obtained during the development of the defect in the inter-rotor bearing, which shows the vibration velocity at frequencies of rotation Frvd-14, Fsep-15, Frvd-16.

To clarify the essence of the utility model, Figs. 1, 2 show a general view and a block diagram of the proposed device for predicting the technical condition of the rotor bearing of an aircraft gas turbine engine in operation, which shows: a vibration sensor 1 built into the device, a vibration spectrum calculator by means of a fast Fourier transform (VSB ) 2, with a flash memory 8 connected to its output, a tuning data block, comprising: values of rotation frequencies, amplitudes of vibration speeds, coefficients Krnd, Krvd for calculation separator rotation frequency, permissible separator vibration velocity 3; The following blocks connected to its outputs are as follows: the ID block for identifying the speed of the WFD in the spectrum of the measured vibration process with the calculated frequency value Frvd calc. ± Δf, and comparing vibration velocity with a calculated value of 4; unit for identifying the rotational speed of the inter-rotor bearing cage in the spectrum of the measured vibration process with the calculated frequency value Fsep. ± Δf and comparing vibration velocity with a calculated value of 5; a unit for comparing the current value with a boundary level of vibration velocities of the separator 9; RND rotation frequency identification unit in the spectrum of the measured vibration process with the calculated frequency value Fpн calc. ± Δf and comparing vibration velocity with a calculated value of 6; block calculation of the identified speed of the RND in test mode 7 according to the algorithm:

Fasch.rnd = (Ff.sep-Krvd * Ff.rvd) / Krnd, (2)

associated with the first outputs of the comparison blocks of the WFD 4 and the separator 5 by identifiable frequencies, respectively, F.f.rvd and Ff.sep ,. In this case, the output of the vibration sensor 1 is connected to a series-connected calculator of the spectrum of the BCB 2, the IHD block of the rotor of the HPH in the spectrum of the measured vibration process with the calculated value of the frequencies Frvd calculation ± Δf, and the comparison of the vibration velocity (Vf.rvd≥Vcalc.) With the calculated value 4, connected to the second the output exceeding the calculated vibration velocity to the switch (P1) connecting the output of the BCB 2 unit to the input of the ICH unit of the inter-rotor bearing separator in the spectrum of the measured vibration process with the calculated frequency value Fcen. calculation ± Δf and comparing the vibration velocity with the calculated value (Vph.sep≥Vcalc) 5, the second output of which, when the calculated vibration velocity is exceeded, is connected to a switch (P2) that connects the BCB 2 output to the input of the RND speed identification block in the spectrum of the measured vibration process with the calculated identified value of frequencies Fpн calc. ± Δf Hz and comparing the vibration velocity with the calculated value (Vf.rnd≥Vcalc) 6. The output of the IHD block of the RND 6 rotor when the vibration velocity is exceeded is connected to the switch (P3) connecting the IHD block of the separator of the rotor bearing 5 with the third output of the actual separator vibration velocity with the input of the block comparing the actual vibration speed of the separator with the boundary level of the speed of the separator, (Vf. Sep≥Vcen. add) 9, the output of which is connected to a switch (P4) connecting the on-board power supply to the indicator: “ОВ МРП” 10. The BCB is connected to the flash memory 8 for registration of the calculated spectrum values.

Figure 2 shows the electronic device 12 connected via a push-button push-button “Control” in the cockpit 11 to the on-board power supply 27 V. The output of the block 9 of the electronic device 12 is connected to a normally open switch (P4) connecting the on-board power supply to the indicator 10 : “OW MRP”.

The device operates as follows.

To predict the technical condition of the inter-rotor bearing of an aircraft gas-turbine engine in operation, a small-sized device is installed on the engine casing that allows to warn of a defect in the inter-rotor bearing in real time during operation.

A device for predicting the technical condition of the inter-rotor bearing of an aircraft gas turbine engine is in working condition during the period of turning on and holding the button of the “Control” push button in the cockpit at a given rotational speed of the RVD 11 rotor.

Before pressing the button 11, the pilot must set the set frequency of rotation of the high-pressure rotor exactly according to the index. Setting the preset speed of the high pressure hitch is a sign (command) to start the operation of the device.

The push-button switch 11 is turned on for a period of 5 ... 10 seconds before takeoff or after landing, as well as when checking the vibrational state of the engine during ground work.

The engine operating mode is selected in which there is no coincidence of the diagnostic frequency, for example, of the separator with the combination and aggregate frequencies, for which the calculated values of the RPM speed of the separator in the specified range of frequencies and vibration velocities, the boundary value of the vibration velocity for separator 5, are entered into block 3 first, for RND - vibration velocities, as well as coefficients (Krvd, Krnd) for the algorithm of block 7. After setting the specified frequency of rotation of the high-pressure rotor, the “button” is pressed exactly according to the pointer warning light "11 for 5 ... 10 seconds. In this case, the vibration process is processed from the vibration sensor 1, the signal is converted, followed by the calculation of the spectrum of the vibration process in block 2 (BCB) and its storage in block 8. Then, in block 4, the rotational speed of the high pressure rotor (WFD) is identified in the spectrum of the measured vibration process with calculated frequency values Frvd races. ± Δf and compares the vibration velocity (V actual.rvd≥Vcalcul. Rvd). If Vact.rvd≥Vcalc.rvd, then the switch (P1) connects the output of the BCB 2 with the input of block 5 to identify the rotational speed of the inter-rotor bearing cage with the calculated value Fcen.calc. ± Δf. If V actual separator ≥ V separator calculation, then the switch (P2) connects the output of the BCB 2 with the input of block 6, which identifies the speed of the RNR Ract.rnd in the spectrum of the measured vibration process by the calculated value of the frequency Fcal.rnd ± Δf defined in block 7 according to the following algorithm (2):

Frach. rnd = (Ff. sep-Krvd * Ff. rvd) / Krnd, (2)

and a comparison is made in the spectrum of the measured vibration process of the magnitude of the vibration velocity (Vact.rnd≥Vcal.rnd).

After determining the actual speed of the RND and the vibration velocity Vpnd fact. from the spectrum of the vibratory process BCB 2, provided - Vpnd fact. ≥Vpnd calculation, the switch (P3) connects the output according to the vibration velocity -Vfak.sep. from block 5 with the input of block 9, which compares the level of vibration at the rotational speed of the separator of the inter-rotor bearing of block 5 with the permissible value of the vibration of the separator coming from block 3 (Vfax Sep.V Sep.add.). If the specified boundary vibration level Vcen-dop is exceeded at the separator speed, the switch (P4) connects the on-board power supply to the indicator: “ОВ МРП” 10.

In addition, the registered information in block 8 can be rewritten from the device for measurements both during normal operation of the inter-rotor bearing, see Fig. 3, and upon detection of a defect in the inter-rotor bearing, see Fig. 4, which shows spectrograms of the engine vibration process at rotational speeds Frvd-14, Fcen-15, Frnd-16.

When checking the engine, an alarm is issued that the limit value of the vibration level has been exceeded at the rotational speed of the inter-rotor bearing cage, which indicates a defect in the inter-rotor bearing, in which it is necessary to go to a reduced engine operation mode with subsequent inspection.

Thus, the proposed device identifies the components in the spectrum of the vibration process, without the use of standard channels for measuring rotor speeds; reveals the specified diagnostic frequencies of the rotor bearing elements, for example, the speed of the separator during engine operation by measuring and calculating taking into account the geometry of each type of bearing and comparing the measured vibration velocities with acceptable values on the diagnostic frequency of the rotor bearing, gives an alarm about the technical condition of the rotor bearing before each flight LA

Claims (1)

A device for predicting the technical condition of the rotor bearing of an aircraft gas turbine engine in operation, containing a vibration sensor and an electronic device, characterized in that the indicator is installed in the cockpit, and the electronic device is equipped with a spectrum calculator of the vibration process by means of a fast Fourier transform (BCB), connected to it output with flash memory, a tuning data block containing values of rotation frequencies, vibration velocity amplitudes for a high pressure rotor I (RVD), the inter-rotor bearing cage, the amplitude of the vibration velocity for the low pressure rotor (RND), the boundary vibration speed of the cage, the coefficients K _rnd , K _rvd , determined on the basis of the geometric dimensions of various types of bearings to calculate the speed of the separator; the following blocks connected to its outputs by inputs: unit for identifying the frequency of rotation (IAS) of the high-pressure rotor (RVD) in the spectrum of the measured vibration process with the calculated frequency value F _{rvd. calc.} ± Δf and comparing vibration velocity with the calculated value; unit for identifying the frequency of rotation (IAS) of the inter-rotor bearing cage in the spectrum of the measured vibration process with the calculated frequency value F _{sep. calc.} ± Δf and comparing vibration velocity with the calculated value; unit for identification of the rotational speed (IAS) of the low pressure rotor (RND) in the spectrum of the measured vibration process with the calculated identified value of the frequency F _{rnd. calc.} ± Δf and comparing vibration velocity with the calculated value; a unit for comparing the actual value of the separator vibration velocity with a boundary level of the separator vibration velocity; the unit for calculating the identified rotational speed R _rnd of the low-pressure rotor RND in test mode according to the algorithm: F _{rnd. calc.} = (F _f.sep -K _rvd · F _f.rvd ) / K _rnd , connected by two inputs with the outputs of the first outputs of the blocks of the IAS of the rotor of the high pressure separator for identifiable frequencies F _{fact. rvd} ; F _{fact. sep.} ; the vibration sensor is built into an electronic device located on the engine casing, the output of the vibration sensor is connected to the VSV spectrum calculator, the identification unit for the frequency of rotation of the IAS of the rotor of the _{high pressure hitch} in the spectrum of the measured vibration process with the calculated value of the frequencies F _{rhh. calc.} ± Δf and comparing the vibration velocity with the calculated value of V _{rvd. fact.} ≥V _{rvd. calculation} connected to the second output when the vibration velocity is exceeded V _{rvd. calc.} to the first normally open switch (P1) connecting the output of the BCB unit to the input of the identification unit of the rotational speed of the separator of the rotor bearing in the spectrum of the measured vibration process with the calculated frequency value F _{sept. calc.} ± Δf and comparing the vibration velocity with the calculated value of V _{sept. fact.} ≥V _{rvd. calc.} , the second output of which is in excess of the calculated vibration velocity V _{rvd. calc.} connected to the second normally open switch (P2) connecting the output of the BCB with the input of the identification block of the rotor speed identification of the RND in the spectrum of the measured vibration process with the calculated identified frequency value F _{rnd. calc.} ± Δf and comparing the vibration velocity with the calculated value of V _{rnd. fact.} ≥V rnd _{. calc.} , the output of the IAN block of the RND rotor by exceeding the vibration velocity - V _{rnd. calc.} It is connected to the third normally open switch (P3) connecting the IHV block of the inter-rotor bearing separator with a third output according to the actual vibration speed of the separator and the input of the unit for comparing the actual vibration speed of the separator with the boundary level of the separator vibration _speed , V _f.sep. ≥V _Sep. the output of which is connected to the fourth normally open switch (P4) connecting the on-board power supply to the indicator: “dangerous vibrations of the inter-rotor bearing (OV MRP)”, and the electronic device is connected to the on-board power supply through the push-button push-button “Control” in the cockpit preset speed of the WFD.