Experimental research of rotor axis revolution orbit in rotor systems with adaptive and sleeve sliding-friction bearings

Transcription

1 38 ISSN MECHANIKA. 8. Nr. (7) Experimental research of rotor axis revolution orbit in rotor systems with aaptive an sleeve sliing-friction s V. Vekteris*, A. Čereška**, M. Jurevičius***, V. Striška**** *Vilnius Geiminas Technical University, J. Basanavičiaus 8, 3 Vilnius, Lithuania, vekteris@me.vgtu.lt **Vilnius Geiminas Technical University, J. Basanavičiaus 8, 3 Vilnius, Lithuania, aurius@me.vgtu.lt ***Vilnius Geiminas Technical University, J. Basanavičiaus 8, 3 Vilnius, Lithuania, minaju@me.vgtu.lt ****Vilnius Geiminas Technical University, J. Basanavičiaus 8, 3 Vilnius, Lithuania, vytautas@me.vgtu.lt 1. Introuction Most researchers [1, ] of rotating systems appls orbits of rotor for Tilting Pa Journal Bearings to estimate their operation quality. The orbits of vibrations show vibration biases of rotor bolsters, relative an absolute phases relative frequency, that is amplitue of the change of biases of relative vibrations of the rotor in raial irection an the frequency with respect to the frequency of rotor rotation an the frequency of raial vertical vibrations with respect to the frequency of raial horizontal vibrations, trajectory of vibrations, trajectory of precession of the rotor with respect to its trajectory of rotation, configuration of eflection of a roller [3]. Bias of configuration of the orbit escribes the change of ynamical workloas on the rotor, what inicates perfection of the construction, accuracy of its mounting. Practice has shown [9, 1] that graphs of orbits are informative especially for quality research of the s operating at high spees. Working quality of a researching graphs of rotor orbits at ifferent frequencies of rotation is analyze in this work.. Testing systems Relative boy wise isplacements of the rotor 1 (Fig. 1) are measure by noncontact inuction isplacement transucers 3. The irection of rotation an angular velocity of the rotor are measure from the mark by photoelectric phase transucers 5. The phase converter synchronizes signals of the isplacement converters 3. Absolute vibrations of the rotor s boy are measure by accelerometers which signals amplifie by the primary amplifiers 8 are sent to the measurement signal input/output boar 1 of the computer 9. Signals of inuction isplacement transucers 3 an the phase converter 5 are also sent to the boar. The computer 9 processes the signals registere with the versatile boar 1 by using Origin, Data Master an Statistika, Excel or other software packages. Noncontact inuction isplacement transucers have been selecte to etermine eviation (beating) of the rotary motion of the rotor. Two transucers mounte at 9 angle are use to etermine the rotary trajectory (orbit) of the rotor s pivot. The functional iagram is presente in Fig. 1. version I version II version III Fig. 1 Testing system of a rotor system with aaptive viscous-friction s: 1 - rotor; - spinle hea, 3 - noncontact inuction isplacement transucers, - accelerometers, 5 - photoelectric phase transucers, - mark, 7 - amplifier, 8 - primary amplifiers, 9 - computer, 1 - measurement signal input/output boar, 11 - printer

2 39 3. Diagnostic measurements Diagnostic measurements of aaptive (version I an sleeve (version III) sliing-friction s are performe as follows: after mounting the s of aequate structure on the spinle hea an connecting the rive motor, the converters are mounte, amplification of measuring channels is ajuste an calibration is performe. The rotor s river is switche on an the esire angular velocity of the rotor is set. The angular velocity regulation range is as follows: rev/min. When the rotor reaches a stable preset rotary velocity the Experiment application is run in the computer. Measurement signals from both isplacement transucers, accelerometers an the strobe converter are registere within 1-15 interval limits. to 75 Hz Ban Pass Filter on EMA8_C 1 8 Y Axis Title ,,,,,8 1, 1, X Axis Title to 75 Hz Ban Pass Filter on EMA8_D 8 Y Axis Title - -,,,,,8 1, 1, X Axis Title Fig. Results of measurements The ata is recore into the create ata file an information files. A text file with a specifie file name is create from these files. Further it is processe by means of Origin, Statistika or other software packages in accorance with respective methos (Fig. ). By varying angular velocity of the rotor it is possible to take reaings an to analyze the interrelation of the rotor orbits at ifferent angular rotary velocities, types of aaptive an sleeve sliing-friction s, an absolute vibrations of the spinle hea boy in ifferent irections an at ifferent locations.. Analysis of results From the analysis of the rotor axis revolving orbits, measure an calculate accoring the signals of vibro-isplacement transucers an the signals of accelerometers at ifferent rotation frequencies when the rotor revolves in two aaptive an sleeve sliing-friction s (see Fig. 3), it is possible to notice the following regularities. At the increase of revolution frequency (155; 51; 553; 39 rev/min to see Table) forms of the orbits stabilize an become more constant. At the revolution frequency 35 an 77 rev/min the form of orbits is the most stable. At further increase of the frequency (59; 51 rev/min to see Table) they again become less stable because of temperature influence on the lubricant. At further increase of revolution frequency it woul be necessary to increase synchronously the clearance in the.

3 Type of Accoring to signals of vibration isplacement transucers The summary table of experimental ata Accoring to signals of accelerometers Rotating spee 7 rev/min The orbits of the rotor axis Accoring to signals of vibration isplacement transucers Table Accoring to signals of accelerometers Sleeve sliingfriction Rotating spee 155 rev/min Rotating spee 51 rev/min Rotating spee 553 rev/min Rotating spee 39 rev/min Aaptive sliingfriction Rotating spee 35 rev/min Rotating spee 77 rev/min Rotating spee 59 rev/min Rotating spee 51 rev/min Difference of orbit forms, receive by measurement using vibro-isplacement transucers an accelerometers with ouble integration of later signals an filtration by special methoics prepare by the authors, coul be explaine ue to not enough quality of signal filtration an not compatible signal scale of vibro-acceleration an integrate vibro-isplacement. At a set of constant coefficients an correction of calibration methoics this noncompatibility can be ecrease. Revolution orbits of the rotor in a bush type sliing were measure only at revolution frequency 7 rev/min. They are more stable, but ifference between them is higher an further research is necessary to explain the reasons. Fig. shows the orbits receive by measurement with vibro-isplacement transucers an accelerometers after ouble integration an filtration of the signals later, when the revolution frequency was 35 rev/min. At measurement by accelerometer the signals are not ecoe in full. The orbits are not fully informative an to conclue the reliability of iagnostics from them aitional research is neee. At further improvement of the methoics of measurement an analysis it woul be necessary to receive

4 1 the measurement signals together with the revolution frequency transucer (stroboscope) signals an to search for connection between these signals that is to efine non coincience of the phases an relation between the phases receive by measurement with ifferent transucers. 5. Error analysis Rotary system with hyroynamic s is not strong straight but it coul be linearise. In this case it is necessary to fin such value of operator, that the function of error woul be close to zero [3]. () t = Y () t AX () t Δ (1) here X () t is revolution fluctuations of the rotor (Input signal); Y () t is frame fluctuations of the rotor (Output signal); A is operator; Δ () t is function of error. Operator 1 A = A( σ x ) = K yx ( ). () σ x Results of errors counts are given in the graphs (Fig. 3, a an b). The results - graphs of counts of measurement transucers that are fixe horizontally: error Δ ( t) (Fig. 3, a). The results - graphs of counts of measurement transucers that are fixe vertically: error Δ () t (Fig. 3, b). Amplitue, μm Amolitue, μm ,,5,3,35,,5,5 a Time, s,,1,,3,,5 Time, s b Δ ; a - horizontal converter, b - vertical converters Fig. 3 Rotor rotation frequency 5 rev/min, error ( t). Conclusions 1. Dynamic error Δ () t (Fig. 3, a an b) shows that practice of accelerometers is possible an expeient being confusing constructions of rotors systems.. Dynamic stanar eviation of error Δ (t) between oscillations is.151 μm (Fig. 3, a) an.353 μm (Fig. 3, b). Right measurement results are got at measurement by noncontact inuction isplacement converters. 3. It is necessary to o researches improving measurement methoology of rotor revolution orbits using accelerometers. References 1. Bently, D.E., Hatch, CH. T. Funamentals of Rotating Machinery Diagnostics. -Bently Pressurize Bearing Company, printe in Canaa, first printing,.-7p.. Muszynska, A. (Agnes) Rotorynamics.-CRC Press, Taylor&Francis, 5. -New York, Printe in USA. -118p. 3. Vekteris, V., Jurevičius, M. Rotor vibrations within tilting-pa journal s. -The Inian Institute of Technology, The Cooperative Research Centre on Integrate Engineering Asset Management, Australia.-New Delhi: IIT Kanpur & CIEAM,, v.ii, p Vekteris, V., Čereška A. Diagnostic errors of rotating systems with sliing. -Scientific Symposium: Metrology an Metrology Assurance.-Sozopol, Bulgaria,. p Čereška, A., Vekteris, V. Analytical research of hyroinamic s in mechatronical systems.-soli State Phenomena.-Trans tech publications LTD, 5, v.113, p Vekteris, V., Čereška, A., Jurevičius, M. Diagnostics of functioning of the hyroynamic tilting-pa journal.-tmt Antalia, Turkey: Faculty of Mechanical Engineering in Zenica, 5, p Vekteris, V. Autoaaptive flui film s.-mechanika.-kaunas: Technologija,, Nr.(), p Vekteris, V., Čereška, A. Diagnostics of functioning quality of the systems with sliing s. -Mechanika. -Kaunas: Technologija,, Nr.(3), p Vekteris, V., Čereška, A. Statistical methos in iagnostic of rotor system. -Proceeings / University of Sarajevo, Faculty of Mechanical Engineering in Zenica (Bosnia an Herzegovina), Universitetat Politécnica e Catalunya, Escola Tècnica Superior D'enginyeria Inustrial e Barcelona, Department D'enginyeria Mecànica (Spain).-Zenica: Faculty of Mechanical Engineering,, p Vekteris, V., Čereška, A. Mechatronical systems of tilting-pa journal testing.-international Scientific Conference on the Occasion on the 55th Anniversary of Founing the Faculty of Mechanical Engineering of the VSB Technical Universary of Ostrava. Proceeing Czech Republic.-Ostrava, 5, p.3.

5 V. Vekteris, A. Čereška, M. Jurevičius, V. Striška ROTORINIŲ SISTEMŲ SU ADAPTYVIAISIAIS IR ĮVORINIAIS SLYDIMO TRINTIES GUOLIAIS ROTORIŲ AŠIŲ SUKIMOSI ORBITŲ EKSPERIMENTINIAI TYRIMAI R e z i u m ė Straipsnyje nagrinėjamas rotorinių sistemų su aaptyviais ir įvoriniais slyimo guoliais rotorių ašių sukimosi orbitų tikslumas, matuojant vibracinius poslinkius bekontakčiais poslinkių keitikliais (tiesioginis matavimo būas) ir vibracinius pagreičius akcelerometrais (netiesioginis matavimo būas). Atlikti rotorinių sistemų eksperimentiniai ir teoriniai tyrimai. Iš gautų matavimo rezultatų suarytos rotorių ašių sukimosi orbitos bei kiti analizei reikalingi uomenų formatai. Nustatytos rotorių ašių sukimosi orbitų netaisyklingos formos susiarymą įtakojančios priežastys bei priklausomybės tarp aaptyvių ir įvorinių slyimo guolių tyrimo rezultatų, bei rezultatų, gautų matuojant tiriamąją sistemą tiesioginiu ir netiesioginiu matavimo būais. Atlikta gautų rezultatų analizė ir pateiktos išvaos, apie rotorinių sistemų rotorių ašių sukimosi tikslumo iagnostinių tyrimų rezultatus. V. Vekteris, A. Čereška, M. Jurevičius, V. Striška EXPERIMENTAL RESEARCH OF ROTOR AXIS REVOLUTION ORBIT IN ROTOR SYSTEMS WITH ADAPTIVE AND SLEEVE SLIDING-FRICTION BEARINGS S u m m a r y The accuracy of revolving orbits of rotor axes in rotor systems with aaptive an sleeve sliing-friction s is analyze in the paper measuring vibration isplacements by contact less isplacement transucers (straight measurement metho) an vibration accelerometers (nonstraight measurement metho). Experimental an theoretical research of rotor systems was performe. On the basis of receive measurement results rotational orbits of rotor axes an other ata formats necessary for analysis were forme. Reasons influencing the formation of irregular form of rotor axes revolving orbits an epenencies between the research results of aaptive an sleeve sliingfriction s an the results receive by measurement of the searche system by straight an nonstraight methos were efine. Analysis of the receive results is mae an conclusions are presente about the iagnostic of revolution accuracy of rotor axes in rotor systems. В. Вектерис, А. Черешка, М. Юревичюс, В. Стришка ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ОРБИТ ВРАЩЕНИЯ ОСЕЙ РОТОРОВ В РОТОРНЫХ СИСТЕМАХ С АДАПТИВНЫМИ И ВТУЛОЧНЫМИ ПОДШИПНИКАМИ ЖИДКОСТНОГО ТРЕНИЯ Р е з ю м е В настоящей работе приведены результаты исследования точности орбит вращения осей роторных систем с адаптивными и втулочными подшипниками скольжения, измеряя перемещения бесконтактными датчиками (метод прямого измерения) и виброускорение акцелерометрами (метод косвенного измерения). Проведены экспериментальные и теоретические исследования роторных систем. Из полученных результатов измерений сформулированы орбиты вращения осей ротора и другие форматы данных необходимые для дальнейшего анализа. Установлены причинны влияющие на форму орбит, установлена взаимосвязь между характеристиками адаптивных и втулочных подшипников скольжения, а также между результатами, полученными измеряя прямым и косвенным методами. Проведен анализ полученных результатов диагностических исследований точности вращения оси ротора и сформулированы выводы. Receive January 8, 8