Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings
New closed-form expressions for calculating the linear stability thresholds for rigid and flexible Jeffcott systems and the imbalance response for a rotor supported on a hybrid bearing are presented. For typical bearings characteristics, expressions yield stability thresholds practically equal to th...
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| Format: | Article |
| Language: | English |
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Wiley
2005-01-01
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| Series: | International Journal of Rotating Machinery |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1155/IJRM.2005.16 |
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| _version_ | 1832562397563322368 |
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| author | Julio Gomez-Mancilla Valeri Nosov Gerardo Silva-Navarro |
| author_facet | Julio Gomez-Mancilla Valeri Nosov Gerardo Silva-Navarro |
| author_sort | Julio Gomez-Mancilla |
| collection | DOAJ |
| description | New closed-form expressions for calculating the linear
stability thresholds for rigid and flexible Jeffcott systems and
the imbalance response for a rotor supported on a hybrid bearing
are presented. For typical bearings characteristics, expressions yield stability thresholds practically equal to those reported by
Lund (1966). The hybrid bearing design has a single injection
port whose location is so chosen to stabilize the bearing
performance and to reduce the steady equilibrium attitude angle.
Rotordynamics coefficients graphs for conventional and
pressurized bearings, as functions of bearing equilibrium
eccentricity and/or Sommerfeld number, are presented. Using the
rotordynamics coefficients into the expressions for the
corresponding velocity thresholds and the imbalance response, the
system stability and vibration performances are estimated and
analyzed. When comparing the Jeffcott flexible shaft supported on
two journal bearings of the conventional type with the hybrid
type, the results show a clear superiority of the pressurized
design as far as stability behavior is concerned. Specifically
for cases of flexible shafts with similar characteristics to
those used in industry, the analysis shows that this design yields
velocity thresholds 25%–40% higher compared to the
conventional circular ones. Also this bearing displays nonlinear
feeding pressure behavior, and it is capable of reducing the
synchronous vibration amplitude in most speed ranges, except
around the critical speed; moreover, for certain Jeffcott
configurations the amplitude reduction can be substantial. |
| format | Article |
| id | doaj-art-4b2839da6d0048299de4459a8d5f200f |
| institution | Kabale University |
| issn | 1023-621X 1542-3034 |
| language | English |
| publishDate | 2005-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Rotating Machinery |
| spelling | doaj-art-4b2839da6d0048299de4459a8d5f200f2025-02-03T01:22:44ZengWileyInternational Journal of Rotating Machinery1023-621X1542-30342005-01-0120051162210.1155/IJRM.2005.16Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional BearingsJulio Gomez-Mancilla0Valeri Nosov1Gerardo Silva-Navarro2Laboratorio de Vibraciones & Rotodinamica ESIME, Instituto Politecnio Nacional, Edificio 5, 3er Piso, Colonia Zacatenco, Distrito Federal, Mexico 07300, MexicoLaboratorio de Vibraciones & Rotodinamica ESIME, Instituto Politecnio Nacional, Edificio 5, 3er Piso, Colonia Zacatenco, Distrito Federal, Mexico 07300, MexicoSeccion de Mecatronica, Centro de Investigacion y de Estudios Avanzados del IPN, A.P. 14-740, Distrito Federal, Mexico 07360, MexicoNew closed-form expressions for calculating the linear stability thresholds for rigid and flexible Jeffcott systems and the imbalance response for a rotor supported on a hybrid bearing are presented. For typical bearings characteristics, expressions yield stability thresholds practically equal to those reported by Lund (1966). The hybrid bearing design has a single injection port whose location is so chosen to stabilize the bearing performance and to reduce the steady equilibrium attitude angle. Rotordynamics coefficients graphs for conventional and pressurized bearings, as functions of bearing equilibrium eccentricity and/or Sommerfeld number, are presented. Using the rotordynamics coefficients into the expressions for the corresponding velocity thresholds and the imbalance response, the system stability and vibration performances are estimated and analyzed. When comparing the Jeffcott flexible shaft supported on two journal bearings of the conventional type with the hybrid type, the results show a clear superiority of the pressurized design as far as stability behavior is concerned. Specifically for cases of flexible shafts with similar characteristics to those used in industry, the analysis shows that this design yields velocity thresholds 25%–40% higher compared to the conventional circular ones. Also this bearing displays nonlinear feeding pressure behavior, and it is capable of reducing the synchronous vibration amplitude in most speed ranges, except around the critical speed; moreover, for certain Jeffcott configurations the amplitude reduction can be substantial.http://dx.doi.org/10.1155/IJRM.2005.16Jeffcott rotorhybrid bearingimbalance response pressurized rotordynamics coefficientsstability threshold. |
| spellingShingle | Julio Gomez-Mancilla Valeri Nosov Gerardo Silva-Navarro Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings International Journal of Rotating Machinery Jeffcott rotor hybrid bearing imbalance response pressurized rotordynamics coefficients stability threshold. |
| title | Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings |
| title_full | Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings |
| title_fullStr | Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings |
| title_full_unstemmed | Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings |
| title_short | Rotor-Bearing System Stability Performance Comparing Hybrid versus Conventional Bearings |
| title_sort | rotor bearing system stability performance comparing hybrid versus conventional bearings |
| topic | Jeffcott rotor hybrid bearing imbalance response pressurized rotordynamics coefficients stability threshold. |
| url | http://dx.doi.org/10.1155/IJRM.2005.16 |
| work_keys_str_mv | AT juliogomezmancilla rotorbearingsystemstabilityperformancecomparinghybridversusconventionalbearings AT valerinosov rotorbearingsystemstabilityperformancecomparinghybridversusconventionalbearings AT gerardosilvanavarro rotorbearingsystemstabilityperformancecomparinghybridversusconventionalbearings |