Author: Leister, Tim
Publisher: KIT Scientific Publishing
ISBN: 3731511126
Category : Technology & Engineering
Languages : en
Pages : 192
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Book Description
The gas foil bearing (GFB) technology is a key factor for the transition to oil-free rotating machinery. Among numerous advantages, GFBs offer the unique ability to be lubricated with working fluids such as refrigerants. However, the computational analysis of refrigerant-lubricated GFB–rotor systems represents an interdisciplinary problem of enormous complexity. This work pushes forward existing limits of feasibility and establishes a new strategy that enables stability and bifurcation analyses.
Author: Mathieu Garcia
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Internal experiments at Liebherr-Aerospace FRANCE on new refrigerant-lubricated compressor designs have shown that under specific operating conditions, a mixture of vapor and liquid appears in the compressor, instead of a single-phase vapor flow. Therefore, refrigerant-lubricated foil bearings behavior is studied, including the likelihood of two-phase flow in the lubricant. We focus on the lubricant behavior only, in the operating conditions of foil bearings. The Thermo-Hydrodynamic approach describes lubricant characteristics such as pressure, density, viscosity, and temperature. It involves the use of a generalized Reynolds equation for turbulent flow, a nonlinear cubic equation of state for two-phase flow and a 3D turbulent thin-film energy equation. Journal bearing global parameters are calculated for steady-state conditions.
Author: Athanasios Chasalevris
Publisher: Springer Nature
ISBN: 3031323947
Category : Technology & Engineering
Languages : en
Pages : 218
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Book Description
This book reports on cutting-edge experimental and numerical findings related to the application of active bearings, including smart ones, in rotating machinery. It discusses their role in improving stability and control of rotor systems and reports in depth on the corresponding modeling and control approaches. Chapters are based on peer-reviewed contributions to the 1st Workshop on Active Bearings in Rotating Machinery (ABROM 2022), held on June 29- 30, 2022, in Athens, Greece, and organized in collaboration between the School of Mechanical Engineering of The National Technical University of Athens (NTUA) and the Faculty of Mechanical Engineering of Karlsruhe Institute of Technology (KIT). In connection with the increasing digital transformation of machine elements, this book offers a timely perspective and extensive information on testing methods and experimental procedures involved in the development of intelligent rotors for industrial applications.
Author: Aramendiz Fuentes, Jimmy Alberto
Publisher: KIT Scientific Publishing
ISBN: 373151267X
Category :
Languages : en
Pages : 180
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Book Description
This work considers dampers that do not solely focus on a single strategy but instead combine them. The capabilities of conventional dry friction dampers are expanded by taking into account piecewise defined contact geometries. This leads to friction dampers that change their behavior depending on the amplitude of the oscillations. The vibration damping device in this work, introduces damping at high oscillation amplitudes and takes advantage of absorption at low oscillation amplitudes.
Author: A. Tondl
Publisher:
ISBN:
Category :
Languages : en
Pages : 17
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Book Description
The report explores self-excited vibration induced in rotors of gas lubricated bearings.
Author: Krzysztof Czolczynski
Publisher: Springer
ISBN: 9781461271765
Category : Technology & Engineering
Languages : en
Pages : 152
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Book Description
A discussion of models for the behaviour of gas bearings, particularly of the aspects affecting the stability of the system. The text begins with a discussion of the mathematical models, identifying the stiffness and damping coefficients, and describing the behaviour of the models in unstable regions. It then turns to apply these results to bearings: static characteristics and stability of various rotor systems and an extensive discussion of air rings.
Author: Zolton N. Nemeth
Publisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 36
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Book Description
Author: Zolton N. Nemeth
Publisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 52
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Book Description
Author: Ampex Corporation. Advanced Technology Division
Publisher:
ISBN:
Category : Fluid-film bearings
Languages : en
Pages : 16
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Book Description
Author: L. Licht
Publisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 180
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Book Description
Flexible-surface thrust and journal foil-bearings of novel design were fabricated, and their performance was convincingly demonstrated, both individually and jointly as a unified rotor-support system. A versatile rig was constructed and instrumented, and experimental results are copiously documented with graphs and oscilloscopic data of trajectories, waveforms, and scans of amplitude response. The thrust bearings combine advantages of surface compliance with the superior load capacity of the spiral-groove configuration. The flexible supports provide means of deliberate control of clearance topography, in contrast to bearings in which the formation of the lubricating wedge is casual and incidental. At speeds of 40,000 to 45,000 rpm and a mean clearance of the order of 15 to 20 micrometers (600 to 800 micro in.), the resilient, air-lubricated, spiral-groove thrust bearings comfortably support a load of 127 N (29 lb; 13 kgf), equivalent to 3.0 N/sq. cm. (4.5 lb/sq in, 0.31 kgf/sq cm). The construction of journal foil-bearings is extremely simple. In one design, a coiled ribbon of plane foil and a retaining cartridge constitute the only components. In another design, the plane foil is integral with a section preformed to an open octagon with rounded vertices. A radical departure from operational characteristics of rigid gas bearings is achieved.
