Showing papers on "Fluid bearing published in 1975"
107 citations
35 citations
DOI•
01 Oct 1975TL;DR: In this article, the steady-state transient response of the squeeze film damper bearing was investigated, and the steady state and transient equations for the hydrodynamic bearing forces were derived; these coefficients were used to find the damper configuration which will provide the optimum support characteristics based on a stability analysis of the rotor bearing system.
Abstract: The steady-state transient response of the squeeze film damper bearing was investigated. Both the steady-state and transient equations for the hydrodynamic bearing forces are derived; the steady-state equations were used to determine the damper equivalent stiffness and damping coefficients. These coefficients are used to find the damper configuration which will provide the optimum support characteristics based on a stability analysis of the rotor-bearing system. The effects of end seals and cavitated fluid film are included. The transient analysis of rotor-bearing systems was conducted by coupling the damping and rotor equations and integrating forward in time. The effects of unbalance, cavitation, and retainer springs are included. Methods of determining the stability of a rotor-bearing system under the influence of aerodynamic forces and internal shaft friction are discussed.
30 citations
01 May 1975
TL;DR: In this paper, a study of the steady-state and transient response of the squeeze film damper bearing is presented, where the bearing equivalent stiffness and damping coefficients are determined by steady state equations.
Abstract: A study of the steady-state and transient response of the squeeze film damper bearing is presented. Both the steady-state and transient equations for the hydrodynamic bearing forces are derived. The bearing equivalent stiffness and damping coefficients are determined by steady-state equations. These coefficients are used to find the bearing configuration which will provide the optimum support characteristics based on a stability analysis of the rotor-bearing system. The transient analysis of rotor-bearing systems is performed by coupling the bearing and journal equations and integrating forward in time. The effects of unbalance, cavitation, and retainer springs are included in the analysis. Methods of determining the stability of a rotor-bearing system under the influence of aerodynamic forces and internal shaft friction are discussed with emphasis on solving the system characteristic frequency equation and on producing stability maps. It is shown that for optimum stability and low force transmissability the squeeze bearing should operate at an eccentricity ratio epsilon 0.4.
18 citations
17 citations
Patent•
24 Apr 1975
TL;DR: A bearing assembly for the rotors of a rotary screw variable volume gas machine, as a compressor expander or fluid pump, includes opposed thrust and high radial load bearings at the high pressure end of each rotor and high thrust bearings for each rotor shaft at the low pressure end as discussed by the authors.
Abstract: A bearing assembly for the rotors of a rotary screw variable volume gas machine, as a compressor expander or fluid pump, includes opposed thrust and high radial load bearings at the high pressure end of each rotor and high thrust bearings for each rotor shaft at the low pressure end. An axial force is applied to each of the bearings at the low pressure end, opposing the axial load on the screws from the working fluid, tending to equalize the thrust load on the bearings at the high pressure end so that bearing wear is relatively even and bearing life is improved.
17 citations
17 citations
13 citations
10 citations
9 citations
TL;DR: In this paper, a small rotor with oilless (air-lubricated) foil bearings was used for high-speed turbomachines at speeds up to and in excess of 3,500 rps (210,000 rpm).
Abstract: Experiments are conducted with 3 types of oilless (air lubricated) foil bearings and a small rotor, at speeds up to and in excess of 3,500 rps (210,000 rpm). The modular construction of the experimental apparatus provides for interchangeability of foil retainers in the supporting brackets, for their alignment, and for the positioning of bearings at various stations along the rotor axis. The symmetrical rotor, 12.7 cm (5.0 in.) long and weighing 2.97 N (0.667 lb) has both cylindrical and conical journals. The main purpose of the investigation is a preliminary examination of whirl-suppressing (stabilizing) characteristics of these flexible bearings, with the objective of application to small high-speed turbomachines.
01 Feb 1975
TL;DR: In this paper, the authors present a review of the state-of-the-art for the design of self-acting gas-lubricated bearing systems and their performance.
Abstract: 1 Schuller, F. T., \"Experiments on the Stability of Various WaterLubricated Fixed Geometry Hydrodynamic Journal Bearings at Zero Load,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 98, No. 4, Oct. 1973, pp. 434-446. 2 Cunningham, R. E., Fleming, D. P., and Anderson, W. J., \"Experimental Stability Studies of the Herringbone-Grooved Gas-Lubricated Journal Bearings,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS; ASME, Series F, Vol. 91, No. 1, Jan. 1969, pp. 52-59. 3 Fuller, D. D., \"A Review of the State-of-the-Art for the Design of Self-Acting Gas-Lubricated Bearings,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 91, No. 1, Jan. 1969, pp. 1-16. 4 Lund, J. W., and Orcutt, F. K., \"Calculations and Experiments on the Unbalance Response of a Flexible Rotor,\" Journal of Engineering for Industry, TRANS. ASME, Series B, Vol. 88, No. 4, Nov. 1967, pp. 785-796. 5 Mech., C , \"Application of Gas Bearings to Turbomachines,\" Paper No. 4, Proceedings of the 4-th Gas Bearing Symposium, University of Southampton (England), Apr. 1969. 6 Castelli, V., and McCabe, J. T., \"Transient Dynamics of a TiltingPad Gas Bearing System,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 89, No. 3, Oct. 1967, pp. 499-509. 7 Chu, T. Y., McCabe, J. T„ and Elrod, H. G., \"Stability Considerations for Gas-Lubricated Tilting-Pad Journal Bearings,\" Part 1 and Part 2, JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 90, No. 1, Jan. 1968, pp. 162-172, and Series F, Vol. 94, No. 3, July 1972, pp. 223-233. 8 Tondl, A., \"Experimental Investigation of Self-Excited Vibrations of Rotors due to the Action of Lubricating Oil Film in Journal Bearings,\" Monograph and Memoranda Series, No. 1, National (Checkoslovak) Research Institute for Machine Design, Prague, 1961. 9 Stodola, A., Steam and Gas Turbines, McGraw-Hill, New York, 1927. 10 Tanaka, M., and Hori, Y., \"Stability Characteristics of Floating Bush Bearings,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 94, No. 2, July 1972, pp. 248-259. 11 Lund, J. W., \"Rotor-Bearing Dynamics Design Technology, Part VII: The Three Lobe Bearing and Floating Ring Bearing,\" Technical Report AFAPL-TR-65-45, Part VII, Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohio, Feb. 1968. 12 Vohr, J., and Chow, C , \"Rotor-Bearings Dynamics Design Technology. Part VIII: Spiral Grooved Floating Ring Journal Bearing,\" Technical Report AFAPL-TR-65-45, Part Vm, Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohio, Apr. 1969. 13 Lund, J. W., \"The Stability of an Elastic Rotor in Journal Bearings With Flexible, Damped Supports,\" Journal of Applied Mechanics, Vol. 22, TRANS. ASME, Vol. 87, Series E, No. 4, Dec. 1965, pp. 911-920. 14 Marsh, H., \"The Stability of Self-Acting Gas Journal Bearings with Noncircular Members and Additional Elements of Flexibility,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 91, No. 1, Jan. 1969, pp. 113-119. 15 Powell, J. W., and Tempest, M. C„ \"A Study of High Speed Machines with Rubber Stabilized Air Bearings,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 90, No. 4, Oct. 1968, pp. 701-708. 16 Barnett, M. A., and Silver, A., \"Applications of Air Bearings to High-Speed Turbomachinery,\" SAE Paper No. 700720, Combined National Farm, Construction & Industrial Machinery and Powerplant Meeting, Wisconsin, Sept. 1970. 17 Heuer, D. F., and Collins, R. A., \"Dynamic and Environmental Evaluation of Compliant Foil Gas Lubricated Bearings,\" Technical Report AFAPL-TR-73-56, Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohio, June 1973. 18 Licht, L., \"An Experimental Study of High-Speed Rotors Supported by Air-Lubricated Foil Bearings. Part 1: Rotation in Pressurized and Self-Acting Foil Bearings, and Part 2: Response to Impact and to Periodic Excitation,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 91, No. 3, July 1969, pp. 447-505. 19 Licht, L., \"The Dynamic Characteristics of a Turborotor Simulator Supported on Gas-Lubricated Foil Bearings. Part 1: Response to Rotating Imbalance and Unidirectional Excitation, Part 2: Operation with Heating and Thermal Gradients, and Part 3: Rotation with Foil Bearings of Reduced Length with Starting and Stopping Unaided by External Pressurization,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 92, No. 4, Oct. 1970, pp. 630-660, and Vol. 94, No. 3, July 1972, pp. 211-222. 20 Eshel, A., \"Dynamic Analysis of Three-Foil Rotor Support System in Zero-Gravity Environment,\" JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 92, No. 4, Oct. 1970, pp. 617629. 21 Licht, L, Branger, M. and Anderson, W. J., \"Gas-Lubricated Foil Bearings for High-Speed Turbo-Alternator. Construction and Performance,\" Paper No. 73-Lub-5, ASME-ASLE Joint Lubrication Conference, Atlanta, Georgia, Oct. 1973. JOURNAL OF LUBRICATION TECHNOLOGY, TRANS. ASME, Series F, Vol. 96, No. 2, Apr. 1974, pp. 215-223. 22 Licht, L., and Branger, M., \"Design, Fabrication and Performance of Foil Journal Bearings for the Brayton Rotating Unit (BRU),\" NASA Report No. CR-2243, Contract No. NAS3-15341, NASA Lewis Research Center, Cleveland, Ohio, July 1973. 23 Davis, J. E., Gildersleeve, R. B., and Pietsch, A., \"The Design and Fabrication of the Brayton Rotating Unit (BRU),\" AiResearch Manufacturing Company of Arizona, Final Report No. APS-5334-R, Contract No. NAS3-9427, NASA Lewis Research Center, Cleveland, Ohio, May 1971.
TL;DR: In this article, the linearity of the stage motion was such that the coefficient of the quadratic term was less than 10-7 mm-1, and various characteristics of air bearings were obtained as functions of the inlet diameter, inlet depth, air pressure, air flow, load, and lift height.
Abstract: Air bearings with a 2 mm inlet hole were used as the linear bearings for the moving stages of a precision coordinate measuring device. The linearity of the stage motion was such that the coefficient of the quadratic term was less than 10-7 mm-1. Various characteristics of air bearings were obtained as functions of the inlet diameter, inlet depth, air pressure, air flow, load, and lift height. A fluid dynamical analysis of these characteristics using simplifying assumptions gave results which agreed with measurements within factors of 2 to 3.