Showing papers on "Fluid bearing published in 1973"

Hydrodynamic Lubrication of a Porous Slider

Abstract: A plane porous slider bearing is analysed and closed form expressions for pressure, load, frictional drag, coefficient of friction and centre of pressure are obtained. The effect of porosity is to decrease the load capacity and friction. However, the coefficient of friction is increased.

Vortex diffuser fluid bearing device

Abstract: A fluid bearing load supporting system having unidirectional and omnidirectional capabilities which embodies means for forming one or a plurality of fluid vortices for separating a body from a supporting surface by an intervening cushion of fluid, providing therewith an extremely low coefficient of friction that facilitates a conveyance of the body for the purposes of transportation, processing, treatment and the like.

A Hydrodynamic Theory of Radial-Face Mechanical Seals

Abstract: The existence of a lubricating fluid film between the faces of a mechanical seal has been amply demonstrated, but the mechanisms of lubrication and sealing have yet to be convincingly established. Experimental evidence to show that mechanical seal faces are most probably lubricated by a hydrodynamic action induced by the waviness of one of the surfaces has recently been published by the authors. Following this work a modified form of the narrow bearing approximation to Reynolds' equation for hydrodynamic lubrication has been applied to an idealized wavy faced seal. The resulting theory of seal face lubrication has been extended to include radial flows in the fluid film and predicts a net inward flow of fluid which may be utilized to oppose the flow due to the sealed fluid pressure. Predicted lubrication and sealing characteristics are in substantial agreement with measured values. It is suggested that the performance of mechanical seals can be improved by giving one face an appropriately wavy surface at t...

A Numerical Solution for the Hydrodynamic Lubrication of Finite Porous Journal Bearings

Abstract: We present a numerical solution for the operating conditions of a hydrodynamic porous journal bearing. The numerical method allows for the possibility of variable porosity in the bearing matrix, bu...

Fluid bearing support for tiltable metallurgical vessels

Abstract: Concept and application of balanced fluid load support of tiltable, heavy loads, for example metallurgical vessels such as a basic oxygen furnace. Fluid bearing structures are provided which compensate for sag along the axis of BOF trunnion shafts due to the weight of the vessel and its load and also compensate for effects of sag during repeatedly changing load and tilting conditions. Such fluid bearing structures also provide for expansion along the axis of the trunnion shafts due to changing temperature conditions encountered by the vessel and its support structure, provide for long-life ease of rotation of the vessel about the trunnion shaft axis, and further provide indications of bearing operating conditions.

Experimental Investigation of Air Bearings for Gas Turbine Engines

Abstract: An experimental gas-bearing test program was initiated to establish the answer to two specific questions. Is present-day gas bearing technology accurate enough to predict actual bearing performance under typical jet engine operating conditions? And, are gas journal and thrust bearings capable of carrying the required high operating loads that can be imposed by the engine when maneuvering at high. altitudes, which are considered the most severe bearing operating conditions? A bearing element component rest rig was built to simulate jet engine conditions. Tests were performed and the results, reported herein, indicate positive answers lo the above questions. Presented at the 28th ASLE Annual Meeting in Chicago, Illinois, April 30–May 3, 1973

Thrust bearing assembly

Abstract: A thrust bearing assembly having a first spirally grooved bearing face engaging a second ungrooved face. Lubricant is delivered under pressure to an annular groove circumscribing the spiral grooves. A portion of the lubricant is drawn into the spiral grooves to provide a hybrid hydrostatic and hydrodynamic bearing.

Rotatable building structure having fluid bearings

Abstract: A building structure having a central core portion supporting on fluid bearings a rotor portion which is rotatable about the core. The bearings may be aligned in a series of concentric circles or may be grouped in twos and threes in unique bearing sttuctures, allowing the rotor to be supported in a bearing pressurized mode or in an unpressurized mode. The invention includes a lateral bearing system to insure low friction rotation, a truss system positioned between the core and the rotor for spreading the load of the rotor and for providing a spacing to gain access to the bearings for maintenence, and a strut arrangement allowing the bearings to be pivoted for ease of replacement.

Centrifugal pumps having rotatable pole rings supported in contactless bearings

Abstract: Centrifugal pump having a pole ring for producing a rotating magnetic field which drives a second rotatable pole ring which is connected to impeller blading where the second pole ring is axially supported with respect to the first pole ring by a fluid bearing film.

Fluid bearing assembly

Abstract: A fluid bearing assembly for a machine is described which offers the advantages of reduced friction while maintaining a minimum flow rate of the working fluid. This is accomplished by including in the bearing assembly means for introducing pressurized fluid between bearing surfaces, and embedding a seal member directly in one of the bearing surfaces so as to surround the fluid inlet and extend completely between the latter and the outlet for the fluid.

Fluid bearing device

Abstract: A fluid bearing load supporting system having unidirectional and omnidirectional capabilities which embodies means for forming one or a plurality of fluid vortices for separating a body from a supporting surface by an intervening cushion of fluid, providing therewith an extremely low coefficient of friction that facilitates a conveyance of the body for the purposes of transportation, processing, treatment and the like.

Performance of gas-lubricated nonconforming pivoted-pad journal bearings and a flexibly mounted spiral-groove thrust bearing

Abstract: A test program was conducted to determine the performance characteristics of gas-lubricated nonconforming pivoted-pad journal bearings and a spiral-groove thrust bearing designed for the Brayton cycle rotating unit (BRU). Hydrostatic, hybrid (simultaneously hydrostatic and hydrodynamic), and hydrodynamic tests were conducted in argon gas at ambient pressure and temperature ranges representative of hydrostatic operation up to the 10.5-kWe BRU power-generating level. Performance of the gas lubricated bearings is presented, including hydrostatic gas flow rates, bearing clearances, bearing temperatures, and transient performance.

Pneumomechanical Critical Speed Control for Gas Turbine Engine Shafts.

Abstract: : The object of the subject program was to further evaluate the application of gas-lubricated foil bearings to control high-speed turbomachine shaft critical speeds and/or amplitude of excursion. The work was intended to expand upon previous efforts by (1) incorporating a simulated H.P. rotor to house the intershaft foil bearings such that various interaction effects could be assessed, and (2) evaluating a tension type foil intershaft bearing. A two rotor test rig which simulated the dynamic characteristics of a two spool aircraft gas turbine engine for testing tension type foil intershaft bearings was designed and constructed. Test results demonstrated that the simulated L.P. rotor could be operated through the region of the second critical speed with the foil intershaft bearings installed; whereas it could not if the foil bearings were not installed. Furthermore, the foil bearings attenuated all rotor amplitudes between the first and second critical speeds. Detrimental interaction effects between high and low speed rotors were not observed.

Hydrodynamic bearing for gyroscope - protruding spindle with non-moistening fluid sealing off bearing fluid film

Abstract: The gyroscope bearing has a spindle mounted in a housing from which it protrudes at one or both ends. A non-moistening fluid is used between the protruding ends and the housing as a seal for the film of fluid between spindle and housing. A recess between spindle and housing, holds a bubble of the fluid film, to allow this to expand and contract with temperature. The spindle can have a thrust washer at one end, with a peripheral V-groove, communicating via a radial canal with the bubble. A film of lubricant of low vaporising pressure can be outside alongside the non-moistening fluid, to prevent its vapourisation or delay it.

Rheology in lubrication

Abstract: The rheological effects on lubrication are discussed. The types of lubrication considered are thick film hydrodynamic lubrication and thin film elastohydrodynamic lubrication. The temperature-viscosity, viscoelastic, shear-thinning, and normal stess effects on the lubrication of journal bearings are analyzed. A graph of the pressure distribution of viscoelastic liquids in journal bearings is provided. Mathematical models are developed to define the effects of various properties of the lubricants on friction reduction.

Complaint Foil Gas Lubricated Bearing

Abstract: : A series of demonstration tests, similar to those required for engine qualification, were conducted on a gas turbine engine using gas lubricated complaint foil bearings. The engine operated successfully throughout the water ingestion and dust ingestion tests. When subjected to high-yaw maneuver rates, which subjected the bearings to high gyroscopic moment loads, the ultimate load capacity of the bearings was reached. When subjected to high vibration, structural resonance was incurred which amplified the input vibration at the bearing carrier. The forward journal bearing did not survive the test but its vibrational loading was 5 times what was originally intended. Results of the overtemperature test indicated that the present bearing coating is acceptable up to 550 deg F, but higher temperature coatings would be required if the bearings should be installed in new, advanced-design engines.