Showing papers on "Fluid bearing published in 1971"

Some experimental results on sphere and disk drag

Abstract: The drag on spheres and disks moving rectilinearly through an incompressible fluid has been measured for Reynolds numbers (Re) from 5 to 100,000. Test models were mounted on a carriage which rode along a linear air bearing track system. Tests were performed by towing the models through a channel filled with glycerine-water mixtures. Forces and moments on the models were sensed by strain gage transducers; hydrogen bubble flow visualization was utilized in relating these forces to the unsteady wake flows. Steady drag results agreed with existing data except for the disk at 100 < Re < 1000, in which the drag coefficient values were up to 50% below the level of existing data; drag force unsteadiness during steady motion was always <5% for the sphere and <3% for the disk. Sphere drag measurements under constant acceleration from rest showed the apparent mass concept to be valid (at high Re) until the sphere had traveled approximately one diameter, after which the quasi-steady drag (based on instantaneous velocity) showed good agreement with the actual drag. Interference effects of the sting supports used in these tests are discussed.

Ferrohydrodynamic low friction bearing

Abstract: A self-contained, full-film hydrodynamic bearing utilizing (1) the hydrodynamic properties of a ferrofluid (colloidal suspension of magnetic particles) to produce support pressures in the bearing by an applied viscous pumping action, and (2) the magnetic properties of the ferrofluid to retain the fluid within the bearing.

An air bearing conveyor

Abstract: Article handling apparatus including load supporting means in the form of air bearings mounted on decks and actuable to provide a film of air for supporting a load above the surface of the decks. Propulsion means, which may be in the form of conveyor belts, are associated with one or more of the decks and have extended and retracted positions respectively engageable with, and spaced from, a load supported above the surface of the decks on the film of air. The propulsion means may be actuable to an extended position in response to energization of the air bearings so that the path of movement of the load can be determined by energization of a particular group of air bearings, and the direction of movement along the path can then be determined by energization of the propulsion means.

Hydrodynamic foil bearings

Abstract: A hydrodynamic bearing system is provided wherein a resilient bearing insert structure is disposed within the spacing defined by the confronting surfaces of a first member (such as a housing with an opening) and a second member (such as a shaft received within the opening) which are movable (rotatable) relative to one another. The resilient bearing insert structure includes one or more bearing elements which are preformed (such as with corrugations of generally Z configuration) to provide one or more load supporting regions each of which includes two coacting operating portions one portion coacting with the rotating shaft to create a load supporting hydrodynamic fluid film and the other portion underlying and coacting with it to provide a tunable resilient supporting and damping means therefor.

Application Bulletin of the JSME of Finite-Element Method to Hydrodynamic Lubrication Problems : Part 1, Infinite-Width Bearings

Abstract: Few papers which applied the finite-element method to hydrodynamic lubrication have been published, in spite of many literatures introducing the finite-element method in structural problems. In this paper, the applications of the finite-element method for hydrodynamic lubrication of infinite-width bearings are presented. It is claimed that the finite-element method is able to obtain the accurate results by using a few elements. The finite-element solution is compared with an exact solution and a finite-difference solution of step bearings, plane slider learnings and journal bearings.

Replaceable air cushion device

Abstract: An air cushion load carrying device having one or more air bearings and providing for removal and replacement of an air bearing while the load carrying structure continues to support the load A load carrying member with a slide in and slide out construction for individual air bearings A load carrying member with an air distribution chamber and receptacles for one or more air bearings and air flow paths between the chamber and the bearings with a pressure seal construction providing ready insertion and removal of bearings

The current state of the art of fluid bearings with discrete slot inlets

Abstract: This paper is intended to present the current state of the art of a novel type of externally pressurized bearing, in which the supporting fluid is fed to the bearing gap through strategically positioned discrete slots, as opposed to orifices or capillaries The discrete slot formation lends itself to a wide variety of bearing configurations and shows to advantage in bearings of extremely low L/D ratios and also in small sizes A brief assessment of performance is presented together with some current applications Development of this bearing design is less than a decade old and much work is still to be undertaken In view, however, of current widespread interest in the UK by Government Departments, research groups, and commercial organizations, this paper attempts to describe development to date The concept of the bearing was conceived after fairly comprehensive study of the problems associated with the orifice design

Optimization of self-acting herringbone journal bearings for maximum radial load capacity

Abstract: Computer program for determination of optimal herringbone journal bearings for maximum radial load capacity

High speed hybrid bearing comprising a fluid bearing & a rolling bearing connected in series

Abstract: A rotating shaft is supported by a fluid bearing and a rolling element bearing coupled in series. Each bearing turns at a fraction of the rotational speed of the shaft. The fluid bearing is preferably conical, thereby providing thrust and radial load support in a single bearing structure.

Ferrohydrodynamic low-friction bearing with volume compensation

Abstract: A self-contained, full film hydrodynamic bearing is provided utilizing (1) the hydrodynamic properties of a ferrofluid (colloidal suspension of magnetic particles) to produce support pressures in the bearing by an applied viscous pumping action, and (2) the magnetic properties of the ferrofluid to retain the fluid within the bearing where the bearing retains the ferrofluid over a wide temperature range and concomitantly compensates for ferrofluid expansion and contraction.

Magnetic fluid pneumatic bearings

Abstract: A bearing assembly which includes a pin disposed within a housing and a magnetic fluid seals a fluid bearing pad between the outer surface of the pin and the inner surface of the housing. The sealed fluid bearing pad provides a pneumatic action in response to thrust forces acting on either the housing or the pin. A plurality of magnetic fluid rings are disposed externally of the sealed bearing pad and between the surfaces of the pin and housing to provide a radial restoring force between the pin and the housing when an offsetting force acts on either the pin or the housing. The rings serve an additional function in that they also provide a multi-stage seal for the fluid bearing pad.

High rigidity fluid bearings

Abstract: In a high rigidity fluid bearing of the type wherein a rotating shaft is supported by fluid under pressure contained in fluid pockets formed in the bearing surface in spaced apart relationship in the circumferential direction and surrounded by raised lands, the axial width of the lands is made narrower on the load side than on the no load side so as to cause more pressurized fluid to flow out from the pockets over the load side lands than over the no load side lands.

Critical speeds of a rotor in rigidly mounted, externally pressurized, air-lubricated bearings

Abstract: Calculation of rotor critical speeds for two bearing rotor system from rigid body theory using film stiffness as determined from zero speed, load eccentricity data

Experiments on the stability of water lubricated three lobe hydrodynamic journal bearings at zero load

Abstract: Water-lubricated three-lobe hydrodynamic journal bearing stability tests at zero load with and without axial grooves

Axial piston pump or motor

Abstract: A hydraulic axial piston device having a flat bearing plate interposed between the cam surface and piston outer ends The bearing plate and a pilot radially guiding the bearing plate rotate in synchronization with the pistons The pilot is joined to the shaft, whereby the side forces on the bearing plate are transmitted to the shaft In one embodiment the bearing plate forms the race of an antifriction roller bearing in engagement with outer spherical piston ends In still another embodiment the bearing plate is in engagement with piston slipper shoes and provides a hydrostatic fluid bearing surface for absorbing piston axial thrust Fluid porting may be provided through the bearing plate

Magnetic fluid bearing

Abstract: The invention comprises several related embodiments of a basic rotary thrust bearing. The present bearings provide stability in three planes, the thrust capability thereof being derived from the compressive reaction of a hermetically sealed fluid held between stationary and rotating thrust plates. Essentially, a stationary thrust plate of the present bearing comprises an annular magnet having concentric magnetically permeable pole members disposed therearound, which pole members have raised bevels at respective ends facing a rotating thrust plate. The rotating thrust plate comprises an annular plate having concentric raised bevels opposing the bevels on the stationary thrust plate, a magnetic fluid being magnetically held between the annular apices of the respective bevels for trapping a fluid within a chamber defined by the bevels.

Radial fluid bearing

Abstract: The invention comprises related embodiments of a basic rotary bearing having primarily effective sealing and either radial loading or thrust loading. Journaling capability is realized by holding a stationary annular member having a substantially triangularly cross-sectional flange within a high density fluid centrifugally retained within a rotary annular cavity. Imposition of a radial load on the structure biases the stationary annular member into the fluid until the buoyant force exerted on said member by the fluid equals the imposed load. In another embodiment having thrust loading capability, the stationary member comprises a disc-like thrust plate held within a rotating cavity, the outer annular edges of the plate being immersed in a fluid held along the inner periphery of the cavity by the rotary motion thereof.

Turbine alternator utilizing fluid bearings

Abstract: A turbine alternator for use in ordnance projectiles that obviates the need for mechanical bearings as journal means therefor. The moving part of the alternator is maintained in the proper position by a pressure differential created by the ram pressure developed by the projectile as it moves through the fluid medium in accordance with a well-known law of physics known as Bernoulli''s Principle. The electrical output from the alternator can be used as a power source in a conventional bomb, rocket or similar projectile. The elimination of the expensive and fragile mechanical bearings provides an unlimited operational life for the alternator.

Spindle assembly air bearings

Abstract: A spindle assembly includes a sleeve bearing having a number of air nozzles equi-angularly arranged about a shaft. A thrust bearing supports one end of the shaft with clearances for air support. The air nozzles generally have a frusto-conical air passage with a central bore.

Journal bearing assembly for counter-rotating shafts

Abstract: 1,236,399. Bearing for counter-rotating shafts. GLACIER METAL CO. Ltd. 16 Sept., 1968 [12 Sept., 1967], No. 41624/67. Heading F2A. A hollow shaft 1 is journalled in a sleeve 7 by a hydrodynamic fluid bearing, and another shaft 2 is journalled within the outer shaft by a hydrostatic bearing to which fluid is fed from the hydrodynamic bearing. Passages 9 extend from one bearing to the other to convey the lubricant. The two bearings may be axially coextensive, or the surface of the inner bearing may be provided with axial passageways for distributing lubricant.

An Investigation of Air Bearings for Gas Turbine Engines

Abstract: : Due to ascending performance conditions and accompanying high rotational speeds, increasingly severe operating requirements will be imposed on main engine bearings and seals. Conventional oil lubrication techniques may not be adaptable to the next generation of small engines. This report presents a summary of the results of work performed during Phase I of an investigation of air bearings for gas turbine engines. Results of a study of the significant effects of engine size on the design feasibility of air bearings show that the engine size over a range of from 2 to 5 lb/sec design-point air flow is not a significant factor with respect to air-bearing feasibility. However, the types of compressor and turbine components selected as well as their arrangement will influence the feasibility.

Performance Factors for Circular, Hydrostatic, Gas-Lubricated Thrust Bearings. Part II. Multiple Inlet Thrust Bearings,

Abstract: : A general design procedure for multiple-inlet gas thrust bearings was derived. Dimensionless load and flow factors were calculated for a wide range of bearing parameters using a conformal transformation procedure proposed by Mori and Yabe. These factors are combined with empirical correlations for the bearing entry losses to provide a simple, convenient design procedure. The predicted performances are compared with a number of experimental studies. The results indicate: good agreement for both flow and load prediction with orifice-compensated bearings; fair agreement for load prediction but poor agreement for flow prediction with inherently-compensated bearings. The reasons for the latter discrepancy are discussed. (Author)