Showing papers on "Fluid bearing published in 1980"

Hydrodynamic support bearing for a belt on a tire testing machine

Abstract: A bearing support for a flexible belt used on a tire testing machine wherein the belt forms the simulated road surface. The bearing is a hydrodynamic bearing which insures low friction between the belt and its support underneath the tire being tested.

Dynamic pressure type fluid bearing

Abstract: PURPOSE: To ensure reliability and life of a fluid bearing by coating the bearing surfaces of the pars concerned with ceramics, fitting the parts loose with a minute gap, and by providing one of the members with a dynamic pressure generating groove to be used for local shot blasting of the coated areas. CONSTITUTION: The bearing face 11 of the moving member 1 is coated with ceramics 111 in a thickness equal to the depth of a dynamic pressure generating spiral groove 112 while the bearing face 21 of the stationary member 2 is coated with ceramics 221 evenly. A cap 31 of iron plate having such configuration and dimensions as fittable to the bearing surface 11 is provided with a through hole 33 having such confuguration and dimensions as fittable to the groove 112, and all the surface but this hole 33 is covered with rubber etc. to form a mask 3 and to fit on the bearing face 11, and then fine-particle shot blasting shall be applied normally to the hole 33 to form groove 112. According to this procedure, the groove 112 will be free of side etching, and the resulting sharp profile ensures the bearing performance well conforming to the calculations. COPYRIGHT: (C)1982,JPO&Japio

Air bearing for use with concentric rotary shafts in machines

Abstract: U.S. Pat. No. 4,118,079 discloses a fluid bearing in which resilient shells are bent during operation of the bearing in response to changes in pressure of the fluid to make them conform more closely to the confronting surface defining the fluid gap. In the present invention a bearing of this type is used as an intershaft bearing by mounting the shells on one of the rotating shafts the problems associated with centrifugal forces on the shells being turned to advantage by mounting the shells on an external surface of one of the shafts to confront an internal surface on the other shaft. In an application of the invention to a gas turbine engine the two shafts are the high pressure shaft 10 and the concentric inner low pressure shaft 12. The bearing shells 34 of the air bearing 32 are mounted on resilient spring levers 36 on the slower low pressure shaft 12 and their convex surfaces confront the concave internal surface of the high pressure shaft 10, to define the air gap. The spring levers together with the centrifugal forces on the shells modify the shapes of the shells in response to air pressure in the gap to improve the load carrying capacity of the bearing. The shafts contra rotate to maximize relative rotational speed of the surfaces.

Magnetic seal device

Abstract: PURPOSE:To maintain the sealing of a lubricant fluid for a long time without impairing the load characteristics of a device by the method wherein a magnetic fluid of low viscosity is used as lubricant oil for the fluid bearing and a fluid of high viscosity is used as magnetic seal in a high-precision rotary device, such as a VTR cylinder CONSTITUTION:By the ''barrier'' formed by sealing magnetic fluid 8 of low volatility, magnetic fluid 5 of high volatility is shut off from the atmosphere outside the device, and the voltatilization of magnetic fluid 5 can be confined to the small volume of gap 13 As a result, a fixed amount of lubricant magnetic fluid 5 can be kept at the oil film part of the fluid bearing at all times even after a long time of disuse Further, the space between lubricant magnetic fluid 5 and sealing magnetic fluid 8 is sealed by two magnets 6, 9 Moreover, since air gap 13 is provided between them, contact between magnetic fluids 5, 8 is prevented By this, it is possible to maintain stable rotational characteristics for a long time even under the bad circumstance of low torque

Turbodrill with rubber rotor bearings

Abstract: A turbodrill which is connected to a string of drill pipe as a rotating shaft for driving a drill bit which may be a rotary bit or a high speed solid head diamond bit. The turbine section has rotor and stator blades which are cresent shaped in cross section with each blade having an exit angle of 14°-23° for maximum turbine efficiency. The bearing shaft is provided with chevron rotary seals positioned below the rotary bearings carrying both radial and vertical thrust. Fluid lubricant fills the space from the rotary seals to a predetermined level above the bearings. A piston seals the lubricant chamber and is pressurized by drilling fluid (i.e. mud) flowing through the tool. A layer of lubricant fluid overlies the first piston and has a second piston covering said fluid and transmitting pressure from the drilling fluid to the lubricant fluid surrounding the bearings. Rubber friction bearings which are cooled and lubricated by flow of drilling mud are provided between the rotor and stator bearing surfaces which provide for extended rotor bearing life and cushion the radial thrust bearings against radial shock and provide for a substantially extended life for the radial thrust bearings.

On the mathematical theory of porous metal bearings

Abstract: The hydrodynamic lubrication of a porous metal bearing is studied from a rigorous mathematical point of view. We use mainly the theory of the elliptic unilateral problems.

Pneumatic tension sensor

Abstract: A tension sensor is placed within a fluid bearing supporting a flexible tape at least partially wrapped around the periphery thereof. The bearing includes a source of pressurized fluid, such as air, and a plurality of metered orifii for admitting fluid into the region of the periphery to support the tape on a fluid bearing. The sensor includes a chamber and at least two metered orifice means, one in communication with the region of pressurized fluid supporting the tape and the other in communication with the source of pressurized fluid. A pressure sensor senses the pressure within the chamber, the pressure being directly proportional to the tension in the tape.

Applications of air bearings and optics

Abstract: Integration of interferometry and air bearing technology is the corner stone of some modern precision machine design. In this article P. Langenbeck∗ summarises the main characteristics of aerostatic bearings and optical measuring systems and describes some applications

Ring rail with air-suspended spinning or twisting rings

Abstract: A new ring rail having air-suspended spinning or twisting rings suspended in air bearings is proposed, the improvement residing in that an intermediate ring is releasably connected to a bearing stator in an outer ring and thus can be quickly exchanged at any time.

Self regulating air bearing

Abstract: A fluid bearing having improved operating characteristics. The platform to which the bearing is attached and which supports any load includes the necessary conduits for supply of fluid under pressure as well as the necessary structural integrity to support the expected load. The conduits are, with respect to the bearing and the plenum area of the bearing, in a particular, predetermined relative location. When the bearing is in a deflated condition and fluid under pressure is introduced, the initial fluid flows into the bearing and the plenum at a predetermined rate. The deflated bearing structure restricts fluid flow into the plenum until after the bearing is substantially inflated. The controlled flow to the bearing and the plenum allows a substantial pressure differential between the interior of the bearing and the plenum. Upon reaching inflation, fluid under pressure can freely flow into the bearing, into the plenum and between the plenum and the interior of the bearing.

Rotor-Bearing Dynamics Technology Design Guide. Part V. Dynamic Analysis of Incompressible Fluid Film Bearings.

Abstract: : This report gives the equilibrium position, bearing coefficients, friction torque, and oil flow for plain journal, multilobe, and tilting pad journal bearings. For multilobe bearings, various combinations of preload, number of pads, and load direction are evaluated. Tilting pad bearings are analyzed for various combinations of length to diameter ratio, preload, number of pads, and load direction. (Author)

Effect of Roughness in the Form of Pits or Pockets on the Lubrication of Slider Bearings

Abstract: The theoretical effects upon hydrodynamic lubrication of a two-dimensionally distributed roughness pattern, consisting of pits or pockets in a flat, are described. The analysis is based upon the author's recent numerical work on doubly periodic roughness. The main attention is paid to bearings of a stationary roughness pattern, and it is shown that the friction as well as load capacity are increased, the latter particularly in connection with narrow bearing geometries for which the coefficient of friction may be considerably lowered. The theoretical findings are shown to be easily explainable on physical grounds.

Hydrodynamic bearing system

Abstract: A bearing system, comprising two parts (4), (5) which are rotatable with respect to each other and which have bearing surfaces that cooperate with one another in the radial direction and/ortwo opposing axial directions at least one bearing surface of each pair of cooperating bearing surfaces being provided with a pattern of shallow lubricant pumping grooves (7), the two rotatable parts being made of materials or material combinations chosen so that, as the temperature rises, the gap between the bearing surfaces becomes smaller duetothe different thermal expansion of the relevant parts.