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Transmitter allows transmission of rotational or single planar arc motion through hermetically sealed chamber without use of dynamic seals or complex mechanisms. Device may interest pressure vessel designers and those who need to isolate equipment from a hostile environment.
Aluminum sheet forms effective sealing film at temperatures up to 728 K. Soft aluminum wire rings provide positive seal between foil and platen. For applications at temperatures above aluminum's service temperature, stainless steel is used as film material and copper wire as sealant.
Design and performance of gas-film and oil-film lubricated self sealing mainshaft seals for gas turbine engines
Hydrostatic life-off seal zero leakage and static sealing and rubbing tests for use in liquid hydrogen turbine pumps
Seal surface profiles of DuPont LRU 488 molded elastomeric seat seals
Shaft riding circumferential seal is used with turbine engines under high pressure conditions. Construction of seal is discussed and schematic diagram to show operations is provided.
FORTRAN 4 program for use on IBM 7094 computer for calculating temperature field of shaft seals is described. Shaft seals are composed of basically axisymmetric bodies. Cylindrical coordinate system is used as basis for analysis. Program is quite general and can be applied to variety of axisymmetric body problems.
Program calculates mass and volume leakage across seal; mean friction factor; force; center of pressure; and distributions of pressure, temperature, density, friction parameter, velocity, and Mach number across seal for both laminar flow and turbulent flow regimes and for choked and subsonic flow.
Compress soft, inert metal gasket between cone and corresponding socket to attach tubes to vessels containing gas samples. Technique effects seals with minimum of applied force and does not contaminate contents. Seal is formed when port connector is pushed firmly into its socket. Gold washer is deformed and forced to flow into imperfections in surfaces.
Silicon members are hermetically sealed to each other. Process produces no measurable deformation of silicon surfaces and is compatible with package designs of tight tolerance. Seals have been made with glass coatings in 10-mm to 20-mm thickness range without any prior annealing of coated silicon substrates.
The design, construction, and testing of 100,20Ah and 100,3Ah negative-limited sealed cells are reported. The required physical dimensions of the hardware and components necessary to produce 20 and 3 Ah cells were established. The stainless steel cans and covers have been ordered. The covers contain two ceramic seals. The fabrication of electrodes was started. About 55% (879 electrodes) of the required cadmium electrodes has been prepared. About 44% of the porous nickel substrates (plaques) required for the preparation of the nickel oxide electrodes has been completed.
The sealing techniques are studied for existing aircraft wheel-tire designs to meet the hard vacuum .00001 torr and cold temperature -65 F requirements of space travel. The investigation covers the use of existing wheel seal designs.
A computer program is presented for compressible fluid flow with friction and area change. The program carries out a quasi-one-dimensional flow analysis which is valid for laminar and turbulent flows under both subsonic and choked flow conditions. The program was written to be applied to gas film seals. The area-change analysis should prove useful for choked flow conditions with small mean thickness, as well as for face seals where radial area change is significant. The program is written in FORTRAN 4.
A two year study of the major process variables associated with the manufacturing process for sealed, nickel-cadmium, areospace cells is summarized. Effort was directed toward identifying the major process variables associated with a manufacturing process, experimentally assessing each variable's effect, and imposing the necessary changes (optimization) and controls for the critical process variables to improve results and uniformity. A critical process variable associated with the sintered nickel plaque manufacturing process was identified as the manual forming operation. Critical process variables identified with the positive electrode impregnation/polarization process were impregnation solution temperature, free acid content, vacuum impregnation, and sintered plaque strength. Positive and negative electrodes were identified as a major source of carbonate contamination in sealed cells.
The basic aspect of parallel-surface lubrication that distinguishes it from other areas of lubrication technology is that classical lubrication theory does not predict the existence of a stable hydrodynamic film for steady-state, isothermal, incompressible flow between smooth, parallel surfaces. Hydrodynamic films between apparently parallel surfaces have been observed in practice and are often essential for the reliable performance of thrust bearings and seals. In order to account for this fortunate discrepancy between classical theory and experiment, load-support mechanisms relating to accidential features characteristic of seal performance, which relax one or more of the assumptions in the classical theory and permit the theoretical prediction of load support are proposed. Some of the features that have been analyzed are vibratory effects such as wobble and bounce, surface waviness, nonsymmetric rotation resulting from various types of misalignment, lubricant density change, non-Newtonian lubricant effects, and surface roughness.
Negative-limited sealed nickel-cadmium cells are a possible means toward increasing the life of nickel-cadmium cells to about a decade or more. The purpose of this program is to design, construct, and test 100, 20 Ah and 100, 30 Ah negative-limited sealed cells. The cell design was completed and hardware was ordered during the first quarter. Electrode fabrication was started in the first quarter and carried on through the second quarter. The fabrication and selection of the necessary electrodes has been completed during the third quarter. Cell construction has been completed and the preparatory cell cycling is underway. The preliminary testing to select the initial delivery cell has been started.
Guide is based on experience obtained in wide variety of applications using lip, circumferential, and face seals. Particular attention is given to capabilities and lubrication of various seal types. Special limitations as a result of storage requirements, quality control, installation, operation, and removal are discussed.
Seals are designed for use with liquid propellant ball valves at temperatures ranging from -400 F to 130 F and 8,000 psig. Seals are capable of sustaining 90 degree rotation, with substantial amount of lateral and axial play, caused by large pressure loads and differential thermal contraction.