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Results for “Electromechanics”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Automatic bio-sample bacteria detection system

Electromechanical device analyzes urine specimens in 15 minutes and processes one sample per minute. Instrument utilizes bioluminescent reaction between luciferase-luciferin mixture and adenosine triphosphate (ATP) to determine number of bacteria present in the sample. Device has potential application to analysis of other body fluids.

Chappelle, E. W.↗
NASA NTRS1971

Improved wax mold technique forms complex passages in solid structures

Low-cost fabricating technique produces minute, complex air passages in fluidic devices. Air jet interactions in these function as electronic and electromechanical control systems. Wax cores are fabricated without distortion by two-wax process using nonsoluble pattern-wax and water-soluble wax. Significant steps in fabrication process are discussed.

Hellbaum, R. F.↗
NASA NTRS1972

Current switch has built-in time delay: A concept

Switch concept provides simple means of achieving electromechanical time delay function. Unit consists of reed-type circuit breaker enclosed by copper tubing with electromagnetic coil wound around tubing and entire assembly mounted on insulating platform. Characteristics are affected only by geometry of system so device is expected to be very stable.

Jesch, C. D.↗
NASA NTRS1971

Meeting the challenge of a 50000-hour-life-time requirement

Space mission requirements for the 70's have established a 50,000-hour-lifetime challenge for the mechanisms designer. This challenge may be met by two approaches: (1) development of new materials for wear-prone elements, and (2) design innovation of new electromechanical devices that do not include mechanical wear-prone components. Present state-of-the-art materials require restricted operation regarding load, speed, and power for gears, bearings, and brush-slipring components. These restrictions are discussed, and methods of improvement are suggested. The design-innovations approach is discussed and is illustrated by the design of an experimental magnetically suspended motor.

Vest, C. E.↗
NASA NTRS1971

The Mariner Mars 1971 gimbal actuator

The actuator that will point the gimbaled engine, thus performing the autopilot actuation function for the Mariner Mars 1971 spacecraft, is described. The gimbaled engine has two axes of freedom, providing two-axis control to the spacecraft. Motion for the two axes is provided by identical and interchangeable actuators-gearless electromechanical linear servomechanisms. Each actuator is designed to have a long service life in the space environment and to be able to function at speeds ranging from hours per cycle to cycles per second.

Perkins, G. S.↗
NASA NTRS1971

Saturn component failure rate and failure rate modifiers

Failure mode frequency ratios, environmental adjustment factors, and failure rates for mechanical and electromechanical component families are presented. The failure rates and failure rate modifiers resulted from a series of studies whose purpose was to provide design, tests, reliability, and systems engineers with accurate, up-to-date failure rate information. The results of the studies were achieved through an extensive engineering analysis of the Saturn Program test data and Unsatisfactory Condition Reports (UCR's) and the application of mathematical techniques developed for the studies.

Source record↗
NASA NTRS1972

Electro-mechanical sine/cosine generator

An electromechanical device for generating both sine and cosine functions is described. A motor rotates a cylinder about an axis parallel to and a slight distance from the central axis of the cylinder. Two noncontacting displacement sensing devices are placed ninety degrees apart, equal distances from the axis of rotation of the cylinder and short distances above the surface of cylinder. Each of these sensing devices produces an electrical signal proportional to the distance that it is away from the cylinder. Consequently, as the cylinder is rotated the outputs from the two sensing devices are the sine and cosine functions.

Flagge, B.↗
NASA NTRS1972

Long-life, space-maintainable nuclear stage regulators and shutoff valves

The six most promising valve, regulator, and remote coupling concepts, representing the more radical designs from twenty concepts generated, were investigated. Of the three valves, one has no moving parts because shutoff sealing is accomplished by an electromagnetic field which ionized the flowing fluid. Another valve uses liquid metal to obtain sealing. In the third valve, high sealing forces are generated by heating and expanding trapped hydrogen. The pressure regulator is an electronically controlled, electromechanically operated, single state valve. Its complexity is in electronic circuitry, and the design results in less weight, increased reliability and performance flexibility, and multipurpose application. The two remote couplings feature the minimization of weight and mechanical complexity. One concept uses a low melting temperature metal alloy which is injected into the joint cavity; upon solidification, the alloy provides a seal and a structural joint. The second concept is based on the differential thermal expansion of the coupling mating parts. At thermal equilibrium there is a predetermined interference between the parts, and sealing is achieved by interference loading.

Source record↗
NASA NTRS1972

Pulse performance analysis for small hypergolic-propellant rocket engines

Small rocket engine tests were conducted for the purpose of obtaining pulse performance data to aid in preliminary design and evaluation of attitude control systems. Both monopropellant and hypergolic bipropellant engines of thrust levels from 1 to 100 lbs were tested. The performance data for the hypergolic propellant rockets are compared with theoretical performance calculated from idealized chamber filling and evacuation characteristics. Electromechanical delays in valve response and heat transfer characteristics were found to cause substantial deviation between theoretical and test performance. The theoretical analysis is modified to obtain a semi-empirical model for hypergolic propellant rockets which is demonstrated to be reasonably accurate for two different engine configurations over a considerable range of duty cycles.

Smith, G. W.↗
NASA NTRS1972

Analysis and design of a capsule landing system and surface vehicle control system for Mars exporation

The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement and transport parameter evaluation.

Frederick, D. K.↗