Search NASA⌕ Search

SEARCH · Search NASA

Results for “TORQUE MEASURING APPARATUS”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Loadcell supports for a dynamic force plate

An apparatus was developed to accurately measure components of force along three mutually perpendicular axes, torque, and the center of pressure imposed by the foot of a subject walking over its surface. The data obtained were used to supplement high-speed motion picture and electromyographic (EMG) data for in-depth studies of normal or abnormal human gait. Significant features of the design (in particular, the mechanisms used to support the loadcell transducers) are described. Results of the development program and typical data obtained with the device are presented and discussed.

Keller, C. W.↗
NASA NTRS1970

Automatic, computerized testing of bolts

System for testing bolts with various platings, lubricants, nuts, and tightening procedures tests 200 fasteners, and processes and summarizes the results, within one month. System measures input torque, nut rotation, bolt clamping force, bolt shank twist, and bolt elongation, data is printed in report form. Test apparatus is described.

Carlucci, J., Jr.↗
NASA NTRS1973

Study of ball bearing torque under elastohydrodynamic lubrication

Spinning and rolling torques were measured in an angular-contact ball bearing with and without a cage under several lubrication regimes in a modified NASA spinning torque apparatus. Two lubricants were used, a di-2 ethylhexyl sebacate and a synthetic paraffinic oil, at shaft speeds of 1000, 2000, and 3000 rpm and bearing loads from 10 lbs to 90 lbs. An analytical model was developed from previous spinning friction models to include rolling with spinning under lubrication regimes from thin film to flooded conditions. The bearing torque values have a wide variation, under any condition of speed and load, depending on the amount of lubricant present in the bearing. The analytical model compared favorably with experimental results under several lubrication regimes.

Townsend, D. P.↗
NASA NTRS1973

Study of ball bearing torque under elastohydrodynamic lubrication

Spinning and rolling torques were measured in an angular-contact ball bearing with and without a cage under several lubrication regimes in a modified NASA spinning torque apparatus. Two lubricants were used - a di-2 ethylhexyl sebacate and a synthetic paraffinic oil, at shaft speeds of 1000, 2000, and 3000 rpm and bearing loads from 45 newtons (10 lb) to 403 newtons (90 lb). An analytical model was developed from previous spinning friction models to include rolling with spinning under lubrication regimes from thin film to flooded conditions. The bearing torque values have a wide variation, under any condition of speed and load, depending on the amount of lubricant present in the bearing. The analytical model compared favorably with experimental results under several lubrication regimes.

Townsend, D. P.↗
NASA NTRS2002

Transient Torque Technique for Viscosity and Electrical Conductivity Determination of Semiconducting Liquids

A novel apparatus based on transient torque technique is constructed in MSFC/NASA. The apparatus uses a 125um diameter quartz fiber as torsion wire. A high sensitive angular detector is implemented to measure the deflection angle of the crucible containing the liquid. A rotating magnetic field (RMF) is used to induce a rotating flow of a conducting or semiconducting melts. By measuring the magnitude and transient behavior of the induced deflection angle, the electrical conductivity and viscosity of the melt can be measured simultaneously. High purity elements namely Hg, Ga, Zn and Te are tested at room temperature and high temperature up to 900 C.

Li, C.↗
NASA NTRS2002

Technique for Determining the Viscosity and Electrical Conductivity of Semiconducting Liquids

A novel apparatus for determining the viscosity and electrical conductivity of semiconducting liquids has been developed at NASA/MSFC. The apparatus is based on the transient torque technique and utilizes a 125 micrometer diameter quartz fiber as a torsion wire and a sensitive angular detector to measure the deflection angle of the crucible containing the liquid. A rotating flow is induced in the semiconducting melt by the application of a rotating magnetic field and measurement of the magnitude and transient behavior of the induced deflection angle allows the simultaneous determination of the viscosity and electrical conductivity of the melt. Measurements at room temperature and up to 900 C were made on high purity melts.

Li, C.↗
NASA NTRS1973

A study of the dynamic tire properties over a range of tire constructions

The dynamic properties of four model aircraft tires of various construction were evaluated experimentally and compared with available theory. The experimental investigation consisted of measuring the cornering force and the self-aligning torque developed by the tires undergoing sinusoidal steering inputs while operating on a small scale, road-wheel tire testing apparatus. The force and moment data from the different tires are compared with both finite- and point-contact patch string theory predictions. In general, agreement between finite contact patch theory and experimental observation is good. A modified string theory is also presented in which coefficients for cornering force and self-aligning torque are determined separately. This theory improves the correspondence between the experimental and analytical data, particularly on tires with relatively high self-aligning torques.

Nybakken, G. H.↗
NASA NTRS2005

An Oil-Free Thrust Foil Bearing Facility Design, Calibration, and Operation

New testing capabilities are needed in order to foster thrust foil air bearing technology development and aid its transition into future Oil-Free gas turbines. This paper describes a new test apparatus capable of testing thrust foil air bearings up to 100 mm in diameter at speeds to 80,000 rpm and temperatures to 650 C (1200 F). Measured parameters include bearing torque, load capacity, and bearing temperatures. This data will be used for design performance evaluations and for validation of foil bearing models. Preliminary test results demonstrate that the rig is capable of testing thrust foil air bearings under a wide range of conditions which are anticipated in future Oil-Free gas turbines. Torque as a function of speed and temperature corroborates results expected from rudimentary performance models. A number of bearings were intentionally failed with no resultant damage whatsoever to the test rig. Several test conditions (specific speeds and loads) revealed undesirable axial shaft vibrations which have been attributed to the magnetic bearing control system and are under study. Based upon these preliminary results, this test rig will be a valuable tool for thrust foil bearing research, parametric studies and technology development.

Bauman, Steve↗
NASA NTRS1927

The Direct Measurement of Engine Power on an Airplane in Flight with a Hub Type Dynamometer

This report describes tests made to obtain direct measurements of engine power in flight. Tests were made with a Bendemann hub dynamometer installed on a modified DH-4 Airplane, Liberty 12 Engine, to determine the suitability of this apparatus. This dynamometer unit, which was designed specially for use with a liberty 12 engine, is a special propeller hub in which is incorporated a system of pistons and cylinders interposed between the propeller and the engine crankshaft. The torque and thrust forces are balanced by fluid pressures, which are recorded by instruments in the cockpit. These tests have shown the suitability of this type of hub dynamometer for measurement of power in flight and for the determination of the torque and power coefficients of the propeller. (author)

Gove, W D↗
NASA NTRS1999

Methods of Viscosity Measurements in Sealed Ampoules

Viscosity of semiconductor and metallic melts is usually measured by oscillating cup method. This method utilizes the melts contained in vacuum sealed silica ampoules, thus the problems related to volatility, contamination, and high temperature and pressure can be alleviated. In a typical design, the time required for a single measurement is of the order of one hour. In order to reduce this time to a minute range, a high resolution (0.05 arc.sec) angular detection system is implemented in our design of the viscometer. Furthermore, an electromagnet generating a rotational magnetic field (RMF) is incorporated into the apparatus. This magnetic field can be used to remotely and non intrusively measure the electrical conductivity of the melt. It can also be used to induce a well controlled rotational flow in the system. The transient behavior of this flow can potentially yield the viscosity of the fluid. Based on RMF implementation, two novel viscometry methods are proposed in this work: a) the transient torque method, b) the resonance method. A unified theoretical approach to the three methods (oscillating cup, transient torque, and resonance) is presented along with the initial test results of the constructed apparatus. Advantages of each of the method are discussed.

Mazuruk, Konstantin↗
NASA NTRS1977

First-order torques and solid-body spinning velocities in intense sound fields

The letter reports an observation of first-order nonzero time-averaged torques and solid-body spinning velocities in intense acoustic fields. The experimental apparatus consisted of a vertical cylindrical rod supported on an air bearing and passing through a box with two loudspeakers centered on adjoining vertical sides. The rim velocity of the cylinder and the torque on the cylinder are measured as functions of air-particle velocity and the phase difference between the x and y components of the particle velocity. It is found that both rim velocity and torque are linear functions of particle velocity. Difficulties in constructing a proper theoretical description of the observed effects are discussed.

Wang, T. G.↗
NASA NTRS1992

Measurement of multiaxial ply strength by an off-axis flexure test

An off-axis flexure (OAF) test was performed to measure ply strength under multiaxial stress states. This test involves unidirectional off-axis specimens loaded in bending, using an apparatus that allows these anisotropic specimens to twist as well as flex without the complications of a resisting torque. A 3D finite element stress analysis verified that simple beam theory could be used to compute the specimen bending stresses at failure. Unidirectional graphite/epoxy specimens with fiber angles ranging from 90 deg to 15 deg have combined normal and shear stresses on their failure planes that are typical of 45 deg plies in structural laminates. Tests for a range of stress states with AS4/3501-6 specimens showed that both normal and shear stresses on the failure plane influenced cracking resistance. This OAF test may prove to be useful for generating data needed to predict ply cracking in composite structures and may also provide an approach for studying fiber-matrix interface failures under stress states typical of structures.

Crews, John H., Jr.↗
NASA NTRS2009

NASA Tech Briefs, November 2009

Topics covered include: Cryogenic Chamber for Servo-Hydraulic Materials Testing; Apparatus Measures Thermal Conductance Through a Thin Sample from Cryogenic to Room Temperature; Rover Attitude and Pointing System Simulation Testbed; Desktop Application Program to Simulate Cargo-Air-Drop Tests; Multimodal Friction Ignition Tester; Small-Bolt Torque-Tension Tester; Integrated Spacesuit Audio System Enhances Speech Quality and Reduces Noise; Hardware Implementation of a Bilateral Subtraction Filter; Simple Optoelectronic Feedback in Microwave Oscillators; Small X-Band Oscillator Antennas; Free-Space Optical Interconnect Employing VCSEL Diodes; Discrete Fourier Transform Analysis in a Complex Vector Space; Miniature Scroll Pumps Fabricated by LIGA; Self-Assembling, Flexible, Pre-Ceramic Composite Preforms; Flight-speed Integral Image Analysis Toolkit; Work Coordination Engine; Multi-Mission Automated Task Invocation Subsystem; Autonomously Calibrating a Quadrupole Mass Spectrometer; Determining Spacecraft Reaction Wheel Friction Parameters; Composite Silica Aerogels Opacified with Titania; Multiplexed Colorimetric Solid-Phase Extraction; Detecting Airborne Mercury by Use of Polymer/Carbon Films; Lattice-Matched Semiconductor Layers on Single Crystalline Sapphire Substrate; Pressure-Energized Seal Rings to Better Withstand Flows; Rollerjaw Rock Crusher; Microwave Sterilization and Depyrogenation System; Quantifying Therapeutic and Diagnostic Efficacy in 2D Microvascular Images; NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells; Critical Coupling Between Optical Fibers and WGM Resonators; Microwave Temperature Profiler Mounted in a Standard Airborne Research Canister; Alternative Determination of Density of the Titan Atmosphere; Solar Rejection Filter for Large Telescopes; Automated CFD for Generation of Airfoil Performance Tables; Progressive Classification Using Support Vector Machines; Active Learning with Irrelevant Examples; A Data Matrix Method for Improving the Quantification of Element Percentages of SEM/EDX Analysis; Deployable Shroud for the International X-Ray Observatory; Improved Model of a Mercury Ring Damper; Optoelectronic pH Meter: Further Details; X-38 Advanced Sublimator; and Solar Simulator Represents the Mars Surface Solar Environment.

Source record↗
NASA NTRS2006

Improved Apparatus for Testing Monoball Bearings

A desk-sized apparatus for testing monoball bearings and their lubricants offers advantages, relative to prior such apparatuses, of (1) a greater degree of automation and (2) capability of operation under wider and more realistic ranges of test conditions. The ranges of attainable test conditions include load from 100 to greater h than 50,000 lb (445 to greater than 2.22 x 10(exp 5) N), resisting torque up to 30,000 lb-in. (approximately equal to 3,390 N-m), oscillating rotation through an angle as large as 280 degrees, and oscillation frequency from 0 to 6 Hz. With addition of some components and without major modification of the apparatus, it is also possible to perform tests under environmental conditions that include temperature from -320 to 1,000 F (-196 to +538 C), relative humidity from 0 to 100 percent, and either air at ambient pressure, high vacuum, or an atmosphere of monatomic oxygen. In the apparatus (see Figure 1), a monoball bearing specimen is driven in oscillating rotation by a hydraulic rotary actuator through a series of shafts, one of which incorporates a torque meter and one of which is a flexible coupling. The torque meter measures the resisting torque; the flexible coupling accommodates misalignment, wear, and compression of the specimen and ensures equal loading on opposite sides of the monoball. Not shown in the figure is an angular-position sensor that is used for measuring the angle of rotation of the shafts.

Hall, Phillip B.↗
NASA NTRS1995

NASA Tech Briefs, November 1995

The contents include: 1) Mission Accomplished; 2) Resource Report: Marshall Space Flight Center; 3) NASA 1995 Software of the Year Award; 4) Microbolometers Based on Epitaxial YBa2Cu3O(sub 7-x) Thin Films; 5) Garnet Random-Access Memory; 6) Fabrication of SNS Weak Links on SOS Substrates; 7) High-Voltage MOSFET Switching Circuit; 8) Asymmetric Switching for a PWM H-Bridge Power Circuit; 9) Better Ohmic Contacts for InP Semiconductor Devices; 10) Low-Bandgap Thermovoltaic Materials and Devices; 11) Digital Frequency-Differencing Circuit; 12) Imaging Magnetometer; 13) Computer-Assisted Monitoring of a Complex System; 14) Buffered Telemetry Demodulator; 15) Compact Multifunction Inspection Head; 16) Optical Detection of Fractures in Ceramic Diaphragms; 17) Eddy-Current Detection of Cracks in Reinforced Carbon/Carbon; 18) Apparent Thermal Conductivity of Multilayer Insulation; 19) Optimizing Misch-Metal Compositions in Metal Hydride Anodes; 20) Device for Sampling Surface Contamination; 21) Probabilistic Failure Assessment for Fatigue; 22) Probabilistic Fatigue and Flaw-Propagation Analysis; 23) Windows Program for Driving the TDU-850 Printer; 24) Subband/Transform MATLAB Functions for Processing Images; 25) Computing Equilibrium Chemical Compositions; 26) Program Processes Thermocouple Readings; 27) ICAN-Second-Generation Integrated Composite Analyzer; 28) Integrated Composite Analyzer with Damping Capabilities; 29) Computing Efficiency of Transfer of Microwave Power; 30) Program Calculates Power Demands of Electronic Designs; 31) Cost-Estimation Program; 32) Program Estimates Areas Required by Electronic Designs; 33) Program to Balance Mapped Turbopump Assemblies; 34) BiblioTech; 35) Controlling Mirror Tilt With a Bimorph Actuator; 36) Burst-Disk Device Simulates Effect of Pyrotechnic Device; 37) Bearing-Mounting Concept Accommodates Thermal Expansion; 38) Parallel-Plate Acoustic Absorbers for Hot Environments; 39) Adjustable-Length Strut Withstands Large Cyclic Loads; 40) Tool Indicates Contact Angles in Bearing Raceways; 41) Gravity Slides With Magnetic Braking; 42) High-Torque, Lightweight, Pneumatically Driven Wrench for Small Spaces; 43) Device for Testing Compatibility of an O-Ring; 44) Magnetic Heat Pump Containing Flow Diverters; 45) Variable-Tilt Helicopter Rotor Mast; 46) "Beach-Ball" Robotic Rovers; 47) Apparatus Would Measure Temperatures of Ball Bearings; 48) Flexible Borescope for Inspecting Ducts; 49) Texturing Copper To Reduce Secondary Emission of Electrons; 50) Automated Laser Cutting in Three Dimensions; 51) Algorithm Helps Monitor Engine Operation; 52) Flexible Revision of Data-Processing Communications; 53) Software for Managing the Use of Land; 54) Thermal Strap Increases Cryocooling Efficiency; 55) Reversible Nut With Engagement Indication; 56) Control Algorithms for Kinematically Redundant Manipulators; 57) Computed Hydrogen-Flow Splits in a Rocket Engine; 58) Pressure and Thermal Modeling of Rocket Launches; 59) Field of View of a Spacecraft Antenna: Analysis and Software; 60) Digital Controller for Laser-Beam-Steering Subsystem; 61) More About Beam-Steering Subsystem for Laser Communication; 62) Digital Controller for Laser-Beam-Steering Subsystem: Part 2; 63) Interface Circuit Board for Space-Shuttle Communications; 64) Automated Planning of Spacecraft Telecommunications; 65) Artifacts of Spectral Analysis of Instrument Readings; 66) Neural-Network Controller for Vibration Suppression; 67) Adaptive Finite-Element Computation in Fracture Mechanics; 68) Attitude Control for the Cassini Spacecraft; 69) Analytical Model for Fluid Dynamics in a Microgravity Environment; 70) Study of Rocket-Engine Joints Bonded by NVCU/NARloy-Z; 71) Improved Silicon Nitride for Advanced Heat Engines; 72) Parameters for Welding Aluminum/Lithium Alloys; 73) Lightweight Composite Intertank Structure; 74) Foil Patches Seal Small Vacuum Leaks; 75) Data Base on Cables and Connectors; 76) Effect of Clock Mode on Radiation Hardnessf an ADC; and 77) Fault-Tolerant Control for a Robotic Inspection System.

Source record↗
NASA NTRS1987

Stressed photoconductive detector for far-infrared space applications

An optimized leaf-spring apparatus for applying uniaxial stress to a Ge:Ga far-IR photoconductor has been designed and tested. This design has significant advantages for space applications which require high quantum efficiency and stable operation over long periods of time. The important features include adequate spring deflection with relatively small overall size, torque-free stress, easy measurement of applied stress, and a detector configuration with high responsivity. One-dimensional arrays of stressed photoconductors can be constructed using this design. A peak responsivity of 38 A/W is achieved in a detector with a cutoff wavelength of 200 microns, which was operated at a temperature of 2.0 K and a bias voltage equal to one-half of the breakdown voltage.

Wang, J.-Q.↗
NASA NTRS1987

An overview of controls research on the NASA Langley Research Center grid

The NASA Langley Research Center has assembled a flexible grid on which control systems research can be accomplished on a two-dimensional structure that has many physically distributed sensors and actuators. The grid is a rectangular planar structure that is suspended by two cables attached to one edge so that out of plane vibrations are normal to gravity. There are six torque wheel actuators mounted to it so that torque is produced in the grid plane. Also, there are six rate gyros mounted to sense angular motion in the grid plane and eight accelerometers that measure linear acceleration normal to the grid plane. All components can be relocated to meet specific control system test requirements. Digital, analog, and hybrid control systems capability is provided in the apparatus. To date, research on this grid has been conducted in the areas of system and parameter identification, model estimation, distributed modal control, hierarchical adaptive control, and advanced redundancy management algorithms. The presentation overviews each technique and presents the most significant results generated for each area.

Montgomery, Raymond C.↗
NASA NTRS2004

NASA Tech Briefs, September 2004

Topics covered include: Brazing SiC/SiC Composites to Metals; Composite-Material Tanks with Chemically Resistant Liners; Thermally Conductive Metal-Tube/Carbon-Composite Joints; Improved BN Coatings on SiC Fibers in SiC Matrices; Iterative Demodulation and Decoding of Non-Square QAM; Measuring Radiation Patterns of Reconfigurable Patch Antennas on Wafers; Low-Cutoff, High-Pass Digital Filtering of Neural Signals; Further Improvement in 3DGRAPE; Ground Support Software for Spaceborne Instrumentation; MER SPICE Interface; Simulating Operation of a Planetary Rover; Analyzing Contents of a Computer Cache; Discrepancy Reporting Management System; Silicone-Rubber Microvalves Actuated by Paraffin; Hydraulic Apparatus for Mechanical Testing of Nuts; Heat Control via Torque Control in Friction Stir Welding; Manufacturing High-Quality Carbon Nanotubes at Lower Cost; Setup for Visual Observation of Carbon-Nanotube Arc Process; Solution Preserves Nucleic Acids in Body-Fluid Specimens; Oligodeoxynucleotide Probes for Detecting Intact Cells; Microwave-Spectral Signatures Would Reveal Concealed Objects; Digital Averaging Phasemeter for Heterodyne Interferometry; Optoelectronic Instrument Monitors pH in a Culture Medium; Imaging of gamma-Irradiated Regions of a Crystal; Photodiode-Based, Passive Ultraviolet Dosimeters; Discrete Wavelength-Locked External Cavity Laser; Flexible Shields for Protecting Spacecraft Against Debris; Part 2 of a Computational Study of a Drop-Laden Mixing Layer; Controllable Curved Mirrors Made from Single-Layer EAP Films; and Demonstration of a Pyrotechnic Bolt-Retractor System.

Source record↗