| Bearing Survivability and Friction Determination for Fuze Decoupling Applications |
Sep 2012 |
18 pages |
| Authors:
E Marshall; M Pica; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL NJ MUNITIONS ENGINEERING TECHNOLOGY CENTER
|
 | The objective of this experiment is to find bearings that are suitable for de-spinning a fuze from a projectile body. Bearings must be able to survive both gun launch loads and high spin rates in this application. Three pairs of bearings are allowed to de-spin from approximately 250 Hz and then shot in a 155-mm air gun to simulate these loads. Overall bearing survivability and changes in friction (as measured ... |
|
| Health Assessment and Fault Classification of Roller Element Bearings |
Jul 2012 |
24 pages |
| Authors:
Andrew J Bayba; David N Siegel; Kwok Tom; Derwin Washington; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Feature extraction, health assessment, and fault classification algorithms were evaluated for ball bearings with three different fault types and multiple levels of damage. Data was analyzed for five healthy bearings, and seeded fault bearings with five levels of damage for each fault type (ball fault, inner race fault, and outer race fault). A variety of fault analysis techniques were used to calculate properties (features) of the data sets, which were ... |
|
| Seeded Fault Bearing Experiments: Methodology and Data Acquisition |
JUN 2011 |
40 pages |
| Authors:
Andrew J. Bayba; Derwin Washington; Kwok Tom; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| As part of the U.S. Army Research Laboratory (ARL) Prognostics and Diagnostics (P&D) Program, a series of experiments were performed to study defects in ball bearings. The P&D Program objective is to develop and implement algorithms that detect and classify faults in U.S. Army systems, providing information on the state of health and predictions of remaining life. Due to the substantial use of bearings in Army assets and the significant ... |
|
| Damage Assessment of a Small Spherical Projectile Impacting on a Glass Shield |
Jan-2009 |
10 pages |
| Authors:
Jian H Yu; Peter G Dehmer; James M Sands; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| A high-speed photographic method was set up to track a small projectile in flight and capture its subsequent impact on a glass shield. A 1.0-mm-diameter steel ball bearing was launched from a compressed helium gas gun. The flight of the projectile and the impact event were captured with high-speed cameras. The glass shield showed visible damage at an impact speed of more than 205 m/s. |
|
| Magnetron Sputtered Pulsed Laser Deposition Scale Up |
14 AUG 2003 |
85 pages |
| Authors:
Samuel J. Laube; Jeffery J. Heyob; INFOSCRIBE TECHNOLOGIES LTD (ISTL) BEAVERCREEK OH
|
| The objective was primarily to utilize the newly developed Air Force super-hard coating process technologies in practical applications, such as turbine engine rotor components, precision shafts and ball bearings, and bearing races. This would give the Air Force the capability of practically coating real precision mechanical parts with solid lubricant films of the highest toughness. These films would be of the highest hardness and the most resilient to damage, extending ... |
|
| Tribology of Composite Au-MoS2 Films at Varying Contact Stresses |
01 JUN 2003 |
20 pages |
| Authors:
J. R. Lince; AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS
|
| Solid-lubricant coatings for sliding electrical contact applications like slip-ring assemblies have very different requirements from typical applications like ball bearings and cutting tools: they have significantly lower contact stresses and sliding speeds. We are optimizing the performance of sputter-deposited nanocomposite Au-MoS2 films for such low con tact stress applications. Higher contact stress pin-on-disk tests (S(sub m) = 730 MPa) showed that low Au-MoS2 films (i.e., 22 to 38 at% Au) ... |
|
| Closed Field Unbalanced Magnetron Sputtering--Environmentally Safe Corrosion and Wear Coatings for Fasteners |
FEB 2002 |
35 pages |
| Authors:
Larry L. Fehrenbacher; TECHNOLOGY ASSESSMENT AND TRANSFER INC ANNAPOLIS MD
|
| The Wear Sciences Coating Group of TA&T, Inc. under DARPA sponsorship has developed a new thin film coating method process aircraft piece parts such as fasteners and bearing balls. The objective of this technology development, demonstration, and commercialization program was to replace cadmium-plated parts with an environmentally friendly, low-cost multilayer and/or graded coating based on the Cr/CrxN system. This same material system was also evaluated as an improved bearing coating ... |
|
| An Approach to Predicting the Threshold of Damage to an Angular Contact Bearing During Truncation |
01 MAR 2001 |
18 pages |
| Authors:
P. P. Frantz; A. R. Leveille; AEROSPACE CORP EL SEGUNDO CA LAB OPERATIONS
|
| A simple, approximate expression is developed, relating the mean stress with the fraction truncated at the contact between a ball and raceway of a loaded angular contact ball bearing. This expression is to serve as a rule-of- thumb for the bearing analyst to predict the likelihood of bearing damage due to truncation. The contact is said to be truncated when the contact area reaches beyond the edge of the raceway. ... |
|
| Ball Lock Mechanism |
15 DEC 1998 |
12 pages |
| Authors:
DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A ball lock mechanism has a shaft with an annular groove formed therearound. A first sleeve fitted on the shaft defines at least one channel between the first sleeve and the shaft. An opening facing away from the shaft is formed at the end of each channel. Ball bearings fill each channel so that, when the channels and annular groove are misaligned, one of the bearings extends partially through each ... |
|
| Investigation of Bearing Technology |
26 AUG 1998 |
70 pages |
| Authors:
Walter J. Maciag; POWDERED MATERIAL APPLICATIONS INC BAY VILLAGE OH
|
| This report records and documents Laboratory and Field Test data that demonstrates the superiority of new universal joints that utilize a unique, innovative technological concept. These "GC U-Joint's were tested on the Propeller Shafts of the HMMWV in direct comparison with Standard universal joints. They are interchangeable. The new bearings, named "Geometrically Contoured (GC) Bearings" for their design configurations, are made from powdered metal materials. They ... |
|
| Effects of Varying Ball Bearing Cleaning Processes on Lubricant Life |
20 JAN 98 |
26 pages |
| Authors:
S. V. Didziulis; J. L. Childs; D. J. Carre; AEROSPACE CORP EL SEGUNDO CA ENGINEERING AND TECHNOLOGY GROUP
|
| The processes used to clean ball bearings and other components in precision spacecraft mechanisms have undergone significant changes to eliminate the use of ozone depleting chemicals, such as Freon TF. This study was part of a larger NASA-funded program to assess the impact of the elimination of ozone- depleting chemicals on lubricant performance in space mechanisms previously qualified for 5 to 10 year lifetimes. The document reports the results of ... |
|
| Tribology in the Space Environment |
15 OCT 1997 |
24 pages |
| Authors:
P. D. Fleischauer; AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS
|
| The environments of spacecraft-be they launch vehicles, orbiting satellites, or exploration vehicles (the moon or other planets)-are definitely extreme. While apparatus can be forced to operate in extreme heat or cold, in radiation environments, or under severe conditions of load, speed, and direction of motion, the major condition with which space tribology must be concerned is the vacuum environment, i.e., the absence of atmospheric gases that often provide protective coatings ... |
|
| Automated Silicon Nitride Bearing Ball Inspection Station |
FEB 96 |
13 pages |
| Authors:
David E. Thomas; QUATRO CORP ALBUQUERQUE NM
|
| Contract Number DAAH0l-94-C-R285, Quatro Corporation has developed a fully-functional, automated silicon nitride Bearing Ball Inspection Station which utilizes Resonant Inspection (Resonant Inspection) to determine if the balls are flawed or acceptable. The Bearing Ball Inspection Station was demonstrated at the Norton Advanced Ceramics facility in East Granby, Connecticut in October of 1995. The station was successful in finding flaws in several sizes of silicon nitride bearing balls, although more work ... |
|
| A Comparison of Digital and Analogue Vibration Analysis Techniques for the Detection of Ball Bearing Faults |
JAN 96 |
|
| Authors:
Mark Shilo; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)
|
 | 'Envelope Detection' is a technique of using vibration analysis for detecting the presence of surface defect faults in ball bearings and rolling element bearings. Envelope detection has been demonstrated to be capable of detecting ball bearing faults where traditional vibration analysis techniques have been unsuccessful. There are many tools commercially available for bearing fault detection, some of which use the technique of envelope detection. Personal computers (PCs) are used extensively ... |
|
| Correlation of Experimental and Finite Element Modal Analysis of the Phalanx M61A1 Close-in Weapon System |
DEC 95 |
134 pages |
| Authors:
Carlos S. Guzman; John C. Gaffe; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The M6 1 Al gatling gun is the principal component of the PHALANX close-In Weapons System (CIWS), which provides U.S. Navy surface ships with a final defense against anti-ship cruise missiles. The objectives of this study are to provide an experimental set of modal parameters and to validate a new finite-element model (FEM) of the gun. Swept sine frequency response measurements on an actual PHALANX gun were conducted in the ... |
|
| Computerized Design and Life Prediction - Bearings |
20 APR 95 |
82 pages |
| Authors:
Crawford Meeks; Elias Polendo; AVCON ADVANCED CONTROLS TECHNOLOGY INC AGOURA HILLS CA
|
| This report documents the computer study of bearing cage designs. The proposed cage designs possessed unsymmetrical geometry which differed considerably from conventional cage design. The ball bearing dynamics software, BABERDYN2, was modified to enable the analysis of this new geometry. Subsequently, an optimization study of the ball-to-pocket and land riding clearances was performed. This report contains the result of the study. |
|
| Ceramic Bearing Development. Volume 4. Tribochemical Finishing of Silicon Nitride |
MAR 95 |
115 pages |
| Authors:
S. R. Hah; Traugott E. Fischer; Charles Burk; CERBEC INC EAST GRANBY CT
|
| Tribochemical finishing of silicon nitride was developed by the Tribology Research Group at the Stevens Institute of technology. The finishing process produces ultrasmooth surfaces without mechanical defects. Over 40 chemical solutions such as acids, bases, salts, inorganic and organic oxidizers were tested. Distilled water shows high volume removal rates but some solid wear debris are produced by surface fracture. Hydrogen peroxide, at 3% or higher concentrations, produces high volume removal ... |
|
| Ceramic Bearing Development. Volume 3. Development of a Thermal Proof Test for Silicon Nitride Balls |
MAR 95 |
103 pages |
| Authors:
Leon Chuck; Kevin Hallinan; Charles Burk; CERBEC INC EAST GRANBY CT
|
| The Major objective of the Development of a Thermal Proof Test for Silicon Nitride Balls was to improve hybrid bearing reliability by the elimination of critical size flaws that cause early failures. The two main tasks in this effort were the demonstration of a thermal proof test method, and the fatigue life testing of thermal proof tested balls. A thermal proof test based on fracture mechanics was developed. A Weibull ... |
|
| Composite Coupling for Towed Arrays. |
14 FEB 1995 |
|
| Authors:
Thomas R. Stottlemyer; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A coupling for joining sections of an underwater towed acoustical array includes male and female couplers. The male coupler has an annular end portion with an axial bore that receives a first towed array section and a first connector and an annular body integral with and extending coaxially from the annular end portion. An outer groove is disposed around an outer circumference of the annular body. The female coupler has ... |
|
| Improved Hybrid Bearings |
DEC 94 |
129 pages |
| Authors:
Michael M. Dezzani; Philip K. Pearson; TORRINGTON CO CT
|
| Nitriding technology was determined to significantly enhance the performance of steel bearing rings coupled with silicon nitride balls. NBD-200 silicon nitride was tested in two different sized full scale bearing tests with two nitrided steel ring materials, M50 and M50 NiL. Test bearing sizes were 35mm bore radial bearings and 40mm bore thrust bearings. Results showed truly superior rolling contact fatigue life under conditions of thin film and contaminated lubricant. ... |
|
| Effect of Variation of the Angle Between Joined Armor Plates on Ballistic Shock Attenuation |
JUN 94 |
72 pages |
| Authors:
Ricky L. Grote; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Ballistic shock has been recognized by the vulnerability community as a damage-producing mechanism worthy of investigation. A simple straight line analysis method has been proposed and is being pursued. One factor not considered to this point is the effect of angle variation between welded plates on shock attenuation. The object of this research effort was to determine if such an effect exists, and, if so, a determination of the effect ... |
|
| Computer Graphics for Bearing Dynamic Analysis |
30 DEC 91 |
40 pages |
| Authors:
James D. Moore; Doug A. Clemons; SRS TECHNOLOGIES HUNTSVILLE AL
|
| The enormous amount of data produced by computer codes used by the aerospace industry to design and evaluate high speed rolling element bearings makes it difficult and time consuming to synthesize and evaluate analysis results. The objective of this research effort was to determine if computer graphics and animation techniques can be used to develop software tools for postprocessing dynamic analysis results and presenting the results in a clear concise ... |
|
| Animated Computer Graphics Modeling of Rolling Bearing Dynamics |
18 DEC 91 |
29 pages |
| Authors:
Pradeep K. Gupta; GUPTA (PRADEEP K) CLIFTON PARK NY
|
| A two dimensional animated graphics model to simulate dynamic motions of the balls and cage, in a plane normal to the bearing axis, in an angular contact ball bearing is developed. The graphics modeling is based on the primitives available under the Programmers Hierarchical Interactive Graphics System (PHIGS), which is now an international standard and it is supported on a wide range of computer systems. Appropriate transformations to produce the ... |
|
| Automating Low-Volume Assembly. |
MAY 1991 |
|
| Authors:
M. Hamilton
|
|
| Big Guns for Large-Scale Soldering. |
MAY 1991 |
|
| Authors:
A. F. Benson
|
|
| Automation in the Electronics Industry. |
MAY 1991 |
|
| Authors:
L. K. Schuch
|
|
| How SPC (Statistical Process Control) Works in Contract Shop. |
SEP 1990 |
|
| Authors:
B. Eade; K. Gettelman
|
| Now, zero defects is the goal of leading domestic manufacturers, and one of the tools most often used in pursuit of that goal is statistical process control (SPC). Once considered suitable only for manufacturers involved in large-scale production, SPC has found its way into the contract supplier shops. It is not unusual to see SPC used even in small shops within this industry. (Copyright 1990 by Modern Machine Shop). |
|
| The Soviet Union: Making the Change from a Command to a Demand Economy. |
SEP 1990 |
|
| Authors:
R. G. Kline
|
| Obviously, changes are occurring, but what does this all mean to American manufacturers of industrial products? The answer is, opportunity, and the possibility of forming long-term relationships that can result in profits. (Copyright 1990 by Modern Machine Shop). |
|
| Wear Measurement of Ceramic Bearings in Gas Turbines |
MAR 90 |
58 pages |
| Authors:
A. J. Armini; S. N. Bunker; IMPLANT SCIENCES CORP DANVERS MA
|
| The objective of this program was to determine the feasibility of measuring ceramic bearing wear in real time. The method chosen is to selectively introduce a radioactive tag into the surface of a ceramic part and to measure the wear amount by monitoring the strength of the tagging activity as the test progresses. Although this method has been used for many years in the automobile and heavy machinery industries, it ... |
|
| Ion Implantation of Ceramic Bearings. |
JUN 1989 |
34 pages |
| Authors:
A. J. Armini; S. N. Bunker; IMPLANT SCIENCES CORP DANVERS MA
|
| This report explores the use of ion implantation techniques to form solid lubricating surfaces on all ceramic (silicon nitride) and hybrid ball bearings. Techniques were developed to implant and/or cost silicon nitride and 52100 bearing steel with MoS2, Boron, and Tin ion beams. A friction/wear tester was also developed to evaluate these coatings in both air and dry nitrogen atmospheres. Friction test results have yielded durable films on both silicon ... |
|
| Shock and Vibration Symposium (59th) Held in Albuquerque, New Mexico on 18-20 October 1988. Volume 3 |
OCT 88 |
332 pages |
| Authors:
SANDIA NATIONAL LABS ALBUQUERQUE NM
|
| Partial contents: Machinery vibration -- Mechanical signature analysis, High frequency vibration analysis for rotating equipment and piping systems, Diagnosing problems in modern 2-pole induction motors, Absolute ball bearing wear measurements from SSME turbopump dynamic signals; Spectral normalizing, and Kinematics of a flexible length redundant robotic arm; Vibration control -- Optimization of a five-parameter nonlinear shock mount, Active damping design of flexible structures based on non collocated sensor- actuator velocity feedback, ... |
|
| EPIC-2 Predicted Shock Environments in Rolled Homogeneous Armor for Nonperforating Ballistic Impact |
JAN 88 |
|
| Authors:
Ennis F. Quigley; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A series of controlled experiments were conducted to characterize the ballistic shock environment produced in rolled homogeneous armor by nonperforating ballistic impact. Displacements, velocities, accelerations and strains were measured at various locations on the back of 38 and 70 mm thick, 914 mm x 914 mm plates impacted by ball bearings and small caliber projectiles (30 caliber to 20 mm). Projectile impact velocities ranged from 335 m/s to 1508 m/s. ... |
|
| Computer Simulation of Ball Bearing Dynamics and Correlation with Test Measurement on Ball Separator Motions |
OCT 86 |
|
| Authors:
C. R. Meeks; HUGHES AIRCRAFT CO EL SEGUNDO CA ELECTRO-OPTICAL AND DATA SYSTEMS GROUP
|
| A high-speed computer program, SEPDYN, simulating all of the kinematics and dynamic motions of ball bearings was used to analyze and predict ball separator motions of an oil-lubricated 100-mm-bore ball bearing. The predicted ball separator motions were compared with actual test data on separator motions in this bearing, and remarkable agreement was found between predictions and measurements. All conditions tested showed that the ball separator whirls at approximately the ball ... |
|
| Design and Calculation of High Speed Engine Bearings, |
FEB 1986 |
|
| Authors:
H. J. Koeber; Georg Schaefer; ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE)
|
| New aspects in design and calculation of high speed ball and roller bearings are discussed in as much as they effect bearing performance in the speed range of DxN = 3,000,000/min and beyond. For roller bearings the guide flange to roller end configuration as well as roller excursion while the cage pocket are linked to the phenomena of skewing and skidding. The need for under-race-lubrication in small diameter engine bearings ... |
|
| Surface Creep of Mineral Oil on Inner Ring of Momentum Wheel Bearing |
19 AUG 85 |
|
| Authors:
P. D. Fleischauer; H. D. Marten; AEROSPACE CORP EL SEGUNDO CA CHEMISTRY AND PHYSICS LAB
|
| Lubricant distribution on the inner ring of an inner-ring rotating bearing may depend on the creep of oil from the bearing raceway up onto the land and subsequent transfer to retainer surfaces. To study creep patterns for a bearing spinning at speeds up to 9000 rpm, a fixture was built so that the motion of the oil could be observed and photographed using ultraviolet stimulated luminescence of the oil. Oil ... |
|
| Elastic Bearing |
16 AUG 85 |
|
| Authors:
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
| The common ball bearings and sliding bearings are well known to people since they are widely employed in modern industries such as trains, automobiles, ships, aircraft, machine tools, instruments, etc. They have also been used in many household appliances or equipment such as fan, sewing machine, bicycle, clock, etc. The elastic bearings are rather unfamiliar to people. This report describes the features of elastic bearings and compares them to sliding ... |
|
| Perfluoropolyalkylether Oil Degradation: Inference of FeF3 Formation on Steel Surfaces under Boundary Conditions |
01 AUG 85 |
24 pages |
| Authors:
D. J. Carre; AEROSPACE CORP EL SEGUNDO CA CHEMISTRY AND PHYSICS LAB
|
| The formation of iron fluoride (FeF3) through the interaction of Kaytox 143AB perfluoropolyalkylether (PFPE) oil with steel surfaces was investigated under boundary lubrication conditions. Ball-bearing rolling action was simulated by a specially designed wear-test apparatus that incorporated noncoaxial wear members to give a skid/roll ratio of approx. 0.16. The contact stress was 830,000,000 sq m (approx. 120,000 psi), and the speed was 1750 rpm. Under these conditions, FeF3 formation on ... |
|
| A Flight Management Algorithm and Guidance for Fuel-conservative Descents in a Time-based Metered Air traffic Environment; Development and Flight Test Results. |
DEC 1984 |
|
| Authors:
C. E. Knox; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
|
| A simple airborne flight management descent algorithms designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and ... |
|
| An Application of the Principles of War to the Schweinfurt Raids on 17 August 1943 and 14 October 1943 |
APR 1984 |
65 pages |
| Authors:
T. J. Griffith; AIR COMMAND AND STAFF COLL MAXWELL AFB AL
|
| Provides a historical look at the use of daylight precision bombing by American bombers against the ball-bearing factories at Schweinfurt, Germany, on 17 August 1943 and 14 October 1943. The principles of war from AFM 1-1, Basic Aerospace Doctrine of the United States Air Force, are used to analyze the strengths and weaknesses of the American and German efforts during these operations. (Author) |
|
| Current Work on High-Grade Space Gyros at Ferranti in the UK, |
JAN 1984 |
|
| Authors:
J. Welburn; FERRANTI PLC EDINBURGH (SCOTLAND)
|
| Certain satellite missions require gyroscopes of very high accuracy for attitude measurement. Formerly, floated rate integrating gyros have been widely used. More recently in the USA, 2-axis DTG's have been used, and agencies are not beginning to consider what type of instrument to use in the future. Whereas most US companies have tended to abandon floated gyros in favour of dry gyros (principally on grounds of manufacturing cost, we suspect) ... |
|
| Engine-Transmission Angular-Contact Ball Thrust Bearing Endurance Tests |
NOV 1983 |
|
| Authors:
B. B. Baber; SOUTHWEST RESEARCH INST SAN ANTONIO TX
|
| Six bearings were endurance tested in pairs in a machine utilizing back-to-back loading of the bearing pairs. Each pair of bearings were run using a predetermined speed and load test schedule for 1,000 hours or failure, whichever occurred first. A description of the test program and the results obtained are described. |
|
| Millimeter Wave Dielectric Waveguide Rotary Joint. |
25 OCT 1983 |
|
| Authors:
Donald D. Paolino; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A dielectric waveguide is used as a connecting medium in a rotary joint transmitting waveguide energy in the 3 mm region. The dielectric waveguide is fastened within a ball bearing race to provide relative motion between the gimballed and stationary waveguide structure. Launch horns are used to enhance transmission through said dielectric waveguide. |
|
| Optical Fiber Lightguide Sensing for Gimbal Pickoffs |
JUN 1983 |
|
| Authors:
Aubrey Rodgers; ARMY MISSILE COMMAND REDSTONE ARSENAL AL GUIDANCE AND CONTROL DIRECTORATE
|
| The application of optical fiber lightguides in gimbal pickoffs is under study by the U.S. Army Missile Command. Laser diodes or light-emitting diodes, optical fibers, and solid-state light detectors can save space and weight in inertial-guidance systems for missiles and projectiles. Because they are non-contacting and have no moving parts, optical components are free of friction, gimbal-wiring, slip ring torques, potentiometer-wiper lift-off during flight, and noise. The sensors and optical ... |
|
| DSCS (Defense Satellite Communications System) II 9444 Despin Pointing Anomaly |
01 APR 1983 |
89 pages |
| Authors:
P. H. Fowler; TRW DEFENSE AND SPACE SYSTEMS GROUP REDONDO BEACH CA
|
| Presents the results of an investigation of minor intermittent pointing wander in 9444 and other DSCS II satellites. Ascribes the effect to sticking in the preload mechanism, and shows numerical reasons for this conclusion. (Author) |
|
| An SEM Analysis of Bearing Failure Due to Electrical Arcing (Analyse par Microscopie Electronique a Balayage de l'Endommagement d'un Roulement a Billes a la Suite de Decharges Electriques Internes) |
JAN 1983 |
16 pages |
| Authors:
W. Wiebe; D. D. Morphy; NATIONAL AERONAUTICAL ESTABLISHMENT OTTAWA (ONTARIO)
|
| Failure of a cam clutch after sofme 2,000 hours of operation was found to be due to bearing failure. When examined in the scanning electron microscope, evidence of molten metal in the form of craters or pools, and of minute globules of metal was found on the balls and races of the bearings. This suggested that electrical arcing between the balls and the races had occurred, and this was considered ... |
|
| Wear Debris Analysis of Grease Lubricated Ball Bearings |
12 APR 1982 |
|
| Authors:
A. S. Maciejewski; J. W. Rosenlieb; NAVAL AIR ENGINEERING CENTER LAKEHURST NJ SUPPORT EQUIPMENT ENGINEERING DEPT
|
| An investigation was conducted to experimentally determine the wear surface condition of grease-lubricated ball bearings, by monitoring the wear debris retained in the grease. Testing of six bearings was performed on endurance test machines with grease sample removal. Visual and scanning electron microscope examinations of the bearing surfaces were performed per an established schedule by SKF. Respective grease samples were treated, analyzed, and correlated by NAVAIRENGCEN. A total of four ... |
|
| Turbocharging of Small Internal Combustion Engine as a Means of Improving Engine/Application System Fuel Economy-Further Turbocharger Improvements |
APR 1982 |
|
| Authors:
John R. Arvin; AERODYNE DALLAS TX
|
| Improvements to a small diesel engine turbocharger were made based on data gathered during a previous Army contract. The improved turbocharger was fabricated and tested on a small, four cylinder, 239 CID diesel engine. Engine dynamometer test data revealed a 2 to 9 percent reduction in fuel consumption at all points over the operating envelope. A turbocharger was operated for 1011 hours at speeds between 70000 and 78000 rpm without ... |
|
| Impact Response Characteristics of Polymeric Materials |
NOV 1981 |
98 pages |
| Authors:
William B. Hillig; GENERAL ELECTRIC CORPORATE RESEARCH ANDDEVELOPMENT SCHENECTADY NY
|
| This report describes the concluding work on a series of studies concerned with determining, understanding, and trying to predict the behavior of polymethylmethacrylate (PMMA) and polycarbonate (PC) under impact. In the present work the impact velocity was extended to 2.1, 125, and 220 m/s using a 4.5 mm steel ball as the projectile. Because of dispersion effects the pulse detected using an instrumented Hopkinson impact bar was markedly distorted. A ... |
|
| Manual on the Fatigue of Structures. II. Causes and Prevention of Damage. 7. Mechanical Surface Damage, |
JUN 1981 |
|
| Authors:
W. G. Barrois; ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT NEUILLY-SUR-SEINE (FRANCE)
|
| The author reviews and compares the processes and practical aspects of the various causes of mechanical damage to the surface of structures, which may lead to fatigue or stress corrosion failure or final rupture under the effect of the loads applied in service. Such damage is the result of heat treatment faults, grinding, wear, rolling fatigue, contact fatigue or fretting, as well as abrasion, solid or liquid particle erosion and ... |
|
| Aerospace Mechanisms Symposium (15th) Held at George C. Marshall Space Flight Center, Alabama on May 14-15, 1996 |
81 |
434 pages |
| Authors:
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HUNTSVILLE AL GEORGE C MARSHALL SPACE FLIGHT CENTER
|
| The proceedings of the 15th Aerospace Mechanisms Symposium held at the George C. Marshall Space Flight Center on May 14-15, 1981, are reported in this NASA Conference Publication. Technological areas covered include aerospace propulsion, aerodynamic devices, and crew safety; space vehicle control; spacecraft deployment, positioning, and pointing; deployable antennas/ reflectors; and large space structures. Devices for payload deployment, payload retention, and crew EVA on the Space Shuttle Orbiter are also ... |
|
Reports by Keyword(s)
BALL BEARINGS
