Hazards in noncritical races.
Hazards in noncritical races, discussing minimum transition time coding of asynchronous sequential switching circuits
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Hazards in noncritical races, discussing minimum transition time coding of asynchronous sequential switching circuits
A Newton-Raphson method of iteration was used in evaluating the radial and axial projection of the distance between the ball center and the outer raceway groove curvature center (V and W). Fatigue life evaluations were made. The similar analysis of a conventional bearing can be directly obtained from the arched bearing analysis by simply letting the amount of arching be zero (g = 0) and not considering equations related to the unloaded half of the outer race. The analysis was applied to a 150-mm angular contact ball bearing. Results for life, contact loads, and angles are shown for a conventional bearing (g = 0) and two arched bearings (g = 0.127 mm (0.005 in.), and 0.254 mm (0.010 in.)). The results indicate that an arched bearing is highly desirable for high speed applications. In particular, for a DN value of 3 million (20,000 rpm) and an applied axial load of 4448 N (1000 lb), an arched bearing shows an improvement in life of 306 percent over that of a conventional bearing. At 4.2 million DN (28,000 rpm), the corresponding improvement is 340 percent. It was also found for low speeds, the arched bearing does not offer the advantages that it does for high speed applications.
Approximately 100 inner race bearings were inspected nondestructively prior to endurance testing. Two of the bearings which failed during testing spalled at the sites of subsurface inclusions previously detected by using magnetic field perturbation. At other sites initially judged to be suspect, subsurface inclusion-nucleated cracking was observed. Inspection records and metallurgical sectioning results are presented and discussed.
Expansion gives rise to eccentricity. Report presents analysis of dynamic effects caused by cracking of inner race of ball bearing in turbopump. Crack manifested itself via increase in vibrations synchronous with rotation and smaller increase at twice frequency of rotation. Analysis conducted to verify these increases were caused solely by crack and to understand implications for future such cracks.
Coating with suitable grease found to inhibit stress-corrosion cracking in bore of inner race of ball-bearing assembly operating in liquid oxygen. Protects bore and its corner radii from corrosion-initiating and -accelerating substances like moisture and contaminants, which enter during assembly. Operating life extended at low cost, and involves very little extra assembly time.
Gradient-tempering process increases fracture toughness and resistance to stress-corrosion cracking of ball-bearing races made of hard, strong steels and subject to high installation stresses and operation in corrosive media. Also used in other applications in which local toughening of high-strength/low-toughness materials required.
Interlocking fine-pitch ribs and grooves formed on otherwise flat mating end faces of housing and outer race of rolling-element bearing to be mounted in housing, according to proposal. Splines bear large torque loads and impose minimal distortion on raceway.
Tests were made on four racing type airfoils in order to determine the high speed characteristics of the wings.
The S.5 is equipped with Napier Lion racing engine, all duralumin floats and has a top speed in excess of 300 M.P.H.
This report presents the author's designs and construction of various seaplanes to raced in the Schneider Cup. The results of tests are presented as well as discussions of various structures like floats and wings.
This report describes the drive system in the Arizona State University Formula Lightning electric race car when it participated in the 1994 Cleveland Electric Formula Classic on 9 July 1994. In addition, the telemetry system used to monitor the car's performance and plans for improving the car's performance are described.
The next Space Race will be in the economic applications from space and science technology. As NASA science and technology has global application; IT is global, economics is global; surely there are great untapped potentials in finding the IT links of commonality among these three. The Economics of IT will continue to depend upon solution providers creating new methods that capitalize on linking information and information centers with the applications community for business and economic functions.. New and innovative IT vendors whose increased efforts to apply evolving technologies and principles that power the e-business revolution are now seeing the business of government being transformed in a similar fashion. NASA will be a prime example of IT transformation. Potential benefits of e-government are identical to the benefits of e-commerce, which start from value derived from capabilities and assets. The capability and asset wealth of NASA technology and data mass scattered through hundreds of archives will one day provide incredible economic benefit across international and corporate boundaries. Yet the ability to economically benefit from bridging the gap between capability to billable service has yet to find it's first major market. Ultimately the role of government, science, and technology linking to the business world will find greater dependence from this increasingly common ground of IT solutions and technologies. Therefore the future role of the IT industry may be as much administrative as technical, ultimately of critical importance furthering the role of science into application.
In 1985, the U.S. Cycling Federation ruled that all racing bikers must wear helmets that meet American National Safety Institute Standards. Existing helmets were hot and heavy. Jim Gentes, president of Giro Sport Design, Inc. turned to Raymond Hicks an aerodynamicist at Ames Research Center for a design for a cool, lightweight helmet. Hicks created an aerodynamic helmet shape using technology from a NACA airfoil section. Air vents make the air flow laminar and reduce drag. Since 1986, Giro helmets have evolved and expanded. One was worn by the 1989 Tour de France winner.
In 1,950 mile Australian race, the General Motors Sunraycer, was powered by space-derived solar cell technology incorporating a number of other aerospace technologies. The 547 lb one seater averaged better than 41 miles per hour and finished 600 miles ahead of the nearest competitor.
Fracture surfaces on a failed bearing race made from 60-Nitinol (60 wt% Ni - 40 wt% Ti) were analyzed. The bearing had experienced excessive localized heat due to an issue during machining that may have resulted in dimensional distortion. However, the classical fracture features that were identified by scanning electron microscopy and the fracture origins coincided with high concentrations of TiC-based contamination. Lessons learned for processing and quality control are discussed. An attempt to use x-ray diffraction to directly measure residual stresses imparted from the required heat treatment is also discussed.
Large, distributed aerospace simulations traditionally have been the domain of customized, closed designs, using statically compiled code based on specialized messaging systems such as DDS and HLA. While this can be suitable for one-off systems or specialized in-house product lines, it increases development costs and lowers extensibility. We propose to use contemporary internet software technology to solve this problem.Our Runtime for Airspace Concept Evaluation (RACE) architecture was born out of the need to rapidly develop and evaluate what-if scenarios that involve the whole National Airspace System (NAS), live NAS data feeds such as the FAA's System Wide Information Management (SWIM) servers, and existing flight simulators. It had to run on off-the-shelf hardware, be open sourced, and support visualization components up to multiple synchronized large screen geo viewers used in situation rooms. Most of all, it had to be extensible - being a viable platform for the development of future simulation components.
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