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Technical Paper
1940-01-01
C. G. Williams, H. Ludicke
CASE-HARDENING is a satisfactory means of reducing crankpin wear with “lead-bronze” or copper-lead bearings, the authors reveal. They report the results of tests to determine the relative wearing properties of various crankshaft materials when running against a typical copper-lead alloy bearing at a temperature of 212 F. In general and contrary to what was observed with the softer crankpin materials, bearing wear occurred more rapidly than crankpin wear, they divulge, this result being due largely to high initial wear of the bearings during the early part of the tests. Variations in composition-percentage of lead and tin, and hardness-of the copper-lead bearings did not have a marked effect on the wear obtained, they find. The crankpin materials tested, which were all ground-finished, are specified as: a nickel-chrome steel, heat-treated; a nickel steel, not heat-treated; a nickel-chrome-molybdenum steel, both heat-treated and not heat-treated; a carbon steel, both heat-treated and not heat-treated; three cast materials; three chromium-plated materials (two not ground); three other surface-hardening treatments, namely, carburizing, a proprietary hardening process, and nitriding.
Technical Paper
1940-01-01
S. M. McKee
Technical Paper
1940-01-01
A. E. Traver, C. E. Habermann
Standard
1939-12-04
This specification covers an aircraft quality, low alloy steel in the form of sheet, strip, and plate. These products have been used typically for heat treated parts and structures that may require welding during fabrication, but usage is not limited to such applications. It may be through-hardened to a minimum tensile strength of 180 ksi (1241 MPa) in sections 0.125 inch (3.18 mm) and under in nominal thickness and proportionately lower strength in heavier section thicknesses.
Magazine
1939-10-01
Magazine
1939-09-01
Magazine
1939-02-01
Technical Paper
1939-01-01
L. A. WENDT, T. B. RENDEL
Technical Paper
1939-01-01
C. G. A. Rosen
Technical Paper
1939-01-01
EDWARD F. HARRISON
Technical Paper
1939-01-01
Ernest E. Wilson, Paul Huber
THE authors introduce their paper by outlining the various sources of noise existing in the motor car, together with some of the suppression means. Noise measurement, test methods, and the mechanism of the transmission of forces generated by the contact between the tire and the road to the body and frame are discussed. The authors state that, since these forces produce motion and deflection of the body, they are responsible for the road noise, and conclude that the proper approach to a method for suppressing road noise is through the structural design of the vehicle. They suggest, in the main, the localizing of stress to stress members, the raising of the resonant frequencies of the structure, the detuning of the suspension system, the body, and the frame, together with some isolation at selected points.
Technical Paper
1939-01-01
B. A. Yates
THE importance of the material of the piston ring has too long been relegated to the background as compared with such design factors as ring proportions, ring loadings, circularity, point pressure, and so on; therefore, this paper concentrates on the material factors - such as composition, structure, and surface finish - which should go into the modern piston ring. The causes of piston-ring wear are analyzed and classified under three headings - abrasion, corrosion, and erosion. Various types of coating materials, both metallic and non-metallic, employed to reduce the severity of scuffing or scoring, are considered. Test results are revealed that indicate that superficial coatings reduce piston-ring wear from scuffing and erosion, and that a very thin coating of tin was more effective than other types of metallic and non-metallic coatings.
Technical Paper
1939-01-01
J. B. Johnson
MAGNAFLUX testing has become an important adjunct in connection with the inspection of aircraft parts fabricated from magnetic materials. The method is very sensitive and may indicate not only defects which seriously weaken the part, but also non-injurious imperfections. The author has classified the several defects indicated by magnaflux which have been found in the routine inspection and examination of a large number of parts which have been in service in engines, airplanes, and accessories operated by the U. S. Army Air Corps.
Technical Paper
1939-01-01
Edmund T. Allen
THE organization, training, attitude, and esprit of the crew are all-important for successful flight-testing of large aircraft, Mr. Allen shows. These problems, he explains, are similar to those involved in the functioning of a military unit or of a city government. Choosing the required personnel of from 3 to 10 men fitted to their various duties, training and coordinating them, and building up an efficient unit for collecting accurate flight-test data under conditions of hazardous operation devolves upon the chief test pilot. Since flight-testing involves continuously extending the range of investigation of flight characteristics toward margins of safety, the principle of least hazard has been developed to guide all flight planning and all test operation. This least-hazard principle guides the testing of structure and functional systems through the initial flights, stability tests, performance tests, and flying qualities determination. The high cost per minute of test flying is another factor of extreme importance brought out by Mr.
Technical Paper
1939-01-01
Paul S. Lane
PISTON-RING irons are not the “best-wearing” irons, contends Mr. Lane in his discussion of bore wear from the standpoint of the materials commonly used for high-speed automotive diesel and aircraft-engine cylinders, liners, and rings. Measured on a weight-loss basis under direct comparison with other conventional iron structures, piston-ring irons normally give relatively high weight-loss figures. But piston-ring irons do have the significant and desirable faculty of wearing away with very little tendency to accumulate wear products on their rubbing surface. In fact, this ability is probably of equal or greater importance than actual low weight loss. In his paper Mr. Lane reports the results of several years of laboratory wear-testing research, correlated in many instances with actual service experience, from the viewpoints of hardness, structure, and chemical composition. Variations in the structure and wear of automotive cylinder castings are illustrated along with the tendency of different type cast irons toward scuffing and scoring, and the cause or reasoning for such tendencies, from the standpoint of the nature of the metal structure, is pointed out.
Technical Paper
1939-01-01
J. F. Winchester, J. J. Powelson
Technical Paper
1939-01-01
Sidney J. Williams
Technical Paper
1939-01-01
A. O. Willey
Technical Paper
1939-01-01
F. L. Miller
Technical Paper
1939-01-01
Alexander v. Philippovich
Technical Paper
1939-01-01
T. R. STENBERG, C. N. MENZ
Technical Paper
1939-01-01
Lawrence J. Grunder
Magazine
1938-11-01
Magazine
1938-06-01
Magazine
1938-02-01
Viewing 22231 to 22260 of 22517

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