VOL 1 ~1957~58)
SYSTEMATIC ABSTRACTS
cber trockeae Reibuag bei einigen Almniaiumlegieruagea uad Stiihlen. Dry Friction of Some Aluminum Alloys and Steels. F. Bollenrath and H. Grefkes. A luminium, v. 33, Apr. 1957. P. 234-240. Coefficients of static and cold welding friction depend on materials and conditio&, while those of pure sliding friction are determined by the properties of the material in the surface layers. Calculation of the Contribution Made by Grain-Boundary Sliding to Total Tensile ELongatioa. II. Brunner and N. J. Grant. lnstitule of Metals, Journal, v. 85, Oct. 1956, p. 77-80. Severe stress concentrations occur at the triple points whenever grain-boundary sliding takes place. An equation is derived which permits calculation of the elongation of a tensile specimen caused by sliding along any particular grain boundary. Fatigue of Metals Under Contact Friction. {in Russian) V. S. Ivanova, and I, A. Oding. Izvestiia Akademii Nauk SSSR, Otdelenie Tekhnicheskikh Nauk, no. I, Jan. 1~57, p. 95-102. Decrease in fatigue limit of Cr-Ni-Mo steel during contact f&tion is explained as due to electroerosion from thermoelectric currents produced by changes in contact resistance. This erosion leaves vacancies in the crystal lattice. Fatigue limit can be raised by changing the direction of the thermoelectric current through proper choice of materials or by inducing a counter-cu~ent. TheRelation Between Coefficient of Friction, Conductivity and Static Electrification Iaduced by Frictionin Cellulose AcetateYarns. G. Quintelier, M. WarzBe, and R. Sioncke. Textile Institute, Jourlzal (Proceedings), v. 48, Jan. 1957, p. P26-P39. In order to avoid static troubles in processing, it is desirable that yarns have low coefficients of friction, but even more desirable that they have the largest possible conductivity. r.3. Machine Parts and Machinery Investigation of Cause6 of Low Wheel-t* Rail Adhesion and Possible Methods of Improving It. F. G. Fisher and R. K. Allen. ASME, Transactions, v. 79, Feb. 1957. p. 377-388. Running adhesions in excess of 260/b can be maintained by the application of certain materials to locomotive drivers or to the rail. Design Manual for Roller and Silent Chain Drives. Jackson & Moreland. 95 pp, 1955. Association
2.55
of Roller aad Silent Chain Manufacturers, Detroit. (TJlx17 JI3d Over.) History of the chain drive; comparison of mechanical power drives; description of roller chains and sprockets; design principles; roller chain installation, lubrication, and maintenance: silent chain drives. Use of Rolling Contact Bearings in Low Viscosity Liquid Metal Lubricants. W. Markert, Jr. and K. Mildred Ferguson. LubricatioPt E~g~~eer~~ag, v. 13. Bay 1957~ p. 285-290. Tests with bearings submerged in and lubricated by either liquid NaK, or liquid Na. Mechanism of bearing failure. &ude de la tempCrature en milieu thermique limit6 dans les probl&mes de frottement apoliauts au freinaee. k Siudy of Temperature in a Limited Thermal Medium Applied to Friction Problems in Braking. Tean Odier and Pierre Leutard. Comptes Ren&s, v. 244, Feb. 25, 1957, p. 1141-1;42. A theoretical studv of a formula expressing the increase of the-average temperacure of a rubbing surface during braking with constant slowing. Measurement and Control of Chatter in Gear Drives. C. E. Rose and G. F. Hadley. Product Engineeving, v. 27, Dec. 1956, p. 168-171. Gear drive chatter is analyzed with the Geiger Torsiograph. Equations are developed for computing speed variations and eccentricity. General recommendations are given concerning gear reducers and drive motors. Distribution of the Surface Pressure Over the Friction Lining of Brakes With Rigid Shoes and Drums, and Efficiency of Such Brakes. H. Schrodcr. Acta Polytechnica (Mechanical Engilzeering Series), v. 3, no. 8, 1956, 44 p. (TI Ac81 Vis.) Friction Drive for Precision Positioning. L. A. Smitzer. machine Design, v. 29, May 30. 1957, p. 73-75. Design factors and principles in the deveiopment of a friction clutch system for precision control of starting and stopping. Friction Hoist Design Considerations. G. L. Tiley. Canadian Mining and Metallurgical Bulletin, v. 50, June 1957, p. 326-333; Canadian Institute of Mining and Metallurgy, Transactions, v. 60, 1957, p, 176-183. a concise account of the underlying principles of friction hoist design, and an attempt to develop a logical method of approaching the problem.