Items related to A textbook on steam engineering Volume 1
Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1902 Excerpt: ... to some extent, as are also belts made of a number of layers of duck sewed together and impregnated with a preparation rendering them waterproof. These belts, in accordance with the number of layers or "plys," are called two-ply, three-ply, etc. Four-ply cotton and duck belting is about equal to single leather belting, and eight-ply to double leather belting. 22. Rubber belts are especially adapted for use in damp or wet places; they will endure a great degree of heat or cold without injury, are quite durable, and are claimed to be less liable to slip than leather belts. CALCULATIONS FOR BELTS. 23. To Find the Length of a Belt.--In practice, the necessary length for a belt to pass around pulleys that are already in their position on a shaft is usually obtained by passing a tape line around the pulleys, the stretch of the tape line being allowed as that necessary for the belt. The lengths of open-running belts for pulleys not in position can be obtained approximately as follows: Rule 7.--The length of a belt for open-running pulleys equals 3 times one-half the sum of the diameters of the pulleys plus 2 times the distance betwcen the centers of the shaft. Let D = diameter of one pulley in inches; d = diameter of the other pulley in inches; L = distance between the centers of the shafts in inches; B = length of the belt in inches. Example.--The distance between the centers of two shafts is 9 feet 7 inches; the diameter of the large pulley is 36 inches and the diameter of the small one is 14 inches; what is the necessary length of the belt? Solution.--Applying the rule just given and substituting the values given, we have, since 9 feet 7 inches = 115 inches, + 2 X 115 = 311i in., or 25 ft. 11J in. Ans. The length of crossed belts cannot be determined...
"synopsis" may belong to another edition of this title.