The Gasoline Automobile Volume 1

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. 1916 Excerpt: ... for Silent Chain Drive Design.--The following rules for guidance in the design of silent chain camshaft drives were given by P. L. Morse in a paper presented to the S. A. E., Indiana Section: (1) The triangular drive is cheaper than double drives and takes less room; (2) use the shortest centers possible between crank and camshaft; (3) drive from crankshaft to camshaft, and then to accessory shaft, not to camshaft through the accessory shaft; (4) chain wrap should be not less than five teeth; (5) provide adjustment, generally easiest on the accessory shaft; (6) use an odd number of links in the chain, and an odd number of teeth in the crankshaft and accessory drive shaft sprocket when possible; (7) provide an oil lead from the general oiling system leading to the inside of the chain; (8) design the chain case so that the chain can be made endless, and when on, the wheels can be put in place; (9) if adjustment is provided without taking off the gearcase, provide a convenient means of feeling the chain to adjust to the right tension. Sufficient room must be allowed in the chain case so that in the event of chain breakage the chain can pile up at the lowest point of the housing without danger of injuring the housing. This requires a space between the top of the tooth and the housing slightly greater than the depth of the chain. The housing should have a clearance of 1% inches on the slack side of the chain. A simple method of accurately timing the valve gear (which can also be used where the camshaft drive is by spur or helical gears) is illustrated in Fig. 185. The sprocket on the camshaft is provided with a dummy hub, and the flange on this hub and the web of the sprocket are each provided with three oblong holes inclined against each other, through which a...