Machine design Volume 2 - Softcover

Reseña del editor

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. 1903 Excerpt: ...transmission rope that has been in service for some time is about 0.26VZ2 pounds per foot. The splice for power transmission must be much longer in a rope than for most other purposes. Table XIu give.s lengths for good practice. Table 'xib. 63. The diameter of ropes used for power transmission depends very largely upon the size of the sheave that can be conveniently used. A rope 2 inches in diameter is the largest that is found in practice to any considerable extent. From 1£ to 2 inches in diameter are the limits of the sizes generally used where there is a large amount of power to be transmitted, and the pulleys can be made large without inconvenience, as in rope-drives connecting the main pulley of a large engine with a line-shaft, electric generator, or cable-drums of a cable railway. Smaller sizes are used for general transmission in buildings using power for manufacturing purposes. 64. The effect of the relative position of pulleys upon ropes used for power transmission is of the same nature as for flat belts. In practice, however, it is demonstrated that hemp and cotton ropes Rope Transmission of Power, by John J. Flatuer. work more satisfactorily than flat leather belts when one pulley is at a considerable distance above the other. This is doubtless largely due to the fact that a tension-carriage is nsed to take up the slack in the rope, while the belt, ordinarily operated without any device to make adjustment for stretch, soon becomes loose on the lower pulley. The weight of a leather belt for such a drive is generally greater than that of a hemp or cotton rope, which is disadvantageous for the belt. Hemp and cotton ropes are often used successfully, in factories, for directly connecting sheaves or pulleys three or four stories apart, one being...