VI
SOME PRACTICAL KINKS[4]
Fig. 56.
A pulley on one of the motors at a certain plant had been giving some trouble by becoming loose and working its way along the shaft toward the motor bearing. Each time the pulley became loose, the set-screw was loosened, the pulley put back in position, the set-screw made tight and the motor started. After a few trials it was found that this would not prevent the pulley from working its way along the shaft. In order to overcome this difficulty the pulley was placed in its proper position, a line was drawn around the shaft close to the hub and, after the line was scribed, the pulley was removed and the shaft was burred upon the line as shown at B, Fig. 56. The pulley was then put back and driven close up to the burred line, the set-screw made tight and the pulley is now running without any apparent tendency to travel from its proper position. It will be seen that the position of the set-screw as indicated by the line at A is a poor one and calculated to give plenty of trouble at the most inopportune time.
[4] Contributed to Power by Wm. Kavanagh.
Not long ago a cast-iron pulley had to move along a countershaft in order to make room for a pulley of another diameter. The pulley had not been on the shaft long, so it was thought that little work would be required to move it. A heavy bar was placed against the hub and a sledge hammer was used to strike the bar. After an hour and a half of heavy work the pulley was not moved over 1 inch (it had to be moved 16 inches), so it was suggested that a Bunsen burner be attached to a gas pipe by means of a hose and placed beneath the hub. The plan was immediately adopted. The burner was placed beneath the hub, the gas lit and allowed to heat the hub. After about twenty-five minutes it was found that a blow from the bar was sufficient to move the pulley. The pulley was moved the 16 inches inside of twenty minutes.
