Читать книгу Shafting, Pulleys, Belting and Rope Transmission онлайн

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In lining, whether for level or alinement, unless the shafting line consists of the same diameter of shafting throughout its entire length, though of necessity measuring from the shaft circumference to the line, always base your calculations on the shaft centers. The figures in Fig. 29 will make this point clear.

The manner of securing the ends of the line under different circumstances must be left to individual ingenuity. Only be sure that the line is so placed that the shafting adjustment shall not affect its original position with reference to the end shaft centers.

Coupling clutches, i.e., those joining two lengths of shafting into one at option, will fail, utterly or partially, if the respective shafts which bear them are out of line or level with each other. Such a condition should not be tolerated on account of the danger entailed by the inability to shut off the power in cases of emergency.

As a general rule, it is most advisable to set a clutch to take as hard a grip as it can without interfering with its releasing power. Where a clutch grips weakly, it is subject to undue wear owing to slippage, whereas a strongly regulated clutch absolutely prevents slippage wear.