Читать книгу Shafting, Pulleys, Belting and Rope Transmission онлайн
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Fig. 25.
The following method avoids the taking down and putting back, provides an easy means for loosening up the pulley that has seized, and improvises, as it were, a lathe for filing and polishing the shaft.
Fig. 26.
In Fig. 26, A is the loose pulley that has seized. Throw off both the belt that leads from the main shaft to pulleys A, B and the belt that leads to the driven machine from the driving pulley C. Tie, or get somebody to hold, an iron bar in pulley A at side a, as shown in Fig. 27, over an arm of the pulley, under the shaft, and resting against the timber, ceiling, wall or floor, in such a way as to prevent the pulley from turning in one direction, as shown in Fig. 27. Now, with another bar, of a sufficient length to give you a good leverage, take the grip under a pulley arm and over the shaft in the tight pulley B at b, which will enable you to work against the resistance of the bar in the loose pulley A.
Fig. 27.
With enough leverage, this kind of persuasion will loosen the worst of cases. Take the bars out and move B sufficiently to the right to allow A to take B's former position. Secure B by means of its set-screws in its new position and, by means of a piece of cord, fasten an arm of A to one of B's. It is evident that by throwing the main-shaft belt on to A it will, through A's cord connection with B, which is screwed to the shaft, cause the shaft to revolve, thus enabling you to file up and polish that portion of it formerly occupied by A. To prevent the countershaft from side-slipping out of hanger-bearing D1, get somebody to hold something against hanger-bearing D2 at E; or fasten a piece of wire or cord on the countershaft at F and the hanger D1, so as to prevent side-slipping while not interfering with revolution.