Festo Belt Drives 2, Промышленное обслуживание

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Job Sheet 3 – Variable-Speed Belt Drives
© Festo Didactic 54977-3C
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Figure 35. Correct variable-pitch pulleys alignment.
Figure 36 shows what happens when you try to align pulleys with different widths
using the conventional method. Because the distance between the straightedge
and the running center is not the same on each pulley, the belt is misaligned.
Figure 36. Incorrect variable-pitch pulleys alignment.
Variable-pitch pulley maintenance
Variable-pitch pulleys often require lubrication because of the friction between
the flanges and the threaded hub. Excessive lubrication must be avoided since it
can result in premature wear and component failure. Operating the pulley in one
position for an extended period of time may also cause premature wear of the
components. This makes the shifting of position more difficult. When the
variable-pitch pulley has one fixed flange, the alignment of the belts may be
influenced due to the shifting of the belt up or down the pulley groove. It is,
therefore, preferable to align the pulleys in a position that minimizes the side
wear of the belt. It is also recommended to prevent the surface of the belt to
make contact with the bottom surface of the pulley, where the threaded hub is
located.