Chapter 19: Flexible Machine Elements

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Chapter 19 Flexible Machine Elements
Scientists study the world as it is engineers
create the world that has never been. Theodore
von Karmen
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Flat Belt
Figure 19.1 Dimensions, angles of contact, and
center distance of open flat belt.
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Weighted Idler
Figure 19.2 Weighted idler used to maintain
desired belt tension.
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Synchronous Belt
Figure 19.3 Synchronous, or timing, belt.
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V-Belt in Groove
Figure 19.4 V-belt in sheave groove.
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Overload Service Factors
Table 19.1 Overload service factors f1 for
various types of driven unit.
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Pulley Design Considerations
Table 19.2 Recommended minimum pitch diameters
of pulley for three belt sizes.
Table 19.3 Recommended pulley dimensions in
inches for three electric motor sizes.
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Arc Correction Factor
Table 19.4 Arc correction factor for various
angle of loss in arc of contact.
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Power Ratings for V-Belts
Table 19.5 Power ratings for light-duty V-belts.
(a) 2L section with wt 1/4 in and ht1/8 in.
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Power Ratings for V-Belts (cont.)
Table 19.5 Power ratings for light-duty V-belts.
(b) 3L section with wt 3/8 in and ht1/4 in.
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Power Ratings for V-Belts (cont.)
Table 19.5 Power ratings for light-duty V-belts.
(c) 4L section with wt 1/2 in and ht9/32 in.
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Center Distance for V-Belts
Table 19.6 Center distances for various pitch
diameters of driver and driven pulleys. (a) 3L
type of V-Belt.
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Center Distance for V-Belts (cont.)
Table 19.6 Center distances for various pitch
diameters of driver and driven pulleys. (b) 4L
type of V-Belt.
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Wire Rope
Figure 19.5 Cross-section of wire rope.
Figure 19.6 Two lays of wire rope. (a) Lang (b)
regular.
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Wire Rope Data
Table 19.7 Wire rope data.
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Minimum Safety Factors
Table 19.8 Minimum safety factors for a variety
of wire rope applications.
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Effect of D/d Ratio
Figure 19.7 Percent strength loss in wire rope
for different D/d ratios.
Figure 19.8 Service life for different D/d
ratios.
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Allowable Bearing Pressures
Table 19.9 Maximum allowable bearing pressures
for various sleeve materials and types of rope.
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Rolling Chains
Figure 19.9 Various parts of rolling chain.
Figure 19.10 Chordal rise in rolling chains.
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Strength of Rolling Chains
Table 19.10 Standard sizes and strengths of
rolling chains.
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Chain Power Ratings
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Rolling Chain Data
Table 19.12 Service factors for rolling chains.
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Dragline
Figure 19.11 Typical dragline.