20_ch 17 Mechanical Design budynas_SM_ch17

# 20_ch 17 Mechanical - budynas_SM_ch17.qxd 17:29 Page 439 FIRST PAGES 439 Chapter 17(b The fully developed friction torque on the ﬂywheel using

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Unformatted text preview: budynas_SM_ch17.qxd 12/06/2006 17:29 Page 439 FIRST PAGES 439 Chapter 17 (b) The fully developed friction torque on the ﬂywheel using the ﬂats of the V-belts is Tﬂat = Fi 1.637 − 1 exp( f θ ) − 1 = 60(94.6) exp( f θ ) + 1 1.637 + 1 = 1371 lbf · in per belt The ﬂywheel torque should be Tﬂy = m G Ta = 5.147(586.9) = 3021 lbf · in per belt but it is not. There are applications, however, in which it will work. For example, make the ﬂywheel controlling. Yes. Ans. 17-21 (a) S is the spliced-in string segment length De is the equatorial diameter D is the spliced string diameter S De δ is the radial clearance S + π De = π D = π ( De + 2δ ) = π De + 2πδ D From which δ= S 2π The radial clearance is thus independent of De . δ= 12(6) = 11.5 in 2π Ans . This is true whether the sphere is the earth, the moon or a marble. Thinking in terms of a radial or diametral increment removes the basic size from the problem. Viewpoint again! (b) and (c) Dp 60" dp Pitch surface Table 17-9: For an E210 belt, the thickness is 1 in. 1" 0.716" 210 + 4.5 210 4.5 − = π π π 4.5 2δ = π 4.5 δ= = 0.716 in 2π d P − di = ...
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## This note was uploaded on 12/13/2011 for the course EML 3013 taught by Professor Shingley during the Fall '11 term at UNF.

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