derivation of formula
TRANSCRIPT
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 1/7
UEME 3 Mechanical Engineering De
Department of Mechanical and Materials Engineering, UTAR
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 2/7
=
=
=
= −
=
D
O 2
M
O 1
dC
S
= −
=
= −
MO 2 = S
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 3/7
Length of open belt
D
O 2
E
O 1
dJ
F
GH
Length of arc JE =
Length of arc FK =
For small value of , =
Length of arc JE = −
Length of arc FK = −
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 4/7
Length of belt = Length of arc GJE + EF + Length of arc FKH + HG
D
O 2
E
O 1
dJ
F
K
GH
L = 2(Length of arc JE + EF + Length of arc FK)
L = 2
−
+ S +
−
L = 2S +
− +
−
L = 2S + − −
L = 2 −
+ −
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 5/7
L = 2 −
+ −
L = 2 −
+ −
L = 2 C − −
⋯ . + −
Binomial ex
L = 2 C −
+ −
Neglecting higher order term
L = 2 C - −
−
L = 2 C 1.57 −
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 6/7
Important formula for V beltIdeal speed 1219 m/min
=
= 2 1.57 − , = + −3 −
, = 4 6.28
= 180 2 − −
= 180 2 − −
Length of span, =
D2 < C < 3(D2 + D1)
Gear type or chain if belt speed < 304.8 m/min
Figure 7-9 - Figure 7-15 Table 7-1
8/16/2019 Derivation of Formula
http://slidepdf.com/reader/full/derivation-of-formula 7/7
Important formula for Chain driveTwo strands : Factor = 1.7Three strands : Factor = 2.5Four strands : Factor = 3.3
= 2 +
−
=
+
+ −
=
= 180 2 − −
= 180 2 − −
Table 7-4 – Table 7-9