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Unformatted text preview: ere will be two reactions at bearings 1 and 2, such that
F × b1
F × b2
; and H T2 = T
H T1 = T
Due to the radial force (FR), there will be two reactions at the bearings 1 and 2, such that
F × b1
F × b2
; and H R2 = R
H R1 = R
b Pull-start motor in an automobile The reactions at the bearings 2 and 3, due to the flywheel weight (W) and resultant belt pull
(T1 + T2) will be same as discussed earlier.
Now the various parts of the crankshaft are designed as discussed below :
(a) Design of crankpin
dC = Diameter of the crankpin in mm.
We know that bending moment at the centre of the crankpin,
MC = HR1 × b2
and twisting moment on the crankpin,
TC = HT1 × r
∴ Equivalent twisting moment on the crankpin,
Te = ( M C ) 2 + (TC ) 2 = ( H R1 × b2 ) 2 + ( H T1 × r ) 2
We also know that twisting moment on the crankpin, π
(d )3 τ
τ = Allowable shear stress in the crankpin.
From equations (i) and (ii), the diameter of the crankpin is determined.
Te = ...(i) ...(ii) 1168 n A Textbook of Machine Design (b) Design of shaft under the flywheel
Let ds = Diameter of the sha...
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This note was uploaded on 09/30/2012 for the course MECHANICAL 403 taught by Professor A.thirumoorthy during the Spring '11 term at Anna University Chennai - Regional Office, Coimbatore.
- Spring '11