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Unformatted text preview: o the flywheel weight,
W b1 b2
MV = V1· b2 = V2 · b1 =
∴ Resultant bending moment, MR = ( M H ) 2 + ( M V ) 2
We know that twisting moment on the shaft,
T = FT × r
∴ Equivalent twisting moment,
(M R )2 + T 2
We also know that equivalent twisting moment,
(d )3 τ
From equations (i) and (ii), the diameter of shaft under the flywheel (ds) may be determined.
Example 32.4. Design a plain carbon steel centre crankshaft for a single acting four stroke
single cylinder engine for the following data:
Te = 1176 n A Textbook of Machine Design Bore = 400 mm ; Stroke = 600 mm ; Engine speed = 200 r.p.m. ; Mean effective pressure = 0.5
N/mm2; Maximum combustion pressure = 2.5 N/mm2; Weight of flywheel used as a pulley = 50 kN;
Total belt pull = 6.5 kN.
When the crank has turned through 35° from the top dead centre, the pressure on the piston is
1N/mm2 and the torque on the crank is maximum. The ratio of the connecting rod length to the crank
radius is 5. Assume any other data required for the design.
Solution. Given : D = 400 mm ; L = 600 mm or r = 300 mm ; pm = 0.5 N/mm2 ; p = 2.5 N/mm2 ;
W = 50 kN ; T1 + T2 = 6.5 kN ; θ = 35° ; p′ = 1N/mm2 ; l / r = 5
We shall design the cranks...
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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