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Unformatted text preview: near the big end (or crank end) is taken
H2 = 1.1H to 1.25H.
2. Dimensions of the crankpin at the big end and the piston pin at the small end
Since the dimensions of the crankpin at the big end and the piston pin (also known as gudgeon
pin or wrist pin) at the small end are limited, therefore, fairly high bearing pressures have to be
allowed at the bearings of these two pins.
The crankpin at the big end
has removable precision bearing
shells of brass or bronze or steel
with a thin lining (1 mm or less)
of bearing metal (such as tin, lead,
babbit, copper, lead) on the inner
surface of the shell. The allowable
bearing pressure on the crankpin
depends upon many factors such
as material of the bearing,
viscosity of the lubricating oil,
method of lubrication and the
space limitations.The value of
bearing pressure may be taken
as 7 N/mm 2 t o 12.5 N/mm 2
depending upon the material and
Engine of a motorcyle.
method of lubrication used.
The piston pin bearing is usually a phosphor bronze bush of about 3 mm thickness and the
allowable bearing pressure may be...
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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