A high performance engine has 7 main crankshaft bearings and runs at 17,500 RPM. Other data are...

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A high performance engine has 7 main crankshaft bearings and runs at 17,500 RPM. Other data are given below.Assuming the engine is running at the oil reference temperature of 40 degrees C, use Petrov's equation to determine the maximum power absorved by the main bearings. Comment on whether this would be likely in reality.Bearing Parameters:Journal diameter = 54mmBearing Axial Length = 25.4 mmRadial clearance = 0.025mmOil viscosity = VG32Oil density = 890kg m-3
Describe 3 situations where a conventional hydrodynamic bearing will be at a disadvantage or will not operate effectively.

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Robert · Accepted Answer

Solution: 
Journal diameter (d) =54mm=0.054metre 
Bearing diameter (D) =54.04mm=0.0504 metre 
Length(l)=25.40 mm=0.0254m 
l/d=0.0254/0.054=0.47 
F=8KN(Assume) 
Oil viscosity at 400C=32mPas= 32x10^-3 Ns/m2 
n=17,500 rev per min 
r=0.5d=0.50*0.054=0.027m 
c=(D-d)/2=0.02 mm=2x10-5 m(assume) 
p=F/dl 
p is in between 800 to 1000 lb per sq.

A high performance engine has 7 main crankshaft bearings and runs at 17,500 RPM. Other data are given below.Assuming the engine is running at the oil reference temperature of 40 degrees C, use...

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