Explanation:
The given data is as follows.
Length (l) = 37.5 mm, Journal diameter (d) = 75 mm
Diameter of bushing (D) = 75.1 mm, Speed (N) = 720 rpm,
Load (F) = 2 kN
Dynamic viscosity of SAE 20 at is 12.2 cp
Clearance =
c =
= 0.05 mm
Bearing pressure will be calculated as follows.
Bearing pressure (p) =
=
=
Now, sommerfield number (S) will be calculated as follows.
S =
=
= 0.006
As,
Now, using Raimondi and John Boyd data the values for other variables will be obtained.
Minimum film thickness variable = = 0.03
Therefore, minimum film thickness
= 0.0015 mm
As, = 0.126
Hence, maximum lubricant pressure will be calculated as follows.
=
Due to friction, the heat loss rate will be as follows.
kW
According to coefficient of friction variable =
f =
=
= 0.000813
Therefore, heat loss will be calculated as follows.
Heat loss =
= 4.6 Watt