Question:-
An oil ring bearing of transmission shaft of 50mm diameter in which journal rotates at 1450 rpm, radial clearance and bearing pressure are 20 micron and 4N/mm2. If Sommerfeld number is 0.0637, the viscosity of lubricant is :
Option (A)
5.75cp
Option (B)
6.75cp
Option(C)
15.75cp
Option(D)
16.75cp
Correct Option:
(B)
Question Solution:
S = (r/c)2 . (mns/p)
0.0637 = {25 / (20 x 10-3}2 {1450/60) x {1 / (4 x 106)}m
m = 6.75 x 10-3 Pa.s
= 6.75 x 10-2 Poise = 6.75 cp
question-answer-faq-9285