Question

In the design of connecting rod small end bearing, the value of permissible bearing pressure to be used is:
1. Less than that used for big end bearing
2. More than that used for big end bearing
3. Equal to that used for big end bearing
4. None of the above

Answer 1

Correct Answer - Option 2 : More than that used for big end bearing

P_b = 10.5 to 15 MPa (for small end bearing)

P_b = 7 to 12.5 MPa (for big end bearing)

For the same maximum gas load, projected area is smaller at piston pin bearing, so P_b is higher at piston pin end as compared to crank pine end.