Question

Please show full working for my understanding. Given correct answers are:

(I) 10.2 MPa

(Ii) 84 hours

A sintered bronze cylindrical bushing is used on a shaft operating at 8 rpm. It has a diameter of 25 mm and a length of 20 mm. It is operated at a temperature of 40°C in a clean environment. (i) Calculate the maximum pressure on the bearing when the load carried is 4 kN. (ii) Calculate the expected time (in hours) it can operate before the wear is 0.1 mm when the load carried is 4 kN. (8)

Answer 1

Solution:- The solution for this problem can be obtained by using appropriate formulae as follows -

Explanation and Calculation as shown below -

Given-  N = 8 rpm, L =20 mm, D = 25 mm, F= 4 KN

Calculation ​​​​​​:-

a) The bearing pressure can be calculated as -

P = F/L. D

P = 4 x 10³/(25 x 20)

P = 10.2 N/mm²

P = 10.2 MPa