MAE156A W14 – homework due March 11, 2014
1. An application requires a ball bearing with a 90% probability to last 7 years running at 3600rpm with a load of 400N. The manufacturer rates their bearings for 3000 hours at 500rpm.
a. What would the load rating need to be?
b. What would the basic load rating be?
2. A 6 cm long steel shaft is placed in an aluminum semi-circular section as shown below.
a. Compute the contact half width b
b. What is the maximum compressive stress?
c. What is the maximum shear stress?