Subtopic: Design and selection of machine elements – gears, pulleys, chains and sprockets and belts
Question Statement:
A deep groove ball bearing carries a radial load of $4.5\text{ kN}$ at a speed of $600\text{ rpm}$. If the basic dynamic load rating of the bearing is $C = 27\text{ kN}$, calculate the rating life $L_{10h}$ of the bearing in $\text{hours}$.
Answer Key:
6000
Step-by-Step Solution & Explanation
For ball bearings ($p = 3$):
Life in millions of revolutions:
$L_{10} = \left( \frac{C}{P} \right)^p = \left( \frac{27}{4.5} \right)^3 = (6)^3 = 216\text{ million revolutions}$
Life in operating hours:
$L_{10h} = \frac{L_{10} \times 10^6}{60 \times N} = \frac{216 \times 10^6}{60 \times 600} = \frac{216 \times 10^6}{36000} = 6000\text{ hours}$