Question

A Ball bearing is anticipated to have a life of 400 million revolutions under an equivalent radial load of 10 kN with a reliabilt of 90%
With a reliability of 60% under the load of 22 kN, the expected life is

Answer 1

$\text{For}{P}_e\text{= 22 kN,}{L}_{90}\text{= 37.56 million revolutions}$

$\frac{L}{L_{90}}={\left(\frac{ln\left(1/R\right)}{ln\left(1/R_{90}\right)}\right)}^{1/1.17}$

$\text{R = 0.6,}{L}_{60}\text{= ?}$

$L_{60}=37.6{\left(\frac{ln\left(1/0.6\right)}{ln\left(/1R_{90}\right)}\right)}^{1/1.17}$

$L_{60}\text{=144.93 million revolutions}$