Question

For a SKF Single-Row 02-80 mm Deep-Groove ball bearing, an axial load Fa of 7650 N and a radial load Fr of 15 kN are applied with the

inner ring stationary. Estimate the bearing life at a speed of 740

rev/min with a reliability of 99.99%. SKF rates its bearings for 1 million

revolutions. The Weibull parameters are, x0 = 0.02, θ = 4.459, and b =

1.483

Answer 1

given Data:

Rotational speed $n = 740 \frac{rev}{min}$

Dynamic equivalent radial load

$P_r = XF_r + YF_a =0.02\times 15000 +1.483\times 7650 =11644.95 N$

$C_r = 7650 N$

Bearing service life (L_10h) is calculated

$L_{10h}=\frac{10^6}{n}(\frac{C_r}{P_r})^{3}$

$L_{10h}=\frac{10^6}{740}(\frac{11644.95}{7650})^{3} = 4766.47$ hr