Question

For anti-friction bearing, relation between basic dynamic capacity, equivalent load and rating life is
1. \(\frac{C}{P} = (\frac{L}{L_{10}})^{\frac{1}{K}}\)
2. \(\frac{P}{C} = (\frac{L}{L_{10}})^{\frac{1}{K}}\)
3. \(\frac{C}{P} = (\frac{L}{L_{10}})^K\)
4. \(\frac{C}{P} = (\frac{L}{L_{10}})^{2K}\)

Answer 1

Correct Answer - Option 1 : \(\frac{C}{P} = (\frac{L}{L_{10}})^{\frac{1}{K}}\)

Explanation:

Dynamic Load capacity:

• It is the radial load at which the 90% of the group of apparently identical bearings run for 1 million revolutions before the evidence of the first crack.
• The fatigue life of bearing at which 90% of a sufficiently large group of identical bearings operating under identical conditions fails is called rated life.

Bearing rated life in million revolutions can be calculated by:

\(\frac{L}{L_{10}} = {\left( {\frac{C}{P}} \right)^k}\)

\((\frac{L}{L_{10}})^\frac{1}{k} = {\frac{C}{P}}\)

where, L = Life of bearing in Million revolution L10 = Rated life in Million revolutions, C = Dynamic load capacity/Basic load rating, P = Equivalent dynamic load

k = 3 for ball bearing, k = \(\frac{10}{3}\) for roller bearing