Chapters

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1. 01 A bearing does not break — it wears out statistically

   Almost every other component in this collection has a strength you check against: a stress, a limit, a safety factor.…

2. 02 From revolutions to hours

   L₁₀ comes out in millions of revolutions, which is the honest unit — a bearing does not know what time is.…

3. 03 The equivalent load: turning two forces into one

   The life equation takes a single number P, but a real bearing sees a radial force and an axial force at once.…

4. 04 The static check, which is a different failure

   Fatigue life assumes the bearing turns. A bearing that is stationary, or barely moving, under a large load fails another way entirely: the balls press…

5. 05 Choosing a bearing type

   The type is decided by the load direction and by how much misalignment the housing will give it — usually before any number is computed.…

6. 06 Sizing one, in the order that works

   Get the loads. From the gear, the belt, the payload and the arm's own weight.…

7. 07 How the calculator works, and what it does not do

   Where the numbers come from Everything here is ISO 281 as reproduced in NTN's published lifetime-calculation note: the basic rating life and its expon…