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4 Determine the equivalent load and speed
Catalogues usually give rated loads for bearings running at constant speed with a steady radial load. If your bearing satisfies these conditions then continue to the next step, "Determine required life".

If the load is not radial and/or the load is not constant and/or the speed is not constant you must determine P, the equivalent dynamic bearing load and N, the equivalent nominal bearing speed before continuing to the next step. There are several cases to consider:

  1. Combining axial and radial loads
  2. Fluctuating load at constant speed
  3. Fluctuating speed at constant load
  4. Both load and speed vary