Reference kinematic viscosity

(ISO281:2007)

  ν1     :  Reference kinematic viscosity, required to obtain adequate lubrication condition, mm2/s

  ν       :  Actual kinematic viscosity at the operating temperature, mm2/s

  n       :  Speed of rotation, min-1

  D_pw :  Pitch diameter of ball or roller set, mm

  ν1 ＝ 45000n-0.83D_pw-0.5 for ｎ<1000min-1

  ν1 ＝ 4500n-0.5D_pw-0.5 for ｎ≧1000min-1

About calculation of sealed bearings.

Sealed bearing life (bearings with seals or shields on both sides) is calculated using grease lubrication.

If operated using oil lubrication, please consult NSK for further information.