Ball bearings vs sleeve or journal bearings


  • The ball bearing is described in the left illustration.
  • The illustration on the right shows a sleeve or journal bearing

When do you make the change from anti-friction ball and roller bearings to hydrodynamic (sleeve) bearings in a centrifugal pump?

  • Any time the DN number exceeds 300,000. To get the DN number all you have to do is multiply the bearing bore by the shaft rpm.
  • If the standard bearings fail to meet an L10 life of 25,000 hours in continuous operation or 16,000 hours at maximum axial and radial load and rated speed.
  • If the product of the pump horsepower and speed in rpm is 2.7 million or greater.



  • On February 14, 2018