Viscous Friction in Small Gaps—Calculations for Non-Contacting Liquid or Gas Lubricated End Face Seals

To analyze the power consumption of non-contacting liquid or gas lubricated end face seals it is necessary to split the power consumption into single losses. Therefore the losses caused by churning and by viscous shear of the interface film have to be calculated. The design of the sliding faces influences the power loss due to viscous shear. To demonstrate interdependence of speed and power losses as well as to confirm the validity of the equations, the measured power consumption of two non-contacting seals is broken down into single losses. Despite some necessary assumptions the conformity between measured and calculated values is adequate. A controlled minimization of single losses can be conducted. Based on the power loss due to viscous shear of the interface film a thermal analysis by means of FEA is possible.