Theoretical and Numerical Investigation of Reduction of Viscous Friction in Circular and Non-Circular Journal Bearings Using Active Lubrication

Reducing friction losses is one of the most common ways to improve fluid film bearings, whose adjustable design provides additional opportunities their dynamic and tribological properties. Previous studies have shown possibility reducing viscous in actively lubricated bearings by adjusting rotor position. This work a theoretical justification for mechanism this effect cases purely laminar lubricant flows journal bearings. The operating modes connected with transition turbulent phenomena occurrence Taylor vortices are beyond scope paper. Conditions that ensure minimization hydrodynamic hybrid hydrostatic parts determined based on equations describing film. In non-adjustable plain minimum achieved centered shaft position actually unstable due resulting forces configuration. further reduction possible combining thickness pressure distributions. Recombining them, along adjustment position, allows optimization distribution shear stresses As result, caused rotation can be partially compensated gradient, torque-resisting rotation. addition, benefits obtained state reduced flow power its pumping. A series numerical calculations elliptical, 3-, 4-lobe show non-circular bores provide variability premise optimizing bearing parameters. Four-lobe demonstrated best ability among considered designs. results used as basis geometry both active passive designs friction.