ABSTRACT
Pump bearings support the hydraulic loads imposed on the impeller, the mass of impeller and shaft, and the loads due to the shaft coupling or belt drive. Pump bearings keep the shaft axial end movement and lateral deflection within acceptable limits for the impeller and shaft seal. The bearing loads consist of hydrostatic and momentum forces from the fluid, and mechanical unbalance forces from the pump rotor. The forces on the impeller are simplified into two components: axial load and radial load. In pumps with open and semi-open impellers, the axial load is normally directed towards the suction side owing to the pressure on the large area of the hub shroud. The magnitude and direction of the axial load can change from its design value if pump-out vane clearance changes due to wear, or is not set within tolerance, or if balance holes become plugged with debris.
