Wash pumps in dishwashers are utilized to recirculate the wash liquid from the sump to the spray nozzles to be used during the operation of the dishwasher. These wash pumps are typically wet pumps, which use the liquid that they recirculate to lubricate/cool the bearing and the rotor shaft of the wash pump motor, thereby avoiding introduction of another fluid to the system.
To direct the wash liquid to the rotor shaft, a hole is traditionally placed in a bearing plate, which is positioned very close to and is directly fluidly coupled to the axis of rotation of the rotor shaft. Because the wash liquid contains particles of soil from the dishes, the particles can accumulate in the clearance between the rotor shaft and the housing over time, eventually causing physical obstruction to the rotation of the rotor shaft, thereby causing it to overheat and/or slow down or jam. This prevents proper functioning of the wash pump, and impedes the proper operation of the dishwasher.