Abstract: An aerator for mixing an ambient gas with a liquid and agitating the liquid incorporates at least three bearings that are rigidly connected to an aerator housing. A propeller is driven by a central shaft that is rotatably mounted in the aerator housing using the bearings. Two bearings are located near the ends of the central shaft. At least one additional bearing is located between the ends, for example, in a intermediate position. This additional bearing may absorb some of the force that would otherwise be transferred to the bearing near the propeller end of the central shaft. The bearings are thus subjected to lower stress and may exhibit a prolonged useful lifespan.

Abstract: An apparatus for the treatment of liquid by aeration is provided. The apparatus has a motor, a propeller carried by a motor-driven shaft, an air flow passage to the propeller, bearings supporting the shaft at a location spaced from the motor and at least one bearing seal between a bearing and the propeller. In accordance with the present invention, a module for releasably carrying at least one of the bearing seals is detachably secured about the shaft to faciliate removal of at least the bearing seals from the apparatus.

Abstract: An apparatus for the treatment of liquid by aeration is provided. The apparatus has a motor, a propeller carried by a motor-driven shaft, an airflow passage to the propeller, and bearings supporting the shaft at at least one location spaced from the motor. In accordance with the present invention, an air pocket is established about at least one of the bearings for keeping liquid from the bearings as by a conical member extending over the shaft from the bearing.