TECHNICAL FIELD

This disclosure relates generally to devices and methods for filtering aquarium water. More specifically, this disclosure relates to an improved impeller for use an aquarium filter pump.

BACKGROUND

To maintain an ecological balance within an aquarium, it is necessary to keep the water in the aquarium clean. Cleaning is often accomplished by pumping water from the aquarium to a filter device. The filter device will clean the water by having it pass through a filter medium, and then the cleaned water is returned to the aquarium. Such filtering devices generally include an internal pump driven by an electric motor for pumping the water through the filter medium. Improvements are desirable by increasing the flow rates through the pump, without increasing the impeller size to allow for compact impeller designs.

SUMMARY

An impeller for use in an aquarium filter pump that improves the prior art is provided.

An impeller includes a shaft and a plurality of impeller blades radially extending from the shaft. Each of the impeller blades includes opposite blades faces; a free edge remote from the shaft; first and second opposite edges extending from the shaft to the free edge, wherein the blade faces are bordered by the first and second edges and the free edge; and a depression in each of the blade faces. The depression is at a maximum depth within the respective blade face at one of the edges.

In example embodiments, the shaft has a longitudinal axis, and each blade is along a plane containing the first and second edges. Each plane also contains the longitudinal axis of the shaft.

In many examples, the free edge, first edge, and second edge, are straight edges.

In some embodiments, the depression has a periphery with a shape of two opposite parallel sections that round to a vertex region.

In examples of depressions that have a vertex region, in some implementations, the vertex region is adjacent to the shaft, and the free edge is a deepest portion of the depression.

In some implementations, the depression has a periphery forming a curved shaped with a vertex region adjacent the first edge, and the second edge is a deepest portion of the depression.

For some embodiments, the depression increases in depth as the depression extends from adjacent the shaft to the free edge.

In some embodiments, there are no more than four blades.

In some embodiments, there are at least three blades and no more than four blades.

In another aspect, an impeller assembly for use in an aquarium filter pump is provided. The impeller assembly includes a shaft with a longitudinal axis, a rotor mounted on the shaft, and an impeller mounted on the shaft. The impeller has at least three blades radially extending from the shaft. Each blade is along a plane containing the longitudinal axis of the shaft. Each blade has an opposite blade face. Each blade has straight, opposite first and second edges extending from the shaft and a straight free edge extending between the first and second edges. Each blade face has a depression.

In some examples, the depression has a periphery with a shape of two opposite parallel sections that round to a vertex region.

In some examples, the vertex region is adjacent to the shaft, and the free edge is a deepest portion of the depression.

In some examples, the depression has a periphery forming a curved shaped with a vertex region adjacent the first edge, and the second edge is a deepest portion of the depression.

In some implementations, the depression increases in depth as the depression extends from adjacent the shaft to the free edge.

In another aspect, a method of pumping water for an aquarium filter is provided. The method includes rotating an impeller in an aquarium to draw water into the filter. The step of rotating the impeller includes rotating blades. Each blade includes opposite blade faces; a free edge; first and second opposite edges, with the blade faces being bordered by the first and second edges and the free edge; and a depression in each of the blade faces. The depressions aid in pushing the water.

A variety of additions aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based.

