Patent ID: 8182214

Claim:
A pond pump with an impeller ( 2 ) rotating about a rotation axis (X) in a pump housing ( 1 ), wherein the pump housing ( 1 ) includes a suction inlet ( 11 ) arranged axial to the impeller ( 2 ), a pressure outlet ( 14 ) for the water to be conveyed oriented radially to tangential to the impeller ( 2 ) as well as a housing segment between suction inlet ( 11 ) and pressure outlet ( 14 ), wherein the impeller ( 2 ) comprises a radially oriented circular disc ( 22 ) with vanes ( 21 ) arranged on one side thereof, wherein the housing segment associated with the vane ( 21 ) equipped open side of the impeller ( 2 ) is a surface formed as a counterflow plate ( 12 ), wherein flow channels ( 23 ) are formed between the vanes ( 21 ), the disc ( 22 ) and the counterflow plate ( 12 ), wherein the flow channels ( 23 ) have a cross-section, which decreases in the direction of flow from the radial inner side towards the outer side, wherein the counterflow plate ( 12 ) is in the form of a wide open conical surface segment with an angle (α) between 5° and 20° to the plane oriented radial to the rotation axis (X) in the direction of the impeller, wherein the height of the vanes ( 21 ) measured axial to the rotation axis (X) of the impeller ( 2 ) reduces going from the radial inner side towards the outer side, so that the open side of the impeller ( 2 ) is provided spaced apart from the counterflow plate ( 12 ) with an essentially even gap (s), and wherein the flow channels ( 23 ) formed between the vanes ( 21 ) from the radial inner side to the outer side of the impeller exhibit essentially the same breadth (b).