Patent Application
20090004020
The invention concerns a water pump, in particular for use in garden ponds and in the field of aquaristics, according to the preamble of claim 1.
In practice, pumps are common in this field that have a motor-driven radial impeller so that the water to be pumped is deflected by a deflection angle of 90 degrees. In this way, these pumps fulfill the existing requirements with regard to the particular configurations according to which a deflection by approximately 90 degrees must generally occur. Even though such water pumps generate a relatively high delivery pressure, they have a relatively small delivery rate. If it is desired to achieve with such a pump a great delivery rate, the required power input is very high.
It is therefore an object of the present invention to provide a water pump with improved efficiency with regard to the delivery rate. This object is solved according to the invention by a water pump having the features of claim 1.
By using a pump impeller that is embodied as a diagonal impeller with a substantially conical carrier plate, the flow is guided diagonally through the impeller and is deflected by a smaller angle in comparison to a radial impeller. When conveying large quantities of water, the deflection losses remain small and the efficiency is improved. Pumps designed in this way have the advantage that at reduced pressure more water volume can be conveyed. Preferably, such pumps are therefore used in filter devices where little pressure but a high flow rate are required. By means of the improved efficiency, the pump according to the invention requires significantly less power input than the known pumps with a radial impeller. Also, the pump according to the invention with its great flow rate efficiency can be built more compact than pumps with conventional impellers. In order to obtain the same flow rate, the diameter of a conventional impeller would have to be greater by a factor 1.5. The compact configuration of the pump according to the invention enables also an especially cost-efficient manufacture because only relatively small tools, in particular, injection molds for plastics, are required.
Further advantages and details result from the dependent claims and an embodiment illustrated in the drawings that will be explained in the following; it is shown in:
The illustrated water pump has a pump housing 1 and a motor housing 2 connected thereto in a seal-tight way; together they form the complete housing of the pump. The pump housing 1 has a water inlet 3 and a water outlet 4 which are preferably centrally arranged on the top side of the pump housing. In the interior of the pump housing 1 between the water inlet 3 and water outlet 4 the pump impeller 5 configured as a diagonal impeller is arranged. The latter is shown in
The pump impeller 5 has according to the present invention a substantially conical carrier plate 6 by which the water flow, indicated by the arrows 7, is guided diagonally through the pump housing. In cooperation with the arrangement and shape of the water inlet 3 and the water outlet 4, preferably arranged essentially perpendicular to one another, the water flow 7 exits the pump in a direction deflected by approximately 90 degrees relative to the intake direction of the water flow 7. The carrier plate 6 of the pump impeller 5 defines a cone angle α of preferably 80 degrees to 100 degrees. In this way, an optimal flow deflection is achieved and the flow losses are minimized.
The illustrated embodiment is especially advantageous because the outer blade edges 8 of the impeller blades 9 extend in the diagonal direction, parallel to the direction of the water flow 7, and to the surface of the carrier plate 6. In this way, the impeller blades 9 can be matched to the contour of the stationary pump housing 1 so that they form a seal gap 10 thereat. In this special configuration, it is possible to provide with standard tolerances of the components a tight seal gap 10 between the stationary pump housing 1 and the rotating impeller 5. This leads to a minimal inner leakage flow and thus to an improved hydraulic efficiency. The pump can be designed especially compact when the seal gap 10 is arranged in the transition area between the water inlet 3 and the water outlet 4.
The pump of the illustrated embodiment is optimized with regard to its flow behavior and its smooth running in that the impeller blades 9 have an airfoil profile and the carrier plate 6 of the pump impeller 5 has a pointed rear edge 13. An excellent flow distribution when the flow is directed against the pump impeller 5 is achieved moreover in that the leading edges 14 of the impeller blades 9 facing the flow are oriented substantially perpendicularly to the flow direction of the water in the water inlet 3.
Centrally within the cone tip of the carrier plate 6 of the pump impeller 5 there is preferably a penetration 15 or a bore serving for cooling and venting purposes.
The pump impeller 5 can be produced particularly cost-efficient as an injection-molded plastic part. In order to optimize wear and gliding properties, preferably a metal ring is embedded by injection molding and serves as a bearing receptacle. The metal ring 16 is shown behind the shaft 17 in the exploded view of
The water pump according to the invention is excellently suitable because of its compact configuration, its high conveying output and its minimal power input as a circulating pump primarily for applications in which a permanent operation is required. In comparison to conventional pumps, significant energy savings are achieved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 009 495.6 | Feb 2006 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2006/012214 | 12/19/2006 | WO | 00 | 1/15/2008 |
