Pump and domestic appliance having such a pump
The pump design with helical flow guide vanes and guide blades addresses inefficiencies caused by air bubbles, enhancing efficiency and reducing noise by directing water effectively to the pump chamber bottom, improving pump performance.
Patent Information
- Authority / Receiving Office
- US · United States
- Patent Type
- Applications(United States)
- Current Assignee / Owner
- E G O ELEKTRO GERAETEBAU GMBH
- Filing Date
- 2026-02-10
- Publication Date
- 2026-06-11
AI Technical Summary
Existing pumps in domestic appliances such as dishwashers and washing machines suffer from inefficiencies due to air bubbles forming 'tubes' or 'chains' that impair pump efficiency and generate noise, particularly when the pump runs dry.
The pump design incorporates flow guide vanes with a helical pitch outside the impeller, featuring guide blades to direct water efficiently to the pump chamber bottom, and a configuration that reverses or redirects the water flow by 180° or 90°, enhancing the removal of air bubbles and optimizing water flow.
The design efficiently removes air bubbles, improves pump efficiency, and reduces noise by quickly evacuating water, ensuring effective operation even when the pump resumes after a dry run.
Smart Images
Figure US20260160265A1-D00000_ABST
Abstract
Description
AREA OF APPLICATION AND PRIOR ART
[0001] The invention relates to a pump as may be installed in particular for water bearing domestic appliances such as dishwashers or washing machines. The invention additionally relates to such a domestic appliance. The pump has a pump chamber with an impeller therein, flow guide vanes running with a helical pitch radially outside the impeller. The flow guide vanes are intended to optimize water flow in a pump chamber downstream from the impeller or influence it in a desired manner.
[0002] Such a pump, likewise having such flow guide vanes, is known from EP 2 495 444 A2. These extend upwardly from an outlet from the impeller in the direction toward the inflow into a pump chamber because an outflow from the pump chamber is also arranged or provided in this direction.
[0003] WO 2014 / 198 427 A1 discloses a further pump for a water bearing domestic appliance.
[0004] EP 4 215 759 A1 discloses a diffuser for a radial turbocompressor that extends annularly about a central axis. This diffuser has an inflow which is provided along a first portion of the through-flow for radial through-flow by way of a fluid during operation. The diffuser has stationary first guide vanes. The diffuser has further, second stationary guide vanes that divide the diffuser into individual circumferential segments along a radial portion. The second guide vanes extend in the direction of through-flow from a second leading edge up to a second trailing edge.OBJECT AND ACHIEVEMENT THEREOF
[0005] The object of the invention is to provide an above-stated pump and a domestic appliance provided therewith with which problems of the prior art can be solved and it is in particular possible to optimize a flow rate of water flowing out of or ejected from the impeller in a pump chamber of the pump, in particular to remove air bubbles as quickly as possible from the pump chamber once the pump has run dry. Such air bubbles can remain in the pump chamber for a relatively long time, forming a “tube” or “chain”, and can so impair pump efficiency and above all generate unwanted noise.
[0006] This object is achieved by a pump having the features of claim 1 and by a domestic appliance provided therewith having the features of claim 15. Advantageous and preferred embodiments of the invention are the subject matter of the further claims and are explained in greater detail below, some of the features being described only for the pump or only for a domestic appliance provided with such a pump. They are, however, intended to apply by themselves and independently of one another both to such a pump and to such a domestic appliance provided therewith. The wording of the claims is incorporated into the content of the description by express reference.
[0007] The pump has a pump chamber with an inflow, an outflow, and a pump chamber bottom. At the pump chamber bottom, the direction of the water can either be reversed by 180°, as it were, relative to the longitudinal direction of the pump, or alternatively by 90° to the side, i.e., toward the outflow. The inflow is advantageously arranged centrally, as is conventional for a centrifugal pump or an impeller pump. The outflow is advantageously positioned externally in the radial direction or runs parallel to the radial direction. An impeller, advantageously driven by a pump motor, rotates in the pump chamber to convey water in the pump chamber, specifically from the inflow to the outflow. The impeller runs above the pump chamber bottom, advantageously at some distance therefrom, particularly advantageously between 20% and 120% of the diameter of an outer wall of the pump chamber. One or more flow guide vanes as explained above are furthermore arranged radially outside the impeller. In this way, they can direct or guide water emerging or ejected from the impeller as directly as possible in the desired direction or in a desired manner. The flow guide vanes are fixedly arranged and run in known manner helically with a pitch that runs in the direction of rotation of the impeller toward the pump chamber bottom. Water emerging from the impeller can accordingly be efficiently and quickly transported toward the pump chamber bottom and thus to an outflow that is arranged close to the pump chamber bottom. The pump is thus configured as an impeller pump or centrifugal pump and intakes water centrally and axially through the inflow. It furthermore conveys the water radially through the outflow.
[0008] According to the invention, the pump embodies at least one of the following three features. The first of these features is the pitch height of the at least one flow guide vane, that should be roughly in the region of the order of magnitude of the diameter of an external wall of the pump chamber. The pitch height of the flow guide vane advantageously amounts to 70% to 130% of this diameter. The pitch of the flow guide vane is particularly advantageously approximately uniform, which can bring about uniform flow in the direction toward the pump chamber bottom.
[0009] A second feature that can be provided in the invention is that at least one “guide blade” is arranged in a radially outer region of the at least one flow guide vane. This guide blade can be curved and runs such that it protrudes in an axial direction from the flow guide vane, thus is as it were placed or positioned thereon. Such a guide blade can form a kind of winglet and influence turbulence in the conveyed water, in particular such that air bubbles as mentioned above are removed. The guide blade can advantageously be thin, in particular have at least on average a thickness of between 70% and 120% of the flow guide vane. In a further development of the invention, the guide blade can be curved or arched in a similar manner to the pump chamber or with a curvature that would correspond to that of the pump chamber in this region in the case of a parallel course or a concentric course. Such a guide blade can particularly advantageously be arranged radially outside the impeller and at an axial height of an outlet from the impeller, such that it can guide water flowing out of the impeller particularly effectively at this point. It can optionally guide the water even more strongly toward the flow guide vane in order to particularly strongly impart a desired direction to the flowing water.
[0010] A third feature that can be provided according to the invention is that the pump chamber is arranged in an axial direction below the impeller such that the impeller is arranged or is located between the pump chamber bottom, on the one hand, and the inflow, on the other hand. A free end of the flow guide vane may here reach down to a distance of at most 2 cm or at most 20% of the diameter of the pump chamber away from the pump chamber bottom and may advantageously terminate even closer thereto. Contact with the pump chamber bottom should be avoided, however, such that a free end of one or each flow guide vane should be at a distance of at least 1 mm away from the pump chamber bottom.
[0011] Providing just one of the above-stated three features can by itself improve pump efficiency. Providing two or indeed three of these features makes the pump progressively more efficient. Pumping can therefore be performed more efficiently in a water bearing domestic appliance equipped in this manner and air can, for example, be more rapidly removed from the previously empty pump chamber if water is to be pumped again.
[0012] A pump may have a pump part and an electric drive motor that together form the pump. The entire water-bearing system is contained in the pump part. The drive motor only rotates the impeller in the pump chamber.
[0013] In one development of the invention, the at least one flow guide vane can be provided on a circumferential support ring or between the impeller and the pump chamber bottom. The support ring is advantageously arranged substantially below the impeller, such that it does not reach, let alone overlap with, the impeller in the axial direction. The support ring can preferably be arranged at a distance of at most 10 mm below the impeller, in particular it can be configured and / or arranged such that it directly adjoins the latter in the axial direction. The diameter of the support ring may preferably be between 80% and 120% or even between 90% and 110% of the diameter of the impeller. The two of them particularly preferably have the same diameter, in which case the best possible water flow can be achieved.
[0014] In a further development of the invention, the at least one flow guide vane can be arranged at an axial height and radially outside an outlet from the impeller, it preferably being capable of reaching with a free end up to that point. The flow guide vane is advantageously freestanding here, for example freestanding on an above-stated support ring, and can as it were directly pick up water from the impeller and guide / direct it.
[0015] In one advantageous development of the above-stated first feature, the pitch height of the at least one flow guide vane, advantageously of all the flow guide vanes, can be 80% to 120% of the diameter of the external wall of the pump chamber and particularly advantageously 90% to 110%.
[0016] In one configuration of the invention, a possible guide blade can have a front edge that can run substantially parallel, in particular exactly parallel or slightly inclined, to the axis of rotation of the impeller. The water arrives first at this front edge in its direction of circulation. In a further configuration of the invention, an upper edge of the guide blade can run at an angle of between 80° or 100°, advantageously at approximately 90°, to the front edge. This upper edge can alternatively run parallel to the flow guide vane, i.e., at a constant height thereabove. In another further configuration of the invention, a rear edge opposite the front edge can run obliquely at an angle of between 10° and 50° to the front edge. This is preferably the case for a quadrangular guide blade. It lies with one edge against the flow guide vane or is connected thereto, in particular formed in one piece therewith.
[0017] In a further development of the invention, a guide blade may not run exactly along a circular path about an axis of rotation of the impeller, but instead runs with a front edge on a smaller circular path about the axis of rotation of the impeller than the following part up to a rear edge. In this way, a radial distance of the guide blade from the axis of rotation of the impeller can become larger from the front edge to the rear edge, i.e., the distance between the guide blade and impeller can thus become larger.
[0018] A guide blade can advantageously be arranged at the start of the flow guide vane or only at most 10 mm therebehind. Preferably, just one guide blade is provided per flow guide vane.
[0019] Advantageously, a guide blade may have only 10% to 35% of its length along the helical course of the flow guide vane. In terms of absolute length, this may be between 15 mm and 40 mm.
[0020] With regard to the third feature, a free end of the flow guide vane can preferably reach down to a distance of at most 1 cm or 10% of the diameter of the pump chamber away from the pump chamber bottom. The end of the flow guide vane should not rest right against the pump chamber bottom, as this could cause hygiene problems and generate unwanted noise. It is thus advantageous for the free end not to rest right against the pump chamber bottom or for there still to be a gap of 1 mm to 4 mm.
[0021] In one advantageous development, the outflow can lead out of the pump chamber above the pump chamber bottom, particularly advantageously at a distance of 1 mm to 20 mm in the longitudinal direction of the pump. The impeller can preferably be arranged just downstream of the inflow, for example adjoin the inflow on the inside.
[0022] The pump chamber can have a length in the axial direction that amounts to between 70% and 200%, preferably between 80% and 160%, of the diameter of the pump chamber. The pump chamber is accordingly neither particularly elongate nor truncated.
[0023] In a further development of the invention, exactly two or exactly three flow guide vanes can be provided. This is considered sufficient for favorable water bearing. It is preferred for one or all of the flow guide vanes to be identically configured. Additionally or alternatively, they can be arranged evenly around the impeller.
[0024] A domestic appliance according to the invention has a previously described pump and a treatment chamber with a chamber drain therefrom, the pump being arranged downstream of the chamber drain. The domestic appliance is advantageously a dishwasher or a washing machine, i.e., a water bearing domestic appliance.
[0025] These and further features are revealed in the description and in the drawings as well as in the claims, wherein the individual features can each be realized singly or severally in the form of sub-combinations in one embodiment of the invention and in other fields, and can represent advantageous and per se protectable embodiments, for which protection is claimed here. The subdivision of the application into individual sections and sub-headings does not limit the statements made thereunder in their general validity.BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Exemplary embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings:
[0027] FIG. 1 is an oblique view of a pump according to the invention with a partially cut-away pump part including pump chamber and a flow guide vane in the pump chamber,
[0028] FIG. 2 is a slightly rotated depiction of a pump similar to FIG. 1 with a guide blade at the front region of each flow guide vane in the pump chamber,
[0029] FIG. 3 is another view of the flow guide vane with guide blade,
[0030] FIG. 4 is a plan view of the pump from the direction of an inflow into the pump chamber with flow guide vane and guide blade thereon, and
[0031] FIG. 5 is a view similar to FIG. 2 with another differently configured flow guide vane that reaches down to a pump chamber bottom.DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0032] FIG. 1 depicts a pump 11 as a centrifugal pump that has a conventional drive motor 13 at a rear end. The drive motor 13 is connected to a pump part 15 as is known per se from the prior art. The pump part 15 and drive motor 13 thus form the pump 11, the entire fluid or water bearing system being contained in the pump part 15.
[0033] An axial inflow 17 in a pump cover 18 is provided in the pump part 15. At the bottom, an outflow 19 leads off from the pump part 15, specifically to the side in a direction parallel to the radial direction. This is known from the prior art, see for example the above-stated WO 2014 / 198427 A1.
[0034] An annular pump chamber 21 runs in the pump part 15, specifically starting outside at the pump chamber cover 18 and running in the longitudinal direction of the pump 11 down to a pump chamber bottom. The above-stated outflow 19 departs outward from this pump chamber bottom and is preferably formed in one piece therewith. The pump chamber 21 is internally defined on the one hand by an inner dome 24 that has a round or round-cylindrical cross-section and, within the pump chamber bottom, protrudes from the latter. The pump chamber 21 is externally defined by a pump chamber wall 25 which is advantageously inserted somewhat above the pump chamber bottom. The pump chamber wall 25 is annularly closed and can advantageously consist of metal and have a heating element for heating the water conveyed in the pump 11. This too is known from the above-stated prior art. The front end of the pump chamber wall 25 is fastened to the pump cover 18 by way of a seal.
[0035] An impeller 28 with an impeller inlet 29 is arranged below the inflow 17. The impeller 28 has conventional impeller outlets 31 on the outside and impeller vanes 32 on the inside. Five impeller outlets 31 and five impeller vanes 32 are here provided by way of example. Viewed along the inflow 17, the impeller 28 rotates counterclockwise and ejects water taken in into the inflow 17 outward, the water then likewise circulating anticlockwise in the pump chamber 21 along helical paths, specifically to the pump chamber bottom and then out to the outflow 19.
[0036] Per se known flow guide vanes 36 are provided on a support ring 35 to transport the circulating water better or more strongly or as desired along the axial longitudinal direction of the pump 11 and onward to the pump chamber bottom 23. The support ring 35 is placed on the inner dome 24 and the impeller 28 is arranged directly thereover or adjacent thereto. The diameter of the support ring 35 exactly corresponds to that of the inner dome 24 at the point of transition and it can also correspond to the diameter of the impeller 28.
[0037] Two flow guide vanes 36 are arranged externally on the support ring 35, specifically with a pitch along the direction of circulation of the water in the pump chamber 21 away from the impeller 28 toward the pump chamber bottom. The pitch of the flow guide vane 36 is selected such that it amounts to approximately 70% to 130% of the diameter of the pump chamber wall 25, in the present case even advantageously approximately corresponds to this diameter. Good water bearing can be achieved with such a pitch or angle. Moreover, such a flow guide vane 36 can also very effectively remove any air remaining in the pump chamber after start-up of the pump 11 if the pump 11 has partially run dry and water is flowing back in. If the pitch were smaller or significantly smaller, for example if it were only 60% or less, the water ejected from the impeller 28 would no longer be so strongly deflected toward the pump chamber bottom or the water would circulate for longer and the efficiency of the pump 11 would be poorer. This is illustrated by the dashed depiction of such a flow guide vane that has a significantly smaller pitch, namely only around 60% pitch in comparison with flow guide vane 36.
[0038] If the pitch were significantly larger, for example 30% to 50% larger, the conveyed water would be too strongly deflected and the flow guide vane 36 would then act as too much of an obstacle to flow. The conveyed water would moreover impact on the pump chamber bottom 23 at too obtuse an angle and might then possibly no longer be so effectively conveyed out to the outflow 19.
[0039] It is also apparent from FIG. 1 that the flow guide vane 36 extends approximately over the axial length of the support ring 35 or is only slightly shorter. It is therefore of stable construction along its entire length thanks to its connection thereto.
[0040] While FIG. 1 shows the first above-stated feature of the invention with the specific pitch height, FIGS. 2 to 4 show, according to the second above-stated feature of the invention, how a guide blade 43 is formed on each of the flow guide vanes 36 on a pump 11 with a support ring 35 in the pump chamber 21. The guide blade 43 is formed in one piece on the flow guide vane, advantageously together with the support ring 35 as a single plastics part by plastics injection molding. It can be seen that the guide blade 43 remains within a start 38, an end 39 and an outer edge 40 of the flow guide vane 36. Its rear end projects to just before or up to the outer edge 40, but may also be shorter or longer.
[0041] As can be seen in FIG. 4, the flow guide vane 36 now has an approximately constant width and a straight edge at the start 38. The guide blade 43 has a substantially quadrangular shape. A front edge 45 is straight and advantageously runs parallel to the longitudinal axis of the pump 11. When viewed from the front, an adjoining upper edge 46 is curved in accordance with the overall curved course of the guide blade 43. The height of the guide blade 43 above the flow guide vane 36 can increase slightly from the front edge 45 up to a rear edge 47, such that the upper edge 46 may under certain circumstances run along a radial plane, for example along a plane below which the impeller outlets 31 are located. The guide blade 43 configured as a kind of winglet ensures that water ejected from the impeller 28 is introduced as uniformly as possible into the circular path of the pump chamber 21. It can furthermore break up any air bubbles or “chains” of air bubbles and so improve their removal from the pump chamber 21.
[0042] As is clear from FIG. 3, the rear edge 47 falls away sharply, in particular in comparison with the front edge 45. The two edges can, for example, be at an angle of between 30° and 50° to one another. The guide blade 43 is also considerably shorter than the flow guide vane 36, for example its length may be just 20% to 50% of that of the flow guide vane 36.
[0043] It can also be seen from the plan view of FIG. 4 that the flow guide vane 36 runs around the support ring 35 with a largely constant width. This means that the outer edge 40 of the flow guide vane 36 is at a constant distance from the pump chamber wall 25, this distance advantageously being relatively small and possibly between 1 mm and 8 mm.
[0044] The front edge 45 of the guide blade 43, on the other hand, is arranged considerably closer to the impeller 28, i.e., radially further inward, than is its rear edge 47. The curved course that can be seen may correspond to that which a circle would have at this point, for example midway between the front edge 45 and the rear edge 47. The guide blade 43 is, however, turned slightly outward at its end, so the distance between the rear edge 47 and the impeller 28 can be around 10% to 30% greater in the radial direction than that of the front edge 45. The rear edge 47 can also, but need not, end at the outer edge 40 of the flow guide vane 36. This ensures that the water ejected from the impeller 28 is forced, but not too strongly, into a circular path. This corresponds to the above-stated second feature of the invention.
[0045] FIG. 5 depicts a third feature of the invention. By way of example, a single flow guide vane 36 on the support ring 35 is shown here, which flow guide vane 36 extends well beyond the support ring 35 in the longitudinal direction toward the pump chamber bottom 23. One end 39 of the flow guide vane 36 ends just a few millimeters above the pump chamber bottom 23. In this case, the greatly elongated flow guide vane 36 simply rests against the inner dome 24. Alternatively, the support ring 35 could also be very greatly lengthened in this direction, such that it could likewise also reach to just before the pump chamber bottom 23. The pitch of this very long flow guide vane 36 may be approximately constant, in particular as defined in the above-stated first feature of the invention. This flow guide vane 36 can ensure that water circulating in the pump chamber 21 is actually directed very quickly and very directly in the direction of the pump chamber bottom 23 or toward the pump chamber bottom 23, so that it can then exit the pump 11 at the outflow 19.
[0046] It is theoretically also possible to provide two such very long flow guide vanes in the pump 11 of FIG. 5. In general and advantageously, however, only one such long flow guide vane 36 is provided. Alternatively, one or two additional short flow guide vanes similar to those shown in FIG. 1 could also be provided. In a further alternative configuration, at least one of the plurality of flow guide vanes in the pump 11 of FIG. 5 may additionally also have a guide blade similarly to FIGS. 2 to 4 at the start of a flow guide vane, i.e., radially outside the impeller 28.
Claims
1. A pump for domestic appliances such as dishwashers or washing machines, said pump having:a pump chamber with an inflow, an outflow, and a pump chamber bottom,an impeller for conveying water in said pump chamber, said impeller running above said pump chamber bottom, andat least one flow guide vane radially outside said impeller, said at least one flow guide vane being arranged stationarily and run helically with a pitch running ina direction of rotation of said impeller toward said pump chamber bottom, said pump being configured with said impeller to function as a centrifugal pump with a central axial intake of said water to be conveyed through said inflow, and with a radial discharge of said water to be conveyed through said outflow,wherein:a) a pitch height of said at least one flow guide vane amounts to 70% to 130% of a diameter of an external wall of said pump chamber, and / orb) at least one guide blade is provided, one said guide blade being arranged in a radially outer region of said at least one flow guide vane, said at least one guide blade being curved and protruding in an axial direction from said flow guide vane, and / orc) said pump chamber is arranged in an axial direction below said impeller such that said impeller is arranged between said pump chamber bottom and said inflow, a free end of said at least one flow guide vane reaching down to a distance of at most 2 cm or 20% of a diameter of said pump chamber away from said pump chamber bottom.
2. The pump as claimed in claim 1, wherein said at least one flow guide vane is provided on a circumferential support ring or between said impeller and said pump chamber bottom, said support ring being arranged at a distance of at most 10 mm below said impeller.
3. The pump as claimed in claim 2, wherein said support ring is arranged directly adjacent to said impeller.
4. The pump as claimed in claim 2, wherein a diameter of said support ring amounts to between 80% and 120% of a diameter of said impeller.
5. The pump as claimed in claim 1, wherein said at least one flow guide vane is arranged at an axial height and radially outside an outlet from said impeller, said at least one flow guide vane having a free end, reaching with said free end up to said impeller.
6. The pump as claimed in claim 1, wherein said pitch height of said at least one flow guide vane amounts to 80% to 120% of a diameter of an external wall of said pump chamber.
7. The pump as claimed in claim 1, wherein said at least one guide blade has a front edge running substantially parallel to an axis of rotation of said impeller.
8. The pump as claimed in claim 7, wherein said upper edge runs at an angle of between 80° or 100° to said front edge.
9. The pump as claimed in claim 8, wherein said at least one guide blade has an opposite rear edge, said opposite rear edge running obliquely at an angle of between 10° and 50° to said front edge.
10. The pump as claimed in claim 7, wherein said at least one guide blade is running in non-parallel manner along a circular path about an axis of rotation of said impeller, but instead runs with said front edge on a smaller circular path about said axis of rotation of said impeller than a following part up to a rear edge of said at least one guide blade.
11. The pump as claimed in claim 10, wherein a radial distance of said guide blade from said axis of rotation of said impeller becomes larger from said front edge to said rear edge.
12. The pump as claimed in claim 1, wherein one said at least one guide blade has only 10% to 35% of its length running along said helical course of said flow guide vane.
13. The pump as claimed in claim 1, wherein a free end of said flow guide vane reaches down to a distance of at most 1 cm or 10% of a diameter of said pump chamber away from said pump chamber bottom.
14. The pump as claimed in claim 1, wherein said outflow leads out of said pump chamber above said pump chamber bottom.
15. The pump as claimed in claim 1, wherein said impeller is arranged just downstream of said inflow, said pump chamber having a length in an axial direction amounting to between 70% and 200% of a diameter of said chamber.
16. The pump as claimed in claim 1, wherein exactly two or exactly three said flow guide vanes are provided.
17. The pump as claimed in claim 1, wherein all said flow guide vanes are identically configured and / or arranged uniformly around said impeller.
18. A domestic appliance with a pump as claimed in claim 1, wherein said domestic appliance has a treatment chamber with a chamber drain out of said treatment chamber, said pump being arranged downstream of said chamber drain.