Pump and domestic appliance having such a pump

Abstract

A pump for a washing machine comprises: a pump chamber with an inlet, an outlet and a pump-chamber base; an impeller for conducting water in the pump chamber; and optionally a plurality of flow-directing vanes radially outside the impeller, the vanes being stationary and extending helically towards the pump-chamber base. The pump is designed in the form of a centrifugal pump. According to the invention, at least one curved or bent guide blade is arranged either on at least one flow-directing vane or on a support ring below the impeller.

Description

[0001] Pump and household appliance with such a pump

[0002] FIELD OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a pump, such as can be installed in particular in water-conducting household appliances such as dishwashers or washing machines. Furthermore, the invention relates to such a household appliance. The pump has a pump chamber with an impeller therein, with flow guide vanes extending radially outside the impeller with a helical pitch. The flow guide vanes are intended to optimize or influence the water flow in a pump chamber downstream of the impeller.

[0004] Such a pump is known from EP 2 495 444 A2, which also has such flow guide vanes. These extend from an outlet of the impeller upwards toward the inlet into a pump chamber, since an outlet from the pump chamber is also arranged or provided in this direction.

[0005] Another pump for a water-conducting household appliance is known from WO 2014 / 198427 A1.

[0006] TASK AND SOLUTION

[0007] The invention is based on the object of creating a pump mentioned above and a household appliance equipped with it, which can solve problems of the prior art and, in particular, make it possible to optimize the flow of water flowing out of or ejected from the impeller in a pump chamber of the pump, in particular to remove air bubbles from the pump chamber as quickly as possible after the pump has been running idle. Such air bubbles can remain in the pump chamber in a kind of tube or trail for a relatively long time, impairing the efficiency of the pump and, above all, generating unwanted noise.

[0008] This object is achieved by a pump having the features of claim 1 or 13, as well as by a household appliance provided therewith having the features of claim 19. Advantageous and preferred embodiments of the invention are the subject of the further claims and are explained in more detail below. Some of the features are described only for one of the pumps or only for a household appliance provided with such a pump. However, they are intended to be able to apply independently and independently of one another to both such pumps and such a household appliance provided with them. The wording of the claims is incorporated into the content of the description by express reference.

[0009] The pump has a pump chamber with an inlet, an outlet, and a pump chamber floor. At the pump chamber floor, the water direction can be reversed by either 180° relative to the longitudinal direction of the pump, or alternatively by 90° to the side, towards the outlet. The inlet is advantageously located centrally, as is usual for a centrifugal pump or an impeller pump. The outlet is advantageously located externally in the radial direction or runs parallel to the radial direction. An impeller rotates in the pump chamber, advantageously driven by a pump motor, to pump water in the pump chamber from the inlet to the outlet. The impeller runs above the pump chamber floor, advantageously at some distance from it, particularly advantageously between 20% and 120% of the diameter of an outer wall of the pump chamber.

[0010] In a first basic embodiment of the invention, one or more flow guide vanes are provided, as explained at the beginning, which are arranged radially outside the impeller. In this way, they can direct or guide water emerging from or thrown out of the impeller as directly as possible in the desired direction or in the desired manner, preferably towards the pump base. The flow guide vanes are fixedly arranged and run in a known manner in a helical manner with a pitch that runs in the direction of rotation of the impeller towards the pump chamber base, whereby they revolve at least partially, i.e. preferably only run along a partial circle. In this way, the water emerging from the impeller can be pumped efficiently and quickly to the pump chamber base and thus to an outlet that is arranged close to the pump chamber base. The pump is therefore designed as an impeller pump orIt is designed as a centrifugal pump and draws water in centrally and axially through the inlet. It then pumps the water out radially through the outlet.

[0011] According to this invention, at least one so-called guide vane is arranged on or on the at least one flow guide vane. This guide vane is bent or can be curved and runs in such a way that it protrudes at least partially from the flow guide vane in the axial direction of the pump, i.e. is so to speak attached to it or placed on it, advantageously in one piece. Such a guide vane can form a type of winglet and influence turbulence in the pumped water, in particular in such a way that the air bubbles mentioned above are removed. The guide vane can advantageously be thin, in particular at least on average have a thickness of between 70% and 120% of the flow guide vane. In a further embodiment of the invention, the guide vane can be bent or curved similarly to the pump chamber or with a bend that would correspond to that of the pump chamber in this area if it ran parallel orConcentrically arranged. Such a guide vane can be particularly advantageously positioned radially outside the impeller and at the axial level of an impeller outlet, so that it can guide water flowing out of the impeller particularly well. If necessary, it can direct the water even more strongly toward the flow guide vane, thus giving the flowing water a particularly pronounced desired direction.

[0012] The invention can improve the efficiency of the pump. In a water-conducting household appliance equipped with it, pumping can be more efficient thanks to the flow guide vane, and a guide vane can be used to remove air from the previously empty pump chamber more quickly when water is to be pumped again.

[0013] A pump can consist of a pumping section and an electric drive motor, thus forming the pump. The entire water flow is contained within the pumping section. The drive motor only rotates the impeller in the pump chamber.

[0014] Advantageously, the at least one guide vane is arranged on the side of the flow guide vane that faces away from the pump chamber floor or toward an inlet into the pump chamber. This is from the flow guide vane upwards, in particular at least partially covering the impeller in the radial direction. This allows the guide vane to optimally capture and remove air or air bubbles as they emerge from the impeller.

[0015] In one embodiment 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 floor. The support ring is advantageously arranged substantially below the impeller so that it does not reach the impeller in the axial direction or even overlaps it. Preferably, the support ring can be arranged at a maximum distance of 10 mm below the impeller; in particular, it can be designed and / or arranged such that it directly adjoins it in the axial direction. A diameter of the support ring can preferably be between 80% and 120% or even between 90% and 110% of the diameter of the impeller. Particularly preferably, both have the same diameter, thus achieving the best possible water flow.

[0016] In an advantageous embodiment of the aforementioned first feature, the pitch of the at least one flow guide vane, advantageously of all flow guide vanes, can be 80% to 120% of the diameter of the outer wall of the pump chamber. Particularly advantageously, this can be 90% to 110%.

[0017] In one embodiment of the invention, the at least one guide vane can have a leading edge that can run essentially parallel to the impeller's axis of rotation, in particular exactly parallel to it or slightly inclined, counter to the water flow caused by the impeller in the pump chamber. The water first reaches this leading edge in its direction of circulation.

[0018] Alternatively, the at least one guide vane can have a leading edge that is arranged or located on an end face of a support ring, on which the flow guide vane is arranged or integrally formed radially outward. Adjacent to the leading edge, the beginning or the foremost region of the guide vane can also be arranged on the same end face of the support ring, i.e., not yet on the flow guide vane. The flow guide vane can begin on a plane in which the end face of the support ring runs, but then connect to it radially outward.

[0019] In a first embodiment of the invention, the upper edge of the guide vane can extend at an angle of between 2° and 20° to the side of the flow guide vane on which the guide vane is arranged. Preferably, the axial height of the guide vane, which runs parallel to the impeller's rotational axis, remains approximately the same or changes by only a maximum of 10% or 15%. Thus, the guide vane has approximately the same pitch as the flow guide vane.

[0020] In a second embodiment of the invention, the upper edge of the guide vane can extend at an angle of between 80° and 90° to the impeller's rotational axis, so that the axial height of the guide vane, which runs parallel to the impeller's rotational axis, increases. Advantageously, the upper edge of the guide vane can extend at a right angle to the impeller's rotational axis.

[0021] In yet another embodiment of the invention, a rear edge of the guide vane opposite the leading edge can run obliquely at an angle of between 10° and 50° to the leading edge. This all preferably applies to a square guide vane. It rests with one edge on the flow guide vane or is connected to it, in particular formed integrally. In a further embodiment of the invention, the at least one guide vane can not run exactly along a circular path around a rotational axis of the impeller, but rather with a said leading edge starting on a smaller circular path or with a smaller radial distance around the rotational axis of the impeller than the subsequent part up to a rear edge. In this way, a radial distance of the guide vane from the rotational axis of the impeller can increase from the leading edge to the rear edge, thus increasing the distance between the guide vane and the impeller.

[0022] A guide vane can advantageously be arranged at the beginning of the flow guide vane or only a maximum of 10 mm behind it. Preferably, only a single guide vane is provided per flow guide vane.

[0023] Advantageously, a guide vane along the helical path of the flow guide vane can comprise 70% to 110% of its length, preferably 80% to 100%. In absolute length, this can be between 35 mm and 55 mm.

[0024] In a further embodiment of the invention, a guide vane can extend largely along an outer edge of the flow guide vane, or at least behind a front region, preferably corresponding to 10% to 25% of the length, or terminate this. Thus, a profile formed by the flow guide vane and the guide vane can form an angle, advantageously with approximately 80° to 100° between them.

[0025] In a first embodiment of the invention, a leading region of the guide vane can adjoin a leading edge of the at least one guide vane, with the leading edge and this leading region pointing approximately radially toward the impeller's rotational axis. The guide vane is then strongly curved inward toward the leading edge. This is very well suited for tapping air from the impeller. The efficiency of the pump is slightly impaired, but not significantly.

[0026] In another second embodiment of the invention, a leading edge of the at least one guide vane can be adjoined by a said front region of the guide vane, and the leading edge and this front region point approximately in the circumferential direction or in the tangential direction. Advantageously, the guide vane then runs overall on a circular arc, which does not necessarily have to have its center at the axis of rotation of the impeller. This ensures very good pump efficiency; the tapping of air from the impeller is somewhat impaired, but not significantly. In a further development of the invention, a leading edge or the foremost point of the guide vane can have a distance of a maximum of 10% of the length of the flow guide vane from a front region of the flow guide vane, preferably only a distance of a maximum of 5%. This means that the guide vane is located or begins well forward on the flow guide vane.This means it is quite high up and therefore close to the impeller.

[0027] In another, second, basic embodiment of the invention, no flow guide vane is provided; instead, the pump again has a pump chamber with an inlet, an outlet, and a pump chamber floor, and an impeller for pumping water in the pump chamber, with the impeller running above the pump chamber floor. A circumferential support ring is provided between the impeller and the pump chamber floor, with this support ring being arranged substantially below the impeller. The pump with the impeller is again designed to function as a centrifugal pump, and has a central axial suction of the water to be pumped through the inlet and radial outflow of the water to be pumped through the outlet.

[0028] According to the invention, at least two curved guide vanes are arranged on the support ring, with these guide vanes extending from their respective leading edges with increasing radial distance from a rotational axis of the impeller. No flow guide vane is provided here, so that a bend or curvature, preferably convex, of the guide vane simultaneously fulfills the aforementioned function of guiding the fluid as directly as possible in the desired direction or in the desired manner toward the pump base. By omitting flow guide vanes, the resistance in the pump can be reduced, and the pump design is simplified.

[0029] In a further development of the invention, all guide vanes can be designed identically. This can apply to both basic embodiments of the invention.

[0030] In a further development of the invention, the at least two guide vanes can be curved or arched in two directions. They are preferably curved or arched away from the impeller's rotational axis.

[0031] Advantageously, a plurality of guide vanes can be arranged on the support ring, preferably 6 to 10 guide vanes. These can preferably be evenly distributed and arranged in the same way on the support ring. This means that their effect on the pumped water is always the same. These multiple guide vanes can be shorter than those described above, which are each arranged on a flow guide vane. For this purpose, they can also run at a much greater angle to a direction of rotation. Their front edge, including the front area that adjoins it, can point in a radial direction or have an angle of a maximum of 20° or a maximum of 10° to it. In a central area, they can have an angle of between 30° and 60° to the direction of rotation. Near or in this central area, the guide vanes can protrude from the support ring, i.e. run freely from here.

[0032] An end region where the guide vanes advantageously run freely can have an angle of up to 20° or up to 10° to the direction of rotation. Thus, the guide vanes run in or almost in the direction of rotation at the end, so that they release the water flowing past them in a way that is as directed as possible in the direction of rotation.

[0033] In one embodiment of the invention, a guide vane is arranged halfway up a central region of the flow guide vane, whereby its length can be between 10% and 30% of the length of the flow guide vane, i.e., it is short compared to the latter. A leading edge of the guide vane is arranged either on an end face of a support ring, on which the flow guide vane is arranged radially outward, and at a smaller radial distance from the impeller's rotational axis than the flow guide vane, or on the flow guide vane itself. This design of guide vanes can be provided regardless of whether a flow guide vane is present.

[0034] It is possible for the guide vanes to not overlap each other in the direction of rotation around the impeller, or for the guide vanes to be spaced apart. This prevents excessive flow resistance.

[0035] In general, all guide vanes can be arranged evenly. This ensures consistent water flow.

[0036] Advantageously, the at least one guide vane can be arranged at least partially at axial height and radially outside an outlet from the impeller, preferably all of the guide vanes. In this case, a part of the guide vane can be arranged below the impeller towards the pump chamber floor, in particular this is the larger part of the guide vane or more than half its length and / or area. In this case, its guiding effect on the pumped water is particularly good. In an advantageous embodiment, the outlet can lead out of the pump chamber above the pump chamber floor, particularly advantageously with a distance of 1 mm to 20 mm in the longitudinal direction of the pump. Preferably, the impeller can be arranged just behind the inlet, for example connecting to the inlet on the inside.

[0037] The pump chamber can have an axial length between 70% and 200% of the diameter of the pump chamber, preferably between 80% and 160%. Thus, the pump chamber is neither particularly elongated nor compressed.

[0038] In a further development of the invention, exactly two or exactly three flow guide vanes can be provided. This is considered sufficient for advantageous water flow. It is preferred if some or all of the flow guide vanes are of the same design. Additionally or alternatively, they can be arranged evenly around the impeller.

[0039] A household appliance according to the invention comprises a pump as described above and a treatment chamber with a chamber outlet therefrom, wherein the pump is arranged behind the chamber outlet. The household appliance is advantageously a dishwasher or a washing machine, i.e., a water-conducting household appliance.

[0040] These and other features emerge not only from the claims but also from the description and the drawings. The individual features may be implemented individually or in combination in an embodiment of the invention and in other fields, and may represent advantageous and individually protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the generality of the statements made therein.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Embodiments of the invention are illustrated schematically in the drawings and explained in more detail below. The drawings show:

[0043] Fig. 1 to 3 show a first embodiment of a pump according to the invention with flow guide vanes and guide wings in side view, front view and oblique view, Fig. 4 to 15 show four further variants of a pump according to the invention with flow guide vanes and guide wings in side view, front view and oblique view.

[0044] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] Figs. 1 to 15 show five exemplary embodiments of pumps according to the invention, each in a side view, a front view, and an oblique view. All views are partially sectioned, or the front part of the pump is cut halfway open. The first pump 11a according to the invention, as shown in Figs. 1 to 3, is described in more detail overall, as it can be seen. The other pumps are described only with regard to their differences, i.e., the design of the flow guide vanes and / or guide blades, and their special features. The same reference numerals identify the same parts; the individual variants of the exemplary embodiments are distinguished by different lowercase letters at the end.

[0046] A first embodiment of a pump 11a according to the invention, as shown in Figs. 1 to 3, has a drive motor 13a at the rear, to which a pump part 15a is attached from the front. The drive motor 13a is not of interest to the invention, and the pump part 15a is only partially of interest. At the front, the pump 11a has a central and axial inlet 17a formed in a pump cover 18a. At the rear of the pump part 15a, in front of the drive motor 13a, an outlet 19a protrudes in the radial or tangential direction; it is designed as a nozzle, similar to the inlet 17a.

[0047] The pump chamber 21a is located in the pump section 15a, with a pump chamber floor 23a, above which an inner dome 24a protrudes centrally. The pump chamber 21a is bounded radially outward by a pump chamber wall 25a, which here is designed as a metallic, circular heating element with external thick-film heating elements.

[0048] Located on the inner dome 24a or mounted thereon is an impeller 28a, which is designed in the conventional manner. The impeller 28a has an impeller inlet 29a, which connects directly to the inlet 17a. Radially outward, the impeller 28a has several impeller outlets 31a, each of which is divided or separated from one another by inclined impeller blades 32a. In the front and oblique views, the impeller 28a rotates counterclockwise. Up to this point, the pumps 11 of all embodiments are identical. A circumferential support ring 35a is provided on the outside of the inner dome 24a and axially below the impeller 28a or at a short distance therefrom, preferably 0.5 mm to 5 mm. The support ring 35a can, under certain circumstances, also be formed integrally or in one piece with the inner dome 24a. Four equally sized and evenly distributed flow guide vanes 36a are formed on the outside of the support ring 35a. As the side view of Fig.1 shows, they protrude approximately in the radial direction from the support ring 35a, but are inclined at an angle of between 5° and 10° to the radial direction towards the front of the pump cover 18. The flow guide vanes run in a helical shape over a circular arc of approximately 80°, so that they do not overlap, as the front view in Fig. 2 shows. They each have a start 38a and an end 39a, which are designed at an angle, i.e. do not run in the radial direction. Between the start 38a and the end 39a, they have an outer edge 40a, which can run along a circular arc around an axis of rotation of the impeller 28a, but does not necessarily have to. From Figs. 1 and 2 it can be clearly seen that water in the pump chamber 21a circulates counterclockwise in a ring and is thus transported by the flow guide vanes 36a in a helical shape towards the pump chamber floor 23a.Thus, these flow guide vanes 36a primarily serve to increase or improve the pumping efficiency of the pump 11a.

[0049] A guide vane 43a is arranged on an upper side 41a of each flow guide vane 36a, preferably formed integrally therewith. The four guide vanes 43a are approximately the same length as the flow guide vanes 36a, at least along their respective outer edges 40a. The guide vanes 43a each have a leading edge 45a, which is straight and runs almost parallel to the axis of rotation of the impeller 28a, and a front region 44a adjoining the leading edge 45. This is followed by an upper edge 46a, which runs to a rear edge 47a. This rear edge 47a can also run approximately parallel to the axis of rotation of the impeller 28a. The guide vane 43a shown here is curved inwards somewhat more tightly in the front region 44a than a circular arc around the axis of rotation of the impeller 28a, on which the guide vane 43a largely runs. The front view of Fig.Figure 2 shows that the front area 44a is curved slightly radially inward, but not very far. In this front area 44a, or with the leading edge 45a, the guide vane 43 captures air bubbles from a water flow coming directly from the impeller 28 or the impeller outlets 31a. Thus, the guide vanes 43a primarily serve to remove air bubbles or air more quickly from the pump 11a or its pump chamber 21a.

[0050] The height of the guide vane 43a above the upper side 41a of the flow guide vane 36a is approximately constant, as the side view of Fig. 1 shows. Thus, the rear edge 47a has an approximately constant height above the upper side 41a. Figs. 4 to 6 show a second pump 11b according to the invention, which differs only within the pump chamber 21b and here with regard to the configuration of guide vanes 43b on flow guide vanes 36b on the support ring 35b. The flow guide vanes 36b themselves are identical. The three views show that here too, a guide vane 43b has a front region 44b with a front edge 45b, an upper edge 46b, and at the end, a rear edge 47b. Here too, the front edge 45b and the rear edge 47b are formed approximately parallel to the axis of rotation of the impeller 28b.Furthermore, the guide wings 43b also have an approximately constant height, so that the rear edges 47b run at approximately the same distance from the upper side 41b.

[0051] The difference between pump 11b and pump 11a is that the guide vanes 43b in the front area 44b are strongly curved radially inward. The foremost area at the front edge 45b points almost radially toward the axis of rotation of the impeller 28b, so that here the guide vanes 43b are very strongly curved inward. This makes it possible to position the front edge 45b closer to the impeller 28b than in pump 11a. It can be designed to overlap, so to speak, on one end face of the inner dome 24b. Due to this strongly inwardly curved design of the front area 44b and the short distance to the impeller 28b or its impeller outlets 31b, air bubbles can be tapped and removed very directly and effectively. This means that venting times can be greatly reduced with pump 11b, and the air is removed very quickly.At the same time, a strongly inwardly curved front section 44b presents a somewhat greater flow resistance for circulating water, so that the pumping efficiency of pump 11b is somewhat reduced. Another special feature is that the guide vanes 43b of pump 11b are somewhat thinner than those of pump 11a.

[0052] Figs. 7 to 9 show a third pump 11c according to the invention. This pump is very similar to pump 11b with regard to the design of the guide vanes 43c on the flow guide vanes 36c, as the front view of Fig. 8 in particular shows. The special feature here is that the height of the guide vanes 43c increases along the path on the upper sides 41c of the flow guide vanes 36c, i.e., each guide vane 43c becomes higher up to its rear edge 47c. The increase in height is approximately 70% to 80%. Furthermore, the side view of Fig. 7 shows that an upper edge 46c of the guide vanes 43c extends in a plane that is perpendicular to the axis of rotation of the impeller 28c.

[0053] The front view of Fig. 8 shows that a front area 44c, including the front edge 45c, is again strongly curved inward, as previously described for Fig. 5. The great height of the guide vanes 43c, which increases over time, can improve the removal of air from the pump chamber 21c. Furthermore, as a comparison of Figs. 4 and 7 shows, this can ensure that water ejected from the impeller 28c cannot directly impact the pump chamber wall 25c, but is always caught by the guide vanes 43c and guided in the aforementioned helical lines.

[0054] Based on the pump 11c, it is clear that the guide vanes 43a of the pump 11a of Figs. 1 to 3 could also be designed in this way with increasing height. Finally, the design of this height is independent of the direction of a front region 44 of the guide vanes 43.

[0055] Figs. 10 to 12 show a fourth pump 11d according to the invention. Four flow guide vanes 36d are formed on a support ring 35d on the inner dome 24d. Each vane has a beginning 38d, an end 39d, and an outer edge 40d extending therebetween, as well as a top side 41d. These vanes again serve to improve the pump's efficiency in terms of throughput.

[0056] Guide vanes 43d are also provided on the pump 11d, although unlike the guide vanes of the pumps 11a to 11c, they are not mounted on the flow guide vanes 36d. As the side view of Fig. 10 shows, the guide vanes 43d always have a distance, albeit a small one, from the flow guide vanes 36d, particularly from their upper surfaces 41d.

[0057] The number of guide vanes 43d is twice that of the flow guide vanes 36d, i.e., eight guide vanes 43d. The guide vanes 43d are each arranged approximately in an intermediate region between two flow guide vanes 36d and in the region of half the length thereof. All guide vanes 43d are identically designed. They have a leading edge 45d, an upper edge 46d, and a rear edge 47d. From the side view of Fig. 10, it can be seen that the upper edges 46d all extend in a plane perpendicular to the axis of rotation of the impeller 28d, similar to the upper edges of the guide vanes 43c in Fig. 7. At the same time, the guide vanes 43d change their height only slightly over their admittedly relatively short course; this height becomes somewhat smaller towards the rear, towards the rear edge 47d. This is because a lower edge 48d is slightly pulled upwards in the longitudinal direction, i.e. towards the inlet 17d.

[0058] The guide vanes 43d have a roughly constant curvature, tapering slightly toward the leading edge 45d and the rear edge 47d. Their leading edges 44d point approximately radially toward the rotational axis of the impeller 28d, similar to the pump 11b in Fig. 7. Their radial distance from the impeller 28d is also relatively small.

[0059] Thus, in this design of the pump 11d with the guide vanes 43d, they are designed so to speak independently and separately from the flow guide vanes 36d. Furthermore, they are very effective in removing air bubbles from the pump chamber 21d. Due to their relatively inclined position compared to the circulating pumped water, it can be seen that they somewhat reduce or impair the pumping efficiency of the pump 11d. However, their effectiveness in venting is very good, with the air being removed very quickly. Furthermore, the short length of the guide vanes 43d somewhat reduces the increased flow resistance.

[0060] Figs. 13 to 15 show another pump 11e that has no flow guide vanes at all. Similar to the guide vanes 43d of pump 11d, eight guide vanes 43e are provided here, which are arranged at the very top of the inner dome 24e below the impeller 28e and radially outside thereof. The guide vanes 43e have front regions 44e with a leading edge 45e that extends very close to the impeller 28a or its impeller outlets 31e. The front regions 44e also point approximately radially toward the axis of rotation of the impeller 28e. The guide vanes 43e have an upper edge 46e adjoining the leading edge 45e, which extends at a significantly greater angle to the axis of rotation of the impeller 28e than in the other embodiments. Likewise, a rear edge 47e extends diagonally outward and almost to the inner dome 24e. These guide vanes 43e can be seen as extending, so to speak, from the pump 11d of Fig.10 to 12, which are intended to fulfill the functions of both a helically rotating flow guide vane and guide vanes running obliquely to the flow direction, i.e., both together. Because the front area 44e, with the leading edge 45e, extends radially and very close to the impeller 28e or its impeller outlets 31e, air bubbles can be captured and removed or transported away very quickly. The overall curved shape and the bending of the guide vanes 43e toward the rear edge 47e into somewhat flatter areas achieve the function of helically rotating or helically rotating flow guide vanes to improve water flow.

Claims

Patent claims 1. A pump, in particular for household appliances such as dishwashers or washing machines, the pump comprising: a pump chamber with an inlet, an outlet, and a pump chamber floor, an impeller for pumping water in the pump chamber, the impeller extending above the pump chamber floor, one or more flow guide vanes radially outside the impeller, which are fixedly arranged and extend helically, at least partially, with a pitch extending in the direction of rotation of the impeller in a direction toward the pump chamber floor, the pump with the impeller being designed to function as a centrifugal pump with central axial suction of the water to be pumped through the inlet and radial outflow of the water to be pumped through the outlet, characterized in that: at least one guide vane is arranged on the at least one flow guide vane,wherein the at least one guide vane is curved and protrudes at least partially from the flow guide vane in the axial direction of the pump., 2. Pump according to claim 1, characterized in that at least one guide vane is arranged on that side of the flow guide vane which points away from the pump chamber floor or which points towards an inlet into the pump chamber.

3. Pump according to claim 1 or 2, characterized in that the at least one guide vane has a front edge which runs substantially parallel to the axis of rotation of the impeller, and / or has an upper edge which runs at an angle between 70° and 110° to the axis of rotation of the impeller, preferably at an angle between 80° and 100° to the axis of rotation of the impeller.

4. Pump according to one of the preceding claims, characterized in that the at least one guide vane has a front edge which is arranged on an end face of a support ring on which the flow guide vane is arranged radially outwardly, wherein preferably the beginning or the frontmost region of the guide vane is on the same end face of the support ring, wherein in particular the flow guide vane begins on a plane in which the end face of the support ring runs.

5. Pump according to one of the preceding claims, characterized in that an upper edge of the guide vane extends at an angle between 2° and 20° to that side of the flow guide vane on which the guide vane is arranged, wherein preferably an axial height of the guide vane remains the same in the direction parallel to the axis of rotation of the impeller.

6. Pump according to one of claims 1 to 4, characterized in that an upper edge of the guide vane runs at an angle between 80° and 90° to the axis of rotation of the impeller such that an axial height of the guide vane increases in the direction parallel to the axis of rotation of the impeller, wherein preferably the upper edge of the guide vane runs at right angles to the axis of rotation of the impeller.

7. Pump according to one of the preceding claims, characterized in that the at least one guide vane does not run exactly along a circular path around a rotational axis of the impeller, but a front edge of the guide vane has a smaller radial distance from the rotational axis of the impeller than the subsequent part of the guide vane up to a rear edge, wherein preferably a radial distance of the guide vane from the rotational axis of the impeller becomes greater from the front edge to the rear edge.

8. Pump according to one of the preceding claims, characterized in that the at least one guide vane along the helical course of the flow guide vane has 70% to 110% of its length, preferably 80% to 100% of its length.

9. Pump according to one of the preceding claims, characterized in that a front edge of the at least one guide vane has a distance of not more than 10% of the length of the flow guide vane from a front region of the flow guide vane, preferably a distance of not more than 5%.

10. Pump according to one of the preceding claims, characterized in that a front region of the guide vane adjoins a front edge of the at least one guide vane, the front edge and the front region pointing in the radial direction towards the axis of rotation of the impeller.

11. Pump according to one of claims 1 to 9, characterized in that a front region of the guide vane adjoins a front edge of the at least one guide vane, the front edge and the front region pointing in the circumferential direction and in the tangential direction, respectively.

12. Pump according to one of the preceding claims, characterized in that a guide vane is arranged in a central region of the flow guide vane, wherein preferably a length of the guide vane is between 10% and 30% of a length of the flow guide vane, wherein in particular a front edge of the guide vane is arranged on an end face of a support ring, on which the flow guide vane is arranged radially outward, with a smaller radial distance to the axis of rotation of the impeller than the flow guide vane.

13. Pump, in particular for household appliances such as dishwashers or washing machines, the pump comprising: a pump chamber with an inlet, with an outlet and with a pump chamber base, an impeller for conveying water in the pump chamber, the impeller running above the pump chamber base, a circumferential support ring between the impeller and the pump chamber base, the support ring being arranged substantially below the impeller, the pump with the impeller being designed to function as a centrifugal pump with central axial suction of the water to be conveyed through the inlet and radial outflow of the water to be conveyed through the outlet, characterized in that: at least two curved guide vanes are arranged on the support ring, the guide vanes run from a respective front edge with increasingly greater radial distance to a rotation axis of the impeller.

14. Pump according to claim 13, characterized in that all guide vanes are of the same design.

15. Pump according to claim 13 or 14, characterized in that the at least two guide vanes are bent or curved in two directions, preferably each bent or curved away from the axis of rotation of the impeller.

16. Pump according to one of claims 13 to 15, characterized in that 6 to 10 guide vanes are arranged on the support ring, preferably are evenly distributed and are arranged in the same way on the support ring.

17. Pump according to one of the preceding claims, characterized in that the guide vanes do not overlap each other in the direction of rotation around the impeller or the guide vanes are spaced apart from each other in the direction of rotation, wherein preferably all the guide vanes are arranged in a uniformly distributed manner.

18. Pump according to one of the preceding claims, characterized in that the at least one guide vane, preferably all guide vanes, are arranged at least partially at the axial height and radially outside an outlet from the impeller, wherein preferably a part of the guide vane is arranged below the impeller towards the pump chamber floor, in particular the larger part of the guide vane.

19. Household appliance, preferably a dishwasher or washing machine, with a pump according to one of the preceding claims, characterized in that the household appliance has a treatment chamber with a chamber outlet therefrom, the pump being arranged behind the chamber outlet.

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