EP2495444A2 - Pump - Google Patents

Abstract

The pump (11) has an impeller (19) for conveying fluid or water, which rotates in a pump chamber (13) with a pump base. One or multiple stationary flow guide blades (25a,25b) are arranged radially outside the impeller, which extend helically with an incline away from the pump base, where the incline extends in the rotational direction of the impeller. One of the flow guide blade extends up to the lower side of the impeller.

Description

Field of application and state of the art

The invention relates to a pump, such as is used in particular in household appliances such as a dishwasher or washing machine, wherein the pump has an impeller for conveying fluid or water.

A corresponding pump is from the EP 2150165 A2 known, to which expressly referred. It illustrates both in principle and practically very well the basic operation of such a pump or centrifugal pump with impeller. The problem with this pump is that in some cases it has been observed that when air is partially drawn in with the fluid or water, air bubbles are rotated in a circle by the impeller. These air bubbles often do not come off the pump or can not always be removed from the pump chamber, forming a kind of swirling circulating hose. Of course, they affect the pumping power very negative.

Task and solution

The invention has for its object to provide an aforementioned pump, can be avoided with the disadvantages of the prior art and in particular a practical and störunanfällige pump can be created.

This object is achieved by a pump with the features of claim 1. Advantageous and preferred embodiments of the invention are the subject of the further claims and will be hereinafter explained in more detail. The wording of the claims is incorporated herein by express reference.

It is envisaged that the centrifugal pump with the impeller to be pumped fluid or water sucks centrally and in the axial direction and radially flows out or out of the impeller. Then the fluid to be pumped circulates in the pump chamber until it flows out again approximately in the radial direction from the pump chamber and the entire pump. The impeller extends with a bottom over a pump bottom, below which is often the drive motor, sitting on the axis of the impeller.

According to the invention, one or more flow guide vanes are arranged radially outside the impeller and extend helically away from the pump bottom in the direction of rotation of the impeller. At least one flow guide blade extends as far as the underside of the impeller or close to it, advantageously with a maximum of 5 mm spacing, particularly advantageously with a maximum of 3 mm or even only 1 mm. A Strömungsleitschaufel or especially exactly downwardly reaching Strömungsleitschaufel can cause circulating fluid and in particular the above-described circulating hose made of water with a variety of air bubbles is tapped virtually at the bottom of the impeller at the bottom of the pump and by the slope in the direction of rotation Impellers away from the pump bottom and to the outlet from the pump is promoted. While the additional flow guide vanes conveying water without air inclusions only slightly affect or improve the performance of the pump, above all the described venting effect is very advantageous and very pronounced. Multiple airfoils may extend downwardly for tapping and conveying out air bladder fluid. In practice, however, it has been found that even a single flow vane shows good effect and may already be sufficient.

In an advantageous embodiment of the invention, the at least one downwardly drawn Strömungsleitschaufel not only extends to the bottom of the impeller, but even at least until just before the bottom of the pump, advantageously with a maximum distance of 5 mm, more preferably at most 3 mm or even only 1 mm , Under certain circumstances, it can even reach up to the bottom of the pump and rest elastically. Then the mentioned tapping effect is maximal.

The Strömungsleitschaufeln are advantageous fixed or are fixedly arranged in the pump chamber, while the impeller rotates yes. Of course, this does not exclude that the flow vanes can also be taken out of the pump chamber or can be mounted as a separate part by inserting.

The at least one flow vane is advantageously provided on a circumferential support ring, which extends substantially radially outside of an upper region of the impeller, in such a way that it does not interfere with the outflow of the fluid to be delivered from the impeller in the radial direction. The advantage of such a support ring with flow vane on it is that only a single part must be made and used in the pump chamber and fixed therein. At the said point in the upper part of the impeller, the support ring does not interfere. The above-described, at least one up to the bottom of the impeller or to the pump bottom protruding Strömungsleitschaufel can then protrude in the axial direction on the support ring. Although this means that it must be self-supporting and not attached to the support ring and placed by this. However, this is not a problem due to the correspondingly stable design of the flow guide vane.

As previously described, it is actually sufficient if a single flow vane up to the bottom of the impeller or to the bottom of the pump is sufficient, although a total of several can be provided, it is considered sufficient if only this one flow vane protrudes beyond the support ring and protrudes from this.

In a single flow vane can also be dispensed with the support ring when it runs more than 180 ° around the impeller and can be kept stable position. Advantageously, it has a complete revolution around the impeller.

As stated above, in practice, two or a maximum of three flow vanes are considered sufficient. With more than one flow vane it can handle less than 180 ° around the impeller. Preferably, it is less than 160 °, but more than 90 °. This is especially true for a flow vane that extends to the bottom of the impeller or just before or to the bottom of the pump. Another Strömungsleitschaufel, which is provided only on the aforementioned support ring, can rotate about 90 ° or slightly less.

In a further embodiment of the invention, it is considered advantageous if the at least one flow vane in the course of the pump bottom away has an increasingly steeper rising angle. This causes the troublesome hose to be conveyed fluid and circulating water bubbles is removed at a rather shallow angle from the pump bottom and then the entire fluid flow is increasingly directed in the axial direction. Once this has taken place in part, the feeding out can be accelerated or increased by an increasingly steeper angle. It can be provided that in a circulation of a flow vane of about 90 ° around the support ring around its entire axial extent is covered, ie from a lower edge to an upper edge.

An angle which increases in the direction of rotation of the flow guide vane also has the advantage that the velocity component increases in the axial direction, that is to say also towards the outlet out of the pump. This improves the delivery effect from the pump.

In a further development of the invention can be provided that the impeller is closed on its underside or on its upper side. At the top can be advantageously provided an upper cover.

The above-described support ring for the at least one flow vane does not cover a lateral radial outlet of the impeller between the upper cover and the underside. Here is only the reaching to the bottom of the impeller or shortly before the pump bottom Strömungsschschel. There, as well as the aforementioned EP 2150165 A2 describes that the impeller is usually hat-like pulled up at its top with the top cover, this area is enough to provide or attach the support ring.

In a further embodiment of the invention, a pump bottom region can be pulled radially outward of the impeller, ie away from the pump bottom or the motor located underneath, and thereby have an oblique course with increasing radial distance from the impeller. The running up to the underside of the impeller Strömungsleitschaufel can then run with a small distance to the sloping pump floor area or even advantageously abut it. By elastic concerns quasi a gapless transition can be created for an improved removal of the air bubbles.

In a further embodiment of the invention, a free inflow section of the reaching to the bottom of the impeller Strömungsleitschaufel, which just reaches down to be tapered or tapered. A Tapering or tapering may be approximately uniform and ranging from a maximum width at the base of an abovementioned support ring until just at the tip at the free end of the Anströmabschnitts near the bottom of the impeller or on the pump floor fitting.

Thus, it is possible that virtually with some radial distance from the impeller, the Strömungsleitschaufel or her Anströmabschnitt over a large part of the cross section of the pump chamber radially outside the impeller on the pump bottom or the wall is applied. As a result, the best possible removal of air bubbles is possible or there are no undercuts or other spaces where the air bubbles can settle.

In an advantageous embodiment of the invention can be provided that the projecting beyond the support ring Strömungsleitschaufel that extends to the bottom of the impeller or is applied to the pump floor, is formed elastically. This can be with a certain spring load. For this purpose, the above-described inflow section is particularly suitable.

In an advantageous embodiment of the invention can be provided that extends a Strömungsleitschaufel not only to the pump bottom through the support ring for best possible tapping of air bubbles, but also extends in the other axial direction. For this purpose, a free-standing discharge section can be provided which, for example, leads the fluid to be conveyed or a mixture of fluid and air bubbles to be conveyed directly to an outlet from the pump chamber. Thus it can also be specified how often the fluid to be pumped circulates in the pump chamber before it flows out of the pump.

In an advantageous embodiment of the invention, the flow guide vane can be designed so that it only halfway to an outer wall of the pump chamber filled by the fluid to be delivered ranges. This can ensure that the desired through the flow vane conveying effect is achieved. If the outer chamber wall is heated, this heating effect is not impaired. After radially inward, the at least one flow guide blade extends outside of the impeller. Slightly above it, the flow vane runs on the support ring. So that this does not unnecessarily reduce the pump chamber, it should run as close as possible to an inner wall of the pump chamber or rest against it. This inner wall usually consists of a pipe section, on the one hand forms the central axial intake for the fluid to be pumped and therefore runs close to the top of the impeller, then slightly expands and almost inverted outwards and reverses the direction and then back to the pump cover or runs to the pump chamber top. Furthermore, in the event that the pump has said heating on the outside of the pump chamber, its effect remains as unimpaired as possible. The support ring thus disturbs neither the flow of water at the heating nor does it otherwise reduce their effect.

These and other features will become apparent from the claims and from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into individual sections as well as intermediate headings does not restrict the general validity of the statements made thereunder.

Brief description of the drawings

Fig. 1

einen seitlichen Längsschnitt durch eine erfindungsgemäße Pumpe,

Fig. 2

eine Schrägansicht eines Tragrings mit zwei Strömungsleitschaufeln daran und dem zugehörigen Impeller entsprechend Fig. 1,

Fig. 3

die Ansicht auf den Tragring aus Fig. 2 mit den Strömungsleitschaufeln ohne Impeller,

Fig. 4

eine Draufsicht auf die Anordnung aus Fig. 2,

Fig. 5

eine Seitenansicht auf die Anordnung aus Fig. 2 und

Fig. 6

eine Abwandlung entsprechend der Darstellung aus Fig. 5 mit einer weiter nach unten gezogenen Strömungsleitschaufel.

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

Fig. 1

a lateral longitudinal section through a pump according to the invention,

Fig. 2

an oblique view of a support ring with two flow guide vanes and the associated impeller accordingly Fig. 1 .

Fig. 3

the view on the support ring Fig. 2 with the flow vanes without impeller,

Fig. 4

a plan view of the arrangement Fig. 2 .

Fig. 5

a side view of the arrangement Fig. 2 and

Fig. 6

a modification as shown Fig. 5 with a downwardly drawn flow vane.

Detailed description of the embodiments

In Fig. 1 is a lateral longitudinal section of a pump 11 according to the invention shown with a pump housing 12 in which a pump chamber 13 with an outer chamber wall 14 is located. Such a per se conventional structure of a so-called radial pump is for example from the EP 2150165 A2 known.

On the pump housing 12, a pump bottom is further formed with an inner pump bottom 15a and an outer pump bottom 15b and a central axial tubular inlet 16, which merges into a pump cover 17. This in turn merges into an inner wall which leads to a lateral outlet 18.

The inlet 16 leads to an over the pump bottom 15 in the usual manner mounted impeller 19. It is as a closed impeller 19 with a lower impeller disk 20, an upper impeller disk 21 and main vanes 23 formed therebetween. In Fig. 1 It can be seen that the impeller 19 extends with its lower impeller disk 20 just above the inner pump bottom 15a and here a gap 24 of a few mm is given. This gap 24 serves to compensate for the axial play of the impeller 19 mounted on a shaft of a pump motor.

Between inner pump bottom 15 a and outer pump bottom 15 b, a step is arranged, which is almost just outside the lower impeller disc 20. It can be seen that the outer pump bottom 15b approximately simulates the curvature or curvature of the lower impeller disk 20. This serves for improved fluid flow.

To convey fluid in the pump 11, the impeller 19 rotates clockwise in the longitudinal direction as seen from the left and delivers fluid into the pumping chamber 13 radially and with a velocity component in the circumferential direction. The chamber wall 14 is formed or heated in a manner not shown as a heating element, so that the flowing along its inner side fluid on the way to the outlet 18 with several revolutions flows along it and is heated. Also this is on the aforementioned EP 2150165 A2 directed.

Around the cylindrical portion of the pump cover 17 extends radially outside and at the level of the upper impeller disc 21, a support ring 29. It can be pushed onto the pump cover 17 with press-fit for fixing, alternatively, it may be snapped or glued. He is in the axial direction only slightly to the right on the pump cover 17 via. As compared to the following Fig. 2 to 5 becomes clear, 29 two flow vanes 25a and 25b are arranged or formed on the outside of the support ring. Of the flow guide vane 25a is shown substantially only their projecting portion and the free lower end 26a, which corresponds to the above inflow section. The flow vane 25a lies with the projecting region substantially at the outer pump bottom 15b to its free end 26a, which is here half hidden by the lower impeller disc 20. The other Strömungsleitschaufel 25b is not in the axial direction on the support ring 29 via, as in Fig. 1 can be seen. It can also be seen that the width of the flow guide vane 25b is approximately half the distance between the support ring 29 and the heated chamber wall 14.

Out Fig. 2 is seen in an oblique view, as the flow vanes 25a and 25b are arranged on the outside of the support ring 29 and extend with a recognizable slope. Since the impeller 19 with lower impeller disc 20, upper impeller disc 21 and main vanes 23 therebetween rotates clockwise to the right, as well as in Fig. 4 , the pumped fluid runs in the same direction, especially if the air bubbles mentioned above are in it. Above all, the fluid flow with the air bubbles runs along the outer pump bottom 15b and can be removed there by the adjacent free lower end 26a and lifted off by means of the flow guide vane 25a and conveyed to the outlet 18 of the pump. The flow guide vane 25b also serves to convey away, so that the fluid flow is also conveyed away from the pump bottom 15b in its region. The Fig. 5 shows this in side view.

In Fig. 3 the impeller 19 is omitted for the sake of clarity. Very well, the shape of the downward over the support ring 29 projecting portion of the flow vane 25a to see the free lower end 26a. Advantageously, the mold is designed such that the flow guide vane 25a rests with the outer edge of the free area on the outer pump bottom 15b.

As seen from the top view Fig. 4 can be seen, is the free lower end 26a of the Strömungsschschaufel 25a including the free portion radially only slightly outside of the impeller 19. So can actually the largest part or even the entire circumferential tube of fluid or water with a plurality of air bubbles are tapped therein. The aforementioned distance of the Strömungsleitschaufel 25a and the free lower end 26a to the bottom of the impeller 19 is about 3 mm or even slightly less.

In the modification of the side view Fig. 5 show the Fig. 6 as a comparison, as with a flow vane 125a on a support ring 129, a lower free end 126a is further pulled down, for example, 1 mm to 20 mm or even more, and even an impeller 119 and a lower impeller 120 dominated. This can be different than in Fig. 1 trained pump bottoms be beneficial. It is also an upper Impellerscheibe 121 and main vanes 123 can be seen, which are the same. The aforementioned distance of the Strömungsleitschaufel 125 to the bottom of the impeller 119 is a few mm, preferably about 3 mm or even slightly less.

Furthermore, shown by dashed lines, as in a second Strömungsleitschaufel 125 b, an upper free end 127 b as the aforementioned Ableitabschnitt in the other direction can protrude freely over the support ring 129 and then, on the Fig. 1 transferred, a further improved guidance of the fluid flow toward the outlet 18 of the pump 11 causes. A protrusion in this direction may be greater or less than the protrusion of the free portion of the other flow vane 125a. However, this essentially depends on the spatial conditions in a pump chamber.

Claims (12)

Pump, in particular for household appliances such as dishwashers, with an impeller for conveying fluid or water, which rotates in a pump chamber with a pump bottom, wherein the pump with the impeller is designed for a function as a centrifugal pump with central axial suction and radial outflow of fluid to be delivered, wherein the impeller extends with its underside above the pump bottom, characterized in that radially outwardly of the impeller one or more fixed Strömungsleitschaufeln are arranged, which extend helically extending in the direction of rotation of the impeller slope away from the pump bottom, wherein at least one Strömungsleitschaufel up reaches the bottom of the impeller. Pump according to claim 1, characterized in that the at least one Strömungsleitschaufel extends to just before the pump bottom, preferably adjacent to the pump bottom with a small gap. Pump according to claim 1 or 2, characterized in that the at least one flow guide vane is provided on a circumferential support ring which extends substantially radially outwardly of an upper portion of the impeller, wherein the at least one projecting up to the underside of the impeller Strömungsleitschaufel in the axial direction over survives the support ring. Pump according to one of the preceding claims, characterized in that exactly a single flow vane protrudes beyond the support ring and extends to the underside of the impeller. Pump according to one of the preceding claims, characterized in that a flow vane less than 180 ° around the impeller, preferably more than 90 ° and less than 160 °. Pump according to one of the preceding claims, characterized in that the at least one Strömungsleitschaufel has in the course of the pump bottom away an increasingly steeper rising angle. Pump according to one of the preceding claims, characterized in that the impeller is closed on its underside and its top, in particular by an upper cover on its upper side, wherein the support ring according to claim 2 does not cover the lateral outlet of the impeller but only up to the Bottom of the impeller reaching flow vane. Pump according to one of the preceding claims, characterized in that a pump bottom region is drawn radially outwardly of the impeller with an oblique course and at a radial distance from the impeller, wherein the extending up to the underside of the impeller Strömungsleitschaufel runs at a small distance to the oblique pump bottom portion or attached to it. Pump according to one of the preceding claims, characterized in that a free, downwardly reaching inflow section of the reaching to the bottom of the impeller Strömungsleitschaufel is tapered, in particular with approximately uniform taper from a maximum width at the neck on a support ring to a peak on free end of the inflow section near the bottom of the pump or the bottom of the impeller. Pump according to one of the preceding claims, characterized in that the reaching to the bottom of the impeller Strömungsleitschaufel is elastic and spring force loaded on the pump floor, in particular with the Anströmabschnitt according to claim 9. Pump according to one of the preceding claims, characterized in that a Strömungsleitschaufel projecting in the direction of the pump bottom away over the support ring and extending therefrom extends according to their previous course and the support ring, preferably with a freestanding discharge. Pump according to one of the preceding claims, characterized in that a Strömungsleitschaufel reaches close to an outlet of the pump, preferably the Strömungsleitschaufel according to claim 11 with the Ableitabschnitt.

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