EP2638296B1 - Pump - Google Patents

Description

Field of application and state of the art

The invention relates to a pump, in particular a liquid pump, which has a rotor or impeller in a pump housing.

From the EP 1 201 933 B1 a fluid pump is known, which has a pump housing with a rotor or impeller therein. On an outer wall of the pump chamber or the pump housing, a heating element is provided.

The WO 2010/034488 A1 describes a further liquid pump with a rotor or impeller in a pump housing. Here, a heating element may be provided in a pump chamber of the pump housing, alternatively also on the outside of a pump chamber wall. The rotor has a central and in the axial direction directed to him inlet. An outlet from the pump housing is provided on the outside of the edge of the pump chamber wall in the radial direction.

The EP 2 221 485 A2 describes a liquid pump with an impeller in a pump housing. On the pump bottom, a rib for influencing the shape of a pump chamber and the hydraulic properties of the pump is provided radially outside the impeller.

From the DE 10 2007 017 271 A1 For example, a pump with a pump housing and an impeller is known therein. Outside of a pump chamber wall heating is arranged. Vanes are provided in a pump chamber above and outside the impeller around an inlet to the pump.

Task and solution

The invention has for its object to provide an aforementioned pump, can be avoided with the problems of the prior art and in particular a very efficient working and easy to manufacture 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 further claims and are explained in more detail below. The wording of the claims is incorporated herein by express reference.

It is provided that the pump housing has a pump chamber with a pump bottom, a pump chamber wall and a lid thereon. The rotor rotates over the bottom of the pump, advantageously at a short distance. The pump chamber wall extends around the outside of the rotor, advantageously with a certain distance to it. An inlet to the rotor or the pump chamber is provided centrally and in the axial direction of the rotor. An outlet from the pump housing or the pump chamber is provided on the outside of the edge of the pump housing or the pump chamber wall.

According to the invention, the pump chamber wall has a heating and guide elements are provided on the pump bottom, which are arranged radially outside the rotor, thus surrounding it. The advantage of these guide elements is that they direct the liquid flow in the pump particularly well, especially towards a pump chamber wall, which is heated by the heating. Thus, an optimized entry of the heat from the heating takes place in the pumped liquid. The guide elements can cause the number of revolutions or revolutions of the water at the pump chamber wall and thus along the heating is increased or an additional Rotation of the water in the pump takes place along the heated pump chamber wall. Due to the flat and so to speak transition minimized flow of the pump chamber wall, a stall can be avoided, the angle should be as flat as possible or pointed by design of the guide elements. The liquid flow advantageously runs along the pump chamber wall to the outlet.

Advantageously, the guide elements are not only provided on the pump bottom, but even arranged or attached thereto. Advantageously, the pump bottom can be formed integrally and integrally with the guide elements thereto. Here is a production in a piece of plastic offers. Thus, although the production of the pump bottom is somewhat more expensive, but it can account for a further assembly step for the guide elements. Furthermore, the position of the guide elements to the rotor, which can also be mounted on the pump floor or at least with respect thereto, improved or executed more accurately. This can increase the effectiveness of the pump. Another advantage of such guide elements is in addition to the increased efficiency or heating effect of the pump also in that due to a better-managed flow noise in the pump can be reduced.

In the invention, the guide elements are formed curved in the radial direction. They can be bent or bent in the direction of rotation of the rotor. They have the form of so-called vanes for a particularly favorable guidance of the liquid flow.

In an embodiment of the invention, it is advantageous if the guide elements extend to just before the pump chamber wall. Thus, virtually the influx of the inside of the pump chamber wall is as targeted as possible. A distance of a few millimeters to an inch or two may be sufficient. To inside to the guide elements also approach relatively close to the rotor or impeller. A distance can be here a few millimeters.

Advantageously, the rotor can be recessed a little further into the pump bottom than lower and radially inward areas of the guide elements. This can in particular apply to a rotor lower part, so that rotor blades extending on the rotor lower part are quasi-continuously continued in their course by the guide elements. This continuation of the course applies both to a bend along the direction of rotation of the rotor and another bend. This can namely Also be present such that both rotor blades and vanes from a certain point of the pump bottom with curved or curved course away. Up to this point, the rotor blades may be curved downwardly from a central rotor area to the pump floor.

In one embodiment of the invention can be provided that the pump chamber with the lid on top of it or its closure is pulled up to close to the rotor, ie in the direction of the pump bottom. The lid is the area of the pump which limits the pump chamber upwards around the inlet or lies inside the pump chamber wall. It may even be provided that the cover is partially below the uppermost portion of the rotor, preferably in the rotor central region, so that the lid follows with its shape somewhat the course of the rotor. Outwardly to the lid then goes away from the rotor and rises far above this or the pump bottom in the direction of the pump chamber wall. This bending of the lid away from the rotor can advantageously take place approximately at the outer diameter of the rotor. Thus, the lid rises again above the guide elements and releases a certain space over them, which the liquid flow can use to flow along the pump chamber wall.

There may be provided about three to twenty such baffles on the pump. Advantageously, there are six to eight vanes. It is possible to provide as many rotor blades as guiding elements. However, this does not have to be the case; in particular, it may also be more vanes than rotor vanes.

In a further embodiment of the invention, the outlet of the pump chamber can be arranged radially on the outside of the pump chamber. It can be formed by a progressively rising upward of the pump bottom away course of the pump chamber. The pump chamber runs here in the upper area annular, since radially inwardly so the obliquely upwardly drawn cover of the pump chamber runs. The outlet can lead out of the pump chamber in the direction of rotation or circumferential direction, as a kind of tangential discharge of the liquid.

Advantageously, the pump chamber wall with the heating element is integrally formed thereon or in one piece. If here a shock odgl. can be avoided in the circumferential direction, the liquid can flow along a smooth surface and there is not so much turbulence. For this purpose, although the heat transfer is somewhat deteriorated compared to a fluidized fluid flow. However, this can easily be compensated by the fact that just the guide elements cause an additional rotation of the liquid flow along the heated Pumpenkammerwandung so that a corresponding heat loss or heating of the liquid can take place.

Brief description of the drawings

Fig. 1

einen Schnitt durch eine erfindungsgemäße Pumpe,

Fig. 2

eine schräge Draufsicht auf eine teilweise zerlegte Pumpe bzw. eine Sicht in deren Gehäuse und

Fig. 3

eine Draufsicht auf die Darstellung gemäß Fig. 2.

An embodiment of the invention is shown schematically in the drawings and will be explained in more detail below. In the drawings show:

Fig. 1

a section through a pump according to the invention,

Fig. 2

an oblique plan view of a partially disassembled pump or a view in the housing and

Fig. 3

a plan view of the illustration according to Fig. 2 ,

Detailed description of the embodiment

In Fig. 1 a pump 11 is shown, which can be used as a liquid pump particularly well for a dishwasher or a washing machine. The pump 11 has a pump housing 12, whose course can be seen through the quasi-check hatching. It can be seen that in or on a housing bottom 13, a motor 14 for driving the pump 11 is arranged.

A cover 15 of the pump housing 12 is formed with a going from the outside inward recess 15 'downwards, which has circumferentially approximately the same distance from the housing bottom 13. Within the recess 15 'is an inlet pipe 16, which is integrally formed on the lid 15. It is located exactly centrally above the dot-dash line shown central longitudinal axis of the pump 11, on which also a rotation axis of the motor 14 is located.

Housing bottom 13 and cover 15 are connected to one another with a side wall 17 or these three parts form the pump housing 12 substantially. As can be seen, without being explained in more detail, the side wall 17 is sealed by means of a plurality of seals 18 on the housing bottom 13 and cover 15 at.

The side wall 17 is formed here as a heating element. For this purpose, it advantageously consists of a carrier material such as metal, in particular stainless steel, under certain circumstances alternatively made of temperature-resistant plastic. On this substrate, a heating element is applied in a flat manner, which may be as usual and with an insulating layer can be done underneath. This is advantageously done on the outside, which facilitates electrical connection and reduces insulation problems. The heating elements can be advantageously applied in thick-film technology, which is basically known to the person skilled in the art and therefore will not be explained in detail here.

Just above the housing bottom 13, an impeller 20 is mounted as a rotor on a shaft of the motor 14, whose shape is also known per se. It has impeller blades 21, which in the sectional view in Fig. 1 can be seen less well, so on the oblique view of the Fig. 2 is referenced.

With regard to the design of the lid, it should be noted that its upper edge gradually rises in the circumferential direction up to the elevation 15 ", which then merges into an outlet pipe 19, as is basically also known from such impeller pumps.

About two outer connector 22, the three parts of the pump housing 12 are held together. As shown in the FIGS. 2 and 3 four such connectors 22 are provided.

On the upper side of the housing bottom 13, which consists of plastic, a plurality of guide elements 24 are provided. As seen from the right guide element 24 in a sectional view in Fig. 1 can be seen, the seven guide elements 24 are integrally formed on the housing bottom 13, in particular with molded. This is not a problem in a plastic production. The elongated and curved or curved shape of the guide elements 24 is made of FIGS. 2 and 3 also easy to recognize. They extend inwards to just below the impeller 20 and outwardly they have some distance from the side wall 17, for example, a few millimeters. It is striking that seven guide elements 24 are provided and five impeller blades 21. These are shown in dashed lines in the plan view. In addition, the shows Fig. 3 that the curvature the impeller blades 21 is reversed to the curvature of the guide elements 24. But this is also known in principle for the expert.

Furthermore, how are out Fig. 1 and 2 It can be seen, the guide elements 24 are formed so that they have in the area to the impeller 20 out approximately its height or exceed the height of the impeller blades 21 something. The height of the guide vanes may also vary in the course of the flight, it may, for example, decrease towards the outside and in some circumstances even become zero.

From the Fig. 1 can still be seen that the housing bottom 13 in the region in which the guide elements 24 sit thereon or are molded, is pulled outwards to the outside, that is pulled up outside the impeller 20. As a result, a movement of the pumped with the pump 11 water upwards is favored or effected. The pumped water performs several revolutions in the interior of the pump housing 12, before it is promoted so far that it leaves through the increase 15 'and the outlet pipe 19, the pump 11 again. A kind of baffle helps to move the water upwards. However, it does not contribute to the number of water revolutions. It is from the Fig. 1 also to recognize that the interior of the pump housing actually forms a substantially annular volume. In particular, in this form of the pump housing 12 or an interior, it should be noted that the ratio between volume and area of the side wall 17 is relatively small, that is, that the side wall 17 is relatively large in comparison to the volume. This can be seen almost at the distance between the side wall 17 and the lid 15 above the recess 15 'of the lid. If the entire pump housing 12 is filled with water to be conveyed, a volume of water flowing along the side wall 17 can be heated very well by its heating element function. The fact that the subsidized Water just makes several revolutions in the pump housing 12, as explained above, this effect still improves.

For movement or guidance of the water just said guide elements 24 are of great importance. They additionally set the water in rotation and direct it to the side wall 17 in the flat angle mentioned at the beginning. This results in a very good and fast applied flow. With the impeller 20 or its Impellerschaufeln 21 alone, this is hardly so easy to reach.

The further inventive advantage of the preferred integral molding of the guide elements 24 on the housing bottom 13 is in the easier manufacturability, namely because the housing bottom 13 can be made as a whole plastic injection molded part. As a result, the guide elements 24 are mounted much more stable on the housing bottom 13. Furthermore, they can odgl with soft transitions and no column. be provided on the housing bottom 13, so that here the liquid flow can be conducted as well as possible and to the desired extent. Characterized in that the impeller 20 according to Fig. 1 is sunk slightly deeper into the housing bottom 13, it can be achieved that radially outside of the housing bottom 13 is guided exactly in the lower regions of the impeller blades 21 to the outside. Even so, the liquid flow can be performed as advantageous as possible.

The side wall 17 can, as from the FIGS. 2 and 3 can be seen to be formed as a closed circular ring, ie without impact odgl .. Either they can consist of a seamless tube or be cut off from a longer such tube. Alternatively, it may be bent from a sheet metal strip whose end edge are connected in shock, but just smooth or so that the shock is subsequently closed and smoothed. The subsequent application of the heater on it is not a problem, especially because thick-film heating on arched surfaces can be applied by appropriate printing process.

Claims (10)

1. A pump (1), in particular a liquid pump, including a rotor or an impeller (20) in a pump housing (12) which comprises a pump chamber, a pump bottom (13), a pump chamber wall (17) as well as a cover (15), wherein the rotor rotates above a pump bottom at a small distance thereto, wherein the pump chamber wall is provided around the rotor exterior, wherein an inlet to the rotor is provided centrally and in axial direction towards the rotor and an outlet (19) from the pump housing is provided on the outer periphery of the pump chamber wall, wherein guide elements (24) are provided at the pump bottom, which are arranged radially outside the impeller, characterized in that a heating means is provided on the pump chamber wall, and in that the guide elements extend as guide blades in a curved manner in radial direction.
2. The pump according to claim 1, characterized in that the pump bottom is configured integrally and in one piece with the guide elements thereon, preferably made of plastic.
3. The pump according to claim 1 or 2, characterized in that the guide elements are configured such that the liquid flow after exiting the rotor impacts the pump chamber wall at an acute angle, und preferably streams further along the pump chamber wall up to the outlet.
4. The pump according to any of the preceding claims, characterized in that the guide elements are bent or bent-off into the rotation direction of the rotor.
5. The pump according to any of the preceding claims, characterized in that the guide elements extend almost as far as up to the pump chamber wall.
6. The pump according to any of the preceding claims, characterized in that the rotor is slightly more embedded into the pump bottom than lower parts of the guide elements, wherein preferably rotor blades of the rotor in the course thereof have a steady continuation in the guide elements, in particular also with a bend and/or a curved form away from the pump bottom.
7. The pump according to any of the preceding claims, characterized in that the pump chamber with the cover on top extends almost up to the rotor or to an upper side of the rotor facing the inlet, wherein preferably the cover is configured as upper boundary of the pump chamber around the inlet radially outside the rotor extending away again from said rotor outwards, wherein said region is above the guide elements.
8. The pump according to any of the preceding claims, characterized in that 3 to 20 of such guide elements are provided, in particular 6 to 8, wherein preferably as much guide elements as blades on the rotor or impeller, respectively, are provided.
9. The pump according to any of the preceding claims, characterized in that the outlet from the pump chamber is arranged radially outside on the pump chamber and in particular is configured as a course ascending more and more upwards away from the pump bottom of the pump chamber having a ring shape in this upper region, wherein preferably the outlet leads out of the pump chamber in radial direction.
10. The pump according to any of the preceding claims, characterized in that the pump chamber wall is configured integrally or in one piece with the heating element thereon and without a joint or the like in the circumferential direction.

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