EP2275017A2 - Dishwasher with a circulating pump - Google Patents

Abstract

The dishwasher has a washing space for accommodating items to be cleaned, where water is supplied to the space by a circulating pump (6). The pump includes a fixed, central suction channel (11) running up to a rotatable wheel (7) i.e. impeller wheel, where the suction channel is bounded by a tube portion (12). A sliding portion (13) and a thrust ring (14) form a bearing for the wheel. The sliding portion and the ring in a dual function form a sealing system against backflow of water into the channel. The sliding portion and/or the ring is/are formed with a Teflon(RTM: PTFE) coating.

Description

The invention relates to a dishwasher, in particular a domestic dishwasher, with a washing compartment for receiving dishes, cutlery or similar objects to be cleaned, wherein the washing compartment via at least one circulating pump water is supplied and wherein the circulating pump comprises a fixed, centrally on a rotatable impeller inlet channel , according to the preamble of claim 1.

It is known to assign a washing compartment of the washing container of a dishwasher for the introduction of optionally provided with detergent and / or other additives water at least one circulating pump, which is provided with a rapidly rotating during operation impeller, on the axis of rotation centrally an intake passage tapers, the Water radially outwardly promotes away in at least one discharge channel. Since backflow of water from the pressure side to the suction side in an edge gap between the impeller and the housing of the circulation pump due to the pressure difference generated by the impeller is unavoidable, it may cause disturbances and hydraulic detachments in the main water flow. The efficiency of such a pump is considerably reduced. Nevertheless, the marginal gap through which the backflow takes place, can not be arbitrarily reduced, otherwise it could come to a contact between the rapidly rotating impeller and a fixed housing part. This is even more so, as in the operation of such a pump forcibly the impeller is subjected to an axial force in the direction of the intake passage, since a negative pressure is generated in front of the radial or centrifugal pump. Therefore, for the rotary impeller usually provides an axially retaining bearing on the axis or shaft of its rotation, which is complicated and expensive.

The DE 20 2005 020 138 U1 proposes to improve the seal and thus reduce the backflow before firmly provide a thrust washer on the impeller and there in addition to keep a sliding ring so movable that it is pulled axially against the run-up ring during operation. However, the mounting of such a sliding ring is problematic, in particular, since in the case of impellers produced by injection molding, large tolerances occur and thus the axial travel available for the sliding ring varies. The requirements for the exact axial bearing of the impeller are thus rather increased.

The EP 0 221 300 A1 proposes to provide on one side of the housing angular split rings on the outer edges and the inner edges of wings of the impeller facing the steps of the housing. This, however, results in increased wear of the impeller areas sliding along the angular gap rings. These are also far radially outward, so that there is a very high peripheral speed, which increases the wear even more.

The invention is based on the problem to provide an efficient and inexpensive pump.

The invention solves this problem by a dishwasher with the features of claim 1. Further advantages and features of the invention and its developments are specified in claims 2 to 11.

With the construction according to the invention, the impeller is mounted at its radially inner region, in particular its hub, opposite the intake channel and not only sealed. Due to the fact that one or more reinforced sliding regions or thrust rings are assigned to both the impeller and the pipe region delimiting the intake duct or a separate sleeve, the wear between their contact zones is not increased inadmissibly. The radially far inward position of the one or more sliding regions, in particular on the suction-side end edge of the radially inner hub of the impeller, is also favorable insofar as the peripheral speeds are low there, which further reduces wear and the large tolerances, in particular itself affect the far outward wings of the impeller, makes independent. In addition to the storage function for the impeller of the sliding portion of the impeller and the stop ring form in their expiration successive in a double function and a sealing system against return of water in the intake and thereby increase the efficiency of the pump significantly.

In particular, the sliding region on the suction-side edge, preferably on the suction-side end, the radially inner hub of the impeller, preferably the Ansaugmunds, or at its centrally arranged, against the suction direction of the pump protruding cover plate is provided. Around this centrally arranged hub of the impeller are arranged distributed in the circumferential direction a plurality of blades or blades, in particular integrally formed. These extend radially outward and, viewed in the suction direction of the impeller, have a, in particular convex, bend or Curvature up. In particular, the respective wing is composed of an inner, substantially three-dimensionally bent, curved section and an outer, essentially two-dimensionally bent, curved section. It may be provided on the suction side and / or pressure side, if necessary, a cover plate on the hub of the impeller.

Due to the stable axial bearing thus formed, it is also possible in particular to dispense with a further axial bearing of the impeller, in particular also its drive shaft, completely, so that components are saved and production costs are reduced.

Additionally or alternatively, the sliding region of the impeller and the housing-fixed thrust ring can form not only an axial but also a radial bearing for the impeller, for example by being angled.

In this case, the sliding region and / or the thrust ring can be formed by, in particular separate, annular bodies by means of the impeller or the intake channel, so that they can also have an optimized surface hardness and structure for forming a water sliding film, for example through grooves. Also, an exchange of these parts may possibly be possible.

Alternatively, the sliding region and / or the thrust ring are formed by at least one reinforcement incorporated in the impeller or the suction channel, such as coal particles. For example, such an integral sliding region can also be injection-molded or molded onto the impeller and / or a pipe region delimiting the intake duct by a 2K method, so that the number of components and the assembly effort are minimized. A slip-reducing coating, such as e.g. z. B. by Teflon, is possible in both cases. Optionally, the sliding region on the suction-side end edge of the impeller and the contact region of the stop ring facing this end edge can be provided merely with a sliding-reducing, abrasion-resistant coating.

Further advantages and features will become apparent from the drawing illustrated and described below embodiments of the subject invention.

Fig. 1

eine schematische, perspektivische Ansicht einer Geschirrspülmaschine in einer möglichen erfindungsgemäßen Ausbildung,

Fig. 2

eine teilweise aufgeschnittene Ansicht einer typischen Umwälzpumpe gemäß dem Stand der Technik,

Fig. 3

eine Detailansicht des Übergangsbereichs zwischen einem Ansaugkanal und einem Laufrad in einer erfindungsgemäßen Ausbildung einer Umwälzpumpe, bei der das Laufrad durch einen Anlaufring und einen Gleitbereich axial gelagert ist,

Fig. 4

eine ähnliche Ansicht wie Fig. 3, jedoch mit einem abgewinkelten Anlaufring zur Ausbildung auch eines radialen Lagers,

Fig. 5

eine ähnliche Ansicht wie Fig. 4, jedoch mit einem Laufrad, das auf einer fest stehenden Achse rotiert, und

Fig. 6

die Anordnung nach Fig. 5 in Vorderansicht.

In the drawing shows:

Fig. 1

a schematic, perspective view of a dishwasher in a possible inventive design,

Fig. 2

a partially cutaway view of a typical circulating pump according to the prior art,

Fig. 3

a detailed view of the transition region between an intake port and an impeller in an inventive design of a circulating pump in which the impeller is axially supported by a stop ring and a sliding portion,

Fig. 4

a similar view as Fig. 3 but with an angled stop ring for the formation of a radial bearing,

Fig. 5

a similar view as Fig. 4 but with an impeller rotating on a fixed axis, and

Fig. 6

the arrangement after Fig. 5 in front view.

A dishwasher according to the invention can form a standalone or a built-in or installable device, such as within a kitchenette.

In the FIG. 1 Dishwasher 1 shown schematically is a domestic dishwasher with a washing container 22, which has a washing compartment 2 for receiving and cleaning of crockery, cutlery, cooking utensils or the like. The flushing chamber 2 is here substantially cuboidal and delimited at five of its six outer surfaces of walls 3 of the washing container 22 and to the front of a door 4, which is hinged here only by way of example in its lower part pivotally mounted on a housing of the dishwasher 1. In the washing compartment 2, one or more rotatable spray arms (not shown) for the distribution of possibly mixed with detergent rinse water and a plurality of receiving baskets 5 may be held. The rinse water can run through recesses in the ground in a circulating system in which at least one circulating pump 6 with a rapidly rotating - typically in the order of 2000 to 3500 revolutions per minute - impeller 7 is arranged.

Due to the hydraulic conditions in a radial pump, an axial force is generated during operation in the direction of its suction mouth, which is received by a thrust bearing. In all known types of pumps this thrust bearing is usually located in the region between the impeller and the rotor of the respective drive device for this pump. Thus, it is always structurally required that the impeller in the intake has a mechanical gap to the pump housing, ie between its Ansaugmund and the inlet pipe of the pump. This gap has a high degree of tolerance and thus generates fluctuating hydraulic losses in the pump via backflow or leakage return and hydraulic detachment. This pump design illustrates the FIG. 2 ,

According to the in FIG. 2 illustrated circulating pump 6s according to the prior art there is the rotatable about the axis 8s impeller 7s against an axle 9s axially mounted on a separate bearing 10s and thereby prevented from axial movement. The circulating pump 6s conveys a rinsing water main stream HS radially outward into at least one discharge channel with the blades of its rotating impeller FIG. 2 has been omitted for clarity. The axial bearing 10s is seated in the axial direction of the axle body 9s or viewed in the suction direction of the pump between the impeller 7s and the rotor 13s of the drive machine. By virtue of this axial holding of the impeller 7s, a relatively large edge gap 12s remains between the impeller 7s and the intake passage 11s, which extends in both the axial and radial directions, as compared to an exit-side mouth region of the intake passage 11s. It typically has an axial extent of two to three millimeters and a radial extent of one to two millimeters. It must not be made substantially smaller, since the impellers 7s often produced by injection molding have a large tolerance up to approximately one millimeter and the tolerances can add up. Nevertheless, contact between the impeller 7s and housing parts in the region of the intake duct 11s must be avoided, although an axial force is produced on the impeller 7s in the direction of the intake duct 11s during operation. As a result of the edge gap 12s, which thus fluctuates greatly in its axial and / or radial extent, backflows NS arise, that is to say undesired secondary flows or hydraulic detachments from the main water flow HS, which lead to fluctuating hydraulic losses.

In FIG. 3 an advantageous embodiment of the inventive construction of a circulating pump 6 is shown, which in turn is provided with an impeller designed as impeller 7. On its axis of rotation 8 leads centrally a suction channel 11, which promotes the pump to be pumped water in the drawing from the left to.

The inlet-side intake channel 11 of the circulation pump 6 is bounded by a pipe region 12. Here, in the exemplary embodiment, this has at its output-side region, which faces the front-side edge or intake mouth of the radially inner hub of the impeller 7, a step or recess 141, into which an all-round closed, i. All around running stop ring 14 is fixed to the pipe section 12 is inserted. On the intake ring 14 largely aligned opposite, suction-side end edge of the centrally disposed hub of the impeller 7, an annular sliding portion 13 is provided. It is there stationary component of the impeller 7. It is there at its the peripheral tube portion 12 of the intake port 11 facing, radially inner and axially facing the intake port 11 end 9 of the body 10, in particular the hub or cover plate of the impeller 7 is arranged. This sliding portion 13 contacts the stop ring 14 and is rotatably mounted on this. In particular, this sliding portion 13 of the impeller 7 is water-film bearing on the thrust ring. Thus, the impeller 7 is so axially mounted relative to the intake passage 11 that during operation of the sliding portion 13 of the impeller 7 on the stop ring 14 of the intake passage 11 is rotatably movable. Preferably, the suction-side edge of the hub of the impeller 7 and the thrust ring 14 contact each other with substantially planar contact surfaces, i. they just lie together. For this purpose, the stop ring 14 has a disk-shaped cross-sectional profile with a central through hole, the inner diameter of which corresponds to the inner diameter of the intake passage 11. The step or indentation for receiving the stop ring 14 in the tube region 12 of the intake channel 14 is formed there so deeply in the radial direction that the stop ring 14 can be largely flush-fitted to the inner wall of the intake channel 14. As a result, impermissible projections in the intake channel, which could lead to an impermissible disruption of the flow conditions, are avoided. The impeller 7 rotates in operation with typically 2000 to 3500 revolutions per minute and promotes the water thereby in an outer annular channel - not shown here - and from there by a radial outlet port back in the direction of the washing compartment 2 of the washing compartment 22 back. Between the intake and the outlet side so creates a pressure difference of typically 200 to 400 mbar. In this case, a negative pressure is generated in the intake passage in front of the impeller 7.

The thrust ring 14 is positioned in the intake passage 11 such that the suction-side end edge of the hub of the impeller 7 is seated on it and thus at this contact area of thrust ring and hub of the edge gap SP between the blades or vanes of the impeller 7 and the tube portion 12 of the intake 11th liquid sealing is closed. Thereby are Backflows NS reliably prevented, so that the hydraulic efficiency of the thus formed pump is improved. At the same time, the thrust ring provides a thrust bearing for the impeller, so that viewed in the suction direction SR of the pump 6 behind the impeller 7 may possibly account for more axial bearings. The thrust ring 14 and the sliding portion 13 thus form by their interaction (axial start-up of the impeller 7 against the stop ring 14) thus in operation an axial bearing for the impeller 7 and at least have almost the same diameter.

In the embodiment shown here, only the stop ring 14 is formed by a relative to the intake passage 11 separate annular body, for example of a ceramic material, a metal or a slide-modified plastic. By contrast, here is the sliding portion 13 by a stored in the impeller 7 reinforcement, such as coal particles, Teflon or the like, and thus an integral part of this component 7. Such an impeller 7, for example, in a 2K spray process or by subsequent injection molding of the front sliding portion 13 are produced. Alternatively or additionally, the sliding region 13 may also be formed by a coating of an abrasion-resistant and low-friction material, which is here applied to the suction-side end face, in particular the suction-side edge zone of the hub of the impeller.

In addition, both sliding regions, namely sliding region 13 and thrust ring 14, could each be designed as separate or both as integrated units. Likewise, a reversal of in FIG. 2 shown conditions possible.

Outside the sliding region 13 and stop ring 14, the impeller 7 and the tube portion 12 may be made of different materials, for example, from a lightweight and cheap to produce plastic, such as a POM (polyoxymethylene) - plastic.

In any case, it is possible for another camp as it is in FIG. 1 is represented by the bearing 10s, is dispensable for exact compliance with the axial position of the impeller 7, so that the assembly is simplified and considerable costs can be saved.

The impeller 7 may be at the beginning of its rotational movement axially on the intake passage 11 to move until the sliding portion 13 rolls on the stop ring 14, or in particular already sit from the beginning on the stop ring 14 such that it has a rolling motion is possible and at the same time provided for a sealing effect. It may be advantageous if at least either the sliding portion 13 and / or the stop ring 14 is provided with grooves on its axially facing surface, penetrate into the water and thereby form a thin lubricating film between the parts 13, 14. The grooves may expediently be designed approximately sickle-shaped and have only a small depth, in particular of typically one tenth of a millimeter. In addition, on the parts 13, 14, a coating with a friction-reducing material, such as Teflon, be provided on their axially facing contact surfaces. The axial movement of the impeller 7 to the intake passage 11 can react to the respective manufacturing tolerance - unlike a fixed thrust bearing - by the path of the axial movement of the impeller 7 until it comes to the contact of the parts 13, 14, each having different sizes is. The invention is thus very insensitive to large manufacturing tolerances.

The axially so pressed on each other part pairing 13, 14 not only forms the mentioned thrust bearing, with the next bearing 10s can be saved, but the thrust ring 14 and facing him, suction side, end face sliding portion 13 of the impeller 7 form in a double function, a sealing system against the return of water through the edge gap SP in the intake passage 11. The invention thus solves the above-mentioned problem of hydraulic interference and detachment by the backflowing short circuit water flow NS (see FIG. 2 ). This sealing system is held by the axially acting force in operation on the impeller 7 also forcibly and without further exertion of force in its sealing function.

As in the alternative embodiment of the circulation pump 6a after FIG. 4 is recognizable, there is in principle similar training to the embodiment of FIG. 3 between the in the body 10, in particular hub NA of the impeller 7 radially far inwardly integrated and rotatable with this sliding portion 13a and the separate, fixed stop ring 14a of the intake 11 creates not only a thrust bearing and an axial sealing system, but the sliding portion 13a and the stop ring 14a also form a radial bearing for the impeller 7 from. For this purpose, the stationary stop ring 14a is stepped, so that it is approximately L-shaped in longitudinal section and not only with an axial, but also with a radially inwardly facing surface in contact with the sliding portion 13a of the impeller 7 and this also to radial movement prevents. Here, too, friction-reducing and abrasion-resistant coatings and / or depressions in the axial and radial contact surfaces of the parts 13a, 14a to form a water film can be advantageous.

In this version, a further radial bearing behind the impeller 7 can be omitted, so that more components can be saved.

In the further embodiment of the FIGS. 5 and 6 the circulating pump 6b is designed so that the impeller 7 rotates about a fixed axis 8. In this case, a hub, in particular a sleeve receptacle 16, sits concentrically fixed on its front end 151. It forms an axle holder for the stationary axle body 8 and at the same time acts as a hub, from which, here three, radially outwardly extending spokes 17, extend outwards, which hold a stop ring 14b on the outside. This stop ring 14b is firmly seated in a cut-out or a step 141 of the pipe region 12 surrounding the intake duct 11 and is arranged concentrically with the hub 16. It is held, for example via a press fit in a groove or a cutout 141 of the tube portion 12. On the one hand, the radially inner hub 71 of the impeller 7 comes into contact with the opposite end of the sleeve receptacle 16 facing away from the suction mouth during its rotational movement, so that a bearing of the impeller 7 is provided in the axial direction. Here in the exemplary embodiment, the suction-side, radially inwardly disposed hub edge 71 of the impeller 7 is seated opposite the edge of the hub 16 in the suction direction SR in such a way that they slide against one another. On the other hand, the suction mouth-side end of the end piece of each blade of the impeller dives into a cutout at the outlet of the inlet pipe 11 in such a way that there is formed a radial support for the impeller. If necessary, this can also be dispensed with, ie the foot extension of each wing, which lies radially further outwards, turns freely and then does not come into contact with the stop ring 14b. In any case, the outer seated stop ring 14b closes at the same time the edge gap SP between the suction-side ends of the blades of the impeller 7 and the outer pump housing PG largely liquid-tight. Possibly. can there slide along the edge of the respective wing facing the exit of the inlet pipe on the thrust washer 14b, so that it is additionally supported in the axial direction.

In this version, the storage takes place as far radially inward as possible, so that there the circumferential speed of the impeller 7 is minimized at the storage 13b, 14b. Similarly, practically no axial and radial edge gap SP in the region of the bearing point of sliding portion 13b and stop ring 14b by the attractive force on the impeller 7 is present, whereby also here the sealing effect to reduce the reflux is given as in the first embodiments. In any case, the return flow of water in the Suction channel reduced, large component tolerances are still significantly reduced for the effective operation of the pump in importance.

For all contact points between the thrust ring and the respective sliding area on the impeller, a low-friction and possibly abrasion-resistant or abrasion-resistant material is preferably selected.

In summary, it may be particularly useful if at the output of the intake passage 11 of the circulation pump 6, a stop ring such as 14 in FIG. 3 such in the edge gap or gap SP between the wings of the impeller 7 and the output side pipe portion 12 of the intake passage 11, which is formed in particular on the pump housing PG, is arranged and the suction side edge of the impeller 7, in particular its hub and / or wings, in whose Contacted rotational movement, that the suction-side front portion of the gap space or edge gap SP is largely liquid-sealed and in addition an axial and possibly radial bearing for the impeller is formed on the suction side. The stop ring thus acts as a sealing ring and at the same time as a thrust bearing and possibly also as a radial bearing for the impeller.

Possibly. the impeller may have on its suction-side hub a cover disc protruding counter to the suction direction. Then, preferably, this has a corresponding sliding area, with which the impeller rolls on the thrust ring.

For hydraulic efficiency optimization of the circulation pump and use of an undesirable hydraulic leakage, the thrust bearing for the impeller is laid in the suction region of the pump, in particular integrated. For this purpose, a stop ring is fixedly mounted in the suction pipe of the pump housing, and the appropriate counterpart, ie the sliding area at the suction side edge of the suction mouth of the impeller and / or its possibly suction side arranged cover sits in a corresponding position in the impeller.

Conveniently, the entire impeller or the impeller shell, in particular its suction-side part, consist of a lubricious material. An extra, separate slip ring as a single part can therefore be omitted.

Both parts, ie thrust ring and sliding portion of the impeller, result in the working position when rotating the impeller, a movable, rotating sealing and sliding surface. This sliding surface can advantageously have small, defined grooves that optimize the structure and the existence of a water slide film.

Possibly. It may be expedient if in a second step, a front radial bearing for the impeller in the run-up ring is integrated by suitable shaping.

In particular, at least the suction-mouth-side, front-side sliding region of the impeller and / or the thrust ring may be made of a sliding-modified, in particular as low-friction and abrasion-resistant material, in particular plastic. Possibly. Instead, a corresponding coating, which is friction and abrasion resistant, may be provided instead. If appropriate, the sliding region of the impeller may also be formed by a sliding ring which is fixedly mounted, in particular integrated, on the suction-side end edge of the impeller.

For the integration of an axial and / or radial bearing for the suction mouth of the impeller in the feed of the pump housing, it may possibly also be advantageous if the thrust ring is provided in its center with an axle fixation, in particular Achshalterungshülse, from the spokes to the outside extend holding an outer contact ring. In the Achshalterung the suction-side end portion of a fixed axis or elongated body is held on the rear of the Achshalterung adjacent to this, the impeller is rotatably mounted. The impeller is then preferably directly connected to the rotor extrusion of the recirculation pump, i. Impeller and rotor of the circulation pump rotate around the fixed axis. Such a radial bearing has lower radial friction losses because of its small diameter.

• hydraulische Wirkungsgradverbesserung
• Vermeidung der Rückströmungen durch den Spalt im Ansaugbereich, da der Spalt gegen Null geht (Wassergleitfilm).
• Das hydraulische System wird aufgrund der definierten Anlaufstelle im Ansaugbereich unempfindlicher bezüglich Fertigungstoleranzen, da diese nicht mehr in den Wirkungsgrad eingehen - leichter zu fertigen, da größere Toleranzen möglich.
• Eventuell auch eine Kostenreduktion, wenn Flügelrad aus gleitmodifiziertem Kunststoff (z.B. Teflonverstärkter Kunststoff) hergestellt oder beschichtet ist.

Advantages of the different embodiments are in particular:

• hydraulic efficiency improvement
• Prevention of backflow through the gap in the intake because the gap is close to zero (water slide film).
• The hydraulic system is less sensitive due to the defined contact point in the intake with respect to manufacturing tolerances, as these are no longer in the efficiency - easier to manufacture, as larger tolerances possible.
• Possibly also a cost reduction, if impeller of slide-modified plastic (eg Teflon-reinforced plastic) is manufactured or coated.

LIST OF REFERENCE NUMBERS

1

Dishwasher,

2

washing area,

3

walls

4

Door,

5

Receiving basket,

6

circulation pump,

6a

circulation pump,

6b

circulation pump,

7

Impeller (impeller),

8th

Axis of rotation

9

facing the end,

10

body,

11

intake duct,

12

Pipe area,

13

Sliding area of the impeller,

13a

Sliding area of the impeller,

13b

Sliding area on the suction side edge of the wing,

14

Thrust ring,

14a

stepped stop ring,

14b

modified thrust ring on hub or sleeve receptacle,

15

Drive shaft,

151

suction end of the sleeve receptacle

16

Sleeve receiving,

17

spoke

Pump according to the prior art:

6s

circulation pump,

7s

Wheel,

8s

Axis,

9s

Drive shaft,

10s

thrust bearing,

11s

intake duct,

12s

Axial gap,

13s

Rotor of the prime mover,

HS

mainstream

NS

Nbenströmung

SP

marginal gap

N / A

hub

PG

pump housing

SR

Suction direction of the pump

141

step

71

Hub of the wheel

Claims (11)

Dishwasher (1), in particular domestic dishwasher, with a washing compartment (2) for receiving crockery, cutlery or similar objects to be cleaned, wherein the washing compartment (2) via at least one circulation pump (6; 6a, 6b) water is supplied and wherein the circulation pump (6; 6a; 6b) comprises a fixed, centrally on a rotatable impeller (7) and bounded by a pipe portion (12) suction duct (11),
characterized,
in that the impeller (7) has at its end (9) of its body (10) or its drive shaft (15) facing the surrounding tube region (12) of the intake channel (11) a sliding region (13; 13a; 13b) and a housing (PG) on the axially of the impeller (7) facing the end of the tube portion (12) or an associated sleeve receptacle (16) with a relative to the suction channel (11) fixed stop ring (14; 14a, 14b) is provided and in operation, the sliding region (13; 13a; 13b) is rotatable with respect to the thrust ring (14; 14a; 14b), the sliding region and the thrust ring (13; 13a; 13b; 14; 14a; 14b) being a bearing for the impeller (7) and the sliding region and the thrust ring (13; 13a; 13b; 14; 14a; 14b) in dual function form a sealing system against the return of water into the suction channel (11). Dishwasher (1) according to claim 1,
characterized,
in that the sliding region and the thrust ring (13; 14; 13a; 14a; 13b; 14b) form an axial bearing for the impeller (7). Dishwasher (1) according to one of the preceding claims,
characterized,
in that the sliding region and the thrust ring (13a; 14a; 13b; 14b) form a radial bearing for the impeller (7). Dishwasher (1) according to one of the preceding claims,
characterized,
that the sliding of and thrust ring (13; 14; 13a; 14a; 13b; 14b) bearing formed is water lubricated. Dishwasher (1) according to one of the preceding claims,
characterized,
that the impeller (7) outside of this bearing (13; 14) is free from its axial movement inhibiting bearing points (10s). Dishwasher (1) according to one of the preceding claims,
characterized,
in that the sliding region (13; 13a; 13b) and / or the thrust ring (14; 14a; 14b) is or are formed by (a) annular body which is separate from the impeller (7) or the intake channel (11). Dishwasher (1) according to one of the preceding claims,
characterized,
in that the sliding region (13; 13a; 13b) and / or the thrust ring (14; 14a; 14b) is or are formed by a reinforcement, such as carbon particles, embedded in the impeller (7) or the intake duct (11). Dishwasher (1) according to claim 7,
characterized,
in that the incorporated reinforcement is integrally formed in a 2K process on the impeller (7) and / or a pipe region (12) delimiting the intake duct (11). Dishwasher (1) according to one of the preceding claims,
characterized,
that the sliding portion (13; 13a; 13b) and / or the collar ring (14; 14a; 14b) facing axially away at its surface, for example, to reduce friction formed with a Teflon coating, or are. Dishwasher (1) according to one of the preceding claims,
characterized,
that the sliding portion (13; 13a; 13b) and / or the collar ring (14; 14a; 14b) facing axially away at its surface is provided with grooves for forming a Wassergleitfilms or. Dishwasher (1) according to one of the preceding claims,
characterized,
that the impeller (7) and the intake passage (11) umgrenzender tube portion (12) are formed at least outside the axially facing ends of plastic.

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