EP4301987A1

EP4301987A1 - Water-conducting domestic appliance comprising a pump device with an external rotor motor

Info

Publication number: EP4301987A1
Application number: EP22708524.8A
Authority: EP
Inventors: Stephan Lutz; Carina Steichele; Thomas Wecker; Stefan Pollithy; Johannes Kienmoser
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2021-03-05
Filing date: 2022-02-17
Publication date: 2024-01-10
Also published as: DE102021202130A1; DE102021202130B4; WO2022184445A1; CN220452214U

Abstract

A water-conducting domestic appliance (1), in particular a domestic dishwasher, with at least one heatable pump device (13) which has an electric motor (14), the electric motor (14) comprising a stator (19) and a rotor (15) which is substantially in the form of a cylinder jacket, surrounds a shaft (18), and, as it rotates, drives a conveying member (16), in particular an impeller, the shaft (18), being arranged in an upright installation position, is designed such that the rotor (15) runs around the stator (19) radially on the outer side and is provided on its radial outer side with a plurality of conveying attachments (17).

Description

WATER FEEDING HOUSEHOLD APPLIANCE COMPRISING A PUMP DEVICE WITH AN EXTERNAL MOTOR

The present invention relates to a water-carrying household appliance, in particular a household dishwasher, with at least one heatable pump device which has an electric motor which comprises a stator and a rotor which is essentially in the form of a cylinder jacket and surrounds a shaft and which, as it rotates, drives a conveying element, in particular an impeller , wherein the shaft is arranged in an upright installation position, according to the preamble of claim 1.

Such water-carrying electrical household appliances can be dishwashers or washing machines in particular. The pumping devices can be used there primarily for circulating liquids. In particular, so-called canned pumps are used because of their high reliability, in which the rotating part of the pump motor, the rotor, is located in the liquid medium to be pumped. It is also known that the rotating rotor forms what is known as an external rotor, ie—seen from a central motor shaft—is radially further outward than the stationary stator. So-called internal rotors are also known, in which the rotor lies further inwards than the fixed stator.

Usually, the electromotive part and the hydraulic part, ie the liquid-conveying part, of the pumping device are axially separated from one another, which requires a considerable amount of installation space for the pump and requires a horizontal installation position. This makes changing the water and venting the pumping device more difficult, as there is always water in the pumping device.

An upright installation position of the pumping device is therefore advantageous. However, this is only possible if the axial extent of the pumping device is small, so that there is sufficient height available for this installation position. This can be made possible in particular by integrating the hydraulic and electromotive parts of the pumping device. However, the problem arises of conveying the liquid effectively and with high efficiency from the bottom to the top.

The invention is based on the problem of achieving a good solution for this. The invention solves the problem with a household appliance having the features of claim 1. With regard to further advantageous configurations and features of the invention, reference is made to claims 2 to 17.

The invention creates a water-conducting household appliance, in particular a household dishwasher, with a high level of effectiveness and a very high efficiency of the heatable pump device with a shaft in an upright installation position, in that the rotor runs around the stator radially on the outside and on its radial outside with a plurality of conveying Approaches is provided. As a result, not only is an impeller rotating on the underside of the pumping device, in particular a rotating impeller, available as a conveying element, which conveys essentially radially outwards into an annular gap, but the external rotor driven by the stator with the conveying attachments is also available as an additional conveying element provided in its outer shell, whereby the liquid is also actively conveyed upwards via the path in the annular gap. The additional effort is minimized by arranging the conveying lugs on the outside of the rotor.

The lugs are preferably arranged directly on the rotor. Then there is no need for any type of holding means for these approaches. The design and assembly effort is thus minimized. The rotor and the attachments located thereon can also be formed together particularly favorably as a one-piece structural unit.

In particular, the conveying lugs are distributed evenly around the outer circumference of the rotor, i.e. every two conveying lugs that are adjacent in the circumferential direction are spaced apart from one another by the same circumferential angle.

If the conveying projections leave axial passage openings between one another, the liquid can be conveyed upwards very quickly and with little resistance. Disturbing turbulence or cavitation can be largely avoided.

In order to achieve this, the through-openings are advantageously at least 5 millimeters long in each case in the circumferential direction. This can cause blockages any solid particles entrained in the liquid, such as lemon stones or pieces of bread crust, can be reliably avoided.

For a good passage of liquid with a high conveying intensity at the same time, it is advantageous if the through-openings of different conveying attachments are aligned one behind the other in the axial direction.

If the conveying projections have a maximum radial extension of between 2 and 15 millimeters outwards from a base body in the shape of a cylinder jacket, the annular gap can be largely swept over to convey liquid without the resistance becoming great.

In particular, the conveying projections can have a radial extension that varies between a minimum and a maximum extension. The remaining free width in the annular gap thus also varies. This gives the approaches a shovel-like shape.

In a particularly advantageous manner, the radial extension of each extension with respect to the circumferential direction increases continuously from one end of the extension to the other up to the maximum extension. At the same time, it has a certain pitch in the axial direction, ie in or against the axial conveying direction, similar to the turns of a screw thread.

Furthermore, it is particularly favorable if the plurality of conveying attachments extends over the entire axial length of the rotor. The conveying aids thus act uniformly over the entire conveying path that rises up from the lower conveying element to an upper outlet, in particular a tangential outlet. In particular, water to which rinsing or rinsing agent and/or drying agent has been added can be considered as the liquid to be circulated.

Each conveying approach does not have to completely run around the circumference like a thread, but can surround a quarter to seven eighths of the circumference of the rotor. The liquid is not only conveyed axially, but also set in rotation (friction minimization). The advantages and rules mentioned can be applied in particular to such an electric motor which is what is known as an external rotor, in which the rotor is arranged outside of a stator which is located radially further inwards. This means that overall, expensive material can also be saved for the stator, which requires far less material than a so-called inner rotor.

For a very simple construction, it is very favorable to form the rotor from a plastoferrite or a plastic matrix with introduced neodymium particles, in particular in an injection molding process.

A particularly great unity and simplicity of construction is possible when the rotor and both a central shaft or means supporting the rotor on the shaft and the rotor with the central shaft or means connecting bracket(s) having a radial component, are formed in one piece, in particular by a coextrusion process. This process can also be carried out inexpensively in large series. The weight of such a rotor is also very low.

The connecting brackets protrude in particular pointedly - similar to a ship's bow - downwards in the direction of the liquid and conveying element. This results in a flow optimization.

For effective heat input into the liquid, the pumping device has a heating jacket which extends in the circumferential direction and, in particular, encompasses a large area, in a favorable radial manner on the outside. This can rest directly on the outside of a housing wall in the manner of a sleeve and allow optimum heat transfer to the housing wall.

The effectiveness is further increased if the rotor is located completely within the axial extent of the heating jacket. If the rotor does not protrude axially beyond the heating jacket, the liquid conveyed here is heated along its entire path in the pumping device, which ensures a very high degree of efficiency of the heating. In this case, the outer wall of the motor housing can preferably be omitted. The bell-shaped rotor connected to the impeller rotates directly inside the heating tube. Due to the rotation of the outer surface, there is reduced friction (splashing losses) in this area with the liquid rotating in the heating pipe and thus an increase in efficiency. At the same time, this arrangement increases the rotational speed of the medium to be pumped - and thus the heat dissipation on the pipe's inner surface, which is heated from the outside. These effects are particularly noticeable due to the attachments attached or molded on the outside of the outer circumference of the rotor. Also, parts of the impeller - such as blades - can be molded from magnetic material to reduce the complexity of the rotating assembly.

In particular, the axial extent of the heating jacket is between 3 and 10 centimeters, so that the upright pumping device can be accommodated below a rinsing tank.

An exactly vertical installation position with a main component of the conveying direction from bottom to top is also possible.

Further advantages and features result from the exemplary embodiments of the subject matter of the invention which are illustrated in the drawing and described below.

In the drawing shows:

1 shows a schematic perspective view diagonally from the front of an embodiment of a water-bearing household appliance, here by way of example a dishwasher, with a front door here,

2 is a cross-sectional view of an exemplary pump;

3 shows an individual view of the rotor with lugs, holder and holding means for fixing on the shaft,

4 shows a view in the axial direction of a rotor of the external rotor with projections provided on the outside. The water-carrying domestic appliance 1 shown schematically in FIG. 1 is only an example of a dishwasher, namely a domestic dishwasher. As a component of an appliance body 5 that is partially open or closed to the outside, it has a washing compartment 2 for accommodating items to be washed, such as crockery, pots, cutlery, glasses, cooking utensils, and the like. The items to be washed can be held, for example, in crockery baskets 11 and/or a cutlery drawer 10 and can be acted upon by so-called washing liquor. Washing liquor is understood to mean water that is fresh or, in particular, water that is circulating during operation, with or without cleaning agent and/or rinse aid and/or drying agent. The washing container 2 can have an at least essentially rectangular outline with a front side V facing a user in the operating position. This front side V can form part of a kitchen front made of kitchen furniture standing next to one another or, in the case of a stand-alone appliance, can also be unrelated to other furniture. From the front V, the dishwasher extends in the transverse direction Q to the left and right. In the transverse direction Q, the dishwasher 1 often extends 45, 50 or 60 centimeters. In the depth direction from the front V to the rear, the extension is often also around 60 centimeters. The values are not mandatory.

The washing compartment 2 can be locked by a door 3 in particular on this front side V. This door 3 is shown in FIG. 1 in a partially open position and then in a position at an angle to the vertical. In its closed position, however, it stands upright and according to the drawing it can be swung open about a lower horizontal axis forward and downward in the direction of arrow 4 so that it is at least almost horizontal in the fully open position.

The door 3 can be provided with a decorative panel 6 on its outer and front side V, which is vertical in the closed position and faces the user, in order to experience a visual and/or haptic enhancement and/or an adaptation to the surrounding kitchen furniture.

The household appliance 1, here the dishwasher, is designed as a stand-alone appliance or as a so-called partially integrated appliance or else as a fully integrated appliance. In the latter case, the device body 5 can also essentially be connected to the outer walls of the lock the rinsing tank 2. A housing surrounding this on the outside can then be dispensed with.

In the exemplary embodiment according to the drawing, the movable door 3 is assigned in its upper area a control panel 8 which extends in the transverse direction Q of the dishwasher and which can include an access opening 7 accessible from the front V for manually opening and/or closing the door 3 .

In the lower area of the dishwasher there can be a base 12 for accommodating in particular functional elements such as a circulating or draining pump device 13, which can also be provided with a heater and thus form a heating pump. A driving electric motor 14 is integrated into this pumping device 13.

Other household appliances 1, such as washing machines or tumble dryers, can also be provided with one or more such circulating pump devices for conveying liquids and/or for other purposes.

According to FIG. 2, the electric motor 14 is integrated into the pump device 13 in such a way that it comprises a rotor 15 running in a liquid medium to be pumped, which can be formed by water possibly mixed with cleaning agent, rinsing agent and/or drying agent.

The rotor 15 of the pump motor 14, which is shown in FIG. So this is an outrunner.

Like the entire drilling device 13, the pump motor 14 is arranged in an upright, in particular vertical, installation position. During its rotation, the pump motor 14 drives a conveying element 16, in particular an impeller, which is arranged here at the lower end of the shaft 18, which is also upright. The above-mentioned washing liquor is conveyed not only by the conveying element 16 but also by conveying attachments 17 which are arranged on the radial outside of the rotor 15 .

These projections 17 are arranged directly on the rotor 15. In particular, they are an integral part of a common assembly of at least the rotor 15 and lugs 17. These components can be formed very effectively in a 2K process. In order to make this one-piece structure possible, the rotor 15 can be formed from a plastoferrite or a plastic matrix with introduced neodymium particles, in particular in an injection molding process. The lugs 17 themselves can be molded from the same base material, but do not have to include ferrite or neodymium particles.

The conveying projections 17 do not have to run around the rotor 15 by 360° in the circumferential direction U, but they can leave axial through-openings 20 between one another. These can each be at least 5 millimeters long in the circumferential direction U.

A plurality of conveying attachments 17 are thus arranged one behind the other over the axial path. These can in particular be arranged so uniformly that the through-openings 20 of different conveying attachments 17 are arranged one behind the other in axial alignment. This results in continuous channels at the through-openings 20 over the entire axial length. Furthermore, conveying projections 17 can be provided over the entire axial length of the rotor 15.

The conveying projections 17 shown here have a maximum radial extent of between 2 and 15 millimeters, which point outwards from a basic body 21 of the rotor 15 in the shape of a cylinder jacket.

In this case, the projections 17—in contrast to threads—do not have to have a constant radial extent over their entire extent in the circumferential direction U, but this can vary between a minimum and a maximum extent. In particular, the radial extent of each projection 17 with respect to the circumferential direction U increases continuously from one end of the projection 17 to the other end up to the maximum extent. In an axial view, the projections 17 therefore each have conical outer surfaces.

The circumferential length of a respective attachment 17 can be adjusted in a flow-optimizing manner. In particular, each conveying attachment 17 runs around over a quarter to over seven eighths of the circumference of the rotor 15.

For example in Figure 3 it can be seen that not only the rotor 15 and the attachments 17 held thereon can form a common, integrated structural unit, but the rotor 15 can also be connected to a central shaft 18 or at least to means holding the rotor 15 on the shaft 18 23 as well as with connecting bracket(s) 24, which have a radial component, form a common structural unit formed in one piece, in particular by a coextrusion process. Here is shown in the drawing that the shaft 18 is separate, in particular made of metal. On the other hand, means 23 holding the rotor 15 on the shaft 18 together with connecting bracket(s) 24 extending therefrom, which have a radial component, and the rotor 15 with the lugs 17 are a common unit formed in one piece. The brackets 24 leading radially outwards from the shaft to the rotor open centrally into a tip 25 which faces the flow and reduces the flow resistance.

The pumping device 13 here also has a heating jacket 22 extending in the circumferential direction U radially on the outside. In this case, the rotor 15 is located completely within the axial extent of the heating jacket 22 . In order to enable the upright installation position of such an installation position under the washing container 2 in the base 12, the axial extent of the heating jacket is between 3 and 10 centimeters. An exactly vertical installation position can then be achieved in which the conveying direction has a main component from bottom to top. The impeller 16 is then at the lowest end, the outlet is at the upper end.

The rotor 15 can be about Halbach magnetized. With Haibach magnetization, the ferrite or neodymium particles contained in a matrix are aligned so that imprinted magnetic features result. The rotor 15 can form an integrally unitary body and can be, for example, a plastic body produced by injection molding with embedded metal particles. A slice-by-slice structure is not required. Due to the Haibach magnetization in the manufacturing process, the magnetic field lines in the rotor 15 are closed even without a separate return body. A very cost-effective solution is also achieved with the one-piece construction. External machining is also unnecessary, in contrast to composite rotors. Monolithic magnetic rings with arc-shaped magnetization can be used directly in the liquid medium because they are resistant to corrosion. Since no body is required for a magnetic return, it does not have to be protected from the possibly abrasive pumped medium.

Reference List

1 dishwasher,

2 rinsing tanks,

3 door,

4 opening direction,

5 device body,

6 decorative panel,

7 recessed grip,

8 control panel,

10 cutlery drawer,

Q transverse direction,

V front of the dishwasher,

11 dish rack,

12 sockets,

13 pumping device,

14 electric motor,

15 rotors,

16 funding body,

U circumferential direction,

17 promotional approaches,

18 wave,

19 stator,

20 through holes,

21 body,

22 heating jacket,

23 means keeping on the wave,

24 brackets,

25 tip

Claims

patent claims

1. Water-bearing household appliance (1), in particular

Household dishwasher, with at least one heatable pump device (13) which has an electric motor (14), the electric motor (14) comprising a stator (19) and a rotor (15) which is essentially in the shape of a cylinder jacket and surrounds a shaft (18) and which at its rotation drives a conveying element (16), in particular an impeller, with the shaft (18) being arranged in the upright installation position, characterized in that the rotor (15) runs around the stator (19) radially on the outside and is provided on its radial outside with a A plurality of promotional approaches (17) is provided.

2. Household appliance (1) according to claim 1, characterized in that the lugs (17) are arranged directly on the rotor (15).

3. Household appliance (1) according to one of claims 1 or 2, characterized in that the conveying projections (17) leave axial through-openings (20) between one another.

4. Household appliance (1) according to claim 3, characterized in that the through-openings (20) in the circumferential direction (U) are at least 5 millimeters long.

5. Household appliance (1) according to one of claims 3 or 4, characterized in that the through-openings (20) of different conveying projections (17) are axially aligned one behind the other.

6. Household appliance (1) according to any one of claims 1 to 5, characterized in that the promotional lugs (17) have a maximum radial extent of between 2 and 15 millimeters from a cylinder jacket-shaped base body (21) to the outside.

7. Household appliance (1) according to any one of claims 1 to 6, characterized in that the promotional projections (17) have a radial extent which varies between a minimum and a maximum extent.

8. Household appliance (1) according to claim 7, characterized in that the radial extension of each extension (17) with respect to the circumferential direction (U) from one end to the other end of the extension (17) increases continuously up to the maximum extension.

9. Household appliance (1) according to any one of claims 1 to 8, characterized in that the plurality of promotional lugs (17) extends over the entire axial length of the rotor (15).

10. Household appliance (1) according to any one of claims 1 to 9, characterized in that each promotional projection (17) runs around a quarter to seven eighths of the circumference of the rotor (15).

11. Household appliance (1) according to one of claims 1 to 10, characterized in that the electric motor (14) is a so-called. External rotor, in which the rotor (15) is arranged outside of a radially inner stator (19).

12. Household appliance (1) according to any one of claims 1 to 11, characterized in that the rotor (15) is formed from a plastoferrite or a plastic matrix with introduced neodymium particles, in particular in an injection molding process.

13. Household appliance (1) according to claim 12, characterized in that the rotor (15) and a central shaft (18) or the rotor on the shaft (18) holding means (23) and the rotor (15) with the central shaft (18) or the support(s) (24) connecting the means (23), having a radial component, are formed in one piece, in particular by a co-extrusion process.

14. Household appliance (1) according to one of claims 1 to 13, characterized in that the pumping device (13) has a radially outside in the circumferential direction (U) extending heating jacket (22).

15. Household appliance (1) according to claim 14, characterized in that the rotor (15) is located entirely within the axial extent of the heating jacket (22).

16. Household appliance (1) according to any one of claims 14 or 15, characterized in that the axial extent of the heating jacket (22) is between 3 and 10 centimeters.

17. Domestic appliance (1) according to any one of claims 1 to 16, characterized in that the pumping device (13) is a circulating heating pump within a domestic dishwasher.

18. Household appliance (1) according to any one of claims 1 to 17, characterized in that the installation position of the pumping device (13) is vertical and the conveying direction has a main component from bottom to top.