CN114829779A

CN114829779A - Pump for water-conducting household appliances

Info

Publication number: CN114829779A
Application number: CN202080086959.5A
Authority: CN
Inventors: 斯特凡·卢茨; 汉斯-霍尔格·佩尔特曼; 托马斯·布格格拉夫; 卡丽娜·施泰谢勒
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2019-12-16
Filing date: 2020-12-02
Publication date: 2022-07-29
Also published as: DE102019219703A1; WO2021121997A1; EP4077948A1

Abstract

The invention relates to a pump (13) for a water-conducting household appliance (1), wherein the pump (13) comprises a pump motor (14) having a rotor (15) which runs in a fluid medium to be conveyed, wherein the pump is designed such that the rotor (15) of the pump motor (14) comprises, on the extension of the rotor, a device of at least six magnetic poles (16; 17) having a Halbach magnetization, and the rotor (15) has no separate body for a magnetic circuit.

Description

Pump for water-conducting household appliances

Technical Field

The invention relates to a pump for a water-conducting household appliance and a dishwasher having such a pump, wherein the pump comprises a pump motor having a rotor which runs in a fluid medium to be delivered, according to the preamble of claim 1.

Background

In water-conducting household appliances, such as dishwashers, washing machines or dryers, it is known to use an electrically driven pump for draining and/or circulating a fluid. For high reliability, so-called canned pumps are used, in which the rotating part of the pump motor, i.e. the rotor, is in the fluid medium to be conveyed. It is also known here that the rotating rotor forms a so-called outer rotor, i.e. that the stator is provided as a fastening element, radially further outwards, as seen from the central motor shaft.

Such an outer rotor is known, for example, from DE 66000235U.

Disclosure of Invention

The aim of the invention is to improve the efficiency of such a pump with a low space requirement.

The invention achieves this object by means of a pump having the features of claim 1, a pump having the features of claim 9 and a dishwasher having the features of claim 14. With regard to further advantageous embodiments and features of the invention, reference is made to claims 2 to 8 and 10 to 13 and 15.

The high pole count is achieved by the rotor of the pump motor comprising on the extension of the rotor a device consisting of at least six magnetic poles with Halbach magnetization, so that high rotational speeds suitable for high efficiency can be easily achieved. By having a rotor without a separate body for the magnetic circuit, the rotor can require less material application and also have only a very small moment of inertia. Furthermore, by dispensing with an outer ring or similar component for the magnetic circuit, the diameter of such a pump can be kept very small, which reduces the space requirement.

The efficiency can be particularly high when the rotor comprises at least eight poles. Ten, twelve or more poles can also be realized on the rotor.

Advantageously, the pump can be a drain pump and nevertheless has a very small outer diameter of less than 45 mm.

Advantageously, the pump according to the invention can also be a circulation pump for water, optionally spiked with cleaning agents, rinsing agents and/or drying agents, and nevertheless has a very small outer diameter of less than 55 mm.

In order to minimize the moment of inertia and at the same time optimize the material use and have a small diameter, the rotor is completely free of a casing that fixes and/or protects the rotor.

The rotor can form an integral, uniform body, for example a composite body with embedded metal particles, which is simple to manufacture and light.

In particular, the pump can also be a heat pump, which can simultaneously deliver fluid and heat, so that a dual function is achieved overall and without additional installation space.

In the embodiment according to claim 9, the rotor of the pump motor comprises a device of magnetic poles on the extension of the rotor, the number of magnetic poles being greater than the number of wound teeth of the stator which is further radially inside. The rotor is therefore designed as a so-called outer rotor which, when the pump motor is in operation, radially surrounds the preferably stationary stator which is arranged inside further on the outside. Thus, a very high efficiency of the pump can be achieved while reducing the outer diameter. Since the friction of the pump is proportional to the fourth power of the radius, the reduction of the radius is very important for the increase of the efficiency and the reduction of the friction.

For example, it is possible to realize that the stator has four teeth and the rotor has six or eight poles. Alternatively, the stator can have six teeth and the rotor eight poles, or for example the stator nine teeth and the rotor ten poles. It is also possible to realize that the stator has ten teeth and the rotor has twelve poles.

The higher the number of poles of the rotor designed as an outer rotor is selected, the smaller the magnets thereof or the magnetic material thereof can be made in an advantageous manner. It therefore follows that the diameter of the rotor and of the pump motor can be reduced, which saves installation space for the pump in a water-conducting household appliance. The smaller the radial thickness of the respective magnet or magnetic material of the rotatable outer rotor is selected, the smaller the mass of the outer rotor is advantageously. This ensures that the rotor reduces the surge excitation during rotational operation, making the pump motor quieter during operation, i.e., reducing the pump motor operating noise. Furthermore, the load on the rotor of the pump motor and the bearing, in particular the rotary bearing, of the drive shaft mounted thereon is reduced.

In particular, the household appliance equipped with one or more pumps of the above-mentioned type may be a dishwasher. In this case, the power of the at least one pump is typically 70 to 100 watts, when the at least one pump is used to circulate and/or remove water, optionally mixed with cleaning agents, rinsing agents and/or drying agents, the rotor of the at least one pump itself running in the fluid. In such household appliances, a circulation pump for circulation and a separate drain pump for draining off the fluid are usually provided.

With the invention for improving the efficiency, it is possible in such a device, for example, to increase the rotational speed from 4300 revolutions per minute to approximately 5000 revolutions per minute, while at the same time reducing the outer diameter of the respective pump.

Drawings

Additional advantages and features are derived from the embodiments of the inventive subject matter shown in the drawings and described below.

The figures show:

fig. 1 shows a perspective view from diagonally in front of an embodiment of a water-conducting household appliance, here for example a dishwasher with a door on the front side,

figure 2 shows a cross-section of an exemplary pump,

figure 3 shows an axial view of a stator surrounded by an eight-pole rotor with six teeth,

figure 4 shows an axial view of a stator with nine teeth surrounded by a rotor with ten poles,

fig. 5 shows an axial view of a stator which also has nine teeth but is here surrounded by a rotor with twelve poles.

Detailed Description

The dishwasher schematically shown in fig. 1 is a domestic dishwasher and shows an exemplary water-conducting domestic appliance 1. The dishwasher has a rinsing container 2 for receiving the rinsing product to be treated (e.g. dishes, pots, cutlery, glasses, cookware, etc.) as a component of a device body 5 which is partially open or closed to the outside. In this case, the rinsing product can be held in the cutlery basket 11 and/or the cutlery drawer 10, for example, and the rinsing liquid can be applied there. Here, rinsing liquid is understood to mean fresh water with or without a cleaning agent and/or rinsing agent and/or drying agent or, in particular, water circulating during operation. The rinsing container 2 can have an at least substantially rectangular plan arrangement with a front side V facing the user in the operating position. The front side V here forms part of a kitchen front consisting of kitchen furniture placed side by side or is not yet associated with further furniture in a separate device. Proceeding from the front side V, the dishwasher extends to the left and right in the transverse direction Q. In the transverse direction Q, the dishwasher 1 often has an extension of 45, 50 or 60 cm. In the depth direction to the rear of the front side V, there is typically also an extension of about 60 cm. These values are not mandatory.

In particular, the rinsing container 2 can be closed at this front side V by a door 3. The door 3 is partially opened in fig. 1 and is then shown tilted with respect to the vertical position. In contrast, in the closed position of the door, the door is instead vertical and, according to the figures, can be pivoted forward and downward in the direction of arrow 4 about a lower horizontal axis in order to open the door, so that the door is at least approximately horizontal in the fully open position.

The outer side facing the user and the front side V, which is vertical in the closed position of the door, can equip the door 3 with a cover 6 in order to thus experience an optical and/or tactile improvement and/or adaptation to the surrounding furniture.

The household appliance, here the dishwasher 1, is constructed as a stand-alone or as a so-called partially or fully integrated device. In the last case, the device body 5 can also be substantially closed with the outer wall of the rinsing container 2. This peripheral housing can then be unnecessary.

In the embodiment according to the figures, the movable door 3 is provided, in its upper extent, with an operating panel 8 extending in the transverse direction Q of the dishwasher, which can comprise a handle slot 7 contacted by the front side V to enable manual opening and/or closing of the door 3.

In the lower region of the dishwasher there can be a seat for accommodating in particular functional elements, such as a circulating or draining pump 13, which at the same time can, but need not, also form a heat pump.

Other water-conducting household appliances 1, such as washing machines or dryers, can also be equipped with one or more such pumps 13. The pump 13 comprises in each case a pump, a pump motor 14 with a rotor 15 running in the fluid medium to be conveyed, which medium is formed by water optionally admixed with cleaning agents, rinsing agents and/or dryers.

The illustrated rotor 15 of the pump motor 14 comprises at least six

magnetic poles

16, 17 on its annular extension, which have halbach magnetizations. Thus, the magnetic flux can be operated closed without requiring a separate body for the magnetic circuit. It is thus possible to dispense with an outer ring or a similar iron or steel body. The rotor 15 has no separate body for the magnetic circuit. In particular, the rotor 15 is also free of other casings to stabilize and/or protect the rotor. The rotor 15 can be rotated by means of a shaft 18 about a stator 19 which is arranged radially further inside and thus forms an outer rotor.

The rotor 15 can also comprise a plurality of

poles

16, 17, including at least eight, ten or twelve

poles

16, 17 for high rotational speed and efficiency improvement. The pole 16 is here a magnetic north pole and the pole 17 is a magnetic south pole. The magnetic north pole 16 and the magnetic south pole 17 together form a pole pair, respectively.

Since the overall outer diameter of the pump 13 can be kept particularly small by dispensing with an additional outer ring for the magnetic circuit on the rotor 15, it is possible to achieve: the pump 13 is a drain pump for draining dirty fluid from the household appliance 1 and has an outer diameter of less than 45 mm here. The following can also be realized: the pump 13 is a circulation pump for circulating rinsing liquid, i.e. water mixed with cleaning agent, rinsing agent and/or drying agent, and has an outer diameter of less than 55 mm.

The rotor 15 can constitute an integral unified body and is for example a composite body with embedded metal particles manufactured in an injection-moulding process. This does not require a sheet structure. The magnetic field lines in the rotor 15 are also closed without a separate circuit body by the halbach magnetising part in the manufacturing process. With a one-piece construction, a very low-cost solution is also achieved. External machining is also unnecessary compared to a combined rotor. The integrated magnet ring with the arched magnetization can be used directly in a fluid medium, since the magnet ring is corrosion-resistant as described. Since a body for the magnetic circuit is also not required, it does not have to be protected against abradable conveying media.

In order to realize the pump drive and the rotor 15, which is designed as an external rotor, several possibilities are provided:

a ferrite ring can be formed for forming the rotor, which is formed without a magnetic circuit in the halbach magnetization pre-positioning or injected with a synthetic material;

neodymium associated with the synthetic material can be injected to form an outer rotor ring with a halbach orientation of magnetization;

ferrite material in relation to the synthetic material can be injected to form the outer rotor ring, wherein either only the ring is made of a magnetically containing material and then a low cost material is injected or installed for the access to the shaft 18, or the entire rotor 15 including its connection to the shaft 18 is made of a magnetically containing material. The formed ring body can thus be fixed or sprayed with a synthetic material in a torque-proof manner concentrically on the shaft 18 in the installation position. In order to be able to implement this design, the ring body is ideally centrally discharged and can thus be moved onto the shaft 18.

In total, a variant of injection molding ferrite material in relation to synthetic material to form an outer rotor ring with halbach magnetising is shown, which is very good (less unbalance, less asymmetry) in terms of wave excitation as a very low-cost solution. It is also very effective in calculating the amount of activation.

Alternatively, the pump 13 is a heat pump, in particular as long as the pump is a circulation pump and at the same time has a dual function.

It is particularly advantageous if the number of

poles

16, 17 of the rotor 15 is greater than the number of wound teeth 20 of the stator 19. In order to be able to also show a low-cost wire wrapping technique on the stator 19, it is also possible to provide approximately four to ten teeth 20 on the stator 19.

The rotor (15) of the pump motor (14) comprises, on the extension of the rotor, a device of magnetic poles, the number of which is greater than the number of wound teeth of the stator, which is further built in the radial direction.

For example, the stator 19 can have four teeth 20 and the rotor 15 has six or eight

poles

16, 17.

Alternatively, as shown in fig. 3, the stator 19 can have six teeth 20 and the rotor 15 has eight

poles

16, 17.

Alternatively, as shown in fig. 4, the stator 19 can have nine teeth 20 and the rotor 15 ten poles.

It is likewise possible to realize that the stator 19 has ten teeth 20 as in fig. 5 and the rotor 15 has twelve poles. Other possibilities are also contemplated.

It is particularly desirable to make the water-conducting household appliance 1 as a dishwasher with at least one such pump 13. In particular, the dishwasher is a domestic dishwasher, wherein at least one pump 13 is used for the circulation (circulation pump) and/or removal (drain pump) of water, optionally spiked with detergent, rinsing agent and/or desiccant, and the rotor 15 of the at least one pump 13 runs in this fluid itself, wherein the pump has a small diameter and a very high efficiency.

List of reference numerals

1 a dishwasher, comprising a dishwasher,

2, the container is washed by the water,

3, a door is arranged at the front part of the door,

4 the direction of the opening is 4, and the opening direction is,

5 the main body of the device is provided with a plurality of grooves,

6, a decorative plate is arranged on the upper surface of the base,

7 a groove of the handle is arranged on the handle,

8 an operation panel is arranged on the base plate,

10 a drawer for tableware,

11 a basket for tableware, wherein the basket for tableware,

12 a base plate and a plurality of fixing plates,

13 a pump for pumping the liquid into the liquid storage tank,

14 a pump motor for a pump, and,

15 the rotor of the motor is driven by a motor,

16 a magnetic north pole, and a magnetic north pole,

a magnetic south pole of 17 magnetic poles,

the axis of the shaft is 18, and the shaft,

a stator (19) is arranged on the stator,

20 the teeth of the stator, and the teeth,

q is in the transverse direction,

v the front side of the dishwasher,

b, bottom.

Claims

1. Pump (13) for a water-conducting household appliance (1), wherein the pump (13) comprises a pump motor (14) having a rotor (15) located radially outside in a fluid medium to be conveyed,

it is characterized in that the preparation method is characterized in that,

the rotor (15) of the pump motor (14) comprises, on the extension of the rotor, a device consisting of at least six magnetic poles (16; 17) having a Halbach magnetization, and the rotor (15) has no separate body for the magnetic circuit.

2. Pump (13) according to claim 1, characterized in that the rotor (15) comprises at least eight poles (16; 17).

3. The pump (13) according to claim 1 or 2, characterized in that the pump (13) is a drain pump and has an outer diameter of less than 45 millimeters.

4. A pump (13) according to claim 1 or 2, characterized in that the pump (13) is a circulation pump and has an outer diameter of less than 55 mm.

5. Pump (13) according to any one of claims 1 to 4, characterized in that the rotor (15) is free of a jacket fixing and/or protecting it.

6. Pump (13) according to any one of claims 1 to 5, characterized in that the rotor (15) forms an integral unified body.

7. Pump (13) according to any one of claims 1 to 5, characterized in that the rotor (15) forms a composite material body with embedded metal particles.

8. Pump (13) according to any one of claims 1 to 6, characterized in that it is a heat pump.

9. Pump (13) for a water-conducting domestic appliance (1), wherein the pump (13) comprises a pump motor (14) having a rotor (15) which runs in a fluid medium to be delivered, in particular a pump as claimed in one of claims 1 to 8,

it is characterized in that the preparation method is characterized in that,

the rotor (15) of the pump motor (14) comprises, on the extension of the rotor, a device of magnetic poles (16; 17) which is greater than the number of wound teeth (20) of a stator (19) which is arranged further in the radial direction.

10. Pump (13) according to claim 9, characterized in that the stator (19) has four teeth and the rotor (15) has six or eight poles (16; 17).

11. Pump (13) according to claim 9, characterized in that the stator (19) has six teeth (20) and the rotor (15) has eight poles (16; 17).

12. Pump (13) according to claim 9, characterized in that the stator (19) has nine teeth (20) and the rotor (15) has ten poles (16; 17).

13. Pump (13) according to claim 9, characterized in that the stator (19) has ten teeth (20) and the rotor (15) has twelve poles (16; 17).

14. Dishwasher (1) with at least one pump (13) according to one of claims 1 to 13.

15. A dishwasher (1) as in claim 14, characterized by at least one pump (13) for circulating and/or draining water, possibly spiked with detergent, rinse and/or desiccant, wherein the rotor (15) of at least one pump (13) itself runs in a fluid.