ELECTRIC DRIVE MOTOR, WET-ROTOR PUMP, AND HOUSEHOLD APPLIANCE

Abstract

An electric drive motor has a permanent magnet rotor with a motor shaft on which a permanent magnet carrier is fastened. A first axial end portion of the motor shaft has a seat for an impeller and the permanent magnet carrier carries at least one permanent magnet at a second axial end portion of the motor shaft. The permanent magnet carrier is pot-shaped with a pot base portion, fastened to the second axial end portion and extending radially to the motor shaft, and a circular cylinder wall portion directly adjoining the outer periphery of the pot base portion and coaxially surrounding the motor shaft. The pot base portion and the circular cylinder wall portion have an at least approximately identical or exactly identical wall thickness. There is also described a wet-rotor pump and a household appliance with such an electric drive motor.

Claims

1-16. (canceled)

17. An electric drive motor, comprising: a permanent magnet rotor having a motor shaft rotatably mounted by a bearing, and a permanent magnet carrier of said permanent magnet rotor fastened on said motor shaft; said motor shaft having a first axial end portion with a seat for an impeller and a second axial end portion opposite said first axial end portion; said permanent magnet carrier carrying at least one permanent magnet and being fastened to said second axial end portion of said motor shaft; said permanent magnet carrier being pot-shaped with a pot base portion fastened to said second axial end portion and extending at least substantially radially from said motor shaft, and with a circular cylinder wall portion directly adjoining an outer periphery of said pot base portion and coaxially surrounding said motor shaft, wherein said pot base portion and said circular cylinder wall portion have a substantially identical or exactly identical wall thickness.

18. The electric drive motor according to claim 17, wherein at least said circular cylinder wall portion of said permanent magnet carrier, or an entire said permanent magnet carrier including said pot base portion and said circular cylinder wall portion, is formed of ferromagnetic material.

19. The electric drive motor according to claim 17, wherein said circular cylinder wall portion of said permanent magnet carrier, or said pot base portion of said permanent magnet carrier, or an entire said permanent magnet carrier including said pot base portion and said circular cylinder wall portion, is produced from at least one material selected from the group consisting of a stainless steel, a soft magnetic composite material, a sintered magnetic material, and a soft magnetic plastic compound.

20. The electric drive motor according to claim 17, wherein said circular cylinder wall portion of said permanent magnet carrier, or said pot base portion of said permanent magnet carrier, or an entire said permanent magnet carrier including said pot base portion and said circular cylinder wall portion, is produced from magnetic stainless steel.

21. The electric drive motor according to claim 17, wherein the at least one permanent magnet is fastened to an outer peripheral casing wall of said circular cylinder wall portion of said permanent magnet carrier by an adhesively bonded connection.

22. The electric drive motor according to claim 21, wherein said at least one permanent magnet is one of a plurality of individual permanent magnets uniformly distributed over a periphery and fastened to said outer peripheral casing wall of said circular cylinder wall portion of said permanent magnet carrier by the adhesively bonded connection.

23. The electric drive motor according to claim 22, wherein said individual permanent magnets are circular arc-shaped permanent magnets.

24. The electric drive motor according to claim 21, wherein said permanent magnet rotor has a single annular permanent magnet which comprises a plurality of magnetic pole pairs and which is fastened to said outer peripheral casing wall of said circular cylinder wall portion of said permanent magnet carrier by the adhesively bonded connection.

25. The electric drive motor according to claim 21, wherein said at least one permanent magnet is fastened to said outer peripheral casing wall of said circular cylinder wall portion of said permanent magnet carrier by the adhesively bonded connection, which comprises a magnetically conductive adhesive.

26. The electric drive motor according to claim 17, wherein said circular cylinder wall portion of said permanent magnet carrier has an inner casing wall which coaxially surrounds said motor shaft and defines a hollow space between said permanent magnet carrier and said motor shaft, and wherein said bearing has a bearing bush extending into said hollow space.

27. The electric drive motor according to claim 26, wherein said pot base portion of said permanent magnet carrier has an inner base wall which forms an axial bearing surface which directly abuts against an end wall of said bearing bush of said bearing for axially supporting said motor shaft.

28. The electric drive motor according to claim 17, wherein said pot base portion of said permanent magnet carrier is connected to said motor shaft by way of a press-fit connecting seat or a welded connection.

29. The electric drive motor according to claim 17, wherein an inner base wall of said pot base portion is formed with at least one radially extending channel, and said pot base portion has a hub in which said motor shaft is received, and at least one groove is formed on a hub inner wall of said hub, said groove being fluidically connected to said at least one channel to form a liquid overflow channel, such that a liquid may overflow between the one axial side of said permanent magnet carrier and the other axial side of said permanent magnet carrier.

30. The electric drive motor according to claim 17, wherein said pot base portion of said permanent magnet carrier is produced together with the circular cylinder wall portion of said permanent magnet carrier as an integral component by a process selected from the group consisting of machining, sintering, casting, deep-drawing, and deep-pressing.

31. The electric drive motor according to claim 17, wherein said pot base portion of said permanent magnet carrier is produced together with the circular cylinder wall portion of said permanent magnet carrier as an integral component, by said circular cylinder wall portion being formed from a tubular portion of a first semi-finished product and said pot base portion being formed from a stamped circular disk of a substantially plate-shaped semi-finished product, and said tubular portion being connected to said circular disk by welding or soldering to said integral component.

32. The electric drive motor according to claim 17, further comprising an impeller mounted to said seat formed on said first axial end portion of said motor shaft.

33. A wet-rotor pump, comprising: a pump chamber wall defining a wet chamber of the wet-rotor pump; an electric drive motor according to claim 17; and an impeller rotatably mounted in said wet chamber and supported on, and driven by, the motor shaft of said electric drive motor.

34. The wet-rotor pump according to claim 32, wherein said pump chamber wall is pot-shaped and has a pump chamber wall pot base formed with abutment surface that faces a front face of said second axial end portion of said motor shaft and which is configured for supporting said motor shaft in a direction opposing an axial bearing direction of said bearing.

35. A household appliance, comprising a wet-rotor pump according to claim 32 with an electric drive motor.

36. The household appliance according to claim 35 being a dishwasher, a washing machine, a dryer, or an extractor hood.

Description

[0045] Practical exemplary embodiments of an electric drive motor according to the invention are described in more detail in the following description with reference to the accompanying figures using the example of a wet-rotor pump which has such an electric drive motor. Specific individual features of these exemplary embodiments may represent general features of the invention irrespective of the actual context in which they are mentioned, optionally even individually or in different combinations from those shown.

[0046] In the drawings:

[0047] FIG. 1 shows a perspective view of an exemplary wet-rotor pump of a household appliance in the manner of a dishwasher which has an impeller and an electric drive motor;

[0048] FIG. 2 shows a sectional view of a wet-rotor pump according to the invention with an electric drive motor;

[0049] FIG. 3 shows an exploded view of a first exemplary embodiment of a permanent magnet rotor according to the invention of the electric drive motor according to FIG. 2;

[0050] FIG. 4 shows an exploded view of a second exemplary embodiment of a permanent magnet rotor according to the invention of the electric drive motor according to FIG. 2;

[0051] FIG. 5 shows a side view, a sectional view and an axial plan view of the permanent magnet carrier of the electric drive motor according to FIG. 2; and

[0052] FIG. 6 shows an axial plan view, a longitudinal sectional view and a cross sectional view of an exemplary assembly of the motor shaft, permanent magnet carrier and permanent magnet.

[0053] FIG. 1 to FIG. 6 show components of two exemplary embodiments of a wet-rotor pump 1 of an exemplary household appliance, for example a dishwasher. The wet-rotor pump 1 comprises a pump housing 2 and an electric drive motor 3.

[0054] As is shown in FIG. 2, in particular, the wet-rotor pump 1 has a pump chamber wall 2a which defines a wet chamber N of the wet-rotor pump 1, an impeller 10 which is rotatably mounted in the wet chamber N, and an electric drive motor 3 which drives the impeller 10 and which has a stator 5 with pole shoes 6 arranged outside the wet chamber N and at least one electrically actuatable stator winding 7, and which has a permanent magnet rotor 8 mounted in a rotatably drivable manner inside the wet chamber N in the field of the stator winding 7 leaving an annular gap R.

[0055] The permanent magnet rotor 8 comprises a motor shaft 11 on which both a permanent magnet carrier 9 of the permanent magnet rotor 8 and the impeller 10 are fastened, wherein the impeller 10 is fastened to a first axial end portion 11.1 of the motor shaft 11 and the permanent magnet carrier 9 is fastened to a second axial end portion 11.2 of the motor shaft 11 opposite the first end portion 11.1 of the motor shaft 11.

[0056] The motor shaft 11 is rotatably mounted by means of a bearing 12 inside the wet chamber N, which bearing 12 carries the motor shaft 11 on an intermediate portion 11.3 of the motor shaft 11 arranged axially between the first end portion 11.1 of the motor shaft 11 and the second end portion 11.2 of the motor shaft 11.

[0057] In the case of the present exemplary embodiment, a bearing seat 19 of a bearing shield 18 has a circular cylinder inner wall and a bearing bush 20 has a circular cylinder outer casing wall which corresponds to the circular cylinder inner wall of the bearing shield 18 and which is configured as shown such that the bearing bush 20 is inserted with a precise fit into the bearing seat 19.

[0058] The bearing shield 18 forms an intermediate wall which separates a first partial space N1 of the wet chamber N in which the permanent magnet carrier 8 is arranged, from a second partial space N2 of the wet chamber N in which the impeller 10 is arranged.

[0059] The permanent magnet carrier 9 is of pot-shaped configuration such that the permanent magnet carrier 9 has a pot base portion 9.1 via which the permanent magnet carrier 9 is fastened to the second axial end portion of the motor shaft 11 and the permanent magnet carrier 9 has a circular cylinder wall portion 9.2 which adjoins the pot base portion 9.1, which coaxially surrounds the motor shaft 11 and which defines a hollow space H of the permanent magnet carrier 9, the bearing 12 extending into said hollow space H.

[0060] The permanent magnet carrier 9 carries the at least one permanent magnet 13 and is fastened to a second axial end portion 11.2 of the motor shaft 11 opposite the first end portion 11.1 of the motor shaft 11. The motor shaft 11 is rotatably mounted by means of the bearing 12 inside the wet chamber N, wherein the permanent magnet carrier 9 is pot-shaped and has a pot base portion 9.1 fastened to the second axial end portion 11.2 of the motor shaft 11 and extending at least substantially radially to the motor shaft 11, and a circular cylinder wall portion 9.2 directly adjoining the outer periphery of the pot base portion 9.1 and coaxially surrounding the motor shaft 11, wherein the pot base portion 9.1 and the circular cylinder wall portion 9.2 have an at least approximately identical or exactly identical wall thickness.

[0061] At least the circular cylinder wall portion 9.2 of the permanent magnet carrier 9, or the entire permanent magnet carrier 9 comprising the pot base portion 9.1 and the circular cylinder wall portion 9.2, are produced from ferromagnetic material.

[0062] The circular cylinder wall portion 9.2 of the permanent magnet carrier 9, or the pot base portion 9.1 of the permanent magnet carrier 9, or the entire permanent magnet carrier 9 comprising the pot base portion 9.1 and the circular cylinder wall portion 9.2, may be produced from stainless steel, in particular magnetic stainless steel, a soft magnetic composite material, a sintered magnetic material and/or a soft magnetic plastic compound.

[0063] The at least one permanent magnet 13 is fastened to an outer peripheral casing wall of the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 by means of an adhesively bonded connection.

[0064] According to the embodiment according to FIG. 3, the permanent magnet rotor 8 has a plurality of individual permanent magnets 13a which are arranged so as to be distributed uniformly over a periphery, in particular circular arc-shaped permanent magnets 13b which are fastened to the outer peripheral casing wall 22 of the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 by means of an adhesively bonded connection.

[0065] According to an alternative embodiment according to FIG. 4, the permanent magnet rotor 8 has a single annular permanent magnet 13c which comprises a plurality of magnetic pole pairs and which is fastened to the outer peripheral casing wall 22 of the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 by means of an adhesively bonded connection.

[0066] The at least one permanent magnet 13 is accordingly fastened to the outer peripheral casing wall 22 of the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 by means of an adhesively bonded connection which, in particular, has a magnetically conductive adhesive.

[0067] Returning to FIG. 2 it is shown that the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 has an inner casing wall 23 which coaxially surrounds the motor shaft 11 and defines a hollow space H between the permanent magnet carrier 9 and the motor shaft 11, the bearing bush 20 of the bearing 12 extending into said hollow space H.

[0068] The pot base portion 9.1 of the permanent magnet carrier 9 also has an inner base wall 24 which forms an axial bearing surface which directly abuts against an end wall of the bearing bush 20 of the bearing 12 for axially supporting the motor shaft 11. Moreover, the pump chamber wall 2a is also configured to be pot-shaped with a pump chamber wallpot base 2b, wherein the pump chamber wallpot base 2b has an abutment surface A which faces the front face T of the second axial end portion 11.2 of the motor shaft 11 and which is configured for supporting the motor shaft 11 in a direction opposing the bearing direction of the axial bearing 17 and/or the axial bearing surface of the inner base wall 24.

[0069] The pot base portion 9.1 of the permanent magnet carrier 9 is connected to the motor shaft 11 by means of a press-fit connecting seat or a welded connection.

[0070] As is visible in particular in FIG. 5 and FIG. 6, in the case of the exemplary embodiment shown, three radially extending channels 14 are arranged on the inner base wall 24 of the pot base portion 9.1 of the permanent magnet carrier 9, and the pot base portion 9.1 has a hub 15 in which the motor shaft 11 is received, wherein in the case of the exemplary embodiment shown three grooves 16 are incorporated on the hub inner wall of the hub 15, said grooves being connected to the channels 14 in terms of flow technology to form liquid overflow channels, such that the liquid which is located in the wet chamber N may overflow between the one axial side of the permanent magnet carrier 9 and the other axial side of the permanent magnet carrier 9.

[0071] In FIG. 6 the channels 14 are oriented such that they extend outwardly in radial directions from the hub 15. The channels 14 in this case are configured to run in a linear manner. In contrast to FIG. 6, however, the channels 14 according to FIG. 5 are oriented such that they extend outwardly away from the hub 15. However, the channels 14 in the case of the embodiment according to FIG. 5 are not configured to run in a linear manner but are configured to run in a curved manner. According to FIG. 5 the curved path of the channels 14 may be such that in plan view, as shown to the left in FIG. 5, the channels extend in this plane which is located perpendicular to the rotational axis, as shown, and in this plane describe a curve or an arc. An arcuate path of the channels 14 may contribute to a reduction in noise during the rotation of the permanent magnet rotor 8.

[0072] The pot base portion 9.1 of the permanent magnet carrier 9 is produced, as shown, together with the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 as an integral component, for example by machining, by sintering, by casting, by deep-drawing and/or deep-pressing.

[0073] The pot base portion 9.1 of the permanent magnet carrier 9, however, may also be produced together with the circular cylinder wall portion 9.2 of the permanent magnet carrier 9 as an integral component, by the circular cylinder wall portion 9.2 being formed from a tubular portion of a first semi-finished product and the pot base portion 9.1 being formed from a stamped circular disk of a substantially plate-shaped second semi-finished product, and the tubular portion being connected to the circular disk by welding or soldering to form the integral component.

LIST OF REFERENCE CHARACTERS

[0074] 1 Wet-rotor pump

[0075] 2 Pump housing

[0076] 2a Pump chamber wall

[0077] 2b Pump chamber wallpot base

[0078] 3 Electric drive motor

[0079] 5 Stator

[0080] 6 Pole shoe

[0081] 7 Stator winding

[0082] 8 Permanent magnet rotor

[0083] Permanent magnet carrier

[0084] 9.1 Pot base portion

[0085] 9.2 Circular cylinder wall portion

[0086] 10 Impeller

[0087] 11 Motor shaft

[0088] 11.1 First axial end portion

[0089] 11.2 Second axial end portion

[0090] 11.3 Intermediate portion

[0091] 12 Bearing

[0092] 13 Permanent magnet

[0093] 13a Individual permanent magnets

[0094] 13b Circular arc-shaped permanent magnets

[0095] 13c Annular permanent magnet

[0096] 14 Channels

[0097] 15 Hub

[0098] 16 Grooves

[0099] 17 Axial bearing

[0100] 18 Bearing shield

[0101] 19 Bearing seat

[0102] 20 Bearing bush

[0103] 22 Outer peripheral casing wall

[0104] 23 Inner casing wall

[0105] 24 Inner base wall

[0106] A Abutment surface

[0107] H Hollow space

[0108] N Wet chamber

[0109] N1 First partial space

[0110] N2 Second partial space

[0111] R Annular gap

[0112] T Front face