DE202024100525U1 - Canned motor and wet rotor electric pump hereby - Google Patents

Abstract

Multiphase BLDC canned motor (5) for a household appliance pump comprising a shaft (6) extending longitudinally in an axial direction (7), a rotor (9) held on the shaft (6) in a rotationally fixed manner with a permanent magnet (10) and a stator (11) enclosing the rotor (9) in a circumferential direction, wherein the stator (11) provides a stator laminated core (12), a plurality of coil carriers (13) and a plurality of coils (14), comprising a can (20) made of a glass fiber reinforced plastic that can be filled with a liquid surrounding the rotor (9), with a canned pot (22) and a canned pot flange (21), wherein the canned pot (22) provides a canned pot casing (23) extending longitudinally in the axial direction (7) and a canned pot base (24), wherein the canned pot casing (23) is located in a space between the rotor (9) and the stator (11) formed functional gap, wherein the split tube base (24) adjoins the split tube casing (23) at a first end thereof and wherein the split tube flange (21) protrudes outwardly from the split tube casing (23) at a second end of the split tube casing (23) opposite the split tube base (24), and comprising a bearing carrier (40) made of a glass fiber reinforced plastic, wherein the bearing carrier (40) is inserted into a bearing carrier receptacle (29) of the split tube (20), which is formed in a transition region between the split tube pot (22) and the split tube flange (21), wherein the shaft (6) with a jacket surface thereof lies directly against a first support surface (26) of a first bearing seat (25) on the one hand and directly against a second support surface (44) of a second bearing seat (43) on the other hand, wherein the first bearing seat (25) is formed in the split tube base (24) and the bearing carrier (40) the second bearing seat (43) with the second support surface (44).

Description

The invention relates to a canned motor for a household appliance pump. Furthermore, the invention relates to a wet-running electric pump with a canned motor.

A wet rotor electric pump with a canned motor is, for example, from the EN 10 2012 203 615 A1 The wet rotor electric pump is used in particular for pumping liquids in water-conducting household appliances.

The object of the present invention is to provide an improved canned motor and an improved wet-running electric pump.

To solve the problem, the invention has the features of claim 1. Accordingly, a multi-phase BLDC canned motor for a household appliance pump comprises a shaft extending longitudinally in an axial direction, a rotor held on the shaft in a rotationally fixed manner with a permanent magnet and a stator enclosing the rotor in a circumferential direction. The stator provides a stator laminated core, a plurality of coil carriers and a plurality of coils. The multi-phase BLDC canned motor comprises a can made of a glass fiber reinforced plastic, which can be filled with a liquid surrounding the rotor. The can provides a can pot and a can flange, wherein the can pot has a can shell extending longitudinally in the axial direction and a can base. The can shell extends in a functional gap formed between the rotor and the stator. The can base adjoins the can shell at a first end of the can. The split tube flange projects outward from the split tube shell at a second end of the split tube shell opposite the split tube bottom.

The multi-phase BLDC canned motor further comprises a bearing carrier made of a glass fiber reinforced plastic. The bearing carrier is inserted into a bearing carrier holder of the can, which is formed in a transition area between the can pot and the can flange.

The shaft of the multi-phase BLDC canned motor rests with its outer surface directly on a first support surface of a first bearing seat on the one hand and directly on a first support surface of a second bearing seat on the other hand, with the first bearing seat being formed in the canned base and the bearing carrier in the second bearing seat providing the second support surface. The invention dispenses with the usually provided bearings, in particular plain bearings or roller bearings, by means of which the shaft is supported in the bearing seats. The multi-phase BLDC canned motor is therefore designed as a bearingless multi-phase BLDC canned motor.

The particular advantage of the invention is that the multi-phase BLDC canned motor can be implemented very cost-effectively. This is helped by the fact that by dispensing with the bearings, components can be saved and the material and parts costs are reduced. At the same time, the assembly and testing effort is reduced by dispensing with the bearings. The bearing points are formed directly during the manufacture of the can and the bearing carrier using the injection and casting process. Testing of the multi-phase BLDC canned motor has shown that the tolerance specifications can also be reliably met by minimizing the tolerance chain associated with dispensing with the bearings. Concentricity is improved and the service life increased. Testing has shown that a service life of far more than the 1000 operating hours typical for the application is reliably achieved and thus significantly exceeded.

The favorable service life values are also achieved because the multi-phase BLDC canned motor, unlike commonly used single-phase synchronous motors, provides a circular rotating field, which contributes to a lower load on the bearings. The lower bearing load reduces friction in the bearing points and thus wear, which in turn has a positive effect on operating noise and service life.

In addition, the use of glass fiber reinforced plastic has proven to be very beneficial. The glass fiber content of the injection molding material for the can, which serves as the B-side bearing of the shaft, and the bearing carrier serving as the A-side bearing of the shaft has a positive influence on the temperature development during operation and the heat resistance of the bearing point.

According to a preferred embodiment of the invention, a plurality of slots distributed in the circumferential direction are provided on the first support surface of the first bearing seat. The slots preferably extend in the axial direction and are then designed as longitudinal slots. In particular, the longitudinal slots are designed and arranged in such a way that the canned liquid reaches the longitudinal slots. Particularly preferably, the longitudinal slots can be extended in such a way that they are at least in an operating state of the BLDC canned motor in which the rotor rotates and, as a result of the forces acting between the rotor and the stator during rotation, the rotor is rotated in the direction of the bearing carrier, the longitudinal slots extend beyond one end of the shaft and thus make it possible for the canned liquid to pass through the longitudinal slots and get behind the shaft. The provision of the liquid in the filled slot advantageously serves to cool the bearing point and to further reduce friction in the bearing points, which further increases the service life.

According to a development of the invention, the bearing carrier provides at least one axial passage and preferably a plurality of axial passages distributed in the circumferential direction. The at least one axial passage serves for the exchange of fluid between a can interior and an adjacent or adjacent pump chamber. The bearing carrier separates the can interior from the adjacent pump chamber. The axial passages make it possible for the working fluid pumped by the household appliance pump, for example a washing or soap solution, to reach the can interior and serve as can fluid. In the operating state of the BLDC canned motor, the fluid exchange ensures effective cooling or removal of the heat generated during operation. At the same time, a seal between the can interior and the pump chamber and a separate filling of the can interior with, for example, oil as can fluid can can be dispensed with.

According to a further development of the invention, a length of the first bearing seat determined in the axial direction and/or a length of the second bearing seat determined in the axial direction is at least five and at most ten millimeters. A bearing point designed in this way advantageously ensures secure guidance of the shaft and good and even distribution of the inner bearing point. At the same time, bearing points of this size can be manufactured with sufficient precision from glass fiber reinforced plastic using the injection molding process.

According to a further development of the invention, the glass fiber content in the glass fiber reinforced plastic of the split tube or the bearing support is at least 20% by weight and preferably at least 40% by weight. A correspondingly designed split tube or a correspondingly designed bearing support have very good properties in terms of temperature and heat resistance.

In particular, it can be provided that the bearing carrier on the one hand and the can on the other hand are made of the same glass fiber reinforced plastic and have an equal proportion of glass fibers.

According to a further development of the invention, the permanent magnet of the rotor is provided as a ring magnet and preferably as a one-piece ring magnet with a plurality of poles. The ring magnet shape facilitates a simple rotor construction. In addition, the ring magnet can be very easily attached to the shaft, in particular with an overmolding.

According to a further development of the invention, the stator has three, six, nine or twelve teeth. The permanent magnet is preferably designed with two, four, six, eight, ten, twelve, 14 or 16 poles. The selection of a suitable motor topology in combination with the circular rotating field of the multi-phase BLDC canned motor will advantageously reduce the bearing load. In addition, the speed of the multi-phase BLDC canned motor can be adjusted to suit requirements over a wide range. Depending on the motor topology, a speed in the range of 4,500 to 36,000 revolutions per minute can be achieved, for example, at an operating frequency of 600 Hz.

According to a further development of the invention, it is provided that the stator has six teeth and the permanent magnet has two or four or eight or ten poles, or that the stator has twelve teeth and the permanent magnet has two or four or eight or ten or 14 or 16 poles, or that the stator has nine teeth and the permanent magnet has six or twelve poles. Such motor topologies advantageously lead to the radial forces in the motor canceling each other out nominally. This promotes smooth running and reduces wear in the bearings, so that the service life is further improved.

According to a further development of the invention, the coil carriers of the stator are manufactured by overmolding the stator sheets and are formed as a single piece. This advantageously reduces the manufacturing costs and the assembly effort is further reduced.

To achieve the object, the invention has the features of claim 9. The wet-running electric pump provides a multi-phase BLDC canned motor according to the invention and a pump wheel which is held in a rotationally fixed manner on a shaft of the BLDC canned motor.

The multiphase BLDC canned motor according to the invention is preferably used as an electric drive for a wet-running electric pump consisting of a circulation pump and/or electric pump for pumping a liquid in a water-conducting household appliance. , especially a dishwasher or a washing machine.

Further advantages, features and details of the invention can be found in the further subclaims and the following description. The features mentioned there can be essential to the invention individually or in any combination. Features and details of the canned motor described in accordance with the invention naturally also apply in connection with the wet-running electric pump and its use. The disclosure of the individual aspects of the invention can therefore always be referred to reciprocally.

• 1 einen Längsschnittdarstellung einer erfindungsgemäßen Nassläuferelektropumpe mit einem erfindungsgemäßen mehrphasigen BLDC-Spaltrohrmotor,
• 2 eine perspektivische Widergabe eines Spaltrohrs des mehrphasigen BLDC-Spaltrohrmotors nach 1 mit einem hierein eingesetzten Lagerträger in einem Längsschnitt,
• 3 eine perspektivische Wiedergabe des Spaltrohr nach 2 und
• 4 eine perspektivische Wiedergabe des Lagerträgers nach 2.

The drawings serve only as examples to clarify the invention and are not restrictive in nature. They show:

• 1 a longitudinal sectional view of a wet-running electric pump according to the invention with a multiphase BLDC canned motor according to the invention,
• 2 a perspective representation of a can of the multiphase BLDC canned motor according to 1 with a bearing carrier inserted into it in a longitudinal section,
• 3 a perspective reproduction of the split tube according to 2 and
• 4 a perspective reproduction of the bearing carrier according to 2 .

A wet-running electric pump 1 according to the invention comprises a multiphase BLDC canned motor 5 according to the invention with a shaft 6 extending longitudinally in an axial direction 7 and a pump wheel 2, which is held at the end on the shaft 6 in a rotationally fixed manner. The pump wheel 2 is used to pump a liquid in a water-conducting household appliance, in particular a dishwasher or a washing machine. The liquid is typically a washing solution or soap solution.

The pump wheel 2 of the wet-running electric pump 1 is located in a pump chamber of the wet-running electric pump 1. The pump chamber is defined by a pump housing (not shown in the drawings) which is attached to a can 20 of the canned motor 5. For this purpose, a seal (not shown in the drawings) is provided on the can 20 of the canned motor 5, which seals the pump housing against the can 20. The can 20 has a seal seat 30 to accommodate the seal. The seal can be secured against rotation by suitable locking means (not shown in the drawings). Recesses (not shown) into which the locking means engage can then also be provided on the seal seat 30 of the can 20 or adjacent thereto.

The multi-phase BLDC canned motor 5 provides a rotor 9 with a multi-pole permanent magnet 10. The permanent magnet 10 is overmolded with a plastic and is held to the shaft 6 in a rotationally fixed manner by the overmold and is aligned coaxially with respect to a longitudinal center axis 8 to the shaft 6. As an example, the permanent magnet 10 is formed in one piece as a ring magnet.

The multi-phase BLDC canned motor 5 further comprises a stator 11 with a stator laminated core 12, with a plurality of coil carriers 13 and a plurality of coils 14 that surround the coil carriers 13. The coil carriers 13 are supported by teeth of the stator 11. The number of teeth of the stator 11 corresponds to the number of coil carriers 13 and the number of coils 14. A motor housing 16 surrounds the stator 11, at least in sections. By way of example, the coil carriers 13 in the illustrated embodiment of the invention are produced by overmolding the stator laminated core 12 and are formed in one piece.

The stator 11 surrounds the rotor 9 in the circumferential direction and a gap is formed between the stator 11 and the rotor 9 for functional reasons. A cylindrical can casing 23 extends into this functional gap between the stator 11 and the rotor 9 and is designed as part of a can casing 22 of the can casing 20. The can casing 22 also provides a can base 24 which adjoins the can casing 23 at a first end thereof.

The split tube 20 provides a split tube flange 21 next to the split tube pot 22. The split tube flange 21 adjoins the split tube casing 23 of the split tube pot 22 at a second end opposite the split tube base 24 and protrudes outward from the split tube casing 23. The split tube flange 21 provides the seal seat 30 for the seal (not shown).

The multi-phase BLDC canned motor 5 further comprises a bearing support 40. In the assembled state of the multi-phase BLDC canned motor 5, the bearing support 40 is arranged coaxially to the longitudinal central axis 9 and is designed to be point-symmetrical. It provides a radially extended disk 42, i.e. oriented perpendicular to the longitudinal central axis 8, as well as a collar 41 extending to the outer edge of the disk 42 in the axial direction 7. Furthermore, in the area of the disk 42 A total of 6 axial passages 45 are designed as an example.

The can 20 and the bearing carrier 40 are each made in one piece from the same glass fiber reinforced plastic by injection molding.

A rotor assembly of the wet-running electric pump 1 comprising the shaft 6, the rotor 9 and the pump wheel 2 is supported by a first bearing seat 25 and a second bearing seat 43. The first bearing seat 25 is formed concentrically to the longitudinal center axis 8 on the can base 24. The second bearing seat 43 is also formed concentrically to the longitudinal center axis 8 on the disk 42 of the bearing carrier 40.

The first bearing seat 25 and the second bearing seat 43 each provide a first support surface 26 and a second support surface 44, against which the shaft 6 rests directly with its outer surface. The multi-phase BLDC canned motor 5 according to the invention dispenses with plain bearings or roller bearings, which are usually arranged between a shaft and a bearing seat of a motor. In this respect, it is designed as a bearingless multi-pole BLDC canned motor. In relation to the axial direction 7, the first bearing seat 25 and the second bearing seat 43 have an axial length in the range of 5 to 10 mm.

The bearing carrier 40 is inserted into the can 20 of the multi-phase BLDC canned motor 5. For this purpose, an annular bearing carrier receptacle 29 is formed on the can 20 in a transition area between the can flange 21 and the can pot 22. The bearing carrier 40 is supported with the collar 41 against the bearing carrier receptacle 29 or is placed against it.

Between the collar 41 and the bearing support receptacle 29, a locking mechanism is provided, which is formed by a circumferential groove in the area of the bearing support receptacle 29 and a circumferential annular bead on the collar 41. In the assembled state, the annular bead engages in the groove. The locking mechanism serves to position the bearing support 40 relative to the can 20.

The canned pot 22 defines, with the cylindrical canned casing 23 and the canned base 24, a canned interior 28 which is separated from the pump chamber of the wet-running electric pump 1 by the disk 42 of the conductor carrier 40. The axial passages 45 of the bearing carrier 40 serve to exchange fluid between the canned interior 28 and the adjacent pump chamber. In this case, the canned interior 28 is filled with the washing or soap solution, which serves as the canned fluid.

In a non-operating state, the rotor assembly is positioned in the axial direction 7 relative to the stator 11 of the multi-phase BLDC canned motor 5 by the magnetic forces acting between the permanent magnet 10 and the stator 11. In an operating state of the BLDC canned motor 5, in which the rotor 9 rotates with the shaft 6 and the pump wheel 2, the rotor assembly is moved from the non-operating position in the direction of the bearing carrier 40 as a result of a hydraulic force acting in the axial direction 7. A thrust washer 15, which is arranged between a front side of the rotor 9 facing the bearing carrier 40 and the bearing carrier 40 itself, serves to space the rotor 9 from the bearing carrier 40 in the operating state.

The first bearing seat 25 provides a total of three longitudinal slots 27 in the area of the first support surface 26, which are regularly spaced and distributed in the circumferential direction. The longitudinal slots 27 extend longitudinally in the axial direction 7 and are designed, dimensioned and arranged such that the canned liquid gets into the longitudinal slots and serves to reduce friction and/or cool the first bearing seat during operation. The length of the longitudinal slots 27 in the axial direction is dimensioned such that, at least in the operating state of the BLDC canned motor 5, the longitudinal slots protrude beyond a functional end of the shaft 4 such that the canned liquid passes through the longitudinal slots 27 and gets behind the shaft 4.

List of reference symbols

1

Wet rotor electric pump

2

Impeller

5

Canned motor

6

Wave

7

Axial direction

8th

Longitudinal center axis

9

rotor

10

Permanent magnet

11

stator

12

Stator lamination package

13

Coil carrier

14

Winding

15

Thrust washer

16

Engine housing

20

split tube

21

Split tube flange

22

Split tube pot

23

Split tube casing

24

Split tube floor

25

Bearing seat

26

Support surface

27

Longitudinal slot

28

Can interior

29

Bearing carrier holder

30

Seal seat

40

Bearing carrier

41

collar

42

disc

43

Bearing seat

44

Support surface

45

Axial passage

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102012203615 A1 [0002]

Claims (10)

Multiphase BLDC canned motor (5) for a household appliance pump comprising a shaft (6) extending longitudinally in an axial direction (7), a rotor (9) held on the shaft (6) in a rotationally fixed manner with a permanent magnet (10) and a stator (11) enclosing the rotor (9) in a circumferential direction, wherein the stator (11) provides a stator laminated core (12), a plurality of coil carriers (13) and a plurality of coils (14), comprising a can (20) made of a glass fiber reinforced plastic that can be filled with a liquid surrounding the rotor (9), with a canned pot (22) and a canned pot flange (21), wherein the canned pot (22) provides a canned pot casing (23) extending longitudinally in the axial direction (7) and a canned pot base (24), wherein the canned pot casing (23) is located in a space between the rotor (9) and the stator (11) formed functional gap, wherein the split tube base (24) adjoins the split tube casing (23) at a first end thereof and wherein the split tube flange (21) protrudes outwardly from the split tube casing (23) at a second end of the split tube casing (23) opposite the split tube base (24), and comprising a bearing carrier (40) made of a glass fiber reinforced plastic, wherein the bearing carrier (40) is inserted into a bearing carrier receptacle (29) of the split tube (20), which is formed in a transition region between the split tube pot (22) and the split tube flange (21), wherein the shaft (6) with a jacket surface thereof lies directly against a first support surface (26) of a first bearing seat (25) on the one hand and directly against a second support surface (44) of a second bearing seat (43) on the other hand, wherein the first bearing seat (25) is formed in the split tube base (24) and the bearing carrier (40) the second bearing seat (43) with the second support surface (44). BLDC canned motor (5) according to Claim 1 , characterized in that a plurality of slots arranged distributed in the circumferential direction are provided on the first support surface (26) of the first bearing seat (25), wherein the slots preferably extend in the axial direction (7) and are designed as longitudinal slots (27) which, at least in an operating state of the BLDC canned motor (5), extend beyond one end of the shaft (4) and/or are designed and arranged such that the canned liquid gets into the longitudinal slots (27) and/or gets behind the shaft (4) through the longitudinal slots (27). BLDC canned motor (5) according to Claim 1 or 2 , characterized in that the bearing carrier (40) provides at least one axial passage (45), wherein the at least one axial passage (45) is designed to provide a fluid exchange between a can interior (28) and an adjacent pump chamber. BLDC canned motor (5) according to one of the Claims 1 until 3 , characterized in that a length of the first bearing seat (25) determined in the axial direction (7) and/or a length of the second bearing seat (43) determined in the axial direction (7) is at least 5 mm and is preferably not greater than 10 mm. BLDC canned motor (5) according to one of the Claims 1 until 4 , characterized in that a proportion of glass fiber in the glass fiber reinforced plastic of the split tube (20) and/or the bearing carrier (40) is at least 20% by weight and preferably at least 40% by weight. BLDC canned motor (5) according to one of the Claims 1 until 5 , characterized in that the bearing carrier (40) and the can (20) are made of the same glass fiber reinforced plastic. BLDC canned motor (5) according to one of the Claims 1 until 6 , characterized in that a ring magnet and preferably a one-piece ring magnet with a plurality of poles is provided as the permanent magnet (10). BLDC canned motor (5) according to one of the Claims 1 until 7 , characterized in that the stator (11) provides three or six or nine or twelve teeth carrying the coil carriers (13) and/or that the permanent magnet (10) is designed with two or four or six or eight or ten or twelve or 14 or 16 poles. Wet rotor electric pump (1) with a multiphase BLDC canned motor (5) according to one of the Claims 1 until 8th and with a pump wheel (2), wherein the pump wheel (2) is held in a rotationally fixed manner on a shaft of the BLDC canned motor (5). Use of a multiphase BLDC canned motor (5) according to a Claims 1 until 8th as an electric drive of a wet-running electric pump (1) used as a circulation and/or drain pump for pumping a liquid in a water-conducting household appliance, in particular in a dishwasher or a washing machine.

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