AU2006235808A1

AU2006235808A1 - Intergrated washing machine pump

Info

Publication number: AU2006235808A1
Application number: AU2006235808A
Authority: AU
Inventors: Paul Gregory Hill
Original assignee: Fisher and Paykel Appliances Ltd
Current assignee: Fisher and Paykel Appliances Ltd
Priority date: 2005-11-04
Filing date: 2006-11-02
Publication date: 2007-05-24
Also published as: EP1783263A2; EP1783263A3; WO2007053041A1; CA2628450A1

Description

02-NOU-2006 12:04 A J PARK 64 9 3566990 P.06 1- Regulation 3.2

AUSTRALIA

PATENTS ACT, 1990 COMPLETE

SPECIFICATION

FOR A STANDARD

PATENT

ORIGINAL

Name of Applicant: FISHER PAYKEL APPLIANCES

LIMITED

Actual Inventor: PAUL GREGORY

HILL

Address for service A PARK, Level 11, 60 Marcus Clarke Street, Canberra

ACT

in Australia: 2601, Australia Invention Title: INTEGRATED WASHING MACHINE

PUMP

The following statement is a full description of this invention, including the best method of perrmng it known to us.

COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOU-2006 12:04 A J PARK 64 9 3566990 P.07 "INTEGRATED WASHING MACHINE

PUMP,

FIELD OF THE INVENTION This inventionrelates to clothes washing machines and in particular drain or recirculating pumps for such machines- BACKGROUND TO THE INVENTION Clothes washing machines require a pump to drain the machine bowl of both wash and rinse water. In machines where wash water is recirculated a pump is required for this purpose also.

Hitherto such pumps have taken the form of discrete components mounted outside the washing machine bowl and connected thereto by means of ducts and hoses.

The use of discrete component pumps in washing machines gives rise to the risk of water leakage because of the number of joints required between ducts, hoses and pumps and hose deterioration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an integrated washing machine and pump structure which will at least reduce the abovcmcntioned disadvantage.

Accordingly in one aspect the invention consists in a clothes washing machine comprising: a stationary watertight outer bowl which in use may selectively contain wash or rinse liquid, a perforated tub which receives the clothes load mounted within said outer bowl, means for selectively agitating or spinning the clothes load within said perforated tub, ,a rotary pump for pumping wash water or rinse water frorn said outer bowl, said pump havinga housing integrally formed in the wall of said outer bowl, a motor rotor rotatably mounted within said housing, an impeller mounted within said housing and connected to said rotor, said housing being open to the intcrior ofsaid outer bowl to provide an inlet to said purp, and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator.

In a second aspect the invention consists in a clothes washing machine comptisinga stationary outer bowl which in use may selectively contain wash or rinse liquid, 79 4872 J.-Dc COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOV-2006 12:04 A J PARK 64 9 3566990 P.08

O

0 0 -3cN

O

said outer bowl having an aperture in the bottom, O a perforated tub which receives the clothes load mounted within said outer bowl, means for selectively agitating or spinning the clothes load within said perforated tub, a rotary pump for pumping wash water or rinse water from said outer bowl, said pump having: Shousing which is sealably mounted within said aperture in said outer bowl to be integral a motor rotor rotatabty mounted within said housing, an impeller mounted within said housing and connected to said rotor, said housing being open to the interior of said outer bowl to provide an inlet to said pump, and motor taor being mounted about the exterior surfce of said hoing in co-acti rearionship with said rotor such that the housing wa lies between said rotor and said stator.

In a third aspect the invention consists in a pump for a clothes washing machine having a water containing outer bowl comprising: a housing adapted to be selably mounted within an aperture in said outer bowl, an electric motor rotor rotaably mounted within said housing, an impeler mounted within said housing and connected to said rotor, said housingin use being open to the interior of said outer bowl to provide an inlet to said pump, and a motor stator being mounted about the exterior surface of said housing in co-cting reationship with said rotor such that the housing wall lies between said rotor and said stator.

Preferably said rotor includes a drive shaft and said ipe is mounted on said drive shaft.

Preferably a tansverse partition is mounted in said housing which separates said rotor and said impeller into separate compartments and which supports a waterproof bearing in a central aperture through which said drive shaft passes and is journalled.

Pteferably said impeller is mounted within said housing proximate to said outer bowl and said rotor is mounted in said housing distal to said outer bowl.

preferably said partition has a small aperture therein to allow wash liquid to enter said rotor comparntment and to vent pneumatic pressure in said eompartment when hot.

Preferably a filter is mounted in said aperture to prevent foreign objects from entering said rotor compartment.

Preferably said distal portion of said housing has a cylindrical wall and said cylindrical wall lies between said stator and said rotor.

7 9 _872 .noc COMSID No: BMI-05231420 Received by P Australia: Time 10:08 Dte 200-11-02 02-NOU-2006 12:04 A J PARK 64 9 3566990 P.09 -4- 0 0

(O

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will now be described with reference to the N accompanying drawings in which: S 5 Figure diagrammaticlly shows a first embodiment ofa drain/recirculating pump integrated with a washing machine bowl, 0 Figure 2 shows a second embodiment of a drAn/reciru OO in/recirculating pump integrated with a 00 washing machine bowl, en Figure 3 shows an enlarged view of detail A in Figure 2, IQ tFigu e 4 shows an exploded pictorial view of a drain/recircuting pump to be integrated with a washing machine bowl, Figure 5 shows a cross-section through the pump of Figure 4.

DETAILED

DESCRIPTION

The essence of the present invention is the integration ofa drain/recirculation punp (preferably a ccnrrif-gal pump) with a washing machine bowl, thereby reducing the number of water connections outside the watertight bowl. One embodiment of the invention is illustrated diagrammatically in Figure 1.

A washing machine outer bowl 1 has a floor 2 into which is moulded a cylindrical recess 3 which forms part of the drain/recircultion pump housing. In particular a cylindrical recess 3 forms the lower portion of the pump housing and houses a rotor 4 of an electric motor (generally indicated as The motor stator 6 is mounted exteriorally of the washing machine bowl 2 about the cylindrical wall 14 of recess 3 so as to be co-axil and co-planar with rotor 4. The wall of the ump housing, which forms part of the outer bowl lies in the motor air gap. Motor 5 is preferably a brushless de motor with the windings of stator 6 commutated electronically.

Rotor 4 carries a drive shaft 7 which is connected to a pump impeller 8 which in turn is contained within th e too a puthe pe8hee i contained within the upper portion 9 of the pump housing. The pump housing 9 has an inlet 10 in the form of an opening to the interior of outer bowl I through which wash and rinse water may flow to be pressurised by iinpeler 8.

The pump outlet duct 1 extends from pump housing 9 within the outer bowl and terminates at a connector 12 to which a flexible hose 13 may be connected to convey drain water external to the bowl A recirculating outlet (not shown) feeds a pipe contained within the bowl, configured so as to discharge onto the clothes load.

79 48 72_1.DOC -4- COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOU-2006 12:05 A J PARK 64 9 3566990 o Exemplifying an advantage of the invention, in this embodiment it can be seen that there is only one potential leak path and that is at connection 12. Since that is located inside the bowl then o if the joint leaks the leakage remains within the watertight bowl 1. Some advantage could be ©c'i achieved by putting the pump inside the outer bowl and the entire drive motor outside it. Howevr, o 5 by also putting the rotor of the pump motor within the outer bowl the need for an aperture in the outer bowl and a dynamic shaft seal, with associated potential for leakage, is avoided.

A more easily fabricated embodiment will now bc described with reference to Figures 2 to 00(X Here the pUmp 19 is a separate part which is integrated with base 21 of a washing machine outer Mfl bowl 20 (see Figures 2 and The bowl is plastics moulded and is of the type disclosed in US ID 10 Patent 4,813,248. Within base 21 at a suitable drain point near a side wall of the bowl there is 0o moulded a drain sump and in the floor of the sump a flanged aperture 22 is provided. In the preferred form this is elliptical. Pump 19 is mounted In this aperture 22 and when mounted completely closes it off.

Referring in particular to Figures 4 and 5, the pump housing comprises a proximate portion 26 which houses a pump impeller 27 and a distal portion 28 which houses a rotor 29 of an electric motor 64 powering the pump. In the particular arrangement shown the housing connects to the bowl base with its axis substantially vertical. With this orientation the distal portion 28 of the housing is lower than the proximate portion which contains the impeller. The lower portion 28 of the pump housing is cylindrical and dosed off at the bottom with an integrally moulded floor section 30. The flange 48 of the pump housing 25 fits about the flange of the bowl aperture 22. A static sealing ring 50 which fits around the periphery of housing cap 42 seals the pump housing within the bowl aperture. The housing is fastened to the outer bowl by screws passing through lugs 47 provided about flange 48 of the upper porton 26 of the housing.

The pump is of the centrifgal type with impeller 27 configured so as to be capable of pumping when driven in either a clockwise or an anti-clockwise direction. The electic drive motor 64 is of the brushless permanent magnet DC type. The permanent magnet rotor 29 is rotatably mounted within the lower portion 28 of the pump housing. Rotor 29, which in the preferred embodiment may run wet (see below), rotates on a drive shaft 31 which connects to impeller 27. A partition member 33 (see in particular Figure 5) separates the upper and lower portions of the pump housing into an upper compartment 65 (containing the impeller) and a lower compartment 66 (containing the rotor) and provides a support for an upper bearing 34 within which drive shaft 31 is journalled. Partition 33 together with dynamic shaft seal ptevents materials entrained in the machine wash or rinse water from entering the lower compartment 66 of the pump housing to thereby cause 79 4 8 72-DOc COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 2-NOU-20066 12:05 A J PARK 64 9 3566990 P.11 -6-

O

0o wear or jamning of the rotor. However a small aperture 60 is provided in partition member 33 to allow controlled water flow into the lower compartment of the pump housing. The presence of water assists in cooling and lubricating the rotor and bearings 61 and 34. Aperture 60 is preferably Sprovided with a filter (not shown) to exclude particulte matter or other foreign bodies from entering the motor rotor compartment 66. Aperture 60 also vents pneumatic pressure in the rotor compartment when hot.

S Rotor drive shaft 31 is also journalled in a lower beating 61 which is supported in a cavity 62 0 in the floor 30 of the pump housing. The motor stator 35 is mounted on the exterior of the pump ci housing co-axially with the rotor and in the same principal plane as the rotor about the lower portion 28 of the pump housing. The cylindrical walls of the lower portion of the pump housing 0 reside within the "air gap" between the rotor and stator. The stator may typically be of the salient pole type preferably having six poles 36. The stator, being external to the pump housing, is in a dry environment notwithstanding the rotor part of the motor is contained within the pump housing and therefore in essence within the washing machine bowl. The stator is protected by a plastics cover 37 which has a removable base 38 held in place by screws 63.

The stator 35 comprises substantially annular laminations of magnetic steel which are over moulded with a plastics case which also covers the integrally formed poles to provide plastic bobbins around which the windings 36 are wound. The pole tips are arcuate and lie on a circle of a diameter equal to the outer diameter of the cylindrical wall of the lower portion of the pup housing. The stator is camped in place by base 38.

The brushless DC motor preferably has a controller which uses the back EMF induced in an unused stator winding to provide the necessary rotor position sensing. Controllers of the type suitable for the present motor are disclosed in US 6,034,493 and WO 2005/062460.

Instead of back EMF sensing of the rotor position other known techniques can be used such as Hall effect sensing.

In operation water pressurised by the centrifugal forces induced by rotation of impeller 27 leaves the upper portion of the pump housing through either outlet 40 to which is connected a drain hose or through outlet 39 into a recirculation duct (not shown) which guides the water back onto the top of the clothes load. Whether the water is drained or recirculated is determined by the direction in which impeller 27 is rotated. Mounted in association with impeller 27 is a bi-state flapper valve 41 which depending on the direction in which water leaves impeller 27 revolves between one of two states. In one state valve 41 seals off outlet 39 and water is directed to drain outlet 40 and in the other state water is directed to the recirculation outlet 39.

79 48 72

DOC

-6- COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOU-2006 12:05 A J PARK 64 9 3566990 P.12 -7- 0 O It is necessary to direct water from drain sump 23 in an efficient manner into the pump housing while at the same time ensuring that foreign objects ate prevented from entering the pump, 0 and also minimising the potential for blockage by clothes lint These objectives are met by the use Sof a top cap 42 in association with a complementary pump hood 43 which define the water inlet path to the pump. Water from the drain sump enters under the hood and over the top of the scalloped peripheral wall 44 of top cap 42 (which fonrms a first weir) and into the cap inlet aperture 00 45 defined by cylindrical wall 46 which forms a second wer.

0l A drain/recirculating pump integrated with a washing machine outer bowl in the manner disclosed ensures a water handling system with reduced leak paths external to the bowl.

NO

794872_J.DOC -7- COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02

Claims

02-NOJ-2006 12:06 A J PARK 64 9 3566990 P.13 -8- 0 0 CLAIMS ci 0 A clothes washing machine comprising: a 8atinay wterigt Oterbol wic z a stationary watertight outer bowl which in use "nay selectively contain wash or rinse liquid. 0 a perforated tub which receives the clothes load mounted within said outer bowl, Smeans for selectively agitating or spinning the clothes load within said perforated tub, 0a rotary pump for pumping wash water or rinse water from said outer bowl, said pump 0 having: V) M a housing ntegrally formed in the wall of said outer bowl, I 10 a motor rotor rotarably mounted within said housing, 0 0 an impeller mounted within said housing and connected to said rotor, said housing being open to the interior of said outer bowl to provide an inlet to said pump, and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator. 2. A clothes washing machine comprising: a stationary outer bowl which in use may selectively contain wash or rinse liquid, said outer bowl having an aperture in the bottom, a perforated tub which receives the clothes load mounted within said outer bowl, means for selectively agitating or spinning the clothes load within said perforated tub, a rotary pump for pumping wash water or rinse water from said outer bowl, said pump having: a housing which is sealably mounted within said aperture in said outer bowl to be integral with said outer bowl, a motor rotor rotatably mtounted within said housing, an impeller mounted within said housing and connected to said rotor, said housing being open to the interior of said outer bowl to provide an inlet to said pump, and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator.
3. A pump for a clothes washing machine having a water containing outer bowl which drains and/or recirculates liquid in said bowl, said bowl having an aperture in the bottom and said pump having a housing which includes an electric motor, comprising: 794872 J.D OC COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOU-2006 12:06 A J PARK 64 9 3566990 P.14 -9- 0a housing adapted to be sealably mounted within an aperture in said outer bowl, an electric motor rotor rotatably mounted within said housing, an impeller mounted within said housing and connected to said rotor, said housing in use being open to the interior of said outer bowl to provide an inlet to said oo prvd nineosi pumnp, and a motor stator being mounted about the exterior surface of said housing in co-acting 00O relationship with said rotor such that the housing wall lies between said rotor and said stator. 0 00 Mn
4. A clothes washing machine according to either of claims I or 3 wherein said rotor includes a Ni 10 drive shaft and said impeller is rnountcd on said drive shaft. 0 ci
5. A clothes washing machine according to daim 4 wherein a transverse partition is mounted in said housing which separates said rotor and said impeller into two compartments and which contains a waterproof bearing in a central aperture through which said drive shaft passes and is journalled.
6. A clothes washing appliance according to claim 5 wherein said impeller is mounted within said housing proximate to said outer bowl and said rotor is mounted in said housing distal to said outer bowl-
7. A clothes washing appliance according to clahim 6 wherein said partition has a small aperture therein which allows wash liquid to enter the rotor compartment and to vent pneumatic pressure in said rotor comopartment.
8. A clothes washing appliance according to claim 7 wherein a filtcr is located in said aperture to prevent foreign bodies entrained in said wash liquid from entering said rotor compartment.
9. A clothes washing appliance according to any one of the preceding claims wherein said distal portion of said housing has a cylindrical wall and said cylindrical wall lics between said stator and said rotor. A clothes washing machine as claimed in any one of the preceding claims wherein said pump motor is a brushless dc motor. 79472_,LM -9- COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02 02-NOV-2006 12:06 A J PARK 64 9 3566990 O 0 00 00 c
11. A clothes washing machine substantially as heteinbefore described with reference to Figure 1 o 5 12 A clothes washing machine substantially as hereinbefore described with reference to Figures 00 O 00
791871.DO COMS ID No: SBMI-05231420 Received by IP Australia: Time 10:08 Date 2006-11-02