US20160265151A1 - Washing machine with direct drive motor and method for its manufacture - Google Patents
Washing machine with direct drive motor and method for its manufacture Download PDFInfo
- Publication number
- US20160265151A1 US20160265151A1 US15/065,454 US201615065454A US2016265151A1 US 20160265151 A1 US20160265151 A1 US 20160265151A1 US 201615065454 A US201615065454 A US 201615065454A US 2016265151 A1 US2016265151 A1 US 2016265151A1
- Authority
- US
- United States
- Prior art keywords
- tub
- stator assembly
- washing machine
- plastic
- protruding portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/20—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations
- D06F37/206—Mounting of motor
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/26—Casings; Tubs
- D06F37/261—Tubs made by a specially selected manufacturing process or characterised by their assembly from elements
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/26—Casings; Tubs
- D06F37/261—Tubs made by a specially selected manufacturing process or characterised by their assembly from elements
- D06F37/262—Tubs made by a specially selected manufacturing process or characterised by their assembly from elements made of plastic material, e.g. by injection moulding
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/26—Casings; Tubs
- D06F37/267—Tubs specially adapted for mounting thereto components or devices not provided for in preceding subgroups
- D06F37/269—Tubs specially adapted for mounting thereto components or devices not provided for in preceding subgroups for the bearing of the rotary receptacle
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/30—Driving arrangements
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/26—Casings; Tubs
- D06F37/264—Tubs provided with reinforcing structures, e.g. ribs, inserts, braces
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
- D06F37/30—Driving arrangements
- D06F37/304—Arrangements or adaptations of electric motors
Definitions
- the present invention relates to a washing machine with a direct drive motor system comprising a tub, a drum rotatably mounted inside the tub, and a shaft connected to the drum for transmitting a driving torque of said direct drive motor system, this latter comprising a rotor assembly fastened to the shaft and a stator fastened to the tub.
- a direct drive motor system comprising a tub, a drum rotatably mounted inside the tub, and a shaft connected to the drum for transmitting a driving torque of said direct drive motor system, this latter comprising a rotor assembly fastened to the shaft and a stator fastened to the tub.
- EP 2626459 discloses a washing machine having a direct drive motor where the stator comprises fixing pins inserted into the rear wall of the tub. The use of pins and holes make the overall construction of the washing machine more complex.
- EP 1580311 discloses a direct drive motor where the stator is centered by means of a cylindrical or conical protuberance which enters the bearing hole which is precisely machined in order to seat ball bearings. This known solution requires to reduce the axial distance of the ball bearings, with a direct impact on the rigidity of the drum shaft support, or to increase the axial dimension of the central portion of the bearing spider. Moreover the solution disclosed by EP 1580311 is not for washing machine having a plastic tub, since it is clearly fit for washing machines having a metal tub.
- DE 10060940 discloses a washing machine which, similarly to EP 1580311, uses a metal bearing spider which cooperates with an axial protrusion of the stator during reciprocal engagement. Metal surface of the bearing spider has to be precisely machined in order to properly center the stator.
- a washing machine with a direct drive motor system includes a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving torque of a direct drive motor.
- the motor includes a rotor assembly fastened to the shaft and a stator assembly fastened to the tub.
- the plastic tub has a central protruding portion where a central opening of the stator assembly is centered before its final fastening to the tub.
- the central opening of the stator assembly presents a plurality of centering surfaces configured to cooperate with an outside cylindrical surface of the central protruding portion of the tub.
- a method for producing a washing machine with a direct drive motor system where the washing machine includes a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving force of a direct drive motor, and the motor has a rotor assembly fastened to the shaft and a stator assembly fastened to the tub.
- the method includes co-injecting the plastic tub on a metal reinforcing element which acts also as a central hub so that a central protruding plastic portion is created as a plastic layer on one end of the hub.
- the stator assembly axially slides on the plastic layer in order to center the stator assembly.
- a plurality of centering surfaces provided on the central opening of the stator assembly cooperates with an outside cylindrical surface of the central protruding portion of the tub during the axially sliding.
- the centering of the stator on the tub is made by using only specific centering surfaces of the stator provided on the edge of the central opening used for its assembly to the protruding portion of the tub.
- FIG. 1 is a cross longitudinal section of the rear wall of a tub of a washing machine according to the invention, in which the direct drive motor system is installed.
- FIG. 2 is an enlarged detail of FIG. 1 .
- FIG. 3 is a detail of a front view of the rear wall of the tub, where the rotor has been removed.
- a direct drive washing machine comprises a plastic tub 10 whose rear wall 10 a presents a reinforcing star-shaped metal element 12 which forms also a central hub 12 a for mounting ball bearings 14 .
- Such bearings 14 are used supporting a shaft 16 supporting a drum 18 .
- the rear wall 10 a of the plastic tub 10 presents an axial rear protrusion 20 having a first portion 20 a slightly tapered and a second portion 20 b which is cylindrical and whose diameter corresponds exactly to the diameter of a circumference defined by three centering curved surfaces 22 formed on an edge 22 a of a central hole of a stator 24 .
- cup-shaped rotor 26 is mounted on one end 16 a of the shaft 16 opposite the drum 18 .
- the rear wall 10 a of the tub presents, on its axial protrusion 20 a radial extension 28 ( FIG. 3 ) which corresponds to a radial seat 30 of the stator 24 .
- first step is to insert the stator 24 on the axial protrusion 20 of the tub, so that centering surfaces 22 slide first on the tapered portion 20 a for a pre-centering operation and then it slides on a cylindrical smooth surface 21 of a portion 20 b for a final centering operation, such movement ending when the stator 24 abuts the rear wall 10 a of the tub 10 . Then the stator 24 , perfectly centered on the tub 10 , is fixed in a known way by means of screws 32 .
- Next and final step is to install the rotor 26 on the end 16 a of the shaft 16 .
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Main Body Construction Of Washing Machines And Laundry Dryers (AREA)
- Manufacture Of Motors, Generators (AREA)
Abstract
A washing machine with a direct drive motor system includes a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving torque of a direct drive motor. The motor has a rotor assembly fastened to the shaft and a stator assembly fastened to the tub. The plastic tub includes a central protruding portion where a central opening of the stator assembly is centered before it is fastened to the tub, the central opening of the stator assembly presenting a plurality of centering surfaces configured to cooperate with an outside cylindrical surface of the central protruding portion of the tub
Description
- This application claims the benefit of European Application Serial No. 15158899.3, filed Mar. 12, 2015, the entirety of which is incorporated herein by reference.
- The present invention relates to a washing machine with a direct drive motor system comprising a tub, a drum rotatably mounted inside the tub, and a shaft connected to the drum for transmitting a driving torque of said direct drive motor system, this latter comprising a rotor assembly fastened to the shaft and a stator fastened to the tub. Such known solution has the problem of a high precision alignment between the stator and the rotor, such alignment being required for guaranteeing proper air gap between rotor magnets and stator coils. Since the rotor and the stator are fastened to different components and to different areas of the rear wall of the tub, proper centering is of paramount importance for a correct working of the direct drive motor system.
- Existing solutions for solving the above centering problem comprise a stator centering (before final fastening) on plastic pins provided “ad hoc” on the tub, a stator centering on a cylindrical reworked metal hub surface, or a stator centering on metal pins provided on the metal hub. All the above solutions require special features for guaranteeing a proper centering, which increase the overall cost of the appliance and the complexity of the assembly thereof.
- EP 2626459 discloses a washing machine having a direct drive motor where the stator comprises fixing pins inserted into the rear wall of the tub. The use of pins and holes make the overall construction of the washing machine more complex.
- EP 1580311 discloses a direct drive motor where the stator is centered by means of a cylindrical or conical protuberance which enters the bearing hole which is precisely machined in order to seat ball bearings. This known solution requires to reduce the axial distance of the ball bearings, with a direct impact on the rigidity of the drum shaft support, or to increase the axial dimension of the central portion of the bearing spider. Moreover the solution disclosed by EP 1580311 is not for washing machine having a plastic tub, since it is clearly fit for washing machines having a metal tub.
- DE 10060940 discloses a washing machine which, similarly to EP 1580311, uses a metal bearing spider which cooperates with an axial protrusion of the stator during reciprocal engagement. Metal surface of the bearing spider has to be precisely machined in order to properly center the stator.
- In one aspect of the invention, a washing machine with a direct drive motor system includes a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving torque of a direct drive motor. The motor includes a rotor assembly fastened to the shaft and a stator assembly fastened to the tub. The plastic tub has a central protruding portion where a central opening of the stator assembly is centered before its final fastening to the tub. The central opening of the stator assembly presents a plurality of centering surfaces configured to cooperate with an outside cylindrical surface of the central protruding portion of the tub.
- In another aspect of the invention, a method for producing a washing machine with a direct drive motor system is provided where the washing machine includes a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving force of a direct drive motor, and the motor has a rotor assembly fastened to the shaft and a stator assembly fastened to the tub. The method includes co-injecting the plastic tub on a metal reinforcing element which acts also as a central hub so that a central protruding plastic portion is created as a plastic layer on one end of the hub. The stator assembly axially slides on the plastic layer in order to center the stator assembly. A plurality of centering surfaces provided on the central opening of the stator assembly cooperates with an outside cylindrical surface of the central protruding portion of the tub during the axially sliding. The centering of the stator on the tub is made by using only specific centering surfaces of the stator provided on the edge of the central opening used for its assembly to the protruding portion of the tub.
-
FIG. 1 is a cross longitudinal section of the rear wall of a tub of a washing machine according to the invention, in which the direct drive motor system is installed. -
FIG. 2 is an enlarged detail ofFIG. 1 . -
FIG. 3 is a detail of a front view of the rear wall of the tub, where the rotor has been removed. - With reference to the drawings, a direct drive washing machine comprises a plastic tub 10 whose rear wall 10 a presents a reinforcing star-shaped metal element 12 which forms also a central hub 12 a for
mounting ball bearings 14.Such bearings 14 are used supporting ashaft 16 supporting adrum 18. - According to the invention, the rear wall 10 a of the plastic tub 10 presents an axial
rear protrusion 20 having a first portion 20 a slightly tapered and a second portion 20 b which is cylindrical and whose diameter corresponds exactly to the diameter of a circumference defined by three centeringcurved surfaces 22 formed on an edge 22 a of a central hole of astator 24. - On one end 16 a of the
shaft 16 opposite the drum 18 a cup-shaped rotor 26 is mounted. - In order to mount the
stator 24 in a correct angular position on the tub 10, the rear wall 10 a of the tub presents, on its axial protrusion 20 a radial extension 28 (FIG. 3 ) which corresponds to aradial seat 30 of thestator 24. - When the direct drive motor is assembled to the tub 10, first step is to insert the
stator 24 on theaxial protrusion 20 of the tub, so thatcentering surfaces 22 slide first on the tapered portion 20 a for a pre-centering operation and then it slides on a cylindricalsmooth surface 21 of a portion 20 b for a final centering operation, such movement ending when thestator 24 abuts the rear wall 10 a of the tub 10. Then thestator 24, perfectly centered on the tub 10, is fixed in a known way by means ofscrews 32. - Next and final step is to install the
rotor 26 on the end 16 a of theshaft 16. - In order to allow a precise dimension of the
axial protrusion 20 of the tub 10, particularly of the plastic portion A which covers the metal hub 12 a, it is important that, whatever polymeric material is used in the injection molding process, the injection point or points is placed very close to A in order to get rid of any shrinkage effect or any surface defects. - By injecting plastic material of the tub in a central zone thereof, particularly in a central zone of the rear wall of the tub, such central zone can maintain very strict dimensional tolerances which allows a precise centering of the stator, without any need of auxiliary centering pins or reworking of coupling metal surfaces. Such solution is therefore very simple and allow to obtain a high precision in the centering process while, at the same time, maintain the use of a plastic tub with related advantages in terms of cost and productivity. The applicant believes that such high precision is mainly due to the molding condition of the central zone of the tub, with high pressure and temperature which overcome problems of defects and shrinkage. Such degree of precision of the central part of the molded drum is identical or similar to the precision of machined metal surfaces. Moreover such precision is maintained even if the tub is stored in environment where the metal machined surface could be affected by corrosion or the like.
- To the extent not already described, the different features and structures of the various embodiments can be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments can be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. All combinations or permutations of features described herein are covered by this disclosure.
- While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.
Claims (9)
1. A washing machine with a direct drive motor system comprises:
a plastic tub,
a drum rotatably mounted inside the tub, and
a shaft connected to the drum for transmitting a driving torque of a direct drive motor, the motor comprising a rotor assembly fastened to the shaft and a stator assembly fastened to the tub,
wherein that the plastic tub has a central protruding portion upon which a central opening of the stator assembly is centered before it is fastened to the tub, and
wherein the central opening of the stator assembly presents a plurality of centering surfaces configured to cooperate with an outside cylindrical surface of the central protruding portion of the tub.
2. A washing machine according to claim 1 , wherein the central protruding portion of the tub has a tapered part for pre-centering the stator assembly and a cylindrical portion for centering the stator assembly.
3. A washing machine according to claim 2 , wherein at least the central protruding portion of the tub is formed by an outer plastic shell co-injected onto a metal hub where bearings for the shaft are mounted.
4. A washing machine according to claim 3 , wherein the bearings are ball bearings mounted in the metal hub.
5. A washing machine according to claim 1 , wherein at least the central protruding portion of the tub is formed by an outer plastic shell co-injected onto a metal hub where bearings for the shaft are mounted.
6. A washing machine according to claim 1 , wherein the stator assembly is fixed to the tub by means of screws parallel to the shaft.
7. A washing machine according to claim 6 , wherein the screws are fastened to the metal hub.
8. A washing machine according to claim 1 , wherein the central protruding portion has at least one radial extension configured to cooperate with a corresponding seat of the stator assembly for assuring a determined angular position of the stator assembly with reference to the tub.
9. A method for producing a washing machine with a direct drive motor system comprising a plastic tub, a drum rotatably mounted inside the tub and a shaft connected to the drum for transmitting a driving force of a direct drive motor, the motor comprising a rotor assembly fastened to the shaft and a stator assembly fastened to the tub, the method comprising:
co-injecting the plastic tub on a metal reinforcing element which acts also as central hub so that a central protruding plastic portion is created as a plastic layer on one end of the hub, and
axially sliding the stator assembly on the plastic layer in order to center the stator assembly, a plurality of centering surfaces provided on the central opening of the stator assembly cooperating with an outside cylindrical surface of the central protruding portion of the tub during the axially sliding.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP15158899.3 | 2015-03-12 | ||
EP15158899.3A EP3067457B1 (en) | 2015-03-12 | 2015-03-12 | Washing machine with direct drive motor and method for its manufacturing |
Publications (1)
Publication Number | Publication Date |
---|---|
US20160265151A1 true US20160265151A1 (en) | 2016-09-15 |
Family
ID=52669521
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/065,454 Abandoned US20160265151A1 (en) | 2015-03-12 | 2016-03-09 | Washing machine with direct drive motor and method for its manufacture |
Country Status (2)
Country | Link |
---|---|
US (1) | US20160265151A1 (en) |
EP (1) | EP3067457B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108797005A (en) * | 2017-05-02 | 2018-11-13 | 青岛海尔滚筒洗衣机有限公司 | A kind of roller washing machine using direct driving motor |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10487435B2 (en) | 2017-03-23 | 2019-11-26 | Midea Group Co., Ltd. | Tub for a laundry washing machine |
US10975513B2 (en) | 2017-03-23 | 2021-04-13 | Midea Group Co., Ltd. | Tub with bearing housing insert for a laundry washing machine |
EP3656909B1 (en) * | 2018-11-22 | 2023-07-19 | HAIER Germany GmbH | Washing machine |
CN110144703B (en) * | 2019-06-27 | 2021-02-12 | 朱幕松 | Low noise drum type washing machine |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10060940A1 (en) | 2000-12-07 | 2002-06-13 | Bsh Bosch Siemens Hausgeraete | Motor has protrusion on stator bearer part to form guiding engagement with aperture near bearer star for assembly with approximate positioning with respect to center axis |
DE102004049549A1 (en) | 2004-03-24 | 2005-10-13 | Diehl Ako Stiftung & Co. Kg | Motor as direct drive and method of mounting the motor |
KR100651849B1 (en) * | 2005-02-01 | 2006-12-01 | 엘지전자 주식회사 | Washing Machine |
JP4044602B1 (en) * | 2007-02-14 | 2008-02-06 | 松下電器産業株式会社 | Method for assembling washing machine motor and washing machine motor |
KR20130091019A (en) | 2012-02-07 | 2013-08-16 | 삼성전자주식회사 | Motor and washing machine having the same |
-
2015
- 2015-03-12 EP EP15158899.3A patent/EP3067457B1/en not_active Not-in-force
-
2016
- 2016-03-09 US US15/065,454 patent/US20160265151A1/en not_active Abandoned
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108797005A (en) * | 2017-05-02 | 2018-11-13 | 青岛海尔滚筒洗衣机有限公司 | A kind of roller washing machine using direct driving motor |
Also Published As
Publication number | Publication date |
---|---|
EP3067457A1 (en) | 2016-09-14 |
EP3067457B1 (en) | 2018-05-30 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: WHIRLPOOL CORPORATION, MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HELDAK, DUSAN;PETRACEK, VACLAV;OLEJAR, VLADIMIR;AND OTHERS;SIGNING DATES FROM 20160211 TO 20160215;REEL/FRAME:037948/0811 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |