Washing machine with direct drive motor and method for its manufacture

Patent metadata

Field	Value
Publication number	US-2016265151-A1
Application number	US-201615065454-A
Country	US
Kind code	A1
Filing date	Mar 9, 2016
Priority date	Mar 12, 2015
Publication date	Sep 15, 2016
Grant date	—

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

First claim

What is claimed is:

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.

Assignees

• Whirlpool Co

Inventors

• Heldak Dusan
• Petracek Vaclav
• Olejar Vladimir
• Vasko Pavol
• Mihalka Peter
• Iannicelli Crescenzo

Classifications

• D06F37/30 Primary

  Driving arrangements  (control circuits or arrangements D06F34/08) · CPC title

• D06F37/206 Primary

  Mounting of motor · CPC title

• D06F37/262

  made of plastic material, e.g. by injection moulding · CPC title

• D06F37/261

  Tubs made by a specially selected manufacturing process or characterised by their assembly from elements · CPC title

• D06F37/264

  Tubs provided with reinforcing structures, e.g. ribs, inserts, braces · CPC title