Washing machine with buoyancy clutch and controlling method thereof

Patent metadata

Field	Value
Publication number	US-9845560-B2
Application number	US-201113997111-A
Country	US
Kind code	B2
Filing date	Dec 26, 2011
Priority date	Dec 27, 2010
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

The washing machine includes an outer tub, an inner tub rotatably provided in the outer tub, a pulsator rotatably provided in the inner tub, a power transmission shaft rotating the pulsator, a buoyancy clutch that moves up and down by buoyancy created by wash water and transfers, when the buoyancy clutch is in a lower position, rotational force from the power transmission shaft to the inner tub to allow the pulsator and the inner tub to rotate integrally with each other, a circulation passage that is provided on an outer portion of the outer tub to allow the wash water drained out of the outer tub to be returned into the outer tub, a pump provided on the circulation passage and a drain guide unit that directs the wash water under the buoyancy clutch to a drain hole of the outer tub so that the buoyancy clutch moves downward.

First claim

The invention claimed is:

1. A washing machine, comprising:
an outer tub holding wash water;
an inner tub rotatably provided in the outer tub and receiving laundry;
a pulsator rotatably provided in the inner tub;
a pair of coaxial driving shafts comprising a first driving shaft coupled to the pulsator and a second driving shaft for rotating with the inner tub;
a buoyancy clutch disposed between the pulsator and the outer tub, the buoyancy clutch configured to rotate with the first driving shaft, and move up and down along the first driving shaft in accordance with buoyancy created by the wash water,
wherein the buoyancy clutch is disengaged with the second driving shaft in an upper position, and is engaged with the second driving shaft in a lower position to allow the pulsator to rotate with the inner tub;
a circulation passage allowing the wash water drained out of the outer tub to be returned into the outer tub;
a pump provided on the circulation passage;
a hub supporting the inner tub, the hub disposed between the buoyancy clutch and the outer tub,
wherein the hub is provided with an upwardly extending cylindrical barrier for storing the wash water below the buoyancy clutch and a plurality of through holes are formed at the hub in a region surrounded by the barrier; and
a passage guide that is disposed between the hub and the outer tub to direct the wash water drained through the through holes formed on the hub to a drain hole of the outer tub, the drain hole being connected to the circulation passage,
wherein the cylindrical barrier is disposed below the buoyancy clutch within an area surrounded by the buoyancy clutch when the buoyancy clutch is located at the lower position.

2. The washing machine of claim 1 , wherein the passage guide is provided with an opening through which the pair of driving shafts passes and the inner circumference of the opening is spaced apart from the pair of driving shafts so as not to interfere with the pair of driving shafts.

3. The washing machine of claim 2 , wherein the passage guide has a passage width that is gradually reduced from the opening to the drain hole formed on the outer tub.

4. The washing machine of claim 1 , further comprising:
a rib formed along a circumference of the passage guide.

5. The washing machine of claim 1 , further comprising:
a motor rotating the first driving shaft; and
a controller that controls the pump such that the pump operates to drain the wash water from the outer tub for lowering the buoyancy clutch and controls the motor such that the motor continuously rotates the first driving shaft in one direction during the operation of the pump.

6. The washing machine of claim 5 , wherein the controller controls rotation of the inner tub such that the wash water flows along a space between the inner and outer tub to a level higher than an upper end of the inner tub.

7. The washing machine of claim 5 , further comprising:
a driving detecting unit for detecting a driving state of the motor, wherein the controller changes a control of the motor such that the motor alternately rotates the first driving shaft in both directions based on the driving state of the motor which is detected while the motor is controlled to be continuously rotated in one direction.

8. The washing machine of claim 1 , wherein the first and second driving shafts are coaxially aligned and have different outer diameters, wherein the buoyancy clutch comprises a floater that moves up and down along the first driving shaft and a second driving shaft engaging portion that engages with the second driving shaft when the floater is in the lower position.

9. A washing machine comprising:
an outer tub holding wash water;
an inner tub rotatably provided in the outer tub and receiving laundry;
a pulsator rotatably provided in the inner tub;
a power transmission shaft rotating the pulsator;
a buoyancy clutch that moves up and down by buoyancy created by the wash water and transfers, when the buoyancy clutch is in a lower position, rotational force from the power transmission shaft to the inner tub to allow the pulsator and the inner tub to rotate with each other;
a circulation passage allowing the wash water drained out of the outer tub to be returned into the outer tub;
a pump provided on the circulation passage;
a drain guide unit that directs the wash water under the buoyancy clutch to a drain hole of the outer tub so that the buoyancy clutch moves downward; and
a hub that supports the inner tub and is configured to be rotated with the inner tub, the hub being rotated by the power transmission shaft when the buoyancy clutch is at the lower position,
wherein the hub is provided with an upwardly extending cylindrical barrier for storing the wash water below the buoyancy clutch and the through holes are formed at the hub in a region surrounded by the barrier, and
wherein the cylindrical barrier is disposed below the buoyancy clutch within an area surrounded by the buoyancy clutch when the buoyancy clutch is located at the lower position.

10. The washing machine of claim 9 , wherein the drain guide unit further comprises:
a passage guide that is disposed between the hub and the outer tub to direct the wash water drained through the through holes formed on the hub to the drain hole of the outer tub, the drain hole being connected to the circulation passage.

11. The washing machine of claim 10 , wherein the passage guide is provided with an opening and has a passage width that is gradually reduced from the opening to the drain hole formed on the outer tub.

12. The washing machine of claim 10 , further comprising a rib formed along a circumference of the passage guide.

13. The washing machine of claim 10 , wherein the passage guide has a first end on which an opening through which the power transmission shaft passes is formed and a second end on which a drain pipe connecting portion connected to a drain pipe formed on the outer tub is formed.

Assignees

• Chang Jae Won
• Lee Kyu Bum
• Kim Young Jong
• Chae Ae Kyung
• Lg Electronics Inc

Inventors

• Chang Jae Won
• Lee Kyu Bum
• Kim Young Jong
• Chae Ae Kyung

Classifications

• D06F23/04 Primary

  and rotating or oscillating about a vertical axis · CPC title

• D06F37/12

  adapted for rotation or oscillation about a vertical axis · CPC title

• D06F37/40 Primary

  for driving the receptacle and an agitator or impeller, e.g. alternatively {(D06F37/304, D06F37/308 take precedence)} · CPC title

• D06F39/085

  Arrangements or adaptations of pumps · CPC title

• D06F2204/06

  Textiles & Paper · mapped topic