Washing machine

Abstract

A washing machine includes a rotary tub having a diameter progressively increasing from a first end side thereof to a second end side thereof located opposite the first end side, dehydration holes arranged at the second end side of the rotary tub, and a dehydration hole switching unit to open and close the dehydration holes. The dehydration holes are opened depending on increase of a rate of rotation of the rotary tub.

1 . A washing machine comprising:
 a rotary tub having a diameter progressively increasing from a first end side thereof to a second end side thereof located opposite the first end side;   at least one dehydration hole arranged at the second end side of the rotary tub; and   a dehydration hole switching unit to open and close the at least one dehydration hole.   
     
     
         2 . The washing machine according to  claim 1 , wherein the dehydration hole switching unit is selectively opened and closed depending on a rate of rotation of the rotary tub. 
     
     
         3 . The washing machine according to  claim 2 , wherein:
 the at least one dehydration hole comprises a plurality of dehydration holes disposed at the rotary tub, to be spaced apart from one another in a circumferential direction; and   the dehydration hole switching unit comprises a plurality of dehydration valves movably installed to open and close the plural dehydration holes depending on movement thereof, respectively, and dehydration valve elastic members to elastically support the dehydration valves.   
     
     
         4 . The washing machine according to  claim 3 , wherein:
 the dehydration hole switching unit further comprises a plurality of switching guides formed in an arc shape, each of which connecting two or more of the plural dehydration valves, and movement guides installed so as to allow opposite ends of each switching guide to be movable in a radial direction; and   the dehydration valve elastic members are respectively disposed at the movement guides, to elastically support the dehydration valves through each switching guide.   
     
     
         5 . The washing machine according to  claim 1 , wherein:
 the rotary tub comprises a drainage hole for drainage; and   the rotary tub further comprises a drainage hole switching unit disposed at the drainage hole, to open and close the drainage hole.   
     
     
         6 . The washing machine according to  claim 5 , wherein the drainage hole switching unit comprises a drainage valve movably installed to open and close the drainage hole depending on a position thereof, and a drainage valve drive unit to move the drainage valve. 
     
     
         7 . The washing machine according to  claim 6 , wherein:
 the drainage valve drive unit comprises a solenoid; and   the drainage valve comprises a valve portion to open and close the drainage hole, a plunger portion made of a magnetic substance, and a guide portion to connect the valve portion to the plunger portion and to guide movement of the drainage valve.   
     
     
         8 . The washing machine according to  claim 1 , further comprising:
 a rotational shaft mounted, at one end thereof, to a central portion of a rear surface of the rotary tub, a bearing housing provided with a shaft mounting hole through which the rotational shaft is mounted, and bearings mounted at the shaft mounting hole so as to rotatably support the rotational shaft, wherein:   the bearing housing comprises a first feed passage to guide water used for washing; and   the rotary tub comprises a feed guide portion extending rearward from a periphery of the rotational shaft while being provided therein with a second feed passage connected to the first feed passage so as to guide water supplied from the first feed passage into the rotary tub.   
     
     
         9 . The washing machine according to  claim 1 , further comprising a gutter disposed at an outer side of the rotary tub so as to guide drainage of water discharged from the rotary tub. 
     
     
         10 . A washing machine comprising:
 a main body;   a rotary tub rotatably mounted within the main body; and   a gutter disposed at an outer side of the rotary tub so as to guide drainage of water discharged from the rotary tub,   wherein the rotary tub comprises at least one dehydration hole which is selectively opened only during dehydration.   
     
     
         11 . The washing machine according to  claim 10 , further comprising a dehydration hole switching unit which selectively opens the at least one dehydration hole only during dehydration. 
     
     
         12 . The washing machine according to  claim 11 , wherein the dehydration hole switching unit selectively opens and closes the dehydration hole depending on a rate of rotation of the rotary tub. 
     
     
         13 . The washing machine according to  claim 12 , wherein:
 the at least one dehydration hole comprises a plurality of dehydration holes disposed at the rotary tub, to be spaced apart from one another in a circumferential direction; and   the dehydration hole switching unit comprises a plurality of dehydration valves movably installed to open and close the plural dehydration holes depending on movement thereof, respectively, and dehydration valve elastic members to elastically support the dehydration valves.   
     
     
         14 . The washing machine according to  claim 13 , wherein:
 the dehydration hole switching unit further comprises a plurality of switching guides formed in an arc shape, each of which connecting two or more of the plural dehydration valves, and movement guides installed so as to allow opposite ends of each switching guide to be movable in a radial direction; and   the dehydration valve elastic members are respectively disposed at the movement guides, to elastically support the dehydration valves through each switching guide.   
     
     
         15 . The washing machine according to  claim 6 , wherein the drainage hole switching unit further comprises a drainage valve elastic member to elastically support the drainage valve. 
     
     
         16 . The washing machine according to  claim 10 , wherein the rotary tub comprises a drainage hole for drainage and a drainage hole switching unit disposed at the drainage hole to open and close the drainage hole. 
     
     
         17 . The washing machine according to  claim 16 , wherein the drainage hole switching unit comprises a drainage valve movably installed to open and close the drainage hole depending on a position thereof, and a drainage valve drive unit to move the drainage valve. 
     
     
         18 . The washing machine according to  claim 17 , wherein:
 the drainage valve drive unit comprises a solenoid; and   the drainage valve comprises a valve portion to open and close the drainage hole, a plunger portion made of a magnetic substance, and a guide portion to connect the valve portion to the plunger portion and to guide movement of the drainage valve.   
     
     
         19 . The washing machine according to  claim 17 , wherein the drainage hole switching unit further comprises a drainage valve elastic member to elastically support the drainage valve.