Washing machine

Abstract

A washing machine including a tub to retain wash water, a spin basket rotatably installed in the tub, a pulsator rotatably installed in the spin basket, a drive unit to generate rotary power and transmit the rotary power to the pulsator, and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy. The float clutch includes guide protrusions provided at an upper surface thereof to allow the float clutch to be elevatably installed at a lower portion of the pulsator, and the pulsator includes guide grooved provided at a lower surface thereof, the guide protrusions being elevatably installed in the guide grooves. Since the float clutch receives rotary power at a position spaced apart from the shaft installation portion of the pulsator, the rotary power is prevented from being concentrated on the shaft installation portion.

What is claimed is: 
     
         1 . A washing machine comprising:
 a housing forming an external appearance of the washing machine;   a tub disposed inside the housing to retain wash water;   a spin basket rotatably installed in the tub;   a pulsator rotatably installed in the spin basket;   a drive unit to generate rotary power and transmit the rotary power to the pulsator; and   a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy,   wherein the float clutch includes at least one guide protrusion provided at an upper surface thereof to allow the float clutch to be elevatably installed at a lower portion of the pulsator, and   the pulsator includes at least one guide groove provided at a lower surface thereof, the guide protrusion being elevatably installed in the guide groove.   
     
     
         2 . The washing machine according to  claim 1 , wherein the at least one guide protrusion includes a plurality of guide protrusions extending in radial direction of the float clutch and arranged spaced apart from each other in a circumferential direction of the float clutch, and
 the at least one guide groove includes a plurality of guide grooves extending from the pulsator outward in a radial direction of the pulsator and arranged spaced apart from each other in a circumferential direction of the pulsator.   
     
     
         3 . The washing machine according to  claim 2 , wherein the pulsator is provided, on an upper surface thereof, with a plurality of blades extending outward in a radial direction and arranged spaced apart from each other in a circumferential direction,
 the guide grooves are formed at a lower side of the blades in a shape corresponding to a shape of the blades, and   the guide protrusions are formed in a shape corresponding to the shape of the guide grooves.   
     
     
         4 . The washing machine according to  claim 1 , wherein the drive unit includes a transmission shaft having an upper end coupled to the pulsator to transmit the rotary power to the pulsator,
 the pulsator includes a shaft installation portion extending from a center of a lower surface of the pulsator downward, the transmission shaft being installed at the shaft installation portion, and   the float clutch includes a guide hole provided at a center thereof to allow the float clutch to be elevatably installed at the shaft installation portion.   
     
     
         5 . The washing machine according to  claim 4 , wherein the shaft installation portion includes a first uneven part provided on an outer circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the shaft installation portion, and
 the guide hole includes a second uneven part provided on an inner circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the guide hole such that the concave portions and convex portions of the second uneven part respectively match the convex portions and concave portions of the first uneven part.   
     
     
         6 . The washing machine according to  claim 4 , wherein the spin basket includes at least one coupling protrusion adapted to be selectively coupled to the float clutch depending on a position of the float clutch, and
 the float clutch includes at least one coupling groove formed on a lower surface thereof at a position corresponding to a position of the coupling protrusion and adapted to be selectively coupled to the coupling protrusion depending on the position of the float clutch.   
     
     
         7 . The washing machine according to  claim 6 , wherein, the at least one coupling protrusion includes a plurality of coupling protrusions arranged spaced apart from each other in a circumferential direction, and
 the at least one coupling groove includes a plurality of coupling grooves arranged spaced apart from each other in a circumferential direction.   
     
     
         8 . The washing machine according to  claim 7 , wherein the spin basket includes a drive flange fixed to a lower end thereof to receive the rotary power from the float clutch,
 the drive flange includes a hub provided with a through hole allowing the transmission shaft to be installed therethrough, and a plurality of flange portions extending from the hub outward in a radial direction and arranged spaced apart from each other in a circumferential direction, and   the coupling protrusions are arranged at the hub in a circumferential direction.   
     
     
         9 . A washing machine comprising:
 a housing forming an external appearance of the washing machine;   a tub disposed inside the housing to retain wash water;   a spin basket rotatably installed in the tub;   a pulsator rotatably installed in the spin basket;   a drive unit to generate rotary power and transmit the rotary power to the pulsator; and   a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy,   wherein the spin basket includes a drive flange installed at a lower end thereof to receive power from the float clutch,   the drive flange includes at least one coupling protrusion integrally protruding upward from the drive flange to be coupled to the float clutch when the float clutch is lowered, and   the float clutch includes at least one coupling groove provided on a lower surface thereof to be coupled to the coupling protrusion.   
     
     
         10 . The washing machine according to  claim 9 , wherein the at least one coupling protrusion includes a plurality of coupling protrusions arranged at the drive flange spaced apart from each other in a circumferential direction, and
 the at least one coupling groove includes a plurality of coupling grooves arranged at the float clutch spaced apart from each other in a circumferential direction.   
     
     
         11 . The washing machine according to  claim 10 , wherein the drive flange includes a hub having the coupling protrusions, and a flange extending from the hub outward in a radial direction to be fixed to a lower surface of the spin basket. 
     
     
         12 . The washing machine according to  claim 9 , wherein the float clutch is provided therein with an empty space filled with air, thereby achieving buoyancy through the empty space. 
     
     
         13 . The washing machine according to  claim 9 , wherein the float clutch is constructed of injection molded thermoplastic or thermosetting polymer. 
     
     
         14 . The washing machine according to  claim 9 , wherein the float clutch is constructed of a material buoyant in water.