Drum-type washing machine having damper and method

Abstract

A drum-type washing machine having a damper, and method, capable of effectively reducing vibration of a water tub includes a housing, a water tub in the housing, and a damper unit having one end affixed to an outer surface of the water tub and an other end affixed to the housing. The damper unit includes a cylinder having one end affixed to one of the housing and the water tub and a piston having one end affixed to the other one of the housing and the water tub and the other end in the cylinder elastically retractable to reduce the transmitted vibration. A frictional pad is on an inner surface of the cylinder or an outer surface of the piston to come into frictional contact, respectively, with the outer surface of the piston or the inner surface of the cylinder, thereby reducing the vibration of the water tub.

1 . A drum-type washing machine comprising: 
 a housing;    a water tub suspendedly mounted in the housing; and    a damper unit having one end affixed to an outer surface of the water tub and an other end affixed to the housing reducing vibration of the water tub, the damper unit comprising: 
 a cylinder having one end affixed to one of the housing and the water tub and an other end having an opening,  
 a piston having one end affixed to the other one of the housing and the water tub and an other end reciprocably received in the cylinder and retractable, and  
 a frictional pad on an inner surface of the cylinder or an outer surface of the piston coming in frictional contact, respectively, with the outer surface of the piston or the inner surface of the cylinder reducing vibration transmitted from the water tub to the piston.  
   
   
   
       2 . The washing machine according to  claim 1 , wherein the piston comprises: 
 a first rod having one end affixed to one of the housing and the water tub and an other end within the cylinder, and    a second rod in the cylinder and connected to the first rod by an elastic member.    
   
   
       3 . The washing machine according to  claim 2 , wherein the second rod has a groove recessed in an outer surface thereof for the positioning of the frictional pad.  
   
   
       4 . The washing machine according to  claim 2 , wherein the frictional pad is a plurality of frictional pads and comprises: 
 a first frictional pad interposed between the inner surface of the cylinder and an outer surface of the first rod, and    a second frictional pad interposed between the inner surface of the cylinder and an outer surface of the second rod.    
   
   
       5 . The washing machine according to  claim 4 , wherein the first rod has a first groove recessed in the outer surface thereof for the positioning of the first frictional pad, and the second rod has a second groove recessed in the outer surface thereof for the positioning of the second frictional pad.  
   
   
       6 . The washing machine according to  claim 4 , wherein the cylinder has a first groove recessed in the inner surface thereof for the positioning of the first frictional pad, and the second rod has a second groove recessed in the outer surface thereof for the positioning of the second frictional pad.  
   
   
       7 . A drum-type washing machine comprising: 
 a housing;    a water tub mounted in the housing; and    a damper unit having one end affixed to an outer surface of the water tub and the other end affixed to the housing reducing vibration of the water tub, the damper unit comprising: 
 a cylinder having one end affixed to one of the housing and the water tub and the other end having an opening,  
 a first rod having one end affixed to the other one of the housing and the water tub and the other end reciprocably received in the cylinder;  
 a second rod received in the cylinder and connected to the first rod by an elastic member; and  
 a plurality of frictional pads between an inner surface of the cylinder and an outer surface of at least one of the first and second rods and configured to come in frictional contact with an inner surface of the cylinder reducing the vibration transmitted from the water tub to the piston.  
   
   
   
       8 . A washing machine comprising: 
 a housing;    a water tub mounted in the housing; and    a damper having one end affixed to an outer surface of the water tub and an other end affixed to the housing, the damper unit comprising: 
 a cylinder having one end affixed to one of the housing and the water tub,  
 a piston having one end affixed to the other one of the housing and the water tub and an other end within the cylinder, the piston comprising: 
 a first rod having one end affixed to one of the housing and the water tub and the other end within the cylinder, and  
 a second rod in the cylinder and connected to the first rod by an elastic member, and  
 
 a frictional pad on an inner surface of the cylinder or an outer surface of the piston positioned to come in frictional contact with the outer surface of the piston or the inner surface of the cylinder, respectively,  
   
   
   
       9 . The washing machine according to  claim 8 , wherein the second rod has a groove.  
   
   
       10 . The washing machine according to  claim 8 , wherein the frictional pad is a plurality of frictional pads and comprises: 
 a first frictional pad positioned between the inner surface of the cylinder and an outer surface of the first rod, and    a second frictional pad between the inner surface of the cylinder and an outer surface of the second rod.    
   
   
       11 . The washing machine according to  claim 10 , wherein the first rod has a first groove in the outer surface, and the second rod has a second groove in the outer surface thereof.  
   
   
       12 . The washing machine according to  claim 10 , wherein the cylinder has a first groove in the inner surface thereof, and the second rod has a second groove in the outer surface thereof.  
   
   
       13 . A method of reducing vibration in a washing machine, the method comprising: 
 absorbing a first value of vibration by elastic deformation of an elastic member; and    absorbing a second value of vibration by the elastic deformation of the elastic member and by friction between surfaces.    
   
   
       14 . The method of reducing vibration in a washing machine according to  claim 14 , wherein the second value of vibration is greater than the first value of vibration.  
   
   
       15 . A damper comprising: 
 a cylinder having one end affixable to one of a housing and a movable part within the housing;    a piston having one end affixed to the other one of the housing and the movable part and an other end within the cylinder; the piston comprising 
 a first rod having one end affixed to one of the housing and the movable part and the other end within the cylinder, and  
 a second rod in the cylinder and connected to the first rod by an elastic member; and  
   a frictional pad positioned on an inner surface of the cylinder or an outer surface of the piston positioned to come in frictional contact with the outer surface of the piston or the inner surface of the cylinder, respectively.    
   
   
       16 . The damper according to  claim 15 , wherein the second rod has a groove.  
   
   
       17 . The damper according to  claim 15 , wherein the frictional pad is a plurality of frictional pads and comprises: 
 a first frictional pad positioned between the inner surface of the cylinder and an outer surface of the first rod, and    a second frictional pad between the inner surface of the cylinder and an outer surface of the second rod.    
   
   
       18 . The damper according to  claim 15 , wherein the first rod has a first groove in the outer surface thereof, and the second rod has a second groove in the outer surface thereof.  
   
   
       19 . The damper according to  claim 15 , wherein the cylinder has a first groove in the inner surface thereof, and the second rod has a second groove in the outer surface.