Linear compressor

Abstract

Disclosed herein is a linear compressor. The linear compressor comprises a cylinder provided at one side thereof with an outlet part, and a piston reciprocated in the cylinder by means of a liner motor for compressing a fluid. The piston has a fluid flow channel formed therethrough. The fluid flow channel communicates with the interior of the cylinder. To the rear part of the piston is fixedly attached a first muffler so that the first muffler is linearly moved along with the piston. The first muffler has a fluid flow channel formed therein. The fluid flow channel of the first muffler communicates with the fluid flow channel of the piston. The first muffler also has a noise-reducing space defined therein. In the compressor is fixedly mounted a second muffler such that the inner volume of the second muffler is variable as the first muffler is linearly moved. The second muffler has a fluid flow channel formed therein. The fluid flow channel of the second muffler communicates with the fluid flow channel of the first muffler. The second muffler also has a noise-reducing space defined therein. According to the present invention, introduction efficiency of the linear compressor is improved, and noise generated at various bands is effectively reduced.

What is claimed is:  
     
         1 . A linear compressor comprising: 
 a cylinder provided at one side thereof with an outlet part;    a piston reciprocated in the cylinder by means of a liner motor for compressing a fluid, the piston having a fluid flow channel formed therethrough, the fluid flow channel communicating with the interior of the cylinder;    a first muffler fixedly attached to the rear part of the piston so that the first muffler is linearly moved along with the piston, the first muffler having a fluid flow channel formed therein, the fluid flow channel of the first muffler communicating with the fluid flow channel of the piston, the first muffler also having a noise-reducing space defined therein; and    a second muffler fixedly mounted in the compressor such that the inner volume of the second muffler is variable as the first muffler is linearly moved, the second muffler having a fluid flow channel formed therein, the fluid flow channel of the second muffler communicating with the fluid flow channel of the first muffler, the second muffler also having a noise-reducing space defined therein.    
     
     
         2 . The compressor as set forth in  claim 1 , wherein the first muffler is constructed so that the rear part of the first muffler is reciprocated while being inserted in the second muffler.  
     
     
         3 . The compressor as set forth in  claim 2 , wherein the gap distance between the outer circumferential surface of the first muffler and the inner circumferential surface of the second muffler is 0.1 to 1.0 mm.  
     
     
         4 . The compressor as set forth in  claim 1 , wherein the first muffler is formed in the shape of a cylinder having fluid flow holes formed through the front and rear parts thereof, respectively, so that the fluid passes through the fluid flow holes.  
     
     
         5 . The compressor as set forth in  claim 1 , wherein the second muffler is formed in the shape of a cylinder, the cylinder being opened at the front part thereof so that the first muffler is inserted into the second muffler, the cylinder having an inlet hole formed therethrough so that the fluid is introduced through the inlet hole.  
     
     
         6 . The compressor as set forth in  claim 1 , wherein the first muffler is provided with a Helmholtz resonator.  
     
     
         7 . The compressor as set forth in  claim 6 , wherein the Helmholtz resonator has a space formed at the inner circumference of the first muffler in the circumferential direction.  
     
     
         8 . The compressor as set forth in  claim 1 , wherein at least one of the first muffler and the second muffler has a collection space formed internally at the rear part thereof.  
     
     
         9 . The compressor as set forth in  claim 8 , wherein the collection space is formed in the vicinity of an inlet pipe where the hole of the first muffler or the second muffler is extended toward the interior of the muffler.  
     
     
         10 . The compressor as set forth in  claim 9 , wherein the inlet pipe is gradually expanded toward the rear part thereof.  
     
     
         11 . The compressor as set forth in  claim 1 , further comprising a back cover fixed to the rear part of the linear motor, the back cover having an opening formed at the center part thereof, wherein the second muffler is fixedly fitted in the opening of the back cover.  
     
     
         12 . The compressor as set forth in  claim 1 , wherein at least one of the first and second mufflers is made of a non-magnetic material.  
     
     
         13 . A linear compressor comprising: 
 a cylinder provided with an outlet valve;    a piston disposed such that the piston is moved forward/backward in the cylinder, the piston having a fluid flow channel formed therethrough so that a fluid is introduced into the interior of the cylinder through the fluid flow channel;    a linear motor mounted in the compressor for reciprocating the piston;    a back cover fixed to the linear motor such that the back cover surrounds the rear part of the piston, the back cover having an opening formed at the center part thereof;    a first muffler fixedly attached to the rear part of the piston so that the first muffler is reciprocated along with the piston, the first muffler having an inlet hole formed therein so that a fluid is introduced into the first muffler through the inlet hole of the first muffler, the inlet hole of the first muffler communicating with the fluid flow channel of the piston; and    a second muffler fixedly mounted to the back cover such that the inner volume of the second muffler is variable as the first muffler is reciprocated along with the piston, the second muffler having an inlet hole formed therein, the inlet hole of the second muffler communicating with the outside of the back cover so that the fluid existing outside the back cover is introduced into the second muffler through the inlet hole of the second muffler.    
     
     
         14 . The compressor as set forth in  claim 13 , wherein at least one of the first and second mufflers is made of a non-magnetic material.  
     
     
         15 . The compressor as set forth in  claim 13 , wherein the first muffler is constructed so that the rear part of the first muffler is linearly moved while being inserted in the second muffler.  
     
     
         16 . The compressor as set forth in  claim 15 , wherein the gap distance between the first muffler and the second muffler is 0.1 to 1.0 mm.  
     
     
         17 . The compressor as set forth in  claim 13 , wherein the first muffler is provided with a Helmholtz resonator.  
     
     
         18 . The compressor as set forth in  claim 13 , wherein at least one of the first muffler and the second muffler has a collection space formed internally at the rear part thereof.  
     
     
         19 . The compressor as set forth in  claim 18 , wherein the collection space is formed in the vicinity of an inlet pipe where the hole of the first muffler or the second muffler is extended toward the interior of the muffler.  
     
     
         20 . The compressor as set forth in  claim 19 , wherein the inlet pipe is gradually expanded toward the rear part thereof.