Piston cylinder arrangement of an aerostatic linear compressor

Abstract

A piston ( 1 ) and cylinder ( 2 ) assembly that can reduce efficiency losses due to the gas in a linear compressor with aerostatic bearings. The space between the piston ( 1 ) and cylinder ( 2 ) in the piston-cylinder assembly was designed to decrease radial clearance ( 12 ) in the upper portion of the piston ( 1 ) when the piston approaches the headpiece ( 3 ), i.e., when the density of the gas not being used in the refrigeration process is the highest. The piston ( 1 ) and cylinder ( 2 ) assembly must exhibit such a geometric ratio that radial clearance ( 12 ) changes in inverse proportion to the density of the gas in the radial clearance ( 12 ).

1 - 23 . (canceled) 
     
     
         24 . A piston/cylinder assembly, comprising a piston ( 1 ) and a cylinder ( 2 ), the piston ( 1 ) being displaceably positioned inside the cylinder ( 2 ),
 the piston moving between a top dead center (TDC/PMS) and a bottom dead center (BDC/PMI),   between an inner wall of the cylinder ( 2 ) and an outer wall of the piston ( 91 ) there being a perimeter clearance ( 12 ) for aerostatic bearing arrangement ( 1 ),   wherein:
 there is a minimum perimeter clearance ( 12 ) at the top portion of the piston ( 1 ) when the piston ( 1 ) is at its top dead center (TDC/PMS), 
 the clearance ( 12 ) is always smaller at the top portion of the piston ( 1 ) than in any other region of the piston/cylinder assembly. 
   
     
     
         25 . The piston/cylinder assembly according to  claim 24 , wherein the perimeter clearance ( 12 ) is variable from the bottom dead center (BDC/PMI) to the top dead center (TDC/PMS). 
     
     
         26 . The piston/cylinder assembly according to  claim 25 , wherein the closer to the top portion of the piston ( 1 ) top the perimeter clearance ( 12 ) is, the smaller it is. 
     
     
         27 . The piston/cylinder assembly according to  claim 26 , wherein the piston ( 1 ) comprises a variable cross-section. Page  4   
     
     
         28 . The piston/cylinder assembly according to  claim 27 , wherein the cylinder ( 1 ) comprises a variable cross-section. 
     
     
         29 . The piston/cylinder assembly according to  claim 28 , wherein the top portion of the piston ( 1 ) has a dimension larger than a remaining portion of the piston ( 1 ). 
     
     
         30 . The piston/cylinder assembly according to  claim 29 , wherein the top portion of the cylinder ( 2 ) has a dimension smaller than the remaining portion of the cylinder ( 2 ). 
     
     
         31 . The piston/cylinder assembly according to  claim 30 , wherein the piston ( 1 ) is conical. 
     
     
         32 . The piston/cylinder assembly according to  claim 31 , wherein the piston ( 1 ) comprises a circle-segment shape. 
     
     
         33 . The piston/cylinder assembly according to  claim 32 , wherein the cylinder ( 2 ) comprises frustum-type geometry. 
     
     
         34 . The piston/cylinder assembly according to  claim 33 , wherein the cylinder ( 2 ) comprises a circle-segment shape. 
     
     
         35 . A linear compressor comprising a piston/cylinder assembly, said piston/cylinder assembly of said linear compressor comprising:
 a piston ( 1 ) and a cylinder ( 2 ), the piston ( 1 ) being displaceably positioned inside the cylinder ( 2 ),   the piston moving between a top dead center (TDC/PMS) and a bottom dead center (BDC/PMI),   between an inner wall of the cylinder ( 2 ) and an outer wall of the piston ( 91 ) there being a perimeter clearance ( 12 ) for aerostatic bearing arrangement ( 1 ),   wherein:
 there is a minimum perimeter clearance ( 12 ) at the top portion of the piston ( 1 ) when the piston ( 1 ) is at its top dead center (TDC/PMS), 
 the clearance ( 12 ) is always smaller at the top portion of the piston ( 1 ) than in any other region of the piston/cylinder assembly. 
   
     
     
         36 . A piston/cylinder assembly for a linear compressor, said piston/cylinder assembly comprising a piston ( 1 ) and a cylinder ( 2 ), the piston ( 1 ) being displaceably positioned within the cylinder ( 2 ),
 the piston ( 1 ) moving between a high-pressure portion (Pd) and a low-pressure portion (Ps),   the high-pressure portion (Pd) having higher gas density than the low-pressure portion (Ps),   a perimeter clearance ( 12 ) being defined between an inner wall of the cylinder ( 2 ) and an outer wall of the piston ( 1 ) for aerostatic bearing arrangement ( 1 ) with gas,   wherein the dimension of the perimeter clearance ( 12 ) varies in an inversely proportional manner with respect to the gas density in the perimeter clearance ( 12 ).   
     
     
         37 . The piston/cylinder assembly according to  claim 36 , wherein the piston ( 1 ) comprises a variable cross-section. 
     
     
         38 . The piston/cylinder assembly according to  claim 37 , wherein the cylinder ( 1 ) comprises a variable cross-section. 
     
     
         39 . The piston/cylinder assembly according to  claims 38 , wherein the top portion of the piston ( 1 ) comprises a larger dimension than a remaining portion of the piston ( 1 ). 
     
     
         40 . The piston/cylinder assembly according to  claim 39 , wherein the top portion of the cylinder ( 2 ) has a smaller dimension than the remaining portion of the cylinder ( 2 ). 
     
     
         41 . The piston/cylinder assembly according to  claim 40 , wherein the piston ( 1 ) is conical. 
     
     
         42 . The piston/cylinder assembly according to  claim 41 , wherein the piston ( 1 ) comprises a circle-segment shape. 
     
     
         43 . The piston/cylinder assembly according to  claim 42 , wherein the cylinder ( 2 ) is conical. 
     
     
         44 . The piston/cylinder assembly according to  claim 43 , wherein the cylinder ( 2 ) comprises a circle-segment shape. 
     
     
         45 . A linear compressor comprising a piston/cylinder assembly, said piston/cylinder assembly of said linear compressor comprising:
 a piston ( 1 ) and a cylinder ( 2 ), the piston ( 1 ) being displaceably positioned within the cylinder ( 2 ),   the piston ( 1 ) moving between a high-pressure portion (Pd) and a low-pressure portion (Ps),   the high-pressure portion (Pd) having higher gas density than the low-pressure portion (Ps),   a perimeter clearance ( 12 ) being defined between an inner wall of the cylinder ( 2 ) and an outer wall of the piston ( 1 ) for aerostatic bearing arrangement ( 1 ) with gas,   wherein the dimension of the perimeter clearance ( 12 ) varies in an inversely proportional manner with respect to the gas density in the perimeter clearance ( 12 ).   
     
     
         46 . A piston/cylinder assembly, the piston ( 1 ) being displaceably positioned within the cylinder ( 2 ),
 the piston ( 1 ) moving between a top dead center (TDC/PMS) and a bottom dead center (BDC/PMI),   between an inner wall of the cylinder ( 2 ) and an outer wall of the piston ( 1 ) there being a perimeter clearance ( 12 ) for aerostatic bearing arrangement of the piston ( 1 ),   the piston/cylinder assembly comprising a varying cross-section defining a perimeter clearance ( 12 ) which is minimum when the piston ( 1 ) is at its top dead center (TDC/PMS), and   the closer to a head ( 3 ) the piston ( 1 ) is, the smaller the perimeter clearance.