Compressor

Abstract

A reciprocating compressor ( 10 ) comprises a casing ( 11 ), inside which two chambers are defined, respectively a first chamber ( 12 ) corresponding to the compression section, which, in turn, comprises at least one piston ( 16 ), a slider-crank mechanism ( 17 ) and an oil box, and a second chamber ( 13 ) for the motor ( 14 ) of the compressor. A transmission shaft ( 18 ) is provided, operatively connected to said motor and to said slider-crank mechanism. Said chambers are separated by means of a supporting portion ( 19 ) of said shaft, said supporting portion having a passage ( 20 ) for said shaft, wherein at least one anti-friction bushing ( 21 ) is provided in said passage for supporting said shaft. An oil supply duct ( 22 ) is provided at least partially inside said shaft, wherein the duct ( 22 ) has at least an end opening ( 23, 25 ) exiting in the space between said shaft and said passage so as to allow the lubrication of said at least one anti-friction bushing and said shaft. A niche ( 24, 26 ) is provided between the end of said passage ( 20 ) facing said second chamber ( 13 ) and said end opening ( 23, 25 ) of said duct. A discharge channel ( 27 ) is operatively connected to said niche and to said oil box, so that the oil lubricating the anti-friction bushing ( 21 ) and coming from the end opening is depressurized and adapted to come back into said oil box, thus eliminating or limiting the amount of oil reaching the second chamber with the motor.

1 . A compressor for cooling systems and/or air conditioning systems and/or heat pumps, of the reciprocating type, the compressor comprising
 a casing, inside which two chambers are defined, respectively a first chamber and a second chamber   a compression section, the first chamber corresponding to the compression section, which compression section comprises at least one compression piston, a corresponding slider-crank mechanism for moving the piston and an oil box;   a motor of the compressor, wherein the second chamber is for the motor of the compressor;   a transmission shaft operatively connected to said motor and to said slider-crank mechanism;   a support portion of said transmission shaft, said chambers being separated by means of the support portion of said transmission shaft, said support portion having a passage for said shaft;   at least one anti-friction bushing supporting said shaft, said at least one anti-friction bushing supporting said transmission shaft;   an oil supply duct provided at least partially inside said transmission shaft, the oil supply duct having an end opening exiting in the space between said shaft and said passage so as to allow lubrication of said at least one anti-friction bushing and said shaft;   a niche provided in a position comprised between the end of said passage facing said second chamber and said end opening of said oil supply duct; and   a discharge channel operatively connected to said niche and to said oil box, so that oil lubricating said at least one anti-friction bushing and coming from said end opening is depressurized and adapted to come back at least partially into said oil box, thus eliminating or limiting an amount of oil achieving said second chamber with the motor.   
     
     
         2 . The compressor of  claim 1 , wherein said niche is provided on a surface of said transmission shaft or on a surface of said at least one anti-friction bushing, facing said shaft; and said niche comprises an annular recess or a niche extending all around an axis of said shaft. 
     
     
         3 . The compressor of  claim 1 , wherein said discharge channel is provided on an inner surface of said passage. 
     
     
         4 . The compressor of  claim 1 , wherein said discharge channel and said niche are directly connected by means of a through hole provided through said at least one anti-friction bushing. 
     
     
         5 . The compressor of  claim 1 , wherein said discharge channel is provided on a surface of said support portion and has three closing sides formed by said support portion and a fourth side closed by said at least one anti-friction bushing. 
     
     
         6 . The compressor of  claim 1 , wherein said at least one end opening of the oil supply duct exits outside said niche operatively connected to said discharge channel; said niche being preferably open on said discharge channel. 
     
     
         7 . The compressor of  claim 1 , further comprising a ring for limiting the oil leakage, provided around said shaft in a position opposite to said at least one end opening of the oil duct and with respect to said niche. 
     
     
         8 . The compressor of  claim 7 , wherein said oil leakage limiting ring is arranged in a seat provided at the end of said passage facing said second chamber. 
     
     
         9 . The compressor of  claim 1 , comprising two said anti-friction bushings arranged in series after each other in said passage. 
     
     
         10 . The compressor of  claim 1 , comprising a further niche where a said end opening exits, provided in the form of annular recess on said shaft, or a further niche extending all around said shaft. 
     
     
         11 . The compressor of  claim 1 , further comprising a further end opening directly exiting on a surface of said shaft into contact with said at least one anti-friction bushing.