Refrigerant compressor

Abstract

Hermetically encapsulated refrigerant compressor ( 1 ), comprising a cylinder housing ( 3 ), which is used as the basis for manufacturing various refrigerant compressor construction series each having different working volumes and a piston ( 6 ) guided in a piston bore ( 8 ) of the cylinder housing ( 3 ) along a defined piston run surface ( 9 ). According to the invention, it is provided that a free run section ( 10 ) is situated in the piston bore ( 8 ) as a function of the particular working volume to be implemented inside the cylinder housing ( 3 ), which working volume is fixable by a variation of the position of the piston ( 6 ) or the piston run surface ( 9 ) in the piston bore ( 8 ), so that the piston run surface ( 9 ) is reduced to a minimal guide length measured in the direction of the cylinder axis ( 12 ), at which the piston ( 6 ) is only lowered in its bottom dead center position far enough into the area of the piston bore ( 8 ) corresponding to the piston run surface ( 9 ) so that the piston ( 6 ) is just prevented from falling out of the piston bore ( 8 ) and a sealing action of the piston ( 6 ) in relation to the piston run surface ( 9 ) is provided.

1 . A hermetically encapsulated refrigerant compressor ( 1 ), comprising a cylinder housing ( 3 ), which is used as the basis for manufacturing various refrigerant compressor construction series each having different sizes of the working volume, and a piston ( 6 ), which is guided in a piston bore ( 8 ) of the cylinder housing ( 3 ) along a defined piston run surface ( 9 ), for compressing a working medium, which piston is linked using a connecting rod ( 7 ) to a crankshaft ( 5 ) driven by an electric motor ( 13 ), the crankshaft ( 5 ), which is rotatable around a rotational axis ( 11 ), being mounted in a mounting body ( 2 ), and the piston bore ( 8 ) being closed in a first end area ( 8   a ) by a cylinder head ( 15 ) comprising a valve plate ( 16 ), while the piston bore ( 8 ) is open to accommodate the piston ( 6 ) in a second end area ( 8   b ) facing toward the crankshaft ( 5 ), the piston bore ( 8 ) having a free run section ( 10 ) adjoining the piston run surface ( 9 ) and situated in the second end area ( 8   b ) of the piston bore ( 8 ) facing toward the crankshaft ( 5 ), whose clear open width ( 10 ′) is greater than the diameter ( 9 ′) of the piston run surface ( 9 ), in order to prevent a contact between piston ( 6 ) and cylinder housing ( 3 ) in this section during the operating positions of the piston ( 6 ), wherein the free run section ( 10 ) is situated, as a function of the particular working volume to be implemented, within the cylinder housing ( 3 ), which working volume is fixable by a variation of the position of the piston ( 6 ) or the piston run surface ( 9 ) in the piston bore ( 8 ), so that the piston run surface ( 9 ) is reduced to a minimal guide length measured in the direction of the cylinder axis ( 12 ), in the case of which the piston  6  is only lowered in its bottom dead center position into the area of the piston bore  8  corresponding to the piston run surface ( 9 ), so that the piston ( 6 ) is just prevented from falling out of the piston bore ( 8 ) and a sealing action of the piston ( 6 ) in relation to the piston run surface ( 9 ) is provided. 
     
     
         2 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the variation of the position of the piston ( 6 ) or the piston run surface ( 9 ) in the piston bore ( 8 ) is performed via a use of connecting rods  7  and/or pistons  6  dimensioned in different lengths. 
     
     
         3 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1  wherein the variation of the position of the piston ( 6 ) or the piston run surface ( 9 ) in the piston bore ( 8 ) is performed by a variation of the eccentricity of a crank pin ( 19 ), which links the connecting rod ( 7 ) on the crankshaft ( 3 ), in relation to the rotational axis ( 11 ) of the crankshaft ( 3 ). 
     
     
         4 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the free run section ( 10 ) is implemented as a recess in the cylinder housing ( 3 ) which is rotationally symmetric to the cylinder axis ( 12 ). 
     
     
         5 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the clear cross-sectional width ( 10 ′) of the free run section ( 10 ) is greater by more than 1/100 mm, preferably more than 1/10 mm, than the piston bore diameter ( 8 ′). 
     
     
         6 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the piston run surface ( 9 ) merges into the free run section ( 10 ) via a chamfer ( 38 ) or a radius ( 39 ). 
     
     
         7 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the cylinder housing ( 3 ) has a first installation opening ( 24 ) running essentially perpendicularly to the cylinder axis ( 12 ), the central axis ( 25 ) of this installation opening ( 24 ) being situated offset by a distance amount (y) in the direction of the first end area ( 8   a ) of the piston bore ( 8 ) to a piston bolt axis ( 21 ) of a piston ( 6 ) located in its bottom dead center position. 
     
     
         8 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the free run section ( 10 ) is produced by mechanical machining of the piston bore ( 8 ). 
     
     
         9 . The hermetically encapsulated refrigerant compressor ( 1 ) according to  claim 1 , wherein the mounting body ( 2 ) is implemented integrally with the cylinder housing ( 3 ).