Flow restrictor and gas compressor

Abstract

A flow restrictor is adapted for application in a bearing arrangement between a piston and a cylinder of a gas compressor. The compressor includes a protective block that involves the cylinder externally, and also includes at least one inner cavity, which is fluidly fed by a discharge flow resulting from a compression movement exerted by the piston inside the cylinder. The compressor includes a bearing-arrangement clearance that separates the piston and an inner wall of the cylinder. The compressor includes at least one flow restrictor provided with a housing that associates fluidly the inner cavity to the bearing-arrangement clearance. The flow restrictor is associated to the housing by a process of at least partial plastic deformation inside the housing, the flow restrictor being provided with channels for passage of fluid, the plastic deformation being sized for limiting the gas flow through the inner cavity to the bearing-arrangement clearance.

1 . A method of mounting a flow restrictor for an aerostatic bearing application in a gas compressor, said method comprising:
 providing a bushing made of a metallic material comprising at least one of aluminum, tin, copper, bronze, and brass;   wherein the bushing is provided with at least one passage channel for an aerostatic bearing fluid;   plastically deforming the bushing such that the plastic deformation of the bushing associates the bushing to a housing whereby the at least one passage channel of the plastically deformed bushing defines a restrictive path provided with a cross-section sized to limit flow of aerostatic bearing fluid through the at least one passage channel;   wherein the step of plastically deforming the bushing is made by flattening, reducing the length and increasing a diameter of the bushing with a gradual decrease in the cross-sectional area of the at least one passage channel and constriction of the at least one passage channel.   
     
     
         2 . The method of mounting a flow restrictor according to  claim 1 , wherein the deformation is either partial or total. 
     
     
         3 . The method of mounting a flow restrictor according to  claim 1 , wherein the deformation is made either by: (i) a single tool; or (ii) two or more tools counterposing the movement of each other. 
     
     
         4 . The method of mounting a flow restrictor according to  claim 1 , wherein the bushing is made of a porous material. 
     
     
         5 . The method of mounting a flow restrictor according to  claim 1 , wherein the at least one passage channel in the bushing comprises straight or helical grooves formed in an outer surface of the bushing along a length of the bushing. 
     
     
         6 . The method of mounting a flow restrictor according to  claim 1 , wherein the at least one passage channel in the bushing comprises a serration formed in an outer surface of the bushing along a length of the bushing. 
     
     
         7 . The method of mounting a flow restrictor according to  claim 1 , wherein the at least one passage in the bushing comprises an inner thread throughout a length of the bushing such that said inner thread defines a passage for aerostatic bearing fluid to flow through the bushing. 
     
     
         8 . The method of mounting a flow restrictor according to  claim 1 , wherein the at least one passage in the bushing comprises at least one of a slot, a cavity, or a bore throughout a length of the bushing such that said at least one slot, cavity, or bore defines a passage for aerostatic bearing fluid to flow through the bushing. 
     
     
         9 . The method of mounting a flow restrictor according to  claim 1 , wherein the bushing further comprises at least one cavity of cylindrical or conical shape defined therein, wherein said cavity facilitates deformation of the bushing. 
     
     
         10 . A method of mounting a flow restrictor in a cylinder for a gas compressor, said method comprising:
 providing a cylinder for a gas compressor, said cylinder adapted to receive an associated piston, said cylinder comprising a housing bore provided through a wall of the cylinder;   installing a bushing in the housing bore, wherein said bushing is made of a metallic material comprising at least one metal selected from the group of: aluminum, tin, copper, bronze, brass, and wherein said busing comprises a passage channel defined therein for flow of aerostatic bearing fluid through the passage channel;   said step of installing said busing in said housing bore comprising deforming said bushing and the passage channel relative to said housing bore such that said bushing is engaged with the wall of the cylinder and fixedly secured in said housing bore and such that the deformed passage channel defines a restricted flow path through said housing bore for aerostaic bearing fluid.   
     
     
         11 . The method of mounting a flow restrictor according to  claim 10 , wherein the deforming of the bushing is either partial or total. 
     
     
         12 . The method of mounting a flow restrictor according to  claim 10 , wherein the deforming comprising using either: (i) a single tool; or (ii) two or more tools counterposing the movement of each other. 
     
     
         13 . The method of mounting a flow restrictor according to  claim 10 , wherein the bushing is made of a porous material. 
     
     
         14 . The method of mounting a flow restrictor according to  claim 10 , wherein the passage channel in the bushing comprises a straight or helical groove formed in an outer surface of the bushing along a length of the bushing. 
     
     
         15 . The method of mounting a flow restrictor according to  claim 10 , wherein the passage channel in the bushing comprises a serration formed in an outer surface of the bushing along a length of the bushing. 
     
     
         16 . The method of mounting a flow restrictor according to  claim 10 , wherein the passage in the bushing comprises an inner thread throughout a length of the bushing. 
     
     
         17 . The method of mounting a flow restrictor according to  claim 10 , wherein the passage in the bushing comprises at least one of a slot, a cavity, or a bore throughout a length of the bushing such that said at least one slot, cavity, or bore defines a passage for aerostatic bearing fluid to flow through the bushing. 
     
     
         18 . The method of mounting a flow restrictor according to  claim 10 , wherein the bushing further comprises at least one cavity of cylindrical or conical shape defined therein, wherein said cavity facilitates said step of deforming the bushing.