Machine for expanding or compressing compressible media

Abstract

The invention relates to a machine for expanding or compressing compressible media, said machine comprising a machine casing, at least one screw rotor which is arranged in a screw rotor bore in the machine casing and which extends between a low-pressure side and a high-pressure side of the screw rotor bore and which cooperates with the compressible medium, wherein by rotating about a screw rotor axis the at least one screw rotor conveys the substantially gaseous medium either from the low-pressure side to the high pressure side by compressing it, or from the high-pressure side to the low pressure side by expanding it, wherein a motor generator unit is coupled or couplable to the at least one screw rotor, wherein the at least one screw rotor is axially supported by a lubricant support film provided between an end wall surface of said screw rotor bore and a high-pressure end face of said at least one screw rotor in order to prevent contact.

1 . A machine for expanding or compressing compressible media, comprising a machine casing, at least one screw rotor, which is arranged in a screw rotor bore in the machine casing and which extends between a low pressure side and a high pressure side of the screw rotor bore and which cooperates with the compressible medium, wherein by rotating about a screw rotor axis, the at least one screw rotor conveys the substantially gaseous medium either from the low pressure side to the high pressure side by compressing it, or from the high pressure side to the low pressure side by expanding it, wherein said at least one screw rotor is mounted on both sides in the machine casing by way of a respective bearing set, wherein each bearing set has at least one radial acting bearing and at least one of the bearing sets has at least one axially acting bearing that supports the at least one screw rotor to counter an axial displacing movement of said screw rotor from its operating position in the direction of the low pressure side, wherein a motor/generator unit is coupled or couplable to the at least one screw rotor, wherein the at least one screw rotor is axially supported by a lubricant support film provided between an end wall surface limiting said screw rotor bore and the high pressure end face of said at least one screw rotor in order to prevent the high pressure end face from making contact to the end wall surface, and wherein the lubricant support film is maintained between said high pressure end face and said end wall surface by a lubricant supply unit. 
     
     
         2 . The machine according to  claim 1 , wherein the lubricant support film is maintained by supplying lubricant to a support area which is arranged between said high pressure end face of said respective screw rotor and said end wall surface and between an innermost diameter of the high pressure end face and a radially outwardly arranged circular border line. 
     
     
         3 . The machine according to  claim 2 , wherein said circular border line is arranged radially outward from said inner most diameter of said high pressure end face at maximum at a radially innermost root of the screw contour of at least one of said screw rotor. 
     
     
         4 . The machine according to  claim 2 , wherein said innermost diameter of said high pressure end face is defined by an outer diameter of a pin section of said at least one screw rotor, extending beyond said high pressure end face. 
     
     
         5 . The machine according to  claim 1 , wherein said lubricant support film within said support area is maintained by a supply of lubricant to said support area through at least one supply opening of said lubricant supply unit. 
     
     
         6 . The machine according to  claim 1 , wherein said at least one supply opening of said lubricant supply unit is arranged in the high-pressure end face of said at least one screw rotor. 
     
     
         7 . The machine according to  claim 1 , wherein said at least one supply opening of said lubricant supply unit is arranged in the end wall surface. 
     
     
         8 . The machine according to  claim 1 , wherein said at least one supply opening is facing the support area. 
     
     
         9 . The machine according to  claim 1 , wherein said at least one supply opening extends to an area close to said circular border line. 
     
     
         10 . The machine according to  claim 1 , wherein said at least one supply opening is arranged partially outside said support area adjacent to or overlapping with said circular border line. 
     
     
         11 . The machine according to  claim 1 , wherein said at least one supply opening has a longitudinal shape. 
     
     
         12 . The machine according to  claim 1 , wherein said at least one supply opening extends between said circular border line and said inner most diameter. 
     
     
         13 . The machine according to  claim 1 , wherein lubricant is supplied to said lubricant support film in the support area at least at a pressure corresponding to the high-pressure at the high-pressure opening. 
     
     
         14 . The machine according to  claim 1 , whereas said at least one supply opening is arranged in a region of said support area which is opposite to a high-pressure opening in said machine casing at said high-pressure side. 
     
     
         15 . The machine according to  claim 1 , wherein said at least one supply opening is arranged in a region of said support area which is situated on a side of a screw rotor bore of said at least one screw rotor opposite to said high-pressure opening. 
     
     
         16 . The machine according to  claim 1 , wherein said at least one supply opening is arranged in a region of said support area on a side of the bearing pin section of said screw rotor or the screw rotor axis which region is opposite to said high-pressure opening. 
     
     
         17 . The machine according to  claim 1 , wherein said lubricant supply unit comprises a channel extending to said at least one supply opening. 
     
     
         18 . The machine according to  claim 1 , wherein said channel extends through said machine casing to the at least one supply opening arranged in said respective end wall surface. 
     
     
         19 . The machine according to  claim 1 , wherein said channel extends through said at least one screw rotor to the supply opening arranged in said high pressure end face of said at least one screw rotor. 
     
     
         20 . The machine according to  claim 1 , wherein said lubricant supply unit comprises a lubricant reservoir comprising an accumulation of lubricant therein and wherein said lubricant accumulation being connected to said channel extending to said lubricant supply opening. 
     
     
         21 . The machine according to  claim 1 , wherein said lubricant accumulation is exposed to the high pressure of the gaseous medium at the high-pressure opening. 
     
     
         22 . The machine according to  claim 1 , wherein the lubricant accumulation is arranged in a lubricant separator. 
     
     
         23 . The machine according to  claim 22 , wherein said lubricant separator is arranged in said machine casing. 
     
     
         24 . The machine according to  claim 1 , wherein said lubricant supply unit comprises a lubricant pump. 
     
     
         25 . The machine according to  claim 1 , wherein the screw rotors provided with support units acting on the respective pin sections in directions away from high-pressure side towards low-pressure side.