Multi-stage piston compressor

Abstract

A multi-stage piston compressor is provided with at least two piston-cylinder units, which respectively comprise a separate linear drive for moving the piston. A control device is also provided, which is designed in a manner such that the linear drives may be controlled individually with regard to speed and stroke.

1 . A multi-stage piston compressor comprising at least two piston-cylinder units ( 2 ,  4 ,  6 ), each of the units having a separate linear drive ( 14 ,  16 ,  18 ) for moving the piston, and a control device ( 28 ) designed such that the linear drives ( 14 ,  16 ,  18 ) are controllable individually in speed and stroke. 
   
   
       2 . The multi-stage piston compressor according to  claim 1 , wherein the control device ( 28 ) is designed such that a stage pressure ratio of the piston-cylinder units ( 2 ,  4 ,  6 ) may be changed by the individual control of the linear drives ( 14 ,  16 ,  18 ) of the at least two piston-cylinder units ( 2 ,  4 ,  6 ). 
   
   
       3 . The multi-stage piston compressor according to  claim 1 , wherein the at least two piston-cylinder units ( 2 ,  4 ,  6 ) are designed such that cylinders ( 12 ) of the respective piston-cylinder units have differently large inner cross sections. 
   
   
       4 . The multi-stage piston compressor according to  claim 1 , wherein the linear drives ( 14 ,  16 ,  18 ) have respective rotating drive motors ( 20 ,  22 ,  24 ) and respective spindle drives, which convert a rotational movement of the drive motor ( 20 ,  22 ,  24 ) into a linear movement for respective pistons ( 10 ). 
   
   
       5 . The multi-stage piston compressor according to  claim 1 , wherein the piston-cylinder units ( 2 ,  4 ,  6 ) are designed as dry-running. 
   
   
       6 . The multi-stage piston compressor according to  claim 1 , further comprising respective intermediate coolers ( 52 ,  54 ,  56 ) arranged between the at least two piston-cylinder units ( 2 ,  4 ,  6 ). 
   
   
       7 . The multi-stage piston compressor according to  claim 1 , wherein the piston-cylinder units ( 2 ,  4 ,  6 ) are designed respectively as double-stroke. 
   
   
       8 . The multi-stage piston compressor according to  claim 1 , further comprising a switch-over valve ( 46 ,  48 ) arranged on an exit side of at least one of the first piston-cylinder units ( 2 ,  4 ), wherein the switch-over valve located at an exit-side flow path may be switched between a subsequent second piston-cylinder unit ( 4 ,  6 ) and an exit conduit ( 50 ).