Air compressor and expander

Abstract

The present invention relates to an air compressor and expander including: a first rotor coupled around a driving shaft; a second rotor coupled around a driven shaft so as to operate in cooperation with the first rotor; a casing adapted to form an air compression or expansion space by the rotation of the first rotor and the second rotor; first and second end covers adapted to close the both end portions of the casing in such a manner as to have the driving shaft and the driven shaft passed therethrough in the axial direction, thereby to have the first rotor or the second rotor disposed between them; a gear part disposed on any one side of the first and second end covers in such a manner as to be coupled around the driving shaft and the driven shaft for transmitting power to the driving shaft and the driven shaft; and a clearance-preventing means disposed at the opposite side to the gear part for preventing the clearance between the end covers and the rotors.

1 - 7 . (canceled) 
   
   
       8 . An air compressor and expander comprising:
 a first rotor coupled around a driving shaft;   a second rotor coupled around a driven shaft so as to operate in cooperation with the first rotor;   a casing adapted to form an air compression or expansion space by the rotation of the first rotor and the second rotor;   first and second end covers adapted to close the both end portions of the casing in such a manner as to have the driving shaft and the driven shaft passed therethrough in the axial direction, thereby to have the first rotor or the second rotor disposed between them;   a gear part disposed on any one side of the first and second end covers in such a manner as to be coupled around the driving shaft and the driven shaft for transmitting power to the driving shaft and the driven shaft; and   a clearance-preventing means disposed at the opposite side to the gear part for preventing clearance between the end covers and the rotors.   
   
   
       9 . The air compressor and expander according to  claim 8 , wherein the clearance-preventing means is adapted to make the ends of the rotors come into close contact with the end covers, such that the first rotor or the second rotor does not have clearance from the end covers. 
   
   
       10 . The air compressor and expander according to  claim 8 , wherein the clearance-preventing means comprises T-shaped bushings, one side of which is coupled to central portion of the rotors and the other side of which contacts with bearings supporting the rotors, and fastening members adapted to the end portions of the driving shaft and the driven shaft thereto to support the other side of the bearings for maintaining a predetermined distance between the gear part and the end cover. 
   
   
       11 . The air compressor and expander according to  claim 8 , wherein the first end cover has a rear cover formed at the outside thereof, and the second end cover has a front cover formed at the outside thereof. 
   
   
       12 . The air compressor and expander according to  claim 8 , wherein the first rotor and the second rotor are formed twisted at a predetermined twisting angle along the axial direction, and the predetermined twisting angle of the first rotor and the second rotor is within a range between 90° and 270°. 
   
   
       13 . The air compressor and expander according to  claim 9 , wherein the first rotor and the second rotor are formed twisted at a predetermined twisting angle along the axial direction, and the predetermined twisting angle of the first rotor and the second rotor is within a range between 90° and 270°. 
   
   
       14 . The air compressor and expander according to  claim 8 , wherein the first rotor and the second rotor are coated with Teflon on the surfaces thereof.