Fluid compressor

Abstract

A fluid compressor 1 comprises a rotation shaft 300 having a compression mechanism 2 and an oil passage 311 , a motor 600 , bearings 401 and 803 , and a centrifugal pump part 900 for supplying oil through the oil passage 311 . The rotation shaft 300 integrally comprises a main shaft portion 302 , a crank pin 301 eccentrically provided to the main shaft portion 302 , and a sub-bearing supported portion 303 having a smaller diameter than the main shaft portion 302 . The oil passage 311 has a first oil passage 311 a extending from a lower end of the sub-bearing supported portion 303 to a lower portion of the main shaft portion 302 , and a second oil passage 311 b that is communicated with the first oil passage 311 a and extends to an upper end of the crank pin 301 . The second oil passage 311 b comprises a passage portion that has a smaller diameter than and is placed at an outer of the first oil passage 311 a , a plurality of the second oil passages 311 b are provided within a plain of said crank pin 311.

1 . A fluid compressor comprising in a sealed container: a compression mechanism for compressing fluid; a rotation shaft connected to said compression mechanism and having an oil passage; a motor for driving said rotation shaft; a main bearing for supporting said rotation shaft above said motor; a sub-bearing for supporting said rotation shaft below said motor; and a centrifugal pump part for supplying oil reserved in a bottom of said sealed container through said oil passage to said compression mechanism and said bearings, 
 wherein said rotation shaft integrally comprises a main shaft portion fixed to a rotor of said motor, a crank pin eccentrically provided at an upper end of said main shaft portion and connected to said compression mechanism, and a small-diameter, sub-bearing supported portion provided at a lower end of said main shaft portion and supported by said sub-bearing;    said oil passage of said rotation shaft comprises a first oil passage extending from a lower end of said sub-bearing supported portion to a lower portion of said main shaft portion, and a second oil passage that is communicated with said first oil passage and extends to an upper end of said crank pin; and    said second oil passage comprises a passage portion that has a smaller diameter than and is placed at an outer of said first oil passage; a plurality of said second oil passages are provided within a plain of said crank pin.    
   
   
       2 . The fluid compressor according to  claim 1 , wherein said first oil passage is provided concentrically with said rotation shaft, and said second passage overlaps said first oil passage so that said second oil passage is communicated with said first oil passage on a peripheral thereof in a substantial length in an axial direction.  
   
   
       3 . The fluid compressor according to  claim 1 , wherein said pump part comprises a pump member in a cylindrical shape attached to the lower end of said rotation shaft, and a pump blade placed inside said pump member; said pump member comprises a portion that is attached to the lower end of said rotation shaft, and a portion extending therefrom downward in which the section area of the fluid passage decreases; and said pump blade has an outer shape that is identical to an inner shape of said pump member, and is press-fitted in said pump member so as to reach a lower end of the inside of said pump member.  
   
   
       4 . The fluid compressor according to  claim 3 , wherein the portion of said pump member in which the section area of the fluid passage decreases has a spherical shape.  
   
   
       5  The fluid compressor according to  claim 1 , wherein said pump part comprises a cylindrical pump member, and said pump member has a cylindrical connecting portion to said rotation shaft and a flat portion opposite to said connecting portion.  
   
   
       6 . The fluid compressor according to  claim 1 , wherein said pump member comprises a cylindrical pump member attached to the lower end of said rotation shaft, and a pump blade placed inside said pump member; and the pump member has a projection for preventing rotation of said pump blade.  
   
   
       7 . The fluid compressor according to  claim 1 , wherein said pump part comprises a cylindrical pump member, and projections of said pump member are configured to sandwich a pump blade.  
   
   
       8 . The fluid compressor according to  claim 1 , wherein said pump part comprises a cylindrical pump member, and said pump member has a connecting portion to said rotation shaft that is connected by a thread having a screw thread whose screw direction is the same as the rotation direction of said rotation shaft.  
   
   
       9 . A fluid compressor comprising in a sealed container: a compression mechanism for compressing fluid; a rotation shaft connected to said compression mechanism and having an oil passage; a motor for driving said rotation shaft; a bearing for supporting said rotation shaft; and a centrifugal pump part for supplying oil reserved in a bottom of said sealed container through said oil passage to said compression mechanism and said bearings, 
 wherein said pump part comprises a cylindrical pump member, and said pump member has a cylindrical connecting portion to said rotation shaft and a flat portion opposite to said connecting portion.    
   
   
       10 . A fluid compressor comprising in a sealed container: a compression mechanism for compressing fluid; a rotation shaft connected to said compression mechanism and having an oil passage; a motor for driving said rotation shaft; a main bearing for supporting said rotation shaft above said motor; a sub-bearing for supporting said rotation shaft below said motor; and a centrifugal pump part for supplying oil reserved in a bottom of said sealed container through said oil passage to said compression mechanism and said bearings, 
 wherein said pump part comprises a double cylindrical pump member, and the outer space in said pump member is open to a lower face of said sub-bearing.