Compressor

Abstract

An oil pump is provided with helical grooves 142 and 142 ′ carved on the outer periphery of the shaft 125 , with an approximately cup-shaped sleeve 146 loosely fit to the outer periphery of the shaft such that the bottom part of the shaft and the bottom plate of the above-mentioned sleeve are engaged in relatively rotatable manner, and with a rotation suppression means for suppressing the rotation of the sleeve. Thereby, even at the low rotation rate operation, oil is raised reliably to compressor unit, offering a highly reliable compressor operation.

1 - 8 . (canceled)  
     
     
         9 . A compressor comprising: 
 a hermetic container storing oil therein;    an electric motor contained in said hermetic container and including a stator and a rotor;    a compressor unit linked to be driven by said electric motor, said compressor unit including a shaft that extends in a vertical direction and is rotated by said electric motor; and    an oil pump which is formed at a lower end of said shaft and immersed in the oil,    wherein said oil pump includes a helical groove provided in an outer periphery of said shaft, a cup-shaped sleeve rotatably mounted on the lower end of said shaft so as to cover said helical groove with a predetermined clearance defined between said shaft and said sleeve, and a rotation-suppressing element for suppressing rotation of said sleeve.    
     
     
         10 . A compressor in accordance with  claim 9 , wherein said rotation-suppressing element comprises a bracket secured with said stator to fix said sleeve to said stator.  
     
     
         11 . A compressor in accordance with  claim 9 , wherein said rotation-suppressing element comprises a wing formed on an outer periphery of said sleeve to generate a viscous resistance with respect to the oil.  
     
     
         12 . A compressor in accordance with  claim 9 , wherein said rotation-suppressing element comprises a permanent magnet secured to one of said sleeve and said hermetic container, and a member secured to the other of said sleeve and said hermetic container so that a magnetic force of said permanent magnet acts on said member.  
     
     
         13 . A compressor in accordance with  claim 9 , wherein said compressor unit further comprises a shaft support for rotatably supporting said shaft, said shaft having a vertical hole defined therein so as to extend in a vertical direction thereof, said vertical hole communicating an upper end of said helical groove with a clearance between said shaft and said shaft support.  
     
     
         14 . A compressor in accordance with  claim 9 , wherein said sleeve is formed of a synthetic resin.  
     
     
         15 . A compressor in accordance with  claim 9 , wherein said compressor unit is supported elastically in said hermetic container.  
     
     
         16 . A compressor in accordance with  claim 9 , wherein said electric motor is driven at operation frequencies including a frequency lower than a power source frequency.