Lubricant supply passage for compressor

Abstract

A fluid machine includes a first rotor rotatable about a first axis, a second rotor rotatable about a second axis, a casing for supporting said first rotor and said second rotor, a sump having a volume of lubricant contained therein, a first lubricant passage for supplying lubricant from the sump to a dynamic interface associated with the first rotor, and a second lubricant passage for supplying lubricant from the sump to a dynamic interface associated with the second rotor. A pressure differential created within the fluid machine supplies the lubricant from the sump to the first lubricant passage and the second lubricant passage.

1 . A fluid machine comprising:
 a first rotor rotatable about a first axis;   a second rotor rotatable about a second axis;   a casing for supporting said first rotor and said second rotor;   a sump having a volume of lubricant contained therein;   a first lubricant passage for supplying lubricant from the sump to a dynamic interface associated with the first rotor; and   a second lubricant passage for supplying lubricant from the sump to a dynamic interface associated with the second rotor, wherein a pressure differential created within the fluid machine supplies the lubricant from the sump to the first lubricant passage and the second lubricant passage.   
     
     
         2 . The fluid machine of  claim 1 , wherein during operation of the fluid machine, the pressure differential is formed between a high pressure adjacent at least one end of the casing and low pressure at a central location of the first rotor and the second rotor. 
     
     
         3 . The fluid machine of  claim 1 , wherein said lubricant is supplied from said sump to said first lubricant passage and said second lubricant passage simultaneously. 
     
     
         4 . The fluid machine of  claim 1 , wherein said first rotor is rotatably mounted to the casing without roller element bearings. 
     
     
         5 . The fluid machine of  claim 1 , wherein the first rotor includes a first shaft rotatably mounted to the casing, wherein at least one surface of the casing and the first shaft define the dynamic interface associated with the first rotor. 
     
     
         6 . The fluid machine of  claim 5 , wherein the at least one surface of the casing arranged in direct contact with the first shaft functions as a bearing. 
     
     
         7 . The fluid machine of  claim 6 , wherein the at least one surface of the casing arranged in direct contact with the first shaft includes a first surface arranged in direct contact with a portion the first shaft adjacent a first end, and a second surface arranged in direct contact with a portion the first shaft adjacent a second end. 
     
     
         8 . The fluid machine of  claim 7 , wherein the first lubricant passage includes a first portion for supplying lubricant to the first surface and a second portion, distinct from the first portion, for supplying lubricant to the second surface, wherein lubricant is supplied to both the first portion and the second portion simultaneously. 
     
     
         9 . The fluid machine of  claim 5 , wherein the first lubricant passage further comprises:
 a cavity formed in a portion of the casing adjacent the first shaft;   a passage extending axially through at least a portion of the first shaft;   at least one radial hole coupling the cavity and the passage; and   a groove extending from the cavity to an interior of a compression pocket formed between the first rotor and the second rotor and the casing.   
     
     
         10 . The fluid machine of  claim 9 , wherein the first lubricant passage further comprises:
 a counter bore formed at the interface between the casing and the compression pocket.   
     
     
         11 . The fluid machine of  claim 5 , wherein the first lubricant passage comprises:
 a groove extending from the sump to an interior of a compression pocket formed between the first rotor and the second rotor and the casing.   
     
     
         12 . The fluid machine of  claim 5 , wherein the second rotor further comprises:
 a second shaft supported by the casing; and   a working portion rotatable relative to the second shaft, wherein the second shaft and the working portion define the dynamic interface associated with the second rotor.   
     
     
         13 . The fluid machine of  claim 12 , wherein the second lubricant passage further comprises:
 a first passage extending axially through at least a portion of the second shaft;   a second passage formed in an outer periphery of the second shaft; and   at least one radial hole coupling the first passage and the second passage.   
     
     
         14 . The fluid machine of  claim 13 , wherein the second passage extends axially such that a first end of the second passage is fluidly coupled to a first portion of the casing and a second, opposite end of the second passage is fluidly coupled to a second portion of the casing. 
     
     
         15 . The fluid machine of  claim 1 , wherein a counter bore is formed in the casing where at least one of the first lubricant passage and the second lubricant passage enters a compression pocket formed between the first rotor and the second rotor. 
     
     
         16 . The fluid machine of  claim 15 , further comprising a recess is formed in the casing in fluid communication with the counter bore, the recess being arranged at an angle towards an interface between the first rotor and the second rotor. 
     
     
         17 . The fluid machine of  claim 16 , wherein at least one of an angle, length, width, and depth of the recess is optimized to control a flow of lubricant to the compression pocket. 
     
     
         18 . A method of lubricating one or more dynamic interfaces of a fluid machine comprising:
 supplying lubricant from a sump to a dynamic interface associated with a first rotor of the fluid machine via a first lubricant passage; and   supplying lubricant from a sump to a dynamic interface associated with a second rotor of the fluid machine via a second lubricant passage, the second lubricant passage being distinct from the first lubricant passage;   wherein supplying lubricant to the dynamic interface associated with the first rotor and the dynamic interface associated with the second rotor occurs automatically in response to a pressure differential created within the fluid machine during operation of the fluid machine.   
     
     
         19 . The method of  claim 18 , wherein supplying lubricant from a sump to a dynamic interface associated with a first rotor and supplying lubricant from a sump to a dynamic interface associated with a second rotor occurs simultaneously. 
     
     
         20 . The method of  claim 18 , wherein supplying lubricant from a sump to a dynamic interface associated with a first rotor and supplying lubricant from a sump to a dynamic interface associated with a second rotor occurs without a pump or control valve. 
     
     
         21 . The method of  claim 18 , wherein supplying lubricant from a sump to a dynamic interface associated with a first rotor further comprises:
 supplying lubricant via a first passage to a first bearing surface, the first passage extending through an opening formed in a first shaft of the first rotor; and   supplying lubricant via a second passage to a second bearing surface.   
     
     
         22 . The method of  claim 18 , further comprising supplying lubricant from the dynamic interface associated with a first rotor and the dynamic interface associated with a second rotor to a compression pocket formed between the first rotor and the second rotor.