Scroll compressor with captured thrust washer

Abstract

A load transmittal apparatus transfers an axial load to a thrust surface during operation of a scroll compressor.

What is claimed is: 
     
         1 . A scroll compressor including a load transfer apparatus, the compressor including a rotating shaft and a stationary lower bearing member, the load transfer apparatus comprising:
 a central cylindrical hub defined by the stationary lower bearing member, wherein the central hub defines an opening;   a cylindrical bearing configured to seat in the opening, with the cylindrical bearing further configured to receive one end of the shaft; and   a thrust washer disposed in the opening of the central hub and captured axially within the lower bearing member by the cylindrical bearing, wherein an axial load along the centerline of the shaft transmits to the stationary lower bearing member through the thrust washer.   
     
     
         2 . The scroll compressor including a load transfer apparatus of  claim 1 , wherein the thrust washer is fixed axially and rotationally in the opening without a fastener or an adhesive. 
     
     
         3 . The scroll compressor including a load transfer apparatus of  claim 1 , wherein the thrust washer includes a smooth circumference. 
     
     
         4 . The scroll compressor including a load transfer apparatus of  claim 1 , wherein the thrust washer is metal. 
     
     
         5 . The scroll compressor including a load transfer apparatus of  claim 1 , wherein the cylindrical bearing is composed of a matrix of metal and a polymeric layer. 
     
     
         6 . The scroll compressor including a load transfer apparatus of  claim 5 , wherein the cylindrical bearing is lubricated by oil transferring through an orifice defined in the shaft. 
     
     
         7 . The scroll compressor including a load transfer apparatus of  claim 1 , further comprising:
 scroll compressor bodies disposed in a housing, the scroll bodies including a first scroll body and a second scroll body, the first and second scroll bodies having respective bases and respective scroll ribs that project from the respective bases, wherein the scroll ribs mutually engage, the second scroll body being movable relative to the first scroll body for compressing fluid; and   a pilot ring that engages a perimeter surface of the first scroll body to limit movement of the first scroll body in the radial direction, the first scroll body having a first radially-outward-projecting limit tab being configured to limit movement of the first scroll body in at least one of the axial and rotational directions.   
     
     
         8 . The scroll compressor including a load transfer apparatus of  claim 7 , wherein the first scroll body includes the first radially-outward-projecting limit tab and a second radially-outward-projecting limit tab, the first and second radially-outward-projecting limit tabs spaced approximately 180 degrees apart, and wherein the pilot ring has two notches adapted to receive the first and second radially-outward-projecting limit tabs. 
     
     
         9 . The scroll compressor including a load transfer apparatus of  claim 1 , wherein the pilot ring is formed separately from a crankcase, the pilot ring being attached to the crankcase via a plurality of posts extending axially therebetween, the first and second scroll bodies being disposed within the attached pilot ring and crankcase, and further comprising a key coupling that acts upon the second scroll body, the key coupling being disposed within the attached pilot ring and crankcase, and extending into spaces between adjacent posts, and whereby the spaces allow the pilot ring, crankcase, and key coupling to have outer diameters that are approximately equal to the inner diameter of the housing. 
     
     
         10 . A method for transferring axial loading from a rotating shaft in a scroll compressor to a stationary lower bearing member of the scroll compressor, with the rotating shaft having an axial load including the mass of the shaft, a motor rotor, and counterweights of the scroll compressor plus electrical induced load caused by misalignment of the motor rotor and a motor stator, the method comprising:
 depositing a thrust washer at the bottom of an opening in a central cylindrical hub defined by the stationary lower bearing member;   inserting a cylindrical bearing into the opening in the central cylindrical hub;   pressing the cylindrical bearing into the opening axially until the bearing captures the thrust washer into position axially in the opening; and   inserting an end of the shaft into the cylindrical bearing in the opening defined in the central cylindrical hub,   wherein the axial load on the shaft along the centerline of the shaft is transmitted to the stationary lower bearing member through the thrust washer.   
     
     
         11 . The method for transferring axial loading from a rotating shaft in a scroll compressor to a stationary lower bearing member the scroll compressor of  claim 10  wherein the thrust washer is composed of one of a metal and a matrix of metal and a polymeric layer. 
     
     
         12 . The method for transferring axial loading from a rotating shaft in a scroll compressor to a stationary lower bearing member the scroll compressor of  claim 10  wherein the thrust washer is configured with a smooth circumference. 
     
     
         13 . The method for transferring axial loading from a rotating shaft in a scroll compressor to a stationary lower bearing member the scroll compressor of  claim 10 , further comprising lubricating the cylindrical bearing with oil through an orifice in the shaft.