Turbocharger thrust bearing and manufacturing method

Abstract

A thrust bearing, particularly for a turbocharger, having unique configurations on the thrust pad faces, including free-form curvatures or non-linear configurations defined by a geometric equation. The thrust pad faces can be configured by a programmed linear actuator system and cutting tool.

What is claimed is: 
     
         1 . A fluid-film thrust bearing comprising:
 a disc member having a first surface on one side and a second surface on the opposite side from said first surface;   said first surface having a plurality of thrust pad members thereon, each of said thrust pad members having an outer axial oriented surface;   each of said outer surfaces having a curved profile configuration on at least a portion thereof;   said curved profile configurations being defined by a non-linear geometric equation.   
     
     
         2 . The fluid-film thrust bearing as set forth in  claim 1  further comprising a central opening in said disc member, wherein said disc member can be positioned on a shaft member, and wherein said thrust pad members have a wedge-shaped configuration. 
     
     
         3 . The fluid-film thrust bearing as set forth in  claim 1  wherein said pad members are arranged in a circular orientation on said first surface, and said thrust bearing is a turbocharger thrust bearing. 
     
     
         4 . The fluid-film thrust bearing as set forth in  claim 1  further comprising a plurality of fluid channels positioned on said first surface, wherein a fluid can be applied to said pad members on said first surface. 
     
     
         5 . The fluid-film thrust bearing as set forth in  claim 1  further comprising a plurality of thrust pad members on said second surface. 
     
     
         6 . The fluid-film thrust bearing as set forth in  claim 5  wherein each of said thrust pad members on said second surface has a wedge-shape configuration with an outer surface having a curved profile configuration. 
     
     
         7 . The fluid-film thrust bearing as set forth in  claim 6  wherein said curved profile configures on the outer surfaces of said thrust pad members on said second surface is defined by the same equation defining the curved profile configurations on the outer surfaces of the thrust pad members on said first surface. 
     
     
         8 . A fluid-film thrust bearing comprising:
 a disc member having a first surface on one side and a second surface on the opposite side from said first surface;   said first surface having a plurality of thrust pad members thereon, each of said thrust pad members having an outer axial oriented surface;   each of said outer surfaces having a curved profile configuration on at least a portion thereof;   said curved profile configuration being free-formed defined by the equation h=a(x) k ; where “h” is the pad elevation, relative to a datum located on the pad, “a” is a constant, “x” is a point location on the thrust pad surface; and “k” is the power.   
     
     
         9 . The fluid-film thrust bearing as set forth in  claim 8  further comprising a plurality of thrust pad members on said second surface. 
     
     
         10 . The fluid thrust bearing as set forth in  claim 8  wherein “k” is a power greater than 1. 
     
     
         11 . A method of forming thrust pads on a first surface of a thrust bearing, said method comprising:
 providing a thrust bearing with a plurality of thrust pads integrally formed on a first surface of said thrust bearing, each of said thrust pads having a front face;   selecting or inputting a thrust pad profile;   providing an apparatus comprising,
 an actuator, 
 a cutting tool coupled to the actuator for machining the front face of each of said thrust pads, and 
 a controller for directing the actuator; and 
   machining the thrust pad profile on the front face of the thrust pads on said first surface of the thrust bearing.   
     
     
         12 . The method as set forth in  claim 11  wherein said thrust bearing is a turbocharger thrust bearing. 
     
     
         13 . The method as set forth in  claim 11  wherein the machining of the front faces of said thrust pads provide a non-linear taper profile defined by a geometric equation on said front faces. 
     
     
         14 . The method as set forth in  claim 11  wherein the machining of the front faces of said thrust pads provides a free-form profile on said front faces. 
     
     
         15 . The method as set forth in  claim 11  further comprising providing a second plurality of thrust pads on a second surface of said thrust bearing opposite said first surface, each of said second plurality of thrust pads having a front face; and
 machining a thrust pad profile on the front face of each of said second plurality of thrust pads. 
 
     
     
         16 . The method as set forth in  claim 11  further comprising the step of selecting or inputting a thrust pad profile which includes variations in said profile during use.