Dual thrust bearing for a turbocharger

Abstract

A dual thrust bearing is disclosed. The dual thrust bearing may have a shell. The shell may extend from a compressor end to a turbine end opposite the compressor end. The shell may have a shell bore extending from the compressor end to the turbine end. The shell bore may be configured to receive a journal bearing. The shell may also have a first thrust bearing face disposed adjacent the compressor end. In addition, the shell may have a second thrust bearing face disposed adjacent the turbine end.

What is claimed is: 
     
         1 . A dual thrust bearing, comprising:
 a shell extending from a compressor end to a turbine end opposite the compressor end, the shell including:
 a shell bore extending from the compressor end to the turbine end, the shell bore being configured to receive a journal bearing; 
 a first thrust bearing face disposed adjacent the compressor end; and 
 a second thrust bearing face disposed adjacent the turbine end. 
   
     
     
         2 . The dual thrust bearing of  claim 1 , wherein
 the shell further includes a flange disposed adjacent the compressor end,   the flange is configured to attach the dual thrust bearing to a bearing housing, and   the first thrust bearing face is disposed on the flange.   
     
     
         3 . The dual thrust bearing of  claim 2 , wherein the first thrust bearing face includes a plurality of thrust pad sections disposed circumferentially on the first thrust bearing face, each thrust pad section extending circumferentially from a leading end to a trailing end and extending radially from an inner wall to an outer wall. 
     
     
         4 . The dual thrust bearing of  claim 3 , wherein the thrust pad sections include:
 a first thrust pad section;   a second thrust pad section; and   a drain separating the first thrust pad section from the second thrust pad section, the drain extending radially from adjacent the inner wall to a flange outer surface.   
     
     
         5 . The dual thrust bearing of  claim 4 , wherein the drain has a first axial depth adjacent the inner wall and a second axial depth smaller than the first axial depth adjacent the outer surface of the flange. 
     
     
         6 . The dual thrust bearing of  claim 3 , the thrust pad section includes:
 a slot disposed adjacent the leading end;   a thrust pad disposed adjacent the trailing end; and   a ramp disposed between the slot and the thrust pad.   
     
     
         7 . The dual thrust bearing of  claim 6 , wherein the ramp has a first axial depth adjacent the slot and a second axial depth smaller than the first axial depth adjacent the thrust pad. 
     
     
         8 . The dual thrust bearing of  claim 6 , wherein the thrust pad section further includes a rim extending circumferentially along the outer wall from adjacent the slot to adjacent the thrust pad. 
     
     
         9 . The dual thrust bearing of  claim 6 , wherein
 the slot extends radially from an inner slot end disposed adjacent the inner wall to an outer slot end disposed adjacent the outer wall, and   the slot includes an inlet disposed adjacent the inner slot end, the inlet being configured to dispense a metered amount of oil into the slot.   
     
     
         10 . A bearing assembly, comprising:
 a shell extending from a compressor end to a turbine end opposite the compressor end;   a shell bore extending from the compressor end to the turbine end;   a first thrust bearing face disposed on the compressor end of the shell;   a second thrust bearing face disposed on the turbine end of the shell; and   a journal bearing disposed within the shell bore.   
     
     
         11 . The bearing assembly of  claim 10 , further including:
 an impeller cap having a cap portion, a shaft portion disposed within the journal bearing, an impeller cap bore, and an impeller step face;   a shaft disposed within the impeller cap bore; and   a thrust washer disposed on the shaft adjacent the turbine end.   
     
     
         12 . The bearing assembly of  claim 11 , wherein
 the impeller step face is disposed opposite the first thrust bearing face and axially separated from the first thrust bearing face by a first gap; and   the thrust washer has a thrust washer front face disposed opposite the second thrust bearing face and being axially separated from the second thrust bearing face by a second gap.   
     
     
         13 . The bearing assembly of  claim 10 , further including a flange configured to mount the shell to a bearing housing, the first thrust bearing face being disposed on a portion of the flange. 
     
     
         14 . The bearing assembly of  claim 13 , further including:
 a wall of the bearing housing, the wall having a front face and a rear face;   a fastener hole extending from the front face to the rear face;   a backing plate disposed adjacent the rear face; and   a fastener extending through the flange and the wall and threadingly engaged with the backing plate to mount the shell to the bearing housing.   
     
     
         15 . The bearing assembly of  claim 14 , further including:
 an alignment cavity in the wall, the alignment cavity extending from the front face towards the rear face; and   an alignment pin extending from a knob portion to a stud portion, the knob portion being received in the alignment cavity and the stud portion being received in a pin recess in the journal bearing.   
     
     
         16 . The bearing assembly of  claim 13 , wherein the first thrust bearing face includes a plurality of thrust pad sections disposed circumferentially on the first thrust bearing face, each thrust pad section extending circumferentially from a leading end to a trailing end and extending radially from an inner wall to an outer wall. 
     
     
         17 . The bearing assembly of  claim 16 , wherein the thrust pad section includes:
 a slot disposed adjacent the leading end;   a thrust pad disposed adjacent the trailing end; and   a ramp disposed between the slot and the thrust pad.   
     
     
         18 . The bearing assembly of  claim 17 , wherein the ramp has a generally flat surface disposed at an angle relative to the thrust pad. 
     
     
         19 . The bearing assembly of  claim 16 , wherein the thrust pad sections include:
 a first thrust pad section;   a second thrust pad section; and   a drain separating the first thrust pad section from the second thrust pad section, the drain extending radially from adjacent the inner wall to a flange outer surface.   
     
     
         20 . A turbocharger, comprising:
 a turbine housing;   a turbine wheel disposed within the turbine housing and configured to be rotated by exhaust received from an engine;   a compressor housing;   a shaft attached to the turbine wheel, the shaft extending from the turbine housing to the compressor housing;   a compressor impeller disposed within the compressor housing, the compressor impeller being configured to be driven by the turbine wheel via the shaft;   a bearing housing connecting the turbine housing with the compressor housing;   a bearing assembly disposed within the bearing housing, the bearing assembly including:
 a shell extending from a compressor end to a turbine end; 
 a shell bore in the shell extending from the compressor end to the turbine end; 
 a journal bearing extending from the compressor end to the turbine end, the journal bearing being disposed within the shell bore; 
 a thrust washer disposed on the shaft adjacent the turbine end; 
 a first thrust bearing face disposed on the compressor end of the shell, the first thrust bearing face being axially separated from the compressor impeller by a first gap; and 
 a second thrust bearing face disposed on the turbine end of the shell, the second thrust bearing face being axially separated from the thrust washer by a second gap.