Outer housing for a hydraulic lash adjuster with tapered oil feed annulus

Abstract

A hydraulic lash adjuster is provided. The hydraulic lash adjuster includes an outer housing having an annular body with an open first axial end, a closed second axial end, a radially inner wall defining an axial bore, and a radially outer wall. The radially outer wall includes a first annular groove located adjacent to the first axial end, and a second annular groove located adjacent to the second axial end. A first port is located in the first annular groove, and a second port is located in the second annular groove. A radially outer surface of the first annular groove tapers radially inwardly between a first axial end and a second axial end.

What is claimed is: 
     
         1 . A hydraulic lash adjuster comprising:
 an outer housing having an annular body with an open first axial end, a closed second axial end, a radially inner wall defining an axial bore, and a radially outer wall, the radially outer wall includes a first annular groove located adjacent to the first axial end;   a first port located in the first annular groove; and   a radially outer surface of the first annular groove tapers radially inwardly between a first axial end and a second axial end.   
     
     
         2 . The hydraulic lash adjuster of  claim 1 , the outer housing further comprising a second annular groove located adjacent to the second axial end, and a second port located in the second annular groove. 
     
     
         3 . The hydraulic lash adjuster of  claim 1 , wherein the first port is located adjacent to the second axial end of the first annular groove. 
     
     
         4 . The hydraulic lash adjuster of  claim 1 , wherein the radially outer surface of the first annular groove tapers radially inwardly by approximately 3 degrees between the first axial end and the second axial end. 
     
     
         5 . The hydraulic lash adjuster of  claim 1 , wherein a thickness of the annular body at the first axial end of the first annular groove is greater than a thickness of the annular body at the second axial end of the first annular body. 
     
     
         6 . The hydraulic lash adjuster of  claim 1 , wherein a thickness of the annular body decreases from approximately 1.25 mm at the first axial end of the first annular groove to approximately 0.6 mm at the second axial end of the first annular groove. 
     
     
         7 . The hydraulic lash adjuster of  claim 1 , wherein the first annular groove has an axial length of approximately 6.0 mm. 
     
     
         8 . The hydraulic lash adjuster of  claim 1 , wherein the first annular groove has a radial depth of approximately 0.45 mm. 
     
     
         9 . A hydraulic lash adjuster comprising:
 an outer housing having an annular body with an open first axial end, a closed second axial end, a radially inner wall defining an axial bore, and a radially outer wall, the radially outer wall includes a first annular groove located adjacent to the first axial end;   a first port located in the first annular groove; and   a radially outer surface of the first annular groove tapers radially inwardly between a first axial end and a center-point of the first port.   
     
     
         10 . The hydraulic lash adjuster of  claim 9 , the outer housing further comprising a second annular groove located adjacent to the second axial end, and a second port located in the second annular groove. 
     
     
         11 . The hydraulic lash adjuster of  claim 9 , wherein the first port is located adjacent to a second axial end of the first annular groove. 
     
     
         12 . The hydraulic lash adjuster of  claim 9 , wherein a thickness of the annular body decreases from approximately 1.25 mm at the first axial end of the first annular groove to approximately 0.65 mm at the center-point of the first port. 
     
     
         13 . A valve train for an internal combustion engine comprising:
 a cylinder head including a bore and a plurality of hydraulic fluid galleries;   an outer housing positioned in the bore of the cylinder head and having an annular body with an open first axial end, a closed second axial end, a radially inner wall defining an axial bore, and a radially outer wall, the radially outer wall includes a first annular groove located adjacent to the first axial end;   a first port located in the first annular groove and in communication with a first hydraulic fluid gallery of the plurality of hydraulic fluid galleries;   a radially outer surface of the first groove tapers radially inwardly between a first axial end and a second axial end;   a plunger that is axially displaceable within the axial bore of the annular body; and   a rocker arm assembly in abutment with the plunger that is actuatable between a first and second valve lift mode via a hydraulic fluid feed from the plunger.   
     
     
         14 . The valve train of  claim 13 , the outer housing further comprising a second annular groove located adjacent to the second axial end, and a second port located in the second annular groove and in communication with a second hydraulic fluid gallery of the plurality of hydraulic fluid galleries.