Valve seat insert

Abstract

Embodiments may provide a valve seat insert including a valve seat face. A circumferential contact surface for contacting a cylinder head may be located radially outside and at least partially axially offset from the valve seat face. A discontinuity may be located radially between the valve seat face and the cylinder head and at least partially axially aligned with the valve seat face.

1 . A valve seat insert, comprising:
 a valve seat face;   a circumferential contact surface shaped to contact a cylinder head located radially outside the valve seat face; and   a gap radially between the valve seat face and the circumferential contact surface and at least partially axially aligned with the valve seat face, the gap centrally located along an annular outward surface that extends radially between the circumferential contact surface to the valve seat face.   
     
     
         2 . The valve seat insert of  claim 1 , wherein the gap has a rectangular cross-section. 
     
     
         3 . The valve seat insert of  claim 2 , wherein a valve seat insert material deforms when the valve seat face is contacted by a valve thereby at least partially closing the gap. 
     
     
         4 . The valve seat insert of  claim 2 , wherein the gap is adjacent to an inner surface of a counterbore in the cylinder head. 
     
     
         5 . The valve seat insert of  claim 1 , wherein the gap is an annular gap with a wedge shaped cross-section. 
     
     
         6 . A valve seat insert, comprising:
 an annular-shaped body, the body having a peripheral side-wall and an annular outward surface, the outward surface having at least an inwardly angled inner surface, and an outer surface perpendicular to a central axis of the body, the outer surface including a gap that is spaced away and does not intersect the inwardly angled inner surface, and which is axially aligned with a valve seat face.   
     
     
         7 . The valve seat insert of  claim 6  wherein the gap has a cross-section of an arch. 
     
     
         8 . The valve seat insert of  claim 6  wherein the gap forms an indent having a rectangular cross-section in the outer surface. 
     
     
         9 . The valve seat insert of  claim 8  wherein the indent traverses completely around the outer surface around the central axis of the body. 
     
     
         10 . A valve seat insert, comprising:
 an outer surface having a substantially cylindrical portion configured to fit within and to make contact with a counterbore within a cylinder head and a frusto-conical portion configured to be spaced apart from the counterbore, the frusto-conical portion positioned between a gap and the outer surface.   
     
     
         11 . The valve seat insert of  claim 10 , further comprising a center bore through the insert, and a valve seat face formed in the center bore substantially axially aligned with the frusto-conical portion. 
     
     
         12 . The valve seat insert of  claim 10 , wherein the frusto-conical portion forms a wedge shaped gap between the outer surface and the counterbore. 
     
     
         13 . The valve seat insert of  claim 12 , wherein the valve seat insert includes a central axis and wherein the gap includes a maximum radial thickness of between approximately 0.1 mm and 1.0 mm. 
     
     
         14 . The valve seat insert of  claim 10 , wherein the frusto-conical portion includes an edge spaced from the substantially cylindrical portion wherein the edge is nominally located from an inner surface of the counterbore approximately 0.1 mm to 1.0 mm. 
     
     
         15 . The valve seat insert of  claim 10 , wherein the frusto-conical portion includes an edge spaced from the substantially cylindrical portion wherein the edge is nominally located from an inner surface of the counterbore approximately 0.3 mm. 
     
     
         16 . The valve seat insert of  claim 10 , wherein the gap is substantially closed when a valve makes forcible contact with a valve seat, and wherein valve seat insert is an elastomer. 
     
     
         17 . (canceled) 
     
     
         18 . A valve seat arrangement comprising:
 a counterbore in a cylinder head having an inner surface;   a valve seat insert fitted into the counterbore having an outer surface, the outer surface including:
 a first portion contacting the counterbore inner surface, and 
 a second portion spaced from the counterbore inner surface; and 
   a valve seat face radially inside the valve seat insert outer surface, and axially at least partially aligned with the valve seat insert second portion; and   a gap located along a surface extending from the valve seat face to the second portion spaced from the counterbore inner surface.   
     
     
         19 . The valve seat arrangement of  claim 18 , wherein when in an un-deformed state the valve seat face is part of a curvilinear surface extending beyond the valve seat face which meets the second portion at an annular edge. 
     
     
         20 . The valve seat arrangement of  claim 18 , wherein at least one or more of the following structures are present: the second portion forms an annular notch between the outer surface and the counterbore inner surface, the second portion forms a wedge shaped notch between the outer surface and the counterbore inner surface, and the valve seat insert is made from an elastomeric material.