Method and Apparatus for Rotating Sleeve Engine Hydrodynamic Seal

Abstract

An improved sealing system for a poppet valve rotating sleeve internal combustion engine with rotating liners. A hydrodynamic face seal assembly includes a spring pre-load assembly provides a uniform loading to a primary sealing ring. A secondary seal is provided between the primary sealing ring and the cylinder head. Hydrodynamic face seal features are provided either on the mating face of the primary sealing ring or on the annular face of the rotating liner. The hydrodynamic face seal features include an inner sealing zone, and an outer loading zone with a plurality of hydrodynamic lift pads, and dam features which create converging surfaces. A lubricant is provided to the annular face of the rotating liner, so that a lubricant layer can be maintained between the primary sealing ring mating face and the rotating liner.

What is claimed is: 
     
         1 - 18 . (canceled) 
     
     
         19 . A sealing system for a poppet valve rotating sleeve internal combustion engine, the engine comprising a rotating liner which may be rotated during the operation of the engine, and a cylinder head, the improved sealing system comprising:
 a hydrodynamic face seal assembly comprising:
 a primary sealing ring comprising a mating face, 
 a mechanical pre-load assembly which provides a uniform loading to the primary sealing ring, and 
 a secondary seal between the primary sealing ring and the cylinder head; 
   an annular face of the rotating liner positioned in proximity to the mating face of the primary sealing ring;   hydrodynamic face seal features provided on the mating face of the primary sealing ring or provided on the annular face of the rotating liner, the hydrodynamic face seal features comprising:
 an inner sealing zone, and 
 an outer loading zone, comprising:
 a plurality of hydrodynamic tilted pads or step pads, and 
 dam features, such that the tilted pads or step pads create converging surfaces, and tilted pad or step pad performance is enhanced by the dam features when cylinder pressure rate of change is high and a lubricant layer thickness is reducing. 
 
   
     
     
         20 . The sealing system of  claim 19  further comprising at least one lubricant supply hole through the rotating liner extending from a region of high lubricant pressure to the annular face of the rotating liner, whereby lubricant may be provided to the interface of the annular face of the rotating liner and the mating face of the primary sealing ring. 
     
     
         21 . The sealing system of  claim 19  wherein the mechanical pre-load assembly comprises:
 a spring washer that is deformable when pre-loaded; 
 a spring fulcrum in mechanical communication with the cylinder head; and 
 a spring base in mechanical communication with the primary sealing ring. 
 
     
     
         22 . The sealing system of  claim 19  wherein the mechanical pre-load assembly comprises:
 a plurality of coil springs, wherein each coil spring of the plurality of coil springs is in mechanical communication with the cylinder head and the primary sealing ring. 
 
     
     
         23 . The sealing system of  claim 19  wherein the mechanical pre-load assembly comprises:
 a Belleville washer spring that is deformable when pre-loaded, wherein the Belleville washer spring is in mechanical communication with the cylinder head; and 
 a spring base in mechanical communication with the Belleville washer spring and the primary sealing ring. 
 
     
     
         24 . The sealing system of  claim 19  wherein the secondary seal comprises at least one material selected from polymer and Teflon. 
     
     
         25 . The sealing system of  claim 19  wherein the primary sealing ring comprises at least one material selected from brass and beryllium copper. 
     
     
         26 . The sealing system of  claim 19  wherein the hydrodynamic face seal features further comprise an inside dam. 
     
     
         27 . The sealing system of  claim 19  wherein the hydrodynamic face seal features further comprise an outside dam. 
     
     
         28 . The sealing system of  claim 19  wherein the hydrodynamic face seal features further comprise an inside and an outside dam. 
     
     
         29 . A method for sealing for a poppet valve rotating sleeve internal combustion engine, the engine comprising a rotating liner which may be rotated during the operation of the engine, and a cylinder head, the method comprising:
 providing a rotating liner engine with a sealing system comprising:
 a hydrodynamic face seal assembly comprising:
 a primary sealing ring comprising a mating face, 
 a mechanical pre-load assembly that provides a uniform loading to the primary sealing ring, and 
 a secondary seal between the primary sealing ring and the cylinder head, and 
 
 an annular face of the rotating liner positioned in proximity to the mating face of the primary sealing ring; 
   providing hydrodynamic face seal features on either the mating face of the primary sealing ring or on the annular face of the rotating liner, the hydrodynamic face seal features comprising:
 an inner sealing zone, and 
 an outer loading zone, such that the loading zone comprises:
 an outer loading zone, such that the loading zone comprises a plurality of hydrodynamic tilted pads or step pads, and 
 dam features, such that the tilted pads or step pads create converging surfaces, and tilted pad or step pad performance is enhanced by the dam features when cylinder pressure rate of change is high and a lubricant layer thickness is reducing; and 
 
   generating, with the mechanical pre-load assembly, a pre-load on the primary sealing ring.   
     
     
         30 . The sealing method of  claim 29  further comprising providing lubrication to the annular face of the rotating liner via at least one hole through the rotating linter extending from a region of high pressure lubricant to the annular face, whereby lubricant may be provided to the interface of the annular face of the rotating liner and the mating face of the primary sealing ring. 
     
     
         31 . The sealing method of  claim 29  wherein providing a rotating liner engine with a sealing system further comprises providing:
 a spring washer that is deformable when pre-loaded; 
 a spring fulcrum in mechanical communication with the cylinder head; and 
 a spring base in mechanical communication with the primary sealing ring. 
 
     
     
         32 . The sealing method of  claim 29  wherein providing a rotating liner engine with a sealing system further comprises providing:
 a plurality of coil springs, wherein each coil spring of the plurality of coil springs is in mechanical communication with the cylinder head and the primary sealing ring. 
 
     
     
         33 . The sealing method of  claim 29  wherein providing a rotating liner engine with a sealing system further comprises providing:
 a Belleville washer spring that is deformable when pre-loaded, wherein the Belleville washer spring is in mechanical communication with the cylinder head; and 
 a spring base in mechanical communication with the Belleville washer spring and the primary sealing ring. 
 
     
     
         34 . The sealing method of  claim 29  wherein providing dam features further comprises providing outside dams relative to the lift pads. 
     
     
         35 . The sealing method of  claim 29  wherein providing dam features further comprises providing inside dams relative to the lift pads. 
     
     
         36 . The sealing method of  claim 29  wherein providing dam features further comprises providing inside dams and outside dams relative to the lift pads. 
     
     
         37 . A poppet valve rotating sleeve internal combustion engine, the engine comprising:
 a rotating liner that is rotatable during the operation of the engine,   a piston positioned for translational motion within the rotating liner,   a cylinder head, and   a sealing system for sealing the cylinder head and the rotating liner comprising:
 a hydrodynamic face seal assembly comprising:
 a primary sealing ring comprising a mating face, 
 a mechanical pre-load assembly which provides a uniform loading to the primary sealing ring, and 
 a secondary seal between the primary sealing ring and the cylinder head; 
 
   an annular face of the rotating liner positioned in proximity to the mating face of the primary sealing ring;   hydrodynamic face seal features provided on the mating face of the primary sealing ring or provided on the annular face of the rotating liner, the hydrodynamic face seal features comprising:
 an inner sealing zone, and 
 an outer loading zone, such that the loading zone comprises:
 a plurality of hydrodynamic tilted pads or step pads, and 
 dam features, such that the tilted pads or step pads create converging surfaces, and tilted pad or step pad performance is enhanced by the dam features when cylinder pressure rate of change is high and a lubricant layer thickness is reducing, wherein the dam features comprise an outside dam at the outside of the step pad. 
 
   
     
     
         38 . The poppet valve rotating sleeve internal combustion engine of  claim 19 , further comprising at least one lubricant supply for maintaining a lubricant layer between the face and the rotating liner, and wherein the outside dam generates squeeze film action on the outside of the dam at about the same degree as the inner sealing zone, and the dam features further comprise an inside dam at the inside of the step pad.