Large-bore, medium-speed diesel engine having piston crown bowl with acute re-entrant angle

Abstract

A large-bore (at least 180 mm diameter) diesel engine cylinder configuration featuring a piston crown bowl having an acute re-entrant angle and, optionally, an anti-polish ring. The acute re-entrant angle crown bowl involves a maximum radius of the crown bowl exceeding a minimum crown bowl radius, wherein the maximum crown bowl radius is located farther from the squish face than is the minimum crown bowl radius. The acute re-entrant angle crown bowl applied to large-bore, medium-speed diesel engines yields an improvement in performance and emissions characteristics. The anti-polish ring may be integrally formed with the cylinder liner and used in any internal combustion engine.

1 - 10 . (canceled) 
   
   
       11 . An internal combustion engine, comprising: a cylinder defined by a cylinder liner having a liner wall; a piston reciprocal within said cylinder; and an anti-polish ring positioned at an upper portion of said liner wall adjacent said piston when said piston is at a top dead center position in said cylinder; wherein said liner wall and said anti-polish ring are integrally formed as a single piece. 
   
   
       12 . The engine of  claim 11 , wherein said piston has a piston ring package, and wherein said anti-polishing ring has a predetermined height such that said piston ring package does not come into contact with said anti-polishing ring during the reciprocation of said piston; and wherein said anti-polish ring projects a selected distance into said cylinder, and wherein a portion of said piston adjacent said piston crown is recessed a distance substantially equal to said selected distance.