Pressurized balanced sealing system for use on the ring-liner interface

Abstract

Wear is minimized in a reciprocating internal combustion engine operated by fuel with abrasive particles, such as coal based fuel. A flexible diaphragm is used to equalize pressure in a ring pack area having lubricating film with the combustion chamber pressure. This equalization of pressure minimizes the pressure differential which might occur across an oil scraper ring separating the combustion chamber from the ring pack area. This minimizing of the pressure differential prevents or minimizes the passage of abrasive particles behind the oil scraper ring. A second ring, further from the combustion chamber end of the piston than is the oil scraper ring, serves as a high pressure sealing ring and separates the ring pack area from an oil blowby chamber. The second ring provides a predetermined amount of blowby from the ring pack area into the blowby chamber, which is also bounded by a third ring. In order to remove abrasive particles which may get into the ring pack area by deposition on the exposed areas of the cylinder wall, a pump and filter are used to draw in oil from the oil blowby chamber when the piston is in its bottom dead center position and to supply clean oil to the ring pack area.