PISTON UNIT OF THE INTERNAL COMBUSTION ENGINE Russian patent published in 2017 - IPC F02F5/00 

FIELD: machine engineering.

SUBSTANCE: piston unit comprises a compression ring (3), (4), axial expansion ring (5) and the scraper rings (6), (7), (8) located in the piston bore (9). According to an embodiment one axial expansion ring (5) installed between packets compression and oil rings, eliminate gaps between the upper compression ring 3 and the top shelf piston bore (9) and between the lower oil scraper ring (8) and the bottom shelf piston bore (9 ). According to Embodiment 2 axial expansion ring (5) is located between the lower oil scraper ring (8) and the bottom shelf piston bore (9), the inner diameter of the expansion ring (5) is equal to the diameter of the piston bore (9) thus overlaps breakthrough working gas from the bottom piston bore cavity (9) and the engine oil from entering into the bottom cavity bore (9) and further into the combustion chamber.

EFFECT: invention eliminates the gas-dynamic losses, provides effective heat transfer between the piston head overheated and cooled cylinder and cylinder wall forms on the minimum required the thickness of the oil film.

4 cl, 2 dwg