METHOD OF SEALING RADIAL CLEARANCE BETWEEN WORKING SURFACE OF CYLINDER AND OUTER CYLINDRICAL SURFACE OF PISTON AND DESIGN OF PISTON Russian patent published in 2007 - IPC F02F3/00 

FIELD: mechanical engineering; internal combustion engines.

SUBSTANCE: invention relates to pistons sealed by elastic rings. According to proposed method of sealing, elastic rings are fitted in piston grooves to seal radial clearance between working surface of cylinder and outer cylindrical surface of piston in internal combustion engines. Sector of radial clearance whose center is located on line of application of normal gas pressure force to piston pin is sealed by forced alignment of outer cylindrical surface of piston over entire length of its generatrix with working surface of cylinder of means of spring-loaded pushers and subsequent lapping of said aligned surfaces with the limits of angle of tight fitting of outer cylindrical surface of piston on working surface of cylinder. Piston contains elastic rings installed in piston grooves and spring-loaded insert. Main cylindrical space is made in piston body, axis of said space arranged square to axis of piston being bisector of angle "α" where "α" is angle of sector of radial clearance sealed by forced alignment of surfaces of piston and cylinder at α>γ where "γ" is angle of aperture of exhaust or scavenging port of cylinder. Said main cylindrical space is limited from side of force-aligned surfaces by inner wall piston, and from opposite side it forms port opening lower than elastic sealing rings to working wall of cylinder. Central section of main cylindrical space is transformed into cheeks arranged parallel to each other relative to axis of piston and preventing axial displacement of piston pin. Piston grooves for elastic sealing rings are made with undercut for angle "α", and elastic rings are made in form of grooves in space between elastic rings in piston body. Small cylindrical spaces made from opposite side from force-aligned surfaces accommodate spring-loaded pushers thrusting from one side against cylinder wall, and from other side, through springs, against piston. Main cylindrical pusher is installed for axial and radial displacement in main cylindrical space. Space with hole for fitting piston pin and head of connecting rod on piston pin is formed ion central part of main pusher. Port of main cylindrical space is provided with slots to pass piston pin, and opening is made in piston skirt to pass connecting rod at assembling, and groove is made from side of end face of main pusher adjoining inner wall of piston to install spring which thrusts against walls of piston and pusher fixing it on working surface of cylinder.

EFFECT: enlarged functional capabilities of proposed method of sealing and piston.

3 cl, 7 dwg