PISTON-TYPE VARIABLE-COMPRESSION INTERNAL COMBUSTION ENGINE Russian patent published in 2000 - IPC

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: compression ratio is changed by changing length of piston stroke for which purpose connecting rod big end is hinge-secured on crankshaft crankpin with eccentric. With crankshaft rotating, eccentric can be turned by its control mechanism around its axis of rotation. Crankpin eccentric consists of at least two segment inserts fitted on crankpin to encircle the latter. Each segment insert has gear segment. These segments, being connected, enclose crankpin. External gear wheel made up of these segments runs inside larger diameter internal gear wheel which is installed on crank-shaft concentrically relative to its axis to turn relative to crankshaft. With engine operating, external gear wheel running over external gear wheel fixed in preset angular position executes one revolution around its own axis to make effective center of connecting rod big end move along elliptical trajectory. Eccentric can be turned within extreme positions corresponding to horizontal ellipse and vertical ellipse. Invention provides possibility of engine operation at variable compression and simultaneous control according to effective modes of operation. EFFECT: increased efficiency and improved smoothness of engine operation. 10 cl, 10 dwg