Patent ID: 7934475

Claim:
An internal combustion engine ( 10 ) comprising cylinders arranged in a housing ( 14 ), a crankshaft ( 18 ) rotatably supported in the housing ( 14 ), pistons ( 16 ) movably disposed in the cylinders and defining in the cylinders combustion chambers, and a device ( 12 ; 12 ′; 12 ″; 12 ′″) for varying a compression ratio of the internal combustion engine ( 10 ), the device ( 12 ; 12 ′, 12 ″, 12 ′″) including, for at least one cylinder: an adjusting structure ( 26 ; 96 ; 100 ; 108 ) for varying one of the effective length of a connecting rod ( 22 ) of the piston ( 16 ), the lift of the crankshaft ( 18 ) and an upper edge ( 94 ) of the cylinders with respect to its position relative to the center of the crankshaft ( 18 ); an operating means ( 28 , 28 ′) mounted in the housing ( 14 ) for varying one of the position and the direction of the adjusting structure ( 26 ; 96 ; 100 ; 108 ); and a drive device ( 38 ) operated by the crankshaft ( 18 ) and including a adjusting shaft ( 30 ) carrying the operating means ( 28 , 28 ′), and a coupling mechanism ( 40 ) with an integrated brake function, by which the adjusting shaft ( 30 ) can either be placed in operative connection with the crankshaft ( 18 ) or can be locked in a particular position for maintaining a given compression ratio of the engine.