Patent ID: 8220422

Claim:
A reciprocating variable compression ratio engine comprising at least: a casing ( 100 ); a crankshaft ( 9 ); a connecting rod ( 6 ); a wrist pin ( 60 ); a cylinder ( 110 ); a piston ( 2 ) movable within said cylinder ( 110 ), said piston ( 2 ) comprising a first piston rack ( 31 ) and a second piston rack ( 32 ), said first piston rack ( 31 ) having teeth at opposite direction than the direction of the teeth of said second piston rack ( 32 ); a first control rack ( 71 ) and a second control rack ( 72 ); a first gear wheel ( 51 ) and a second gear wheel ( 52 ), said first gear wheel ( 51 ) and said second gear wheel ( 52 ) being pivotally mounted at one end of said connecting rod ( 6 ) by said wrist pin ( 60 ), said first gear wheel ( 51 ) being meshed at one side to said first piston rack ( 31 ) and at its opposite side to said first control rack ( 71 ), said second gear wheel ( 52 ) being meshed at one side to said second piston rack ( 32 ) and at its opposite side to said second control rack ( 72 ); a first rolling surface ( 710 ) and a second rolling surface ( 720 ); a first roller ( 510 ) secured to said first gear wheel ( 51 ), said first roller ( 510 ) having diameter substantially equal to the pitch circle diameter of said first gear wheel ( 51 ), said first roller ( 510 ) abutting on said first rolling surface ( 710 ); a second roller ( 520 ) secured to said second gear wheel ( 52 ), said second roller ( 520 ) having diameter substantially equal to the pitch circle diameter of said second gear wheel ( 52 ), said second roller ( 520 ) abutting on said second rolling surface ( 720 ), wherein the displacement of the control racks changes the compression ratio and the two-sided piston rack structure substantially reduces the forces that load the rollers.