Patent ID: 8413619
Filing Date: 2013-04-09
Classification: F01B,F01L,F02B,F02D

Abstract:
1. A method for varying the compression ratio in an engine having a first piston that cooperates with a second piston to define a combustion chamber therebetween, the method comprising: moving the first piston back and forth in a first cycle between a first bottom dead center (BDC) position and a first top dead center (TDC) position according to a first piston timing; moving the second piston back and forth in a second cycle between a second BDC position and a second top dead center TDC position according to a second piston timing; while moving the first piston according to the first piston timing and the second piston according to the second piston timing, periodically opening and closing at least one passage in fluid communication with the combustion chamber according to a valve timing; and while maintaining the valve timing, varying the compression ratio of the combustion chamber by— changing the first piston timing relative to the valve timing; and changing the second piston timing relative to the valve timing.