Patent ID: 6655340
Filing Date: 2003-12-02
Classification: F02B

Abstract:
An engine comprising:a frame mounting a crankshaft and reciprocating components in inline cylinders that together produce a second order pitching couple acting on the engine frame; and a balancer mounted to the engine for balancing the pitching couple when the engine is operating, the balancer including: a drive sprocket carried by the crankshaft for rotation therewith; a drive chain engaging the drive sprocket; first and second driven sprockets engaged by the drive chain; a first balance shaft mounted to one side of the engine frame and directly connected with the first sprocket for angular rotation in the direction of the crankshaft at twice crankshaft speed; a second balance shaft mounted to an opposite side of the engine frame and indirectly connected to the second sprocket through a reversing drive for angular rotation opposite the direction of the crankshaft at twice crankshaft speed; said balance shafts each having longitudinally-spaced, oppositely phased balance weights, the shafts developing equal oppositely rotating unbalance couples that combine to generate a vertical pitching couple equal to and balancing the second order pitching couple of the engine.