Patent ID: 9103396
Filing Date: 2015-08-11
Classification: F16F

Abstract:
1. A parallel twin cylinder internal combustion engine comprising: a balancer device disposed inside the parallel twin cylinder internal combustion engine; a common crankshaft having a first crankpin and a second crankpin disposed at a predetermined phase angle; and a cylinder block having a first cylinder corresponding to the first crankpin and a second cylinder corresponding to the second crankpin, wherein the balancer device is configured to reduce a first cylinder vibratory force and a second cylinder vibratory force which are generated when the crankshaft is rotated in the parallel twin cylinder internal combustion engine, wherein the first cylinder vibratory force generates force directed outward in a radial direction of the crankshaft while performing inverse rotation with the same period as the crankshaft based on a position where a first piston stored in the first cylinder is at a top dead center, wherein the second cylinder vibratory force generates force directed outward in the radial direction of the crankshaft while performing the inverse rotation with the same period as the crankshaft based on a position where a second piston stored in the second cylinder is at the top dead center, wherein when viewed in an axial direction of the crankshaft, a straight line for bisecting an angle formed between the first cylinder vibratory force and the second cylinder vibratory force is defined as an angle bisector, wherein the force with the first cylinder vibratory force and the force with the second cylinder vibratory force are resolved into an inertial force component resolved into a direction parallel to the angle bisector, and resolved into a couple component resolved into a direction parallel to a plane perpendicular to the angle bisector, wherein the balancer device comprises an inertial force balancer that is configured to generate force facing the inertial force component, and wherein the balancer device comprises a couple balancer that is configured to generate force facing the couple component.