An engine and gear train combination is provided which includes an engine which drives a first crankshaft having a first gear disposed thereon; a second crankshaft having a second gear and a flywheel disposed thereon, wherein the second gear meshes with the first gear; and a pulse compensator having a central element which is pivotally connected on a first end thereof to a first set of lateral members and which is pivotally connected on a second end thereof to a second set of lateral elements. Each element of the first set of lateral elements is also pivotally connected to the second crankshaft, and each element of the second set of lateral elements is pivotally connected to a mount.

A power unit for a hybrid vehicle is provided with a twin-cylinder reciprocating piston engine, which has two pistons which are guided in two cylinders in tandem arrangement. Two counter-directional crankshafts are connected with the pistons by connecting rods. At least one generator is rotatable co-directionally to the first crankshaft and counter-directionally to the second crankshaft. A camshaft with valve cams are operatively connected with control valves. A flywheel mass element is arranged on the second crankshaft or on a flywheel mass compensating shaft, and a compensating camshaft are provided. The compensating camshaft includes at least one compensating cam element which is operatively connected with a linearly guided compensating mass.

The outboard motor of the reciprocating piston internal combustion engine type has a crankshaft system with a crankshaft positioned upright within a machine housing of the internal combustion engine and having at an upper end region a flywheel. The flywheel is clad with a cover that extensively surrounds the flywheel starting at a top side of the internal combustion engine. Here, the crankshaft system has two parallel crankshafts that are each provided at their upper end regions with flywheels. The flywheels, when viewed in the axial direction of the crankshafts, are arranged offset with respect to each other and overlap in the manner of circular segments. The cover encapsulates the two flywheels over a significant range and is held in position on pivot axles of the flywheels.

A moment-cancelling, four-stroke engine is disclosed. The engine includes a first cylinder having a first piston and a second cylinder having a second piston, a first crankshaft operably connected to the first piston and a second crankshaft operably connected to the second piston. The first crankshaft rotates in a first direction and the second crankshaft rotates in a second direction that is opposite the first direction to cancel the moments applied to the engine and reduce engine vibration.

An internal combustion engine has a uniblock that defines a blind cylinder bore that terminates within the uniblock. A piston is inserted into the cylinder bore from a bottom end of the cylinder bore. Parallel first and second vertical planes extend along first and second lateral sides of the cylinder bore. A cylinder zone being defined between the first and second vertical planes. A crosshead is coupled to the piston. A first crankshaft has a first crankshaft axis that extends parallel to the first vertical plane and that is positioned outside of the cylinder zone. A second crankshaft has a second crankshaft axis that extends parallel to the second vertical plane and that is positioned outside of the cylinder zone. The first crankshaft is coupled to the crosshead with a first connecting rod and the second crankshaft is coupled to the crosshead with a second connecting rod.