A two-stroke engine includes a crankcase. A power cylinder extends from the crankcase. The power cylinder selectively fluidly communicates with the crankcase to scavenge the power cylinder. A power piston is reciprocably disposed in the power cylinder. A compressor cylinder extends from the crankcase. The compressor cylinder selectively fluidly communicates with the power cylinder to introduce a pressurized air/fuel mixture into the power cylinder. A compressor piston is reciprocably disposed in the compressor cylinder.

A crankshaft having a balance weight, the crankshaft a crank pin eccentric to a rotation axis of the crankshaft, a connecting rod connecting the crank pin and a piston, and a balance weight disposed to be opposite to the crank pin in the crankshaft, wherein the balance weight has radius which is a distance between the rotation axis of a crankshaft and an exterior circumferential surface of the balance weight, and wherein the radius of the balance weight is formed differently depending on a rotation direction of the balance weight.

An internal combustion engine including a first set of cylinders includes: a first two-stroke compression cylinder housing a first compression piston connected to a first crank shaft; a first four-stroke combustion cylinder housing a first combustion piston connected to a second crank shaft, the first four-stroke combustion cylinder being configured to receive compressed gas from the first two-stroke compression cylinder; and a first two-stroke expansion cylinder housing a first expansion piston connected to the first crank shaft, the first two-stroke expansion cylinder being configured to receive exhaust gas from the first four-stroke combustion cylinder, wherein the first compression piston is positioned to reach a lower end position within the first compression cylinder and the first expansion piston is positioned to reach an upper end position within the first expansion cylinder when the first combustion piston reaches a lower end position within the first combustion cylinder; wherein the second crank shaft is configured to rotate with a speed of at least twice the speed of the first crank shaft.

An engine and corresponding driving propulsion system may provide continuous force necessary to keep the engine operating. Utilizing two pressurized tanks with high and low pressures may provide a continuous flow of pressure to the engine necessary for it to operate.

Vibration generated by a secondary inertia couple caused by lateral pressures from pistons of a V-shaped engine is reduced. A cylinder axis of a first cylinder and a cylinder axis of a second cylinder define a splay angle in a range of about 45 to about 75. First and second crankpins have a phase difference in a circumferential direction of a shaft center of a crankshaft in a range of about 30 to about 90. A balancer shaft included in a single-shaft balancer mechanism rotates in a direction opposite to that in which the crankshaft rotates at a speed twice that at which the crankshaft rotates. As viewed in an axial direction of the crankshaft, the balancer shaft is located on a side of a second reference line which is opposite to a side including first and second pistons, the second reference line being perpendicular or substantially perpendicular to a first reference line and passing through the shaft center of the crankshaft, the first reference line passing through the shaft center of the crankshaft and dividing the splay angle into two equal sub-angles.

Vibration generated by a secondary inertia couple caused by lateral pressures from pistons of a V-shaped engine is reduced. A cylinder axis of a first cylinder and a cylinder axis of a second cylinder define a splay angle in a range of about 45 to about 75. First and second crankpins have a phase difference in a circumferential direction of a shaft center of a crankshaft in a range of about 30 to about 90. A balancer shaft included in a single-shaft balancer mechanism rotates in a direction opposite to that in which the crankshaft rotates at a speed twice that at which the crankshaft rotates. As viewed in an axial direction of the crankshaft, the balancer shaft is located on a side of a second reference line which is opposite to a side including first and second pistons, the second reference line being perpendicular or substantially perpendicular to a first reference line and passing through the shaft center of the crankshaft, the first reference line passing through the shaft center of the crankshaft and dividing the splay angle into two equal sub-angles.

An internal combustion engine according to the invention comprises at least two engine blocks which are coupled to one another and each of which includes at least two cylinders, each cylinder being connected to a common drive shaft via a transmission and a clutch. If there is a problem with one engine block, same can be disconnected from the drive shaft so that the engine can continue to operate by means of the other engine block.

An internal combustion engine according to the invention comprises at least two engine blocks which are coupled to one another and each of which includes at least two cylinders, each cylinder being connected to a common drive shaft via a transmission and a clutch. If there is a problem with one engine block, same can be disconnected from the drive shaft so that the engine can continue to operate by means of the other engine block.

A crankshaft having a balance weight, the crankshaft a crank pin eccentric to a rotation axis of the crankshaft, a connecting rod connecting the crank pin and a piston, and a balance weight disposed to be opposite to the crank pin in the crankshaft, wherein the balance weight has radius which is a distance between the rotation axis of a crankshaft and an exterior circumferential surface of the balance weight, and wherein the radius of the balance weight is formed differently depending on a rotation direction of the balance weight.

Vibration generated by a secondary inertia couple caused by lateral pressures from pistons of a V-shaped engine is reduced. A cylinder axis of a first cylinder and a cylinder axis of a second cylinder define a splay angle in a range of about 45 to about 75. First and second crankpins have a phase difference in a circumferential direction of a shaft center of a crankshaft in a range of about 30 to about 90. A balancer shaft included in a single-shaft balancer mechanism rotates in a direction opposite to that in which the crankshaft rotates at a speed twice that at which the crankshaft rotates. As viewed in an axial direction of the crankshaft, the balancer shaft is located on a side of a second reference line which is opposite to a side including first and second pistons, the second reference line being perpendicular or substantially perpendicular to a first reference line and passing through the shaft center of the crankshaft, the first reference line passing through the shaft center of the crankshaft and dividing the splay angle into two equal sub-angles.