An internal combustion engine, including a piston, a cylinder, and an output shaft, wherein the piston is arranged for reciprocating motion within the cylinder, driven by combustion, and the piston is coupled to the output shaft by a coupling such that said reciprocating motion of the piston drives rotation of the output shaft, wherein the coupling includes a connecting rod coupled to the piston, a slider bearing located for reciprocating movement relative to the connecting rod, the coupling further including a crankshaft rotatably mounted within a slider bearing, the engine having a camshaft and a balance shaft wherein the balance shaft is housed in a hollow of the camshaft such that the camshaft and the balance shaft rotate about a common axis.

A crank mechanism for the use in an in-line boxer engine has at least two diametrically opposed cylinders, that has a crankshaft and the respective pistons as well as connecting rods for each cylinder of the in-line boxer engine, with the connecting rods cooperatively connecting the pistons with the crankshaft. Each of the connecting rods encompasses a respective piston connecting portion, at one end having bushings accepting a gudgeon pin. At the other end, the central connecting rod has a one-piece crankshaft bearing portion for the crankpin whereas the forked connecting rod has a crankshaft bearing portion with two spaced limbs resultant in bifurcated crankshaft bearing portions for the crankpin. The crankshaft possesses a cylindrical central middle crankpin, that is eccentric towards the crankshaft, onto which a cylindrical outer crank pin is immediately attached at each side without crank webs.

A UAV propulsion system is disclosed that utilizes a crankcase having a first crankcase compartment and a second crankcase compartment. Each crankcase compartment includes a corresponding cylinder assembly and piston, with each piston being interconnected with a rotatable crankshaft. A first airflow path extends from an exterior of the UAV propulsion system to the first crankcase compartment, and a separate second airflow path extends from the exterior of the UAV propulsion system to the second crankcase compartment. A first rotary valve may be mounted on and rotate with the crankshaft to control the airflow along the first airflow path to the first crankcase compartment, while a second rotary valve may be mounted on and rotate with the crankshaft to control the airflow along the second airflow path to the second crankcase compartment.

A ferritic aero diesel engine. The ferritic aero diesel engine includes an iron crankcase, a steel crankshaft and eight steel piston assemblies. The iron crankcase has a flat, horizontally opposed eight cylinder arrangement with a first set of cylinder walls defining a first set of cylinders in a first bank and a second set of cylinder walls defining a second set of cylinders in an opposed second bank. The steel crankshaft is rotatably mounted at least partially within the iron crankcase. Each of the steel piston assemblies of the plurality of steel piston assemblies is received within a respective cylinder of the iron crankcase and is coupled to the steel crankshaft. The first and second sets of cylinder walls have a minimum wall thickness of between approximately 4.8 and 5.2 mm.

An internal combustion engine includes a crankcase that defines a crank chamber, a crankshaft that has a crank housed in the crank chamber and is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a horizontally-opposed arrangement, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that extends through the crankcase from an upper face of the crankcase, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thus, in a so-called horizontally-opposed internal combustion engine, a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision is provided.

A mixture-lubricated four stroke engine has a cylinder in which a combustion chamber is formed. The combustion chamber is delimited by a piston which is mounted movably in the cylinder. The engine has an intake channel which discharges into the combustion chamber via an inlet opening controlled by an inlet valve. A mixture formation unit includes at least one fuel opening which discharges into the intake channel. For the lubrication of the crankcase interior, a flow connection connects the intake channel to the crankcase interior via a connecting opening which discharges into the intake channel downstream of the mixture formation unit. The fuel quantity is controlled by a fuel valve. A control unit is configured to activate the fuel valve in a manner dependent on the position of the crankshaft such that the fuel valve is opened at least also during a part of the compression stroke.

It is disclosed a boxer engine with two substantially mirror-symmetric engine sides (L, R) comprising a crankshaft (1) to which is connected, at least two main scotch yoke assemblies (110) each having one main piston (7) arranged inside one main cylinder (I, III; II, IV) of each engine side (R; L), and at least one auxiliary scotch yoke assembly (120) having a pair of auxiliary pistons (8) arranged inside a pair of auxiliary cylinders (V, VII; VI, VIII) of each engine side (R; L), wherein the main scotch yoke assemblies (110) are arranged synchronized on the crankshaft (1) and the at least one auxiliary scotch yoke assembly (120) is arranged 180° offset on the crankshaft (1), each auxiliary piston (7) defining an outer space and an inner space within each auxiliary cylinder (V, VII; VI, VIII), the inner space facing the opposite engine side (R; L), wherein, said inner spaces of each auxiliary cylinder (V, VII; VI, VIII) pair are in fluid communication and forming a compression chamber, said compression chamber comprises first and second check valves (69, 70), wherein the auxiliary cylinder (V, VII; VI, VIII) pair is adapted to suck in ambient air through the first check valve (69) and compress and pump said air out through the second check valve (70) into a main cylinder (I, III; II, IV) of the opposite engine side (R; L), and said outer spaces of each auxiliary cylinder (V, VII; VI, VIII) pair are in fluid communication and are receiving pressurized exhaust gas from a main cylinder (I, III; II, IV) of the same engine side (R; L).

It is disclosed a boxer engine with two substantially mirror-symmetric engine sides (L, R) comprising a crankshaft (1) to which is connected, at least two main scotch yoke assemblies (110) each having one main piston (7) arranged inside one main cylinder (I, III; II, IV) of each engine side (R; L), and at least one auxiliary scotch yoke assembly (120) having a pair of auxiliary pistons (8) arranged inside a pair of auxiliary cylinders (V, VII; VI, VIII) of each engine side (R; L), wherein the main scotch yoke assemblies (110) are arranged synchronized on the crankshaft (1) and the at least one auxiliary scotch yoke assembly (120) is arranged 180° offset on the crankshaft (1), each auxiliary piston (7) defining an outer space and an inner space within each auxiliary cylinder (V, VII; VI, VIII), the inner space facing the opposite engine side (R; L), wherein, said inner spaces of each auxiliary cylinder (V, VII; VI, VIII) pair are in fluid communication and forming a compression chamber, said compression chamber comprises first and second check valves (69, 70), wherein the auxiliary cylinder (V, VII; VI, VIII) pair is adapted to suck in ambient air through the first check valve (69) and compress and pump said air out through the second check valve (70) into a main cylinder (I, III; II, IV) of the opposite engine side (R; L), and said outer spaces of each auxiliary cylinder (V, VII; VI, VIII) pair are in fluid communication and are receiving pressurized exhaust gas from a main cylinder (I, III; II, IV) of the same engine side (R; L).

An internal combustion engine includes a crankcase that defines a crank chamber, a crankshaft that has a crank housed in the crank chamber and is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a horizontally-opposed arrangement, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that extends through the crankcase from an upper face of the crankcase, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thus, in a so-called horizontally-opposed internal combustion engine, a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision is provided.

A mixture-lubricated four stroke engine has a cylinder in which a combustion chamber is formed. The combustion chamber is delimited by a piston which is mounted movably in the cylinder. The engine has an intake channel which discharges into the combustion chamber via an inlet opening controlled by an inlet valve. A mixture formation unit includes at least one fuel opening which discharges into the intake channel. For the lubrication of the crankcase interior, a flow connection connects the intake channel to the crankcase interior via a connecting opening which discharges into the intake channel downstream of the mixture formation unit. The fuel quantity is controlled by a fuel valve. A control unit is configured to activate the fuel valve in a manner dependent on the position of the crankshaft such that the fuel valve is opened at least also during a part of the compression stroke.