There is provided an internal combustion engine, provided with a crankshaft and one or several cylinders provided on the wall thereof with exhaust ports and closed at the top by a cylinder head provided with intake ports; each cylinder accommodating an engine piston connected to the crankshaft and a coaxial auxiliary piston opposite the engine piston, defining an intake chamber and a combustion chamber; said auxiliary piston axially determining on the side of the combustion chamber a housing that communicates with the intake chamber via transfer ports, the housing of which includes a secondary piston which opens and closes the transfer ports in a back-and-forth movement between a rear position and a forward position.

A cam and follower apparatus adapted to translate the force of a piston to turn the shaft of an engine. The cam profile is made of three intersecting circles allowing for one follower to be near top dead center while another follower is near bottom dead center. The surface of the follower is a circle which shares the same center point and radius with the circles of the cam profile. The surface of the follower also closely intersects the axis of the follower preventing the follower from spinning like a roller follower. The follower can therefore spread the force from the piston to a wider area on the cam for longevity.

A six-stroke engine includes a cylinder, a piston, a cylinder head, a combustion chamber, an intake port, an exhaust port, an intake valve, an exhaust valve, a fuel injector, and an ignition plug. The six-stroke engine includes a valve gear that operates the intake valve and the exhaust valve to execute an intake stroke, a compression stroke with ignition, an expansion stroke with combustion, an exhaust stroke, an expansion stroke without combustion, and a compression stroke without ignition. The valve gear opens, only for a predetermined period of time while the piston is located at top dead center, at least one of the intake valve and the exhaust valve within a period from the exhaust stroke to the intake stroke. A valve overlap state is produced at least once within the period from the exhaust stroke to the intake stroke.

A six-stroke engine includes a cylinder, a piston, a cylinder head, a combustion chamber, an intake port, an exhaust port, an intake valve, an exhaust valve, a fuel injector, and an ignition plug. The six-stroke engine includes a valve gear that operates the intake valve and the exhaust valve to execute an intake stroke, a compression stroke with ignition, an expansion stroke with combustion, an exhaust stroke, an expansion stroke without combustion, and a compression stroke without ignition. The valve gear opens, only for a predetermined period of time while the piston is located at top dead center, at least one of the intake valve and the exhaust valve within a period from the exhaust stroke to the intake stroke. A valve overlap state is produced at least once within the period from the exhaust stroke to the intake stroke.

A valve train assembly configured to selectively open and close intake and exhaust valves associated with cylinders of an internal combustion engine comprises an intake rocker arm assembly, an intake cam assembly, a first axial shifting cam assembly and a second axial shifting cam assembly. The intake rocker arm assembly can have a plurality of intake rocker arms. The intake cam assembly can be associated with each of the cylinders and can have three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile. The first axial shifting cam assembly can operate independently from the second axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

An internal combustion engine comprising at least one pair of opposed, reciprocating pistons forming a combustion chamber therebetween a crankshaft driven by the pistons via respective drive linkages. The outer piston furthest from the crankshaft comprises a skirt extending from its perimeter towards the crankshaft to form a cylinder within which the other, inner piston reciprocates.

An internal combustion engine comprising at least one pair of opposed, reciprocating pistons forming a combustion chamber therebetween a crankshaft driven by the pistons via respective drive linkages. The outer piston furthest from the crankshaft comprises a skirt extending from its perimeter towards the crankshaft to form a cylinder within which the other, inner piston reciprocates.

An engine compression brake device is disclosed. The brake device has at least one camshaft which has at least one cam group with at least one firing cam and at least one brake cam, and has at least one cam follower which is functionally assigned to the firing cam and which is provided for actuating at least one gas exchange valve in a firing mode, and has a cam follower which is functionally assigned to the brake cam and which is provided for actuating at least one gas exchange valve in a braking mode. The brake device further has a switchover device which is provided for the switchover between the firing mode and the braking mode, where the switchover device is provided for converting a torque of the camshaft into a force for the switchover between the firing mode and the braking mode.

An engine compression brake device is disclosed. The brake device has at least one camshaft which has at least one cam group with at least one firing cam and at least one brake cam, and has at least one cam follower which is functionally assigned to the firing cam and which is provided for actuating at least one gas exchange valve in a firing mode, and has a cam follower which is functionally assigned to the brake cam and which is provided for actuating at least one gas exchange valve in a braking mode. The brake device further has a switchover device which is provided for the switchover between the firing mode and the braking mode, where the switchover device is provided for converting a torque of the camshaft into a force for the switchover between the firing mode and the braking mode.

An internal-combustion engine has a plurality of cylinders each with two intake valves driven by respective pumping pistons operatively associated to cams of a camshaft, by respective hydraulic circuits. The hydraulic has its pressure chamber communicating with hydraulic actuators of the two intake valves, so that the two intake valves of each cylinder are controlled, via two different hydraulic circuits, by cams associated to two different cylinders. Each cam is configured to give rise to a cycle of opening and closing of each of the intake valves in an angular range of rotation of the crankshaft less than 180 such that, in each operating cycle of a cylinder, only the first intake valve initially opens and closes while the second intake valve remains closed, and then the second intake valve opens and closes while the first intake valve remains closed.