A reciprocating exhaust valve for a two-stroke internal combustion engine has a shaft for connection to a valve actuator, the shaft defining a reciprocation axis of the valve, the reciprocation axis defining a longitudinal direction of the valve; and a blade having: a first end having an arcuate edge, a second end connected to the shaft, two side portions, and a central portion. The blade has a first end portion adjacent the first end that includes a part of the central portion and of each of the two side portions. A width of the central portion is greater than a width of each of the side portions. In the first end portion, a thickness of the part of each of the two side portions is greater than a thickness of the part of the central portion.

An exhaust valve system for a two-stroke internal combustion engine having: at least one exhaust valve movable between open and closed positions; an actuator for moving the at least one exhaust valve; a valve position sensor; a controller communicating with the actuator and the valve position sensor. The controller being programmed for: controlling the actuator to attempt to move the at least one exhaust valve to a desired one of the open and closed positions; determining if the at least one exhaust valve has failed to reach the desired position based on the position of the at least one exhaust valve sensed by the valve position sensor; and controlling the actuator to move the at least one exhaust valve to an intermediate position when the at least one exhaust valve has failed to reach the desired position.

An exhaust valve assembly for a two-stroke internal combustion engine has a housing adapted for connection to an engine block of the two-stroke internal combustion engine; an electric actuator having an electric motor, the electric motor being disposed in the housing; and at least one reciprocating exhaust valve operatively connected to the electric actuator. The at least one exhaust valve is linearly movable by the electric motor. A portion of the at least one exhaust valve is disposed in the housing.

A combustion engine is provided having combustion chambers with reciprocating pistons, intake ports and exhaust ports. Transfer ports may be provided between adjacent combustion chambers to provide a transfer channel that closes during a high load mode of operation of the engine and opens during a partial load mode of operation. Also provided are embodiments in which exhaust ports of adjacent combustion chambers are joined into a common exhaust channel that communicates with an exhaust header of the engine through valve means that open during the high load mode of operation of said engine and close during a partial load mode of operation.

A pivoting flap valve is provided for an internal combustion rotary that produces mechanical torque. The engine includes an annular planar housing with a substantially circular annulus flanked by first and second cavities, an axial shaft, a rotor disposed on the shaft and rotating within the annulus. The valve is disposed within one cavity of said cavities and includes an arc wedge and a pivot shaft. The wedge has outer convex surface and an inner concave surface and a shaft hole between and parallel to the surfaces along a rocking axis. The pivot shaft passes through the shaft hole that enables the wedge to rock back and forth within the cavity in the annular planar housing without interference with the cam block. Each valve includes indents to pass around fore and aft circular wings on a rotor. The engine includes the housing, the rotor, first and second sparkplugs, first and second flap valves, an axial shaft and fore-and-aft covers. The housing includes a quadrilateral symmetry including a substantially circular annulus flanked by first and second cavities. The wings of the rotor intermittently block at least one port while the axial shaft rotates.

A cam phasing mechanism (1) for a cam assembly (100) of an internal combustion engine, the cam assembly (100) comprising a camshaft (120) and an actuator (130) for opening a valve (505) at a reference position of rotation of the camshaft (120), the cam phasing mechanism (1) comprising: a force transfer member (2a) for interposition between the camshaft (120) and the actuator (130) of the cam assembly (100) for transferring force between the camshaft (120) and the actuator (130); and an adjuster (2b) for selectively moving the force transfer member (2a) to adjust the reference position of rotation of the camshaft (120).

An internal combustion rotary engine is provided for producing mechanical torque. The engine includes an annular planar housing, a rotor, sparkplugs, flap valves, an axial shaft and fore-and-aft covers. The housing includes a quadrilateral symmetry including a substantially circular annulus flanked by first and second cavities. The rotor has a cam block sandwiched between fore and aft circular wings. The sparkplugs are respectively accessible to the second cavities. The flap valves rock within the respective cavities and within the cam block. Each valve includes indents to pass around the wings. The fuel intake provides fuel to the cavities. The axial shaft rotates the rotor within the housing. Covers, each having a center orifice and a pair of ports exposed to ambient and respectively adjacent the first and second cavities. The wings intermittently block at least one port while the rotor rotates.

A turbocharger for an engine includes a housing, a shaft, a turbine wheel mounted to the shaft for rotation therewith, a compressor wheel mounted to the shaft for rotation therewith, and a bearing cartridge rotatably supporting the shaft relative to the housing. The housing is positioned axially between the turbine and compressor wheels. The bearing cartridge includes an inner ring mounted to the shaft, an outer ring disposed between the inner ring and the housing and movable relative to the housing, and a first and a second plurality of roller elements axially spaced apart from one another and disposed radially between the inner and outer rings to rotatably support the inner ring relative to the outer ring. A radial gap (RD) is defined between the outer ring (134) and the housing (126). Lubricant flows into the radial gap and radially separates the outer ring from the housing during operation of the turbocharger.

The present invention concerns a method and a device for electrically controlling a valve actuator in a two-stroke or four-stroke combustion engine where the actuator comprises a solenoid (A), a plunger (5) and a spring (6), wherein the engine has at least one cylinder (1) with at least one freely controllable engine valve disc (10) with corresponding valve stem (11) and a valve spring (4), where a distance (7) is provided between the lower end of the plunger and the upper end of the valve stem and where air is supplied, or exhaust gases are evacuated from, a combustion chamber (3) past a lower part of the valve stem with the valve disc via at least one channel (2) in the cylinder, wherein the valve actuator is activatable to open the engine valve. The invention is characterized in that the opening of the engine valve is initiated after activation of the solenoid, wherein the following acceleration of the plunger brings its lower end to strike the upper end of the valve stem for initial opening of the valve.

The present invention concerns a method and a device for electrically controlling a valve actuator in a two-stroke or four-stroke combustion engine where the actuator comprises a solenoid (A), a plunger (5) and a spring (6), wherein the engine has at least one cylinder (1) with at least one freely controllable engine valve disc (10) with corresponding valve stem (11) and a valve spring (4), where a distance (7) is provided between the lower end of the plunger and the upper end of the valve stem and where air is supplied, or exhaust gases are evacuated from, a combustion chamber (3) past a lower part of the valve stem with the valve disc via at least one channel (2) in the cylinder, wherein the valve actuator is activatable to open the engine valve. The invention is characterized in that the opening of the engine valve is initiated after activation of the solenoid, wherein the following acceleration of the plunger brings its lower end to strike the upper end of the valve stem for initial opening of the valve.