A two-stroke internal combustion engine includes:—a base;—a head, fixed to the base, and having a cylindrical cavity;—a piston slidable in the cylindrical cavity, to define a combustion chamber and a pumping chamber, and movable in the cylindrical cavity between a bottom and a top dead center;—a transfer duct having an inlet mouth in fluid communication with the pumping chamber, and an outlet mouth in fluid communication with the combustion chamber;—an exhaust duct having an inlet mouth in fluid communication with the combustion chamber,—a crank shaft partially housed in the pumping chamber;—a connecting rod connecting the piston to the crank shaft;—a movable partition housed inside the pumping chamber operatively connected to the crank shaft to occlude the transfer duct inlet mouth and to put in fluid communication the transfer duct inlet mouth with the pumping chamber.

Disclosed is a combustion engine and method for engine braking therein including an intake air channel having a first pressure, a first inlet valve between the intake air channel and the cylinder volume, an exhaust air channel having a second pressure, a first outlet valve between the cylinder volume and the exhaust air channel, and a storage reservoir having a third pressure higher than the first and second pressures, the storage reservoir being arranged in controllable fluid communication with the cylinder volume. The method takes place during two-stroke cycle and includes: displacing the piston from upper dead centre (UDC) towards lower dead centre (LDC), keeping the first inlet valve open during at least part of the travel from UDC to LDC, displacing the piston from LDC towards UDC, and keeping the fluid communication between the storage reservoir and cylinder volume open during at least a part of such travel.

A four cylinder engine including two outer cylinders valved to operate on a four cycle basis, the outer two cylinders being movable together in opposite directions than the direction of movement together of the two inner cylinders. The two inner cylinders valved to operate on a two-cycle basis. The four cylinders having fuel injectors for injecting an amount of fuel in an associated cylinder so as to cause a self-ignited power event to occur therein during each cycle. The engine, when embodied in a vehicle having a battery energized computer and manually operated accelerator pedal being selectively operated in three power levels: (1) a minimum fuel mode (2) an intermediate fuel mode and (3) a maximum fuel mode. (1) Enabling a two-third fuel saving (two injections out of a possible six) when in minimum fuel mode and (2) a one-third saving fuel (four injections out of a possible six) when in the intermediate mode. The two inner cylinders operate on the fuel sharing principles of the '769 patent when in the intermediate mode.

A closing fork and open spring bias of a center power valve for a hitless control of an adjustable exhaust port 2-stroke motorcycle engine includes a closing fork which includes a flat plate that extends into two substantially parallel flat closing fork arms. An internal closing fork base section cylindrical wall accepts a shaft inserted there through. Each torsion spring of two torsion springs has a first extended leg including an approximately 90-degree bend about where the first extended leg extends out from a spring body of each torsion spring and a second leg extending straight out of a body of each torsion spring. Each of the torsion springs is a mirror of each other where the first extended leg extends from a different side. An upgrade kit and a method to convert a power valve system 2-stroke motorcycle engine to a hitless operation are also described.

The present invention concerns a mechanism (1), comprising: one support (2) including a base (3), one pendulum (4), and connecting suspension rods (5) articulated on the base (3) and on the pendulum (4); two mobile cog wheels (12; 22) in rotation around their respective axis (A1; A2); two eccentric elements (14; 24) integral with the cog wheels (12; 22) in rotation and generating moments of gravity force around their axis (A1; A2); and one connecting link rod (60; 160) comprising a rotary head (62) and an eccentric head (63). The axis (A1; A2) are parallel within a horizontal or vertical reference plane (P0). The pendulum (4) supports the axis (A1; A2) of the cog wheels (12; 22) and of the eccentric elements (14; 24). The connecting rods (5) are slanting in accordance with an angle comprised between 45 degrees and 80 degrees in relation to a vertical plane. The cog wheels (12; 22) engage one with the other using a unitary transmission ratio and are mobile in rotation in opposing directions. When the mechanism (1) is in operation, the eccentric elements (14; 24) follow an elliptical movement, whereas the pendulum (4) follows a travel movement having a vertical component and a horizontal component. The moments of gravity force of the eccentric elements (14; 24) have a same value and a same direction, both being variable depending on their angular position around the axis (A1; A2). For each angular position of the cog wheels (12; 22) and of the eccentric elements (14; 24) around the axis (A1; A2), the mechanism (1) presents an equilibrium configuration at rest.

An actuation system for a valve is disclosed. The actuation system comprises a housing having an end wall. A first piston and a second piston is slidably positioned within the housing. The second piston is positioned between the first piston and the end wall. A piston rod is coupled to the first piston and slidably extends through the second piston and the end wall. The piston rod is configured to be coupled with the valve. A first spring is arranged between the first piston and the second piston. Further, a second spring is arranged between the second piston and the end wall. The first spring and the second spring are configured to bias the valve to a closed position.

With reference to FIG. 2, the invention relates to an opposed stepped piston two-stroke engine comprising at least a first and a second cylinder, wherein the air piston is a stepped piston providing a first air transfer piston that expands and compresses a first air transfer volume to deliver air from the first air transfer volume to an air transfer system, and the exhaust piston is a stepped piston providing a second air transfer piston that expands and compresses a second air transfer volume to deliver air from the second air transfer volume to the air transfer system, each of the first and second air transfer volumes having an air inlet for receiving air; and wherein the air transfer system provides fluid connection between the respective first air transfer volume of each cylinder and the air port of another respective cylinder, via respective first air transfer conduits, and fluid connection between the respective second air transfer volume of each cylinder and the air port of the other respective cylinder, via respective second air transfer conduits, wherein the drive system is configured, for each cylinder, to have a predetermined phase angle such that one of the exhaust piston and air piston is driven before the other piston, causing delivery of air from its respective air transfer volume to the air transfer system before delivery of air occurs from the other of the air transfer volumes.

A two-stroke engine comprises a first oiling system and a second oiling system. The first oiling system includes a low-pressure pump that distributes oil from a first oil tank to the two-stroke engine. The second oiling system includes a pump mechanically coupled to a crankshaft of the two-stroke engine, wherein the pump distributes oil from a second oil tank to an accessory at a pressure greater than the first oil pressure, wherein oil distributed to the accessory is returned to the second oil tank.

A uniflow scavenging 2-cycle engine includes a cylinder inside which a combustion chamber is formed; a piston which slides within the cylinder; a scavenge port which is provided on one end side in a stroke direction of the piston in the cylinder to suck an active gas into the combustion chamber in accordance with the sliding movement of the piston; and a fuel injection unit which has an injection port located on the outside of the cylinder, and injects the fuel gas into the active gas sucked into the scavenge port.

A method which develops a supercritical combustion chamber environment and combines fumigation and water conversion to superheated steam to effect greater fuel efficiency and reduce exhaust gas pollutants from a compression ignition engine. The invention utilizes the fumigant method by combining two gases (DME and heptane) which autoignite prior to the injection of the liquid water. This pre-combustion of the fumigant gases combined with the engine's compression of the combustion chamber gases is managed to attain a supercritical combustion chamber environment into which the liquid water is injected. This targeted supercritical combustion chamber environment causes the water to become a superheated steam, resulting in significantly greater efficiency and negligible exhaust gas pollutants resulting from the steam engine.