Abstract: A multicylinder internal combustion free-piston engine (FPE) with synchronized reciprocating plungers. The invention provides a solution for the problem of the slow engine speed typical of FPE's with heavy plunger mass. Bounce chambers fitted with sleeve valves control the engine's speed and stroke length. The invention's configuration prevents piston head-strikes and operates at standard compression ratios. Piston “pop-top” intake valves allow uniflow scavenging and connecting rod oil channels provide lubrication with no combustion chamber contamination. Poppet combustion head valves are operated by linear cams attached to the plungers. Hydraulic valve actuators implement variable valve timing under computer control.

Abstract: A two-cycle internal combustion engine with rear compression chamber, other than that of a crank case. This present engine has valves that can be screwed on the engine block near top dead center, and is actuated by air pressure. This present two-cycle engine uses an oil sump similar to that of a four-cycle engine, which eliminates the need to premix oil with the fuel. This present engine has a stationary piston which operates within a movable piston to form a rear-compression chamber. The movable piston has ports near its crown to transfer charge to the combustion chamber. The movable piston also has ports near bottom of its skirt to allow the fuel and air mixture to enter the rear compression chamber. This engine has a piston seat which is adapted to connect the movable piston to the connecting rod.

Abstract: A rocking journal bearing is provided in a piston coupling mechanism. The bearing includes a sleeve and a wristpin constructed with two sets of eccentrically-disposed bearing surfaces which alternate in accepting a compressive load during an operational cycle of the bearing. The sleeve includes a network of grooves to transport oil to the bearing surfaces. Lubricating oil flow through the bearing is minimized by limiting provision of pressurized oil from the wristpin to the network of grooves to portions of the cycle when one or the other of the sets of bearing surfaces receives the compressive load.

Abstract: A rocking journal bearing is provided in a piston coupling mechanism. The bearing includes a sleeve and a wristpin constructed with two sets of eccentrically-disposed bearing surfaces which alternate in accepting a compressive load during an operational cycle of the bearing. The sleeve includes a network of grooves to transport oil to the bearing surfaces. Lubricating oil flow through the bearing is minimized by limiting provision of pressurized oil from the wristpin to the network of grooves to portions of the cycle when one or the other of the sets of bearing surfaces receives the compressive load.

Abstract: A method of constructing a piston, piston formed thereby, and piston body portions are provided. The method includes providing an upper crown portion at least one annular upper rib depending from the upper combustion wall to a free end having a tapered peak. The method further includes providing a lower crown portion having at least one annular lower rib extending to a free end having a tapered peak. Then, moving the upper crown portion and the lower crown portion toward one another and initiating contact between the upper crown portion and the lower crown portion at their respective tapered peaks. Then, continuing moving the upper crown and the lower crown further toward one another after making initial contact at their respective tapered peaks and forming a friction weld joint between the free ends of the at least one upper rib and the at least one lower rib free end.

Abstract: A rocking journal bearing is provided in a piston coupling mechanism of a two-stroke cycle engine. The bearing includes a sleeve and a wristpin constructed with two sets of eccentrically-disposed bearing surfaces which alternate in accepting a compressive load during an operational cycle of the bearing. The sleeve includes a network of grooves to transport oil to the bearing surfaces. Lubricating oil flow through the bearing is minimized by limiting provision of pressurized oil from the wristpin to the network of grooves to portions of the cycle when one or the other of the sets of bearing surfaces receives the compressive load.

Abstract: A rocking journal bearing is provided in a piston coupling mechanism of a two-stroke cycle engine. The bearing includes a sleeve and a wristpin constructed with two sets of eccentrically-disposed bearing surfaces which alternate in accepting a compressive load during an operational cycle of the bearing. The sleeve includes a network of grooves to transport oil to the bearing surfaces. Lubricating oil flow through the bearing is minimized by limiting provision of pressurized oil from the wristpin to the network of grooves to portions of the cycle when one or the other of the sets of bearing surfaces receives the compressive load.

Abstract: A piston assembly having a piston member and a connecting rod. The piston member has a crown portion and a lower portion bonded together with a cooling gallery formed between them. The connecting rod has a ball end which is positioned in a socket in the piston member. In one embodiment, the ball end can have two flat surfaces and be held in position by C-clips. In another embodiment, the ball end is cylindrically shaped and the socket has a corresponding shape.

Abstract: A piston for an internal combustion engine comprises a crown, a skirt section extending from the crown, and an oil ring groove. The piston further comprises a drain hole and a cooling channel. The drain hole extends from the oil ring groove to an inside space of the piston. The cooling channel is formed in the crown at a level above the oil ring groove, and arranged to covey a cooling oil. The cooling channel includes a channel segment which is located near the drain hole and which is formed to have a sectional shape avoiding the drain hole.

Abstract: A piston for an internal combustion engine, including a crown portion that defines a combustion chamber, a ring-shaped cooling channel formed in the crown portion, through which a cooling oil flows, and a plurality of concave portions formed on at least one side of the cooling channel, in an axial direction of the piston, each of the plurality of concave portions having a curved surface.

Abstract: Improvements in a combustion engine performance and reduced temperature of the combustion engine therefore resulting in an increase in the brake thermal efficiency where the pistons move linearly within the combustion cylinder. A pair of one-way clutches is used to convert the reciprocating linear motion into rotary motion without a crank shaft and without friction or power loss in the engine. High pressure oil is used to intercool the piston and the cylinder walls and is used for lubricating the piston ring. This configuration will improve the engine efficiency and reduce emission and result in a low cost engine.

Abstract: A thermocompression motor includes a piston dividing a cylinder into a first and a second chamber and includes a heat exchanger having at least one air channel and at least one exhaust gas channel. In a first cycle, the first and second chamber are connected via the air channel, whereby air from the first chamber is pushed into the heat exchanger and heated air is conveyed from the heat exchanger into the second chamber. In a second cycle, fuel is burned in the second chamber. In a third cycle, only the connection of the second chamber to the exhaust gas channel is open during a subsequent volume increase of the first chamber. In a fourth cycle, fresh air is sucked into the first chamber during a further volume increase of the first chamber, while the connection between the first and second chamber via the air channel is interrupted.

Abstract: Improvements in a combustion engine performance and reduced temperature of the combustion engine therefore resulting in an increase in the brake thermal efficiency where the pistons move linearly within the combustion cylinder. A pair of one-way clutches is used to convert the reciprocating linear motion into rotary motion without a crank shaft and without friction or power loss in the engine. High pressure oil is used to intercool the piston and the cylinder walls and is used for lubricating the piston ring. This configuration will improve the engine efficiency and reduce emission and result in a low cost engine.

Abstract: The present invention relates to a piston (10) for an internal combustion engine, having an outer circumferential cooling channel (19) and an inner cooling cavity (21), the cooling cavity bottom (22) of which has an opening (23) that is closed off with a separate closure element (33) that has at least one cooling oil opening (35), whereby the closure element (33) is held, in clamped manner, by means of two engagement elements (37) disposed on the outer edge, in at least one engagement groove (34) provided in the region of the opening (23) of the cooling cavity bottom (22). According to the invention, it is provided that the closure element (33) has at least two spring tabs (38) that support themselves on a contact surface (39) provided in the piston interior, in each instance, in such a manner that the closure element (33) is held in the engagement groove (34) under axial bias.

Abstract: The piston engine cooling system includes multiple pistons rotatably coupled to a crankshaft. Each piston includes a piston head defining a cooling chamber therein, and a connecting rod coupled to the piston head. The connecting rod includes a connecting rod inlet channel therein allowing oil to enter the cooling chamber, and a connecting rod outlet channel receiving oil exiting the cooling chamber. The crankshaft defines a crankshaft inlet channel allowing oil to flow through the connecting rod inlet channel, and a crankshaft outlet channel receiving oil flowing through the connecting rod outlet channel.