A volumetric expander comprising a casing having a general inlet and outlet, a piston operating inside the casing and adapted to define an expansion chamber with variable volume, a main shaft connected to the piston, and a valve for selectively opening and closing an inlet and an outlet of the expansion chamber allowing: a condition of introduction of the working fluid in the expansion chamber, a condition of expansion of the working fluid in the expansion chamber, and a condition of discharge of the working fluid from said expansion chamber. The casing defines a discharge chamber in direct communication with the general outlet and configured for being put in direct fluid communication with the outlet of the expansion chamber during the condition of discharging the working fluid from the expansion chamber itself. The casing comprises an auxiliary inlet which is in communication with the discharge chamber of the casing and with the general outlet; the auxiliary inlet is configured for enabling the working fluid to directly enter the casing.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

A four-stroke rotary-piston engine has an outer disk, and inner disk, at least one cylinder, at least one piston, at least one piston rod, a fixed gear engaged with a planet gear and a rotary gate valve positioned at a head of the cylinder. The inner disk is rotatable with respect to the outer disk by a compression control device. The planet gear rotates a crank situated on a shaft thereof. The shaft passes upwardly through the inner disk. The crank reciprocates a lever via the piston rod. The lever has an end pivoted on the outer disk so as to push the piston into and out of the cylinder.

In an internal combustion engine, first and second rotating members, one for the intake valve and one for the exhaust valve rotate next to the outside of an engine cylinder on opposite sides thereof when driven by a drive gear attached to the end of the engine's crankshaft. Each rotating member may include a ring gear having a valve port or aperture near its perimeter that cyclically aligns with a corresponding valve port formed through the cylinder wall near the top of the cylinder. A method of controlling valve timing comprises the steps of causing the rotating member containing the second valve port to periodically align in synchronism with the first port to control the passage of an air/fuel mixture and exhaust gases through the combustion cycles of the engine.

A cylinder head assembly for an internal combustion engine includes: a cylinder head defining a combustion chamber and having at least one opening communicating therewith; at least one port; at least one rotatable valve element disposed between the at least one opening and the at least one port; and at least one seal assembly disposed between the at least one rotatable valve element and the cylinder head, the seal assembly comprising a seal having a concave sealing face which conforms to a peripheral surface of the at least one valve element, a labyrinth seal disposed opposite the sealing face, and a resilient secondary seal disposed between the seal and the cylinder head.

A valve arrangement for controlling the flow of gasses (132, 138) through a cylinder (128) of an internal combustion engine, which includes an inlet shaft (120) having an inlet flow channel defined therein, an outlet shaft (122) having an outlet flow channel defined therein, the inlet and outlet shafts (120, 122) being mounted rotatably about an inlet and outlet port of the cylinder (128) respectively, wherein the flow of gasses through the cylinder is controlled as the shafts are rotated between a first position wherein the flow channels are in register with the cylinder ports, thereby allowing the flow of gasses (132, 133) through the cylinder (128), and a second position wherein the flow channels are deregistered relative the cylinders ports, so as to inhibit the flow of gasses through the said cylinder.

A valve arrangement for controlling the flow of gasses (132, 138) through a cylinder (128) of an internal combustion engine, which includes an inlet shaft (120) having an inlet flow channel defined therein, an outlet shaft (122) having an outlet flow channel defined therein, the inlet and outlet shafts (120, 122) being mounted rotatably about an inlet and outlet port of the cylinder (128) respectively, wherein the flow of gasses through the cylinder is controlled as the shafts are rotated between a first position wherein the flow channels are in register with the cylinder ports, thereby allowing the flow of gasses (132, 133) through the cylinder (128), and a second position wherein the flow channels are deregistered relative the cylinders ports, so as to inhibit the flow of gasses through the said cylinder.

An intake device of an internal combustion engine, includes: a plurality of intake ports which have outer walls and partition walls and are adjacent to each other via the partition walls; a valve body which is provided in each of the intake ports, and switches a flow path of the intake port by rotation around a rotation shaft; a holding member which is installed on each of the outer walls and the partition walls; and a rolling bearing which is mounted on at least one of the holding members, and supports the valve body to be freely rotatable, wherein the holding member includes a wall surface between the rolling bearing and the valve body in a direction in which the rotation shaft extends.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The piston may be configured to move in the cylinder in a work stroke from one end to another. The work stroke may include an expansion stroke portion and a non-expansion stroke portion. The non-expansion stroke portion may include a momentum stroke portion, and a compression stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. Passageways in the piston rod portions may be configured to communicate gases between a combustion chamber and other locations.