A rotary-piston engine comprises a housing (4), a cylinder (5), a combustion chamber (10), a piston (11) with a device (12) for the reciprocating movement of the piston, and a rotor (1) connected to an output shaft (9). The rotor (1) is mounted on hinges (2), and sealing partitions (3) are provided both around the edge of the perimeter and on the sides, inside the housing (4). The cylinder (5) is provided with intake, exhaust and scavenging ports (6, 7, 8). Working combustion chambers (10) are provided on the outer surface of the rotor (1) in the form of recesses. Said recesses are configured to admit the entrance of truncated heads of pistons (11). The pistons (11) are arranged in a circle around the rotor (1) and move reciprocally in the cylinders (5) in a two- or four-stroke internal combustion engine working mode by means of device (12), which is connected to the working shaft (9).

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

An engine includes a housing and a combustion assembly. The combustion assembly includes an annular bore and a combustion piston assembly disposed within the annular bore. The combustion piston assembly includes a set of pistons, a first sealing ring connected to each piston and a second sealing ring connected to each piston. The second sealing ring is configured to provide selective access between the annular bore and at least one fluid conduit carried by the engine. The engine includes at least one valve configured to move between a first position within the annular bore to allow the combustion piston assembly to travel within the annular bore from a first location proximate to the at least one valve to a second location distal to the at least one valve and a second position within the annular bore to define a combustion chamber.

An energy transfer machine includes a piston and cylinder. The piston can have a rocking motion as it enters and exits the cylinder, for example due to one being on a rotor and the other on a stator. The piston and cylinder form a primary chamber, and as they move relative to each other can form a seal separating the primary chamber into first and second sub-chambers which then unseals before the piston exits the cylinder. The first sub-chamber may reach a maximum geometric compression ratio, for example for the purpose of compression ignition, before the unsealing of the sub-chambers.

An energy transfer machine includes a piston and cylinder. The piston can have a rocking motion as it enters and exits the cylinder, for example due to one being on a rotor and the other on a stator. The piston and cylinder form a primary chamber, and as they move relative to each other can form a seal separating the primary chamber into first and second sub-chambers which then unseals before the piston exits the cylinder. The first sub-chamber may reach a maximum geometric compression ratio, for example for the purpose of compression ignition, before the unsealing of the sub-chambers.

A rotational engine system comprises a rotational engine and a propulsion system. The rotational engine includes an outer ring enclosure, an inner ring component, and a drive gear. The inner ring component includes a piston and a drive gear engagement portion. The piston is configured to travel within the outer ring enclosure along a circumference of the outer ring enclosure. The drive gear engagement portion is configured to rotate as the piston travels along the circumference of the circular shape of the outer ring enclosure. The drive gear is coupled to the drive gear engagement portion of the inner ring component such that rotation of the drive gear engagement portion rotationally drives the drive gear. The propulsion system is configured to deliver propulsive energy to propel the piston along the circumference of the outer ring enclosure.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have a first hub disposed thereon with a plurality of cavities. At least one contour is slidably received into an arcuate cavity in an exterior surface of the hub. The contour has a convex outer surface that cooperates with an inwardly facing curved surface of a housing to form a working volume.

A compound engine system includes a rotary engine with rotating chambers, a compressor section in successive communication with the rotating chambers, and a turbine section in successive communication with the rotating chambers. The turbine section has an output shaft. The output shaft and the engine shaft are drivingly engaged to each other and wherein the turbine section has a power output corresponding to from 20% to 35% of a total power output of the compound engine system. A method of compounding power in a compound engine system is also discussed.