An aircraft engine has a hollow driveshaft with a spool coaxial with the driveshaft and extending through the driveshaft to rotate independently of the driveshaft. A first harmonic cam is mounted on the driveshaft and a second spaced apart harmonic cam is mounted on the spool. At least one combustion cylinder is positioned between the cams along a combustion cylinder axis that is parallel with but radially spaced apart from the driveshaft. A piston assembly is disposed in each end of the combustion cylinder, with each piston assembly engaging a separate cam. A high-pressure compressor turbine is mounted on the driveshaft and driven by movement of a piston assembly, compressing air for the combustion cylinder. A rotating component is mounted on the spool and driven by movement of the other piston assembly. The rotating component may be another compressor turbine, a drive turbine, a fan or a propeller.

A hybrid engine having a plurality of combustion power assemblies disposed about an engine driveshaft on which is mounted spaced apart cams, each combustion power assembly disposed between the cams radially outward of the driveshaft and having a combustion cylinder with a fuel injector mounted thereon and with a reciprocating piston assembly disposed in each end of the combustion cylinder. A cam follower is attached to each piston assembly and engages a respective cam. An electric power assembly may be mounted radially outward from the driveshaft and adjacent at least one cam as a radial power assembly or may be mounted along the driveshaft between the two cams as an axial power assembly.

A hybrid engine having a plurality of combustion power assemblies disposed about an engine driveshaft on which is mounted spaced apart cams, each combustion power assembly disposed between the cams radially outward of the driveshaft and having a combustion cylinder with a fuel injector mounted thereon and with a reciprocating piston assembly disposed in each end of the combustion cylinder. A cam follower is attached to each piston assembly and engages a respective cam. An electric power assembly may be mounted radially outward from the driveshaft and adjacent at least one cam as a radial power assembly or may be mounted along the driveshaft between the two cams as an axial power assembly.

An aircraft engine has a hollow driveshaft with a spool coaxial with the driveshaft and extending through the driveshaft to rotate independently of the driveshaft. A first harmonic cam is mounted on the driveshaft and a second spaced apart harmonic cam is mounted on the spool. At least one combustion cylinder is positioned between the cams along a combustion cylinder axis that is parallel with but radially spaced apart from the driveshaft. A piston assembly is disposed in each end of the combustion cylinder, with each piston assembly engaging a separate cam. A high-pressure compressor turbine is mounted on the driveshaft and driven by movement of a piston assembly, compressing air for the combustion cylinder. A rotating component is mounted on the spool and driven by movement of the other piston assembly. The rotating component may be another compressor turbine, a drive turbine, a fan or a propeller.

Aspects of the present invention relate to a carriage assembly (3-n) for a swash plate engine (1) having a swash plate (7). The carriage assembly (3-n) has a carriage body (19) for reciprocating along a longitudinal axis (X-n). The carriage body (19) is configured to be connected to at least one piston (5-n). At least one bearing assembly (20-n) is disposed on the carriage body (19). The or each bearing assembly (20-n) includes a rolling bearing (21-n) configured to engage a rolling face of the swashplate (7); and a yoke (23-n) for supporting the rolling bearing (21-n). The yoke (23-n) is movable relative to the carriage body along the longitudinal axis. Aspects of the present invention also relate to a swash plate drive assembly (15); and a swash plate engine (1).

Aspects of the present invention relate to a carriage assembly (3-n) for a swash plate engine (1) having a swash plate (7). The carriage assembly (3-n) has a carriage body (19) for reciprocating along a longitudinal axis (X-n). The carriage body (19) is configured to be connected to at least one piston (5-n). At least one bearing assembly (20-n) is disposed on the carriage body (19). The or each bearing assembly (20-n) includes a rolling bearing (21-n) configured to engage a rolling face of the swashplate (7); and a yoke (23-n) for supporting the rolling bearing (21-n). The yoke (23-n) is movable relative to the carriage body along the longitudinal axis. Aspects of the present invention also relate to a swash plate drive assembly (15); and a swash plate engine (1).