A compound engine assembly with an engine core including at least one internal combustion engine, a compressor, and a turbine section where the turbine shaft is configured to compound power with the engine shaft. The turbine section may include a first stage turbine and a second stage turbine. The turbine shaft is rotationally supported by a plurality of bearings all located on a same side of the compressor rotor(s) and all located on a same side of the turbine rotor(s), for example all located between the compressor rotor(s) and the turbine rotor(s), such that the compressor rotor(s) and the turbine rotor(s) are cantilevered. A method of driving a rotatable load of an aircraft is also discussed.

A method of cooling a gas fueled engine driven intercooled air compressor comprises providing the intercooled air compressor, a gearbox, and the gas fueled engine. The method includes flowing a liquid coolant from a liquid coolant supply to each of the gearbox and an intercooler of the intercooled air compressor. The method comprises recombining the liquid coolant after the gearbox and the intercooler. The method includes directing the recombined liquid coolant via multiple paths to cool the gas fueled engine. The method comprises recombining the liquid coolant after the liquid coolant has passed through the multiple paths.

A method of cooling a gas fueled engine driven intercooled air compressor comprises providing the intercooled air compressor, a gearbox, and the gas fueled engine. The method includes flowing a liquid coolant from a liquid coolant supply to each of the gearbox and an intercooler of the intercooled air compressor. The method comprises recombining the liquid coolant after the gearbox and the intercooler. The method includes directing the recombined liquid coolant via multiple paths to cool the gas fueled engine. The method comprises recombining the liquid coolant after the liquid coolant has passed through the multiple paths.

An auxiliary power unit assembly for an aircraft, including an engine assembly including an internal combustion engine, a first duct in fluid communication with an inlet of the internal combustion engine and configured to be in fluid communication with an environment of the aircraft, and a second duct configured to be in fluid communication with the environment. The second duct may be in fluid communication with an inlet of a compressor drivable by the internal combustion engine or with a compartment receiving the engine assembly. A filter extends across the first duct. The filter is removable from the first duct through an opening in a wall of the first duct, the opening accessible from an exterior of the engine assembly.

An auxiliary power unit assembly for an aircraft, including an engine assembly including an internal combustion engine, a first duct in fluid communication with an inlet of the internal combustion engine and configured to be in fluid communication with an environment of the aircraft, and a second duct configured to be in fluid communication with the environment. The second duct may be in fluid communication with an inlet of a compressor drivable by the internal combustion engine or with a compartment receiving the engine assembly. A filter extends across the first duct. The filter is removable from the first duct through an opening in a wall of the first duct, the opening accessible from an exterior of the engine assembly.

A gas-cycle system operable using a Bell-Coleman cycle, the gas-cycle system comprising an expander (23) and a compressor (27) incorporated in a flow path (13). The expander (23) and compressor (27) are integrated in a rotary machine (41), and each comprises a rotor assembly (70) configured to define one or more zones (80) each of which changes continuously in volume during a rotation cycle of the rotor assembly. The expander (23) and compressor (27) are drivingly interconnected whereby rotational drive applied to one is transmitted directly to the other. Each rotor assembly (70) comprises an inner rotor (73) and an outer rotor (75) adapted to rotate about parallel axes at different rotational speeds. The inner rotors (73) are each drivingly connected to a common shaft for rotation therewith. The two outer rotors (75) are coupled together such that rotational drive applied to one is transmitted directly to the other. An air-cycle system and an air conditioning system (10) based on the gas-cycle system are also disclosed.

A gas-cycle system operable using a Bell-Coleman cycle, the gas-cycle system comprising an expander (23) and a compressor (27) incorporated in a flow path (13). The expander (23) and compressor (27) are integrated in a rotary machine (41), and each comprises a rotor assembly (70) configured to define one or more zones (80) each of which changes continuously in volume during a rotation cycle of the rotor assembly. The expander (23) and compressor (27) are drivingly interconnected whereby rotational drive applied to one is transmitted directly to the other. Each rotor assembly (70) comprises an inner rotor (73) and an outer rotor (75) adapted to rotate about parallel axes at different rotational speeds. The inner rotors (73) are each drivingly connected to a common shaft for rotation therewith. The two outer rotors (75) are coupled together such that rotational drive applied to one is transmitted directly to the other. An air-cycle system and an air conditioning system (10) based on the gas-cycle system are also disclosed.

The invention relates to a circulatory assistance system comprising: a rotor in the shape of a Reuleaux triangle; and a camshaft received in a housing of the rotor and designed to rotate the rotor about an axis of rotation. The inner walls of the housing of the rotor are in contact at all points with the outer surface of the cam such that the assembly formed by the cam and the rotor does not have a clearance volume.

The invention relates to a circulatory assistance system comprising: a rotor in the shape of a Reuleaux triangle; and a camshaft received in a housing of the rotor and designed to rotate the rotor about an axis of rotation. The inner walls of the housing of the rotor are in contact at all points with the outer surface of the cam such that the assembly formed by the cam and the rotor does not have a clearance volume.

A fluid expander is disclosed as used in conjunction with an air compressor that is driven by a prime mover. The fluid expander is structured to extract useful work from a fluid stream and add that work to the work provided by the prime mover to the compressor. In some embodiments a clutch can be used to decouple the expander from the compressor if insufficient work is developed by the expander. A gear train can also be used to change the rotational speed prior to work being delivered to the compressor.