Pressure changing devices and methods of making and using the same are disclosed. One pressure changing device includes an elliptic cylinder and a piston that has an external surface with a trochoid cross-section. Another pressure changing device includes a piston and a rotating cylinder that has an internal surface with a trochoid cross-section. Another pressure changing device includes two fixed axes, one for rotation of one component and another for orbiting or oscillation of the other component. The devices and methods include stacked pressure changing devices with one or more common shafts. The pressure changing device may be easier and less expensive to manufacture and repair than prior pressure changing devices of the same or similar functionality, and can provide efficient gap sealing in a high-pressure expansion part of a compression or expansion cycle.

A rotary piston and cylinder device having a rotor, a stator and a shutter disc, the rotor including a piston which extends from the rotor into the cylinder space, the rotor and the stator together defining the cylinder space, the shutter disc passing through the cylinder space and forming a partition, and the disc having a slot which allows passage of the piston, the shutter disc having a circumferential surface that forms a seal with the rotor, the circumferential surface defining at least one close running line with the rotor, and the at least one close-running line offset from a rotor plane which lies on a radius of the rotor and which includes the axis of rotation of the rotor.

An assembly for an aircraft having a propeller, including a wheel well for a retracted landing gear, first and second cooling ducts; and an engine assembly having an engine shaft configured for driving engagement with the propeller, the engine assembly including a coolant circulation system for circulation of a liquid coolant, a lubricant circulation system for circulation of a lubricant, a first heat exchanger in fluid communication with at least the coolant circulation system, and a second heat exchanger in fluid communication with at least the lubricant circulation system. Each heat exchanger is positioned and configured for receiving a cooling airflow from the respective cooling duct. The wheel well is located between the heat exchangers. A method of cooling a lubricant and a liquid coolant of an engine assembly is also discussed.

An assembly for an aircraft having a propeller, including a wheel well for a retracted landing gear, first and second cooling ducts; and an engine assembly having an engine shaft configured for driving engagement with the propeller, the engine assembly including a coolant circulation system for circulation of a liquid coolant, a lubricant circulation system for circulation of a lubricant, a first heat exchanger in fluid communication with at least the coolant circulation system, and a second heat exchanger in fluid communication with at least the lubricant circulation system. Each heat exchanger is positioned and configured for receiving a cooling airflow from the respective cooling duct. The wheel well is located between the heat exchangers. A method of cooling a lubricant and a liquid coolant of an engine assembly is also discussed.

A rotary engine including a housing and housing head enclosing a combustion chamber, a piston including an output shaft and a piston disk within the housing and rotatable on a piston rotation axis, a quadrant within the housing and around the piston and rotatable on a quadrant rotation axis, wherein the quadrant rotation axis is acutely angled to the piston rotation axis, and a post surrounding a segment of the piston disk. The post pivots relative to the piston about a post-piston rotation axis that is normal to the face of the piston disk. The post pivots relative to the quadrant about a post-quadrant pivot axis that is perpendicular to the quadrant rotation axis. The post rotates about the quadrant rotation axis relative to the housing. Combusting fuel injected into the combustion chamber expands and pushes on the piston disk to rotate the output shaft about the piston rotation axis.

A rotary engine including a housing and housing head enclosing a combustion chamber, a piston including an output shaft and a piston disk within the housing and rotatable on a piston rotation axis, a quadrant within the housing and around the piston and rotatable on a quadrant rotation axis, wherein the quadrant rotation axis is acutely angled to the piston rotation axis, and a post surrounding a segment of the piston disk. The post pivots relative to the piston about a post-piston rotation axis that is normal to the face of the piston disk. The post pivots relative to the quadrant about a post-quadrant pivot axis that is perpendicular to the quadrant rotation axis. The post rotates about the quadrant rotation axis relative to the housing. Combusting fuel injected into the combustion chamber expands and pushes on the piston disk to rotate the output shaft about the piston rotation axis.

A rotary internal combustion engine includes outer and inner housings defining an enclosure therebetween, and first and second side housings disposed on opposite sides of the outer housing. The inner housing is rotatable relative to the outer housing, at least one retractable barrier and at least one fixed barrier. The at least one retractable barrier and the at least one fixed barrier are disposed in the enclosure so as to divide the enclosure into a combustion chamber and an exhaust chamber. The at least one retractable barrier is mounted along a pivot axis and is pivotable between an extended position and a retracted position. An intake port, exhaust port, and ignition source are also provided. An exhaust duct extends from within the enclosure to outside the outer housing in a direction tangent to flow in the enclosure.

A rotary internal combustion engine includes outer and inner housings defining an enclosure therebetween, and first and second side housings disposed on opposite sides of the outer housing. The inner housing is rotatable relative to the outer housing, at least one retractable barrier and at least one fixed barrier. The at least one retractable barrier and the at least one fixed barrier are disposed in the enclosure so as to divide the enclosure into a combustion chamber and an exhaust chamber. The at least one retractable barrier is mounted along a pivot axis and is pivotable between an extended position and a retracted position. An intake port, exhaust port, and ignition source are also provided. An exhaust duct extends from within the enclosure to outside the outer housing in a direction tangent to flow in the enclosure.

A high efficiency reciprocating engine, nominally of the internal combustion type but alternatively of the external combustion type is disclosed. The new engine uses Hypocycloidal and alternatively Epicycloidal gear mechanisms to create differentiated compression and expansion ratios which then promote significant improvements in efficiency through lower compression losses and higher extraction of available energy. Through suitable augmentation, the engines can be made to provide higher power when needed over higher efficiency. Additionally, other parameter modifications enable realization of low side wall loads and true zero exhaust volume.

An oil seal member is provided at an outside surface of a member performing whirling motion such as a rotary engine rotor. A sliding face of the oil seal member that slides relatively to a stationary-side member is provided with a step extending circumferentially, and has a relatively high surface formed on one radial side with respect to the step and a relatively low surface on the other radial side. The high surface is provided with pumping grooves to pump oil tending to leak from the high surface side into the low surface side, into the high surface side by sliding relatively to the stationary-side member.