A pneumatic engine includes first and second pneumatic motors. Each motor has a stator, a rotor, and a gas flow path. The rotor is rotatably connected to the stator. The gas flow path is defined at least in part by the stator and the rotor, and extends from a gas inlet to a terminal gas outlet. The gas flow path has an expansion portion extending between the gas inlet and an intermediate gas outlet, and a compression portion extending between the intermediate gas outlet and the terminal gas outlet. The terminal gas outlet of the first pneumatic motor is fluidly connected upstream of the gas inlet of the second pneumatic motor.

A rotary engine casing having at least one end wall of an internal cavity for a rotor including a seal-engaging plate sealingly engaging the peripheral wall to partially seal the internal cavity and a member mounted adjacent the seal-engaging plate outside of the internal cavity. The member and seal-engaging plate having abutting mating surfaces which cooperate to define between them at least one fluid cavity communicating with a source of liquid coolant. When the casing includes a plurality of rotor housings, the end wall may be between rotor housings. A method of manufacturing a rotary engine casing is also discussed.

A rotary internal combustion engine including a rotor assembly where at least a first and a second of the combustion chambers have unequal theoretical volumetric ratios. Also, a rotary internal combustion engine including first and second rotor assemblies where at least one of the combustion chambers of the first rotor assembly and at least one of the combustion chambers of the second rotor assembly have unequal effective volumetric compression ratios and/or unequal effective volumetric expansion ratios.

A method and system is provided for pressure balancing one or more seals in machines such as expanders and/or compressors using the process fluid which is being expanded or compressed to provide the pressure for pressure balancing the other side of the one or more seals. The one or more seals may be part of a pressure containing chamber which may comprise a seal, a bearing and/or a gear on a rotating shaft common to the seal. An amount of pressure to be supplied to housing(s) for a machine so as to create a pressure cascade, and thereby dropping the pressure in each subsequent chamber as pressure approaches atmosphere. Pressure differentials may be directed to leak process fluid to the chamber into the process. Pressurized lube oil systems may be employed for balancing pressure and delivering lubricant to the seals, bearings and gears.

A method for the noise modulation of a three-phase synchronous electric motor driven using a vector regulation by means of a motor control unit. Actual values for the rotated current components i.sub.d and i.sub.q may be obtained in an open-loop control system, where i.sub.d corresponds to the magnetization current and i.sub.q corresponds to the torque-forming current of the synchronous motor. The actual values may be compared with predetermined reference target values, and the differences between the actual values and the reference target values may be converted into control variables to regulate the actual values (i.sub.q, i.sub.d) to the reference target values. The magnetization current-forming current component (i.sub.d) may be adapted using an acoustic controller to a desired acoustic state depending on an acoustic state that was measured by a measuring device and was transmitted to the motor control unit.

A compound cycle engine having at least one rotary unit defining an internal combustion engine, a first stage turbine in proximity of each unit, and a turbocharger is discussed. The exhaust port of each rotary unit is in fluid communication with the flowpath of the first stage turbine upstream of its rotor. The rotors of the first stage turbine and of each rotary unit drive a common load. The outlet of the compressor of the turbocharger is in fluid communication with the inlet port of each rotary unit, and the inlet of the second stage turbine of the turbocharger is in fluid communication with the flowpath of the first stage turbine downstream of its rotor. The first stage turbine has a lower reaction ratio than that of the second stage turbine. A method of compounding at least one rotary engine is also discussed.

A compound engine assembly including a common air conduit having an inlet in fluid communication with ambient air, a compressor, at least one internal combustion engine having an inlet in fluid communication with an outlet of the compressor, a turbine section having an inlet in fluid communication with an outlet of the at least one internal combustion engine, the turbine section configured to compound power with the at least one internal combustion engine, and at least one heat exchanger in fluid communication with the common air conduit, each of the at least one heat exchanger configured to circulate a fluid of the engine assembly in heat exchange relationship with an airflow from the common air conduit circulating therethrough. The compressor has an inlet in fluid communication with the common air conduit upstream of the at least one heat exchanger. The internal combustion engine may be a reciprocating engine.

A compound cycle engine having an output shaft, at least two rotary units each including an internal combustion engine with the rotor of each rotary unit mounted on the output shaft and in driving engagement therewith, and a turbine including a rotor in driving engagement with the output shaft. The exhaust port of each rotary unit housing is in fluid communication with the flowpath of the turbine upstream of its rotor. The turbine is disposed co-axially between two of the rotary units. The engine may further include a compressor in fluid communication with the inlet port of each housing and a second turbine having an inlet in fluid communication with the flowpath of the first turbine downstream of its rotor. A method of compounding rotary engines is also discussed.

An engine assembly including an internal combustion engine, an impulse turbine, and an exhaust pipe providing fluid communication between the exhaust port of the internal combustion engine and the flow path of the turbine. The exhaust pipe terminates in a nozzle. A ratio Vp/Vd between the pipe volume Vp and the displacement volume Vd of the internal combustion engine is at most 1.5. A minimum value of a cross-sectional area of the exhaust pipe is defined at the nozzle. In one embodiment, a ratio An/Ae between the minimum cross-sectional area An and the cross-sectional area Ae of the exhaust port of the internal combustion engine is at least 0.2. A method of compounding at least one internal combustion engine is also discussed.

A cylinder is installed within a case, and an output shaft and an arm that is integrated thereto and extends in a radial direction are installed within the cylinder. A piston extending in an arc slides and is displaced in a circumferential direction of the cylinder within the cylinder. One end portion of the piston is rotatably connected to the arm. The cylinder is internally provided with a first pressure chamber in which the arm is housed and a second pressure chamber in which the other end portion of the arm is slidably installed. A pressure medium is fed into one of the first and second pressure chambers and discharged from the other, and the output shaft pivots in a rotational direction.