Abstract: A turbine engine system utilizes one or more augmented combustion modules to produce an exhaust that is fed into the turbine portion of the engine and wherein power is produced by the augmented combustion module for use to drive the main shaft and/or for auxiliary purposes. An augmented combustion module is configured between the compressor and the turbine of the engine and receives compressed air from the compressor and ignites an air/fuel-mixture to turn a shaft that can be used to produce power. The shaft may be coupled with an electrical power generator, a pump, a hydraulic or pneumatic power generator and/or power conversion or transmission devices and/or coupled with the main shaft of the turbine engine. The power from a power generator may be stored in a battery, hydraulic accumulator or pneumatic accumulator and may be used to power auxiliary electrical, hydraulic or pneumatic devices.

Abstract: Engines and methods execute a high efficiency hybrid cycle, which is implemented in a volume within an engine. The cycle includes isochoric heat addition and over-expansion of the volume within the engine, wherein the volume is reduced in a compression portion of the cycle from a first quantity to a second quantity, the volume is held substantially constant at the second quantity during a heat addition portion of the cycle, and the volume is increased in an expansion portion of the cycle to a third quantity, the third quantity being larger than the first quantity.

Abstract: An internal combustion rotary engine includes an air passage configured to allow cool air to flow through the rotor as the rotor moves relative to the housing within the engine. Some embodiments include a removable fuel cartridge.

Abstract: In one aspect, described is a rotary engine having a purge port located rearwardly of the inlet port and forwardly of the exhaust port along a direction of the revolutions of the rotor, the purge port being in communication with the exhaust port through each of the chambers along a respective portion of each revolution, and the inlet and outlet ports being relatively located such that a volumetric compression ratio of the engine is lower than a volumetric expansion ratio of the engine.

Abstract: A method of feeding air to an internal combustion engine having at least first and second internal cavities, including: completing the intake phase of the first combustion chamber of the first internal cavity by feeding compressed air into the first combustion chamber until a maximum volume thereof is reached; during a beginning of the compression phase of the first combustion chamber and a simultaneous beginning of the intake phase of the second combustion chamber of the second internal cavity, feeding compressed air from the first combustion chamber into the second combustion chamber; closing a communication between the first and second combustion chambers and completing the intake phase of the second combustion chamber by feeding compressed air into the second combustion chamber until a maximum volume thereof is reached.

Abstract: According to preferred embodiments and methods of the present disclosure, a medical injection system employs a single pump for the injection of multiple fluids, rather than employing a pump for each type of fluid, for example, like the prior art system described above. Embodiments of pumps disclosed herein preferably include a disposable pump cartridge configured to be contained within a hull of a medical injection system, wherein the hull may be formed when a pressure plate member is closed against a base plate; and, when the pressure plate member is opened with respect to the base plate, the disposable pump cartridge may be removed and replaced.

Abstract: An internal combustion engine with rotatable bodies each received in a respective internal cavity. The engine includes at least one inlet port for each internal cavity in fluid communication with the combustion chamber(s) thereof at least during their intake phase and a beginning of their compression phase. The bodies are angularly offset with the beginning of the compression phase of the combustion chamber(s) defined by each body being simultaneous with at least a beginning of the intake phase of the combustion chamber(s) defined by a different one of the bodies. A respective conduit provides a fluid communication between an inlet port for each body and an inlet port for the different one of the bodies, with each conduit being in fluid communication with a plenum for receiving pressurized air. A method of feeding air to an internal combustion engine is also provided.

Abstract: The inventive concept is directed to a “COMPEL” system. The word compel is an acronym of the words “compressed air and electricity”. The compel system is a system of mechanical devices aligned together to propel a vehicle without employing any fossil fuel and creating very little or no detectable pollution. The motion source is a single electric engine that drives the vehicle by way of a transmission. The source/s for producing the electricity originate in two different manners. One source is of the motion of the vehicle itself and responsible for the action of the second source. Conversely, the second source provides the energy to propel the vehicle, Thus, each source is generally dependent upon the other. However, the holding reserve capacity of the fuel tank allows for the compressed air engine source to mobilize the vehicle from a dead stop and thereby re-engage the other generating source/s. The other energy generating sources are elements driven by the axle of the vehicle.

Abstract: A stator for a rotary internal combustion engine, with a body having an internal cavity. Each end wall has a scavenging cavity defined therein in fluid communication with the internal cavity through a respective scavenging opening extending through the inner surface thereof, and at least one annular oil seal groove defined in the inner surface thereof concentric with the central bore and located radially outwardly of the scavenging opening. At least one annular oil seal is received in each groove and protrudes from the end wall into the internal cavity for sealing engagement with a surface of a rotor of the engine, each seal being biased axially away from the end wall. A rotary internal combustion engine and a method of limiting radially outwardly directed oil leaks in a rotary engine are also disclosed.

Abstract: A hybrid internal combustion engine (variants thereof) comprises a casing having an annular working chamber with intake, exhaust ports, and overflow channels; and two drive shafts coaxial with the working chamber; a stationary central gear wheel; an output shaft having an offset portion fixedly carrying a carrier and a planetary gear; connecting rods pivotally connecting the carrier and the arms of both drive shafts, wherein the overflow channels are adjacent to the working chamber and connect the compression and expansion sections thereof.

Abstract: An engine, such as a circulating piston engine, includes a housing that defines an annular bore, a piston assembly, and a valve. The piston assembly is disposed within the annular bore and is configured to be coupled to a drive mechanism. The valve is configured to be intermittently disposed within the annular bore to define a combustion chamber relative to the piston assembly.

Abstract: A positive displacement internal combustion engine with the strongest mechanism for converting thermal energy of combustion gases to rotational motion, being composed of a body with spherical combustion chamber, and three spatial eccentrics being placed in said spherical chamber. The mechanism is particularly suitable for heavily loaded detonation and homogeneous charge compression ignition engines.

Abstract: A rotary engine which provides a supplemental phase of compression between a first phase of compression and a second phase of compression.

Abstract: A split-cycle variable capacity rotary spark ignition engine system having at least a first rotary configuration (C1) including repetitively volume variable working chambers [60, 61, 62] for carrying out the combustion-expansion and exhaust phases and at least a second rotary configuration (C2) including repetitively volume variable working chambers (70, 71, 72) for carrying out the intake and compression phases of a four phase engine cycle. Dividing seal means (73, 74 of C1, 75, 76 of C2) for periodically dividing each of successive working chambers into a volume enlarging leading portion and a volume contracting trailing portion. Discharge valve means for varying compression chamber capacity through discharging fraction of trapped intake gas from compression chambers. A first phase altering arrangement is provided for varying the phase relation between the first rotary configuration (C1) and the second rotary configuration (C2).

Abstract: An inverse displacement asymmetric rotary engine is provided which includes a chamber. The chamber includes a stationary island having an island outer surface. The outer surface is an elongated convex shape. The island includes a crankshaft port spaced from a center of the island. The chamber includes a front-plate attached to a front surface of the island. A concave shaped movable contour is include, which is biased toward the island outer surface and which revolves about the island. A working volume is defined between an inner surface of the contour and the outer island surface. At least one front-plate engaging bearing is provided, which extends from a front surface of the movable contour and over a guide edge of the front-plate. The front-plate engaging bearing engages the guide edge during a combustion cycle.

Abstract: A rotary internal combustion diesel engine (46) comprising: a posterior plate (78), an intermediate plate (80), and an anterior plate (82); a rotor-housing unit (46) on each side of the intermediate plate (80), each containing a yousroid chamber (48), and a 2-apex rotor (56) containing an aperture (58). The chamber (48) wall contains an intake valve (68), an exhaust valve (70), and a fuel supply device (72); in gasoline embodiments, an ignition device (76) is added; compressed air/gas and hydraulic embodiments, require an input port (74) and an output port (70a). A shaft (52) rotatably mounted, extends through the housing, having essentially rectangular segments (54) within the chambers (48). There are seals (not shown) on the rotor apices (60, 62) and on the anterior (82) intermediate (80), and posterior plate (78).

Abstract: A “TurboMotor” positive displacement rotary-piston machine comprises a casing having an annular working chamber and intake and exhaust ports, two drive shafts coaxial with the annular surface defining the working chamber and provided with rotary pistons on one end thereof and with arms on the other end thereof, a stationary central gear coaxial with the surface defining the working chamber and with the drive shafts, an output shaft concentric with the drive shafts and having an offset portion carrying a carrier and a planetary gear, the planetary gear being in mesh with the stationary central gear the carrier being pivotally connected to the arms of both drive shafts through the connecting rods. The annular working chamber of the casing communicates with the intake ports and exhaust ports and/or exit channels and entrance channels arranged sequentially and contiguously.

Abstract: A planetary engine includes a charge compression system for compressing a charge of air and/or an air and fuel mixture that is precompressed by rotation of the rotors and supplied into a combustion chamber through a rotary valve that may be actively adjusted during operation of the engine to vary the intake valve opening size and/or timing. Exhaust valves may likewise be actively adjustable rotary valves for further engine control. A compression insert mounted between the end wall assemblies absorbs combustion forces and provides rigidity to the engine, as well as occupies all or nearly all of the volume between the rotors at the minimum volume of the combustion chamber to improve the compression ratio of the engine.

Abstract: The invention relates to heat engines and more specifically to positive displacement internal combustion engines, and is particularly concerned with oscillating engines i.e. engines, in which piston executes oscillating motion. The invention provides the optimal, “canonical” form for the two stroke oscillating engine of unique strenght and compactness.

Abstract: A rotary piston engine includes a generally triangular rotor, a pair of side housings, a rotor housing which is assembled with the rotor and the pair of side housings to define three working chambers, an intake port formed in at least one of the side housings, and an exhaust port formed in at least one of the side housings. The length of one side of the triangular face of the rotor is at least 2.4 times the breadth of the rotor.

Abstract: The inventive volume expansion rotary piston machine includes a body (1) with a circular working cavity which is provided with and intake and exhaust channels (18, 19) and in which bladed pistons (5, 6) are disposed on two coaxial shafts (2, 3). Said shafts have arms (4) which are connected, by means of connecting rods (10), to crankshafts with planet toothed wheels which are fastened to said crankshafts and are engaged with a fixed central toothed wheel (12). The volume expansion rotary piston machine comprises an output shaft (7) with an eccentric (8) on which a planet wheel (11) with a carrier (9) are rigidly connected and mounted, and which planet wheel is kinematically connected to the arms (4) of the two shafts (2, 3) by means of the connecting rods (10).

Abstract: The invention provides the proper form for the rotary positive displacement internal combustion engine. The construction of the engines according to the invention is based on a specific form of four bar mechanism and features unique simplicity (only three moving parts, no valves or camshafts, no gears to transfer piston movement to rotary movement), compactness and strength that make the engines according to the invention similar in these and some other aspects (e.g. power density) to gas turbines.

Abstract: The invention relates to a microsystem for converting a difference in pressures in a fluid into mechanical movement, this microsystem comprising:—an inlet nozzle (6) for compressed fluid and an outlet nozzle (8) for expanded fluid,—at least two arms (12, 14), at least one of which is hinged and between which flows the fluid in order to pass from the inlet nozzle to the outlet nozzle by moving these arms with respect to one another, the arms (12, 14) being designed and hinged such that, while they move, they define at least one pocket of fluid which is moved away from the inlet nozzle in order then to return to the outlet nozzle while at the same time increasing in volume, each of the arms (12, 14) being mechanically connected to a single plane (20).

Abstract: A Wankel-type rotary engine comprising a longitudinal housing divided on two parts by a partition having a window, a rotor passed through the window and engaged with an end wall sliding in the cavity, and forming together with the cavity, end wall and partition working chambers, and a means for moving the rotor along the cavity.

Abstract: An internal combustion rotary engine has a chamber defined by a chamber wall and a rotor valve body in three locus-sealing contact with the chamber wall to define a series of three subchambers including a first subchamber for sequential compression, transfer, and combustion of a fuel mixture from a chamber fuel mixture intake and for exhausting combustion products through a chamber exhaust outlet. The rotor body defines a first bodily internal path for fuel mixture travel from the intake to the first subchamber for compression and combustion to combustion products, and a second bodily internal exhaust travel path between the combustion products in the first subchamber and the chamber exhaust outlet for exhausting of the combustion products. The chamber and rotor cooperate to transfer compressed fuel mixture past the rotor within the first subchamber. The rotor further defines a sealing and sliding valve structure with the chamber wall for controlling intake into and exhaust from the first subchamber.

Abstract: The invention regards to a method for providing a thermo-dynamic cycle of the internal combustion engine (1), with double center of rotation, for better exploitation of the propulsion in the phase of combustion from the mixture gas, characterized from the fact that the same phase of combustion and expansion, beyond that of to produce the greatest power request for the entire combustion, allows to contemporarily activate the succession at its channels, therefore finishing the expected inlet stroke of compression of the air for the successive cycle of combustion, particularly optimising the inlet stroke, that is realized in different times and channels, to guarantee the necessary depression for the acquisition of the greatest volume of air, to then meet in the compression chamber, determining the especially most favourable compression ratio.

Abstract: A rotary piston machine 10 includes an enclosure 12 having a cavity 14 therein with arcuate side walls 16a,b,c defining a plurality of arcuate recesses 18a,b,c and a piston member 20 rotationally disposed in the cavity 14. The piston member 20 includes opposite ends 42 and 43 configured to rotationally engage the arcuate side walls 16a,b,c and the arcuate recesses 18a,b,c such that compression chambers 26a,b,c are ultimately formed via the piston member ends 42 and 43 cooperatively engaging two arcuate recesses 18a,b,c.

Abstract: Engines and methods execute a high efficiency hybrid cycle, which is implemented in a volume within an engine. The cycle includes isochoric heat addition and over-expansion of the volume within the engine, wherein the volume is reduced in a compression portion of the cycle from a first quantity to a second quantity, the volume is held substantially constant at the second quantity during a heat addition portion of the cycle, and the volume is increased in an expansion portion of the cycle to a third quantity, the third quantity being larger than the first quantity.

Abstract: A rotary engine and a hydraulic motor including non-rotary outer and inner casings; a power shaft with an eccentric part; a driving eccentric ring between the outer and inner casings and mounted on the eccentric part; a combustion or pressure chamber between the eccentric ring and the inner casing such that the eccentric ring drives the power shaft by substantially non-rotating eccentric movement; dividers for dividing the combustion chamber into at least two parts, the dividers extend through the inner casing and are in contact with an inner surface of the driving eccentric ring; and an eccentric device (or control) for driving the dividers back and forth with respect to the inner casing. The eccentricity of the eccentric device corresponds with the eccentricity of the eccentric part of the power shaft. The eccentric device has a guide groove which implements an eccentric path and to which the dividers are connected.

Abstract: A power unit (14) which has a spark-ignition engine unit (1) of the Wankel type including a three flanked rotary piston (R) mounted on an eccentric shaft (63) rotating eccentrically within a cavity within a two lobed epitroochoidal inner peripheral surface (14), the cavity including an inlet port (7) through which air at ambient pressure is induced into the working chambers, and an outlet port (45) through which exhaust gasses are exhausted from the working chambers, and the power unit also including a rotary expander unit (4) which has a two flanked rotor (24) mounted on an eccentric shaft (12) rotating eccentrically within a single lobed epitrochoidal chamber (25), both shafts (62, 63) being coupled to rotate together, and the exhaust port (45) of epitrochoidal cavity of the engine unit (1) being connected to an inlet port (26) of the expander unit (4) so that the exhaust gasses from the engine unit (1) are further expanded in the expander unit (4).

Abstract: Internal Combustion Engine, Rotary Engine Type, with Distinct Conception, Durability and Performance, Applied to all Types of Vehicle or Industrial Equipment, represented by an inventive solution of a rotary engine, which aggregates value by promoting a distinct conception and reliability to an engine based on the functional concept of this nature, thus providing a greater durability to the engine, levering the same one to a condition of singular competitiveness, where to this attribute be obtained, its innovation is related to a constructive concept based on the formation of a set of divisors components (17), mainly divisors components of chambers, which are distinct by promoting a radial movement with perpendicular angle (?2) constant equal to 90° related to the internal cavity of the jacket (6), which is perfectly cylindrical, in all kinematics of movement, which describes its functionality, mainly when it describes the phases of intake; compression; explosion/expansion and also depletion, respectively, be

Abstract: The problems of prior compressor structures relying upon conventional check valves are obviated by using, instead, flow control passages which operate to control flow while avoiding mechanical moving elements which may become problematical.

Abstract: An internal combustion rotary engine using vanes to create separate combustion chambers within the engine and capable of performing all four strokes of the Otto cycle (intake, compression, combustion and exhaust) in each separate combustion chamber. Each Otto cycle is completed in a 180-degree rotation with all four strokes of the Otto cycle being completed in 720 degrees. An intake and exhaust valve system tightly controls the flow of the air/fuel mixture into each separate combustion chamber.

Abstract: Star Engine is a four stroke internal combustion engine, which converts the eccentric motion of the center of the rotor directly to a rotary motion of a main shaft. This engine is formed by the principle a small circle rolling inside a larger one (FIG. 1). The star shape of both the rotor and stator are formed by the ratio between them (FIG. 2).

Abstract: The invention relates to heat engines and more specifically to positive displacement internal combustion engines, and is particularly concerned with rotary and oscillating spherical engines i.e. engines, in which piston executes rotary/oscillating motion and combustion chamber and principal engine's parts that converts gas pressure into rotary movement assume general form of sphere. The invention provides the optimal, “canonical” form for the two stroke rotary and oscillating spherical engine of unique strength and compactness.

Abstract: The invention relates to a rotary piston engine with a frame, a cylinder liner mounted rotatably in the frame, a rotor mounted coaxially in the cylinder liner and a gear mechanism connecting the frame, the cylinder liner and the rotor, where the gear mechanism is outside a working space arranged between cylinder liner and rotor and where the gear mechanism couples the cylinder liner and the rotor for a relative movement periodically oscillating between positive and negative rotational speed.

Abstract: The invention provides the proper form for the rotary positive displacement internal combustion engine. The construction of the engines according to the invention is based on a specific form of four bar mechanism and features unique simplicity (only three moving parts, no valves or camshafts, no gears to transfer piston movement to rotary movement), compactness and strength that make the engines according to the invention similar in these and some other aspects (e.g. power density) to gas turbines.

Abstract: A planetary engine includes a charge compression system for compressing a charge of air and/or an air and fuel mixture that is precompressed by rotation of the rotors and supplied into a combustion chamber through a rotary valve that may be actively adjusted during operation of the engine to vary the intake valve opening size and/or timing. Exhaust valves may likewise be actively adjustable rotary valves for further engine control. A compression insert mounted between the end wall assemblies absorbs combustion forces and provides rigidity to the engine, as well as occupies all or nearly all of the volume between the rotors at the minimum volume of the combustion chamber to improve the compression ratio of the engine.

Abstract: A rotary piston engine includes a generally triangular rotor, a pair of side housings, a rotor housing which is assembled with the rotor and the pair of side housings to define three working chambers, an intake port formed in at least one of the side housings, and an exhaust port formed in at least one of the side housings. The length of one side of the triangular face of the rotor is at least 2.4 times the breadth of the rotor.

Abstract: A powertrain for driving a motor vehicle includes an internal combustion engine including first and second rotors supported for rotation about an axis, a first epicyclic gear unit including a first component fixed against rotation, a first driving component, and a first driven component, a first power path alternately producing a first drive connection between the driven component and the first rotor, and opening said first drive connection, and a second power path producing a second drive connection between the driven component and the second rotor, and opening said second drive connection.

Abstract: The rotary engine includes a cylinder body having a cylinder chamber, an intake port, an exhaust port, and a spark plug, and a rotor which is received in the cylinder chamber to eccentrically rotate while coming into contact at seal faces thereof with an inner circumferential contact wall of the cylinder chamber to thereby implement intake, compression, expansion, and exhaust strokes. The rotor has an elliptical outer contour, and the inner circumferential contact wall of the cylinder chamber coincides with a specific curve, which is described by opposite apexes of the elliptical rotor in a direction of a major axis, when the rotor eccentrically rotates. The intake port and exhaust port are provided with opening/closing valves, respectively. Sealing performance between the cylinder chamber and the rotor may achieve an enhancement in the efficiency of fuel combustion and engine output and prevent waste of fuel.

Abstract: An apparatus for an aspiration plate for a rotary internal combustion engine. The engine has three rotating members that orbit about the center of a three-armed rotor as the rotor rotates within a housing with three lobes. The tips of the rotating members engage the lobes and a circular cutout in the rotor as the rotor rotates. A back, or aspiration, plate includes inlet and exhaust ports that are sequentially opened and closed by the rotating members and rotor as they move within the housing. A front plate rotates with the rotor and separates the combustion chambers from a planetary gear assembly that ensures the alignment of the rotating members as they orbit the rotor shaft. Fuel is injected after the compression cycle is initiated.

Abstract: The invention relates to a hydraulic motor having an outer casing and eccentric means for rotating a power shaft by means of fluid through a pressure chamber arrangement. The eccentric means comprise an eccentric part formed in the power shaft, a first eccentric ring between the outer casing and an inner casing, and a second eccentric ring mounted with bearings around the eccentric part and connected fixedly and concentrically to the first eccentric ring, whereby the pressure chamber arrangement is located between the first eccentric ring and the inner casing so that the first eccentric ring drives the power shaft through the second eccentric ring, and the eccentric rings form a substantially non-rotating entity that only performs an eccentric movement and by means of this eccentric movement rotates the power shaft.

Abstract: A counter-rotating 2 cycle piston engine with a combustion chamber and an output shaft rotatably mounted to rotate independently about the same propeller centerline of an aircraft. The Internal combustion power is transmitted to the output shaft by means of a conventional piston, rod, crankshaft configuration journaled to the combustion chamber or engine block in the traditional manner thereby producing concurrent rotation of the shaft and counter-rotation of the engine block. Interior surfaces of the combustion chamber and pistons are angled to control the oil flow inside the crankcase and eliminate unwanted ponding. The pistons are modified to transfer fluid accumulations to the combustion chamber. A throttle is located at the axis of rotation to function normally without the effects of centrifical force.

Abstract: An engine including a housing formed with a pair of side-by-side intersecting substantially cylindrical cavities, and a pair of counter-rotating power rotors rotatably mounted within the cavities. The pair of power rotors include intermeshing lobes that each define open ended combustion chambers.

Abstract: A rotary piston machine having a housing defining a prismatic chamber the cross section of which forms an oval of odd order. A rotary piston is guided in the chamber and, in each position, subdivides the chamber into two working chambers. Piston-fixed instantaneous axes of rotation of the rotary piston are defined in a center plane. The rotary piston, in each interval of movement, is rotating with one of opposite nappe sections in an inner wall section about an associated instantaneous axis of rotation and is sliding with the opposite nappe section along the opposite second inner wall section of the chamber and is reaching a stop position there.

Abstract: The present invention is a novel hydraulic/electric, rotating interface for torque producing engines, including internal combustion engines, which enables a rigidly mounted motor to isolate the power/torque producing components from other stationary accessories, to provide advantageous crankshaft/block counter-rotational output, suitable for torque free power applications, torque free propulsion and torque sensitive environments.

Abstract: A rotary combustion engine includes a driving eccentric ring arranged between a non-rotary outer casing and a non-rotary inner casing for rotating a power shaft situated inside the inner casing. In order to drive the eccentric ring, a combustion chamber arrangement is provided between the inner and the outer non-rotary casings for burning a mixture of fuel and air supplied thereto, the power shaft being provided with an eccentric element. In order to minimize the number of rotating components, a second eccentric ring is mounted by a bearing around the power shaft inside the aforementioned non-rotary inner casing, this second ring being coaxial with and fixed to the driving eccentric ring, and the eccentric ring arrangement being a substantially non-rotary unit that only performs an eccentric motion, which makes the power shaft rotate.

Abstract: There is provided a rotary internal combustion engine (20) comprising a plurality of rotors (21) each having a plurality of lobes (22) for intermeshing with lobes of other rotors to form successive combustion chambers. Axial seal elements (60, 61) are provided at the rotor tips and trailing tips of the rotors respectively. Circumferential axial edge seals (59) are also provided to interconnect the axial seals. The seals engage sealing plates (30) on each axial side of an engine housing (29) so as to effect the combustion chambers. Fuel inlets and ignition means are provided at suitable locations, as are exhaust means.

Abstract: A counter-rotating rotary-piston engine has an output shaft with a cylindrical inner cavity rotatably mounted on a single support spindle in the frame of an aircraft. The output shaft extends substantially through the length of the engine block, which is suitably journaled on the shaft or the spindle to permit its counter-rotation. Internal combustion power is transmitted to the output shaft by means of an inner rotary piston fixed to the shaft which cooperates in conventional manner with an outer working chamber in the engine block, thereby producing concurrent rotation of the shaft and counter-rotation of the engine block. Dual propellers mounted on the shaft and on the block improve thrust performance, balance the torques and moments of inertia of the two counter-rotating masses, and virtually eliminate any resultant torque to the aircraft.