Abstract: The invention provides a pair of co-rotating fluid powered wheel and generator pairs each rotating about a single vertical axis. Each wheel/generator is mounted on a respective axle one of which is solid and the other tubular. Separation of fluid flow into 2 streams engages the wheels for rotation in opposite directions. Folding paddles collapse and extend to engage the moving fluid.

Abstract: The drive device is provided for inclusion in a windmill with two counter-rotating screws. The shafts of the screws are each connected to a spindle of an epicyclical gearbox, the third spindle providing the energy for the user. The device further comprises a brake device simultaneously acting on the two shafts of the screws. In particular, said device permits the installation of a second screw on a windmill mast designed for a single screw on a windmill mast designed for a single screw, thus greatly increasing the power supplied.

Abstract: A device and method having a rotor head with a rotor input/output shaft, a rotor drive cap, an upper rotor/propeller hub, upper blades and a driver bevel gear; an idler assembly connects the upper rotor/propeller hub to a lower rotor/propeller hub, lower blades and an idler bevel gear; and a static assembly with a main rotor shaft, an idler pinion carrier and an idler pinion shaft. The rotor head and the idler assembly rotate utilizing bevel gear idlers in opposite directions about the static assembly to cause the upper blades and lower blades to rotate in opposite directions.

Abstract: A method for assembling a gas turbine engine that includes providing a low-pressure turbine inner rotor that includes a first plurality of rows of turbine blades configured to rotate in a first rotational direction, providing a low-pressure turbine outer rotor that includes a second plurality of rows of turbine blades configured to rotate in a rotational direction that is opposite the first rotational direction, and coupling a support structure between the outer rotor and a turbine mid-frame such that the support structure supports a forward end of the outer rotor, and wherein the support structure includes a first portion that has a first coefficient of thermal expansion and a second portion that has a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion.

Abstract: A single-shaft dual-direction fan assembly includes a shaft and two fan rotors each mounted on an end of the shaft respectively. The two fan rotors each include a plurality of fan blades, and the fan blades of the two fan rotors are curved toward reverse direction respectively. A motor couples with the shaft to drive the two fan rotors to rotate synchronously so as to generate a dual-directional airflow.

Abstract: A turbo pneumatic cylinder of a pneumatic tool, including a front turbine, a one-way rotatable inverse turbine and a rear turbine. The front and rear turbines are mounted on the rotary shaft of the pneumatic cylinder. The inverse turbine is one-way rotatably fitted on the rotary shaft between the front and rear turbines. Multiple blades are arranged on the circumferences of the front and rear turbine and the inverse turbines. The blades of the inverse turbine are directed in a direction reverse to the direction of the blades of the front and rear turbines. The front and rear turbines and the rotary shaft rotate in the same direction, while the inverse turbine rotates in a direction reverse to the direction of the front and rear turbines. As a result, the efficiency of the pneumatic cylinder is enhanced and the twisting of the pneumatic cylinder is avoided when it is in operation.

Abstract: A counter-rotating fan includes first and second fans that are coaxially arranged. The first ribs of the first fan and the second ribs of the second fan are arranged on an air-outlet side and an air-inlet side of the first impeller of the first fan, respectively. The first impeller includes first blades. When seen in an axial direction from the second fan side, while the first rib side edge of each first blade is at least partly located above one first rib, the second rib side edge of that first blade is not located below any second rib but is entirely located between two second ribs. Thus, interference of air taken in by the first blades with the second ribs and interference of air sent out by the first blades with the first ribs cannot occur simultaneously, resulting in improvement of the sound characteristics of the counter-rotating fan.

Abstract: A compressor or pump employs principles of unsteady delayed stall to enhance the head increase produced by the compressor or pump. Plural airfoil-shaped lifting elements are spaced from each other in a cascade and the fluid is directed into the cascade by a device that varies a parameter of the flow relative to each lifting element in repeating cycles to cause the flow relative to each lifting element to begin to separate from the lifting element and then reattach thereto during each cycle. The cascade can comprise an axial flow impeller with plural impeller blades arranged around a hub capable of rotating on an axis. The device for varying the flow parameter can be a stator with a plurality of stator blades upstream of the impeller, or a second, counter-rotating axial flow impeller. In either case, the parameter is a flow angle at which the flow is directed to the downstream impeller.

Abstract: A rotor hub fairing system includes an upper hub fairing, a lower hub fairing and a shaft fairing therebetween. The rotor hub fairing system is sized and configured to reduce the overall drag on a dual, counter-rotating, coaxial rotor system. Preferably, the rotor hub fairing is fully integrated. The shaft fairing preferably includes a minimal thickness at the midsection to reduce drag with an increasing thickness adjacent the upper and lower hub fairings to reduce the flow separation on the hub fairing surfaces without overly excessive drag. Other aerodynamic structures, such as a horizontal splitter and/or a plurality of turning vanes may be mounted to the shaft fairing to facilitate flow around the upper and lower hub fairings to reduce flow separation and drag.

Abstract: A dual, counter rotating, coaxial rotor system provides an upper and lower rotor system, with a reduced axial rotor separation distance along a common axis by way of rotor tip position sensing and rotor position controls to avoid tip contact.

Abstract: Methods and apparatus for assembling a gas turbine engine are provided. The method includes coupling a first turbine shaft that includes m rows of turbine blades within the gas turbine such that the first turbine shaft is rotatable in a first direction, and coupling a second turbine shaft that includes n rows of turbine blades within the gas turbine such that the second turbine shaft is rotatable in a second direction wherein a torque split between the first and second turbine shafts is substantially proportional to the number of rows of turbine blades on each shaft relative to a total number of rows of blades on both shafts, and wherein m and n are selected to provide a torque split between the first turbine shaft and second turbine shaft of greater than about 1.2:1.

Abstract: An axial-flow fan with double impellers is provided that can produce a larger amount of air and a higher static pressure than can be achieved with conventional fans. The axial-flow fan with double impellers has a first axial-flow fan unit and a second axial-flow fan unit. The first axial-flow fan unit includes a first case, a first impeller and a plurality of webs that fix a first motor to the first case. The second axial-flow fan unit includes a second case, a second impeller and a plurality of webs that fix a second motor to the second case. The first case and the second case are coupled together to form a housing. The webs of the first axial-flow fan unit and the webs of the second axial-flow fan unit are combined together to form a plurality of stationary webs arranged in the housing. The number of front blades provided at the first impeller is set to five, the number of stationary blades is set to three, and the number of rear blades provided at the second impeller is set to four.

Abstract: A coaxial counter-rotating rotor system for a hybrid aircraft includes an upper swashplate assembly and a lower swashplate assembly with a coaxial transmission system therebetween. Movement of the upper and lower swashplate assembly is reflected about a midplane of the coaxial transmission housing to generate sufficient cyclic and/or collective pitch inputs within a compact structural in which the rotor systems are closely spaced along an axis of rotation.

Abstract: A dual, counter rotating, coaxial rotor system provides an upper and lower rotor system, with a reduced axial rotor separation distance along a common axis by way of rotor tip position sensing and rotor position controls to avoid tip contact.

Abstract: A rotor system for a gas turbine engine is provided having an outer rotor which includes an annular outer spool that comprises at least one ring portion of increased thickness with respect to the remainder of the outer spool, attached to a relatively thinner, axially extending arm portion. A plurality of outer turbine blades are attached to the ring portion of the outer spool and extend radially inwardly into a working gas flowpath of the engine. A casing surrounds the outer spool and defines an annular cavity between the casing and the outer spool, which is sealed by forward and aft brush seals at the forward and aft ends thereof. At least one inlet port is formed through the casing for admitting a flow of cooling air to the annular cavity. Means are provided for directing this cooling air flow to the ring portion of the outer spool.

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: A marine vessel includes a rudder support structure attached to its hull and a rudder device attached to the rudder support structure in a manner allowing pivotal movement of the rudder device relative to the rudder support structure. A first drive train includes a first propeller shaft mounted in the hull and extending from the hull. A first propeller unit is attached to the first propeller shaft and is positioned forward of the rudder device. A second drive train includes a second propeller shaft that is mounted rotatably in the rudder support structure and a second propeller unit is attached to the second propeller shaft. The second propeller unit is aft of the first propeller unit and coaxially aligned therewith.

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 double-ended variable speed blower for Continuous Positive Airway Pressure (CPAP) ventilation of patients includes two impellers in the gas flow path that cooperatively pressurize gas to desired pressure and flow characteristics. Thus, the double-ended blower can provide faster pressure response and desired flow characteristics over a narrower range of motor speeds, resulting in greater reliability and less acoustic noise.

Abstract: Multiple, timed three-lobed rotor that are more efficient yet uncomplicated and easy to produce. A rotor lobe with additional reaction surfaces near the tip to increase the angle of rotation that produces power. A “flow through” rotor having end plates that facilitate mounting more than one rotor on a common axis with rotationally varied timing and sequence, such that power delivery is smooth. A flow shielding and directing device that increases the efficiency of reaction surface rotors. Possibilities include replacement or augmentation of: existing electrical energy prime mover dynamos, air compressing, pumping, milling, and other power needs. The dynamo can be built using low-tech, low-cost materials and methods, and is inherently resistant to over speed and damage from periodically high velocity fluid flow.

Abstract: An aircraft gas turbine engine includes a low pressure turbine having a low pressure turbine flowpath and low pressure inner and outer shaft turbines with counter rotatable low pressure inner and outer shaft turbine rotors, respectively. The low pressure inner and outer shaft turbine rotors include low pressure first and second turbine blade rows disposed across the turbine flowpath which are drivingly connected to first and second fan blade rows by low pressure inner and outer shafts, respectively. At least one row of low pressure variable vanes is operably disposed across the low pressure turbine flowpath between the low pressure inner and outer shaft turbines. The low pressure first turbine blade rows of the low pressure inner shaft turbine may be in tandem with or interdigitated with the second turbine blade rows of the low pressure outer shaft turbines.

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.

Abstract: Several synergistic improvements to a prime mover Dynamo including: A three-lobed rotor that is more efficient yet uncomplicated and easy to produce. A rotor lobe with additional reaction surfaces near the tip to increase the angle of rotation that produces power. A “flow through” rotor having end plates that facilitate mounting more than one rotor on a common axis with rotationally varied timing and sequence, such that power delivery is smooth. A flow shielding and directing device that increases the efficiency of reaction surface rotors mounted on a common axis by blocking flow to the back side of reaction surfaces, and extracting stagnant fluid through vanes that are energized by redirected free stream fluid flow, whereby increased torque and smother operation are evident verses typical prime mover dynamos.

Abstract: An aircraft gas turbine engine includes a low pressure turbine having a low pressure turbine flowpath and counter rotatable low pressure inner and outer shaft rotors having inner and outer shafts, respectively. The low pressure inner and outer shaft rotors include low pressure first and second turbine blade rows disposed across the turbine flowpath and drivingly connected to first and second fan blade rows by low pressure inner and outer shafts, respectively. At least one of the low pressure first and second turbine blade rows is interdigitated with an adjacent pair of one of the turbine blade rows. At least one row of non-rotatable low pressure vanes is disposed across the low pressure turbine flowpath between a non interdigitated adjacent pair of one of the turbine blade rows.

Abstract: The present invention provides a method and apparatus for serial coolant flow control. In one embodiment of the present invention, two or more sets of angled rotating blades are used in series to increase the coolant pressure and flow. In this embodiment, the rotational direction of a set of blades is the reverse of the rotational direction of any set of blades next to it. In one embodiment, the angles of the blades are such that the forward velocity created by a set of blades is in the same direction as forward velocities created by other sets of blades in the system. In one embodiment, the blades of one set form a right angle with the blades of any set next to it. In one embodiment, the coolant flow controller is a fan. In another embodiment, the coolant is air. In yet another embodiment, the system being cooled is an electronic system.

Abstract: An array of axially spaced rotating airfoils having funnel strips on the blades to increase the lift to drag ratio and generate thrust are rotatably driven by small motors with rotating airfoils, also having funnel strips to enhance thrust. The small motors are mounted on the tips of one set of rotating airfoils, or on an auxiliary drive member, so as to provide rotational torque for the array, thereby amplifying thrust generated by the fluid motor.

Abstract: Contra-rotating members are used for straightening a fluid flow. The members may take the form of propellers, fans or impellers. The contra-rotation eliminates tangential flow components, and most importantly, eliminates cylindrical vortices. The present invention finds specific use in applications in which toroidal vortices are employed and/or generated.

Abstract: A fan assembly includes a first fan and a second fan. The first fan has a first housing and a first blade assembly. The first blade assembly includes a plurality of blades attached to a hub, and is configured to rotate about a first axis of rotation in a first direction. The second fan includes a second housing and a second blade assembly. The second blade assembly also includes a plurality of blades attached to a hub. The second blade assembly, however, is configured to rotate about a second axis of rotation in a second direction that is opposite the first direction of rotation. The first axis of rotation and the second axis of rotation can be coincidental or they can be slightly offset.

Abstract: Contra-rotating members are used for straightening a fluid flow. The members may take the form of propellers, fans or impellers. The contra-rotation eliminates tangential flow components, and most importantly, eliminates cylindrical vortices. The present invention finds specific use in applications in which toroidal vortices are employed and/or generated.

Abstract: An axial turbine or axial compressor with bladed rotors (6, 7) rotating in opposite directions about a common axis, in particular for the expansion of steam and hot gases or for compressing gases, with mutually adjacent bladed rotors (6, 7) being mutually connected in a non-positive manner by way of the same toothed gearing (11, 12, 13, 14). In order to propose a respective design which allows applying the contra-rotating capability of axial flow turbines with a contra-rotating gear outside of the gear housing also in the case of several turbine wheels, and thus utilizing the aforementioned advantages which are inherent to this principle, namely of claiming higher pressure heads, it is provided that all bladed rotors (6, 7) rotating in the same direction of rotation are mutually connected by way of a rigid connecting element (5, 8).

Abstract: A marine propulsion assembly comprises a drive shaft, a first propeller fixed to the drive shaft and turnable therewith in a first direction, an annular array of gear teeth disposed on the first propeller and turnable therewith, a second propeller aligned with the first propeller, and an annular array of gear teeth disposed on the second propeller. Bevel gears are disposed between the first and second propellers and engaged with the first and second annular arrays of gear teeth. The bevel gears transmit rotation of the first propeller to the second propeller, such that the second propeller turns in an opposite direction relative to the first propeller.

Abstract: A propulsion device having fins rotating in opposing directions which are adjustable to avoid collision yet which provide opposing strokes similar to fishtails. At least one adjustable fin is connected at an end of a rotatable hollow primary axle which coaxially encompasses a secondary rotatable axle extending a distance from the end of the primary axle and having at least one adjustable fin at that end. Primary fins are adjusted distally during their trust segment of rotation and secondary fins are adjusted proximally during their thrust segment of rotation to enter a common thrust sweep zone. Fins are adjusted in a timed relationship to provide thrust while occupying the thrust sweep zone and thereafter adjusted out of the thrust sweep zone to avoid collision with opposing fins. Fins are additionally adjusted to assume a low resistance configuration during non thrust segments of rotation in order to reduce drag.

Abstract: A hollow portion is provided on the core of an inner shaft (2) to form an oil feed port (3), a plurality of oil feed holes (4) which are connected with both of the outer peripheral face of the inner shaft (2) within a range (L) of the bearing surface of the inner shaft (2) and the oil feed port (3) are radially provided in a line , and axial oil grooves (5) each of which includes an inner shaft surface side opening portion (4a) of the oil feed hole (4) are provided on the outer peripheral face of the inner shaft to form a contra-rotating bearing device for a contra-rotating propeller which causes the inner shaft (2) and an outer shaft (2) to contra-rotate mutually. In place of the oil grooves, a plurality of concave-convex portions may be formed in the axial direction of a contra-rotating bearing on the inner peripheral face of the bearing and circular portions may be provided on both axial ends of the concavo-convex portions to form the contra-rotating bearing device for a contra-rotating propeller.

Abstract: A counter-rotating fan which comprises a forward-skewed upstream rotor and a backskewed downstream rotor. The counter-rotating fan may be used in a cooling module with a heat exchanger, for example as an engine cooling fan in a vehicle.

Abstract: A split fan for providing lift for an aircraft is described. In one embodiment, a main engine shaft extends to the split fan, and a portion of the split fan is located at an elevation above the main engine shaft and a portion of the split fan is located at an elevation below the main engine shaft. In the one embodiment, the split fan includes an outer casing configured to be mounted to a fuselage of the aircraft, a first stage rotor including a shaft, a gear secured to the shaft, and a plurality of rotor blades radially extending from the shaft. The split fan also includes a second stage rotor including a shaft, a gear secured to the shaft, and a plurality of blades radially extending from the shaft. A drive shaft having a first end and a second end is coupled at the drive shaft first end to the main engine shaft.

Abstract: A marine propulsion device improves the handling characteristics and the responsiveness of the watercraft on which it is used. The propulsion device includes a pair of counter-rotating propellers. At least the blades of the front propeller each have a mean camber line in cross-section which has a generally constant radius of curvature. This blade shape reduces cavitations and permits the rear propeller to be mounted closer to the front propeller, and consequently closer to the steering axis of the outboard drive. As a result, steering torque is reduced. The blades of the rear propeller also are not more than thirty percent smaller than the blades of the front propeller, and the average pitches of the propellers do not differ by more than one to four percent. These blade configurations of the front and rear propellers improve the stability of the watercraft when turning, thereby reducing chine walk, as well as improve the responsiveness of the watercraft.

Abstract: The yaw control in an air vehicle having counter rotating rotors is provided by selectively and controllably applying a frictional drag or braking force to drive gears for the two rotors. Each of the drive gears includes a friction surface. Friction pads are located adjacent to and are releasably engagable with the friction surfaces of the drive gears. The friction pads are supported by a control mechanism for selectively moving each of the friction pads into engagement with the respective drive gear to provide a frictional drag on the drive gear and to a disengaged position spaced from the respective drive gear. The frictional forces created by engagement of the friction pads with the drive gear friction surfaces cause net torques on the air vehicle frame to rotate the air vehicle in the desired directions. Normally, the torque developed the counter rotating rotors is canceled, maintaining the air vehicle in the desired yaw orientation.

Abstract: A rotatable turbine frame includes annular outer and inner bands having a plurality of circumferentially spaced apart struts extending therebetween. An annular drive shaft is fixedly joined to the inner band for transmitting output torque therefrom, and the struts are backwardly radially inclined relative to the direction of rotation of the frame so that gas flow between the struts tends to straighten the inclined struts to effect a compressive load component therein.

Abstract: This invention is directed to stopped rotor Flipped Airfoil X-wing (FAX-WING.sup..TM.) aircraft which comprises:(a) A rotary wing flight mode which operates similar to a helicopter, wherein all main rotor airfoils rotate with leading edges into the oncoming airstream (neglecting forward motion) to provide lift, and utilize an anti-torque rotor to cancel main rotor torque. The fixed wing flight mode, including supersonic flight, utilizes all stationary main rotor airfoils for primary lift, such that all airfoil leading edges are positioned forward, meeting the oncoming airstream generated by forward aircraft motion. Two airfoils are forward swept 45 degrees, and the other two airfoils are aft swept 45 degrees. The transition mode for converting from rotary wing to fixed wing flight, and vise-versa, causes two adjacent airfoils to flip 180 degrees (in approximately 1/16 second) about their pitch axis, such that all airfoils have leading edges in the correct orientation for a particular flight mode.

Abstract: One embodiment of a coaxial transmission/center hub subassembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a single stage transmission, a transmission housing, and a center hub support structure that are structurally and functionally interactive. The transmission housing includes upper and lower standpipe housings secured in combination with a middle housing. The single stage transmission includes an input pinion gear rotatably mounted in combination with the middle housing, and upper and lower spiral bevel gears rotatably coupled in combination with the input pinion gear to provide counter-rotation thereof. The spiral bevel gears include integral rotor shafts, respectively, rotatably mounted in the standpipe housings.

Abstract: A propulsion system for a submerged vehicle which operates at a relatively low RPM includes a pair of coaxial drive shafts for producing counterrotating torques. A first propeller unit is attached for rotation with one of the drive shafts and a second propeller units is attached for rotation with the other drive shaft. Each propeller unit includes a plurality of arcuate propeller blades which are deployed upon rotation of their respective drive shaft. Specifically, this deployment is from a first configuration wherein the blades are disposed along the surface of the vehicle and into a second configuration wherein the blades are extended from the surface of the vehicle.

Abstract: A vertical lift aircraft comprising an aircraft body and a lifting assembly is presented. The lifting assembly comprises a frame wherein at least one airfoil assembly which includes a plurality of airfoils attached to a drive ring is secured. As the drive ring rotates, the airfoils move through the air and create lift. The pitch of the airfoils or blades can be fixed or variable. The drive ring is rotated by a band which is in frictional contact with the inner surface of the drive ring. The band is rotated by at least one pair of rollers which are in frictional contact with the band. Aircraft stability is controlled by regulating airfoil pitch which is responsive to pivoting of a control ring. Alternatively, aircraft stability is provided by regulating the flow of air or gas from a plurality of nozzles disposed about the aircraft. The body, a portion of which may be located inside the lifting assembly, includes a passenger and load carrying compartment and an engine assembly.

Abstract: A counterrotating turbine support assembly includes outer and inner rotors having respective outer and inner blades disposed in an outer casing. A mid-frame is disposed forwardly of the rotors and fixedly joined to the outer casing. A rear frame is disposed axially aft of the rotors and is fixedly joined to the outer casing. A forward support shaft is joined at one end to a forward end of the outer rotor and is rotatably supported at an inner end to the mid-frame by a forward bearing. An aft support shaft is joined at one end to an aft end of the outer rotor and is rotatably supported at an inner end to the rear frame by an aft bearing. An intermediate support shaft is fixedly joined at one end to the inner rotor and is rotatably supported at an inner end to the mid-frame by an intermediate bearing.

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12, 14). Inner and outer concentric counter-rotating propeller shafts (40, 42) are supported by a spool assembly (38) locked and retained against rotation and against axial movement in the lower horizontal bore (28) in the torpedo (34) of the drive housing (26) by axially spaced left and right hand threads (44 and 46). A thrust bearing assembly (98) transfers thrust from the outer propeller shaft to the inner propeller shaft during rotation of the propeller shafts in opposite axial direction and is axially located between fore and aft driven gears (76 and 78). Propeller shaft sealing and bearing structure, and propeller self-centering mounting structure is provided.

Abstract: A rotary airscrew having a central hub with coaxial first and second counter-rotating drive shafts, a first set of a plurality of non-lift blades connected to the first drive shaft for rotation to be rotated for moving air therewith, a second set of a plurality of primary airfoil blades connected to the second drive shaft, to be rotated counter to the rotation direction of the plurality of non-lift blades, and spaced apart from the non-lift blades with a small clearance distance to allow non-contacting counter-rotation, and a ring for supporting the first and second sets of blades with a small clearance distance between the ends as they are rotated.

Abstract: Two propeller shafts are disposed coaxially one within another. A collar of the inner propeller shaft grips into the hollow outer propeller and supports the inner shaft axially over axial friction bearing elements. The axial friction bearing elements are surrounded by a shaft connecting piece, which is divided in the axial direction and at least one half of which can be removed radially, in order to create access to the axial friction bearing elements. By way of the axial friction bearing elements, axial forces of the inner propeller shaft reach the hollow outer propeller shaft and, from the latter, by way of further axial friction bearing elements, further reach a bearing housing, which is preferably also divided in the longitudinal direction.

Abstract: A propeller system has a pair of hub assemblies driven in counter-rotation, each hub assembly having a mechanical pitch change actuator, each actuator being provided with a pitch lock that rotates simultaneously with the motion of the actuator to allow the actuator to set propeller blade pitch, but locks the propeller blade positionally when not rotating simultaneously with the actuator, and a differential for transmitting a pitch change signal across a rotating gap between the two hub assemblies and for providing power to a means for providing the pitch change signals. A pair of motors provide the rotative signal to set the pitch of the blades in each hub assembly. One of the pair of motors drives the actuator towards high pitch and the other motor drives the actuator towards low pitch. A synchronizer coordinates the signals of the first and second motors so that a pitch lock moves simultaneously with the actuator.

Abstract: A marine propulsion system is provided with dual counterrotating propellers, and a shaft and gear arrangement for driving the propellers. In a preferred embodiment, the marine propulsion system includes a depending gearcase having a steerable lower portion which is pivotable about a steering axis relative to an upper gearcase portion. A pair of coaxial drive shafts extend longitudinally through the gearcase, and are interconnected with the engine output shaft so as to rotate in opposite directions in response to rotation of the output shaft. The counterrotating propellers are preferably mounted to a pair of coaxial propeller shafts, and appropriate gearing is disposed between the coaxial propeller shafts and the coaxial drive shafts to drive the propeller shafts, and thereby the propellers, in opposite rotational directions. In a preferred embodiment, the gearing includes counterrotating gears fixed to the counterrotating drive shaft so as to provide cancelling gear torque loads about the steering axis.

Abstract: The disclosure describes a device for carrying and lifting loads and moving ame by aerodynamic lifting, rotary-wing aerial propulsion, having two coaxial rotors of same diameters rotating at the same speed and in reversed direction through a double crown wheel system which is driven by oppositely disposed rollers. The device includes a crown wheel operatively connected to two rotors which are driven by two rollers, one of which being driven by one or two motors mounted on the body. The internal crown wheel has a hub enabling external blades to be mounted in superimposed relationship.

Abstract: A marine stern drive for a boat (3) includes a propeller assembly (36) having a carrier (13) for a pair of concentric drive shafts (12, 19) to which are mounted a pair of closely adjacent fore and aft coaxial surface piercing propellers (21, 22) mounted on a common axis. The carrier also includes a downwardly extending skeg (31). The shafts are connected to a source of power (5) and drive the propellers in contra-rotating relationship at essentially equal rotational velocities. The carrier is connected to devices (39-41) for swinging the carrier laterally for steering, and also vertically. A control (45) is provided for positioning and maintaining the carrier vertically such that both contra-rotating propellers are continuously disposed in surface piercing position during normal operation of the drive. The result is that lateral forces created on the propeller carrier by one rotating surface piercing propeller are counterbalanced by the other propeller when the skeg is parallel to the boat centerline (4).