Abstract: A drive train for a wind turbine, comprising a main bearing arrangement in the form of a single locating bearing arranged to support a main shaft. An outer raceway of the main bearing is coupled to a support structure, such as a base frame of a nacelle, via flange parts arranged on the outer raceway and the support structure, respectively. The flange parts define interfacing surfaces extending in a plane which is arranged non-parallel, preferably substantially perpendicular, to the rotational axis of the main shaft. Thereby a service friendly design is obtained, in which the main bearing and/or the main shaft can be repaired and/or replaced without having to remove the rotor from the nacelle.

Abstract: A gearbox assembly (90) closely couples a fan-turbine rotor assembly (25) and an axial compressor rotor (46) to reduce the overall engine length and minimizes the number of engine bearings.

Abstract: A gas turbine engine is disclosed that includes a spool having a compressor section. An inlet case is arranged axially upstream from the compressor section. A gearbox is secured to the inlet case. The gearbox couples the spool and a fan. A sealing assembly is arranged between the inlet case and the gearbox to provide a sealed bearing compartment. The inlet case, gearbox and seal assembly provide a module. A fastening element removably secures the module to the spool. The gas turbine engine can be serviced by disconnecting the fastening element from the engine core. The gearbox and inlet case can be removed as a module from the engine core without disassembling the gearbox.

Abstract: A bamboo wind power megawatts producer is provided in which the surfaces of rotor blades capture and compress the laminar flowing wind through the turbulent rotor vortex wherein great amounts of energy are extracted from the wind in volumetric quantities within the confines of the housing assembly for rotating the power generators to produce great quantities of megawatts of electric currents after which the exhausted wind is dumped to the low pressure area leeward of the operating rotor assembly.

Abstract: A gear arrangement is disclosed herein. The gear arrangement includes a housing. The gear arrangement also includes a plurality of gears at least partially disposed in the housing and engaged with respect to one another. The gear arrangement also includes a support post mounted to the housing. The support post supports at least one of the gears. The support post has a first portion extending away from the housing and encircled by one of the gears. The support post also has a pin projecting away from the first portion. The first portion and the pin are eccentric to one another such that the first portion is centered on a first axis and the pin is centered on a second axis. The first and second axes are parallel to and spaced from one another. The gear arrangement also includes a plurality of pin apertures defined by the housing.

Abstract: A gearbox life estimation system includes a single sensor or multiple sensors configured for obtaining field operational data related to loading of a gearbox from a single gearbox component or different gearbox components. The system further includes a processor configured for receiving signals representative of the field operational data from the sensors, for providing calculated operational load data for the gearbox components based on the field operational data, and for providing an estimate of remaining life of gearbox using the calculated operational load data.

Abstract: A gas turbine engine including an electrical assembly operable as at least one of an electric motor and a generator, with an electromagnetic rotor formed in part by a portion of one of a main shaft concentrically and drivingly connected to at least one turbine rotor and a tower shaft directly driven by the main shaft and extending generally radially therefrom.

Abstract: Disclosed herein are screw shaft turbine compressors having (i) a compressor section, (ii) a turbine section, (iii) a combustion section coupling to the compressor section and the turbine section, and (iv) a grooved shaft. The grooved shaft can include one or more grooves for providing fuel from the compressor section to the combustion section and for allowing exhaust to leave the combustion section and exit the turbine section. A method for generating different speed to torque ratios on the shaft and a system for generating torque on the shaft are further disclosed.

Abstract: A method of emergency operation of an aircraft turbofan engine during an aircraft flight is provided. The engine includes a fan shaft with a fan, and an electric motor/generator mounted for rotation therewith. The method includes shutting down the engine while allowing the engine to windmill, operating the electric motor/generator to rotate the shaft at a determined windmilling speed which is desired for the fan shaft, and operating the engine at the desired windmilling speed for substantially a remainder of the aircraft flight.

Abstract: A turbomachine such as an aircraft turbojet including an electrical generator/starter that can be mounted and dismounted by axial translation in an upstream enclosure of the turbomachine between the low-pressure compressor and the high-pressure compressor, and couple to electrical cables which extend inside the structural arms of the intermediate casing of the turbomachine.

Abstract: An assembly between a turbine shaft and a stub axle of a turbomachine compressor shaft, the assembly including a substantially cylindrical compressor shaft stub axle, a substantially cylindrical turbine shaft disposed coaxially inside the compressor shaft stub axle, a mechanism for transmitting torque between the turbine shaft and the compressor shaft stub axle, and a clamping mechanism for clamping a downstream end of the turbine shaft to the compressor shaft stub axle. The compressor shaft stub axle has a plurality of teeth extending radially from its inside surface, and the turbine shaft is provided at its downstream end with a plurality of axial slots, the teeth of the stub axle co-operating with the slots of the turbine shaft.

Abstract: A shaft coupling device to couple first and second shafts, said device comprising a fluid coupling having a first portion attached to the first shaft and a second portion attached to the second shaft wherein the device further comprises engagement means operable to switch the device between an engaged position and a disengaged position, the engaged position having each of the first and second shafts engaged with its respective portion of the fluid coupling and the disengaged position having at least one of the first and second shafts disengaged from its respective portion of the fluid coupling.

Abstract: Systems, apparatus and methods for generating power from fluid motion, such as wind are provided. The apparatus is a wing-shaped airfoil with cup-shaped indentations that allow the airfoil to harness wind energy throughout a wide range of wind speeds and from different wind directions. The indentations harness wind energy at low wind speeds while the wing-shape generates a lifting force at high wind speeds to harness wind energy. The system comprises one or more of the devices configured in a hollow, generally cylindrical, shape and connected to a ring frame. The system rotates about an axis running through the center of the ring frame. The rotational motion of the system generates electrical power via a generator. The method is a method for generating electrical power from the rotational motion of the system.

Abstract: An actuator comprises an input shaft (42), a turbine system (38) coupled to the input shaft, air inlet means (32, 34) arranged to direct air flowing through it towards the turbine system to rotate the input shaft, an output shaft (50), and a gearing system (48) connecting the input shaft (42) to the output shaft (50) so that the turbine system (38) can drive the output shaft (50) via the gearing system (48). The air inlet means defines two different flow paths for air whereby the output shaft (50) can be driven in both directions.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: An apparatus for stabilizing a shaft in an essentially horizontal position while an anchoring object at one end of the shaft is replaced without removal of an object at the opposite end of the shaft that would otherwise tend to destabilize the shaft from its essentially horizontal position includes a half-spool member configured to clamp above and around the shaft to resist torque around the rotor, under supports configured to attach to the half-spool member and clamp an underside of the shaft below the half-spool member, and a hydraulic or mechanical brake configured to resist torque on the shaft when the brake is engaged.

Abstract: A first centrifugal impeller and a second centrifugal impeller are arranged in such an orientation that back sides of the first centrifugal impeller and the second centrifugal impeller face to each other. Bearings are cylindrical roller bearings and a thrust bearing. The cylindrical roller bearings are arranged at two axially spaced supporting positions respectively, and support a radial load applied to the rotating shaft. The thrust bearing supports a thrust load applied to the rotating shaft.

Abstract: A shaft coupling arrangement and a corresponding method for coupling shafts are disclosed herein. The shaft coupling arrangement includes an input shaft operable to rotate about a first axis. The shaft coupling arrangement also includes an output shaft operable to rotate about a second axis. The shaft coupling arrangement also includes a gearing arrangement operable to engage the input and output shafts together for rotation in the same angular direction at different angular speeds. In one embodiment of the invention, the gearing arrangement includes a plurality of nested bevel gears. In another embodiment of the invention, the gearing arrangement can include a single layshaft.

Abstract: An inner rotor shaft for use in a small twin spool gas turbine engine, the inner rotor shaft having a hollow middle section formed of a smaller diameter hollow section on a compressor end and a larger diameter hollow section on the turbine end of the shaft. Solid shaft end extend from the hollow section to form a forward solid shaft end to secure the fan rotor disk and an aft solid shaft end to secure the turbine rotor disk. A parabolic shaped transition section joins the forward shaft end to the smaller diameter hollow section, and a conical shaped transition section joins the aft shaft end to the larger diameter hollow section. A conical shaped transition piece joins the two hollow sections together to form an inner rotor shaft that can fit within a minimal space between the compressor rotor disk and the annular combustor assembly of the engine.

Abstract: A centrifugal supercharger includes a case presenting a compressor chamber and a transmission chamber. An impeller in the compressor chamber is mounted to a shaft that extends into the transmission chamber. The impeller shaft is drivingly connected to a power input shaft by intermeshing gears provided on the shafts. A portion of the transmission chamber defines a fluid reservoir in which lubrication fluid is held. The intermeshing gears, as well as the bearing assemblies supporting the shafts, are located outside the fluid reservoir portion of the transmission chamber. A rotatable fluid-propelling element partly submerged in the lubrication fluid contained within the reservoir portion ensures that sufficient but not excessive lubrication fluid is supplied to the intermeshing gears and the bearing assemblies. A dedicated lubricant reserve system ensures that the required operating level of fluid is provided to, and maintained in, the reservoir portion.

Abstract: A method for engaging a drive shaft of a turbo engine with an output shaft by means of a clutch is provided. The turbo engine is run up to a rotational speed that is subsynchronous to the speed of the output shaft and is maintained at the steady speed before a signal is set or before starting the engagement process.

Abstract: A machine train includes a drive unit, preferably a steam turbine with axial exhaust flow, a geared turbine machine, and an additional compressor. The geared turbine machine has an integrated gear train with a drive pinion for driving turbine machine rotors via a large gear, and an output pinion of a rotational speed reduction power gear for driving the additional compressor.

Abstract: An assembly for a gas turbine engine includes an intermediate case and a gearbox. The intermediate case defines an annular transition duct. The gearbox comprises a plurality of lobes and is integrally formed with the annular transition duct.

Abstract: A casing provided centrally with a sealed structure chamber. Small-sized separate four filter elements are arranged each on opposite sides of the chamber such that inflow air from a suction section into the casing is introduced via the filter elements into the chamber. Each filter element is detachably fitted over a filter-element mount having openings at its outer periphery. Upon filter-element replacement, the filter elements are replaced individually by opening a window. An integral cast casing having compressing sections and compressed air passages integrally fabricated therewith by casting is formed with receptacles for first and second intercoolers and an aftercooler. The intercoolers and aftercooler are received in the receptacles. Outlets of the intercoolers are connected with suction sides of second- and third-stage compressors through second- and third-stage suction pipes, respectively. A blowoff silencer is arranged between the integral cast casing and an oil tank.

Abstract: Turbomachine such as an aircraft turbojet comprising an electrical generator/starter (26) that can be mounted and dismounted by axial translation in an upstream enclosure (18) of the turbomachine between the low-pressure compressor and the high-pressure compressor, and couple to electrical cables (34) which extend inside the structural arms (12) of the intermediate casing (10) of the turbomachine.

Abstract: A wind power plant is provided having a rotor which is rotatably supported with respect to a rotor axis by a bearing arrangement. A rotor blade is fixed to a rotor hub and extends therefrom radially outwardly, with respect to the rotor axis. The bearing arrangement includes a first bearing ring fixed to a support arrangement in a torque-proof manner and disposed coaxially with respect to the rotor axis, and a second bearing ring being rotatably, with respect to the rotor axis, supported on the first bearing ring and fixed to the rotor hub.

Abstract: The invention provides an assembly for driving accessories of a gas turbine, the assembly comprising: a gearbox having a front side face and a rear side face opposite the front face and having mounted therein a first gear train made up of three toothed wheels meshing with one another, and a second gear train made up of four toothed wheels meshing with one another; a power transmission shaft that is coupled in rotation with the first and second gear trains by means of a toothed wheel pair, and that emerges from the front side face of the gearbox; and nine distinct gas turbine accessories mounted against the side faces of the gearbox, and each including a respective drive shaft that is coupled in rotation with one of the toothed wheels of the two gear trains.

Abstract: Movement system (10) for the inspection of a turbine (40) of the type equipped with a shaft (42) having a series of blades, which is coupled with a shaft (72) of a compressor (70) by means of a loading joint (80), the system (10) comprises a crank rotation mechanism (20) in turn comprising a reducer group (24) for rotating the shaft (42) of the turbine (40) to allow the inspection of the series of blades by means of a boroscope, avoiding the necessity of decoupling the turbine (40) from the compressor (70).

Abstract: An output shaft air/oil separator system comprises an outer housing, an oil passage, a spline shaft having a cavity formed therein that communicates with the oil passage, an output shaft disposed at least partially within the spline shaft cavity that has a first section spaced apart from an inner surface of the spline shaft to form a gap therebetween in communication with the spline shaft cavity and a second section contacting at least a portion of the spline shaft inner surface, a housing cavity defined by at least a portion of an outer surface of the spline shaft and the outer housing, an annular groove formed in the spline shaft communicating with the spline shaft cavity, and at least one port extending between the spline shaft inner and outer surfaces in communication with the annular groove and the housing cavity.

Abstract: Gas turbine engine systems involving tip fans are provided. In this regard, a representative gas turbine engine system includes: a multi-stage fan having a first rotatable set of blades and a second counter-rotatable set of blades, the first rotatable set of blades defining an inner fan and a tip fan; and an epicyclic differential gear assembly operative to receive a torque input and differentially apply the torque input to the first set of blades and the second set of blades.

Abstract: A gas turbine engine including a gas generator module and a reduction gearbox module. The gas generator module has an axis which extends longitudinally along a centreline of the gas generator module, and the reduction gearbox module has an axis which extending longitudinally along the centreline of the reduction gearbox and is offset from said generator axis. The reduction gearbox is driven by an intermediate shaft angled relative to the turbine output shaft.

Abstract: A gas turbine engine (10) provides a differential gear system (58) coupling the turbine (20) to the bypass fan (14) and the compressor (16). In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear (74), which drives a planet carrier (78) and a ring gear (80) in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

Abstract: A wind power generating device includes a housing, a transmission unit, at least one winding disc, at least one magnetic disc, and a rotating unit. When there are a plurality of winding discs and a plurality of magnetic discs, the winding discs and the magnetic discs are axially spaced and alternately arranged in the housing behind the transmission unit. When the magnetic discs are directly rotated by the rotating unit and the winding discs are indirectly rotated by the rotating unit via the transmission unit, magnetic bodies on the magnetic discs and windings on the winding discs are quickly moved in a relative motion to produce relatively large flux change, enabling the wind power generating device to have increased power generation capacity.

Abstract: A keyless coupling assembly for connecting concentric shafting components in a sealless pump comprises a first shafting member, a second shafting member and a plurality of torque strips. The first shafting member comprises an annular body and an inner surface disposed within the annular body. The second shafting member comprises a cylindrical body and an outer surface. The cylindrical body is disposed within the inner surface of the first shafting member. The outer surface encircles the cylindrical body and faces the inner surface. The plurality of torque strips is positioned between the outer surface and the inner surface to form anti-rotation grooves to prevent relative rotation between the first and second shafting members.

Abstract: A gear pump for the dosed conveyance of pigmented lacquers or paints and which is adapted for use with a painting robot. The gear pump comprises two toothed wheels meshing with one another and which are mounted within a pump housing in such a manner that they can be rotated by a driven drive shaft and a fixed bearing shaft. For this, the drive shaft is mounted by a bearing section at multiple points in a pump housing and a coupling section of the drive shaft projects out of the pump drive to connect to a drive. In order, on the one hand, to avoid wear due to high pressure forces and, on the other hand, to absorb a pronounced load from the outside, a supporting bearing for the radial and axial support of the drive shaft is formed on the drive shaft's coupling section projecting outside of the pump housing.

Abstract: The mechanical counter-rotation drive according to the present invention is based on the laws of relative motion of an eccentric part of one of at least two shafts, which are constitutive parts of this drive, with respect to the plates of a determined shape whose motion is confined by pins arranged in a determined arrangement, is illustrated in FIG. 1, where in the housing 10 which supports the mechanical counter-rotation drive are accommodated the first (driving) plate 30 and the second (driven) plate 40 in such a manner that they are approximately or completely parallel to one another. In the housing 10 are embedded a plurality of pins 20 of which each one represents a shaft which bears and around which rotates at least one cylinder 35 which is in operational contact with the perimeter 135 of the first plate 30 which is in rigid contact with the first shaft 50 (which shaft is not visible in FIG. 1).

Abstract: A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Abstract: A system for transferring mechanical torque variably between a plurality of rotating machines in a turbofan engine. Two devices are used, where the first device relies upon magnetic properties of a planetary magnetic gearbox to couple the magnetic machines. The second device is used to variably control the torque transfer between the magnetic machines. The system couples rotating shafts rotating at differing speeds within a turbofan engine for controllably transferring power. To transfer power in the system, a fixed gear ratio is obtained by coupling the relatively high- and low-speed engine shafts to an epicyclic magnetic gearbox.

Abstract: A turbine engine includes an epicyclic gear train that has a two-piece ring gear. Each portion of the ring gear includes radially outwardly extending flanges that are axially constrained to a turbo fan shaft by bolts secured circumferentially along the flanges. Knife edge seals are secured to the flanges to contain oil expelled through the ring gear into a gutter. The ring gear and turbo fan shaft can be rotationally balanced together.

Abstract: A centrifugal supercharger includes a case presenting a compressor chamber and a transmission chamber. An impeller in the compressor chamber is mounted to a shaft that extends into the transmission chamber. The impeller shaft is drivingly connected to a power input shaft by intermeshing gears provided on the shafts. A portion of the transmission chamber defines a fluid reservoir in which lubrication fluid is held. The intermeshing gears, as well as the bearing assemblies supporting the shafts, are located outside the fluid reservoir portion of the transmission chamber. A rotatable fluid-propelling element partly submerged in the lubrication fluid contained within the reservoir portion ensures that sufficient but not excessive lubrication fluid is supplied to the intermeshing gears and the bearing assemblies. A dedicated lubricant reserve system ensures that the required operating level of fluid is provided to, and maintained in, the reservoir portion.

Abstract: A device for the targeted adjustment of the angle of incidence of a rotor blade (13) which is rotatably mounted, at the foot (14) thereof, on a hub (12) of a rotor (11) of a wind power installation (10). The device includes a gearing, a driving toothed wheel (21, 41) that meshes with the gearing (20, 40), and a lubricating device. The lubricating device, due to a temporary displacement of the driving toothed wheel (21, 41) from an operating position into a lubricating position, can be engaged with a defined point of the gearing (20) or the driving toothed wheel (41), respectively previously engaged with the driving toothed wheel (1) or the gearing (20, 40), so as to transfer lubricant.

Abstract: An air turbine starter (ATS) configured to couple to a gearbox, the ATS including an output shaft having an outer peripheral surface, a gearbox section, and an ATS section, the gearbox section configured to be disposed within, and coupled to, the gearbox and the ATS section configured to be disposed within the ATS, and a shield plate extending radially from the outer peripheral surface and coupled to the ATS section of the output shaft.

Abstract: A turbojet includes a differential gear with a first planetary pinion driven by the shaft of the high pressure spool and a second planetary pinion driven by the shaft of the low pressure spool. The planetary pinions drive satellite pinions mounted in a cage by which the ancillary machines are driven. The satellite pinions and said cage are co-rotary and the mechanical transmission ratio R1 between the high pressure shaft and the first planetary pinion of the differential gear and the transmission ratio R2 between the low pressure shaft and the second planetary pinion of the differential gear are such that the power extraction distribution between the high pressure spool and the low pressure spool at idle speed is between 80%/20% and 20%/80%. The operation of the high pressure compressor is not affected by the maximum power drawn by the ancillary machines.

Abstract: A multi-phase centrifugal supercharging system (10) configured for supplying compressed induction fluid to an engine (E) is disclosed. The air induction system (10) broadly includes a drive assembly (12) powered by the engine (E), a supercharging assembly (14) driven by the drive assembly (12) to compress induction fluid, and an induction fluid flow control assembly (16) in communication with the supercharging assembly (14) to control operation of the supercharging assembly (14) and cooperating therewith to deliver the compressed induction fluid to the intake manifold (IM) of the engine (E). The supercharging assembly (14) includes a pair of centrifugal superchargers (28 and 30) that are phased by the control assembly (16) between multiple operating phases, including a series phase (172) and a parallel phase (176). An alternative air system (306) is also disclosed, in use with a pneumatic conveyor (300), that phases between normal series operation and parallel, clog-displacing operation.

Abstract: A multi-phase centrifugal supercharging system (10) configured for supplying compressed induction fluid to an engine (E) is disclosed. The air induction system (10) broadly includes a drive assembly (12) powered by the engine (E), a supercharging assembly (14) driven by the drive assembly (12) to compress induction fluid, and an induction fluid flow control assembly (16) in communication with the supercharging assembly (14) to control operation of the supercharging assembly (14) and cooperating therewith to deliver the compressed induction fluid to the intake manifold (IM) of the engine (E). The supercharging assembly (14) includes a pair of centrifugal superchargers (28 and 30) that are phased by the control assembly (16) between multiple operating phases, including a series phase (172) and a parallel phase (176), to supply constant target boost to the intake (IM) over the entire rev range of the engine (E).

Abstract: A ram air turbine power system includes a ram air turbine having a turbine shaft, turbine blades for rotating the turbine shaft; and an electrical generator or other power source device driven by a power shaft, for providing power. The power shaft has a generally hollow tubular shape, and the turbine shaft extends coaxially within the power shaft. The ram air turbine power system also includes a gearbox housing a planetary gear train, where one end of the gear train is a planetary sun gear spline coupled to the power shaft and the other end of the gear train is a planetary ring gear spline coupled to the turbine shaft so that the rotating turbine shaft drives the power shaft through the gear train increasing the speed of the power shaft over the speed of the turbine shaft.

Abstract: A steam turbine 1 constructed in accordance with the present invention comprises a high-pressure module 2 and a low-pressure module 3, a speed-reducing gearbox 4, and an alternator, and wherein the high-pressure module 2 has a single stage of blades 20. This single stage of blades 20 performs the same function as a multi-stage high-pressure module, but with a blade design that is different from the blade design of multi-stage steam turbines. For example, the pressure ratio between the inlet and the outlet of the high-pressure module 2 may be in the range 3 to 20.

Abstract: An air turbine starter for use in aircraft or other gas turbine engine applications. In a particular embodiment, the air turbine starter has a titanium unitary inlet structure. The unitary inlet structure has a housing having a longitudinal centerline. The housing defines an air inlet, a mounting surface, and a flow path therebetween. Integrally formed inside the housing and transverse to the longitudinal centerline is a stator for directing the flow of air in to the turbine blades of the turbine starter. The stator has a central circular body with a plurality of angularly spaced circumferentially mounted stator fins. An improved unitary inlet structure and method for making such a unitary inlet and stator are also provided.

Abstract: An impeller for a magnetic-drive centrifugal pump includes a core for supporting a magnetic assembly of magnets. An inner barrier covers at least part of the magnets. The inner barrier hermetically isolates the magnetic assembly within the impeller. For example, in one embodiment the inner barrier may be sealed or hermetically connected to the core at one or more seams. An outer barrier overlies the inner barrier.

Abstract: A water turbine includes a casing, a rotor, a primary drive shaft, a speed-reduction gear set, and an output drive unit. The casing confines a water compartment, and is formed with a water inlet for admitting pressurized water into the water compartment, and a water outlet for discharging the pressurized water from the water compartment. The rotor is mounted rotatably in the water compartment, and is driven rotatably by flow of the pressurized water from the water inlet through the water outlet. The primary drive shaft is coupled to and is co-rotatable with the rotor. The speed-reduction gear set is coupled to and is driven rotatably by the primary drive shaft. The output drive unit is coupled to and is driven rotatably by the speed-reduction gear set.