Yaw control system for an air vehicle

Claim 2

An air vehicle including a pair of coaxially mounted contrarotating rotors and a yaw control system for said air vehicle, said yaw control system comprising a first rotational element drivingly connected to one of said two rotors, a second rotational element drivingly connected to the other of said two rotors, a differential gearbox having first and second rotational outputs projecting from opposite sides thereof respectively drivingly connected to said first rotational element and to said second rotational element, input means to drive said differential gearbox, and clutch means connected in parallel with said differential gearbox to said first and second rotational elements and constructed and arranged to transfer a variable amount of torque between the latter whereby to vary the relative amounts of torque delivered to said coaxially mounted contrarotating rotors and exerted by the latter on the air vehicle to effect the yaw control thereof.

Claim 3

The invention according to claim 1 wherein the said clutch means to vary the relative amounts of torque delivered to the coaxially mounted rotors includes a variable clutch arranged to transfer varying amounts of torque therethrough and control means for controllably actuating the variable clutch to effect said yaw control of the air vehicle.

Claim 4

The invention according to claim 2, wherein said variable clutch is a magnetic clutch including a field coil therein and wherein said control means comprises means for passing Controlled amounts of electric current through said field coil to effect controlled variation of the torque transmitted through the variable clutch.

Claim 5

An air vehicle having a yaw control system as defined in claim 1, wherein said first rotational element is a first idler gear in meshing engagement with a first ring gear fixed to said one rotor, said second rotational element is a second idler gear, a second ring gear is fixed to said other rotor and a third idler gear is positioned in meshing engagement with said second idler gear and said second ring gear to reverse the direction of rotation of said other rotor relative to said second idler gear.

Claim 6

An air vehicle including a yaw control system as defined in claim 4, wherein said first idler gear and said second idler gear are positioned in spaced parallel planes and said differential is drivingly connected to said first and second idler gears such as to drive the latter in the same angular direction as seen from one side of said spaced parallel planes.

Claim 7

An air vehicle including a yaw control system as defined in claim 5, wherein said differential has a first output shaft and a second output shaft, a first pinion gear is fixedly mounted on said first output shaft in meshing engagement with said first idler gear, and a second pinion gear is fixedly mounted on said second output shaft, in meshing engagement with said second idler gear.

Claim 8

An air vehicle including a yaw control system as defined in claim 6, wherein said differential is located intermediate said spaced parallel planes and said first pinion gear and said second pinion gear are respectively located in the planes of said first and second idler gears.

Claim 9

The invention as defined in claim 2, wherein said variable clutch includes a first and a second shafts secured to said first and second rotational elements respectively for rotation therewith.

Claim 10

An air vehicle including a yaw control system as defined in claim 8, wherein said first rotational element is fixedly mounted on said first shaft for rotation therewith and said second rotational element is fixedly mounted on said second shaft for rotation therewith.

Claim 11

An air vehicle including a yaw control system as defined in claim 9, wherein said first and second shafts are substantially aligned on opposite sides of said variable clutch mechanism whereby said first and second rotational elements are mounted in spaced apart relationship on opposite sides of said variable clutch mechanism.

Claim 12

An air vehicle including a yaw control system as defined in claim 8, wherein said first rotational element is fixedly mounted on said first shaft for rotation therewith, a pinion gear is fixedly mounted on said input means for rotation therewith, an input gear is fixedly mounted on said second shaft for rotation therewith, said pinion gear meshing with said input gear to rotate said second shaft.

Claim 13

The invention as defined in claim 2, wherein said variable clutch includes a first and a second shafts secured to said first rotational element and connected to said input respectively for rotation therewith and arranged to transfer controlled amounts of torque between said first rotational element and said input to said differential gearbox.

Claim 14

The invention according to claim 2, wherein said first and second rotational elements and said first and second rotational outputs are constructed and arranged to produce a different speed of rotation of said first rotational element relative to said second rotational element.

Claim 15

In an air vehicle provided with a pair of coaxially mounted and axially spaced apart contrarotating rotors, a yaw control system comprising a first ring gear fixedly attached to one rotor concentric thereto, a second ring gear fixedly attached to the other rotor concentric thereto, a differential positioned intermediate said ring gears and having a first output shaft and a second output shaft projecting from opposite sides thereof and a rotational input element, a fiRst pinion gear fixed to said first output shaft for rotation therewith, a second pinion gear fixed to said second output shaft for rotation therewith, a first idler gear mounted in meshing engagement with said first pinion gear and said first ring gear, a second and a third idler gears mounted in meshing engagement with each other and with said second pinion gear and said second ring gear respectively, a variable clutch mechanism having a first rotational element operatively connected to said first idler gear for rotation therewith, and control means adapted to actuate said variable clutch mechanism to change the rotational speed of said first idler gear such as to vary the net torque produced on the air vehicle by the two contrarotating rotors.

Claim 16

In an air vehicle provided with a pair of coaxially mounted and axially spaced apart contrarotating rotors, a yaw control system comprising a first ring gear fixedly attached to one rotor concentric thereto, a second ring gear fixedly attached to the other rotor concentric thereto, a differential positioned intermediate said ring gears and having a first output shaft and a second output shaft projecting from opposite sides thereof and a rotational input element, a fiRst pinion gear fixed to said first output shaft for rotation therewith, a second pinion gear fixed to said second output shaft for rotation therewith, a first idler gear mounted in meshing engagement with said first pinion gear and said first ring gear, a second and a third idler gears mounted in meshing engagement with each other and with said second pinion gear and said second ring gear respectively, a variable clutch mechanism having a first rotational element operatively connected to said first idler gear for rotation therewith, and control means adapted to actuate said variable clutch mechanism to change the rotational speed of said first idler gear such as to vary the net torque produced on the air vehicle by the two contrarotating rotors.

Claim 17

An air vehicle as defined in claim 14, wherein the gear ratios between said first idler gear and said first pinion gear and between said second idler gear and said second pinion gear are selected to cause the first idler gear to rotate at a higher angular speed than the second idler gear.