Patent Application
20160200430
This invention relates generally to actuation systems, and more particularly, to a tail rotor actuation system.
A rotorcraft may include one or more rotor systems. One example of a rotorcraft rotor system is a main rotor system. A main rotor system may generate aerodynamic lift to support the weight of the rotorcraft in flight and thrust to counteract aerodynamic drag and move the rotorcraft in forward flight. Another example of a rotorcraft rotor system is a tail rotor system. A tail rotor system may generate thrust in the same direction as the main rotor system's rotation to counter the torque effect created by the main rotor system.
Particular embodiments of the present disclosure may provide one or more technical advantages. A technical advantage of one embodiment may include the capability to improve packaging of a tail rotor actuation system. A technical advantage of one embodiment may include the capability to add redundancy to a tail rotor actuation system, especially in a fly-by-wire control system.
Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims included herein.
To provide a more complete understanding of the present invention and the features and advantages thereof, reference is made to the following description taken in conjunction with the accompanying drawings, in which:
Fuselage 130 represents the body of rotorcraft 100 and may be coupled to rotor system 110 such that rotor system 110 and blades 120 may move fuselage 130 through the air. Landing gear 140 supports rotorcraft 100 when rotorcraft 100 is landing and/or when rotorcraft 100 is at rest on the ground. Empennage 150 represents the tail section of the aircraft and features components of a rotor system 110 and blades 120′. Blades 120′ may provide thrust in the same direction as the rotation of blades 120 so as to counter the torque effect created by rotor system 110 and blades 120. Teachings of certain embodiments relating to rotor systems described herein may apply to rotor system 110 and/or other rotor systems, such as other tilt rotor and helicopter rotor systems. It should also be appreciated that teachings regarding rotorcraft 100 may apply to aircraft and vehicles other than rotorcraft, such as airplanes and unmanned aircraft, to name a few examples.
As stated above, a control system may selectively control the pitch of each blade 120 and/or 120′ in order to selectively control direction, thrust, and lift of rotorcraft 100. In some embodiments, a control system may receive inputs (e.g., from a pilot, flight computer, and/or other flight control equipment) and change the pitch of each blade 120 and/or 120′ based on these inputs by, for example, changing the swashplate position. Example embodiments of a control system for selectively controlling the pitch of blades 120 and/or 120′ may include equipment from mechanical, fly-by-wire, and/or other flight control systems.
Different control systems may offer different benefits. For example, some control systems may include redundant components to improve safety and operation in the event of a failure. As another example, some control systems may have smaller packaging sizes or include components that can be moved to more convenient areas of rotorcraft 100. As yet another example, some control system components may work with fly-by-wire flight control systems, which may offer lower weight and greater controllability as compared to mechanical flight control systems.
Teachings of certain embodiments recognize the capability to provide some or all of these benefits. For example,
As seen in the example of
In the example of
In some embodiments, actuator assembly 210 may include a manifold associated with each actuator 210a-210c. Each manifold may be in hydraulic communication with a hydraulic power pack to provide hydraulic fluid to the actuators. Each hydraulic power pack may include a pump and a reservoir in one package. One or more flight control computers (FCCs) may control each manifold and/or hydraulic power pack.
In some embodiments, each manifold may include an integrated three function valve (ITFV) configured to allow actuator assembly 210 a to operate even after a failure of one or two of actuators 210a-210c. For example, ITFV may be used to quickly inert a malfunctioning actuator so that the remaining healthy actuators can continue to operate without fighting the malfunctioning actuator. Further, ITFV may allow a single actuator to be in bypass while allowing actuator assembly 210 to be supplied energy via other hydraulic power packs. Each manifold may also include an electro-hydraulic servo-valve (EHSV). An ITFV and EHSV are disclosed in U.S. Pat. No. 7,003,949, titled “Integrated Three Function Valve,” issued 28 Feb. 2006, to Fenny, et al. (Fenny '949). Fenny '949 is incorporated herein by reference.
As seen in the example of
During operation, according to one example embodiment, gearbox 152 provides rotational energy to a rotating mast portion 240a of mast 240. Mast portion 240a transfers at least some of this rotational energy to hub 248, which causes each blade 120′ to rotate. In the example of
Also during operation, according to this example embodiment, actuator assembly 210 extends and retracts yoke 220, which causes control rod 230 to translate linearly. Linear translation of control rod 230 causes extension and retraction of cross-head 242, which is coupled to control rod 230 via roller bearing 244. In the example of
A pitch link 246 couples cross-head 242 to hub 248 and/or blade 120′. In some embodiments, a pitch link 246 may be provided for each blade 120′, although teachings of certain embodiments recognize that more or fewer pitch links may be used. In operation, extension of retraction of cross-head 242 may cause pitch link 246 to change the deflection angle of blade 120′.
Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order.
Although several embodiments have been illustrated and described in detail, it will be recognized that substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the appended claims.
To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims to invoke paragraph 6 of 35 U.S.C. §112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.
