Patent Application
20130181448
Generally, the present invention is directed to emergency aircraft systems, and more particularly, exemplary embodiments of the present invention are directed to electrical actuators for mechanically actuating emergency aircraft power systems.
Conventionally, aircraft rely on a ram air turbine (RAT) to provide essential electrical and/or hydraulic power to the aircraft in emergency situations such that power to vital aircraft systems may be adequately maintained. Furthermore, hydraulic actuators are typically used to deploy the RAT outside of an aircraft in these situations. The hydraulic actuators, relying on compressed spring forces and a hydraulic circuit or circuits, may push a RAT into a deployed position in response to an emergency signal or operator request. The hydraulic actuators may be relatively complex allowing for redundant safeties, and therefore may have multiple wet seals, grommets, hoses, and other components subject to mechanical stresses or wear during flight and which are prone to leakage.
According to an exemplary embodiment of the present invention, an electric actuation system for a emergency power system of an aircraft includes a motor control portion, a motor in electrical communication with the motor control portion, mechanical gearing in mechanical communication with the motor, the mechanical gearing configured to translate rotational motion of the motor into linear motion across at least one axis, and an extension member in mechanical communication with the mechanical gearing, the extension member configured to linearly travel across the at least one axis.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
According to exemplary embodiments of the present invention, an actuation system for emergency aircraft power systems is provided with reduced weight and complexity as compared to conventional systems. The technical effects of one or more of embodiments disclosed herein include eliminating potential for hydraulic leakage, an overall reduced weight of aircraft as well as reduced maintenance tasks and simplifying actuator installation by eliminating hydraulic line connections.
Turning to
As illustrated, the hydraulic actuator 200 includes two deployment solenoids 201, a pressure valve 202, a retract solenoid 203, a mounting member 204 that remains fixed to an aircraft structure or the RAT frame, a RAT mounting member 205 that moves as the RAT deploys, a hydraulic cylinder 206, a main tension spring 207, and a plurality of hydraulic interface nubs 208. Generally, the hydraulic actuator 200 is substantially similar to hydraulic actuator 100, for example, in that it generally requires connection to the main aircraft hydraulic system to provide fluid to nubs 208 and electric control signals to solenoids 201, 202, and 203. Furthermore, the main compression spring 207 provides constant mechanical forces along an axis of travel of the hydraulic cylinder 206 to aid in overcoming initial forces required to deploy the RAT.
However, as illustrated in
In contrast, exemplary embodiments of the present invention provide electrically actuated emergency aircraft power systems, such as RATs, such that overall weight is reduced (e.g., no hydraulic circuits or mechanical lock are necessary) and less maintenance is required (e.g., no hydraulic leakage inherent in electrical systems).
For example,
As further illustrated, the system 300 includes backup portion/electric potential 303. As the VDC BUS may be powered by primary aircraft batteries, it may retain some electrical potential with which to drive the motor 302 and brake 307 even during an emergency situation requiring deployment of an emergency aircraft power system such as a RAT. It shall be understood that such an emergency can occur when electrical power is no longer capable of being generated based on motion of the turbine engines of the aircraft, for example. However, under some circumstances, it may beneficial to have an additional source of electric potential. Therefore, the backup portion 303 may include componentry configured to store a suitable electric potential (e.g., transferred from VDC BUS) with which to drive motor 302 in the event of an emergency. Suitable componentry may include a capacitor bank or a battery system.
Turning back to
According to at least one exemplary embodiment of the present invention, an appropriate mechanical gearing 304 and motor 302 with brake 307 and resolver 308 are included in actuator 400 illustrated in
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
