Aircraft Door Hinge Assembly with Programmable Gear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aircraft door hinge assemblies are bulky and occupy significant space within the fuselage, limiting availability for other purposes such as stowage or seating, due to their mechanical linkages that control the door's orientation during opening.
Innovation Solution
A low-profile hinge assembly with a programmable gear assembly that includes a fuselage gear, door gear, and a rack, allowing the door to maintain a parallel orientation relative to the fuselage longitudinal axis during opening, and an emergency power assist assembly to facilitate door opening in emergencies while controlling the hinge arm's motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a mechanical linkage is used to control door orientation during opening, then the door can maintain parallel orientation to the fuselage, but the hinge assembly becomes bulky and occupies significant space within the fuselage
Solution Approach 1:
The patent replaces the conventional bulky mechanical linkage system with an electro-hydraulic actuator system. The actuator uses hydraulic fluid under pressure to control door orientation, eliminating the need for complex mechanical linkages. This substitution reduces the hinge assembly volume while maintaining the ability to control door orientation during opening operations
Solution Approach 2:
The patent employs a hydraulic actuator that uses pressurized hydraulic fluid to control the door's rotational movement. The hydraulic system provides precise control of door orientation with a compact structure, replacing the space-consuming mechanical linkage while maintaining operational control throughout the door opening sequence
2Ease of operation
If a mechanical linkage extends into the fuselage interior to control door orientation, then the door can be maneuvered properly, but the space available for other purposes such as stowage or seating is reduced
Solution Approach 1:
The patent replaces the space-extending mechanical linkage with a compact electro-hydraulic actuator mounted within the hinge assembly. This actuator controls door orientation through hydraulic pressure without requiring extensive mechanical linkages to extend into the fuselage interior, thereby preserving valuable interior space for stowage, seating, or other purposes
3Reliability
If a bulky mechanical linkage is used in the hinge assembly, then the door can be securely controlled, but the hinge assembly occupies significant space that limits availability for other components
Solution Approach 1:
The patent substitutes the bulky mechanical linkage with a compact electro-hydraulic actuator system that maintains secure door control through hydraulic pressure and electronic control. This replacement achieves the same reliability in door control while significantly reducing the volume occupied by the hinge assembly, allowing more space for other aircraft components
Solution Approach 2:
The patent changes the operational parameter from mechanical force transmission through linkages to hydraulic pressure control. This parameter change enables the same door control function to be achieved with a much more compact actuator, reducing hinge assembly volume while maintaining control security through the incompressible nature of hydraulic fluid
Data Source
AI summary
A hinge assembly for connecting a door to a fuselage of an aircraft includes a hinge arm having a fuselage fitting pivotably coupled to a fuselage rotatable interface and a door fitting pivotably coupled to a door rotatable interface. The hinge assembly includes a programmable gear assembly coupled to the hinge arm allowing the hinge arm to pivot around the fuselage fitting when the door is moved from a door closed position to a door open position and causing the door to maintain in a generally parallel orientation relative to the fuselage between the door closed position to the door open position. The programmable gear assembly includes a fuselage gear coupled to the fuselage fitting, a door gear coupled to the door fitting, and a rack operably coupled between the fuselage gear and the door gear.