Hybrid Bearing Assembly for Flap Hinge Misalignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bearings used in fixed wing aircraft flap hinge arms face stress and misalignment issues due to the increased curvature of wings, compromising their operation and the positioning of flaps.
Innovation Solution
A hybrid bearing assembly with a concave outer race, rolling elements, and a self-lubricating liner that allows for up to 45 degrees of misalignment and axial sliding, combining the swivel action of spherical bearings with rolling element bearings, and a lubricious liner with varying coefficients of friction for different operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional bearings are used in flap hinge arms, then the structure is simple and easy to manufacture, but the bearing cannot accommodate misalignment caused by increased wing curvature, leading to compromised operation
Solution Approach 1:
The patent combines a spherical plain bearing (outer race with concave contour) and a rolling element bearing (inner race with grooves and rolling elements) into a single hybrid bearing assembly. This merging allows the bearing to accommodate misalignment through the spherical plain bearing portion while providing low-friction rotation through the rolling element portion, resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The outer race is designed with a concave spherical contour that allows the inner race to pivot and accommodate misalignment up to 45 degrees. This spheroidality enables the bearing to adapt to the increased wing curvature and associated misalignment without compromising operation.
2Reliability
If a lubricious liner is added to the inner race, then friction is reduced and durability is improved, but the device complexity increases
Solution Approach 1:
The patent applies a lubricious liner coating to the inner race surface, changing the friction parameter of the bearing. This liner reduces the coefficient of friction between the rolling elements and the inner race, improving durability and reliability while the coating application process integrates smoothly into the manufacturing workflow.
3Adaptability or versatility
If the bearing allows greater misalignment and axial sliding, then the range of motion is enhanced, but the precision and stability may be compromised
Solution Approach 1:
The patent segments the bearing functions into two distinct portions: the spherical plain bearing portion (outer race) that handles misalignment and axial sliding, and the rolling element bearing portion (inner race with rolling elements) that maintains precise rotational positioning. This segmentation allows each portion to optimize its specific function without compromising the other.
Solution Approach 2:
The concave spherical contour of the outer race provides a self-centering effect that maintains precision while allowing misalignment. The curved surface geometry ensures that the inner race remains properly positioned during rotation, preventing excessive runout and maintaining flap positioning precision even as the bearing accommodates up to 45 degrees of misalignment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The hybrid bearing assembly enhances the range of motion and stability, accommodating greater misalignment and reducing friction, thus improving the operation and durability of flap hinge arms under varying loads and conditions.
Implementation Method 1
a lubricious liner having a coefficient of friction of a magnitude sufficient to prevent relative motion between the inner race and a shaft extending through the bore of the inner race during a first operating condition and to allow relative motion between the inner race and the shaft during a second operating condition
Implementation Method 2
the lubricious liner having a modulus of compression of a magnitude sufficient to allow misalignment of the inner liner-surface relative to the exterior liner-surface in response to a force applied thereto
Implementation Method 3
a plurality of rolling elements rollably located in the at least one groove and in rolling contact with the inner surface of the outer race
Data Source
AI summary
A bearing assembly includes an outer race having an inner surface defining a concave contour and an inner race positioned in the outer race. The inner race has an inner surface defining a bore therethrough and an outer surface defining at least one groove circumscribing the outer surface. A plurality of rolling elements is rollably located in the groove and is in rolling contact with the inner surface of the outer race. A lubricious liner has an inner liner-surface and an exterior liner-surface, the exterior liner-surface being disposed on the inner surface defining the bore. The lubricious liner has a modulus of compression of a magnitude sufficient to allow misalignment of the inner liner-surface relative to the exterior liner-surface in response to a force applied thereto.