Aircraft Control Surface Roller Assembly for Reduced Track Wear

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Solution Overview

Problem

Aircraft flap rollers experience excessive wear due to contact with the flap track, leading to maintenance challenges and significant downtime and costs associated with replacement.

Innovation Solution

A roller assembly for aircraft moveable control surfaces featuring a primary roller and a secondary roller with a housing allowing three degrees of rotational freedom, which reduces friction and wear by engaging with different surfaces of the track, including a web surface, thereby minimizing contact and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single roller is used to support the moveable control surface, then the device complexity is reduced, but the roller experiences excessive wear due to contact with multiple surfaces of the track

Engineering Contradiction:
Improveroller assembly complexityVSAvoidroller lifespan
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The roller assembly is divided into two separate rollers: a primary roller that contacts the first surface of the track and a secondary roller that contacts the second surface (web) of the track. This segmentation distributes the wear across two separate rolling elements rather than concentrating it on a single roller, thereby extending the overall lifespan and reliability of the roller assembly while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from a single-point contact configuration to a multi-surface contact configuration by adding the secondary roller that engages with the web surface of the track. This dimensional change in the contact geometry allows the system to distribute loads and wear across different spatial dimensions, improving reliability without significantly increasing complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the roller is designed to contact multiple surfaces of the track, then the roller provides better support and stability, but the friction and wear increase significantly

Engineering Contradiction:
Improveroller stabilityVSAvoidfriction and wear
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

By segmenting the roller function into two separate rollers (primary and secondary), each roller contacts only one specific surface of the track. This segmentation reduces the friction and wear on each individual roller compared to a single roller contacting multiple surfaces, while the combined system maintains excellent stability through the distributed contact points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The roller assembly acts as an intermediary between the moveable control surface and the track structure. The two-roller configuration provides this intermediary function more effectively by distributing the interaction forces across two separate contact points, reducing the harmful friction and wear effects while maintaining system stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the roller assembly includes multiple rollers with degrees of freedom, then the wear on rollers and track is reduced, but the device complexity increases

Engineering Contradiction:
Improveroller and track durabilityVSAvoidroller assembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The roller assembly is segmented into two independent rollers with individual mounting configurations. The primary roller is mounted to rotate about a first axis, while the secondary roller is mounted to rotate about a second axis perpendicular to the first. This segmentation allows each roller to independently handle wear on its respective contact surface, improving durability while keeping the overall assembly complexity manageable through standardized modular components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The roller assembly incorporates dynamic degrees of freedom, allowing the primary roller to rotate about its axis and the secondary roller to rotate about a perpendicular axis. This dynamic configuration enables the rollers to adapt to variations in track geometry and wear patterns, improving durability through self-adjustment while maintaining reasonable structural complexity.

Inventive Principle:
Principle #15Dynamics

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 roller assembly significantly reduces wear and tear on both the rollers and the track, enhancing the lifespan of the components and minimizing maintenance needs, resulting in a more reliable and cost-effective solution for aircraft operations.

Implementation Method 1

The primary roller is coupled to the roller end of the roller shaft and is configured to rotate about the longitudinal shaft axis. The primary roller is configured to engage and roll along a first surface of the track.

Methodology Applied
Scientific EffectRolling contact: Roller

Implementation Method 2

The secondary roller is configured to engage and roll along a second surface of the track

Methodology Applied
Scientific EffectRolling contact: Roller

Implementation Method 3

The housing is movably coupled to the roller end of the roller shaft with three degrees of rotational freedom relative to the roller end of the roller shaft

Methodology Applied
Scientific EffectRotational freedom: Gimbal

Data Source

PatentEP4328132A1Reduced-friction roller and related assembly for a moveable control surface of an aircraft
Publication Date: 2024.02.28 GULFSTREAM AEROSPACE CORP
  • EP4328132A1 patent drawingFigure 1
  • EP4328132A1 patent drawingFigure 2
  • EP4328132A1 patent drawingFigure 3

AI summary

A roller for a control surface of an aircraft includes a roller shaft (202), a primary roller (204) coupled to the shaft (202), and a roller assembly (300) coupled to the shaft (202). The shaft includes a longitudinal axis, a mounting end (214) that couples with a roller fitting of the control surface, and a roller end (216, Fig. 6). The primary roller can rotate about the longitudinal axis, and can engage and roll along a first surface of a track. The roller assembly includes a secondary roller (304) having a longitudinal roller axis and configured to engage and roll along a second surface of the track. The roller assembly also includes a housing (302) that retains the secondary roller while allowing the secondary roller to rotate about the longitudinal roller axis. The housing is movably coupled to the roller end of the roller shaft with three degrees of rotational freedom relative to the roller end of the roller shaft.