Composite Swashplate Guide for Rotorcraft Thermal Stability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional swashplate assemblies in rotary wing aircraft face challenges in maintaining a constant fit and resisting thermal fluctuations and corrosive environments, which can lead to mechanical issues and reduced performance.

Innovation Solution

A swashplate guide formed from composite materials, such as fiberglass-epoxy or graphite-epoxy, with a hollow cylindrical design and a spherical bearing system, where the coefficient of thermal expansion is optimized to ensure a constant fit and a flange interface for additional structural support, and optionally coated for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional materials (metal) are used for the swashplate guide, then structural strength is sufficient, but resistance to thermal fluctuations and corrosive environments deteriorates

Engineering Contradiction:

Improveresistance to thermal fluctuations and corrosive environmentsVSAvoidthermal fluctuations and corrosive environments

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies composite materials (specifically carbon fiber reinforced polymer or CFRP) to fabricate the swashplate guide tube. This composite material provides superior resistance to thermal fluctuations and corrosive environments compared to conventional metals, while maintaining the required structural strength. The composite construction eliminates corrosion issues and provides stable thermal expansion characteristics.

Inventive Principle:

Principle #40Composite materials

2Weight of moving object

If conventional metal materials are used for the swashplate guide, then manufacturing simplicity is maintained, but weight increases

Engineering Contradiction:

Improveweight of swashplate guideVSAvoidmanufacturing complexity of composite structure

Core Design Contradiction:

Weight of moving objectVSEase of manufacture

Solution Approach 1:

The swashplate guide tube is constructed using composite materials (CFRP) which significantly reduce weight compared to conventional metal materials. The composite construction method, while requiring specialized manufacturing processes, enables the creation of a lightweight yet structurally sound component that meets all performance requirements.

Inventive Principle:

Principle #40Composite materials

3Stability of the object's composition

If a tight fit is used between the swashplate guide and spherical bearing, then mechanical stability is improved, but thermal expansion mismatch causes fit inconsistency

Engineering Contradiction:

Improvemechanical fit stabilityVSAvoidthermal expansion variation

Core Design Contradiction:

Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent addresses thermal expansion mismatch by carefully selecting composite materials with thermal expansion coefficients matched to the spherical bearing material. This ensures that temperature variations do not cause differential expansion or contraction, maintaining a consistent fit between the swashplate guide and bearing throughout operational temperature ranges.

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The composite material construction of the swashplate guide provides controlled thermal expansion characteristics that can be tailored to match the spherical bearing material, ensuring consistent mechanical fit stability across varying temperature conditions.

Inventive Principle:

Principle #40Composite materials

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 solution provides improved resistance to thermal fluctuations and corrosive environments, maintaining a consistent mechanical fit and reducing weight, thereby enhancing the reliability and efficiency of rotor pitch control systems.

Implementation Method 1

The hollow cylindrical tube has a coefficient of thermal expansion such that a constant fit is generated between the swashplate guide and the spherical bearing

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

A bearing system allows the rotational swashplate to rotate relative to the rotationally stationary swashplate

Methodology Applied

Scientific EffectSpherical bearing mechanism: Ball Bearing

Data Source

PatentUS10442532B2Composite swashplate guide for rotorcraft control systems

Publication Date: 2019.10.15 SIKORSKY AIRCRAFT CORP

AI summary

A swashplate guide for use with a spherical bearing and which connects with an adjacent component includes a hollow cylindrical tube formed from a composite material. An exterior surface of the hollow cylindrical tube provides an engagement surface with the spherical bearing. A flange arranged at an end of the hollow cylindrical tube provides an interface with the adjacent component.