Aircraft Pitch Control via External Drive Element

Solution Overview

Problem

The existing pitch control systems in aircraft require a larger and heavier gearbox housing to accommodate actuation units, which increases weight and reduces efficiency.

Innovation Solution

An aircraft pitch control apparatus with a drive element coupled to the exterior of the gearbox housing, utilizing an annular electro-mechanical actuator to convert rotational energy into axial movement of pitch control rods, allowing for controlled pitching of propeller blades without the need for a bulky gearbox housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the actuation unit is provided as part of the gearbox housing, then the pitch control function is integrated, but the gearbox housing size and weight increase

Engineering Contradiction:

Improvepitch control function integrationVSAvoidgearbox housing weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The pitch control apparatus is segmented into separate components: the drive element is positioned on the exterior of the gearbox housing rather than being integrated within it. This allows the gearbox housing to maintain its original size and weight while the pitch control function is still achieved through the externally mounted drive element that engages with the propeller pitch mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The drive element is relocated from the internal three-dimensional space of the gearbox housing to the external surface of the housing. This dimensional relocation allows the pitch control mechanism to operate outside the constrained internal volume of the gearbox, eliminating the need to increase housing size while maintaining full pitch control functionality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the actuation unit is provided as part of the gearbox housing, then the pitch control function is integrated, but the gearbox housing volume increases

Engineering Contradiction:

Improvepitch control function integrationVSAvoidgearbox housing volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The pitch control apparatus is segmented into separate components: the drive element is positioned on the exterior of the gearbox housing rather than being integrated within it. This allows the gearbox housing to maintain its original size and weight while the pitch control function is still achieved through the externally mounted drive element that engages with the propeller pitch mechanism.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The drive element is relocated from the internal three-dimensional space of the gearbox housing to the external surface of the housing. This dimensional relocation allows the pitch control mechanism to operate outside the constrained internal volume of the gearbox, eliminating the need to increase housing size while maintaining full pitch control functionality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

This configuration reduces the size and weight of the gearbox housing while maintaining effective pitch control, enhancing aircraft efficiency and maneuverability.

Implementation Method 1

an annular electro-mechanical actuator (EMA) configured to convert rotational energy generated by the drive element to thereby control a pitching of propeller blades

Methodology Applied

Scientific EffectElectro-mechanical conversion:

Data Source

PatentUS10173767B2Aircraft with drive element coupled to gearbox housing exterior

Publication Date: 2019.01.08 SIKORSKY AIRCRAFT CORP

AI summary

An aircraft is provided and includes a gearbox housing through which a drive shaft configured to drive propeller rotation extends and a pitch control apparatus. The pitch control apparatus includes a drive element coupled to an exterior of the gearbox housing and an annular electro-mechanical actuator (EMA) configured to convert rotational energy generated by the drive element to thereby control a pitching of propeller blades about corresponding pitch axes.