Forward Folding Rotor Blade Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

There is a need for forward folding rotor blades in aircraft design, as existing backward folding rotor blades may not be suitable for all aircraft configurations, and current solutions do not adequately address the requirements for efficient rotor blade folding and deployment in various flight modes.

Innovation Solution

A rotor blade rotation system that includes two or more rotor blades pivotable about an axis of rotation, a bearing plate with a rotating and non-rotating portion, a fold linkage coupled to the rotating portion, and an actuator that repositions the bearing plate to pivot the rotor blades from a deployed position to a forward folded position, eliminating the need for gearbox and drive train components and allowing for efficient conversion between vertical takeoff and landing and airplane modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If rotor blades are designed to fold forward, then the aircraft can achieve compact storage and reduced drag, but the mechanism complexity increases

Engineering Contradiction:
Improverotor blade storage volumeVSAvoidfolding mechanism complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The folding mechanism is divided into discrete components including fold linkages, actuators, and bearing plates that can independently move and position the rotor blades. This segmentation allows for controlled folding motion while simplifying the overall mechanism design and maintenance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses dynamic actuators that can actively control the position of rotor blades between deployed and folded states. The bearing plates rotate to different positions, enabling the mechanism to adapt its configuration based on operational requirements, thus managing complexity through controlled dynamics rather than fixed mechanical constraints.

Inventive Principle:
Principle #15Dynamics

2Weight of moving object

If rotor blades are folded forward, then weight and drag are reduced, but the reliability of blade deployment may deteriorate

Engineering Contradiction:
Improverotor blade system weightVSAvoidblade deployment reliability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The actuator system incorporates feedback mechanisms to monitor and control the position of bearing plates and fold linkages. This ensures that rotor blades are correctly positioned and locked in both deployed and folded states, maintaining deployment reliability while enabling weight reduction through the folding capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The folding mechanism is designed to automatically position and secure the rotor blades through the actuator-driven rotation of bearing plates. The system self-regulates the folding and deployment process, reducing the need for complex manual intervention systems and maintaining reliability through automated control.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a bearing plate with rotating and non-rotating portions is used, then the actuator can effectively reposition the rotor blades, but the device complexity increases

Engineering Contradiction:
Improverotor blade repositioning easeVSAvoidbearing plate structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The bearing plate is designed with both rotating and non-rotating portions that serve multiple functions: the rotating portion enables fold linkage movement for blade positioning, while the non-rotating portion provides a stable mounting surface for the actuator. This multi-functionality consolidates several operations into a single component, improving ease of operation without proportionally increasing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3243745B1Forward folding rotor blades
Publication Date: 2019.07.10 BELL HELICOPTER TEXTRON INC
  • EP3243745B1 patent drawingFigure 1A
  • EP3243745B1 patent drawingFigure 1B
  • EP3243745B1 patent drawingFigure 1C

AI summary

An aircraft (100) comprising a plurality of engines (132) including two or more rotor blades (202), each rotor blade (202) in mechanical communication with a hub (304) and pivotable about an axis of rotation, a bearing plate (308) comprising a rotating portion (308a) and a non-rotating portion (308b), a fold linkage (306) coupled to the rotating portion (308a) of the bearing plate (308) and in mechanical communication with the rotor blade (202), and an actuator (310) coupled to the non-rotating portion (308b) of the bearing plate (308) and operable to reposition the bearing plate (308) from a first position (312) to a second position (314) such that the folding links (306) pivot the rotor blades (202) from a deployed position to a forward folded position.