Helicopter Rotor Blade Control Rod With Adjustable Rotation Stops

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Solution Overview

Problem

Existing control rod systems for adjusting helicopter rotor blades are prone to heavy loading of stops under external forces during flight, which can lead to inefficiencies and potential damage.

Innovation Solution

The control rod system allows for adjustable stop elements that can be displaced circumferentially to change the adjustment range, reducing the forces on stops by enabling a larger or smaller pivoting range through the use of threaded bolts or stop rings, which can be fixed or adjusted to alter the rotation limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the control rod uses fixed stop elements to limit the adjustment range, then the structural simplicity is maintained, but the stops are heavily loaded by external forces during flight

Engineering Contradiction:
Improveforce on stop elementsVSAvoidadjustment range flexibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The stop elements are made adjustable and displaceable in the circumferential direction, transforming from fixed static components to dynamic components that can change position. This allows the adjustment range to be modified while distributing forces more effectively, reducing peak loads on individual stop elements during flight operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The position of stop elements can be changed by displacing them circumferentially, altering the geometric parameters of the control system. This enables optimization of the adjustment range to match actual operational requirements, thereby reducing unnecessary forces on the stops while maintaining structural integrity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the control rod allows in-flight adjustment of rotor blades, then vibration reduction is achieved, but the stops are subjected to heavy loading from spindle drive forces

Engineering Contradiction:
Improvevibration reduction capabilityVSAvoidforce on stops from spindle drive
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The stop elements are designed to be displaceable rather than fixed, allowing them to dynamically adjust their position during operation. This dynamic capability enables the system to accommodate spindle drive forces more effectively while maintaining vibration reduction benefits during in-flight rotor blade adjustment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control rod is divided into adjustable segments with movable stop elements that can be independently positioned. This segmentation allows the stop elements to be optimally placed to minimize force transmission while still providing the necessary adjustment range for vibration control during flight.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the stop elements are made displaceable in the circumferential direction to reduce forces, then the adjustment range flexibility is improved, but the device complexity increases

Engineering Contradiction:
Improveadjustment range variabilityVSAvoidstop element mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The stop elements are made displaceable in the circumferential direction, allowing the adjustment range parameters to be changed without fundamentally redesigning the entire control rod mechanism. This approach provides flexibility while keeping the structural changes relatively simple and focused.

Inventive Principle:
Principle #35Parameter changes

4Force

If the control rod uses a larger pivoting range to reduce forces on stops, then the force distribution is improved, but the precision of blade adjustment may be reduced

Engineering Contradiction:
Improveforce distribution on stopsVSAvoidblade adjustment precision
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The displaceable stop elements enable dynamic optimization of the pivoting range. The system can adjust the range to balance force distribution and adjustment precision requirements for different operational conditions, allowing both large-range force reduction and precise positioning when needed.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3322641B1Control bar for adjusting a rotor blade of a helicopter
Publication Date: 2023.01.04 AIRBUS HELICOPTERS TECH GMBH
  • EP3322641B1 patent drawingFigure 1
  • EP3322641B1 patent drawingFigure 2
  • EP3322641B1 patent drawingFigure 3

AI summary

The invention relates to a control rod (1) for adjusting a rotor blade of a helicopter. Said control rod (1) can be longitudinally adjusted and comprises: at least one contact region element (15), and at least one stop element (8, 9) that is designed to limit, in cooperation with the at least one contact region element (15), the longitudinal adjustability of the control rod (1) to an adjustment range which can be predetermined. The control rod is characterized in that at least one contact region element (15) is arranged such that it can be rotated about the longitudinal axis of the control rod (1), and in that the adjustability is limited by the at least one contact region element (15) coming to rest against the at least one stop element (8, 9) in the circumferential direction of the control rod (1).