Flexible Rod SCAS Actuator for Helicopter Lateral Displacement

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional Stability and Control Augmentation Systems (SCAS) for helicopters face challenges in accommodating non-linear movements of rotor actuators, leading to potential instability and reduced reliability due to the inability to effectively handle lateral or angular displacements without transferring side loads.

Innovation Solution

The introduction of a SCAS module with flexible rods or quills that deform to accommodate angular and lateral movements, allowing the SCAS actuators to remain connected and operational during such displacements, thereby enhancing the system's ability to handle non-linear movements without compromising the linear output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional SCAS actuator is used with a rigid piston rod, then the actuator can provide stable linear output, but it cannot accommodate lateral or angular displacements without transferring side loads

Engineering Contradiction:

Improveability to accommodate lateral and angular displacementsVSAvoidstability and control reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies a flexible membrane or thin film structure to the piston rod, allowing it to bend and deform laterally while maintaining its primary linear motion function. This flexible element accommodates angular and lateral displacements without transferring harmful side loads to the actuator mechanism, thereby improving adaptability while maintaining reliability

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the physical parameter of the piston rod from rigid to flexible, enabling it to dynamically adapt its shape during operation. This parameter change allows the rod to accommodate varying displacement conditions (lateral, angular, and linear) while maintaining system stability through controlled flexibility

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the SCAS actuator uses a rigid connection to the movable element, then the linear output is precise, but the actuator cannot follow non-linear movements of the rotor

Engineering Contradiction:

Improveability to follow non-linear rotor movementsVSAvoidlinear output precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The flexible membrane structure allows the connection between the actuator and movable element to accommodate non-linear rotor movements while maintaining precise linear output control. The flexibility enables following of angular and lateral displacements without compromising the precision of the primary linear actuation function

Inventive Principle:

Principle #30Flexible shells and thin films

3Adaptability or versatility

If the piston rod is made flexible to accommodate lateral movements, then side loads are avoided, but the structural strength may be reduced

Engineering Contradiction:

Improveability to accommodate lateral displacementsVSAvoidpiston rod strength

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The flexible membrane is designed with sufficient strength to accommodate lateral displacements while maintaining load-bearing capacity for the primary linear actuation. The thin film structure provides the necessary flexibility to avoid side loads while retaining adequate structural strength through optimized material selection and geometric design

Inventive Principle:

Principle #30Flexible shells and thin films

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 design improves the reliability and safety of the SCAS by allowing the actuators to follow lateral movements without transferring side loads, thus maintaining stability and control during various flight conditions, including misalignment and failure scenarios.

Implementation Method 1

the flexible rod or quill is configured for deforming into the space to accommodate displacement of the first movable element

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS10836469B2Integrated stability and control augmentation system

Publication Date: 2020.11.17 MICROTECHNICA SRL

AI summary

A SCAS module includes one or more SCAS actuators wherein each SCAS actuator comprises a piston arranged for linear motion within a hydraulic chamber in response to a flow of hydraulic fluid metered by a valve. The piston comprises a flexible rod or quill for providing a linear output along the first axis, the flexible rod or quill being mounted internally within an annular portion of the piston so that a space is defined around the flexible rod or quill. The flexible rod or quill is capable of deforming into the surrounding space in order to accommodate movement of the flexible rod or quill.