Composite Actuator Piston Rod with Embedded Bolt

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional metallic actuators in aircraft systems are heavy due to their complex geometries and high strength requirements, making them unsuitable for weight-sensitive applications, and existing methods to attach composite materials to metal components compromise the structural integrity of the composite actuator rod tubes.

Innovation Solution

A composite actuator rod tube made of lightweight polymer matrix composite materials, such as carbon fiber, with a tapered end that engages with metal components without threading or drilling, and an embedded conical bolt for secure attachment, ensuring structural integrity and reduced weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metallic materials are used for actuator components to achieve high strength and complex geometries, then strength and structural integrity are improved, but weight increases significantly

Engineering Contradiction:
Improvestructural integrityVSAvoidactuator weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The piston rod is constructed as a composite structure with a metallic core providing strength and structural integrity, and a polymer matrix composite outer layer providing lightweight properties and fatigue resistance. This composite construction allows the actuator to maintain high strength while significantly reducing weight compared to conventional all-metallic designs.

Inventive Principle:
Principle #40Composite materials

2Force

If threading or drilling is used to attach composite materials to metal components, then secure attachment is achieved, but structural integrity of composite materials is compromised

Engineering Contradiction:
Improveattachment securityVSAvoidcomposite material integrity
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

A tapered metal insert acts as an intermediary component between the composite piston rod and the metallic piston. The insert is embedded within the composite material during manufacturing, providing a secure mechanical interface for the piston while avoiding the need to thread or drill the composite material itself, thus preserving its structural integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The metal insert is pre-positioned and embedded within the composite piston rod during the manufacturing process, before final assembly. This preliminary action ensures proper alignment and secure attachment without requiring subsequent drilling or threading operations that would compromise the composite material.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3051148B1Actuator with a composite piston rod and a metallic piston
Publication Date: 2019.11.06 GOODRICH CORP
  • EP3051148B1 patent drawingFigure 1A~1B
  • EP3051148B1 patent drawingFigure 2~3A
  • EP3051148B1 patent drawingFigure 3B~3C

AI summary

The present disclosure describes composite actuator piston rods and methods for making such rods. Composite actuator piston rods of the present disclosure may include a tapered end 36 and an embedded bolt 38 positioned within the tapered end. A piston head 44 may be secured to the embedded bolt by a nut 58. Further, a keyed locking cup washer 62 and jam nut 50 may further secure the piston head to the embedded bolt.