Dielectric Compliant Joint for Torque Transfer and Shaft Isolation

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Solution Overview

Problem

In actuated ball valve systems, particularly in aircraft water supply systems, there is a need for a dielectric barrier to prevent electrical faults from the motor end from being transmitted to the metal ball shaft, while maintaining torque transmission, especially when the ball shaft becomes jammed or frozen, and to avoid damage from water ingress.

Innovation Solution

A dielectric insulator insert is placed between the ball shaft and the electric motor, shaped to define alternating flanges and recesses that engage with corresponding features on the shafts, providing a torque transfer mechanism that can withstand short torque peaks and maintain dielectric isolation, using materials like PEEK or rubber for superior compression strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dielectric barrier is provided between the ball shaft and electric motor, then electrical insulation is improved, but torque transmission capability deteriorates

Engineering Contradiction:
Improveelectrical insulationVSAvoidtorque transmission
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

A dielectric insert is introduced as an intermediary component between the ball shaft and electric motor. This insert acts as a mediator that simultaneously provides electrical insulation (improving reliability) and transmits torque (maintaining force transmission). The insert's dual functionality resolves the contradiction by being a material that is both electrically insulating and mechanically strong enough to transmit torque through compression.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the ball shaft is made of metal, then durability is improved, but electrical conductivity increases causing potential faults

Engineering Contradiction:
ImprovedurabilityVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The harmful electrical conductivity property is extracted from the ball shaft system by introducing a dielectric insert that blocks electrical pathways. The metal ball shaft retains its durability benefits while the harmful electrical conductivity is removed or isolated by the dielectric barrier, preventing fault transmission between metal components.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a dielectric insert is used, then electrical isolation is improved, but device complexity increases

Engineering Contradiction:
Improveelectrical isolationVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The dielectric insert is designed to perform multiple functions simultaneously: it provides electrical insulation, transmits torque through compression, and can accommodate misalignment between shafts. By making the insert multi-functional, the overall device complexity is minimized while achieving reliable electrical isolation and torque transmission in a single integrated component.

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

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

The dielectric insert ensures reliable torque transmission and electrical insulation between the motor and ball shaft, preventing electrical shocks and allowing for manual operation in case of motor failure, while maintaining system durability and safety standards.

Implementation Method 1

A dielectric insulator insert is placed between the ball shaft and the electric motor... ensuring reliable torque transmission and electrical insulation between the motor and ball shaft

Methodology Applied
Scientific EffectDielectric insulation: Dielectric

Implementation Method 2

using materials like PEEK or rubber for superior compression strength... able to withstand short torque peaks

Methodology Applied
Scientific EffectCompression resistance: Compression

Data Source

PatentEP4112979B1Compliant joint drive assembly
Publication Date: 2024.12.25 GOODRICH CORP
  • EP4112979B1 patent drawingFigure 1~2
  • EP4112979B1 patent drawingFigure 3
  • EP4112979B1 patent drawingFigure 4

AI summary

A torque transfer assembly comprising a drive shaft (4) and a driven shaft (10) and a dielectric insert (20) arranged to be positioned between the drive shaft and the driven shaft, the insert assembly comprising a body of dielectric material shaped to form an insulating layer and configured to engage, respectively, with a first shaped engagement feature (15) on the drive shaft and a second shaped engagement feature (16) on the driven shaft, in torque transfer engagement, the insulating layer providing a dielectric barrier between the drive shaft and the driven shaft.