Zero-Moment Fitting Spherical Bearing Rotation

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Solution Overview

Problem

Conventional fittings used to secure fluid conduits to structures, such as bulkheads, experience premature fatigue or failure due to moments created by the geometry and pressurized fluids within the conduits, leading to undesirable loads and potential failure.

Innovation Solution

A zero-moment fitting that incorporates a spherical bearing allowing rotational movement of the fluid conduit without imposing loads on the fitting, using a housing with a spherical bearing that rotates freely within it, eliminating moments on the fitting and structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fittings are used to secure fluid conduits to structures, then the conduits are firmly attached and secured, but moments created by pressurized fluids and conduit geometry cause fatigue and premature failure of the fittings

Engineering Contradiction:
Improvefitting durabilityVSAvoidfitting load capacity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A spherical bearing is introduced as an intermediary element between the fluid conduit and the fitting structure. This bearing allows rotational movement and angular adjustment while supporting the conduit weight, thereby eliminating moment loads from the fitting attachment points and preventing fatigue failure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fitting system transitions from a rigid, fixed-position attachment to a dynamic system that permits rotational movement and angular adjustment. The spherical bearing enables the conduit to move dynamically in response to pressure changes and thermal expansion without creating damaging moments on the fitting.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the fluid conduit geometry creates moments around the central axis, then the conduit can be routed through structures, but these moments transfer loads to the fittings and bulkheads causing fatigue

Engineering Contradiction:
Improveconduit routing flexibilityVSAvoidmoment load on fitting
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The spherical bearing acts as a mediator that absorbs and accommodates the moment loads generated by conduit geometry. It allows the conduit to maintain its routed position while preventing these moments from being transferred to the fitting and bulkhead structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful moment loads are extracted from the fitting system by introducing the spherical bearing, which independently handles these loads through its rotational capability, leaving the fitting to only support axial and radial forces.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the fitting allows rotational movement to prevent moment loads, then fatigue is reduced, but the fitting must accommodate angular rotation without compromising secure attachment

Engineering Contradiction:
Improvefitting fatigue resistanceVSAvoidrotational movement capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The spherical bearing provides a controlled rotational interface that enables angular movement while maintaining secure attachment. It mediates between the need for rotational freedom and the requirement for firm attachment, allowing movement only in directions that prevent moment load generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fitting system incorporates dynamic rotational capability through the spherical bearing, which allows controlled angular adjustment while maintaining secure attachment. This dynamic feature enables the system to adapt to operational requirements without compromising attachment integrity.

Inventive Principle:
Principle #15Dynamics

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 zero-moment fitting enables rotational movement of fluid conduits without transferring loads to the fitting, thereby preventing fatigue and failure, ensuring secure and durable attachment while allowing for angular rotation.

Implementation Method 1

A zero-moment fitting that incorporates a spherical bearing allowing rotational movement of the fluid conduit without imposing loads on the fitting

Methodology Applied
Scientific EffectSpherical bearing rotation: Ball Bearing

Data Source

PatentEP2738434B1Zero-moment fitting
Publication Date: 2019.08.14 THE BOEING CO
  • EP2738434B1 patent drawingFigure 1~2
  • EP2738434B1 patent drawingFigure 3
  • EP2738434B1 patent drawingFigure 4

AI summary

Apparatus, systems, and methods provide for a zero-moment fitting, wherein the fitting (100) comprises: a spherical bearing (110) comprising a conduit aperture (112) configured to receive a fluid conduit (102) traversing the spherical bearing (110); and a bearing housing (120) configured to retain the spherical bearing (110) within the bearing housing (120), to allow for rotation of the spherical bearing (110) within the bearing housing (120), and to be fixedly coupled to a structure (140).