Bearing Compartment Oil Drainback With Windage Blocker Recirculation

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Solution Overview

Problem

Gas turbine engines face performance and operational issues due to oil loss from bearing compartments, which can lead to imbalance and thermal problems when oil weeps through seals and enters sensitive areas.

Innovation Solution

An oil drainback assembly with a shaft, threaded section, oil distribution passage, windage blocker, and directional fitting that captures wept oil and directs it back into the oil-wetted zone, utilizing a gutter section and nut for installation, creating a recirculation zone to enhance drainage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a seal system is used to retain oil in the bearing compartment, then oil retention is improved, but oil can still weep through the seal system and cause harmful effects

Engineering Contradiction:

Improveoil retentionVSAvoidoil weeping

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a gutter section as an intermediary component between the seal system and the bearing compartment. This gutter collects wept oil and directs it back into the bearing compartment through a drain passage, preventing oil from entering the compressor or turbine systems while maintaining the seal system's primary retention function

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of allowing wept oil to be discarded or lost, the patent recovers it by channeling it through the gutter section and drain passage back into the bearing compartment. This recovery mechanism eliminates the harmful effects of oil weeping while maintaining the seal system's retention capability

Inventive Principle:

Principle #34Discarding and recovering

2Loss of substance

If oil is allowed to drain back into the bearing compartment, then oil consumption is reduced, but windage can prevent effective drainage

Engineering Contradiction:

Improveoil consumptionVSAvoidwindage interference

Core Design Contradiction:

Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the windage blocker from the bearing compartment environment by positioning it in the gutter section where it can counteract windage forces without interfering with the rotating components. This allows effective oil drainage while isolating the windage compensation mechanism from the harmful rotational airflow

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The windage blocker is designed with an asymmetric geometry that creates a low-pressure zone on the suction side, exploiting the asymmetric pressure distribution caused by windage forces to enhance oil drainage rather than simply blocking the flow

Inventive Principle:

Principle #4Asymmetry

3Object-generated harmful factors

If a complex oil collection system is implemented, then oil weeping is prevented, but device complexity increases

Engineering Contradiction:

Improveoil weeping preventionVSAvoidsystem complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the oil collection, windage compensation, and drainage functions into a single integrated gutter section assembly. This combines multiple functions that would otherwise require separate components, preventing oil weeping while maintaining relatively simple system architecture

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The gutter section serves multiple functions simultaneously: it collects wept oil, houses the windage blocker, provides structural support, and directs oil flow through the drain passage. This multi-functionality reduces the number of separate components needed while effectively preventing oil weeping

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

Effectively captures and recirculates wept oil, reducing oil consumption and preventing it from entering the compressor system or causing thermal issues, thereby enhancing engine performance and durability.

Implementation Method 1

Methodology Applied

Scientific EffectWindage:

Data Source

PatentUS11719127B2Oil drainback assembly for a bearing compartment of a gas turbine engine

Publication Date: 2023.08.08 RTX CORP

AI summary

A bearing compartment of a gas turbine engine includes a rotationally fixed structure defined about an engine longitudinal axis; a gutter section formed in the front support; an oil drainback assembly mountable to the gutter section to direct oil into a drain passage to communicate oil from the gutter.