Generator Sump Cover Assembly for Low-Pressure Oil Recirculation

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Solution Overview

Problem

Aircraft generators face inefficiencies in lubricant recirculation at low pressures, leading to reduced effectiveness of scavenger pumps, which can result in service interruptions and hardware damage when operating above 25,000 feet due to suctioning mostly air instead of oil from the sump basin.

Innovation Solution

A sump cover and sump basin combination with a multi-point mounting configuration and a perimeter flow recess that defines a fluid flow path, allowing effective suctioning of oil even at pressures below 6 psia by creating a path for oil to flow into the sump cover and be recirculated.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional sump cover and sump basin configuration is used, then the generator structure is simple, but the scavenger pump becomes ineffective at low pressures (above 25,000 feet) and suctions mostly air instead of oil

Engineering Contradiction:
Improvescavenger pump effectivenessVSAvoidsump cover mounting configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sump cover is divided into multiple functional segments: a sump cover support extending outwardly from the sump cover shell, a sump cover shell forming a bowl-shaped structure, and a sump cover gasket. This segmentation allows each component to perform its specific function - the support provides structural attachment points, the shell contains the oil, and the gasket ensures sealing - thereby improving scavenger pump effectiveness while maintaining reasonable overall complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a conventional flat or simple curved sump cover design to a three-dimensional bowl-shaped sump cover shell with a support extending outwardly. This dimensional change creates a multi-point mounting configuration that maintains structural integrity and proper oil flow paths at low pressures, preventing the pump from suctioning air instead of oil

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the sump cover uses a multi-point mounting configuration with sump cover support extending past the perimeter edge, then oil suctioning effectiveness is maintained at low pressures, but the manufacturing complexity increases

Engineering Contradiction:
Improveoil recirculation effectivenessVSAvoidsump cover assembly
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sump cover support, sump cover shell, and sump cover gasket are designed as an integrated assembly where the support extends outwardly from the shell and both are secured together with the gasket. This merging of components into a single multi-point mounting configuration ensures proper oil flow paths and sealing while simplifying the manufacturing process by reducing the number of separate assembly steps

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If a simple sump cover design is used, then manufacturing is easier, but the generator cannot operate continuously above 25,000 feet due to hardware damage from inadequate lubrication

Engineering Contradiction:
Improvegenerator continuous operation capabilityVSAvoidsump cover structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The sump cover is designed with pre-configured multi-point mounting features including the outwardly extending support and bowl-shaped shell that establish proper oil flow paths before the generator operates at high altitudes. This preliminary structural configuration ensures that when the generator operates above 25,000 feet, the scavenger pump immediately effectiveness is maintained, preventing hardware damage from inadequate lubrication

Inventive Principle:
Principle #10Preliminary action

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

Ensures continuous operation and prevents hardware damage by effectively capturing and recirculating oil at low pressures, maintaining generator functionality above 25,000 feet by ensuring the scavenge pump suctions oil rather than air.

Implementation Method 1

a sump cover support extending outwardly from the sump cover shell, past a perimeter edge of the sump cover shell, configured to fit through a sump port and against a sump tube of the sump basin, wherein the sump cover support and the first plurality of fastener features define a multi-point mounting configuration between the sump cover and the sump basin

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 2

the perimeter flow recess defining a fluid flow path between the sump cover and the sump basin

Methodology Applied
Scientific EffectFluid Flow:

Implementation Method 3

The drained lubricant suctioned from the sump basin using a scavenger pump and may then be recirculated

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3798424B1Sump cover assembly for generator
Publication Date: 2023.11.29 HAMILTON SUNDSTRAND CORP
  • EP3798424B1 patent drawingFigure 1
  • EP3798424B1 patent drawingFigure 2
  • EP3798424B1 patent drawingFigure 3

AI summary

Disclosed is a sump cover (200) for a sump basin of a generator of an aircraft, the sump cover having: a sump cover shell (210) shaped as an inverted bowl, a front portion of the sump cover shell including a first plurality of fastener features, each configured to fasten to one of a second plurality of fastener features in the sump basin; and a sump cover support (240) extending outwardly from the sump cover shell, past a perimeter edge of the sump cover shell, configured to fit through a sump port and against a sump tube of the sump basin, wherein the sump cover support and the first plurality of fastener features define a multi-point mounting configuration between the sump cover and the sump basin.