Hydrodynamic Oil Collector Inlets for Aircraft Reducer Satellites

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Solution Overview

Problem

In mechanical reduction gears of turbomachines, particularly in aircraft, the recirculation of hot lubricating oil due to centrifugation leads to increased losses, temperature rise, reduced oil levels, and inefficient oil recycling, causing ventilation losses and increased oil consumption.

Innovation Solution

An oil collector with hydrodynamic profiled inlets on its side faces, arranged in a matrix configuration, effectively captures and directs hot oil projected by satellites, minimizing pressure drops and flow disturbances, and efficiently routes it to recycling outlets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If deflectors or oil collectors are installed between satellites to divert oil spray, then oil recirculation is reduced and ventilation losses decrease, but the space between satellites and collector becomes saturated with oil leading to satellite bubbling and reduced lubrication efficiency

Engineering Contradiction:
Improveventilation lossesVSAvoidlubrication efficiency
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The collector body is designed with multiple oil inlets distributed across its lateral faces, creating localized oil collection zones. Each inlet area is optimized to capture oil from specific satellite regions, ensuring uniform oil distribution and preventing localized saturation that would cause bubbling while maintaining effective oil diversion to reduce ventilation losses

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The oil inlets are arranged in a matrix pattern across the lateral faces of the collector, transitioning from a single-point collection to a distributed two-dimensional array. This dimensional expansion increases the total oil capture surface area, allowing the collector to handle larger oil quantities efficiently without creating saturation zones, thus resolving the contradiction between oil diversion effectiveness and lubrication efficiency

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

2Device complexity

If a conventional oil collector with simple inlets is used, then the device complexity is low, but pressure losses and flow disturbances in oil flow toward the collector cavity increase

Engineering Contradiction:
Improvecollector structureVSAvoidpressure losses
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The oil inlets are designed with curved, hydrodynamic profiles rather than sharp edges or straight channels. These curved surfaces guide oil flow smoothly into the collector cavity, reducing flow separation and turbulence. The hydrodynamic shaping minimizes pressure losses and flow disturbances while maintaining a relatively simple overall collector structure

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The inlet geometry parameters are optimized to achieve favorable flow characteristics. The inlet cross-sectional area and shape are specifically designed to match the expected oil flow patterns from satellites, creating smooth transitions that reduce flow resistance and pressure drops without requiring complex additional components

Inventive Principle:
Principle #35Parameter changes

3Temperature

If the number of oil inlets is increased to capture more oil, then oil recirculation is better controlled and satellite temperature decreases, but the device complexity increases

Engineering Contradiction:
Improvesatellite temperatureVSAvoidinlet configuration
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The oil collection system is segmented into multiple distributed inlets across the collector's lateral faces rather than using a single large inlet or complex multi-stage system. Each inlet is a simple structural feature that collectively provides effective oil capture, reducing satellite temperature through improved oil circulation while maintaining low device complexity through the simplicity of individual inlet elements

Inventive Principle:
Principle #1Segmentation

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 solution reduces ventilation losses, satellite temperature, and oil consumption, enhancing the efficiency of oil recycling and maintaining optimal oil levels within the system.

Implementation Method 1

The lubricating oil from the satellites is projected by centrifugal force onto the lateral faces of the collector

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

said inlets (30) have a hydrodynamic profile; a wall with a hydrodynamic profile is a wall that is designed to minimize disturbances in the flow of a fluid over that wall

Methodology Applied
Scientific EffectHydrodynamic profile:

Data Source

PatentEP3767134B1Oil collector for a mechanical gear of an aircraft turbine engine
Publication Date: 2022.12.14 SAFRAN TRANSMISSION SYST
  • EP3767134B1 patent drawingFigure 1
  • EP3767134B1 patent drawingFigure 2
  • EP3767134B1 patent drawingFigure 3~4

AI summary

Oil collector (20) for a mechanical reducer (6) of a turbomachine (1), in particular of an aircraft, this reducer comprising a body having two opposing lateral faces (20a) configured to extend partly around satellites (8) of said reducer, the collector further comprising an internal cavity (28) for oil circulation connected on the one hand to oil inlets (30) located on said faces, and on the other hand to at least one oil outlet (26), characterized in that at least one of said faces comprises columns and rows of several inlets (30) each having a recess (32) having a progressively increasing cross-section, each recess (32) being delimited by walls (32a, 32b, 32c, 32d), at least some of said walls (32a, 32b) having a hydrodynamic profile.