Turbine Gearbox Assembly with Inline Gears for Torque Transmission

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Solution Overview

Problem

Current gas turbine engine gearbox configurations face inefficiencies in transmitting torque between spools and accessories, often requiring complex reduction transmissions to accommodate different rotational velocities, which can complicate the design and operation.

Innovation Solution

A gearbox assembly with intermeshed first and second gears arranged in distinct planes, along with bevel torque transmission devices, allows independent rotation of spools and efficient torque transmission without the need for additional reduction transmissions, enabling operation at different speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex reduction transmissions are used to accommodate different rotational velocities, then torque transmission between spools and accessories is achieved, but device complexity increases

Engineering Contradiction:
Improvetorque transmission capabilityVSAvoidgearbox design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a third dimension by stacking gear sets in vertical layers within the gearbox housing. Multiple gear sets are arranged at different heights (z-axis) rather than spreading them horizontally, allowing compact torque transmission paths and eliminating the need for complex reduction transmissions while maintaining reliability

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

Solution Approach 2:

The patent nests multiple gear sets within each other in a compact arrangement. First, second, and third gear sets are positioned in overlapping spatial relationships, with gears from different sets intermeshing or operating in close proximity, thereby reducing overall gearbox complexity while achieving reliable torque transmission

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If multiple spools rotate at different velocities, then operational flexibility is improved, but torque transmission efficiency deteriorates

Engineering Contradiction:
Improveoperational flexibilityVSAvoidtorque transmission efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent segments the torque transmission system into multiple independent gear sets (first, second, and third gear sets), each capable of handling different velocity ratios. This segmentation allows each gear set to be optimized for specific speed differences, maintaining torque transmission efficiency while supporting multiple spools rotating at different velocities

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces intermediate gears as mediators between spools rotating at different velocities. These intermediate gear elements facilitate smooth torque transfer across velocity differences by providing staged reduction or multiplication, thereby maintaining efficiency while enabling operational flexibility

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enables efficient torque transmission between spools and accessories at varying rotational velocities, simplifying the gearbox design and enhancing operational efficiency by eliminating the need for complex reduction transmissions.

Implementation Method 1

The gearbox includes a plurality of intermeshed first gears and a plurality of intermeshed second gears

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP3388651B1Turbine engine gearbox assembly with sets of inline gears
Publication Date: 2020.05.27 RTX CORP
  • EP3388651B1 patent drawingFigure 1
  • EP3388651B1 patent drawingFigure 2
  • EP3388651B1 patent drawingFigure 3

AI summary

An assembly is provided for a gas turbine engine with an axial centerline. This assembly includes a gearbox (16), a first torque transmission apparatus (18) and a second torque transmission apparatus (20). The gearbox (16) includes a plurality of first gears (36) and a plurality of second gears (38). The first gears (36) are meshed together and respectively rotatable about parallel first gear axes. The second gears (38) are meshed together and respectively rotatable about parallel second gear axes. Each of the first gear axes and each of the second gear axes is non-parallel with the axial centerline. The first torque transmission apparatus (18) is configured to drive the first gears (36). The second torque transmission apparatus (20) is configured to drive the second gears (38).