Torque Connector Scuppers for Centrifugal Interface Lubrication
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Solution Overview
Problem
The existing fan drive gear systems in gas turbine engines face challenges with lubricant distribution, as pressurized lubricant passages through pins can complicate assembly and increase costs, and there is a need for alternative lubricant arrangements that maintain efficiency while reducing complexity and cost.
Innovation Solution
The fan drive gear system incorporates a scupper that directs lubricant into the space between the torque frame and carrier, utilizing centrifugal forces generated by rotation to drive lubricant through these interfaces, eliminating the need for pressurized lubricant passages and simplifying the assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressurized lubricant passages are provided through each pin to lubricate the sliding interface, then lubrication reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts the lubricant delivery function from the pins themselves and relocates it to the carrier structure. The carrier now contains lubricant passages that deliver lubricant to the sliding interface, while the pins serve only as structural connectors. This separation of functions simplifies pin manufacturing and assembly while maintaining reliable lubrication.
Solution Approach 2:
The carrier is designed to serve multiple functions: it supports the gears, provides structural integrity to the gear assembly, and delivers lubricant to the sliding interface through integrated passages. This multi-functionality eliminates the need for separate lubricant delivery mechanisms through each pin.
2Reliability
If pressurized lubricant passages are provided through each pin, then lubrication efficiency is improved, but manufacturing cost increases
Solution Approach 1:
The lubricant delivery function is extracted from the pins and consolidated into the carrier structure. This allows for centralized manufacturing of lubricant passages in the carrier rather than requiring complex internal passages in each individual pin, significantly reducing manufacturing cost while maintaining lubrication efficiency.
Solution Approach 2:
The lubricant delivery system is merged with the carrier structure, combining what were previously separate functions (carrier support and lubricant delivery) into a single integrated component. This consolidation reduces the total number of parts and simplifies manufacturing processes.
3Reliability
If pins are designed with internal lubricant passages, then lubrication is maintained, but assembly difficulty increases
Solution Approach 1:
The lubricant passages are extracted from the pins and relocated to the carrier. This allows pins to be simple solid connectors that can be easily assembled by pressing them into the carrier, eliminating the need for complex alignment and insertion of pins with internal passages.
Solution Approach 2:
Instead of delivering lubricant through the pins from the gear mesh side, the system inverts the approach by delivering lubricant through the carrier to the sliding interface. This reversal simplifies the pin design and assembly process while achieving the same lubrication objective.
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 solution ensures continuous lubrication of the interfaces between the torque frame and carrier without complex machining, reducing wear and maintaining lubricant efficiency while simplifying the assembly and reducing costs by eliminating the need for pressurized lubricant flow.
Implementation Method 1
the carrier and torque frame are configured to rotate about an axis of rotation and generate centrifugal forces for driving exhaust lubricant through the space between each of the plurality of connectors and one of the carrier and torque frame
Data Source
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AI summary
A turbofan engine includes a fan rotatable about an axis, a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a fan drive gear system including a carrier for supporting a plurality of gears. A torque frame is attached to the carrier. A plurality of connectors extends between the carrier and torque frame for securing the torque frame to the carrier. A scupper captures lubricant during gear operation and directing lubricant into a space between at least one of the plurality of connectors and at least one of the torque frame and the carrier.