Ring Gear Deflection Limiter With Controlled Clearance for Vibration
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Solution Overview
Problem
Gas turbine engines with geared architectures face challenges in maintaining alignment and stability due to loads from the fan section, leading to potential misalignment and vibration issues, which existing technologies do not adequately address.
Innovation Solution
A deflection limiter system is introduced, featuring a ring gear supported by a flexible mechanism that allows controlled radial and circumferential movement, with specific clearances defined by interlocking features between the ring gear and the engine static structure, to maintain alignment and stability of the geared architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the ring gear is rigidly attached to the engine static structure, then alignment stability is improved, but the geared architecture cannot accommodate fan section loads and experiences misalignment
Solution Approach 1:
The deflection limiter transforms the rigid attachment into a dynamic system with controlled movement. The interlocking features allow the ring gear to deflect radially and circumferentially within specific clearance limits (radial: 0.005-0.080 inches, circumferential: 0.005-0.250 inches), enabling the structure to adapt to operational loads while maintaining alignment stability.
2Adaptability or versatility
If the ring gear is allowed to move freely, then accommodation of fan section loads is improved, but misalignment and vibration increase
Solution Approach 1:
The deflection limiter controls the movement parameters of the ring gear by defining specific clearance ranges. Radial clearance is limited to 0.005-0.080 inches and circumferential clearance to 0.005-0.250 inches, allowing controlled adaptation to loads while preventing excessive movement that would generate harmful vibrations and misalignment.
3Device complexity
If traditional rigid supports are used, then structural simplicity is maintained, but misalignment issues occur under operational loads
Solution Approach 1:
The deflection limiter is implemented through segmented interlocking features between the ring gear and engine static structure. These features create discrete radial and circumferential clearances, dividing the movement control into manageable dimensions while maintaining overall structural simplicity and avoiding complex mechanical systems.
Data Source
AI summary
A gas turbine engine includes a turbine section that includes a fan drive turbine. A geared architecture includes a sun gear in driving engagement with the fan drive turbine. A plurality of planet gears surrounds the sun gear. A ring gear surrounds the plurality of planet gears. A deflection limiter mechanically attaches the ring gear to an engine static structure. The deflection limiter includes a first support fixed to the ring gear that has a first interlocking feature and a second support fixed to the engine static structure that has a second interlocking feature. The first and second interlocking features define at least one of a radial clearance of between 0.005 inches (0.127 mm) and 0.080 inches (2.032 mm) or a circumferential clearance of between 0.005 inches (0.127 mm) and 0.250 inches (2.032 mm). A fan section includes a plurality of fan blades in driving engagement with the geared architecture through a fan drive shaft.