Dual-Speed Planetary Gearset With Ring Lock for Variable Propulsor Speed
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Solution Overview
Problem
Gas turbine engines with traditional single-speed propulsor systems lack the flexibility to operate efficiently at multiple speeds, which is necessary for optimal performance in various aircraft operations, including vertical takeoff and land (VTOL) applications.
Innovation Solution
A planetary gear drive system that includes a sun gear, planet gears, and ring gears with a ring lock mechanism, allowing for selective engagement of different gear tooth sets to achieve two distinct operating speeds, enabling the propulsor to rotate at different speeds based on the engagement of specific gear tooth sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single-speed propulsor system is used, then the device complexity is reduced, but the adaptability to different operational conditions deteriorates
Solution Approach 1:
The planetary gear system enables dynamic speed adjustment by allowing the propulsor to operate at two distinct speeds (first speed and second speed) through selective engagement of different gear tooth sets on the ring lock, transforming a static single-speed system into a dynamic multi-speed system that adapts to varying operational requirements
Solution Approach 2:
The ring lock with multiple gear tooth sets serves multiple functions: it can engage with different ring gears to provide different speed ratios, and can selectively connect to either the first ring gear or second ring gear, making a single component capable of providing multiple operating modes for the propulsor
2Productivity
If a single-speed propulsor system is used, then the device complexity is reduced, but the propulsion efficiency deteriorates
Solution Approach 1:
The system dynamically adjusts the propulsor speed based on operational conditions, operating at a first speed under certain conditions and a second speed under other conditions, optimizing propulsion efficiency across different flight regimes rather than being constrained to a single fixed speed
Solution Approach 2:
The planetary gear system changes the speed parameter of the propulsor by engaging different gear tooth sets, allowing the propulsor to operate at two distinct speed levels (first speed and second speed) to optimize efficiency for different operational requirements
3Adaptability or versatility
If a dual speed planetary gear system is implemented, then the adaptability to different operational conditions is improved, but the device complexity increases
Solution Approach 1:
The ring lock is segmented into multiple gear tooth sets (first gear tooth set and second gear tooth set), each engaging with different ring gears, allowing the system to provide multiple speed ratios through a single segmented component rather than requiring separate gear mechanisms for each speed
4Productivity
If a dual speed planetary gear system is implemented, then the propulsion efficiency is improved, but the device complexity increases
Solution Approach 1:
The planetary gear system enables dynamic speed adjustment by allowing the propulsor to operate at two distinct speeds (first speed and second speed) through selective engagement of different gear tooth sets on the ring lock, transforming a static single-speed system into a dynamic multi-speed system that optimizes propulsion efficiency across different flight regimes
Solution Approach 2:
The ring lock with multiple gear tooth sets serves multiple functions: it can engage with different ring gears to provide different speed ratios, and can selectively connect to either the first ring gear or second ring gear, making a single component capable of providing multiple operating modes for the propulsor
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 allows the gas turbine engine to operate efficiently at two distinct speeds, improving propulsion efficiency and enabling the engine to adapt to different operational conditions, such as idle conditions, by selectively engaging different gear tooth sets within the planetary gear system.
Implementation Method 1
The turbine shaft drives the propulsor input shaft through a gear reduction. The gear reduction is a planetary gear system having a sun gear rotating with the turbine shaft and engaging and driving a plurality of planet gears.
Implementation Method 2
The ring lock is constrained against rotation, such that when the first gear tooth set on the ring lock engages the first ring gear tooth set, rotation of the first ring gear is stopped
Data Source
AI summary
A gear carrier drives a propulsor. Two ring gears engage with respective tooth locations on planet gears. A first gear tooth set on a ring lock selectively engage with a first ring gear and a second gear tooth set on a ring lock selectively engage with a second ring gear. When the first gear tooth set on the ring lock engages the first ring gear, rotation of the first ring gear stops, and the planet gears drive the carrier at a first speed. When the second ring lock gear tooth set engages the second ring gear, rotation of the second ring gear stops and the planet gear drives the carrier at a second speed which is different than the first speed. An aircraft and a method are also disclosed.