Air Turbine Starter Clutch Integration in Accessory Gearbox
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Solution Overview
Problem
Conventional Air Turbine Starter (ATS) systems face limitations due to inadequate lubrication, leading to oil quality and quantity issues, increased maintenance requirements, and reduced operational lifespan, along with high weight, complexity, and part count.
Innovation Solution
The ATS clutch is relocated into the Accessory Gearbox (AGB) where it benefits from a higher quality and quantity of lubricant through an oil recirculation system, and designed as a modular unit for easy replacement, with the ATS output shaft serving as a clutch race to reduce torque transfer and heat exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the ATS uses a self-contained lubrication system with a shaft-driven oil pump, then the system simplicity is improved, but the oil quality deteriorates due to lack of filtering, pressurizing, and cooling
Solution Approach 1:
The patent merges the ATS lubrication system with the engine's main lubrication system by integrating the ATS clutch into the accessory gearbox. This allows the ATS to benefit from the engine's high-capacity oil reservoir, filtering, pressurizing, and cooling systems, thereby improving oil quality without significantly increasing overall system complexity.
Solution Approach 2:
The engine's main lubrication system, originally designed for engine components, is made universal to also serve the ATS clutch. The oil pump, filter, and cooling systems now perform dual functions: lubricating both engine components and the ATS clutch, eliminating the need for a separate lubrication system for the ATS.
2Reliability
If the ATS clutch is integrated into the accessory gearbox, then the lubrication quality is improved, but the device complexity increases
Solution Approach 1:
The ATS clutch is physically integrated into the accessory gearbox housing, merging two previously separate systems. This integration allows the ATS to access the engine's high-quality lubrication system while utilizing existing structural space, thereby improving lubrication quality without proportionally increasing overall complexity.
Solution Approach 2:
The accessory gearbox is transformed into a multi-functional component that simultaneously houses the engine's lubrication system and the ATS clutch mechanism. This universal design allows one structure to serve multiple purposes: gear reduction, clutch operation, and lubrication distribution, thereby managing complexity efficiently.
3Stability of the object's composition
If the ATS output shaft continues to rotate during engine operation, then the mechanical linkage through the AGB is maintained, but heat exposure and wear increase
Solution Approach 1:
The clutch mechanism enables dynamic control of the ATS output shaft rotation. During engine operation, the clutch can disengage to stop the ATS output shaft from rotating, eliminating unnecessary heat exposure and wear. The mechanical linkage stability is maintained through controlled engagement rather than continuous rotation.
Solution Approach 2:
The clutch mechanism extracts the ATS output shaft from the continuous rotation imposed by the mechanical linkage through the AGB. By allowing selective disengagement, the system removes the harmful continuous rotation while preserving the necessary mechanical connection when needed.
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 enhances the ATS system's maintenance efficiency, extends its service life, reduces weight and complexity, and allows for in-line repair by providing a high-quality lubrication system and modular design.
Implementation Method 1
the ATS clutch module benefits from a higher quality and quantity of lubricant through an oil recirculation system
Implementation Method 2
a shaft-driven oil pump, which draws oil from a sump and injects the oil directly into the clutch or onto a nearby rotating body such that oil is thrown into the clutch via centrifugal forces during ATS operation
Implementation Method 3
After flowing through the clutch, the oil returns to the sump by gravity flow to form a relatively simple, self-contained lubrication system
Data Source
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AI summary
Gas turbine engines (10) including integrated ATS systems. In one embodiment, a gas turbine engine includes an accessory gearbox (AGB (14)) and an integrated ATS system. The AGB includes a gearbox gear train (30) within a gearbox housing (28). The integrated ATS system is removably installed on the AGB and includes an ATS (20) having an air turbine (56) and an output shaft (34) coupled thereto. An ATS clutch module (24) is coupled to the ATS output shaft. An ATS clutch module is further received within the gearbox housing and mechanically couples the ATS output shaft to the gearbox gear train when the integrated ATS system is installed on the AGB.