Gas Turbine Thrust Bearing Load Control via Fan Nozzle Adjustment

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Solution Overview

Problem

Geared turbofan engines experience high bearing thrust loads due to the gear train arrangement, which are not actively managed, leading to potential wear and maintenance challenges.

Innovation Solution

A flow control device is used to adjust the fan nozzle exit area in response to measured thrust bearing loads, actively managing the axial load on the thrust bearing by manipulating the bypass flow, thereby regulating the bearing load to desired levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a gear train is arranged between the low pressure turbine and the fan, then the engine achieves geared turbofan configuration, but the bearing thrust loads become substantially higher

Engineering Contradiction:

Improvegeared turbofan configurationVSAvoidbearing thrust load

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

A sensor monitors the actual thrust bearing load and provides feedback to a controller, which then commands the flow control device to adjust the bypass flow and actively manage the bearing load to desired levels

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The flow control device changes the physical parameters of the bypass flow (flow rate, pressure, or direction) to dynamically adjust the axial load on the thrust bearing, reducing it from undesired high levels to desired levels

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If bearing load is not actively managed, then the system structure remains simple, but bearing wear increases and maintenance challenges arise

Engineering Contradiction:

Improvesystem structureVSAvoidbearing lifespan

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system uses automated sensing and control to self-regulate bearing load without requiring manual intervention, with the controller automatically adjusting flow control based on sensor feedback to protect the bearing

Inventive Principle:

Principle #25Self-service

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 approach effectively reduces the axial load on the thrust bearing, minimizing wear and extending its lifespan by dynamically adjusting the fan nozzle exit area based on real-time load monitoring.

Implementation Method 1

A flow control device is adapted to effectively change the fan nozzle exit area

Methodology Applied

Scientific EffectBypass flow:

Data Source

PatentEP2009249B1Control system of the axial bearing load of a gas turbine engine and corresponding method of regulating this load

Publication Date: 2013.10.23 UNITED TECH CORP

Figure 1~2

AI summary

A turbine engine (10) provides a spool (14) supporting a turbine (18). The spool (14) is arranged in a core nacelle (12) and includes a thrust bearing (49). A fan (20) is arranged upstream from the core nacelle (12) and is coupled to the spool (14). A fan nacelle (34) surrounds the fan (20) and core nacelle (12) and provides a bypass flow path (39) that includes a fan nozzle exit area (40). A flow control device is adapted to effectively change the fan nozzle exit area (40). A controller (50) is programmed to monitor the thrust bearing (49) and command the flow control device in response to an undesired load on the thrust bearing (49). Effectively changing the fan nozzle exit area (40) with the flow control device actively manages the bearing thrust load to desired levels.