Gearbox Mounting Assembly for Dynamic Misalignment Control
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Solution Overview
Problem
The dynamic loading of gas turbine engines induces relative movements among gearbox components, leading to misalignments and increased stress, which can result in premature failure and wear of parts like bearings and seals, particularly in power gearboxes used to transfer torque from a turbine shaft to a fan shaft.
Innovation Solution
A mounting assembly for the gearbox assembly, comprising flex couplings, flex mounts, and fan frames, designed to manage lateral, bending, and torsional stiffness and damping to accommodate the dynamic loading, ensuring proper alignment and reducing stress on gearbox components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the gearbox assembly is rigidly mounted to the engine structure, then structural stability is improved, but misalignment and stress under dynamic loading increase
Solution Approach 1:
The patent employs flexible mounting members including flex mounts and flex couplings that utilize elastomeric materials to provide flexible connections between the gearbox assembly and engine structure. These flexible elements accommodate dynamic loading and relative movements while maintaining structural stability, preventing misalignment and reducing stress on components like bearings and seals.
Solution Approach 2:
The patent specifies impedance parameter ratios for the mounting members, where the lateral and bending impedance parameters are designed to be less than or equal to 0.5 times the fan frame impedance, while torsional impedance is greater than or equal to 0.01 times the fan frame impedance. These parameter optimizations allow the mounting assembly to manage dynamic loading effectively, balancing structural stability with misalignment prevention.
2Reliability
If the mounting assembly uses flexible elements to reduce misalignment, then component durability is improved, but structural stiffness decreases
Solution Approach 1:
The flexible mounting members use elastomeric materials that provide flexibility to accommodate dynamic loading and relative movements, thereby improving component durability by reducing misalignment and stress. The flex mounts and flex couplings maintain sufficient structural stiffness through their elastomeric construction while allowing necessary movement.
Solution Approach 2:
By optimizing the impedance parameters of the mounting members, the patent achieves a balance between flexibility and stiffness. The specific impedance ratio constraints ensure that the mounting assembly has enough flexibility to prevent misalignment under dynamic loading while maintaining sufficient structural stiffness to support the gearbox assembly.
3Reliability
If the mounting assembly allows relative movement to accommodate dynamic loading, then misalignment is reduced, but structural stability decreases
Solution Approach 1:
The flexible mounting members with elastomeric materials allow controlled relative movement between the gearbox assembly and engine structure, accommodating dynamic loading conditions. This flexibility prevents misalignment while maintaining structural stability through the inherent properties of the elastomeric materials and the designed impedance parameters.
Solution Approach 2:
The patent optimizes the impedance parameters of the mounting members to achieve the right balance between allowing relative movement and maintaining structural stability. The specific constraints on lateral, bending, and torsional impedance ratios ensure that the mounting assembly prevents misalignment under dynamic loading while preserving necessary structural stability.
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
The mounting assembly extends the life of gearbox components by minimizing misalignments and eccentric loading, thereby enhancing durability and reducing the risk of premature failure.
Implementation Method 1
flex coupling configured to mount a first gear of the gearbox assembly to a rotating shaft of the gas turbine engine, a flex mount configured to mount a second gear of the gearbox assembly to an engine static structure
Implementation Method 2
designed to manage lateral, bending, and torsional stiffness and damping to accommodate the dynamic loading, ensuring proper alignment and reducing stress on gearbox components
Data Source
AI summary
A mounting assembly for a gearbox assembly of a gas turbine engine includes at least one mounting member configured to mount a gear of the gearbox assembly to a component of the gas turbine engine, the at least one mounting member characterized by a lateral impedance parameter, a bending impedance parameter, and a torsional impedance parameter. A gas turbine engine includes the mounting assembly. The at least one mounting member may be a flex mount, a fan frame, or a flex coupling. The gas turbine engine also includes a heat exchanger including an inner peripheral wall and an outer peripheral wall extending between an inlet and an outlet. The inner peripheral wall and the outer peripheral wall define a flow channel therebetween. The heat exchanger includes a plurality of fins disposed in the flow channel and dividing the flow channel into a plurality of flow passages.