Turbomachine Rotor Movable Ring Wear Mitigation
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Solution Overview
Problem
The existing turbomachine rotor designs suffer from premature wear of the movable ring due to repeated contacts with the axial retaining hooks, leading to deterioration by contact wear and fretting.
Innovation Solution
A movable ring assembly with outer peripheral toothing, where each tooth has a protective element such as a nickel-chromium coating or a protective part, is introduced to reduce contact with the axial retaining hooks and mitigate wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the movable ring is made with outer peripheral toothing to retain blades, then blade retention is achieved, but contact wear and fretting occur due to repeated contacts with axial retaining hooks
Solution Approach 1:
A protective coating layer (such as nickel-chromium or ceramic coating) is applied to the outer face of the teeth of the movable ring. This coating acts as an intermediary between the movable ring teeth and the axial retaining hooks, preventing direct metal-to-metal contact and thereby eliminating contact wear and fretting while maintaining the blade retention function.
2Adaptability or versatility
If the ring arm is made with permissive bending shape to allow movement when hot, then thermal expansion accommodation is achieved, but repeated contacts with axial retaining hooks cause deterioration
Solution Approach 1:
The protective coating on the outer face of the teeth serves as a sacrificial intermediary layer that allows the ring arm to move thermally while preventing direct contact wear between the movable ring and axial retaining hooks, thus maintaining component durability despite repeated contacts.
Solution Approach 2:
The protective coating is applied beforehand to the teeth surfaces that will undergo repeated contact. This pre-applied protective layer cushions against the inevitable repeated contacts that occur during thermal operation, preventing deterioration before it can affect the base material.
3Manufacturing precision
If the movable ring blocks each blade via groove and outer peripheral toothing, then axial retention is achieved, but the groove and toothing suffer from contact wear up to 2mm thickness loss
Solution Approach 1:
A protective coating is applied to the outer face of the teeth that engage with the grooves of the axial retaining hooks. This coating layer prevents direct contact wear between the toothing and groove interfaces, maintaining the precise axial retention positioning while eliminating the 2mm thickness loss that would otherwise occur.
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 implementation of the movable ring assembly significantly reduces or eliminates premature wear of the movable ring by limiting contact with the axial retaining hooks, thereby extending the component's lifespan and maintaining operational efficiency.
Implementation Method 1
the material of said coating may have nickel and chromium
Data Source
AI summary
Movable ring assembly for a turbomachine rotor, the movable ring including an outer peripheral toothing, each tooth of the outer peripheral toothing having an inner face intended to be positioned facing a blade root of the rotor, and an outer face opposite to the inner face and intended to be positioned facing an axial retaining hook arranged on the blade root. Furthermore, the movable ring assembly includes at least one protective element arranged on the outer face of at least one tooth of the outer peripheral toothing.