Turbine Blade Base Servicing Using Vibratory Axial-Circumferential Force
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Solution Overview
Problem
The complex geometry of latter stage turbine blades in turbomachines, featuring interlocking shrouds and tied-in edges, complicates their assembly and disassembly due to the interlocking profiles that inhibit direct axial sliding, making conventional mechanical force-based installation and removal impractical.
Innovation Solution
An apparatus and method utilizing an operative head that imparts axial and circumferential forces, combined with mechanical vibrations, to engage and transfer turbine blades relative to the rotor wheel, allowing for installation or removal without disassembling major turbomachine components, using a mount coupled to the turbomachine assembly and an actuator to align and move the operative head along an axial guide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional mechanical force-based installation and removal methods are used, then simple turbine blade geometries can be assembled, but complex geometries with interlocking shrouds and tied-in edges cannot be installed or removed
Solution Approach 1:
The patent applies mechanical vibrations through a vibratory mechanism that generates oscillatory motion in the operative head. This vibration creates dynamic forces that temporarily overcome the static friction and mechanical interlocking between adjacent blades, enabling the operative head to slide blades axially onto or off the rotor wheel despite the complex interlocking shroud geometries.
Solution Approach 2:
The vibratory mechanism produces periodic oscillations at specific frequencies that cyclically vary the contact forces between blades. This periodic action creates moments during each cycle when the interlocking forces are minimized, allowing continuous axial movement of blades during installation or removal operations.
2Strength
If interlocking shrouds are used to increase blade rigidity and confine working fluid, then turbine performance improves, but direct assembly and disassembly of blades is impeded
Solution Approach 1:
The vibratory mechanism generates mechanical oscillations that temporarily reduce the effective engagement force between interlocking shrouds of adjacent blades. This allows the operative head to move blades axially during assembly or disassembly while maintaining the full interlocking shroud configuration that provides structural rigidity and fluid confinement during turbine operation.
Solution Approach 2:
The system changes the dynamic parameters of the blade assembly process by introducing vibratory motion, which alters the friction and contact force characteristics between interlocking shrouds. This enables blade movement during installation/removal without modifying the shroud geometry or reducing blade rigidity in the assembled state.
3Productivity
If complex blade geometries are applied to improve aerodynamic performance, then turbine efficiency increases, but assembly challenges increase
Solution Approach 1:
The vibratory mechanism provides a universal solution for handling complex blade geometries by creating dynamic conditions that reduce inter-blade friction and mechanical interference. This allows highly articulated blades with complex airfoil profiles, variable pitch angles, and sophisticated shroud configurations to be installed or removed without simplifying their geometry or compromising their aerodynamic performance.
Solution Approach 2:
The operative head with vibratory mechanism serves as an intermediary tool that mediates between the complex blade geometries and the assembly process. It transfers controlled forces to individual blades while the vibration component overcomes the complexity-induced friction and interference, enabling assembly without modifying blade design.
4Ease of operation
If major turbomachine components are not disassembled for blade servicing, then accessibility to blades is improved, but applying force to blades becomes more difficult
Solution Approach 1:
The vibratory mechanism mounted on the operative head generates localized oscillatory forces directly at the blade contact point. This concentrated vibratory energy overcomes the mechanical resistance of interlocking shrouds and enables effective force application to individual blades even when the turbine assembly remains substantially intact and accessible only from limited service positions.
Solution Approach 2:
The operative head acts as an intermediary device that bridges the gap between limited external accessibility and the need to apply substantial forces to blades. It transmits and concentrates forces from the actuator and vibratory mechanism directly to the target blade, enabling effective servicing without disassembling major components like the diffusor barrel.
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
Enables efficient installation and removal of turbine blades with complex geometries, overcoming mechanical resistance from interlocking profiles and allowing for servicing without disassembling the diffusor barrel or other components, thus improving accessibility and reducing assembly challenges.
Implementation Method 1
the operative head is shaped to impart an axial and a circumferential force against the turbine blade base
Implementation Method 2
the operative head is slidably coupled to the mount such that the operative selectively engages the axial sidewall of the turbine blade base
Data Source
AI summary
Embodiments of the present disclosure relate to the installation or removal of turbine blades at a turbine blade base thereof. An apparatus according to the present disclosure can include: an operative head configured to engage an axial sidewall of a turbine blade base; and a mount removably coupled to a portion of a turbomachine assembly by a coupler, wherein the operative head is slidably coupled to the mount such that the operative selectively engages the axial sidewall of the turbine blade base, and wherein the operative head is shaped to impart an axial and a circumferential force against the turbine blade base.