Replaceable Wear Strip for Turbine Inter Stage Seal Housing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The downstream contact sealing surface of inter stage seal housings in turbine engines wears over time, leading to leaks and reduced efficiency, requiring time-consuming and distorting weld repairs during maintenance.

Innovation Solution

A seal assembly with replaceable wear strips is introduced, featuring a circumferential groove with through holes and fasteners that secure segment strips, allowing for easy replacement and alignment, preventing leakage and accommodating thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If weld building repair is used to restore the downstream contact sealing surface, then the sealing surface is restored to its original shape, but the repair process is very time consuming and causes distortion of the sealing surface

Engineering Contradiction:
Improvesealing surface shapeVSAvoidmaintenance time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The sealing surface is segmented into a replaceable wear strip that can be independently replaced. The wear strip is divided into multiple segments that can be individually installed and removed, allowing rapid replacement without affecting the entire seal housing structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wear strip is extracted as a separate replaceable component from the seal housing. This allows the wear strip to be removed and replaced independently when worn, eliminating the need for time-consuming weld repairs on the main housing structure.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If weld building repair is used to restore the downstream contact sealing surface, then the sealing surface is restored, but the sealing surface becomes distorted which impairs turbine engine performance

Engineering Contradiction:
Improvesealing functionVSAvoidsealing surface flatness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The wear strip is designed as a disposable or replaceable component with a limited service life. When worn, it is replaced with a new strip rather than repaired, ensuring the sealing surface always has the original precise geometry without distortion from welding operations.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Productivity

If a replaceable wear strip is used instead of weld repair, then maintenance time is reduced and distortion is avoided, but the device complexity increases due to additional components

Engineering Contradiction:
Improvemaintenance efficiencyVSAvoidseal assembly structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The seal assembly transitions from a static welded structure to a dynamic system with replaceable components. The wear strip can be dynamically removed and replaced based on wear conditions, enabling rapid maintenance without complex repair procedures.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2606204B1Inter stage seal housing having a replaceable wear strip
Publication Date: 2020.10.07 MITSUBISHI HITACHI POWER SYST AMERICAS
  • EP2606204B1 patent drawingFigure 1
  • EP2606204B1 patent drawingFigure 2
  • EP2606204B1 patent drawingFigure 3

AI summary

An inter stage seal housing for a turbine engine having upper and lower half inter stage seal housings in which a contact sealing surface of the seal housing is restored after an interval of engine operation. The contact sealing surface is restored by fitting a replaceable wear strip on the downstream sealing surface of the seal housing. In order to fit the replaceable wear strip, a circumferential groove is machined along an outer peripheral edge of the seal housing. The groove is machined to include axial location and radial retention such that the wear strips can be slid into the upper half and lower half inter stage seal housing circumferentially from the horizontal joint. The groove includes through holes and the wear strips include corresponding threaded holes such that the wear strips can be fastened in the groove by fasteners and fastener retention hardware.