Turbine Blade Locking Piece Thick-Plate Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine-blade retaining structures in steam turbines face issues with deformation and cracking of locking pieces due to axial loads and erosion from steam drain, leading to weakened welded portions.
Innovation Solution
The structure incorporates a thick-plate portion for increased rigidity of locking pieces exposed through insertion windows, with a recessed groove to accommodate the welded portion and positioning the welded area behind the thick-plate portion to mitigate erosion, enhancing the structural integrity and assembly ease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If locking pieces are exposed through insertion window portions and joined by welding, then assembly ease is improved, but the welded portions are subject to erosion from steam drain and deformation under axial loads
Solution Approach 1:
The locking piece is designed with a thick-plate portion at its end that is exposed through the insertion window portion. This local thickening increases the rigidity and erosion resistance of the welded area without affecting the overall assembly process. The thick-plate portion is specifically positioned where welding occurs and where erosion from steam drain would otherwise be most damaging.
Solution Approach 2:
The thick-plate portion acts as a protective cushion before the welding process. By providing this reinforced area in advance at the location where welding will occur, the structure is pre-prepared to resist both the welding thermal effects and subsequent operational erosion and loading, preventing deformation and cracking.
2Reliability
If locking pieces are made with increased rigidity to prevent deformation, then structural integrity is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of making the entire locking piece more complex or thicker, the design applies local quality by adding a thick-plate portion only at the specific end region that requires enhanced rigidity. This localized thickening provides the necessary deformation resistance while keeping the rest of the locking piece structure simple and easy to manufacture.
Data Source
AI summary
A turbine-blade retaining structure in which deformation of end portions of locking pieces exposed through an insertion window portion in the axial direction is prevented, and the occurrence of a crack in a welded portion is prevented. At least one of the end portions of adjacent locking pieces exposed through the insertion window portion is provided with a thick-plate portion that expands in the disc-thickness direction so as to be inside the insertion window portion.