Guided Non-Contact Seal Assembly for Rotor Clearance Stability
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Solution Overview
Problem
Rotational equipment seal assemblies face leakage due to asymmetric deflection and clearance variations, and are vulnerable to buckling from circumferential loads, limiting the effectiveness of non-contact seals.
Innovation Solution
A non-contact seal assembly for rotational equipment featuring a stator structure with seal shoes, a seal base, spring elements, and a shoe support plate, where the seal shoes are arranged in an annular array, supported by spring elements and shoe support tabs, and optionally with shoe support slots and recesses, to provide radial and circumferential support, reducing the likelihood of buckling and improving sealing efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-contact seals are used to accommodate asymmetric deflection, then sealing effectiveness is improved, but clearance variations between seal and rotor increase, reducing sealing effectiveness
Solution Approach 1:
The seal shoes are made movable relative to the stator structure through spring elements, allowing the seal assembly to dynamically adapt to asymmetric deflection and clearance variations between rotor and stator, maintaining sealing effectiveness despite manufacturing tolerances
Solution Approach 2:
The spring elements enable the seal shoes to change their position and orientation in response to varying clearance conditions, transforming the rigid fixed-position seal into a flexible adaptive seal that compensates for manufacturing precision limitations
2Stability of the object's composition
If seal components are made rigid to maintain structural stability, then buckling resistance is improved, but vulnerability to buckling from circumferential loads increases
Solution Approach 1:
The seal shoes are designed as flexible components that can deflect under circumferential loads, using controlled flexibility to prevent buckling while maintaining structural integrity, rather than relying on rigid structures that are susceptible to buckling failure
Solution Approach 2:
The spring elements provide dynamic support to the seal shoes, allowing them to flex and absorb circumferential loads without buckling, transforming the static rigid structure into a dynamic system that adapts to applied loads
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 solution effectively seals annular gaps between stator and rotor structures by minimizing deflection and buckling, enhancing sealing performance and reliability through the use of spring elements and shoe support structures.
Implementation Method 1
Each of the plurality of spring elements extend radially between a respective seal shoe of the plurality of seal shoes and the seal base
Data Source
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AI summary
An outer seal structure for a rotor assembly includes a stator structure (24) and a non-contact seal assembly (40). The non-contact seal assembly (40) is fixed relative to the stator structure (24) and includes a plurality of seal shoes (54), a seal base (52), a plurality of spring elements (56), and a shoe support plate (150). The plurality of seal shoes (54) are arranged about an axis (22) in an annular array. The seal base (52) circumscribes the annular array of the plurality of seal shoes (54). Each of the plurality of spring elements (56) extend radially between a respective seal shoe (54) of the plurality of seal shoes (54) and the seal base (52). The shoe support plate (150) is arranged about the axis (22) and mounted to the stator structure (24) and includes a plurality of shoe support tabs (160) extending axially from the shoe support plate (150). Each shoe support tab (160) of the plurality of shoe support tabs (160) is disposed between each seal shoe (54).