Radial Seal Ring Profiling for Lower Contact Pressure
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Solution Overview
Problem
Traditional radial seal arrangements in gas turbine engines experience elevated wear and air leakage due to incorrect pre-profile assumptions, leading to increased contact pressure and reduced contact area, compromising seal performance and reliability.
Innovation Solution
A seal assembly with rotationally stationary seal rings having axially extending inner radial surfaces designed based on thermo-structural analysis to match the predicted shape of the rotating seal runner's outer radial surface at operating conditions, ensuring optimal contact area and reduced wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional pre-profile methods are used on the radial inner diameter sealing surface, then manufacturing is simpler, but operational contact pressure increases and contact area decreases
Solution Approach 1:
The seal ring inner radial surface is pre-profiled with a specific axially extending shape (convex, concave, or linear) before installation. This preliminary shaping of the sealing surface ensures that when the seal operates at running temperature, the contact area is maximized and contact pressure is optimized, preventing excessive wear and distortion of the seal runner.
Solution Approach 2:
The patent changes the geometric parameters of the seal ring inner radial surface by introducing specific axially extending shapes (convex, concave, or linear profiles). These parameter changes in the surface geometry compensate for thermal and structural deflections that occur during operation, maintaining optimal contact conditions between the seal ring and seal runner.
2Ease of manufacture
If traditional pre-profile methods are used, then manufacturing is easier, but seal wear increases and service life decreases
Solution Approach 1:
The seal ring inner radial surface is pre-profiled with a specific axially extending shape (convex, concave, or linear) before installation. This preliminary shaping of the sealing surface ensures that when the seal operates at running temperature, the contact area is maximized and contact pressure is optimized, preventing excessive wear and distortion of the seal runner.
Solution Approach 2:
The patent changes the geometric parameters of the seal ring inner radial surface by introducing specific axially extending shapes (convex, concave, or linear profiles). These parameter changes in the surface geometry compensate for thermal and structural deflections that occur during operation, maintaining optimal contact conditions between the seal ring and seal runner.
3Device complexity
If incorrect pre-profile assumptions are made, then design is simpler, but air leakage increases and bearing compartment oil containment is compromised
Solution Approach 1:
The seal ring inner radial surface is pre-profiled with a specific axially extending shape (convex, concave, or linear) before installation. This preliminary shaping of the sealing surface ensures that when the seal operates at running temperature, the contact area is maximized and contact pressure is optimized, preventing excessive wear and distortion of the seal runner.
Solution Approach 2:
The patent changes the geometric parameters of the seal ring inner radial surface by introducing specific axially extending shapes (convex, concave, or linear profiles). These parameter changes in the surface geometry compensate for thermal and structural deflections that occur during operation, maintaining optimal contact conditions between the seal ring and seal runner.
Data Source
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AI summary
A seal assembly (70) includes a rotating seal runner (74) having an outer radial surface (80), and one or more rotationally stationary seal rings (76) located radially outboard of the seal runner (74). Each seal ring (76) has an inner radial surface (82), with the inner radial surface (82) and the outer radial surface (80) defining a sealing interface (84) therebetween. An axially extending shape (94) of the inner radial surface (82) is selected utilizing a predicted shape (90) of the outer radial surface (80) at a selected operating condition of the seal assembly (70).