Brush Seal Ring Interference Fit Thermal Expansion
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Solution Overview
Problem
Existing brush seal arrangements in turbomachines face challenges in maintaining precise positioning and sealing effectiveness due to thermal expansion differences between materials, leading to potential gaps and reduced efficiency.
Innovation Solution
A brush seal arrangement with a ring connected to the stator via an interference fit, utilizing materials with different coefficients of thermal expansion to ensure a secure frictional connection and prevent relative movement, combined with an axial locking mechanism for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ring is connected to the stator using a form-fitting connection (hooks, pins, or heels), then the brush seal can be securely fixed in place, but the structure becomes more complex and manufacturing becomes more difficult
Solution Approach 1:
The patent removes the complex form-fitting connection elements (hooks, pins, heels) from the brush seal assembly. Instead, it uses a simple interference fit between the ring and stator, combined with differential thermal expansion, to achieve secure fixation without additional structural complexity
Solution Approach 2:
The patent changes the physical parameters of the materials used - specifically selecting materials with different coefficients of thermal expansion (first material ≥10×10^-6/K, second material ≤10×10^-6/K). This parameter change enables the simple interference fit to maintain reliable connection under thermal conditions without complex structural features
2Stability of the object's composition
If materials with the same coefficient of thermal expansion are used for the ring and stator, then thermal expansion is uniform, but the interference fit becomes loose at elevated temperatures causing relative movement and reduced sealing effectiveness
Solution Approach 1:
The patent directly applies thermal expansion by selecting materials with different coefficients of thermal expansion. The first material (ring) has α1 ≥10×10^-6/K while the second material (stator) has α2 ≤10×10^-6/K. This ensures that at elevated temperatures, the ring expands more than the stator, maintaining and even strengthening the interference fit to prevent relative movement and maintain sealing effectiveness
Solution Approach 2:
The patent uses composite materials strategy by combining two different materials with specific thermal expansion properties in the brush seal assembly. This material selection strategy enables the interference fit to remain reliable under thermal conditions without requiring additional mechanical fastening elements
3Ease of operation
If traditional form-fitting connections are used to secure the brush seal, then positioning is achieved, but installation errors can occur and precision is reduced
Solution Approach 1:
The patent implements self-service through the differential thermal expansion mechanism. The materials automatically adjust the interference fit according to temperature changes, self-regulating the connection strength without requiring precise manual installation or additional positioning features. This eliminates installation errors while maintaining precision
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 enhances the sealing efficiency by maintaining a consistent frictional connection despite thermal changes and prevents incorrect installation, thereby improving turbomachine performance and reducing manufacturing costs.
Implementation Method 1
The first material has a first coefficient of thermal expansion (α1) of greater than or equal to 10×10 -6 per Kelvin in a temperature range between at least 20 degrees Celsius and 400 degrees Celsius. The second material has a second coefficient of thermal expansion (α2) of less than or equal to 10×10 -6 per Kelvin in a temperature range between at least 20 degrees Celsius and 90 degrees Celsius.
Data Source
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AI summary
The present invention relates to a brush seal assembly (100) for a turbomachine, comprising at least one stator, one rotor (2), and a brush seal (15), wherein the brush seal (15) comprises at least one brush element (13) and a ring for receiving the brush element (13), and wherein the brush seal assembly (100) seals a gap (11) between the stator and the rotor (2). The ring is connected to the stator by means of an interference fit. The ring has a first material with a first coefficient of thermal expansion (α1), wherein at least one section of the stator for receiving the ring has a second material with a second coefficient of thermal expansion (α2). The present invention further relates to a mounting locking arrangement and a turbomachine.