Power Bushing Sealing Arrangement for Thermal Movement and Oil Tightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sealing arrangements for high voltage transformer bushings are inadequate in addressing thermal expansion and contraction issues, leading to wear and potential oil leakage, and are either too simple or excessively complex, increasing costs and complexity.
Innovation Solution
A sealing arrangement featuring a guide element with a cylinder and flange portion, a static sealing structure between the guide element and top cover, and a dynamic sealing structure with O-rings and a wear ring between the guide element and central conductor, utilizing materials like fluorine silicone rubber and polytetrafluoroethylene, along with a protective cap to prevent external damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple dynamic sealing system is used, then the device complexity is reduced, but the sealing reliability deteriorates due to insufficient protection against thermal expansion and contraction
Solution Approach 1:
The sealing system is divided into two independent segments: a static sealing structure (sealing ring) between the guide element and top cover, and a dynamic sealing structure (dynamic sealing ring) between the guide element and central conductor. This segmentation allows each sealing element to perform its specific function optimally - the static seal handles fixed sealing points while the dynamic seal accommodates thermal movement, thereby improving overall sealing reliability without excessive complexity.
Solution Approach 2:
The guide element serves as an intermediary component that mediates between the fixed top cover and the thermally expanding/contracting central conductor. It provides a stable mounting structure for both static and dynamic sealing elements while allowing the central conductor to move freely during thermal cycles, thus protecting the sealing structures from direct mechanical stress and improving sealing reliability.
2Reliability
If a multi-contact and static system is applied, then the sealing reliability is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The sealing system incorporates both static and dynamic sealing elements. The dynamic sealing ring specifically addresses the thermal expansion and contraction of the central conductor by allowing relative movement while maintaining sealing integrity. This dynamic approach replaces the need for complex multi-contact static systems, achieving reliable sealing with reduced complexity by matching the sealing strategy to the actual movement requirements.
3Device complexity
If no protective cap is used, then the device complexity is reduced, but the sealing elements are exposed to external environmental damage
Solution Approach 1:
The protective cap is installed beforehand to shield the sealing elements (both static and dynamic sealing rings) from external environmental factors such as dust, moisture, and chemical corrosion. This preventive protection ensures the sealing elements maintain their integrity and sealing performance throughout the service life, avoiding premature failure due to environmental degradation without adding significant structural complexity.
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 provides effective sealing performance, prevents eccentricity and wear, and protects against electrochemical corrosion, maintaining tightness under varying temperatures and external conditions without significant cost or complexity increase.
Implementation Method 1
a dynamic sealing structure provided between the guide element and the central conductor... at least one dynamic sealing O-ring between the guide element and the central conductor
Implementation Method 2
the dynamic sealing structure may further comprise a wear ring arranged between the guide element and the central conductor... the wear ring may be made of poly tetra fluoroethylene
Implementation Method 3
a static sealing structure provided between the guide element and the top cover
Implementation Method 4
protective cap covering a top portion of the guide element to protect the sealing arrangement from an external environment
Data Source
AI summary
Embodiments of the present disclosure relate to a sealing arrangement of a bushing for a power electrical device and a bushing comprising the sealing arrangement. The sealing arrangement includes a top cover; a central conductor going through the top cover; a guide element having a cylinder portion and a flange portion extended from a middle part of the cylinder portion, wherein the cylinder portion is arranged between the top cover and the central conductor, and the flange portion is connected onto the top cover; a static sealing structure provided between the guide element and the top cover; and a dynamic sealing structure provided between the guide element and the central conductor. With the new sealing structure design, it could provide a good sealing performance so that the bushing can be used in various environments.