Vacuum Chamber Encapsulation with Flexible Intermediate Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage switching devices with vacuum chambers face issues of flashovers and reduced service life due to inadequate adhesion of silicone coatings, leading to mechanical stresses and insulation failures, particularly at higher voltages.
Innovation Solution
A high-voltage switching device with a cast housing made of casting resin, featuring an intermediate layer with a glass transition temperature between 10 and 40 °C, providing enhanced adhesion and flexibility to prevent flashovers, and a plastic body for improved sealing and production simplicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the vacuum chamber components expand due to heat from current flow, then power loss is released as heat, but mechanical stresses cause fine cracks in the solid plastic encapsulation
Solution Approach 1:
The solid plastic encapsulation is replaced with a flexible silicone coating that can accommodate thermal expansion of the vacuum chamber components without cracking. The elastomeric nature of the silicone allows it to stretch and deform elastically, maintaining encapsulation integrity while heat is dissipated during operation.
Solution Approach 2:
The material properties of the encapsulation are changed from rigid plastic to elastomeric silicone, fundamentally altering the mechanical behavior. The new material has higher elasticity and can withstand repeated thermal cycling and expansion without developing cracks, thus preserving structural integrity under thermal stress.
2Strength
If a rigid solid plastic encapsulation is used to enclose the vacuum chamber, then structural support is provided, but thermal expansion differences cause mechanical stresses and cracks
Solution Approach 1:
The rigid solid plastic encapsulation is replaced with a flexible silicone coating that provides both structural support and thermal expansion accommodation. The elastomeric silicone film maintains the necessary mechanical strength while allowing differential thermal expansion between the vacuum chamber components and the encapsulation material.
Solution Approach 2:
The design explicitly accounts for thermal expansion by using a material (silicone) whose coefficient of thermal expansion is better matched to the vacuum chamber components and that can elastically deform to accommodate expansion differences. This prevents the buildup of mechanical stresses that would lead to cracking.
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 prevents flashovers and mechanical stresses, ensuring reliable operation and extended service life by enhancing the adhesion of the intermediate layer to the vacuum chamber and providing a flexible, durable encapsulation.
Implementation Method 1
an intermediate layer (3A) being provided between the inner wall of the potted housing and the outer wall of the housing body (3) of the vacuum chamber, wherein the intermediate layer (3A) is a cast resin layer, with the glass transition temperature of the cast resin layer being between 10 and 40 °C
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a high-voltage switchgear with a vacuum chamber and a switchgear assembly with a high-voltage switchgear. Furthermore, the invention relates to a method for manufacturing a high-voltage switchgear with a vacuum chamber. The high-voltage switchgear has a potting housing 1 made of a casting resin, which encloses the housing body 3 of the vacuum chamber 2, which has a fixed contact 4A and a movable contact 5A, wherein an intermediate layer 3A is provided between the inner wall of the potting housing 1 and the outer wall of the housing body 3 of the vacuum chamber 2. The high-voltage switchgear is characterized in that this intermediate layer is a casting resin layer 3A, wherein the glass transition temperature of the casting resin layer is between 10 and 40 °C.In tests with such a setup, no cracks were found in the coating or covering of the vacuum chamber housing body, and no external flashovers were observed on the housing body.