Vacuum Pump Conductor Sealing for Glow Discharge Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vacuum devices face issues with glow discharges due to low pressures, which can lead to malfunctions and damage, especially when electric motors are involved and high voltages are used, as existing sealing methods are not effective in preventing corona discharges.
Innovation Solution
The solution involves shifting the seal between the vacuum and pressure areas closer to the functional unit, using a sealing body formed by a casting compound, such as plastic or glass, to encase the electrical conductor and prevent exposure to the vacuum area, thereby reducing the risk of glow discharges. This sealing body interacts with a housing element or additional seals like O-rings to create a secure seal within the pressure area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If connectors with potted contacts or circuit boards are used to seal between vacuum and pressure environments, then electrical connection is achieved, but glow discharges can still occur on conductors passing through the vacuum region
Solution Approach 1:
The patent extracts the conductor exit region from the vacuum environment by positioning it in the pressure region. The sealing element creates a barrier that confines the conductor's exit point to the pressure side, effectively removing the conductor from exposure to the vacuum region where glow discharges occur. This resolves the contradiction by maintaining electrical connection reliability while eliminating the harmful glow discharge effect.
Solution Approach 2:
The sealing element acts as an intermediary structure that bridges the vacuum and pressure environments while protecting the conductor. It provides a sealed passage that allows the conductor to transition from the vacuum region to the pressure region without exposing it to harmful conditions, thus maintaining both electrical connection and preventing glow discharges.
2Ease of manufacture
If the seal is positioned away from the functional unit, then assembly is easier, but conductors are exposed to vacuum pressure and glow discharges
Solution Approach 1:
Instead of positioning the seal away from the functional unit as in conventional designs, the patent inverts the approach by positioning the sealing element directly on the functional unit's outer surface. This reversal ensures that the conductor exit region is immediately protected from vacuum exposure, eliminating glow discharge risks while maintaining assembly feasibility through the integrated sealing design.
3Reliability
If cable insulation is used on conductors, then electrical protection is provided, but insulation imperfections still allow glow discharges at low pressures
Solution Approach 1:
The patent applies preliminary anti-action by preventing the conductor from entering the vacuum region in the first place. Rather than relying on cable insulation that may have defects, the sealing element creates a physical barrier that stops the conductor at the pressure region boundary. This proactive measure eliminates the possibility of glow discharges through insulation imperfections by removing the conductor from the low-pressure environment where such discharges occur.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a vacuum device, in particular a vacuum pump, with an electrically operable functional unit which is at least partially arranged in a vacuum region of the vacuum device and is connected to at least one electrical conductor which exits the functional unit at an outlet region and leads into a pressure region sealed against the vacuum region, wherein the outlet region is located within the pressure region.