Vacuum Pump Gas-Lubricated Face Seal
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Solution Overview
Problem
Vacuum pumps face challenges in maintaining high vacuum quality due to foreign matter and corrosive gases exchanging between the working and storage spaces, leading to contamination, damage, and increased maintenance costs, with existing seals causing wear and reducing efficiency.
Innovation Solution
A gas-lubricated face seal is implemented between the rotor shaft and partition, using a pair of slide rings and a mating ring with spring loading, creating a non-contact seal with an air cushion, preventing fluid exchange and maintaining vacuum quality independently of speed and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shaft sealing rings or lip seals are used to separate the working space and storage space, then gas-tight separation is achieved, but the seals are subject to high wear and reduce energy efficiency
Solution Approach 1:
The patent replaces traditional mechanical contact seals (shaft sealing rings, lip seals) with a magnetic coupling system that transfers rotational motion through magnetic fields without physical contact. This eliminates mechanical wear and the associated energy losses while maintaining gas-tight separation between the working and storage spaces.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the working space and storage space to transmit rotational motion. The magnetic coupling acts as a mediator that allows power transmission without direct mechanical contact, thereby preventing wear and maintaining sealing integrity.
2Reliability
If the storage space is evacuated along with the working space, then vacuum is created, but heat dissipation from bearings and gears becomes insufficient
Solution Approach 1:
The patent segments the internal environment into two distinct pressure zones: the working space maintained at vacuum conditions and the storage space maintained at atmospheric pressure. This segmentation allows the storage space to contain air for effective heat dissipation from bearings and gears, while the working space maintains the required vacuum for process operations.
3Productivity
If corrosive gases from the working space enter the storage space, then pump operation continues, but bearings and gears suffer damage and premature failure
Solution Approach 1:
The magnetic coupling acts as an intermediary barrier that allows power transmission while preventing the passage of corrosive gases from the working space into the storage space. The magnetic field transfers rotational motion without requiring any physical opening or seal penetration, thereby protecting bearings and gears from corrosion while maintaining continuous pump operation.
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 achieves a reliable, wear-free, and loss-free seal, enhancing vacuum quality and operational reliability by preventing fluid exchange and ensuring effective heat dissipation in the storage space.
Implementation Method 1
the shaft seal being designed as a gas-lubricated face seal
Implementation Method 2
a lubricating gas flowing through the sealing gap creating an air cushion between the sealing surfaces
Implementation Method 3
mounted with springs on the rotating or on the static component to be sealed against one another
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a vacuum pump, in particular a screw pump or a single-stage or multi-stage rotary lobe pump, comprising a working chamber, a bearing chamber, a partition wall arranged between the working chamber and the bearing chamber, at least one rotor shaft extending through the partition wall, and a shaft seal for sealing between the rotor shaft and the partition wall. The shaft seal is designed as a gas-lubricated mechanical seal.