Lubricant-Sealed Vacuum Pump Additional Seal for Particle Filtration
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Solution Overview
Problem
Lubricant-sealed vacuum pumps, such as rotary vane pumps, face issues with seal leakage due to particle intrusion, which reduces the useful life of the shaft seals, even with high-quality seals.
Innovation Solution
The implementation of an additional seal with a filtering effect, comprising a sealing lip made of textile fiber or non-woven materials, positioned between the main seal and the shaft, along with a collection chamber and conveying element to manage lubricant and prevent leakage, enhances the sealing tightness and extends the seal's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a main seal with sealing lip is provided on the shaft, then sealing tightness is improved, but particles can still intrude into the seal area causing leakage
Solution Approach 1:
The seal system is divided into two separate seals: a main seal (32) with a sealing lip for primary sealing, and an additional seal (44) with a sealing lip made of filtering material for particle retention. This segmentation allows each seal to specialize in one function, resolving the contradiction between sealing tightness and particle protection.
Solution Approach 2:
The additional seal acts as an intermediary element between the suction chamber and the main seal. It filters particles from the lubricant before they can reach the main seal, thereby protecting the main seal while maintaining sealing effectiveness.
2Reliability
If the sealing lip of the main seal is made from softer material for better sealing, then sealing effect is improved, but the seal becomes more vulnerable to particle damage
Solution Approach 1:
The sealing function is segmented between two seals with different material properties. The main seal uses softer material (Viton, FKM, FPM, PTFE, or EPDM) optimized for sealing contact, while the additional seal uses filtering material (textile fiber or non-woven textile) optimized for particle retention, eliminating the need to compromise material selection.
Solution Approach 2:
The additional seal is positioned beforehand to intercept and retain particles in the lubricant, cushioning the main seal against particle damage before particles can reach it. This protective barrier allows the main seal to use softer, more compliant materials without fear of particle-induced failure.
3Object-affected harmful factors
If an additional seal is added to filter particles, then particle retention is improved, but device complexity increases
Solution Approach 1:
The additional seal serves multiple functions simultaneously: it acts as a filter to retain particles, provides an additional sealing barrier, and protects the main seal from particle damage. This multi-functionality justifies the added component by consolidating multiple protective roles into a single element.
4Reliability
If high-quality seals are used, then initial sealing tightness is improved, but leakage occurs after many hours of use due to particle intrusion
Solution Approach 1:
The additional seal with filtering material is positioned beforehand to intercept and retain particles in the lubricant, preventing them from reaching and damaging the main seal. This prior protection extends the operational life of the main seal by eliminating the primary cause of seal failure over time.
Solution Approach 2:
The sealing system is segmented into a main seal for primary sealing and an additional seal for particle filtration. This segmentation allows the main seal to maintain its high-quality sealing properties while the additional seal absorbs the particle damage, thereby extending the overall system lifespan.
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 additional seal effectively filters out particles and manages lubricant leakage, significantly improving the sealing tightness and extending the operational life of the shaft seals in vacuum pumps.
Implementation Method 1
The additional seal serves as a kind of filter preventing the transport of particles in the direction of the main seal
Implementation Method 2
both seals comprise a sealing lip arranged in abutment on the shaft surface or on the outer side of the shell
Implementation Method 3
the lubricant will be supplied to the recesses of the rotor in which the sliding vanes are held for radial displacement. Under the effect of the centrifugal forces, the lubricant will then reach the outer edge of the sliding vane
Data Source
Figure 1~3
AI summary
A lubricant-sealed vacuum pump, such as a rotary vane pump, comprises a rotor element (16) arranged in a suction chamber (10). The rotor element (16) is carried by a rotor shaft (26). The shaft (26) is surrounded by a main seal (32) arranged in the pump housing (12). In addition to the main seal (32), an additional seal (44) is arranged on an inner side (42) of the main seal (32). The additional seal (44) comprises a sealing lip (50) arranged on an outer side (36) of a shell (30).