Scroll Vacuum Pump Axial Gap Control Without Tip Seals
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Solution Overview
Problem
Scroll vacuum pumps with TipSeals face issues such as limited lifespan, abrasion, sensitivity to external influences, and require precise axial gap dimensions, leading to variable vacuum performance and increased maintenance.
Innovation Solution
Implementing an adjusting means to actively or passively influence thermal expansion and heat transfer within the pump, using materials with varying thermal conductivities, heating/cooling devices, and control systems to precisely set and maintain the axial gap between spiral components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TipSeals are used to seal the spiral components, then sealing performance is improved, but maintenance frequency increases and service life is limited
Solution Approach 1:
The patent removes the TipSeals from the system entirely, replacing them with a precision-machined axial gap structure. The sealing function is transferred from the consumable TipSeals to the precisely controlled clearance between the fixed and movable spiral components, eliminating the need for periodic replacement of sealing elements.
Solution Approach 2:
The mechanical contact-based sealing (TipSeals) is replaced with a non-contact precision clearance system. The axial gap dimension is precisely controlled through mechanical design and adjustment mechanisms, creating a seal through precision engineering rather than physical sealing elements.
2Reliability
If TipSeals are used for sealing, then vacuum performance is achieved, but vacuum stability deteriorates over time due to wear
Solution Approach 1:
By removing the TipSeals that are subject to wear, the patent eliminates the source of performance degradation over time. The precision axial gap structure maintains consistent sealing characteristics without the wear mechanisms that affect TipSeals, ensuring stable vacuum performance throughout the pump's operational life.
Solution Approach 2:
The patent incorporates an adjustment mechanism that allows the axial gap dimension to be dynamically optimized. This enables compensation for thermal expansion and operational changes, maintaining precise sealing clearance and consistent vacuum performance under varying operating conditions.
3Reliability
If precise axial gap dimension is maintained, then vacuum performance is improved, but device complexity increases due to adjustment mechanisms
Solution Approach 1:
The patent focuses on precisely controlling a single critical parameter - the axial gap dimension. By concentrating design efforts on optimizing this one parameter through a relatively simple adjustment mechanism (such as adjustable spacers or threaded adjustments), the patent achieves high vacuum performance without introducing excessive complexity across the entire system.
4Productivity
If axial gap dimension is precisely controlled, then productivity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent incorporates adjustment mechanisms that allow the axial gap to be set and optimized after assembly. This preliminary adjustment capability compensates for normal manufacturing tolerances, enabling precise axial gap control without requiring extremely tight machining tolerances on all components. The adjustment is performed as a preliminary step before final operation.
Data Source
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AI summary
Scroll vacuum pump with a pumping system (11, 13) comprising a stationary spiral component (11) and a movable spiral component (13) that interacts with it effectively for pumping, a drive shaft (17) rotating about a rotary axis (15) during operation with an eccentric section (19) for driving the movable spiral component (13), and an electric drive motor (21, 23) for the drive shaft (17), wherein an axial gap dimension is present between the two spiral components (11, 13), and wherein an adjusting means (113) is provided which is designed to adjust the axial gap dimension.