Linked Screw Groove Spacer for Compact Vacuum Pump Compression
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Solution Overview
Problem
Existing vacuum pumps, such as Siegbahn and thread groove pumps, face challenges in downsizing while maintaining exhaust performance, as increasing the number of stages or thread length leads to increased pump size and manufacturing costs.
Innovation Solution
A connected thread groove spacer is introduced, integrating a Siegbahn portion with a thread groove portion to form a right-angle flow channel connection, allowing for a reduction in the height of the thread groove pump portion while maintaining exhaust performance by connecting the Siegbahn and thread groove portions, which are configured to have spiral and thread grooves respectively, and are formed integrally to reduce the axial length of the pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of stages of discs is increased to improve compression performance, then the compression ratio is improved, but the size of the pump increases
Solution Approach 1:
The patent combines the Siegbahn pump portion and thread groove pump portion into a single integrated pump body, merging two different pumping mechanisms into one unified structure. This allows the pump to achieve high compression performance through the combined action of both portions without requiring multiple separate stages, thereby avoiding an increase in overall pump size.
Solution Approach 2:
The patent utilizes the radial dimension by forming the thread groove portion on the inner circumferential surface of the rotor cylindrical portion, creating a parallel flow path that extends in the radial direction rather than only in the axial direction. This dimensional change allows for increased compression performance without proportionally increasing the axial length of the pump.
2Reliability
If the thread length is increased to improve compression performance, then the compression ratio is improved, but the size of the casing increases
Solution Approach 1:
The patent transitions from increasing axial length to utilizing radial space by forming thread grooves on the inner circumferential surface of the rotor cylindrical portion. The thread groove portion extends in the radial direction within the rotor, allowing for effective compression path lengthening without increasing the axial length of the casing.
Solution Approach 2:
The thread groove portion is nested within the rotor cylindrical portion, with the thread grooves formed on the inner circumferential surface. This nested configuration allows the compression mechanism to be contained within the existing rotor structure, avoiding the need to increase the overall casing dimensions.
3Reliability
If parallel paths are configured to improve compression performance, then the compression ratio is improved, but the number of parts and manufacturing cost increase
Solution Approach 1:
The patent merges the Siegbahn pump portion and thread groove pump portion into a single integrated pump body with unified drive mechanisms. The rotor and stator assemblies share common structural elements and mounting features, reducing the total number of separate parts compared to having completely separate parallel pump systems.
Solution Approach 2:
The rotor cylindrical portion serves multiple functions: it acts as the rotating element for the thread groove pump portion, provides structural support for the pump body, and defines the flow path geometry. This multi-functionality reduces the need for additional dedicated components, thereby simplifying the overall device structure.
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
This configuration allows for a reduction in the overall size of the vacuum pump while maintaining high exhaust performance, thereby reducing manufacturing costs and achieving a more compact design.
Implementation Method 1
gas molecules diffusing inside and entering the spiral grooved flow channel
Implementation Method 2
give momentum in the tangential direction of the rotating disk to gas molecules
Data Source
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AI summary
Provided are a connected thread groove spacer for realizing downsizing of a thread groove pump portion while keeping the exhaust performance, and a vacuum pump in which the connected thread groove spacer is provided. The connected thread groove spacer according to an embodiment of the present invention has a structure that connects a Siegbahn pump portion and a thread groove pump portion. More specifically, the thread groove pump portion, which is an exhaust element, is structured such that a Siegbahn structure is attached onto a cylindrical thread, and such that respective parts are connected to each other at this attachment section. In other words, a flow channel of the Siegbahn portion and a flow channel of the cylindrical thread (the thread groove pump portion) are connected to each other so as to substantially form a right angle when viewed from an axis direction of the vacuum pump, thus, the flow channel of the Siegbahn portion and the flow channel of the thread groove pump portion are connected to each other. According to this configuration, the length of a compression flow channel of the thread groove pump portion can be increased in a radial direction due to the connected Siegbahn portion.