Siegbahn-Holweck Vacuum Pump for Back Pressure Control
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Solution Overview
Problem
Existing turbomolecular pumps face challenges in achieving optimal exhaust performance, particularly in terms of back pressure characteristic, which is influenced by the length of the gas flow passage, and there is a need for improved designs to enhance this aspect.
Innovation Solution
The vacuum pump incorporates a Siegbahn exhaust mechanism with spiral grooves on rotating and stator discs, and a Holweck exhaust mechanism with constant flow passage depth, arranged in multiple stages, including a rotor blade and stator blade configuration to improve exhaust efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the flow passage length is increased to improve back pressure characteristic, then the back pressure characteristic is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The exhaust mechanism is divided into two distinct segments: a Siegbahn exhaust mechanism with spiral grooves and a Holweck exhaust mechanism with helical grooves. Each segment handles gas flow in a different manner, allowing the system to achieve improved back pressure characteristics without requiring a single excessively long and complex flow passage. The segmentation enables modular design and simplifies manufacturing while maintaining performance.
Solution Approach 2:
The invention transitions from a single-type exhaust mechanism to a two-stage configuration combining Siegbahn and Holweck mechanisms. This dimensional change in the exhaust mechanism architecture allows gas to be exhausted through multiple pathways with different flow characteristics, achieving superior back pressure performance without proportionally increasing flow passage length or complexity.
2Productivity
If a single-type exhaust mechanism is used, then the device complexity is reduced, but the exhaust performance is insufficient
Solution Approach 1:
The invention merges two different exhaust mechanisms - the Siegbahn type with spiral grooves that provide directivity for gas molecules, and the Holweck type with helical grooves that transport gas through a different flow pattern. This combination allows the system to leverage the strengths of both mechanisms, achieving superior exhaust performance that neither mechanism could provide alone, while maintaining a compact integrated structure.
Solution Approach 2:
The dual-stage exhaust mechanism provides multi-functionality: the Siegbahn mechanism handles initial gas compression and directional flow, while the Holweck mechanism provides secondary compression and exhaust. This universal design allows a single pump to effectively handle various gas types and flow conditions, enhancing overall exhaust performance without requiring multiple separate devices.
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 design provides a vacuum pump with enhanced exhaust performance by optimizing gas flow and reducing back pressure, resulting in improved operational efficiency and reliability.
Implementation Method 1
a motor in a pump main body is energized to rotate rotor blades, which hit gaseous molecules of gas (process gas) drawn into the pump main body, thereby exhausting the gas
Implementation Method 2
the rotating disc imparts tangential momentum to gas molecules dispersed in the spiral groove flow passages, and the spiral groove flow passages provide directivity such that the molecules tend to flow in an exhaust direction to be exhausted
Data Source
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AI summary
A vacuum pump having excellent exhaust performance is provided. The vacuum pump includes a Siegbahn type exhaust mechanism portion 201 in which a Siegbahn spiral groove portion 262 is provided in at least either rotating discs 220a to 220c or stator discs 219a and 219b, and a Holweck type exhaust mechanism portion 301 in which a thread groove 131a is provided in at least either a cylindrical portion 102d of a rotating body 103 or a threaded spacer 131, and the Holweck type exhaust mechanism portion 301 is located on the downstream side of the Siegbahn type exhaust mechanism portion 201. The Holweck type exhaust mechanism portion 301 has a flow passage depth that is continuously constant at a predetermined depth H2, and the Siegbahn type exhaust mechanism portion 201 includes a region that is continuously constant at the predetermined depth H2 from a predetermined position.