Turbomolecular Vacuum Pump Holweck Stage Axial Gap Optimization
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Solution Overview
Problem
Conventional turbomolecular vacuum pumps with Holweck stages have high power consumption due to gas friction, which is not efficiently managed without compromising pumping speed or fore-vacuum compatibility.
Innovation Solution
Increasing the axial distance between Holweck stator segments and the rotor hub, while reducing the axial extent of the Holweck stator segments, to create a larger axial gap, thereby reducing power consumption without significantly affecting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the axial distance between Holweck stator segments and rotor hub is increased, then power consumption is reduced, but pumping speed and fore-vacuum compatibility may be compromised
Solution Approach 1:
The patent applies parameter changes by modifying the axial distance parameter between Holweck stator segments and rotor hub. Specifically, the axial distance is increased to greater than 25% of the axial extension of the Holweck stator segments or Holweck sleeves, which fundamentally changes the geometric parameter to reduce gas friction and power consumption while maintaining pumping performance through optimized configuration
2Loss of energy
If the axial distance between Holweck stator segments and rotor hub is increased, then power consumption is reduced, but fore-vacuum compatibility may be affected
Solution Approach 1:
The patent changes the axial distance parameter to greater than 25% of the axial extension of the Holweck stator segments or sleeves, which reduces gas friction and power consumption. This parameter change is specifically designed to maintain fore-vacuum compatibility by preserving the necessary pressure differential and flow characteristics through optimized geometric configuration
3Loss of energy
If the axial extent of Holweck stator segments is reduced, then axial distance is increased, but pumping active area is decreased
Solution Approach 1:
The patent changes the axial extent parameter of the Holweck stator segments to be less than 75% of the axial extension of the Holweck sleeves, which creates the necessary axial distance for reduced power consumption. This parameter modification is optimized to maintain sufficient pumping active area through the remaining effective length and cross-sectional area of the stator segments
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 significantly reduces power consumption while maintaining comparable performance, with a disproportionate positive effect on power savings and minimal impact on vacuum data.
Implementation Method 1
generates molecular flow through the rotation of a rotating element relative to a static element
Implementation Method 2
a large part of the power consumption is often caused by the gas friction in the Holweck stage(s)
Data Source
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AI summary
The present invention relates to a vacuum pump, in particular a turbomolecular vacuum pump, with at least one inlet, one outlet, and at least two Holweck stages arranged concentrically with respect to a common axis of rotation and successively in the pumping direction between the inlet and the outlet, each comprising a Holweck stator segment with a Holweck thread and a Holweck sleeve rotating about the axis of rotation, wherein the Holweck stator segments are each arranged on one side of a common Holweck stator projecting into a radial space between the concentrically arranged Holweck sleeves, which are attached to a Holweck hub non-rotatably connected to a rotor of the vacuum pump. An axial distance between an axial end of at least one of the Holweck stator segments projecting into the radial space and the Holweck hub is greater than 25% of the axial extent of a section of the Holweck stator segment projecting into the radial space.Alternatively or additionally, the axial distance is greater than 25% of the axial extent of at least one of the Holweck sleeves and/or an axial extent of a section projecting into the radial space of at least one of the Holweck stator segments is less than 75% of the axial extent of at least one of the Holweck sleeves.