Split Flow Vacuum Pump Multi-Inlet Design

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Solution Overview

Problem

Existing split-flow vacuum pumps face challenges in increasing the number of inlets without adding more pump stages, which complicates manufacturing and increases costs due to the need for multiple rotor-stator packages and different disk sizes.

Innovation Solution

The design incorporates at least three radial main inlets between turbomolecular pump stages and an additional radial secondary inlet within a turbomolecular pump stage, allowing for more inlets over a shorter axial length, with the secondary inlets positioned between stator and rotor disks, enhancing the evacuation of multiple vacuum chambers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of rotor disk stacks is increased to incorporate more taps on split-flow vacuum pumps with high pumping speeds, then the number of inlets is increased, but manufacturing difficulties increase

Engineering Contradiction:
Improvenumber of inletsVSAvoidmanufacturing difficulties
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies universality by making all rotor disks have the same inner diameter, allowing a single type of rotor disk to serve multiple functions across different positions in the pump. This standardization enables the rotor disks to be universally interchangeable, simplifying manufacturing while still accommodating multiple inlets through strategic positioning between disks rather than requiring unique disks for each inlet location

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If many different disks with varying inner diameters are used to realize multiple disk packs with multiple axial stops on the shaft, then the number of inlets is increased, but manufacturing complexity increases

Engineering Contradiction:
Improvenumber of inletsVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies homogeneity by ensuring all rotor disks have the same inner diameter and identical geometry. This uniformity reduces manufacturing complexity by eliminating the need to produce multiple varieties of disks with different dimensions. The homogenized disk design simplifies inventory management, quality control, and assembly processes while maintaining the capability to support multiple inlets through the standardized disk configuration

Inventive Principle:
Principle #33Homogeneity

3Adaptability or versatility

If multiple vacuum pumps are equipped with their own flanges to evacuate multiple chambers, then each chamber can be evacuated independently, but the cost and space requirements increase

Engineering Contradiction:
Improveevacuation capabilityVSAvoidspace requirements
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent applies merging by combining multiple evacuation functions into a single vacuum pump unit. Instead of using separate pumps for different chambers, the invention integrates multiple inlets and rotor-stator assemblies within one pump housing, allowing simultaneous evacuation of multiple chambers. This consolidation reduces the overall space required, eliminates redundant components, and lowers system cost while maintaining independent evacuation capability for each chamber

Inventive Principle:
Principle #5Merging (Combining)

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 increases the number of inlets, enabling the evacuation of more chambers with a single pump over a shorter axial length, simplifying manufacturing by using fewer distinct disk sizes and reducing costs while maintaining high pumping capacity.

Implementation Method 1

at least two pumping stages are designed as turbomolecular pumping stages

Methodology Applied
Scientific EffectTurbomolecular pumping:

Data Source

PatentEP3112688B2Split flow vacuum pump and vacuum system with a split flow vacuum pump
Publication Date: 2022.05.11 PFEIFFER VACUUM GMBH
  • EP3112688B2 patent drawingFigure 1
  • EP3112688B2 patent drawingFigure 2
  • EP3112688B2 patent drawingFigure 3~4

AI summary

The invention relates to a split-flow vacuum pump (1) with at least three main inlets (23-26), in which at least one secondary inlet (27, 28) is additionally provided, which is arranged in the region of at least one turbomolecular pumping stage (21, 22). A split-flow vacuum pump is also provided with stator disks (20) and rotor disks (14-19) arranged on a shaft (13), wherein the shaft has at least two different outer diameters (29-32) and disk stacks have inner diameters adapted to the outer diameters of the shaft, in which, in addition to a region with a largest diameter (29), the shaft has at least two regions with smaller diameters (30, 31) on each side in the axial direction. The invention also relates to a split-flow vacuum pump (1) with a housing having at least two thermally decoupled housing regions.