Vacuum Pump Flange Connection With Wedge Force Transmission

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Solution Overview

Problem

Existing vacuum pump arrangements in mass spectrometers face a contradiction between the need for compact dimensions, which restricts accessibility, and the requirement for easy maintenance of roller bearings, leading to complex and costly designs with multiple seals and housing components.

Innovation Solution

A force transmission structure that converts a planar input force into axial contact pressure, allowing for vacuum-tight connection and easy assembly/disassembly of the vacuum pump from one side, using expanding elements with wedge surfaces and a lever mechanism to generate contact pressure without direct accessibility, and incorporating a damping element for reduced vibration transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the vacuum pump is positioned in the end device to achieve compact dimensions, then the overall system size is reduced, but the accessibility for maintenance is significantly restricted

Engineering Contradiction:
Improveoverall system sizeVSAvoidaccessibility for maintenance
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The vacuum pump assembly is segmented into a modular unit with a double housing structure. The inner housing contains the rotor, stator, and bearing assembly, while the outer housing provides structural support and mounting interfaces. This segmentation allows the pump to be installed in compact positions while maintaining accessibility through the outer housing's service ports.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A force transmission structure acts as an intermediary between the mounting flange and the vacuum pump housing. This structure transmits assembly forces from accessible external points to the internal components, enabling maintenance operations without requiring direct access to the pump's interior during normal operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a double housing structure is used to enable easy service, then accessibility for maintenance is improved, but the construction becomes very complex with additional housing components

Engineering Contradiction:
Improveaccessibility for maintenanceVSAvoidhousing structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The mounting flange is merged with the outer housing structure, eliminating the need for separate mounting brackets or additional fastening components. The flange serves dual purposes: structural attachment to the chamber and providing access points for force transmission during assembly and maintenance operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The outer housing serves multiple functions: it provides structural support, contains the inner housing assembly, provides mounting interfaces via the flange, and facilitates maintenance access through integrated service ports. This multi-functionality reduces the need for additional specialized components.

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

3Reliability

If multiple seals are added to ensure vacuum-tight connection, then the vacuum tightness is improved, but manufacturing costs are driven up

Engineering Contradiction:
Improvevacuum tightnessVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

A flexible sealing lip is used at the interface between the inner and outer housings. This single flexible seal provides vacuum-tight sealing while accommodating minor misalignments and thermal expansion, replacing what would otherwise require multiple rigid seals and increasing manufacturing complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The flange connection uses a composite sealing structure combining rigid flange materials with flexible sealing elements. This composite approach achieves reliable vacuum tightness through material properties rather than through multiple separate sealing components, reducing manufacturing cost.

Inventive Principle:
Principle #40Composite materials

4Ease of operation

If a force transmission structure is used to generate contact pressure, then assembly ease is improved, but additional structural components are required

Engineering Contradiction:
Improveassembly easeVSAvoidforce transmission structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The force transmission structure incorporates dynamic elements that automatically adjust contact pressure based on assembly forces. Wedge-shaped surfaces convert axial assembly forces into radial clamping forces, and spring elements provide continuous contact pressure compensation, eliminating the need for complex adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The force transmission structure changes the mechanical parameters of force transmission through wedge angles and leverage ratios. By optimizing these geometric parameters, the structure achieves effective contact pressure generation with minimal additional components, transforming simple axial assembly forces into sufficient radial clamping forces.

Inventive Principle:
Principle #35Parameter changes

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 solution enables cost-effective assembly and maintenance of vacuum pumps with reduced manufacturing costs and improved vibration resistance, suitable for compact and sensitive applications.

Implementation Method 1

The arrangement has a force transmission structure which transmits a force from a point of introduction to at least one point of action lying elsewhere in the flange connection

Methodology Applied
Scientific EffectForce transmission: Mechanical Force

Implementation Method 2

In a further development, the spreading elements have wedge surfaces that are in contact with one another

Methodology Applied
Scientific EffectWedge mechanism: Wedge

Implementation Method 3

A damping element in the power transmission structure ensures reduced vibration transmission via the flange connection

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP2228540B1Assembly with vacuum pump
Publication Date: 2016.08.03 PFEIFFER VACUUM GMBH
  • EP2228540B1 patent drawingFigure 1
  • EP2228540B1 patent drawingFigure 2~3
  • EP2228540B1 patent drawingFigure 4~5

AI summary

The arrangement has a vacuum pump provided with a pump flange (10), and a chamber with a chamber flange (20). A flange connection comprising the pump flange and chamber flange is provided for a vacuum-tight connection of the chamber and the vacuum pump. A force transferring structure (65) transfers force from an introduction point (56) to an effective point (59) lying in the flange connection. The pump flange has two suction openings that are connected with a pumping stage. The force transferring structure has two bridging elements (52, 53) provided with wedge surfaces (58, 58').