Vacuum Pump Rotor Anti-Twist Projection

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Solution Overview

Problem

Existing vacuum pump designs face issues with rotor twisting due to frictional engagement, leading to loosening and potential pump failure, and previous solutions either complicate assembly or increase costs with complex fastening systems and precise component alignment.

Innovation Solution

A vacuum pump with a centrally arranged fastening element and an anti-twist device featuring a projection that causes plastic deformation on contact surfaces between the rotor and rotor shaft, preventing rotation and ensuring secure attachment without the need for complex assembly or high-quality components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a friction-based connection between rotor and shaft is used, then assembly is simple, but the rotor can twist and loosen under overload

Engineering Contradiction:
Improveassembly simplicityVSAvoidconnection security
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The projection on the rotor shaft creates a preliminary form-fit connection that prevents twisting before the friction-based fastening element is fully engaged. This preliminary mechanical interlocking ensures that even under overload, the rotor cannot twist relative to the shaft, while still allowing simple assembly through the friction mechanism.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple screws with form-fitting connection are used to prevent rotor twisting, then reliability improves, but assembly becomes complex and cost increases

Engineering Contradiction:
Improveanti-twist securityVSAvoidfastening system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the anti-twist function with the central fastening element by integrating a projection directly onto the rotor shaft. This single integrated feature simultaneously provides both the form-fit connection for preventing twisting and serves as the central mounting point, eliminating the need for multiple separate screws and complex fastening systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the anti-twist function from a separate component (like a pin or multiple screws) and integrates it directly into the rotor shaft structure through the projection. This extraction and integration simplifies the overall fastening system while maintaining the necessary anti-twist security.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If a centrally arranged fastening element is used, then assembly is simplified and cost is reduced, but the rotor may still twist without an anti-twist device

Engineering Contradiction:
Improvefastening system simplicityVSAvoidanti-twist protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The projection is strategically positioned on the rotor shaft to provide localized form-fit engagement that specifically prevents twisting motion. This local geometric feature creates a mechanical interlock at the critical interface between rotor and shaft, providing anti-twist protection exactly where needed while maintaining the simplicity of the central fastening element.

Inventive Principle:
Principle #3Local quality

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 effectively prevents rotor twisting, ensuring a secure and cost-effective connection that maintains pump integrity and simplifies assembly by using a deformation-based anti-twist mechanism, which can be implemented with accessible centering pins or dowel pins, reducing the risk of imbalance and assembly complexity.

Implementation Method 1

at least one projection is arranged in a contact surface between the rotor and rotor shaft in the rotor or in the rotor shaft, which projection is a projection causing plastic deformation is formed in the opposing member

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2706237B1Vacuum pump
Publication Date: 2019.07.10 PFEIFFER VACUUM GMBH
  • EP2706237B1 patent drawingFigure 1
  • EP2706237B1 patent drawingFigure 2a~2b
  • EP2706237B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a vacuum pump with at least one gas inlet opening and at least one gas outlet opening, wherein the vacuum pump has at least one rotor shaft on which at least one rotor with rotating pump-active components, which are opposite stationary pump-active components, is attached with at least one fastening element arranged centrally in or on the rotor shaft in the axial direction, wherein the at least one rotor and the rotor shaft have an anti-rotation device in addition to the at least one fastening element.