Vacuum Pump Rotor Stator Spacer for Flooding Protection

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Solution Overview

Problem

Turbomolecular vacuum pumps face damage during severe flooding events due to improper pressure equalization, which can cause stator and rotor blades to collide, leading to damage and malfunction.

Innovation Solution

A spacer element is introduced between the rotor and stator blades, designed as a ring around the rotor's axis of rotation, to maintain a safe distance and prevent direct contact during flooding, thereby minimizing damage and ensuring smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the flooding process is allowed to proceed without restriction, then pressure equalization occurs, but the stator and rotor blades may collide causing damage

Engineering Contradiction:
Improvedamage preventionVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A spacer element is introduced as an intermediary component between the rotor and stator. This spacer acts as a mediator that prevents direct contact between the rotor blades and stator blades during flooding events, thereby protecting both components from collision damage while maintaining the overall simplicity of the pump structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spacer element is pre-installed on the rotor in advance, creating a protective barrier before flooding occurs. This preliminary protective measure ensures that when pressure equalization happens during flooding, the stator blades cannot come into contact with the rotor blades, preventing damage before it can occur.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If the stator is made of sheet metal for ease of manufacture, then manufacturing cost decreases, but the stator may bend during flooding and hit the rotor

Engineering Contradiction:
Improvestator manufacturingVSAvoidcollision prevention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The spacer element serves as a protective intermediary that compensates for the flexibility of sheet metal stators. Even though the sheet metal stator may bend during flooding due to pressure changes, the spacer prevents this bending from resulting in contact between the stator blades and rotor blades, thus maintaining reliability while preserving manufacturing simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the rotor blades are positioned close to the stator for efficient pumping, then pumping performance improves, but the risk of contact during flooding increases

Engineering Contradiction:
Improvepumping efficiencyVSAvoidcontact risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The spacer element acts as a protective intermediary that allows the rotor blades to be positioned close to the stator for efficient pumping during normal operation. During flooding events, the spacer prevents harmful contact between the rotor and stator blades, thus eliminating the trade-off between pumping efficiency and contact risk.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The spacer element provides beforehand cushioning by creating a physical barrier that absorbs or prevents the harmful effect of pressure equalization during flooding. This protective cushion allows the rotor-stator gap to be minimized for efficiency while the spacer absorbs the shock of flooding events.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP3096020B1Vacuum pump
Publication Date: 2019.12.11 PFEIFFER VACUUM GMBH
  • EP3096020B1 patent drawingFigure 1
  • EP3096020B1 patent drawingFigure 2I~2III
  • EP3096020B1 patent drawingFigure 3A~3F

AI summary

The invention relates to a vacuum pump, in particular a turbomolecular pump, with a rotor rotatably mounted in the vacuum pump and comprising a portion on which several rotor blades are arranged, and a stator axially offset from the portion of the rotor having the rotor blades in a housing of the vacuum pump and comprising at least one stator blade. A spacer element is arranged between the portion having the rotor blades and the stator, the spacer element being designed to keep the at least one stator blade at a distance from the rotor when the stator bends.