Magnetic Rotor Fluoropolymer Sheath Parylene Coating

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Solution Overview

Problem

Existing rotary machines with magnetically mounted rotors, particularly in the semiconductor industry, face challenges in protecting permanent magnets from acidic and chemically aggressive substances, as current protective measures like fluorinated hydrocarbon coatings are insufficient against gaseous components and metallic sheaths are difficult to weld without damaging the magnetic material.

Innovation Solution

A magnetically storable rotor design featuring a thermoplastically processable fluoropolymer sheath that completely encloses a permanent magnet with a metallic coating, where a parylene polymer coating is interposed between the metallic coating and the sheath, providing enhanced protection against both liquid and gaseous aggressive substances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fluorinated hydrocarbon coating is applied to protect permanent magnets, then resistance to liquid acids is improved, but protection against gaseous components is insufficient

Engineering Contradiction:
Improveprotection against liquid acidsVSAvoidpenetration by gaseous components
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a composite protective system consisting of multiple layers: a fluorinated hydrocarbon coating (providing chemical inertness and resistance to liquid acids), a metallic coating (providing barrier protection against gaseous components), and a plastic coating (providing additional protection and adhesion). This multi-layer composite structure combines the advantages of each material to achieve comprehensive protection against both liquid and gaseous aggressive substances.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The protective layers are arranged in a nested configuration where the metallic coating is applied directly to the permanent magnet, the plastic coating is applied over the metallic coating, and the fluorinated hydrocarbon coating is applied over the plastic coating. This nested structure ensures that each layer protects the underlying layers, creating a hierarchical defense system against corrosive substances.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Object-affected harmful factors

If a metallic sheath is applied to protect against gaseous components, then protection against gas penetration is improved, but welding difficulty and risk of damaging magnetic material increase

Engineering Contradiction:
Improveprotection against gaseous componentsVSAvoidwelding difficulty
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The metallic coating is applied to the permanent magnet before the plastic and fluorinated hydrocarbon coatings. This preliminary application of the metallic layer provides immediate protection against gaseous components, while subsequent layers are applied to protect the metallic coating during handling and assembly operations, reducing the risk of damage during welding and assembly processes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The plastic and fluorinated hydrocarbon coatings serve as protective cushions over the metallic coating. These outer layers protect the metallic layer from mechanical damage, oxidation, and other environmental factors before the actual welding or assembly operations take place, thereby reducing the risk of damaging the magnetic material during manufacturing.

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

3Power

If permanent magnets are exposed to acidic and chemically aggressive substances, then magnetic functionality is maintained, but corrosion and metal ion contamination occur

Engineering Contradiction:
Improvemagnetic functionalityVSAvoidmetal ion contamination
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The multi-layer composite protective system (metallic coating, plastic coating, and fluorinated hydrocarbon coating) creates a comprehensive barrier that prevents acidic and chemically aggressive substances from contacting the permanent magnet. This composite structure maintains the magnetic functionality of the permanent magnet while preventing corrosion and metal ion contamination by blocking the diffusion path of aggressive substances.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The metallic, plastic, and fluorinated hydrocarbon coatings act as intermediary layers between the permanent magnet and the aggressive external environment. These intermediary layers prevent direct contact between the magnetic material and corrosive substances, thereby protecting the magnet from degradation while allowing the magnetic field to function normally.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 diffusion of aggressive substances to the magnetically active core, offering long-lasting protection against acidic fluids and gases, preventing corrosion and metal ion contamination, thus ensuring the integrity of semiconductor processes.

Implementation Method 1

a plastic coating is provided between the metallic coating and the sheathing, which consists of a polymer belonging to the family of the parylenes

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Implementation Method 2

the rotor is stored without contact by means of separate magnetic bearings

Methodology Applied
Scientific EffectMagnetic levitation: Maglev

Implementation Method 3

the drive unit comprises a drive stator with which the rotor is transferred in rotation according to the principle of an electromagnetic rotary drive

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3425204B1Magnetic rotor and machine with such a rotor
Publication Date: 2021.04.14 LEVITRONIX GMBH(CH)
  • EP3425204B1 patent drawingFigure 1
  • EP3425204B1 patent drawingFigure 2
  • EP3425204B1 patent drawingFigure 3

AI summary

A magnetically buoyant rotor is proposed for a rotary machine with a magnetically buoyant rotor. The rotor comprises a magnetically effective core (2) and a casing (3) made of a thermoplastic fluoropolymer. The casing (3) completely encloses the magnetically effective core (2), which includes at least one permanent magnet (21). Each permanent magnet (21) has a metallic coating (6) for protection against acidic or chemically aggressive substances. A plastic coating (7) made of a polymer belonging to the parylene family is provided between the metallic coating (6) and the casing (3). A rotary machine (100) with such a rotor is also proposed.