Vacuum Pump Magnetic Coupling Gear Synchronization

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Solution Overview

Problem

Vacuum pumps with direct magnetic coupling face issues with synchronization loss when suctioning small solids, leading to potential rotor contact and damage, resulting in performance loss and increased gear size and complexity due to high load requirements.

Innovation Solution

The vacuum pump design incorporates gears that contact each other to resolve synchronization loss, utilizing a strong magnetic coupling between motor rotors to prevent rotor contact, reducing gear size and eliminating the need for lubrication, with gears placed inside either the motor or pump chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a stator core is used to form magnetic coupling between motor rotors, then the magnetic coupling is formed through the stator core, but the magnetic coupling force becomes weak due to the magnetic circuit formed inside the single shafts

Engineering Contradiction:
Improvemagnetic coupling forceVSAvoidmagnetic circuit structure
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The invention removes the stator core from the magnetic coupling structure. By eliminating the stator core, the magnetic circuit inside the single shafts is avoided, and a strong magnetic coupling force is achieved directly between the two motor rotors without the intermediate stator core structure.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If gears are increased in size to retain high strength for suppressing synchronization loss, then the gear strength is sufficient, but the vacuum pump size increases

Engineering Contradiction:
Improvegear strengthVSAvoidvacuum pump size
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

The invention positions the gears such that they come into contact with each other before the pump rotors when synchronization is lost. This preliminary contact allows the gears to correct synchronization errors before they can cause rotor contact, enabling the use of smaller, lighter gears that do not need to be oversized for strength.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If gears are provided in a space filled with lubricating oil to suppress wear, then gear wear is reduced, but the structure becomes complicated and the vacuum pump size increases

Engineering Contradiction:
Improvegear wear resistanceVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention uses self-lubricating materials for the gear surfaces, allowing the gears to lubricate themselves through their own material properties rather than requiring an external lubricating oil space. This eliminates the need for separate lubrication chambers and complex lubrication systems.

Inventive Principle:
Principle #25Self-service

4Force

If direct magnetic coupling is used between motor rotors without stator core, then the magnetic coupling force is enhanced, but synchronization may be lost when small solids are caught between pump rotors

Engineering Contradiction:
Improvemagnetic coupling forceVSAvoidsynchronization stability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The invention positions the gears to come into contact with each other before the pump rotors when synchronization is disturbed by foreign objects. This preliminary gear contact allows the gears to correct synchronization errors before they can cause rotor contact, maintaining reliable operation even with direct magnetic coupling.

Inventive Principle:
Principle #10Preliminary action

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 design ensures synchronized rotor operation without contact, reduces gear size and complexity, and eliminates the need for lubrication, enhancing efficiency and reliability by using self-lubricating materials or coatings.

Implementation Method 1

a magnetic coupling is directly formed by different magnetic pole faces of the motor rotors without a stator core interposed therebetween

Methodology Applied
Scientific EffectMagnetic coupling: Magnetism

Data Source

PatentEP3061973B1Vacuum pump
Publication Date: 2017.12.13 EBARA CORP
  • EP3061973B1 patent drawingFigure 1
  • EP3061973B1 patent drawingFigure 2~3
  • EP3061973B1 patent drawingFigure 4A~5A

AI summary

The present invention aims to realize a vacuum pump having a simple structure which can suppress contact between pump rotors even when synchronization between the pump rotors is lost. A vacuum pump 1000 includes: a pair of pump main shafts 310, 410 disposed facing each other; a pair of pump rotors 312, 412 provided on the pair of pump main shafts 310, 410; a pair of motor rotors 110, 210 provided on the pair of pump main shafts 310, 410 and directly forming a magnetic coupling by having different magnetic poles of magnets facing each other; and a pair of gears 380, 480 provided on the pair of pump main shafts 310, 410 and serving to synchronize the pair of pump rotors 312, 412.