Magnetic Drive Coupling for Hermetic Compressor Sealing

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Solution Overview

Problem

Conventional compressor drive configurations with mechanical face seals suffer from oil and refrigerant leakage, leading to field complaints and costly rework due to the inability to maintain a hermetic seal effectively.

Innovation Solution

A magnetic drive coupling apparatus replaces the mechanical face seal with a sealed magnetic drive coupling, utilizing a hermetically sealed pressure barrier and magnetically attractive parts to transmit torque between the drive and driven units, preventing fluid leakage by using a sealing unit that encompasses the magnetically attractive parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a mechanical face seal is used to couple the compressor to the motor, then the compressor can be mechanically coupled to the drive source, but oil and refrigerant leak through the seal

Engineering Contradiction:
Improvemechanical couplingVSAvoidfluid leakage
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical face seal coupling with a magnetic drive coupling system. The magnetic coupling uses magnetic fields to transmit rotational force from the motor to the compressor without physical contact between the drive and driven sides, eliminating the leakage path that exists in mechanical seal systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the motor and compressor. The magnetic coupling creates a magnetic barrier that allows torque transmission while maintaining hermetic separation, with the magnetic field acting as the mediator that transfers energy without allowing fluid passage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a hermetic seal is implemented to prevent fluid leakage, then fluid sealing is improved, but the drive configuration becomes more complex

Engineering Contradiction:
Improvehermetic sealingVSAvoiddrive configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the drive coupling function and hermetic sealing function into a single integrated magnetic drive coupling assembly. The magnetic coupling structure inherently provides both torque transmission and hermetic separation, merging what would traditionally be separate functions into one unified system.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a mechanical face seal is used, then the structure is simpler, but oil leakage occurs requiring rework

Engineering Contradiction:
Improveseal structureVSAvoidleak prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent replaces the simple mechanical face seal with a magnetic drive coupling system that uses magnetic fields instead of mechanical contact. This substitution eliminates the fundamental leakage mechanism of mechanical seals while maintaining relatively simple overall system architecture.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 magnetic drive coupling apparatus eliminates oil and refrigerant leaks, reducing repair costs and ensuring a hermetically sealed environment, thereby enhancing the reliability and efficiency of compressor operations.

Implementation Method 1

a magnetic drive coupling having first and second magnetically attractive parts associated with the first and second rotatable shafts, respectively, which transmits rotation between the first and second rotatable shafts

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP2710719B2Magnetic drive coupling apparatus
Publication Date: 2020.04.29 CARRIER CORP
  • EP2710719B2 patent drawingFigure 1
  • EP2710719B2 patent drawingFigure 2

AI summary

A magnetic drive coupling apparatus is provided and includes a drive unit having a first rotatable shaft and an open drive assembly, a driven unit having an end face and a second rotatable shaft extending through the end face axially overlap, a magnetic drive coupling having first and second magnetically attractive parts associated with the first and second rotatable shafts, respectively, which transmits rotation between the first and second rotatable shafts and a sealing unit coupled to the end face to encompass the second magnetically attractive part and to hermetically seal oil and refrigerant in an interior of the driven unit.