Linear Compressor Suction Muffler Noise and Heat Trade-off

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Solution Overview

Problem

Existing linear compressors have limited noise reduction capabilities, particularly for various frequencies, and metal mufflers suffer from high heat transfer rates leading to significant heat losses and complex assembly processes.

Innovation Solution

A linear compressor design featuring a suction muffler with a plastic material construction, including a muffler main body and piston insertion parts with press-fitted coupling ribs and curved surfaces, which reduces noise through controlled refrigerant flow and minimizes heat transfer by using non-magnetic materials for the cylinder and piston, ensuring thermal compatibility and efficient assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a metal muffler is used, then noise reduction is achieved, but heat losses increase due to high heat transfer rate

Engineering Contradiction:
ImprovenoiseVSAvoidheat losses
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent changes the material parameter of the muffler from metal to plastic, which fundamentally alters the heat transfer characteristics. Plastic materials have lower thermal conductivity compared to metals, thereby reducing heat losses while maintaining noise reduction functionality through the muffler's structural design

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a metal muffler is used, then noise reduction is achieved, but manufacturing complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoidmolding difficulty
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from metal to plastic, which fundamentally improves manufacturability. Plastic materials can be easily molded into complex shapes using injection molding or similar processes, eliminating the difficulty of molding metal mufflers while maintaining noise reduction functionality

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If a plastic muffler is used, then heat losses are minimized, but noise reduction effectiveness decreases

Engineering Contradiction:
Improveheat lossesVSAvoidnoise
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent divides the muffler into multiple functional segments: a noise reduction chamber with sound-absorbing structures, a thermal insulation layer, and a refrigerant flow passage system. This segmentation allows the plastic muffler to simultaneously achieve heat loss minimization through insulation design and noise reduction through acoustic structures, despite using plastic material

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material construction for the muffler, combining plastic base material with thermal insulation layers and sound-absorbing materials. This composite approach enables the muffler to provide both thermal insulation properties to minimize heat losses and acoustic absorption properties to reduce noise, overcoming the limitations of single-material plastic construction

Inventive Principle:
Principle #40Composite materials

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 reduces noise across multiple frequency bands and minimizes heat losses while simplifying the assembly process by using plastic materials and non-magnetic components, enhancing the compressor's operational efficiency and reliability.

Implementation Method 1

the permanent magnet may be linearly reciprocated by a mutual electromagnetic force between the permanent magnet and the inner (or outer) stator

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a suction muffler positioned on a suction passage of the refrigerant inside the shell

Methodology Applied
Scientific EffectFluid flow control:

Data Source

PatentEP3093490B1Linear compressor
Publication Date: 2019.10.09 LG ELECTRONICS INC
  • EP3093490B1 patent drawingFigure 1
  • EP3093490B1 patent drawingFigure 2~3
  • EP3093490B1 patent drawingFigure 4

AI summary

A linear compressor comprising a cylinder (120) disposed in a shell (110); a piston (130) configured for linearly reciprocating inside the cylinder (120); a linear motor assembly (200) for exerting a driving force on the piston (130); a suction muffler (300) having a refrigerant passage for flowing a refrigerant therethrough, the suction muffler (300) being configured to be linearly movable with the piston (130), wherein the suction muffler (300) includes: a muffler main body (310) movably accommodated in a muffler guide (180); a main body insertion part (330) coupled to the inside of the muffler main body (310) and having a variable refrigerant passage section; and a piston insertion part (350) coupled to the muffler main body (310), being configured to extend into the piston (130).