Compressor Integrated Muffler Structure to Reduce Refrigerant Noise

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Solution Overview

Problem

The distance between the discharge port of a compressor's compression mechanism and an external muffling device leads to noise generation in the refrigerant flow, compromising low-noise properties.

Innovation Solution

A compressor design with an integrated muffler structure comprising a first and second muffler portion connected in series, forming expansion and contraction spaces, and an oil separator to attenuate refrigerant noise upstream, reducing the need for separate muffling devices and minimizing noise generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a muffling device is attached outside the compressor, then the compressor structure remains simple, but the distance from the discharge port to the muffling device causes refrigerant noise

Engineering Contradiction:
Improvecompressor structureVSAvoidrefrigerant noise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent combines the muffling function with the existing discharge chamber structure by adding a partition wall with a small passage. This integration eliminates the need for a separate external muffling device, maintaining structural simplicity while reducing the distance between the discharge port and muffling element, thereby suppressing refrigerant noise effectively.

Inventive Principle:
Principle #5Merging (Combining)

2Loss of energy

If the passage cross-sectional area in the muffler is increased, then refrigerant flow resistance decreases, but the noise attenuation effect is reduced

Engineering Contradiction:
Improverefrigerant flow resistanceVSAvoidnoise attenuation
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent creates a localized narrow passage within the partition wall of the discharge chamber. This local restriction is strategically positioned to generate pressure fluctuations that attenuate noise, while the overall discharge path remains sufficiently large to maintain acceptable flow characteristics. The small passage area is confined to a specific location rather than the entire flow path.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent optimizes the passage parameters (cross-sectional area and length) to achieve the desired balance between noise attenuation and flow resistance. By carefully selecting these dimensional parameters, the system achieves effective noise suppression while minimizing energy loss in the refrigerant flow.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If the passage length in the muffler is increased, then noise attenuation effect improves, but the compressor size increases

Engineering Contradiction:
Improvenoise attenuationVSAvoidcompressor size
Core Design Contradiction:
Object-generated harmful factorsVSVolume of moving object

Solution Approach 1:

The patent integrates the muffling passage within the existing discharge chamber volume by using a partition wall structure. This approach allows the passage length to be extended for better noise attenuation without significantly increasing the overall compressor external dimensions, as the passage utilizes the available internal space of the discharge chamber.

Inventive Principle:
Principle #5Merging (Combining)

4Object-generated harmful factors

If a separate muffling device is added, then noise reduction is achieved, but manufacturing costs increase

Engineering Contradiction:
Improvenoise reductionVSAvoidmanufacturing cost
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The patent integrates the muffling function into the existing compressor discharge chamber structure by adding a partition wall with a small passage. This eliminates the need for a separate external muffling device, reducing the number of parts, assembly steps, and manufacturing costs while achieving effective noise reduction.

Inventive Principle:
Principle #5Merging (Combining)

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 integrated muffler structure effectively attenuates refrigerant noise by repeating expansion and contraction, improving noise reduction efficiency and reducing costs by eliminating the need for external muffling devices.

Implementation Method 1

the first muffler portion (S1) and the second muffler portion (S2) are connected in series such that a refrigerant gas repeats expansion and contraction

Methodology Applied
Scientific EffectExpansion and contraction:

Implementation Method 2

the pressure pulsations of the refrigerant gas discharged through the compression-chamber outlet (26) can be attenuated on a relatively upstream side

Methodology Applied
Scientific EffectPressure pulsation attenuation: Damping

Implementation Method 3

a separation space (51) for separating oil from the refrigerant is formed

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentEP4296512B1compressor
Publication Date: 2026.03.04 DAIKIN INDUSTRIES LTD
  • EP4296512B1 patent drawingFigure 1
  • EP4296512B1 patent drawingFigure 2
  • EP4296512B1 patent drawingFigure 3

AI summary

A compressor (10) includes a compression mechanism (20) and a muffler structure (M) that is disposed at a discharge flow path (38) through which a compression-chamber outlet (26) of the compression mechanism (20) and the inflow end of the discharge pipe (8) are in communication with each other. The muffler structure (M) includes a first muffler portion (S1) and a second muffler portion (S2) that are connected in series such that a refrigerant gas repeats expansion and contraction.