Scroll Compressor Bypass Hole Layout for Overcompression Control

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Solution Overview

Problem

Existing scroll compressors face issues with increased manufacturing costs, assembly complexity, and efficiency degradation due to the need for additional components like back pressure chambers and bypass valves, which can lead to overcompression and refrigerant leakage.

Innovation Solution

A scroll compressor design that integrates a bypass hole and bypass valve within the non-orbiting scroll, minimizing the length of the bypass hole and reducing assembly complexity by configuring the back pressure chamber as a single body, while using a floating plate to enhance sealing and a bypass valve that responds quickly to pressure differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a back pressure chamber assembly is separately manufactured and fastened to the rear surface of the non-orbiting scroll, then the sealing performance is improved, but the number of parts increases and assembly complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The back pressure chamber is integrated directly into the non-orbiting scroll as a unified structure, eliminating the need for separate back pressure chamber assemblies. This merging of components reduces the total number of parts while maintaining the sealing function through the integrated design that forms the back pressure chamber within the scroll's own structure.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a bypass hole and bypass valve are installed through the back pressure chamber inner wall, then overcompression is prevented, but the length of the bypass hole increases and dead volume increases

Engineering Contradiction:
Improveovercompression preventionVSAvoiddead volume
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

Instead of drilling a long bypass hole through the entire back pressure chamber inner wall from the rear surface, the bypass hole is configured to start from the discharge port area and extend in a different spatial dimension toward the back pressure chamber. This dimensional reconfiguration shortens the bypass hole length and reduces the associated dead volume while still providing effective overcompression protection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the bypass hole length is increased to ensure proper valve installation, then the bypass valve can be properly installed, but the dead volume increases and efficiency decreases

Engineering Contradiction:
Improvebypass valve installationVSAvoidcompressor efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The bypass hole is configured to extend from the discharge port area in a optimized spatial direction that allows proper bypass valve installation without requiring excessive length. By changing the dimensional orientation of the bypass hole, the design achieves adequate valve mounting space while minimizing the hole length and associated dead volume, thus maintaining compressor efficiency.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 reduces manufacturing costs, minimizes dead volume, and enhances operational efficiency by preventing overcompression and refrigerant leakage, thereby improving the compressor's reliability and performance.

Implementation Method 1

a bypass valve for opening and closing the bypass hole according to a pressure difference between the compression chamber and the discharge chamber

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

a floating plate that moves up and down according to a pressure in the back pressure chamber

Methodology Applied
Scientific EffectPressure: Pressure Gradient

Data Source

PatentEP4198314B1Scroll compressor
Publication Date: 2025.09.03 LG ELECTRONICS INC
  • EP4198314B1 patent drawingFigure 1
  • EP4198314B1 patent drawingFigure 2
  • EP4198314B1 patent drawingFigure 3

AI summary

In a scroll compressor, a discharge chamber is provided in an inner space of a back pressure chamber inner wall, a discharge port is provided inside the discharge chamber, a bypass hole is provided around the discharge port, and a communicating recess portion allowing the discharge chamber to communicate with the bypass hole is provided on an inner circumferential surface of the back pressure chamber inner wall forming the discharge chamber. Through this, the bypass hole may be easily configured in addition to the discharge port, thereby increasing an operation range of the compressor and suppressing overcompression.