Scroll Compressor Back Pressure Chamber Integration

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Solution Overview

Problem

Existing scroll compressors face issues with refrigerant backflow and over-compression due to the lack of a discharge valve in the non-orbiting back pressure method, leading to reduced efficiency and reliability, and the separate manufacturing of back pressure chamber assemblies increases manufacturing costs.

Innovation Solution

The integration of a back pressure chamber with a floating plate and discharge valve on the non-orbiting scroll, where the outer and inner wall portions form the back pressure chamber, reducing the number of components and assembly steps, and the use of a floating plate with adjustable positions to enhance sealing and prevent backflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a back pressure chamber assembly is separately manufactured and assembled onto the non-orbiting scroll, then the back pressure function is achieved, but the number of components and assembly processes increases, resulting in increased manufacturing costs

Engineering Contradiction:
Improveback pressure functionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The back pressure chamber is integrated directly into the non-orbiting scroll body as a unified structure, eliminating the need for separate back pressure chamber assemblies. The non-orbiting scroll includes a back pressure chamber formation that creates the back pressure chamber internally, thereby reducing component count and simplifying manufacturing while maintaining the back pressure function.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If the back pressure chamber assembly is separately manufactured, then assembly flexibility is improved, but the number of assembly steps and manufacturing complexity increases

Engineering Contradiction:
Improveassembly flexibilityVSAvoidnumber of components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The back pressure chamber is merged with the non-orbiting scroll to form a single integrated component. The non-orbiting scroll includes integrally formed outer and inner wall portions that define the back pressure chamber, eliminating separate assembly steps and reducing overall device complexity while maintaining functional adaptability.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a discharge valve is not installed, then the structure is simpler, but refrigerant backflow occurs when the compressor is stopped, inhibiting restart

Engineering Contradiction:
Improvestructure simplicityVSAvoidrestart capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The discharge valve is designed to automatically open and close based on pressure differential. When the compressor stops and discharge chamber pressure exceeds compression chamber pressure, the valve automatically closes to prevent backflow. When the compressor restarts and compression chamber pressure exceeds discharge chamber pressure, the valve automatically opens, eliminating the need for external control mechanisms.

Inventive Principle:
Principle #25Self-service

4Device complexity

If a bypass valve is not installed, then the structure is simpler, but over-compression occurs, reducing efficiency and reliability

Engineering Contradiction:
Improvestructure simplicityVSAvoidover-compression prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The bypass valve is designed to automatically activate when compression chamber pressure exceeds a predetermined threshold. The valve body includes a movable valve element that responds to pressure differential, automatically opening to bypass refrigerant when over-compression is detected and closing when pressure normalizes, providing self-regulating over-compression protection without complex control systems.

Inventive Principle:
Principle #25Self-service

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 configuration effectively prevents refrigerant backflow, reduces manufacturing costs, and improves compressor efficiency by integrating the back pressure chamber and discharge valve directly onto the non-orbiting scroll, ensuring reliable operation and simplified assembly.

Implementation Method 1

a floating plate (165) that moves up and down by a pressure of the back pressure chamber to adjust the pressure in the back pressure chamber

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

a discharge valve (157) that opens and closes a discharge port (1511)

Methodology Applied
Scientific EffectValve mechanism: Valve

Implementation Method 3

a bypass valve (158) that opens and closes a bypass hole (1512)

Methodology Applied
Scientific EffectValve mechanism: Valve

Implementation Method 4

as the orbiting scroll performs an orbiting motion with respect to the non-orbiting scroll

Methodology Applied
Scientific EffectOrbiting motion: Eccentric

Implementation Method 5

the non-orbiting scroll and the orbiting scroll should be tightly sealed in an axial direction to suppress leakage between the pair of compression chambers

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP3995697B1Scroll compressor
Publication Date: 2024.10.23 LG ELECTRONICS INC
  • EP3995697B1 patent drawingFigure 1
  • EP3995697B1 patent drawingFigure 2
  • EP3995697B1 patent drawingFigure 3

AI summary

A scroll compressor is provided that may include a casing, a drive motor, an orbiting scroll, a non-orbiting scroll, and a floating plate provided with a cover portion to cover an area between an outer wall portion and an inner wall portion of the non-orbiting scroll so as to form a back pressure chamber with the non-orbiting scroll, and a valve accommodating portion that extends from the cover portion so as to accommodate a discharge valve configured to open and close a discharge port. Accordingly, structure for forming a back pressure chamber is simplified to thereby reduce the number of components and manhours required for assembly.