Scroll Compressor Pressure Line for Adaptive Counter-Pressure Control

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Solution Overview

Problem

Existing scroll compressors for vehicle air conditioning systems face challenges in maintaining optimal pressure in the counter-pressure chamber across different operating points, leading to potential leaks and increased friction losses between the fixed and orbiting scrolls.

Innovation Solution

A two-channel pressure line system is implemented in the fixed scroll, where the first channel connects to the compression chamber and the second channel connects to the high-pressure chamber, creating a static pressure that communicates with the counter-pressure chamber, allowing for adaptive pressure adjustment without additional flow-regulating components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single medium-pressure channel is used to connect the compressor chamber to the backpressure chamber, then the structure is simple, but the pressure adjustment capability across different operating points is insufficient

Engineering Contradiction:
Improvepressure adjustment capabilityVSAvoidpressure line structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single medium-pressure channel is divided into two separate channels: a first medium-pressure channel and a second medium-pressure channel. Each channel can be independently controlled to open or close based on operating conditions. This segmentation allows the system to adapt to different operating points (cooling mode vs. heat pump mode) by selectively opening the appropriate channel, thereby improving pressure adjustment capability without significantly increasing structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pressure line structure is made dynamic by enabling the two medium-pressure channels to be selectively opened or closed depending on the operating mode. In cooling mode, the first channel opens while the second remains closed; in heat pump mode, the second channel opens while the first remains closed. This dynamic configuration allows optimal pressure adjustment for each operating condition, resolving the contradiction between adaptability and structural simplicity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the orbiting scroll is pressed against the stationary scroll to prevent leaks, then sealing is improved, but friction losses between the scrolls increase

Engineering Contradiction:
Improvesealing performanceVSAvoidfriction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The axial force between the orbiting and stationary scrolls is optimized by adjusting the pressure parameters in the backpressure chamber. The two medium-pressure channels enable different pressure levels to be applied in different operating modes, which adjusts the contact pressure between the scrolls. This ensures sufficient sealing performance while minimizing friction losses by using the minimum necessary contact pressure for each operating condition.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses the compression process itself to generate the backpressure that presses the orbiting scroll against the stationary scroll. The medium-pressure channels automatically route the compressed refrigerant to the backpressure chamber, creating a self-regulating mechanism where the sealing force is generated by the compression process itself rather than requiring external actuation, thereby reducing energy losses.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If additional flow-regulating components are added to the pressure line, then pressure control precision is improved, but device complexity increases

Engineering Contradiction:
Improvepressure control precisionVSAvoidflow-regulating components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the need for additional flow-regulating components by using the inherent pressure differential created during the compression process. The two medium-pressure channels are designed to open or close based on the operating mode, and the pressure control is achieved through the natural pressure differences in the compression chambers rather than requiring separate flow-regulating devices. This maintains pressure control precision while avoiding the complexity of additional components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The backpressure chamber acts as an intermediary that receives compressed refrigerant through the two medium-pressure channels and uses this pressure to regulate the contact between the scrolls. This intermediary mechanism provides precise pressure control without requiring direct flow regulation in the main compression path, thereby achieving accurate pressure control while maintaining system simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enables effective self-adjustment of pressure in the counter-pressure chamber, reducing leaks and friction losses, and maintaining high efficiency across cooling and heat pump modes by ensuring the axial force is minimal, thus improving the operational stability and performance of the scroll compressor.

Implementation Method 1

a pressure line (35), which runs at least partially within the stationary scroll (23), and a first channel (36) connected to at least one of the compressor chambers (24), and a second channel (37) connected to the high-pressure chamber (29). As a result of operational processes, a static pressure is generated or prevails in the pressure line (35), through which the counter-pressure chamber (25) communicates fluidically with the high-pressure chamber (29) and with at least one compressor chamber (24)

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

This valve opens due to the pressure differential between the compressor chambers and the high-pressure chamber. If necessary, the compressed gas-oil mixture flows into the high-pressure chamber of the scroll compressor (on the rear of the stationary scroll) after the valve is triggered

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

During operation of the scroll compressor, the pressure generated in the compressor chambers and the resulting axial force push the two scrolls apart, potentially creating a gap and thus leaks between the chambers. To prevent this as much as possible, the orbiting scroll is pressed against the stationary scroll

Methodology Applied
Scientific EffectAxial force: Mechanical Force

Data Source

PatentEP3667086B1Spiral-type displacement machine, in particular a displacement machine for a vehicle air-conditioning system
Publication Date: 2023.03.29 BROSE FAHRZEUGTEILE GMBH & CO KG
  • EP3667086B1 patent drawingFigure 1
  • EP3667086B1 patent drawingFigure 2
  • EP3667086B1 patent drawingFigure 3

AI summary

The disclosure relates to a scroll compressor (3) for refrigerant of a vehicle air conditioning system, comprising a housing (12) with a high-pressure chamber (29) and with compressor chambers (24) as well as with a back-pressure chamber (25), a stationary scroll (23) whose base plate (23b) delimits the high-pressure chamber (29), and a movable scroll (21) whose spiral wall (21a) engages in the spiral wall (23b) of the stationary scroll (23) and forms the compressor chambers (24) with it, wherein the base plate (21b) of the movable scroll (21) delimits the back-pressure chamber (25), and wherein a pressure line (35) connected to the compressor chambers (24) and to the high-pressure chamber (29) runs at least partially in the stationary scroll (23) and is connected via a first channel (36) to at least one of the compressor chambers (24) and via a second channel (37) to the high-pressure chamber (29).