Scroll Compressor Axial Biasing Chamber Pressure Modulation

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Solution Overview

Problem

Existing compressors in climate-control systems face inefficiencies in capacity modulation, leading to suboptimal performance and increased wear due to uneven pressure distribution between scrolls, which affects operational efficiency and reliability.

Innovation Solution

The compressor incorporates a capacity modulation assembly with a first and second scroll, axial biasing chamber, and valves that allow for fluid communication between intermediate-pressure compression pockets and the axial biasing chamber, enabling switching between full-capacity and reduced-capacity modes by controlling the pressure differential, thereby optimizing scroll alignment and reducing friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If capacity modulation is implemented in existing compressors, then operational efficiency is improved, but uneven pressure distribution between scrolls increases causing increased wear and suboptimal performance

Engineering Contradiction:
Improveoperational efficiencyVSAvoidscroll wear and performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

An axial biasing chamber is introduced as an intermediary component between the compression chambers and the discharge end plate. This chamber receives working fluid from intermediate-pressure compression pockets through selective ports and applies axial biasing force to the discharge end plate, thereby evenly distributing pressure between the first and second scrolls during capacity modulation. This mediator component resolves the pressure distribution imbalance that previously caused increased wear and suboptimal performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the pressure parameter in the axial biasing chamber by selectively communicating with different intermediate-pressure compression pockets (first, second, or third pockets at different radial positions) through movable ports. By adjusting which compression pocket communicates with the biasing chamber, the system modifies the pressure applied to the discharge end plate, thereby optimizing scroll alignment and reducing friction under varying operating conditions including capacity modulation.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If working fluid pressure is increased in the axial biasing chamber, then scroll alignment is optimized reducing friction, but excessive pressure may cause increased stress on components

Engineering Contradiction:
Improvescroll alignment and frictionVSAvoidcomponent stress
Core Design Contradiction:
Ease of operationVSStress or pressure

Solution Approach 1:

The system dynamically adjusts the pressure in the axial biasing chamber by selectively communicating with different intermediate-pressure compression pockets based on operating conditions. The movable ports can switch between connecting to the first, second, or third compression pockets at different radial positions, thereby dynamically optimizing scroll alignment while preventing excessive pressure buildup. This dynamic adaptation ensures friction reduction without imposing excessive stress on components.

Inventive Principle:
Principle #15Dynamics

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 enhances operational efficiency, minimizes wear, and improves power consumption by ensuring appropriate pressure distribution across the scrolls, leading to better performance and reliability in both full-capacity and reduced-capacity modes.

Implementation Method 1

Working fluid disposed within the axial biasing chamber axially biases the second scroll toward the first scroll

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

The first and second spiral wraps mesh with each other and form a plurality of compression pockets therebetween. The compression pockets include a suction-pressure compression pocket, a discharge-pressure compression pocket at a higher pressure than the suction-pressure pocket

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3810934B1Scroll compressor having an axial biasing chamber
Publication Date: 2024.08.28 COPELAND LP
  • EP3810934B1 patent drawingFigure 1~2
  • EP3810934B1 patent drawingFigure 3~4
  • EP3810934B1 patent drawingFigure 5~6

AI summary

A compressor may include first and second scrolls, and an axial biasing chamber. Spiral wraps of the scrolls mesh with each other and form compression pockets including a suction-pressure compression pocket, a discharge-pressure compression pocket, and intermediate-pressure compression pockets. The axial biasing chamber may be disposed axially between the second end plate and a component. Working fluid disposed within the axial biasing chamber may axially bias the second scroll toward the first scroll. The second end plate includes outer and inner ports. The outer port is disposed radially outward relative to the inner port. The outer port may be open to a first one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber. The inner port may be open to a second one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber.