Scroll Compressor Back-Pressure Chamber Tilt Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In scroll compressors, once the orbiting scroll tilts due to differential pressure fluctuations, it is difficult to quickly restore normal operation as fluid leaks through widened gaps, leading to excessive time for pressure equalization and increased separation forces.

Innovation Solution

The implementation of an auxiliary introduction mechanism that supplies fluid to the back-pressure chamber before the introduction mechanism, using a check valve to maintain pressure and reduce tilt, along with overlapping supply periods to ensure continuous high-pressure fluid delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the orbiting scroll tilts due to differential pressure fluctuations, then the gap of the thrust surface widens, but fluid leaks from the back-pressure chamber into the suction side, making it difficult to restore normal operation

Engineering Contradiction:
Improvestability of orbiting scroll positionVSAvoidtime to restore normal operation
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces a back-pressure chamber that is pre-configured to receive fluid from the compression chamber. When the orbiting scroll tilts, this pre-established pressure chamber provides immediate counter-pressure to restore the scroll to its correct position, preventing the widening of thrust surface gaps and fluid leakage. The back-pressure chamber acts as a preliminary protective mechanism against tilt-induced failures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The back-pressure chamber serves as an intermediary element between the compression chamber and the suction side. It mediates the pressure fluctuations by providing a controlled intermediate pressure zone that prevents direct communication between high-pressure and low-pressure regions when the orbiting scroll tilts, thereby stopping fluid leakage through widened gaps.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the orbiting scroll tilts, then a gap is created between end faces of wraps and end plates, but high-pressure fluid leaks toward the suction port, causing excessive compression and pressure rise

Engineering Contradiction:
Improvesealing integrity of compression chamberVSAvoidinternal pressure of compression chamber
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The back-pressure chamber acts as an intermediary pressure zone that prevents direct leakage paths between the compression chamber and suction port. When the orbiting scroll tilts and creates gaps, the controlled pressure in the back-pressure chamber interrupts the high-pressure fluid flow, preventing excessive pressure build-up in the compression chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potential harmful effect of pressure fluctuations into a beneficial control mechanism. By intentionally creating a back-pressure chamber with controlled pressure, the system uses pressure differential as a corrective force to maintain sealing integrity and prevent harmful leakage when tilts occur.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If fluid is supplied to the back-pressure chamber to reduce orbiting scroll tilt, then pressing force is applied opposite to thrust direction, but excessive time is required to raise back-pressure chamber pressure

Engineering Contradiction:
Improveorbiting scroll alignmentVSAvoidtime to raise back-pressure chamber pressure
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The back-pressure chamber is pre-configured with fluid supply passages and pressure control mechanisms before any tilt occurs. This preliminary preparation allows the chamber to immediately begin counteracting tilt forces without requiring time-consuming pressure build-up, as the infrastructure is already in place to rapidly respond to alignment disturbances.

Inventive Principle:
Principle #10Preliminary action

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 allows for quick pressure recovery in the back-pressure chamber, reducing the tilt of the orbiting scroll and facilitating a rapid return to normal operation by providing sustained pressing force and minimizing separation forces.

Implementation Method 1

the check valve (82) blocks the fluid of the back-pressure chamber (56) from back-flowing through an auxiliary introduction passage (81) to the compression chamber (31)

Methodology Applied
Scientific EffectCheck valve one-way flow control: Valve

Implementation Method 2

the supply of the refrigerant creates pressing force to be applied to the orbiting scroll in a direction opposite to a thrust direction of the load of gas in the compression chamber, thereby reducing the tilt of the orbiting scroll

Methodology Applied
Scientific EffectPressure differential force: Pressure Gradient

Data Source

PatentEP3073117B1Scroll compressor
Publication Date: 2021.01.20 DAIKIN INDUSTRIES LTD
  • EP3073117B1 patent drawingFigure 1
  • EP3073117B1 patent drawingFigure 2
  • EP3073117B1 patent drawingFigure 3

AI summary

A scroll compressor comprises a compression mechanism (30) including (i) an introduction mechanism (70) supplying, throughout a first period, a fluid of the compression chamber (31) to a back-pressure chamber (56) in back of the orbiting scroll (35), and (ii) an auxiliary introduction mechanism (80) supplying, throughout a second period, the fluid of the compression chamber (31) to the back-pressure chamber (56), and the second period including a time point prior to the first period.