Moving Scroll Collection Groove for Compressor Thrust Balance

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Solution Overview

Problem

The moving scroll of a compressor experiences inefficiencies due to thrust imbalances between the compression and backpressure chambers, leading to fluid leakage or excessive friction, which affects its working efficiency.

Innovation Solution

The moving scroll design incorporates a collection groove extending between 60 to 400 degrees around the axis, with a fluid inlet at the collection end, allowing for balanced pressure compensation between the compression and backpressure chambers, minimizing leakage and friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the compression thrust is greater than the backpressure thrust, then the compression force is sufficient, but the moving scroll breaks contact with the static scroll causing fluid leakage

Engineering Contradiction:
Improvecompression thrustVSAvoidcontact stability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by introducing a backpressure chamber that generates backpressure thrust in advance to counterbalance the compression thrust. The backpressure chamber is positioned to receive high-pressure refrigerant, creating a counteracting force that prevents the moving scroll from breaking contact with the static scroll, thus maintaining reliable contact stability while preserving sufficient compression force.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If the compression thrust is less than the backpressure thrust, then contact is maintained, but excessive friction occurs reducing efficiency

Engineering Contradiction:
Improvecontact stabilityVSAvoidfriction loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the backpressure through the backpressure chamber. The backpressure chamber receives high-pressure refrigerant whose pressure can vary, allowing the backpressure thrust to be adjusted to match the compression thrust. This dynamic parameter adjustment maintains optimal contact stability while minimizing friction loss and improving overall efficiency.

Inventive Principle:
Principle #35Parameter changes

3Stress or pressure

If thrust imbalance occurs between compression and backpressure chambers, then pressure equilibrium is disrupted, but working efficiency decreases

Engineering Contradiction:
Improvepressure equilibriumVSAvoidworking efficiency
Core Design Contradiction:
Stress or pressureVSProductivity

Solution Approach 1:

The patent applies feedback by using the backpressure chamber to sense and respond to compression thrust variations. The backpressure chamber receives high-pressure refrigerant from the compression chamber, and the resulting backpressure thrust automatically adjusts to counterbalance the compression thrust. This feedback mechanism maintains pressure equilibrium and optimizes working efficiency by dynamically balancing the thrust forces.

Inventive Principle:
Principle #23Feedback

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

The solution achieves improved compression efficiency by maintaining equilibrium between the pressures in the compression and backpressure chambers, reducing leakage and friction, thereby enhancing the overall performance of the compressor.

Implementation Method 1

the collection groove extending not less than 60 degrees and not more than 400 degrees around the axis from the first port to the collection end... allowing for balanced pressure compensation between the compression and backpressure chambers

Methodology Applied
Scientific EffectPressure compensation: Pressure Gradient

Data Source

PatentEP4317691B1Compressor and moving scroll thereof
Publication Date: 2026.01.21 ROBERT BOSCH GMBH
  • EP4317691B1 patent drawingFigure 1~2
  • EP4317691B1 patent drawingFigure 3~4
  • EP4317691B1 patent drawingFigure 5~6

AI summary

The present application provides a compressor and a moving scroll thereof. A moving scroll wall of a moving base plate is integrally formed at a first side of the moving base plate, the moving scroll wall extending around an axis from a position near the axis in a direction away from the axis. A collection groove is disposed on an end face of the moving scroll wall, the end face being located at the end of the moving scroll wall that is opposite the moving base plate in the direction of the axis. A channel running in the direction of the axis is disposed between the collection groove and a second side, the channel and the collection groove being connected at a first port, and the channel running through the second side at a second port. The collection groove extends from the first port to a collection end in a direction towards the centre, and the collection groove extends not less than 60 degrees and not more than 400 degrees around the axis from the first port to the collection end. A compressor using the moving scroll has a suitable cost and high compression efficiency.