Scroll Compressor Flank Deviation for Leakage Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing scroll compressors face challenges in maintaining consistent internal clearances during operation, leading to varying leakage rates and pressure losses due to deformations caused by pressure and temperature changes, which affect efficiency and predictability of performance.

Innovation Solution

The design incorporates adapted flank sections on the stator and rotor scrolls with initial deviations that account for deformations, ensuring instantaneous final clearances are closer to ideal values, reducing variation and leakage, by making the flanks non-perpendicular at rest and deforming them to fit more closely during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the internal clearances are made small to reduce leakage and pressure loss, then efficiency is improved, but the risk of contact between rotor scroll and stator scroll increases

Engineering Contradiction:
Improveleakage rate and pressure lossVSAvoidrisk of contact between rotor scroll and stator scroll
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-deforming the rotor and stator scrolls during manufacturing so that their flanks are already positioned closer together at rest. When the compressor operates and thermal expansion occurs, the flanks naturally move to the ideal parallel position, preventing contact while maintaining small clearances. This anticipates the thermal deformation and compensates for it in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameters of the scroll flanks by intentionally creating non-perpendicular angles and non-parallel positions during manufacturing. These parameter changes in the initial geometry allow the flanks to transform into the desired parallel configuration during operation due to thermal expansion and operational deformations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the internal clearances are made large to prevent contact between rotor scroll and stator scroll, then reliability is improved, but leakage rate and pressure loss increase

Engineering Contradiction:
Improveprevention of contact between rotor scroll and stator scrollVSAvoidleakage rate and pressure loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by pre-deforming the rotor and stator scrolls during manufacturing so that their flanks are already positioned closer together at rest. When the compressor operates and thermal expansion occurs, the flanks naturally move to the ideal parallel position, preventing contact while maintaining small clearances. This anticipates the thermal deformation and compensates for it in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameters of the scroll flanks by intentionally creating non-perpendicular angles and non-parallel positions during manufacturing. These parameter changes in the initial geometry allow the flanks to transform into the desired parallel configuration during operation due to thermal expansion and operational deformations.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the flanks are made perpendicular and parallel at rest, then manufacturing precision is simplified, but the final internal clearances during operation vary significantly due to deformations

Engineering Contradiction:
Improvesimplicity of manufacturingVSAvoidconsistency of final internal clearances
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-deforming the rotor and stator scrolls during manufacturing so that their flanks are already positioned closer together at rest. When the compressor operates and thermal expansion occurs, the flanks naturally move to the ideal parallel position, preventing contact while maintaining small clearances. This anticipates the thermal deformation and compensates for it in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameters of the scroll flanks by intentionally creating non-perpendicular angles and non-parallel positions during manufacturing. These parameter changes in the initial geometry allow the flanks to transform into the desired parallel configuration during operation due to thermal expansion and operational deformations.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If the flanks are made non-perpendicular with initial deviations, then the final internal clearances during operation become more consistent, but manufacturing complexity increases

Engineering Contradiction:
Improveconsistency of final internal clearancesVSAvoidcomplexity of manufacturing
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-deforming the rotor and stator scrolls during manufacturing so that their flanks are already positioned closer together at rest. When the compressor operates and thermal expansion occurs, the flanks naturally move to the ideal parallel position, preventing contact while maintaining small clearances. This anticipates the thermal deformation and compensates for it in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameters of the scroll flanks by intentionally creating non-perpendicular angles and non-parallel positions during manufacturing. These parameter changes in the initial geometry allow the flanks to transform into the desired parallel configuration during operation due to thermal expansion and operational deformations.

Inventive Principle:
Principle #35Parameter changes

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 approach results in more predictable and consistent final internal clearances, reducing leakage and pressure losses, thereby enhancing the efficiency and reliability of the scroll compressor.

Implementation Method 1

the pressures of course change significantly, as it is the intention to compress air or gas, as do the temperatures in the scroll compressor. These changes of pressures and temperatures in the scroll compressor are accompanied by a deformation of the stator scroll and the rotor scroll

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

These changes of pressures and temperatures in the scroll compressor are accompanied by a deformation of the stator scroll and the rotor scroll, whereby the local internal clearances in the scroll compressor change as a result of such deformations

Methodology Applied
Scientific EffectPressure deformation: Deformation

Data Source

PatentEP2956673B1Scroll compressor.
Publication Date: 2019.05.01 ATLAS COPCO AIRPOWER NV
  • EP2956673B1 patent drawingFigure 1
  • EP2956673B1 patent drawingFigure 2
  • EP2956673B1 patent drawingFigure 3

AI summary

Scroll compressor (1) with a stationary, stator scroll (8) and a movable rotor scroll (16) and a drive to move the rotor (6), whereby in each position places are formed with an instantaneous minimum opening (29) between the rotor scroll (16) and the stator scroll (8) whereby at each height (2) in a minimum opening (29) there is a local transverse internal clearance (S), whereby at least one of the stator flanks (10/11) or rotor flanks (18,19) comprises an adapted flank section (37-40) with an initial local stator flank deviation (ΔΤ0i, AT0u) or rotor flank deviation (ΔR0i/ AR0u) that is different to zero at each point when the rotor (6) is stationary, and during nominal operation of the scroll compressor corresponding instantaneous final local stator flank deviations (ΔTfi, ΔTfu) or rotor flank deviations (ΔRfi, ΔRfU) whose absolute values are smaller.