Scroll Compressor Spiral Wrap Side Surface Sealing

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Solution Overview

Problem

Conventional scroll compressors face challenges in reducing refrigerant leakage and sliding loss at the side surfaces of spiral wraps due to sliding contact, especially with high-pressure refrigerants like CO2, where existing sealing methods either increase sliding loss or produce wear debris.

Innovation Solution

The implementation of fine depressions on the side surfaces of the spiral wraps of both the fixed and orbiting scrolls, formed by a burnishing tool with rolling elements, to hold lubricating oil and reduce sliding friction, thereby enhancing the seal and efficiency of the compressor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pressing force exerted by a passive crank mechanism is increased to enhance the side-surface seal in spiral wraps, then refrigerant leakage is reduced, but sliding loss increases and wear debris is produced

Engineering Contradiction:
Improveside-surface sealVSAvoidsliding loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention applies local quality by providing fine depressions only on the side surfaces of the spiral wraps where sliding contact occurs, rather than uniformly across the entire surface. This localized modification creates oil-holding reservoirs precisely where lubrication is needed, improving sealing while minimizing energy loss from sliding friction

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fine depressions create a porous-like structure on the side surfaces of the spiral wraps. These micro-depressions capture and retain lubricating oil, allowing it to be gradually released during sliding contact. This porous structure provides continuous lubrication that reduces sliding loss and prevents wear without requiring increased pressing force

Inventive Principle:
Principle #31Porous materials

2Loss of energy

If numerous fine dimples are randomly provided on thrust sliding surfaces by shot peening to reduce friction and wear, then lubrication is improved, but stable sealing effects cannot be expected in sliding contact of spiral wraps

Engineering Contradiction:
ImprovefrictionVSAvoidsealing effect
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention employs asymmetry by creating fine depressions with specific directional orientations on the spiral wrap surfaces, rather than random dimples. The asymmetric arrangement of these depressions is designed to work with the specific sliding motion pattern of the spiral wraps, ensuring both lubrication effectiveness and sealing stability

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The fine depressions are pre-formed on the spiral wrap surfaces during manufacturing, before the compressor operates. This preliminary action ensures that lubricating oil is already positioned in the correct locations to provide immediate lubrication and sealing upon operation, rather than relying on random dimple formation during operation

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 approach effectively reduces refrigerant leakage and sliding loss, improving the compression efficiency of the scroll compressor while maintaining durability and wear resistance of the spiral wraps.

Implementation Method 1

a plurality of fine depressions are provided on one or both of a side surface of the spiral wrap of the fixed scroll and a side surface of the spiral wrap of the orbiting scroll, which are in sliding contact with each other

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2626561B1Scroll compressor and scroll processing method
Publication Date: 2018.09.12 MITSUBISHI HEAVY IND LTD
  • EP2626561B1 patent drawingFigure 1
  • EP2626561B1 patent drawingFigure 2
  • EP2626561B1 patent drawingFigure 3

AI summary

Scroll compressor provided with a compression mechanism (3) that is formed by engaging a paired fixed scroll and orbiting scroll (16, 20) in which spiral wraps (18 and 22) are vertically provided on one surface of end plates thereof, numerous fine depressions (32) are provided on one or both of a side surface (18A, 188) of a spiral wrap (18) of the fixed scroll and a side surface (22A, 22B) of a spiral wrap (22) of the orbiting scroll, which are in sliding contact with each other.