Rotary Compressor Vane Segmentation for Leakage and Friction Trade-off

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Solution Overview

Problem

Refrigerating cycle apparatuses with rotary compressors face challenges in minimizing leakage loss of gas refrigerant while maintaining smooth roller movement without increasing sliding loss, due to the partial contact of vanes with rollers, which affects compression efficiency and reliability.

Innovation Solution

The solution involves dividing the vane into two stacked vanes, optimizing the minute gap between the cylinder and vane height dimensions to ensure a proportion of 0.001 < L / (number of divided vanes) / H < 0.0015, allowing for dispersed contact force and reduced friction, thereby restraining sliding and leakage losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the proportion of the minute gap to the vane height dimension is set too small, then the leakage loss is reduced, but the movement of the vane is worsened and the sliding loss is increased

Engineering Contradiction:
Improveleakage lossVSAvoidsliding loss
Core Design Contradiction:
Loss of substanceVSLoss of energy

Solution Approach 1:

The vane is divided into two separate vanes stacked in the height direction. This segmentation allows the contact force between the roller and vanes to be distributed across two separate contact surfaces, reducing the sliding loss while maintaining an appropriate minute gap proportion for preventing excessive leakage loss.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the proportion of the minute gap to the vane height dimension is set too large, then the movement of the vane is improved, but the amount of leaked gas refrigerant is increased and the leakage loss is increased

Engineering Contradiction:
Improvevane movementVSAvoidleakage loss
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

Dividing the vane into two stacked vanes allows for optimizing the minute gap proportion. The segmented structure reduces the contact pressure on each individual vane, improving ease of movement while the stacked configuration maintains adequate sealing to prevent excessive refrigerant leakage.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If one vane is provided, then the structure is simple, but the contact force on the sliding surface is concentrated and the sliding friction is increased

Engineering Contradiction:
Improvevane structureVSAvoidsliding friction
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The single vane is segmented into two stacked vanes. This increases device complexity slightly but significantly reduces sliding friction by distributing the contact force from the roller across two separate contact surfaces, thereby reducing the concentrated stress and friction on a single vane.

Inventive Principle:
Principle #1Segmentation

4Loss of energy

If the vane is divided into two vanes, then the contact force is dispersed and sliding friction is reduced, but the leakage loss may increase due to the additional gap

Engineering Contradiction:
Improvesliding frictionVSAvoidleakage loss
Core Design Contradiction:
Loss of energyVSLoss of substance

Solution Approach 1:

The vane is divided into two stacked vanes with each having height H. The total height of the two vanes is controlled to maintain the minute gap proportion L/H between 0.001 and 0.0015. This segmentation disperses contact force to reduce sliding friction while the controlled gap proportion prevents excessive refrigerant leakage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The parameter of the minute gap proportion L/H is precisely controlled to be between 0.001 and 0.0015. This parameter optimization ensures that the dispersed contact force from the two stacked vanes reduces sliding friction while the maintained gap proportion prevents excessive leakage loss.

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 configuration enhances the reliability and efficiency of the rotary compressor by minimizing leakage and sliding losses, ensuring effective refrigerant compression and smooth roller movement without compromising performance.

Implementation Method 1

a roller moves eccentrically within the cylinder chamber

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

contact force on a sliding surface between the roller and the divided vane can be dispersed and sliding friction can be restrained

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2884108B1Rotary compressor and refrigeration cycle apparatus
Publication Date: 2018.11.07 TOSHIBA CARRIER CORP
  • EP2884108B1 patent drawingFigure 1
  • EP2884108B1 patent drawingFigure 2~3
  • EP2884108B1 patent drawingFigure 4~5

AI summary

A rotary compressor accommodating an electric motor portion and a compression mechanism portion joined to the electric motor portion through a rotation axis in a sealed case, wherein the compression mechanism portion comprises a cylinder comprising a cylinder chamber, a roller moving eccentrically within the cylinder chamber, and a vane abutting the roller and partitioning an inside of the cylinder chamber into a compression chamber and an intake chamber. The vane is disposed by stacking two divided vanes in a height direction of the cylinder, which is an axis direction of the rotation axis, and where a height dimension of one divided vane is H, and a minute gap between a height dimension of the cylinder and a height dimension of the two stacked divided vanes is L, a proportion of the minute gap L to the vane height dimension H per one divided vane is 0.001&lt;L/number of divided vanes/H&lt;0.0015.