Rotary Compressor Vane Slot Discharge Port Design

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Solution Overview

Problem

In rotary compressors, particularly of the hinge vane type, the increased side pressure between the vane and the vane slot leads to friction loss and side wear, reducing compressor efficiency and reliability. Additionally, refrigerant residual spaces can cause refrigerant pressure to rise above discharge pressure, further exacerbating these issues.

Innovation Solution

A rotary compressor design where the discharge port is strategically positioned to overlap with the vane, is wider than the discharge guide groove, inclined towards the vane, and eccentrically disposed relative to the discharge guide groove. This configuration allows the refrigerant residual space to communicate with the discharge port, ensuring that residual refrigerant is discharged, thereby preventing pressure buildup and reducing side pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the vane is hinge-coupled to the roller to achieve stable vane behavior, then axial leakage is reduced, but side pressure increases causing friction loss and side wear

Engineering Contradiction:
Improvevane behavior stabilityVSAvoidfriction loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The vane is divided into two separate components: the vane body and the vane holder. The vane body is detachably coupled to the roller, while the vane holder is separately coupled to the vane slot. This segmentation allows the vane body to maintain stable hinge-coupled behavior with the roller, reducing axial leakage, while the separate vane holder minimizes contact with the vane slot, reducing side pressure and friction loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vane holder acts as an intermediary component between the vane body and the vane slot. It provides a dedicated mounting structure that reduces the contact area and pressure between the vane assembly and the vane slot, thereby reducing side wear and friction loss while maintaining the stability of the vane behavior.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the vane is hinge-coupled to the roller, then axial leakage is reduced, but side wear increases due to increased side pressure

Engineering Contradiction:
Improveaxial leakage reductionVSAvoidvane service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

By segmenting the vane into vane body and vane holder, the design maintains the hinge-coupled connection for axial leakage reduction while minimizing the contact between the vane holder and vane slot, thereby reducing side wear and extending vane service life.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vane holder is designed with specific local properties: a reduced contact area with the vane slot and optimized material characteristics. This local quality modification reduces side pressure and wear at the critical interface while maintaining the overall structural integrity and leakage prevention functions.

Inventive Principle:
Principle #3Local quality

3Productivity

If refrigerant remains in the refrigerant residual space, then compression is completed, but pressure buildup occurs exceeding discharge pressure

Engineering Contradiction:
Improvecompression completionVSAvoidrefrigerant pressure
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The discharge port is strategically positioned and sized to enable preliminary discharge of refrigerant from the refrigerant residual space before pressure buildup occurs. The discharge port configuration ensures that residual refrigerant is continuously evacuated, preventing pressure from exceeding discharge pressure and avoiding the need for additional pressure relief mechanisms.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If the discharge port is positioned to overlap with the vane, then residual refrigerant discharge is improved, but device complexity increases

Engineering Contradiction:
Improveresidual refrigerant dischargeVSAvoiddischarge port configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The discharge port is designed to serve multiple functions simultaneously: it enables primary discharge of compressed refrigerant, facilitates residual refrigerant discharge from the refrigerant residual space, and maintains proper spacing from the vane to prevent interference. This multi-functionality is achieved through strategic positioning and sizing rather than additional components, avoiding increased device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 proposed design effectively suppresses the increase in side pressure between the vane and the vane slot, reduces friction loss and side wear, and enhances the reliability of the compressor by preventing refrigerant pressure in residual spaces from exceeding discharge pressure.

Implementation Method 1

A rotary compressor compresses refrigerant using a roller performing an orbiting movement in a compression space of a cylinder

Methodology Applied
Scientific EffectMechanical compression: Compression

Implementation Method 2

a vane in contact with an outer circumferential surface of the roller to partition the compression space of the cylinder into a plurality of spaces

Methodology Applied
Scientific EffectMechanical partitioning:

Implementation Method 3

The rotary compressor generates a gas force in the compression space during the compression process, and the vane receives a force in a width direction by the gas force

Methodology Applied
Scientific EffectGas pressure force: Pressure Increase

Implementation Method 4

cylinder reaction forces acting in opposite directions while being orthogonal to the vane slot are generated on inner and outer circumferential sides of the vane slot. This pair of cylinder reaction forces act as a couple of forces

Methodology Applied
Scientific EffectMechanical reaction force: Force

Implementation Method 5

a side surface of the vane and a sidewall surface of the vane slot may be pressed against each other to cause friction loss or side wear while increasing side pressure

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3851676B1Rotary compressor
Publication Date: 2025.02.05 LG ELECTRONICS INC
  • EP3851676B1 patent drawingFigure 1
  • EP3851676B1 patent drawingFigure 2
  • EP3851676B1 patent drawingFigure 3(a)~3(f)

AI summary

A rotary compressor according to the present disclosure may include at least one cylinder in which a discharge guide groove is disposed at one side of a vane slot; a roller orbitably provided in the cylinder, and disposed with a hinge groove on an outer circumferential surface thereof; a vane in which one end portion thereof is rotatably inserted into the hinge groove of the roller, and the other end portion thereof is slidably inserted into the vane slot of the cylinder; and a plurality of bearing plates that seals both side surfaces of the cylinder, and at least one side of which is disposed with a discharge port to communicate with the discharge guide groove, wherein the discharge port communicates with a refrigerant residual space defined between the vane slot and the discharge guide groove. Through this, refrigerant in the refrigerant residual space may be discharged even after the roller passes through the discharge guide groove.