Helical Rotor Compressor Layout for Single-Direction Axial Force

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Solution Overview

Problem

Compressors with parallel helical rotors face challenges in achieving a small size while maintaining sufficient displacement, leading to inefficiencies and increased size and cost due to the need for dual thrust bearings to manage unpredictable axial forces.

Innovation Solution

The design incorporates a rotor assembly with rotors having differently shaped portions and air supply holes to generate a preset acting force in a single direction, allowing for a single thrust bearing to manage axial forces, reducing the compressor's size without compromising displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two thrust bearings are arranged to limit axial forces in two directions, then the helical rotors rotate stably, but the compressor size increases

Engineering Contradiction:
Improverotational stabilityVSAvoidcompressor size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies asymmetry by making the rotor structure asymmetric with differently shaped portions (first portion and second portion with different shapes, sizes, or configurations). This asymmetric design creates a preset acting force in a single direction during rotation, eliminating the need for thrust bearings in both directions and reducing compressor size while maintaining rotational stability.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent uses the counterweight principle by designing the rotor portions with different shapes and sizes to generate a preset acting force that counterbalances the axial forces in a predetermined direction. This counterbalancing mechanism eliminates the need for dual thrust bearings and reduces the overall compressor volume.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Volume of moving object

If compressor size is reduced, then the compressor becomes more compact, but displacement becomes insufficient

Engineering Contradiction:
Improvecompressor sizeVSAvoiddisplacement
Core Design Contradiction:
Volume of moving objectVSProductivity

Solution Approach 1:

The patent applies segmentation by dividing the rotor into multiple portions (first portion and second portion) with different shapes and sizes. This segmentation allows each portion to contribute differently to the compression process, maintaining sufficient displacement while the overall rotor assembly fits within a compact compressor volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by giving different portions of the rotor different shapes, sizes, and configurations optimized for their specific functions. The first portion and second portion are designed with local characteristics that maximize displacement efficiency within the limited space, ensuring sufficient productivity despite the reduced overall size.

Inventive Principle:
Principle #3Local quality

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 stabilizes the compressor's operation by reducing the number of thrust bearings, minimizing size and cost, and enhancing mechanical efficiency while reducing lubricating oil demand.

Implementation Method 1

the first portion and/or the third portion is provided with first air supply holes, the second portion and/or the fourth portion is provided with second air supply holes, the first air supply holes and the second air supply holes are configured to be different from each other to generate an air pressure difference during the rotation of the first rotor and the second rotor to form the preset acting force

Methodology Applied
Scientific EffectAir pressure difference: Pressure Gradient

Data Source

PatentEP4239198B1Compressor and air conditioner
Publication Date: 2026.01.28 GREE ELECTRIC APPLIANCE INC OF ZHUHAI
  • EP4239198B1 patent drawingFigure 1~3
  • EP4239198B1 patent drawingFigure 4~5
  • EP4239198B1 patent drawingFigure 6~7

AI summary

A compressor (200), comprising: a first rotor (20) being rotatable around a first axis (11), the first rotor (20) comprising a first portion (22) and a second portion (24); and a first shaft (10) carrying the first portion (22) and the second portion (24), the first shaft (10) having a first end (12) and a second end (14) that are oppositely arranged, wherein the first rotor (20) is configured to be applied with a preset acting force in a direction from the first end (12) toward the second end (14) or from the second end (14) toward the first end (12) during rotation. The size of the compressor (200) can be reduced with the displacement of the compressor (200) remaining substantially unchanged.