Compressor Sealing Channel Throttle for Lower Leakage and Axial Force

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Solution Overview

Problem

Existing compressors face challenges in achieving effective sealing between compressor stages, leading to increased axial forces on the rotor, leakage, and higher resistance to rotation due to inefficient sealing channels.

Innovation Solution

The compressor design incorporates a throttle section within the sealing channel, positioned closer to the low-pressure region, and features an asymmetrical sealing edge or groove to reduce leakage and axial forces, with the throttle section strategically placed to minimize pressure drop and enhance sealing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing channel is provided between compressor stages, then sealing between stages is achieved, but leakage increases and axial forces on the rotor increase

Engineering Contradiction:
Improvesealing between compressor stagesVSAvoidleakage through sealing channel
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent introduces a throttle section with a reduced cross-sectional area within the sealing channel, creating a localized pressure drop. This parameter change in the channel geometry transforms the sealing mechanism by establishing a pressure differential that prevents medium leakage while reducing axial forces on the rotor.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sealing channel is designed with a localized throttle section that has different cross-sectional area compared to other sections. This local quality change creates a specific pressure distribution pattern where the throttle section experiences higher pressure differential, effectively preventing leakage without requiring the entire channel to be tightly sealed.

Inventive Principle:
Principle #3Local quality

2Reliability

If a sealing channel is provided between compressor stages, then sealing between stages is achieved, but resistance to rotation of the rotor increases

Engineering Contradiction:
Improvesealing between compressor stagesVSAvoidrotational resistance of rotor
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

By introducing a throttle section with controlled cross-sectional area, the patent creates a localized pressure drop that reduces the overall pressure differential acting on the rotor surface. This parameter change in the channel geometry reduces the drag force on the rotor, lowering rotational resistance while maintaining sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If sealing channel geometry is optimized to reduce leakage, then leakage decreases, but pressure drop across the channel increases

Engineering Contradiction:
Improveleakage through sealing channelVSAvoidpressure drop across sealing channel
Core Design Contradiction:
Loss of substanceVSStress or pressure

Solution Approach 1:

The patent applies local quality by creating a throttle section with reduced cross-sectional area at a specific location within the sealing channel. This localized geometry change concentrates the pressure drop effect in one region, allowing the rest of the channel to maintain larger dimensions that facilitate smoother flow and reduce overall resistance to rotation.

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 configuration reduces leakage and axial forces on the rotor while maintaining low resistance to rotation, improving the overall sealing performance and efficiency of the compressor.

Implementation Method 1

the throttling section is arranged closer to the low-pressure area of the first compressor chamber than to the second. This also improves the pressure drop across the sealing channel.

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP3224480B1Compressor having a sealing channel
Publication Date: 2023.07.05 ROBERT BOSCH GMBH
  • EP3224480B1 patent drawingFigure 1~2
  • EP3224480B1 patent drawingFigure 3~4
  • EP3224480B1 patent drawingFigure 5~6

AI summary

The invention relates to a compressor, which has a housing and a rotor, wherein the rotor has a compressor wheel at least on one side, wherein a compressor chamber is formed between the compressor wheel and the housing, wherein the rotor is rotatably supported, wherein an annular sealing channel is formed between the rotor and the housing, wherein the sealing channel is led from the compressor chamber to a region having a lower pressure, wherein a throttle segment is provided in the sealing channel, wherein the throttle segment is arranged closer to the low-pressure region than to the compression chamber.