Scroll Compressor Brush Positioning for Abrasion Control

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Solution Overview

Problem

In scroll-type fluid machines, abrasion powders generated by the sliding of conductive components can intrude into the compression chamber, compromising the reliability of the compressor due to wear and dust intrusion.

Innovation Solution

A scroll-type fluid machine design that positions the slide surface for conductive brushes away from the cooling air path, preventing abrasion powders from entering the compression chamber and improving the reliability of the compressor by using conductive brushes to manage static electricity and reduce wear on the face seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conductor is provided at the shaft end to discharge static electricity, then static electricity damage is prevented, but abrasion powders are generated and scattered into the compression chamber

Engineering Contradiction:

Improveprotection from static electricity damageVSAvoidabrasion powders scattered into compression chamber

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A conductive brush is introduced as an intermediary component between the conductor and the orbiting scroll. The conductive brush contacts the orbiting scroll surface to discharge static electricity, while the holder positions it to minimize abrasion powder generation and scattering into the compression chamber.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The conductor is separated from direct contact with the orbiting scroll by extracting its contact function into a dedicated conductive brush component. This allows the conductor to perform its static electricity discharge function while the brush design controls abrasion powder generation.

Inventive Principle:

Principle #2Taking out (Extraction)

2Temperature

If the cooling fan is provided to cool the fixed scroll and orbiting scroll, then cooling effect is achieved, but cooling air scatters abrasion powders into the compression chamber

Engineering Contradiction:

Improvecooling of fixed scroll and orbiting scrollVSAvoidabrasion powders scattered by cooling air into compression chamber

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The holder acts as an intermediary structure that positions the conductive brush in a location where cooling air can still reach the scrolls for cooling, but the brush's controlled contact minimizes abrasion powder generation in the cooling air path, preventing powder scattering into the compression chamber.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the face seal is provided to prevent dust intrusion, then seal reliability is improved, but wear occurs due to abrasion powders from the conductor

Engineering Contradiction:

Improvedust prevention capability of face sealVSAvoidservice life of face seal due to wear

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The conductive brush with holder serves as an intermediary that provides controlled electrical contact to discharge static electricity while minimizing uncontrolled sliding and abrasion powder generation, thereby reducing wear on the face seal and extending its service life.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The conductive brush is designed as a consumable component that can be easily replaced. By using a replaceable brush instead of a permanent conductor structure, the system accepts periodic replacement of this simple component to protect the more critical and expensive face seal from wear.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 design effectively reduces the intrusion of abrasion powders into the compression chamber, enhancing the reliability and longevity of the compressor by preventing dust and wear-related issues, while maintaining efficient cooling and electrical conductivity.

Implementation Method 1

an orbiting bearing causing the drive shaft to be supported on the orbiting scroll

Methodology Applied

Scientific EffectLubrication: Lubrication

Implementation Method 2

a cooling fan supplying cooling air into an interior of the casing

Methodology Applied

Scientific EffectForced Convection: Forced Convection

Implementation Method 3

an orbiting scroll side conductive brush causing the orbiting scroll and the casing to be conducted

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentUS9790943B2Scroll-type fluid machine with grease-lubricated orbiting bearing

Publication Date: 2017.10.17 HITACHI IND EQUIP SYST CO LTD

AI summary

A scroll-type fluid machine reduces intrusion of abrasion powders, generated by sliding of a conductor causing an orbiting scroll side and a fixed scroll side to be conducted, into a compression chamber, and improves reliability of a compressor. The scroll-type machine includes a casing, a fixed scroll having a flange surface attached to the casing, and a wrap portion provided at an end plate, an orbiting scroll having a wrap portion provided at the end plate, and provided in an opposed relationship with the fixed scroll, a drive shaft connected through a crank portion to the orbiting scroll, an orbiting bearing, a face seal portion arranged between the orbiting scroll and the fixed scroll, a cooling fan, and an orbiting scroll side conductive brush.