Scroll Expansion Machine Airflow Passage for Sealing Reliability

Solution Overview

Problem

In scroll expansion machines, high-pressure fluid leakage leads to rust in rotation shafts and bearing devices, lubricant leakage, and emulsification, requiring a large and costly sealing mechanism, which reduces its lifespan.

Innovation Solution

A blower introduces outside air to guide airflow through an air passage around the rotating shaft, directing leaked fluid away from the revolving scroll's backside and towards the outside, preventing rust and lubricant issues, and allowing for cooling of internal components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large-scale sealing mechanism is used to completely seal the sealing surface, then fluid leakage is prevented, but device complexity and cost increase

Engineering Contradiction:

Improvesealing performanceVSAvoidsealing mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces air as an intermediary substance to counterbalance the pressure of leaking high-pressure steam. The air passage system delivers atmospheric pressure air to the backside of the revolving scroll, creating pressure equilibrium that prevents steam from penetrating through the sealing surface into the housing. This mediator approach achieves effective sealing without requiring complex mechanical sealing components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs pneumatic pressure balancing by introducing compressed air (at atmospheric pressure) into the space behind the revolving scroll's sealing surface. The air passage system includes inlet openings, air passages, and outlet openings that regulate air flow to maintain pressure equilibrium. This pneumatic approach replaces complex mechanical sealing with a simpler pressure-based sealing mechanism.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If a large-scale sealing mechanism is used to completely seal the sealing surface, then fluid leakage is prevented, but the lifespan of the sealing mechanism is reduced

Engineering Contradiction:

Improvesealing performanceVSAvoidsealing mechanism lifespan

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent introduces air as an intermediary substance to counterbalance the pressure of leaking high-pressure steam. The air passage system delivers atmospheric pressure air to the backside of the revolving scroll, creating pressure equilibrium that prevents steam from penetrating through the sealing surface into the housing. This mediator approach achieves effective sealing without requiring complex mechanical sealing components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces expensive, complex, short-lived mechanical sealing components with a simple, durable air pressure balancing system. The air passage system consists of basic structural features (inlet openings, air passages, outlet openings) that are inherently durable and require no replacement, effectively eliminating the lifespan limitation associated with mechanical seals.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Device complexity

If steam leakage is allowed to occur, then device complexity is reduced, but rust and lubricant emulsification occur

Engineering Contradiction:

Improvesealing mechanism complexityVSAvoidrust and lubricant degradation

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of steam leakage into a beneficial pressure balancing mechanism. Instead of preventing all steam leakage, the system allows controlled steam penetration and counterbalances it with atmospheric pressure air. The leaked steam itself becomes part of the pressure equilibrium system, and its condensation is directed away from sensitive components through the air flow, preventing rust and lubricant degradation while maintaining simple device structure.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces air as an intermediary substance to counterbalance the pressure of leaking high-pressure steam. The air passage system delivers atmospheric pressure air to the backside of the revolving scroll, creating pressure equilibrium that prevents steam from penetrating through the sealing surface into the housing. This mediator approach achieves effective sealing without requiring complex mechanical sealing components.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If the sealing surface is completely sealed, then fluid leakage is prevented, but cost increases

Engineering Contradiction:

Improvesealing performanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent introduces air as an intermediary substance to counterbalance the pressure of leaking high-pressure steam. The air passage system delivers atmospheric pressure air to the backside of the revolving scroll, creating pressure equilibrium that prevents steam from penetrating through the sealing surface into the housing. This mediator approach achieves effective sealing without requiring complex mechanical sealing components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces expensive, complex, short-lived mechanical sealing components with a simple, durable air pressure balancing system. The air passage system consists of basic structural features (inlet openings, air passages, outlet openings) that are inherently durable and require no replacement, effectively eliminating the lifespan limitation associated with mechanical seals.

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

Prevents rust and lubricant leakage, maintains component reliability by directing leaked fluid outside, and simplifies the sealing mechanism, reducing maintenance and operational costs.

Implementation Method 1

a blower that introduces outside air into the air passage from the inlet opening, wherein airflow is formed via the air passage from the inlet opening to the outlet opening

Methodology Applied

Scientific EffectAirflow: Convection

Implementation Method 2

the energy of the high pressure fluid expanding in the expansion process is used for revolving a revolving scroll

Methodology Applied

Scientific EffectExpansion: Phase Change

Implementation Method 3

when the steam flows out of the expansion chamber and condenses into water

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS8562317B2Scroll expansion machine with air flow passage around outer periphery of sealing surface

Publication Date: 2013.10.22 ANEST IWATA CORP

AI summary

The rotating shaft is connected to the generator; the high-pressure steam s is introduced to the expansion chamber b through the guide passage; when the energy of the high-pressure steam s during expansion process revolves the revolving scroll, the generator regenerates electric power. The connecting housing is provided with the inlet opening and the outlet opening; the ventilation blades are fitted to the rotating shaft. When the ventilation blades rotate, the outside air is introduced (inside of the housing) from and through the inlet opening; the air passes by the air opening and the backside of the revolving scroll, and is discharged through the outlet opening. Thus, by the approach that the air passage is formed inside of the connecting housing and the scroll housing, the high-pressure steam s is prevented from being directed toward the backside of the revolving scroll.