Compressor Oil Retaining Means Capillary Action

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Solution Overview

Problem

Conventional compressors face oil shortages due to vibration-induced oil surface oscillations and insufficient oil supply, leading to inefficient lubrication and refrigerant contamination.

Innovation Solution

A compressor design featuring an oil supply system with an oil retaining means that utilizes capillary action to collect and retain oil, ensuring stable oil supply to the compression mechanism even when the oil surface falls below the suction port, preventing oil shortages and splashing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a relatively large amount of oil is stored in the oil reservoir to prevent short supply, then the oil supply to sliding portions is improved, but the rotor is dipped in the oil reservoir causing oil to splash and generate bubbles, leading to temporary shortage of oil in the discharged refrigerant

Engineering Contradiction:
Improveoil supply stabilityVSAvoidoil amount in discharged refrigerant
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

An oil retaining member is introduced as an intermediary component between the oil reservoir and the suction port. This member retains oil through capillary action and surface tension, preventing direct contact between the rotor and bulk oil while ensuring continuous oil supply to the suction port. The oil retaining member acts as a buffer that supplies oil steadily without allowing the rotor to dip into and splash the oil reservoir.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The oil retaining member utilizes porous material properties to retain oil through capillary action. The porous structure allows the member to hold oil within its pores while permitting controlled release to the suction port, preventing both oil shortage and excessive oil carryover with the refrigerant.

Inventive Principle:
Principle #31Porous materials

2Ease of manufacture

If the suction port is positioned at a higher level for easier manufacturing, then the manufacturing process is simplified, but the oil surface may fall below the suction port during operation causing short supply of oil

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidoil supply continuity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The oil retaining member serves as an intermediary that decouples the position of the suction port from the oil surface level. By placing the oil retaining member at the suction port location, oil is retained and supplied reliably regardless of whether the suction port is positioned at a higher or lower level, thus maintaining manufacturing simplicity while ensuring oil supply continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The oil retaining member performs preliminary oil retention and preparation before oil reaches the suction port. This preliminary action ensures that oil is already retained and ready for supply, preventing any potential short supply issues that would occur if the suction port were positioned above the oil surface during operation.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If capillary force is used instead of pump power for oil supply, then the device complexity is reduced, but insufficient oil supply occurs

Engineering Contradiction:
Improveoil supply system complexityVSAvoidoil supply amount
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The oil retaining member utilizes self-service through capillary action and surface tension to retain and supply oil without requiring external pump power. The porous structure and surface properties of the oil retaining member enable it to automatically retain and release oil based on capillary forces, providing a simple yet effective oil supply mechanism that achieves both reduced device complexity and sufficient oil supply amount.

Inventive Principle:
Principle #25Self-service

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 solution ensures a consistent and sufficient oil supply to the compressor's sliding portions, preventing lubrication failures and refrigerant contamination, while allowing for a compact design that can be manufactured on the same line as vertical compressors without significant redesign.

Implementation Method 1

an oil supply system with an oil retaining means that utilizes capillary action to collect and retain oil

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2884106B1Compressor
Publication Date: 2018.01.31 MITSUBISHI ELECTRIC CORP
  • EP2884106B1 patent drawingFigure 1~2
  • EP2884106B1 patent drawingFigure 3~4
  • EP2884106B1 patent drawingFigure 5~7

AI summary

It is an object to provide a compressor which can supply a relatively large amount of oil while preventing shortage of the oil. The compressor includes a sealed container (40), a rotary shaft (2) supported in the sealed container (40), a compression mechanism (20) that compresses a refrigerant upon rotation of the rotary shaft (2), an oil supply conduit (2a) that is formed inside the rotary shaft (2), and allows the oil supplied to the compression mechanism (20) to flow through it, an oil reservoir (11 provided inside the sealed container (40) in its lower portion, oil retaining means (17) having a part disposed in the oil reservoir (11) and the remaining part disposed in the gas space above the oil reservoir (11), and containing a large number of voids to retain the oil, and an oil supply pipe (10) having its one port connected to the oil supply conduit (2a), and its other port disposed in the oil reservoir (11).