Dehydrating Oil Refill Cap for Moisture-Safe AC Servicing

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Solution Overview

Problem

Lubricating oils used in air conditioning systems are hygroscopic, leading to humidity absorption in refill containers, which contaminates the coolant and creates corrosive acids when introduced into the cooling circuit, damaging the system.

Innovation Solution

An oil refill container with a dehydrating cap containing drying substances like silica gel, which limits humidity contamination and is designed for quick and cost-effective integration with air conditioning systems, using a hermetically sealed cap and under-cap structure with quick coupling and sealing elements to maintain oil quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the refill container is opened for oil suction operations, then the oil can be refilled into the cooling circuit, but humidity from the air is absorbed by the hygroscopic oil, contaminating it

Engineering Contradiction:
Improveoil refill operationVSAvoidhumidity absorption
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A desiccant substance (silica gel) is introduced as an intermediary element between the oil and the external air environment. The desiccant preferentially absorbs humidity from the air that enters the container during oil suction operations, preventing the hygroscopic oil from absorbing moisture. This mediator approach allows the refill operation to proceed while protecting the oil quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a protected environment within the container by using the desiccant to maintain low humidity conditions. The desiccant continuously absorbs moisture from any air present in the container, effectively creating an inert atmosphere with respect to moisture that prevents chemical reactions between water and the coolant during subsequent operations.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If drying substances are added to protect oil quality, then humidity contamination is reduced, but the container structure becomes more complex

Engineering Contradiction:
Improvehumidity contaminationVSAvoidcontainer structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The desiccant compartment is merged with the existing cap structure of the refill container. The under-cap is designed to house the desiccant substance, integrating the moisture protection function into the closure mechanism rather than adding a separate external device. This integration minimizes structural complexity while achieving the desired protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The desiccant is nested within the cap assembly, specifically in a compartment formed by the under-cap. This nested arrangement allows the drying function to be embedded within the existing container structure, utilizing the cap's internal volume rather than requiring additional external space or components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If a hermetic seal is used to prevent humidity absorption, then oil quality is preserved, but the refill operation becomes more difficult

Engineering Contradiction:
Improvehumidity contaminationVSAvoidrefill operation
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The cap is segmented into multiple functional parts: a hermetic seal to prevent external moisture ingress, and a controlled opening mechanism that allows air (and oil) to pass during refill operations. The under-cap with its desiccant compartment is separated from the main body, allowing independent optimization of sealing and refilling functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The desiccant is pre-positioned in the under-cap compartment before the refill operation begins. This preliminary arrangement ensures that as soon as air enters the container during oil suction, the desiccant immediately begins absorbing moisture, protecting the oil from the start of the refill process without requiring complex real-time control mechanisms.

Inventive Principle:
Principle #10Preliminary action

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 container effectively prevents humidity absorption, preserving oil quality and preventing corrosive acid formation by dehydrating air before refilling, thus protecting the air conditioning system from damage.

Implementation Method 1

the under-cap is adapted to define a compartment suitable for containing at least an amount of a drying substance when it is coupled with said cover... the under-cap is adapted to contain drying substances or means, that is to say, adapted to limit the contamination of the oil by the humidity of the air

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3243677B1Oil refill container
Publication Date: 2018.11.28 MAHLE AFTERMARKET ITAL SPA
  • EP3243677B1 patent drawingFigure 1
  • EP3243677B1 patent drawingFigure 2
  • EP3243677B1 patent drawingFigure 3

AI summary

An oil refill container that can be coupled to a coolant refill station in an air conditioning system for motor vehicles comprises a body (2) defining an oil containment compartment adapted to be mixed with the coolant circulating in said air conditioning system, and a closing cap (3) provided with quick coupling means adapted to be connected to said refill station or a seat adapted to removably connect said quick coupling means to said closing cap, said closing cap comprising a cover and an under-cap (4), wherein the under-cap is adapted to define a compartment (7) suitable for containing at least an amount of a drying substance when coupled to said cover.