D-Shaped Strainer Reducing Hydraulic Oil Blow-Back

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Solution Overview

Problem

The existing strainers mounted to oil supply ports in hydraulic oil tanks experience hydraulic oil blow-back during oil supply due to contact with the strainer, which can lead to unreliable liquid surface height confirmation.

Innovation Solution

A strainer design with a bottomed tubular shape and a rod system where the rod is guided along a longitudinal direction, featuring a D-shaped side surface with a notched and curved portion, and a conical bottom surface that prevents oil from passing through, reducing blow-back and allowing accurate liquid surface height confirmation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional strainer is mounted to an oil supply port, then the liquid surface height can be confirmed, but hydraulic oil blow-back occurs during oil supply

Engineering Contradiction:
Improveliquid surface height confirmationVSAvoidhydraulic oil blow-back
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The strainer body is designed with an asymmetric D-shaped cross-section instead of a conventional circular shape. This asymmetric geometry creates a specific flow pattern where the oil jet is directed along the curved surface portion, preventing direct contact with the strainer body and eliminating blow-back while maintaining liquid surface height visibility

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention introduces a vertical dimension to the strainer design by creating a three-dimensional D-shape with a notched portion and curved surface portion. This dimensional change allows the oil flow to follow the curved surface in a specific trajectory, directing it away from the strainer body and preventing blow-back

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the strainer body is made cylindrical for unrestricted installation, then installation flexibility is improved, but liquid blow-back cannot be prevented

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidliquid blow-back
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The strainer body uses a D-shaped asymmetric cross-section that maintains rotational adaptability for unrestricted installation while the specific asymmetric geometry of the notched portion and curved surface portion prevents blow-back by directing oil flow away from the strainer body

Inventive Principle:
Principle #4Asymmetry

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 strainer effectively reduces liquid blow-back and allows for stable and accurate confirmation of the liquid surface height within the tank, while maintaining a cylindrical shape for unrestricted installation.

Implementation Method 1

a float 22 is provided on a distal end on the bottom surface side of the rod. The float, namely, the rod rises and falls as a liquid surface rises and falls.

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

The side surface includes a net body through which the liquid is passable.

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3785785B1strainer
Publication Date: 2023.05.10 YAMASHIN FILTER CORP
  • EP3785785B1 patent drawingFigure 1
  • EP3785785B1 patent drawingFigure 2
  • EP3785785B1 patent drawingFigure 3

AI summary

A liquid surface height inside a tank is allowed to be confirmed while blow-back of a liquid is reduced. A strainer body having a substantially bottomed tubular shape has a substantially D shape when viewed in a longitudinal direction. A bottom surface of the strainer body has a shape in which a part of a substantially conical shape is cut away, and a top of the substantially conical shape overlaps with a notched portion notched to form the substantially D shape. The bottom surface protrudes toward an opening of the strainer body. A rod having a substantially rod shape is provided adjacent to the notched portion of the strainer body, and a float is provided on a lower end of the rod.