Conical Filter Element With Varying Pleat Height For Hydraulic Fluids

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Solution Overview

Problem

Existing filter elements for fluids, particularly hydraulic fluids, face challenges in achieving high filter performance over a long service life while maintaining a sufficient filter surface area within limited space constraints, often resulting in high pressure loss and turbulence due to uniform filter layer thickness and pleating designs.

Innovation Solution

The filter element features a conical shape with varying outer diameter from the open upper end cap to the closed lower end cap, achieved by locally applying additional filter layers, which optimizes the filter casing structure to adapt to different pressure conditions, ensuring even flow and reduced turbulence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the filter medium is folded or pleated in a zigzag shape to increase filter surface area, then the filter surface area is increased, but the pressure loss and turbulence increase due to uniform filter layer thickness

Engineering Contradiction:
Improvefilter surface areaVSAvoidpressure loss
Core Design Contradiction:
Area of stationary objectVSLoss of energy

Solution Approach 1:

The filter element applies different filter layer thicknesses at different locations along the flow path. The filter medium is applied in multiple passes with increasing thickness toward the outlet, creating locally optimized filtration zones that reduce turbulence and pressure loss while maintaining high filter surface area through pleating

Inventive Principle:
Principle #3Local quality

2Area of stationary object

If additional filter layers are applied to increase filter surface area, then the filter surface area is increased, but the device complexity increases due to multiple application passes

Engineering Contradiction:
Improvefilter surface areaVSAvoidmanufacturing process complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The filter medium application process is segmented into multiple sequential passes, with each pass applying material to a specific thickness range. This systematic segmentation of the manufacturing process enables precise control of filter layer thickness distribution while maintaining operational simplicity through standardized repeated operations

Inventive Principle:
Principle #1Segmentation

3Volume of moving object

If the filter element is designed with limited space constraints, then the compactness is improved, but the filter surface area is reduced

Engineering Contradiction:
Improvefilter element volumeVSAvoidfilter surface area
Core Design Contradiction:
Volume of moving objectVSArea of stationary object

Solution Approach 1:

The filter element utilizes the radial dimension by applying filter layers at different radial distances from the outlet, creating a multi-dimensional thickness profile. This approach maximizes filter surface area within the constrained cylindrical volume by effectively using the radial space that would otherwise be underutilized in uniform thickness designs

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

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

This design enhances filter performance by minimizing pressure loss and turbulence, resulting in high filter efficiency and extended service life, while accommodating varying pressure levels and flow conditions.

Implementation Method 1

filter element for fluids, in particular for hydraulic fluids, consisting of at least one filter casing with at least one folded filter layer

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP2991748B1Filter element
Publication Date: 2021.08.11 HYDAC FILTER SYST
  • EP2991748B1 patent drawingFigure 1
  • EP2991748B1 patent drawingFigure 2~3
  • EP2991748B1 patent drawingFigure 4~5

AI summary

The invention concerns a filter element for fluids, in particular for hydraulic fluid, consisting of at least one foldable filter casing (10) with at least one filter layer (18, 20, 22, 24), which extends between two end caps (26, 32), characterized in that, in order to vary in regions the thickness of the filter casing (10), the height (h1) of each filter fold (12, 44) increases from one end cap (26) to the other end cap (32) or, with the filter fold height (h1) being maintained, the outer diameter (40) of the filter casing (10) varies in the direction of one of the end caps (26, 32).