Impulse Scraper Lip Bending Zones for Adherent Particle Removal

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Solution Overview

Problem

Existing wiper arrangements in hydraulic systems, such as those in cranes and construction machinery, often fail to reliably remove strongly adhering foreign particles like ice or dried dirt from piston rods, leading to contamination of bearing gaps and potential damage.

Innovation Solution

A pulse scraper with an elastically deformable wiper lip featuring annular grooves that create a bending zone, allowing for a mechanical wiping impulse to dislodge adherent foreign bodies, combined with a support element to counteract tilting moments and enhance wiping force, and optionally a second scraper lip with opposite direction of action for increased effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional wiper lip is used, then the wiper can remove loose foreign particles, but it cannot reliably remove strongly adhering foreign bodies like ice or dried-on contaminants

Engineering Contradiction:
Improvereliability of foreign body removalVSAvoidstructural complexity of wiper lip
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The wiper lip is designed to be elastically deformable, transforming from a static structure to a dynamic one that can adapt its shape during operation. The elastic deformation allows the wiper lip to conform to the piston rod surface and generate sufficient contact pressure to remove strongly adhering foreign bodies without requiring a complex rigid mechanism

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The annular grooves create a bending zone that changes the mechanical parameters of the wiper lip by defining a specific region for elastic deformation. This parameter change in the structural configuration enables the wiper lip to achieve the necessary flexibility and wiping impulse while maintaining manufacturing simplicity

Inventive Principle:
Principle #35Parameter changes

2Force

If the wiper lip is made more rigid to increase wiping force, then it can remove stronger adhesions, but it cannot adapt to surface variations and generate sufficient contact pressure

Engineering Contradiction:
Improvewiping forceVSAvoidadaptability to piston rod surface
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The elastic deformability of the wiper lip enables it to dynamically adapt to variations in the piston rod surface geometry while maintaining sufficient contact pressure. The material's elastic properties allow the wiper lip to conform to surface irregularities and generate the necessary normal force for effective wiping of strongly adhering foreign bodies

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If a one-piece metal wiper structure is used, then manufacturing is simple, but it cannot provide the necessary elastic deformation for reliable foreign body removal

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidforeign body removal effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The wiper lip is designed as an elastic component that can be integrated into the holding section, combining the simplicity of a largely one-piece construction with the functional benefits of elastic deformation. The elastic material allows the wiper lip to deform and generate wiping impulse while maintaining ease of manufacture through integration, avoiding complex assembly of multiple rigid parts

Inventive Principle:
Principle #30Flexible shells and thin films

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 pulse scraper effectively removes strongly adhering foreign particles, preventing their entry into bearing gaps and enhancing the longevity and reliability of wiper arrangements, particularly in critical applications where malfunction could cause injury or damage.

Implementation Method 1

the wiper lip is elastically deformable and has one or more annular grooves on its circumferential side facing away from the holding section, each of which defines a desired bending zone of the wiper lip

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

each of which defines a desired bending zone of the wiper lip, wherein the wiper lip itself forms a functional axial stop for a longitudinal segment of the wiper lip arranged distal to the axial stop

Methodology Applied
Scientific EffectStress concentration:

Implementation Method 3

a wiper lip with a wiper edge circumferentially extending relative to the central axis of the impulse wiper for dynamically contacting and removing the foreign body from the counter-running surface

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4430326B1Impulse scraper and scraper assembly
Publication Date: 2025.01.15 TRELLEBORG SEALING SOLUTIONS GERMANY GMBH
  • EP4430326B1 patent drawingFigure 1~2
  • EP4430326B1 patent drawingFigure 3
  • EP4430326B1 patent drawingFigure 4~5

AI summary

The invention relates to an impulse scraper (20) and a scraper assembly for scraping a foreign body (19) off the counter running surface (28) of a machine part. The impulse scraper comprises a retaining section and a scraper lip (24) with a scraper edge (26), extending circumferentially relative to the central axis (Z) of the impulse scraper, for dynamically contacting and scraping the foreign body (19) off the counter running surface (28). The scraper lip is elastically deformable and, on the peripheral side pointing away from the retaining section (22), it has one or more preferably annular area(s) of weakened material, each defining a target bending zone (36) of the scraper lip (24), wherein, with the scraper lip (24) itself, a functional axial stop (38) is formed for a respective longitudinal segment (24a, 24b) of the scraper lip (24) arranged distally from the axial stop (38). Alternatively, the scraper lip (24) is arranged on a support element (44) and the axial deflection movement thereof relative to the retaining section (22) is limited by an at least functional axial stop. The invention also relates to a scraper assembly (10).