Device for grinding or milling and method for sealing such a device

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Solution Overview

Problem

Existing devices for crushing or grinding hard, brittle materials face issues with reliable sealing of the passage opening for the drive shaft, leading to contamination of the ground material due to the rubbing off of coatings or flocking from the foam seals during relative movement.

Innovation Solution

A device with a sealing ring and a cutting ring, where the cutting ring is positioned in an annular slot of the sealing ring, creating a labyrinth seal that prevents contamination by generating a cutting movement between the sealing ring and the cutting ring, and is connected to the tool or drive shaft to ensure effective sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If foam seals with coatings or flocking are used to reduce friction, then the seal can operate with lower friction, but the coating or flocking rubs off due to relative movement and contaminates the ground material

Engineering Contradiction:
Improvefriction reductionVSAvoidcontamination of ground material
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The seal is divided into multiple functional components: a foam seal base, a friction-reducing coating layer, and a protective cage structure. This segmentation allows each layer to perform its specific function while protecting the ground material from contamination by the rubbing-off coating particles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The friction-reducing coating acts as an intermediary between the foam seal and the ground material, reducing direct friction while the cage structure serves as another intermediary to capture and contain any coating particles that may rub off, preventing them from contaminating the ground material.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the drive shaft and tool move relative to the foam seal, then the seal can accommodate movement, but the relative movement causes coating or flocking to rub off and penetrate into the container

Engineering Contradiction:
Improveaccommodation of relative movementVSAvoidpenetration of coating particles into container
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The cage structure is nested around the foam seal with the friction-reducing coating, creating a protective enclosure. This nested configuration allows the inner components to move relative to each other while the outer cage contains any particles that may be generated, preventing penetration into the container.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The relative movement that causes coating to rub off is converted into a beneficial effect by the cage structure, which captures the rubbed-off particles and redirects them away from the container, transforming a harmful contamination source into a controlled containment system.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If a seal is used to close the passage opening, then the passage opening is sealed, but ground material can still pass through the gap between the seal and drive shaft

Engineering Contradiction:
Improvesealing of passage openingVSAvoidpassage of ground material through gap
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sealing approach is extended from a single-dimensional foam seal to a multi-dimensional system including the radial foam seal, the cylindrical cage structure, and the friction-reducing coating layer. This dimensional expansion creates multiple barriers that collectively prevent ground material from passing through the gap between the seal and drive shaft.

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

The solution provides a reliable and effective seal that prevents the passage of ground material through the gap, even when finely comminuting or grinding, by enhancing the contact surface and reducing friction, thus minimizing contamination of the ground material.

Implementation Method 1

a friction-reducing coating is applied to the cutting ring to avoid friction between the cutting ring and the sealing ring

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3512391B1Device for grinding or milling and method for sealing such a device
Publication Date: 2020.08.05 IKA WERKE GMBH & CO KG
  • EP3512391B1 patent drawingFigure 1~2
  • EP3512391B1 patent drawingFigure 3~4
  • EP3512391B1 patent drawingFigure 5~6

AI summary

The aim of the invention is to improve the sealing of a device for grinding or milling material to be ground. To this end, the invention relates to a device (1) and to the method for sealing particularly such a device (1). According to the invention, the seal (10) of the device (1) comprises the sealing ring (11) which radially surrounds the drive shaft (6) and the cutting ring (12) arranged between the sealing ring (11) and the tool (5). In order to produce the seal (10), the cutting ring (12) is set into the sealing ring (11) and positioned in the annular slit (14) created by this action, said cutting ring being connected to the tool (5) and/or the drive shaft (6) such that the passage (7) is sealed.