Sealed Chuck Jaw Drive Structure Against Coolant and Dirt Ingress

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Solution Overview

Problem

Chucks for machine tools are prone to failure due to the ingress of liquids and dirt, which can cause blocking of the driving jaw units and increase downtimes.

Innovation Solution

A chuck design featuring a flat sealing element that moves radially with the driving jaw units, engaging with the base body projection to cover the passage opening and prevent liquids and dirt from entering the guide pocket, combined with sealing elements and grooves to ensure effective sealing and prevent tilting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a through-opening connects the guide groove and guide pocket, then the drive jaw unit can move radially, but liquids and dirt can penetrate into the guide pocket causing blocking

Engineering Contradiction:
Improveradial movement of drive jaw unitVSAvoidingress of liquids and dirt
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A flat sealing element made of flexible material is positioned in the guide groove to seal the through-opening. The sealing element can deform elastically to accommodate the radial movement of the drive jaw unit while maintaining the seal, preventing liquids and dirt from entering the guide pocket through the opening.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing element is designed to be radially movable along with the drive jaw unit. As the drive jaw unit moves radially between clamping and release positions, the sealing element moves dynamically with it, maintaining continuous sealing of the through-opening throughout the movement range.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a sealing element is added to prevent ingress, then protection against liquids and dirt improves, but device complexity increases

Engineering Contradiction:
Improveprotection against blockingVSAvoidadditional sealing components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing element is integrated into the existing guide groove structure rather than being a separate complex assembly. The flat sealing element utilizes the existing radial space and movement path of the drive jaw unit, combining the sealing function with the existing mechanical structure to minimize additional complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sealing element is designed as a simple, inexpensive flat component that can be easily replaced if worn. This simple design approach reduces the complexity and cost of the sealing solution while maintaining effective protection against liquids and dirt ingress.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If the sealing element is fixed, then sealing effectiveness improves, but the drive jaw unit cannot move radially

Engineering Contradiction:
Improvesealing effectivenessVSAvoidradial movement range
Core Design Contradiction:
Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

The sealing element is designed to be radially movable along with the drive jaw unit. As the drive jaw unit moves radially between clamping and release positions, the sealing element moves dynamically with it, maintaining continuous sealing of the through-opening throughout the movement range.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The flat sealing element is made of flexible material that can deform and move radially while maintaining its sealing function. This flexibility allows the sealing element to accommodate the radial movement of the drive jaw unit without compromising the seal against liquid and dirt ingress.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3639955B1Chuck for machine tools
Publication Date: 2021.02.24 SCHUNK GMBH & CO KG
  • EP3639955B1 patent drawingFigure 1
  • EP3639955B1 patent drawingFigure 2
  • EP3639955B1 patent drawingFigure 3

AI summary

The invention relates to a chuck (1) for machine tools with a chuck body (2) defining a chuck axis (X), which has several guide grooves (4) extending radially to the chuck axis (X) in its front end face (3) for receiving clamping jaws (5), wherein each guide groove (4) is associated with a drive jaw unit (6) which is movable in a guide pocket (8) arranged behind the guide groove (4) in the chuck body (2) parallel to the guide groove (4) and extends axially through an elongated through-opening (9) connecting the guide groove (4) and the guide pocket (8) and projects into the guide groove (4), wherein each drive jaw unit (6) comprises a drive jaw (11) which can be engaged via a front toothing (12) with a mating toothing (12) of a clamping jaw (5), wherein a sealing element movable radially with the drive jaw units (6) is located in each guide groove (4). (32) is provided for,which rests against the base of the groove and has a central recess (33) into which the drive jaw unit (6) engages.