Tool Holder-Shank Decoupling for Machining Vibration Reduction

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Solution Overview

Problem

Machining tools, particularly long ones, tend to vibrate during processing, causing unpleasant noise due to resonance in specific frequency ranges, which existing tool arrangements fail to adequately mitigate.

Innovation Solution

The tool arrangement decouples the tool holder and shank by using friction-reducing means, such as an oil film or a spacer with rolling elements, to reduce the coefficient of friction between parallel flat surfaces, allowing each component to vibrate independently and reducing overall vibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If friction-reducing means are introduced between the planar surfaces to decouple vibrations, then vibration perception is reduced, but the device complexity increases

Engineering Contradiction:
Improvevibration perceptionVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces friction-reducing means as an intermediary element between the tool holder and shank planar surfaces. This mediator (oil film, Teflon sheet, or roller bearing) decouples the mechanical connection to reduce vibration transmission while maintaining the basic structural simplicity of the tool holder assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs an oil film as a hydraulic lubrication mechanism to create a friction-reducing interface between the planar surfaces. The oil film acts as a fluid intermediary that minimizes mechanical contact and vibration transmission while maintaining detachable connectivity.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Force

If an oil film is used as friction-reducing means, then friction is reduced to almost zero, but the reliability may be affected by film stability

Engineering Contradiction:
Improvefriction forceVSAvoidconnection reliability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The oil film is treated as a consumable, easily replaceable element. If the oil film degrades or becomes unstable, it can be replenished or replaced without affecting the permanent structural components (tool holder, shank, planar surfaces), thus maintaining reliability through simple maintenance rather than complex design.

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

3Stress or pressure

If the compressibility of friction-reducing means is limited, then axial compression is minimized, but the decoupling effect may be reduced

Engineering Contradiction:
Improveaxial compressionVSAvoidvibration transmission
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The patent carefully selects friction-reducing means with specific compressibility parameters that balance axial load bearing with vibration decoupling. The oil film and Teflon sheet are chosen for their specific elastic properties that allow minimal compression under axial force while maintaining sufficient compliance to reduce vibration transmission effectiveness.

Inventive Principle:
Principle #35Parameter changes

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 approach significantly reduces vibrations in higher frequency ranges, making them imperceptible to the human ear, thereby improving the machining tool's vibration behavior and reducing noise pollution.

Implementation Method 1

friction-reducing means be arranged between the opposing planar surfaces on the tool shank and the tool holder

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

the friction-reducing devices incorporate an axial bearing with rolling elements

Methodology Applied
Scientific EffectRolling friction: Roller

Implementation Method 3

Friction-reducing devices can have an oil film or consist of an oil film. This reduces the friction between the shank and the tool holder in the area of the mating surfaces to almost zero.

Methodology Applied
Scientific EffectFluid lubrication: Lubrication

Implementation Method 4

the spacer includes a receiving body in which rolling elements are accommodated. The rolling elements protrude from at least one of the surfaces of the receiving body facing the planar surfaces and bear against the respective planar surface.

Methodology Applied
Scientific EffectRolling friction: Roller

Data Source

PatentEP3079850B1Tool arrangement and method therefor
Publication Date: 2021.01.13 KOMET GROUP GMBH
  • EP3079850B1 patent drawingFigure 1b~1c
  • EP3079850B1 patent drawingFigure 1a~1d
  • EP3079850B1 patent drawingFigure 2a~2c

AI summary

The invention relates to a tool arrangement (10) comprising a tool holder (12, 112) and a tool (20) having a tool head for processing workpieces and a shaft (24) supporting the tool head, wherein the tool holder (12, 112) and the shaft (24) each have a planar surface (32, 34) oriented transversely with respect to the axial direction of the tool holder and the shaft, the planar surfaces (32, 34) lying opposite one another. The tool holder (12, 112) and the shaft (24) are connected non-rotatably and releasably to one another by connecting means (18, 22, 126) which have a journal (22) projecting in the axial direction and a receptacle (18, 126) which receives the journal (22). According to the invention, between the planar surfaces (32, 34) friction reducing means (36) are disposed which hold the planar surfaces spaced apart from one another and which have, opposite at least one of the planar surfaces (32, 34), a lower coefficient of friction than the planar surfaces (32, 34) in direct contact on one another, and of which the compressibility is not greater than the compressibility of the shaft (24) and not greater than the compressibility of the tool holder (12, 112).