Spindle Device Coil Unit Relocation for Compact Tool Holder

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Solution Overview

Problem

Spindle devices with electrical consumers on the tool holder side face challenges of bulky structure and inefficient energy transmission due to coil configurations, making tool changes difficult and energy transfer less efficient.

Innovation Solution

The spindle device features a coil unit positioned away from the tool holder, with a vibration unit attached to the tool holder for axial, radial, or rotational vibrations, and full-circumferential coils for efficient energy transmission, allowing for a compact and efficient design without compromising energy transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the coil unit is arranged on the tool holder side with the electrical consumer, then the energy supply is direct, but the structure becomes bulky and tool changes become difficult

Engineering Contradiction:
Improveenergy supply to electrical consumerVSAvoidstructural complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The coil unit is extracted from the tool holder side and relocated to the spindle rotor side, separating the energy transmission component from the tool holder. This extraction eliminates the bulky structure on the tool holder while maintaining the energy supply function through the rotating interface between spindle and tool holder.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spindle rotor acts as an intermediary carrier that transports energy from the stationary coil unit to the rotating tool holder via magnetic coupling. This intermediary approach enables energy transmission without direct mechanical connection, simplifying the overall structure while maintaining functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the coil configuration uses a segment of a circle to facilitate tool change, then tool changes are easier, but the energy transmission efficiency deteriorates

Engineering Contradiction:
Improvetool change easeVSAvoidenergy transmission efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

Instead of modifying the coil shape to a segment to facilitate tool changes, the invention inverts the approach by keeping the coil unit complete and stationary on the spindle rotor, while the tool holder rotates into position. This inversion maintains full energy transmission efficiency while enabling easy tool changes through rotational positioning.

Inventive Principle:
Principle #13The other way round (Inversion)

3Device complexity

If the coil unit is positioned away from the tool holder, then the structure becomes compact and coils are protected, but the energy transmission distance increases

Engineering Contradiction:
Improvestructural compactnessVSAvoidenergy transmission loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The mechanical proximity requirement is replaced by electromagnetic field coupling between the coil unit and the electrical consumer. This substitution allows the coil unit to be positioned optimally for structural compactness and protection while maintaining efficient energy transmission through the electromagnetic field across the rotational interface.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration results in a simpler, more compact spindle device that facilitates easy tool changes and maintains high energy transfer efficiency, protecting the coils from damage and dirt, and enables effective machining of composite materials by reducing fringing on workpieces.

Implementation Method 1

a coil unit (140) for supplying electrical energy to the at least one electrical consumer

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the electrical load has a vibration unit (160) attached to the tool holder (14) in a rotationally fixed manner, which is set up to drive a vibration of the tool holder (14) in the axial direction of the spindle device

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentEP3221082B1Spindle device and machine tool having a spindle device
Publication Date: 2022.06.22 DMG MORI ULTRASONIC LASERTEC GMBH
  • EP3221082B1 patent drawingFigure 1A
  • EP3221082B1 patent drawingFigure 1B
  • EP3221082B1 patent drawingFigure 1C

AI summary

The invention relates to a spindle device (100), comprising: a tool holder (14) for holding a tool or a tool interface; a spindle drive comprising a spindle rotor (130) for rotationally driving the tool holder (14); an electrical load (160), which is arranged on the side of the spindle rotor (130) facing the tool holder (14); and a coil unit (140) for supplying electrical energy to the electrical load (160); wherein the coil unit (140) is arranged on the side of the spindle rotor (130) facing away from the tool holder (14).