Linear Motor Thread Guide with Adjustable Stator Gap

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Solution Overview

Problem

Existing thread guide devices for winding units face challenges with high energy consumption and wear due to the need to accelerate and move large masses at high speeds, as well as premature bearing wear from magnetic forces, which limits their operational efficiency and requires frequent repairs.

Innovation Solution

The thread guide device incorporates positioning means to adjust the normal distance between the rotor and stator parts, allowing for a force-free positioning that reduces friction and wear, using adjustable guide rods and actuators such as electromagnetic, electromechanical, or thermal actuators to optimize the runner's position and minimize energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the thread guide is designed as a rotor of a linear motor with permanent magnets, then high speeds and accelerations can be achieved, but magnetic forces cause premature bearing wear and damage

Engineering Contradiction:
Improvewinding speedVSAvoidbearing durability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

A non-magnetic intermediary material (such as ceramic or plastic) is introduced between the permanent magnets of the rotor and the bearing components. This intermediary shields the bearing from direct exposure to strong magnetic forces while allowing mechanical support and motion guidance to continue, thereby preventing premature bearing wear caused by magnetic attraction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If roller bodies are used to support the rotor, then the rotor can move back and forth, but large mass must be accelerated and high energy consumption results

Engineering Contradiction:
Improverotor mobilityVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The heavy roller bodies are replaced by a lightweight linear bearing system that allows the rotor to move directly along guide rails or ways. This extraction of the massive rolling components eliminates the need to accelerate large masses, significantly reducing energy consumption while maintaining the rotor's back-and-forth mobility through low-friction linear motion.

Inventive Principle:
Principle #2Taking out (Extraction)

3Power

If the runner is positioned close to stator parts for efficient magnetic coupling, then motor efficiency improves, but friction and wear on slide bearings increase

Engineering Contradiction:
Improvemotor efficiencyVSAvoidfriction and wear
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The bearing system is designed with dynamic adjustment capabilities, allowing the optimal gap between the runner and stator parts to be maintained during operation. This dynamic positioning ensures efficient magnetic coupling for high motor efficiency while preventing excessive friction and wear by avoiding too-close positioning that would cause mechanical contact and bearing degradation.

Inventive Principle:
Principle #15Dynamics

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 solution significantly reduces energy consumption and wear on the slide bearings, enabling higher speeds and accelerations while minimizing machine downtime by maintaining the runner in an optimal, force-free position, thus enhancing the operational efficiency and longevity of the thread guide device.

Implementation Method 1

at least the first stator part being designed to generate a traveling magnetic field in which the rotor moves back and forth along the stator as a result of its at least one permanent magnet

Methodology Applied
Scientific EffectTraveling magnetic field: Electromagnetic Propulsion

Implementation Method 2

the runner moves in the traveling field along the at least one stator part as a result of its at least one permanent magnet

Methodology Applied
Scientific EffectMagnetic field interaction: Lorentz Force

Implementation Method 3

The friction can be greatly reduced by positioning the runner between the stator parts as optimally as possible

Methodology Applied
Scientific EffectFriction reduction: Friction

Implementation Method 4

by specifically generating a magnetic field, the soft-magnetic bending element can then be used to adjust the guide rod and thus the rotor can be positioned accordingly

Methodology Applied
Scientific EffectMagnetic field actuation: Electromagnetic Propulsion

Data Source

PatentEP2238061B1Slidingly mounted thread guide
Publication Date: 2012.02.29 LUNATONE INDUSTRIELLE ELEKTRONIK GMBH
  • EP2238061B1 patent drawingFigure 1
  • EP2238061B1 patent drawingFigure 2
  • EP2238061B1 patent drawingFigure 3

AI summary

The invention relates to a thread guide device (VOR) for a spool unit (SEI) for winding product to be wound (GUT) onto a spool (SPU) of the spool unit (SEI), wherein the thread guide device comprises a thread guide, which carries out a back and forth movement during winding, and wherein the thread guide is configured as a rotor (LAU) of an electric linear motor (LIN), and wherein the rotor (LAU) is displaceably mounted between a first stator part (STA1) and a second stator part (STA2) that is disposed opposite thereof, wherein at least one of the two stator parts (STA1) is provided for generating a travelling magnetic field, and wherein the rotor (LAU) comprises at least one permanent magnet (PEM), such that the rotor (LAU) can move in the travelling field along the at least one stator part (STA1). According to the invention, the rotor (LAU) is displaceably mounted between the first stator part (STA1) and the second stator part (STA2) in a sliding bearing (GLL) parallel to the two stator parts (STA1, STA2), and positioning means (POS) for varying the normal distance of the rotor (LAU) to at least one of the two stator parts (STA1, STA2) are provided.