Spinning Rotor Speed Control via Acceleration Time Analysis

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Solution Overview

Problem

Open-end rotor spinning devices with single-motor drives face challenges in ensuring operational reliability and preventing damage from incorrect rotor speeds, particularly due to varying rotor diameters affecting centrifugal forces and yarn parameters.

Innovation Solution

A method where the spinning rotor is accelerated from a first speed to a second speed, with the acceleration time recorded and evaluated as an evaluation variable to identify the rotor diameter, limiting the permissible speed to prevent damage, and displaying warnings if deviations occur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a large spinning rotor is used to spin thicker yarn, then the yarn fineness range is improved, but the permissible rotational speed decreases due to higher centrifugal forces

Engineering Contradiction:
Improveyarn fineness rangeVSAvoidpermissible rotational speed
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The system performs preliminary identification of the spinning rotor's diameter and shape characteristics before operation begins. The control system stores reference values for different rotor types and pre-determines the permissible rotational speed limits based on the identified rotor characteristics, preventing damage from excessive speed before it occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the operational parameters (permissible rotational speed) based on the identified rotor characteristics (diameter, shape). The control system adjusts the speed limits dynamically according to the specific rotor type installed, allowing optimal operation for each rotor configuration while preventing damage from inappropriate speed settings.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If rotational speed is monitored to detect malfunctions, then operational reliability is improved, but the detection precision is insufficient because speed deviations are significantly smaller than energy input deviations

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmalfunction detection precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The invention replaces mechanical speed monitoring with an electrical measurement approach. By monitoring the electrical energy input to the motor driving the spinning rotor, the system detects malfunctions with much higher precision, as electrical deviations are significantly larger and more easily measurable than mechanical speed deviations.

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

Solution Approach 2:

The invention introduces an intermediary measurement approach by monitoring the electrical energy consumption as an indirect indicator of rotor condition. Instead of directly measuring rotor speed or mechanical parameters, the system uses electrical energy input as a mediator to detect bearing contamination and other malfunctions with superior precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If identification marks are automatically detected to configure spinning stations, then quality assurance is improved, but additional hardware and system complexity are required

Engineering Contradiction:
Improvequality assuranceVSAvoidhardware and system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces mechanical or optical identification mark detection systems with an electrical measurement-based identification method. By measuring the acceleration characteristics and electrical energy consumption of the rotor, the system automatically identifies rotor type and configures spinning parameters without requiring additional sensors, markers, or complex detection hardware.

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 method enhances operational safety by ensuring the spinning rotor operates within safe speed limits, preventing damage and ensuring compatibility with set yarn and spinning parameters, without requiring additional hardware beyond existing control devices and software adaptations.

Implementation Method 1

The invention is based on the understanding that acceleration depends on the diameter of the spinning rotor. A smaller spinning rotor accelerates faster than a larger one due to its lower moment of inertia.

Methodology Applied
Scientific EffectMoment of Inertia: Moment of Inertia

Implementation Method 2

a single-motor drive (3) for driving the spinning rotor (2)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3305952B1Open end rotor spinning device and method for operating an open end rotor spinning device
Publication Date: 2020.07.29 SAURER SPINNING SOLUTIONS GMBH & CO KG
  • EP3305952B1 patent drawingFigure 1
  • EP3305952B1 patent drawingFigure 2~3

AI summary

The present invention relates to a method for operating an open-end rotor spinning device (1) with an interchangeable, individually motor-driven spinning rotor (2). According to the invention, the spinning rotor (2) is accelerated from a first speed (n1) to a second speed (n2), and the acceleration time (tA, tB) required for the acceleration from the first speed (n1) to the second speed (n2) is recorded and evaluated as a parameter. Alternatively, the spinning rotor (2) is accelerated from a first speed (n1) for a predetermined acceleration time (tA, tB), and the second speed (n2) reached during this time is recorded and evaluated as a parameter. The invention further relates to the open-end rotor spinning device (1).