Ring Spinning Machine Drafting Roller Length Compensation

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Solution Overview

Problem

Ring spinning machines with machine-length drafting systems face issues of torsional and linear expansion stresses in lower roller strands, leading to distortion errors and operational disruptions due to uneven torque distribution and heat-related expansions.

Innovation Solution

The implementation of a length compensation device with a balance shaft and a receptacle forming a positive shaft-hub connection, specifically a P4C polygon profile, which allows for both torque transmission and linear expansion compensation along the entire length of the lower roller strands, ensuring reliable drive connection and heat-related expansion compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If machine-length lower roller strands are used in drafting units, then the drafting capability and productivity are improved, but torsional stress and distortion defects occur during acceleration and deceleration

Engineering Contradiction:
Improvedrafting capabilityVSAvoidyarn quality consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The lower roller strand is divided into multiple roller sections (at least two) that can be independently positioned along the longitudinal axis. This segmentation allows each section to be independently driven or positioned, reducing torsional stress accumulation across the entire length while maintaining the machine-length drafting capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The roller sections are made dynamically positionable along the longitudinal axis of the lower roller strand, allowing the system to adapt to varying torque conditions during acceleration and deceleration. This dynamic adjustment prevents distortion defects by optimizing the torque distribution in real-time.

Inventive Principle:
Principle #15Dynamics

2Power

If powerful electric motors are used to drive machine-length lower roller strands, then the drafting power and speed are improved, but thermal expansion of the drafting rollers occurs

Engineering Contradiction:
Improvedrafting powerVSAvoidroller temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

Dividing the long lower roller strand into multiple sections reduces the total length of each individual roller, thereby reducing the cumulative thermal expansion effect while maintaining the overall drafting power through coordinated operation of multiple sections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces longitudinal positioning capability as an additional degree of freedom, allowing roller sections to move along the longitudinal axis to compensate for thermal expansion effects, thus decoupling the power transmission function from the thermal expansion problem.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple auxiliary drives are arranged along the lower roller strands, then torsional stress is reduced, but the device complexity increases

Engineering Contradiction:
Improvetorque distribution uniformityVSAvoiddrive system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lower roller strand is segmented into multiple independently controllable sections, each capable of receiving drive torque. This segmentation provides multiple torque entry points without requiring complex auxiliary drive mechanisms, as each section can be driven by the main drive through simple power transmission elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The roller sections serve multiple functions: they transmit drafting torque, compensate for thermal expansion through longitudinal movement, and reduce torsional stress by distributing the drive torque along the length of the lower roller strand, eliminating the need for separate auxiliary drives.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Force

If rigid connections are used between roller segments, then torque transmission is improved, but linear expansion compensation is prevented

Engineering Contradiction:
Improvetorque transmissionVSAvoidexpansion compensation capability
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The connection between roller sections is made dynamically adjustable, allowing rigid torque transmission during normal operation while permitting longitudinal movement to accommodate thermal expansion. The sections can be positioned at different locations along the lower roller strand while maintaining torque transmission capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By segmenting the lower roller strand into independently positionable sections, the system achieves both rigid torque transmission within each section and flexible expansion compensation between sections through longitudinal repositioning capability.

Inventive Principle:
Principle #1Segmentation

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 design ensures consistent torque transmission and immediate compensation for linear expansions, reducing the risk of torsional and linear stress-related damages, thereby enhancing the operational stability and quality of the yarn production by preventing thin or thick spots and thread breaks.

Implementation Method 1

upper rollers rest on the lower roller strands. These upper rollers are driven by the lower roller strands via frictional engagement

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the drafting rollers of the lower roll strands are not only subjected to relatively high torsional stress due to the applied torque, but also often undergo thermal expansion of the drafting rollers due to heating

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3670718B1Ring spinning machine with drafting units
Publication Date: 2023.04.19 SAURER SPINNING SOLUTIONS GMBH & CO KG
  • EP3670718B1 patent drawingFigure 1
  • EP3670718B1 patent drawingFigure 2
  • EP3670718B1 patent drawingFigure 3

AI summary

The invention relates to a ring spinning machine (1) with drafting units (10) formed by pairs of rollers (21, 22, 23) rotating at different speeds and comprising machine-length lower roller strands (21u, 22u, 23u) composed of partially grooved roller segments (34, 48, etc.) and each equipped with a length compensation device (31). According to the invention, the length compensation devices (31) integrated into the lower roller strands (21u, 22u, 23u) are designed and arranged such that both length compensation and torque transmission are possible with respect to the lower roller strands (21u, 22u, 23u).