Adjustable Hydraulic Tensioning for Web Winding Force Measurement

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Solution Overview

Problem

Existing devices for measuring contact pressure in the nip between a rocker arm and a reel drum require pre-tensioning, which decreases over time due to vibrations and heat changes, leading to inaccurate measurements and cumbersome readjustment, especially when mechanical tensioning elements are used and the force measuring device is exposed to environmental influences.

Innovation Solution

The tensioning force for the oscillating lever against the force measuring device can be adjusted during operation using adjustable hydraulic or pneumatic cylinders, eliminating the need for pre-tensioning and allowing for continuous adjustment of clamping force, with the force measuring device optionally protected from environmental factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical tensioning elements are used to pre-tension the rocker arm against the force measuring device, then constant contact is ensured and continuous signal is supplied, but the prestress decreases over time due to vibrations and heat changes, leading to inaccurate measurements

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidprestress stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by replacing static mechanical tensioning elements with a dynamic control system. The force measuring device is integrated into the oscillating lever, and the preload is actively controlled through a control unit that adjusts the position of the oscillating lever based on measured values, ensuring stable contact pressure despite vibrations and temperature changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control where the control unit continuously monitors the measured values from the force measuring device and adjusts the position of the oscillating lever accordingly. This closed-loop system maintains accurate measurements by compensating for changes in contact pressure caused by vibrations, heat, or other environmental factors.

Inventive Principle:
Principle #23Feedback

2Reliability

If mechanical tensioning elements are used to pre-tension the rocker arm, then contact is maintained, but the clamping elements are difficult to access and readjusting the preload is cumbersome

Engineering Contradiction:
Improvecontinuous contactVSAvoidreadjustment ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the mechanical tensioning system with an integrated force measuring device that is part of the oscillating lever assembly. This eliminates separate clamping elements that are difficult to access, and the preload can be adjusted through the control system without manual intervention in hard-to-reach locations.

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

3Device complexity

If the force measuring device is exposed to environmental influences such as dust or temperature fluctuations, then the device structure is simpler, but measurement precision deteriorates

Engineering Contradiction:
Improvedevice structureVSAvoidcontact pressure measurement
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges the force measuring device with the oscillating lever structure, integrating it into the existing mechanical assembly. This integration protects the force measuring device from environmental influences by incorporating it within the protected space of the oscillating lever, while maintaining measurement precision through the control system's compensation capabilities.

Inventive Principle:
Principle #5Merging (Combining)

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 ensures precise and stable contact pressure measurement throughout the winding process, simplifies installation and readjustment, and allows for optimal tensioning based on fiber material type, maintaining accurate measurements without the need for constant preloading.

Implementation Method 1

the clamping element is an adjustable hydraulic cylinder. The clamping force can then also be adjusted during operation in a particularly simple manner via the pressure in the hydraulic cylinder

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the clamping element can be formed by an adjustable pneumatic cylinder

Methodology Applied
Scientific EffectPneumatic pressure: Gas Compressor

Implementation Method 3

the force is measured between the oscillating lever and a stationary counterpart via a force measuring device

Methodology Applied
Scientific EffectForce measurement: Force

Data Source

PatentEP2253567B1Device for continuously rolling up a web of fibrous material
Publication Date: 2013.07.10 ANDRITZ AG
  • EP2253567B1 patent drawingFigure 1
  • EP2253567B1 patent drawingFigure 2
  • EP2253567B1 patent drawingFigure 3

AI summary

The invention relates to a device for the continuous winding of a fibrous web (1), in particular a paper web, for example a tissue web, wherein the fibrous web (1) is guided over a support drum (2) mounted on rocker arms (4) and subsequently wound onto a winding device (5), and the contact force in the nip (24) between the paper roll (16) and the support drum (4) is measured by means of a force measuring device (7), wherein the rocker arm (4) can be clamped against the force measuring device (7) via a clamping element (8). It is primarily characterized in that the clamping force for clamping the rocker arm (4) against the force measuring device (7) is adjustable via the clamping element (8).