Rolling Mill Roll Elastic Axial Constraint for On-Stand Turning

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Solution Overview

Problem

Existing rolling mill stands face challenges with rolls that are either rigidly axially constrained, leading to potential damage from knocks and misalignments, or axially movable, which requires costly and complex removal and reshaping processes, resulting in increased downtime and risk of damage.

Innovation Solution

The implementation of an elastic constraint system for rolls, where at least one roll is rigidly mounted on a shaft with elastic means providing axial support, allowing for realignment and turning without removal, and adjustable preload to manage axial forces during rolling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If rolls are rigidly axially constrained to the stand, then they can be turned directly on the stand without removal, but they are subjected to increased risk of breaking and damage from knocks and thrust excesses

Engineering Contradiction:
Improveroll turning operationVSAvoidroll damage risk
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies the dynamics principle by transitioning from a rigid axial constraint to a dynamic elastic constraint system. The roll holder shaft is mounted on elastic means (such as springs or elastomeric elements) that allow controlled axial movement. This dynamic system enables the roll to absorb axial thrusts and knocks during operation while maintaining sufficient constraint for turning operations, thereby resolving the contradiction between ease of manufacture and reliability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If rolls are axially movable to compensate for misalignments, then the risk of breaks and damage is reduced, but they require removal and remounting for turning operations which is lengthy and complicated

Engineering Contradiction:
Improvemisalignment compensationVSAvoidroll removal and remounting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies the self-service principle by designing a system where the roll automatically realigns itself during operation through the elastic constraint mechanism. The elastic means allow the roll holder shaft to move axially and self-correct misalignments without external intervention. This eliminates the need for manual removal and remounting for realignment, reducing downtime while maintaining the reliability benefits of misalignment compensation.

Inventive Principle:
Principle #25Self-service

3Reliability

If rolls are axially movable to realign during rolling, then misalignments are compensated, but the union of roll profiles deviates from the defined shape and increased movements cause leakages of process liquids

Engineering Contradiction:
Improvemisalignment compensationVSAvoidprocess liquid leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies the parameter changes principle by carefully controlling the stiffness and preload parameters of the elastic constraint system. The elastic means are designed with specific mechanical properties that allow sufficient movement for misalignment compensation while maintaining enough constraint to preserve the roll profile geometry. This balanced parameter selection prevents excessive movement that would cause profile deviation and process liquid leakage, while still providing the reliability benefits of misalignment compensation.

Inventive Principle:
Principle #35Parameter changes

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 enables axial movement and realignment of rolls during rolling, reduces the risk of damage, and allows for turning on the stand without disassembly, while being cost-effective and reducing operational complexity.

Implementation Method 1

elastic means (51, 52) interposed between said first portion (21) of roll holder shaft (20) and said first hollow support (40)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3573773B1Rolling mill stand with rolls axially constrained with elastic system
Publication Date: 2021.04.21 DANIELI & C OFFICINE MECCANICHE SPA
  • EP3573773B1 patent drawingFigure 1
  • EP3573773B1 patent drawingFigure 2
  • EP3573773B1 patent drawingFigure 3

AI summary

A rolling mill stand for rolling rod-shaped bodies, in particular tubular bodies, said stand comprising at least three rolls (10) mutually arranged to define a rolling pass line for said rod-shaped and/or tubular bodies, wherein at least one of said three rolls (10) is rigidly mounted on a roll holder shaft (20), freely fixed in turn in a rotational manner to said stand by means of a first hollow support (40) and a second hollow support (30) arranged on opposite sides of said at least one roll (10), respectively, wherein a first portion (21) and a second portion (22) of said roll holder shaft (20) are housed in said first hollow support (40) and in said second hollow support (30), respectively, where the constraint between at least said first hollow support and said first portion (21) of the roll holder shaft is of elastic type.