Rolling Mill Roll Elastic Axial Constraint for In-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 mounted on a shaft with elastic means between the shaft and support, allowing for axial movement and realignment during rolling without removing the roll from the stand, and enabling turning directly on the stand by adjusting the preload of the elastic means.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rolls are rigidly axially constrained to the stand, then the rolls can be turned directly on the stand without removal, but the rigid constraint does not allow compensation for knocks or thrust excesses, increasing the risk of breaking and damage
Solution Approach 1:
The roll constraint system transitions from a static rigid connection to a dynamic elastic connection. The spring element allows the roll to move axially in response to forces during rolling operations, while maintaining positional stability during turning operations. This dynamic behavior resolves the contradiction by adapting the constraint stiffness to the operational requirements.
Solution Approach 2:
The elastic constraint system changes the mechanical parameter of axial stiffness. During turning operations, the spring preload maintains sufficient stiffness to prevent roll movement, while during rolling operations, the spring allows controlled axial movement to absorb shocks and misalignments. This parameter change resolves the contradiction between stability during maintenance and flexibility during operation.
2Reliability
If rolls are axially movable with clearance, then misalignments can be compensated reducing break risk, but rolls must be removed for turning and reshaping operations causing lengthy downtime
Solution Approach 1:
The elastic constraint provides continuous axial movement capability without requiring roll removal. The spring element allows the roll to dynamically adjust its position to compensate for misalignments and wear during rolling operations, while maintaining sufficient constraint to enable turning operations in place, eliminating the need for removal and remounting.
Solution Approach 2:
The invention extracts the axial movement function from the mechanical constraint system and implements it through an elastic element. This allows the roll to have axial play for compensation purposes while remaining constrained enough to be turned in place, separating the functions of movement and constraint that were previously mutually exclusive.
3Reliability
If rolls are axially movable, then they can compensate for misalignments, but increased movements during rolling cause leakages of process liquids into the stand components
Solution Approach 1:
The elastic constraint system changes the movement parameter from large uncontrolled axial displacements to small controlled movements within the elastic range of the spring. This limited movement is sufficient to compensate for misalignments while preventing the excessive movements that cause seal failures and liquid leakages into stand components.
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 reduces the risk of damage to rolls and stand components, minimizes downtime, and allows for efficient realignment and turning of rolls within the rolling mill stand, applicable to various rolling mill configurations, including seamless tubes, while maintaining low operational complexity and cost.
Implementation Method 1
a first elastic means (51) and a second elastic means (52) are interposed between said first portion (21) of roll holder shaft (21) and said first hollow support (40) to define an elastic type axial constraint between said roll holder shaft (21) and said first support (40)
Data Source
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.