Hydrostatic Work Roll Support Using High-Viscosity Water Lubricant

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hydrostatic support methods for work rolls in rolling mills, particularly for high-strength and thin metal strips, face issues with mechanical wear, energy inefficiency, and temperature limitations due to the use of low-viscosity cooling lubricants, leading to inhomogeneous surface quality and increased maintenance costs.

Innovation Solution

A method utilizing single-phase, water-based cooling lubricants with water-soluble additives is applied for both hydrostatic support and lubrication, with adjustable viscosity and temperature to enhance support effectiveness and reduce wear, while also being used for roll gap lubrication and hydraulic systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If low-viscosity cooling lubricants (rolling oil or emulsion) are used for hydrostatic support, then the cooling and lubrication functions are fulfilled, but high flow rates and narrow gaps are required leading to high energy consumption and insufficient support effectiveness

Engineering Contradiction:
Improvecooling effectivenessVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent changes the viscosity parameter of the cooling lubricant from low (conventional rolling oil or emulsion) to high (at least 8 cSt at 40°C). This parameter change allows the use of higher flow rates and wider gaps in the hydrostatic support system, reducing energy consumption while maintaining adequate support effectiveness. The high viscosity enables the lubricant to maintain pressure and support the work roll more effectively without requiring extremely narrow gaps.

Inventive Principle:
Principle #35Parameter changes

2Force

If high flow rates are used to achieve sufficient support forces with low-viscosity lubricants, then support forces are adequate, but pump output and energy consumption increase

Engineering Contradiction:
Improvesupport forceVSAvoidenergy loss
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

By changing the viscosity parameter to high values (at least 8 cSt at 40°C), the patent enables achieving sufficient support forces with lower flow rates. The high viscosity lubricant maintains pressure more effectively, allowing the hydrostatic support system to generate adequate support forces without requiring high flow rates, thus reducing pump output requirements and energy losses.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If mechanical contact support is used for work rolls, then horizontal stability is achieved, but uneven wear of work rolls occurs leading to poor surface quality

Engineering Contradiction:
Improvehorizontal stabilityVSAvoidsurface quality
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical contact support system with a hydrostatic support system using high-viscosity lubricant. Instead of direct mechanical contact between support rollers and work rolls, the support forces are transmitted through the hydrostatic pressure of the lubricant in the gap between support shells and work rolls. This substitution eliminates the uneven wear problem associated with mechanical contact while maintaining horizontal stability of the work rolls.

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

4Temperature

If emulsion is used for cooling and lubrication, then heat capacity is improved, but filterability decreases and biological decomposition occurs

Engineering Contradiction:
Improveheat capacityVSAvoidfilterability and stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter of the cooling lubricant from emulsion (multiphase) to single-phase water-based lubricant with high viscosity (at least 8 cSt at 40°C). This parameter change provides several benefits: single-phase systems are inherently filterable without carrying away lubricant, biological decomposition is eliminated, and the high viscosity compensates for the lower heat capacity compared to emulsions by enabling more effective heat transfer through the lubricant film.

Inventive Principle:
Principle #35Parameter changes

5Manufacturing precision

If smaller work roll diameter is used for high-strength and thin strips, then rolling precision is improved, but horizontal instability increases due to slender roll geometry

Engineering Contradiction:
Improverolling precisionVSAvoidhorizontal stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent applies hydrostatic support using high-viscosity lubricant to provide horizontal stability to slender work rolls. The hydrostatic pressure generated by the high-viscosity lubricant in the narrow gap between support shells and work rolls counteracts the horizontal deflection forces acting on slender rolls. This hydraulic support mechanism enables the use of smaller diameter work rolls for high-precision rolling of high-strength and thin strips without suffering from horizontal instability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 approach provides stable, energy-efficient hydrostatic support with improved heat dissipation and reduced maintenance, maintaining strip flatness and surface quality by optimizing lubricant viscosity and temperature for both support and lubrication functions.

Implementation Method 1

hydrostatic support of work rolls for rolling metallic strips in a rolling mill, using support shells pressed against the work rolls along their length

Methodology Applied
Scientific EffectHydrostatic support: Hydraulic Press

Implementation Method 2

Cooling of rollers and strip (dissipation of forming and frictional heat)

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 3

High heat capacity, good heat transfer

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

Lubrication of the contact surface (establishing suitable tribological conditions in the roll gap)

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3323519B1Method for hydrostatically supporting working rollers for use in cold rolling of high strength and/or thin strips
Publication Date: 2023.01.11 SMS GROUP GMBH

AI summary

Process for the hydrostatic support of work rolls for rolling metallic strips in a rolling mill with supporting shells pressed over the length of the work rolls, into which a single-phase, water-based cooling lubricant mixed with water-soluble forming additives is pressed, in order to thereby provide horizontal hydrostatic and/or hydrodynamic support for the work roll be carried out from one or two sides via the supporting shells.