Cylindrical Ceramic Bars in Roll Journal Thrust Bearings

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Solution Overview

Problem

Current roll journal assemblies in continuous hot-dipping processes face issues such as inconsistent wedge pressure leading to ceramic bar cracking, dross trapping causing premature wear, and equipment failure due to localized heating and vibration, resulting in increased maintenance costs and safety risks.

Innovation Solution

A roll journal assembly with semi-cylindrical slots and cylindrical ceramic bars, eliminating the need for wedges and using a thrust bearing insert with a cylindrical ceramic bar and protection cover to reduce friction and dross trapping, and a thrust sleeve with a flanged end to dampen side thrusts, ensuring stable operation and extended equipment life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rectangular ceramic bars are used with wedges to limit displacement, then the ceramic bars are constrained in place, but the wedges subject the ceramic bars to localized heating and inconsistent pressure leading to cracking and breaking

Engineering Contradiction:
Improvestability of ceramic barsVSAvoidcracking and breaking of ceramic bars
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces rectangular ceramic bars with cylindrical ceramic bars. The cylindrical shape eliminates sharp edges and corners that concentrate stress, resulting in more uniform stress distribution during rotation and under thermal loading. This geometric change prevents the cracking and breaking that occurs with rectangular bars when subjected to wedge pressure and localized heating.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent eliminates the wedge component entirely from the design. By using cylindrical ceramic bars that fit directly into the clamp structure, the need for wedges to secure the ceramic bars is removed. This extraction of the harmful wedge element prevents localized heating from welding operations and inconsistent pressure application that cause ceramic bar failure.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If rectangular ceramic bars are used, then friction is limited during rotation, but dross is trapped between the bars and clamp causing scoring and premature wear

Engineering Contradiction:
Improvefriction reductionVSAvoiddross trapping and scoring
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The cylindrical shape of the ceramic bars creates smooth, continuous surfaces that allow dross particles to roll off rather than become trapped. Unlike rectangular bars with flat surfaces and corners where dross can accumulate, the curved surface of cylindrical bars prevents dross entrapment, eliminating the scoring and premature wear that results from dross accumulation between the bars and clamp.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Adaptability or versatility

If stainless steel clamps with rectangular ceramic bars are used, then the roll journal assembly can operate in molten zinc, but equipment failure occurs due to ceramic bar breakage and sleeve damage

Engineering Contradiction:
Improveoperation in molten zincVSAvoidequipment lifespan
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The cylindrical ceramic bars provide superior reliability in molten zinc operation compared to rectangular bars. The curved geometry eliminates stress concentration points, prevents dross trapping, and ensures smooth rotation without vibration. This design prevents the cascade of failures including ceramic bar breakage, journal vibration, and sleeve damage that occur with rectangular bar designs.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent employs a composite design combining stainless steel clamp material with ceramic bearing material in a cylindrical configuration. This composite structure leverages the corrosion resistance of stainless steel for clamp integrity and the low-friction, high-temperature stability of ceramic material for rotation, creating a system that maintains reliability in the aggressive molten zinc environment.

Inventive Principle:
Principle #40Composite materials

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

The solution enhances the stability and longevity of roll journal assemblies by preventing ceramic bar cracking, reducing dross-related wear, and minimizing equipment downtime, thereby improving operational efficiency and safety.

Implementation Method 1

the rectangular ceramic bars function to limit friction during rotation

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a thrust bearing insert with a cylindrical ceramic bar and protection cover to reduce friction and dross trapping, and a thrust sleeve with a flanged end to dampen side thrusts

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3237771B1Thrust bearing and clamp in roll journal assembly
Publication Date: 2020.04.15 ARCELORMITTAL SA
  • EP3237771B1 patent drawingFigure 1
  • EP3237771B1 patent drawingFigure 2
  • EP3237771B1 patent drawingFigure 3

AI summary

Modified thrust bearing inserts and clamps (100) using ceramic cylindrical bars (110) for submerged roll assemblies in a continuous hot-dipping apparatus are provided.