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ECRS/METALOCK

Tom DurbinProfessional Engineer Mechanical Engineering

Louisiana State University

President

Engineered Casting Repair Services, Inc.and

Metalock® Corporation, Inc.

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“The Technology Leaders in the Crack Repair Industry”

Specializing in

Casting Repair & Restoration

Including

Failure Analysis

Casting Design & Redesign

Repair of Cracked & Damaged Castings

and

Field & Shop Machining

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Utilizing

• Our Proven METALOCK® Mechanical Repair Techniques.

• State of the Art Engineering and Metallurgy.

• Finite Element Computer Modeling and Stress Analysis.

• Over 150 Years of Combined Experience.

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Examples

• Rack Gear Repair on a Bucyrus, Model 1570W Dragline.

• Repair of Cracked Pintel on Large Dragline.• Repair of Trunnion/Head on a Ball Mill.• Repair of Ball Mill Trunnion at Gold Mine.• Cracked Gear Case on Coal Pulverizer.• Stress Analysis of Cracked Walking Eccentric

on Large Dragline.

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Rack Gear Repair On Bucyrus Model 1570W Dragline

This Rack Gear Segment was found to be cracked in the roots of three adjacent teeth. The worst of these cracks extended almost completely across the width of the gear along the root of the tooth, thru the 4 ½” thickness of the rim, and down the inside wall 10”. This crack severed over 50% of the cross sectional area of the gear rim. The cracking in the roots of the two adjacent teeth was similar to the worst crack but to a lesser degree. The total cracking at these three locations was found to be approximately 58”.

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This Bucyrus Dragline Cracked a Rack Gear Segment

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Three Crack Locations – METALOCKS Being Installed

Crack Locations

METALOCKS

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Cross Section of Typical CrackRoot of Tooth

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Close Up of Longest Crack

Crack Location

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Close Up of Finished Repairs

Crack Locations

METALOCKS

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Reinforcement Brackets Being Installed

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View of Finished Reinforcements

Crack Locations

Reinforcement

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Repair of Cracked Pintel on Large Dragline

The Pintel of this dragline was found to be cracked circumferentially around a line immediately above the floor of the pan of the dragline. The cracking extended approximately 1/3rd around the circumference of the Pintel and completely thru the 7” wall thickness.

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This Dragline had a cracked Pintel

Large TruckLarge Dragline

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Access Hole to the Pintel Area

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View Thru Access Hole to the Dragline Base

Sliding Base

Rotating Floor White Tennis Shoes ??

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Repaired Pintel Cracking – Right Side

MASTERLOCKS

METALOCKS

Pintel

Stationary Base

Rotating Floor

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Repaired Pintel Cracking – Middle Area

MASTERLOCKS

METALOCKS

Pintel

Stationary Base

Rotating Floor

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Repaired Pintel Cracking – Left Side

MASTERLOCKS

METALOCKS

Pintel

Stationary Base

Rotating Floor

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Repair of Trunnion/Head on a Ball Mill

The Trunnion and Head on this Mill was a one piece casting. It became badly eroded when product leaked behind the trunnion liner and raced around the I.D. until it eroded nearly thru the 5” thickness of the trunnion wall. When the remaining thickness reached ¾”, the trunnion broke completely off. Our repair consisted of converting the one piece trunnion/head design to a two piece configuration. The head was machined to receive the new trunnion which was attached with METALOCK and METALACE and with a series of high strength custom bolts.

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Broken off Trunnion

Broken Off Trunnion

Mill Head

Trunnion Stub

Remaining Thickness

Heavily Eroded Area

Heavily Eroded Area

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Mill Head

Trunnion Stub

Remaining Thickness

Heavily Eroded Area

Close up of Head Where Trunnion Broke off

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Mill Head

New TrunnionRough Machined

METALOCK& METALACE

New Trunnion Positioned on Head

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METALOCK and METALACE Installation

Mill Head

New TrunnionRough Machined

METALOCKS Being Installed

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Close Up of METALOCK Installation

Mill Head

New TrunnionRough Machined

METALOCKS Being Installed

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Bolting Installed in Inner Flange

I.D. of New Trunnion

Inward Flange of New Trunnion

High Strength BoltsInstalled from Mill Head Side

Mill Head

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Mill Head

New TrunnionRough Machined

METALOCK& METALACE

New Trunnion Installation Nearly Complete

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Finish Machining of Trunnion After Installation

Trunnion Machining

Mill Head

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Completed Head/Trunnion Ready for Installation on the Mill

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New Trunnion

Maximum Stress Area

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Inside View of Stress Analysis Model

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New Trunnion

Mill Head

Bolts Installed Here

METALOCKS and METALACE Installed Here

Cross Section of New Trunnion/Head Design

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New Trunnion

Mill Head

Bolts Installed Here

METALOCKS and METALACE Installed Here

Close Up of Cross Section of New Trunnion/Head Design

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The Trunnion on this Ball Mill became severely eroded by product racing around the I.D. of the Trunnion in the same manner as the the Mill Presented above. In this case the trunnion was cracked but was not broken off. Due to time constraints the Customer chose a temporary repair option.

Repair of Ball Mill Trunnion at a Gold Mine

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Mill Head

Trunnion

Eroded Area

Cracking

Cross Section of Head/Trunnion

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Cracking

Cross Section of Trunnion Area

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Cracking

O.D. of the Trunnion Journal Cracked Area

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METALOCKS

Heavily Eroded Surface

METALACE

I.D. Surface ShowingThe Cracked Area

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Reinforcing Sleeve

Nordback Epoxy FillerPumped in after SleeveHad been Installed.

Repaired Crack Location

Temporary Repair Option with a Reinforcing Sleeve Insert

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New Trunnion

Head Machined to Receive New Trunnion

Optional Permanent Trunnion Replacement

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High Spots being ground to clear O.D. of Sleeve Insert

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Sleeve Fitted in Place

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Holes being Drilled from Inside Head And Tapped into the New Sleeve.

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Angle Bolts Installed

Angled Holes being DrilledThru the Sleeve and into Head

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Installation of the NewReinforcing Sleeve isComplete and the MillIs Ready for the LinerTo be installed and theMill Returned to Service.

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Cracked Gear Case on Coal Pulverizer

The Gear Cases on Combustion Engineering Raymond Type Bowl Mills (RP3 Models) with bowl sizes of 80” or more are highly subject to cracking. These cracks occur At 2 specific locations as described in the following slides. The cracking in these gear cases can be readily repaired during a normal overhaul outage with the techniques shown below.

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Input Side of the Mill Gear Case

Cracked Area

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Outboard Side on the Mill Gear Case

Cracked Area

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Cross Section of the Bowl Mill Case

Cracked AreaCracked Area

Input EndOutboard End

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View of Inside of the Mill Gear Case

Input Side Outboard Side

Cracking

Cracking

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View of Outboard Side Cracking

Cracking

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Layout of MASTERLOCKS on Outboard Side

MASTERLOCKSCracking

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MASTERLOCKS Being Excavated

MASTERLOCKS

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MASTERLOCK on the Top Surface – Outboard Side

MASTERLOCK

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Finished Repairs on the Outboard Side

MASTERLOCKS

METALOCKS

Stud Hole Bushing

Stop Drill Stud

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Cracking on the Outside Surface – Outboard Side

Cracking

Locks Installed by Others

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MASTELOCK Layout on Outside of Outboard Side

MASTERLOCKS

Crack End

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MASTERLOCKS Being Installed on Outside

MASTERLOCKS

METALOCKS

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Cracking on the Input Side

Cracking

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MASTERLOCK Layout on the Input Side

MASTERLOCK Layout

METALOCK Positions

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MASTERLOCK Being Installed on Input Side

MASTERLOCK

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Finished Repair on Input Side

MASTERLOCK

Stud Hole Bushing

METALOCKS

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Stress Analysis of Cracked Walking Eccentric on Large Dragline

This is an example of how powerful computer modeling is for evaluating design and cracking problems. We were asked to study the cracking problem in the walking eccentrics that are found on many large draglines. Part of this study was to develop a computer finite element stress model of a typical eccentric. To properly simulate the loading on the eccentric we had to include in the model the whole walking mechanism. The following slides show this model and the results that can be obtained with this powerful analysis tool.

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Computer Stress Model of Walking Mechanism

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Foot Down and Dragline Being Lifted

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Foot Down and Dragline Moving to Left

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Close Up of the Holes in the Eccentric

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Maximum Stress at First Contact with Ground

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Close Up of the Eccentric

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Close Up of the Holes Where the Cracking Occurs

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Repair Techniques and Components

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MASTERLOCK

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ANGLELOCK

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PRELOADED MASTERLOCK

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KEYLOCK

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TIELOCK

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ECRS/METALOCK

Any Crack

Any Where

Any Time