3 Alice Street
BASSENDEAN (Perth) 6054, Western Australia
Ph: +61 8 9279 5522 Fax: +61 8 9279 9386

Mining Equipment > Dragline - Replacement Parts

UDD MECHANICAL CONVERSIONS

Hofmann Engineering Pty Ltd completely designed, manufactured and installed the mechanical drive for the UDD (Universal Dig & Dump) dragline. Our concept provided a free-floating, alignment-free, shaft-mounted, modular gearbox that bolts to the side of the rope drum. This gearbox contains HofCarb carburised and precision ground gearing with a filtered oil recirculation system. Being shaft-mounted and modular enables this gearbox to be pre-test run and changed out in under one shift without requiring any re-alignment.

SWING RACK ASSEMBLIES

  • Alloy Steel Forged Rack Rims Q&T to 330BHN Combined with fabricated construction.
  • High performance racks with a unique heat treatment procedure that increases the hardness to 450BHN.
  • Swing Pinions are full contour induction
    hardened.

INPUT MOTOR PINIONS

  • Double Helical Hard Cut Narrow Gap. Case Carburised to 60-62HRC & finished to AGMA 12 quality.
  • Single helical case hardened. These are fitted with eccentric cartridges and spherical roller bearings.This assembly fits straight into the Bucyrus hoist or drag gear case bore. The eccentric cartridges enable simple mesh adjustment without having to re-bore the gear case.
  • Quench & tempered to 360 BHN and cut to AGMA 10 quality as per OEM design.
  • Carb Bearing Alignment Technology with Eccentric Cartridges can also be used on Bucyrus machines to give over a 200% improvement in bearing life.
DRUM GEARS
  • New Forge Fabricated Gears 330 to 360BHN precision cut to AGMA 10.
  • Mechanically Re Rimmed Gears. Replace only the gear teeth and save time and money.
  • Re Rimmed Gears. Remove old rim and weld new rim to hub with submerged arc full penetration weld.
INTERMEDIATE PINIONS
  • Double helical zero-gap carburised to 60 HRC and precision ground to AGMA 12 quality.
  • Conventional thru hardened to 360BHN and cut to AGMA 10 quality.
  • Complete assemblies can be supplied with bearings fitted.
SELF ALIGNING PINONS
Hofmann Engineering makes a complete range of self-aligning pinions for dragline gearing. These provide 100% gear mesh contact in all modes of operation and overcomes the run out of the drum gear and gear case deflections.
  • Intermediate double helical zero-gap case hardened self-aligning pinions.
RACKS, RAILS, ROLLERS
  • Swing Racks Forged fabricated design with High Alloy steel forged segment. Through hardened or induction hardened.
  • Upper and Lower Rails Forged HofAlloy plate through hardened 340-360BHN and precision CNC machined.
  • Rollers Forged through hardened 410-415BHN and precision CNC machined.
SWING & PROPEL SHAFTS
  • New shafts of high alloy forged steel
  • Repair Worn out splines and bearing Journals to as-new condition using a technically advanced, individual weld & Heat Treatment procedure.
SWING GEARING
  • New Forge Fabricated Gears 330 to 360BHN precision cut to AGMA 10.
  • Induction hardened to 56HRC and precision ground to AGMA 12 quality.
  • Re Rimmed Gears. Remove old rim and weld new rim to hub with submerged arc full penetration welding.
CENTRE PINTLE
  • Designed using FEA modeling to reduce magnitude of stress and reduce stress concentrations.
  • New forged steel construction to overcome cast steel cracking problems.
  • Forged steel centre pintle used on P&H 9020 in operation since 2002.
SHEAVES
  • New cast steel full contour induction hardened to 55HRC for a case depth of 6mm.
  • Repaired sheaves by full penetration submerge arc welding the worn groove and then induction hardening.
SWING GEARING
  • New Forge Fabricated Gears 330 to 360BHN precision cut to AGMA 10.
  • Induction hardened to 56HRC and precision ground to AGMA 12 quality.
  • Re Rimmed Gears. Remove old rim and weld new rim to hub with submerged arc full penetration welding.
PRODUCT IMPROVEMENTS
  • Co-Ordinate measuring machine is used to precision measure components.
  • Metallurgical laboratory to analyse chemistry, hardness & microstructure.
  • Engineering office with full CAD,CAM FEA and gear design software.
MARION 8050/8200 HOIST ARRANGEMENT
  • Modular design allows quick and easy change out.
  • Rigid construction reduces distortion and gear misalignment.
  • Interchangeability between gearboxes and gearing.
  • Self-aligning technology maintains 100% contact during floor deflection.
GEARBOX MODULE
  • Maintenance and testing of gearbox can be done in a clean workshop rather than inside the dragline.
  • Installation requires less skill and accuracy with the self aligning pinion.
SHAFT MOUNTED GEARBOX
  • Modular design allows quick and easy change out in one shift.
  • Rigid construction reduces distortion and gear misalignment.
  • Free floating isolated from dragline floor distortion.
  • Alignment free gearbox bolts directly to the hoist drum.
  • Gearing forged, HofCarb carburised to 60-62HRc, precision ground to AGMA 12.
  • Spherical roller bearings increase life.
  • Oil lubrication ISO 320cst supplied to gear meshes and bearings.
INTERMEDIATE ASSEMBLY
  • Intermediate gear forge fabricated, staggered tooth, double helical, through hardened 330 to 360BHN, precision cut to AGMA 10 quality.
  • Intermediate shaft forged, spline coupling carburised to 60-62HRc, precision cut to AGMA 12 quality.
  • CARB bearings increase bearing life by up to 200%.
SELF-ALIGNING PINION
  • Self-aligning gearing technology maintains 100% contact in operation.
  • Double helical zero-gap 19� face width, carburised to 60-62HRc and precision ground to AGMA 12 quality.
  • Spherical bearings carburised to 60-62HRc and lapped for 100% contact, oil lubricated.
CARB BEARINGS
  • Axial displacement tolerated.
  • Angular misalignment tolerated.
  • Combined axial displacement and angular misalignment tolerated.
  • Bearing housing distortion tolerated.
  • Oil lubricated for increased bearing life.
SWING RACKS
  • Forge fabricated construction with High Alloy steel forged segment.
  • Induction hardened full contour induction hardened to 45-49HRc 8mm thick case.
  • Impact resistant core hardness of 280-310BHN.
SWING PINIONS
  • Forged High Alloy steel precision ground to AGMA12.
  • Induction Hardened full contour induction hardened to 54-58HRc 8mm thick case.
  • Impact Resistant Core hardness of 280-310BHN.
MECHANICAL RE-RIM GEAR
  • Spider Gear teeth removed from OEM Cast bullgear to form Bullgear Spider.
  • New Forged Gear Rims 19� face width narrow gap, 330-360BHN, precision cut to AGMA 10.
  • Mechanically Fastened rim to spider.
  • Overlapping Split Lines increasing strength.

Production

1
ROPE DRUM DESIGN
  • Finite element analysis has been conducted in order to eliminate the inherent OEM rope drum internal stiffener cracking problem.
  • Hofmann Engineering Pty Ltd design removes all internal lateral stiffeners and increases the drum shell forging thickness to reduce stress.
2
ROPE DRUM MATERIAL
  • Hofalloy2 Forged Plate has been specifically formulated by Hofmann Engineering Pty Ltd to accommodate industry requirements. The result is a Quench & Tempered high alloy steel suitable for induction hardening, machining and fabricating. Stocked quantities are maintained in order to reduce lead-times.
3
ROPE DRUM ROLLING
  • The stocked Hofalloy forged plate rolled into a perfect cylinder using Hofmann Engineering Pty Ltd�s, 5000 ton Vertical Roll Press.
  • The above drum is 150mm thick 1900mm long and with an OD of 2947mm, in its rolling condition it is approx. 300 BHN.
4
ROPE DRUM MACHINING
  • All Rope Drums are fully machined in house from the initial fabrication preparations right through to the cutting of the rope grooves, turning of the flanges and drill and tapping of the holes. This ensures that complete control of the project is maintained and the highest standards of quality are guaranteed.
5
INDUCTION HARDENING
  • New Forge Steel drums fully fabricated using full penetration welds and then full contour induction hardened to 55 HRC for a case depth of 6mm.
  • Worn Drums. All cracks removed before building up with 30mm of submerged arc welds and then induction hardening.
6
ROPE DRUM CLAMPS
  • Unique design developed by Hofmann Engineering Pty Ltd.
  • Clamp is integrated into the rope drum centre flange.
  • Precision machined.
  • Case hardened.
  • Optimised for weight.
  • Greater clamping force.
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