8750
8750 Dragline
DESCRIPTION
Offering the highest levels of overburden removal productivity at the lowest total cost per tonne (ton), the 8750 is the flagship model of the Cat dragline product line. The first dragline of any kind to be successfully equipped with AC IGBT drive systems, we developed this superior technology for the sole purpose of making your workday more productive, predictable, and most importantly, safe.Motion Regulator Control (MRC)
- Sturdy, mine-grade cabinet mounted on a self supporting steel structure encloses all power and control electronics.
- AFEs, rather than rectifiers, convert AC to DC power.
- Fuseless IGBT modules in AFEs and inverter.
- Onboard maintenance computer is easy to troubleshoot, quickly identifies faults, and provides instructions to resolve issues.
- Major control and power electrics are derived from the transportation sector, allowing for high temperature ratings, shock and vibration ruggedness, and longevity of component availability.
- IP 54 enclosure – liquid cooled, heat transferred out of machinery house.
- Cabinets allow optimized cable routing.
- Cable internals organized to allow efficient access to internal components.
Harmonics
- Staggered Active Front Ends (AFEs) naturally cancel harmonics without filters, which makes the dragline very robust and independent of mine network configuration.
- Provides better Total Harmonic Distortion (THD) than required by IEEE 519.
High Voltage Switchgear
- Rated at 24 kV.
- Provides programmable protection and control for Auxiliary Power Transformer (APT) and Drive Power Transformer (DPT).
- Internal and key interlocking provides for safe operation.
AC Main Motion Drive Motors
- Simple, AC squirrel-cage induction motors power swing, hoist, drag and propel motions.
- Built in speed sensor that is replaceable without removal of motor from service.
Comfort Infused, State-of-the-art Operator's Cab and Station
Providing more comfort, added safety, and greater reliability, our newly designed state-of-the-art operator's cab will help you produce more. The product of a multi-year collaboration with mining companies from across the globe, our Design Engineers, armed with insights into the aspects most desired by you, have designed what we believe to be the most comfortable and productivity-enhancing operator's cab in the industry.
- Improved operator performance – Reduced cognitive fatigue and enhanced productivity via the intuitive and visually aesthetic display screens. – Effortless operation and improved control response resulting from new Hall Effect joysticks (patent pending), with custom-designed ergonomic handles and “finger touch control” spring tension.
- Enhanced safety – Rear ingress/egress door with no step floor prevents trip hazard, particularly in cases of emergency where rapid exit from the cab is necessary. – Superior visibility with full operator-to-boom point line of sight. – Maximum operator situational awareness via external camera system with direct feed to overhead monitors in cab. – Enhanced safety during operator training with additional emergency stop button within reach of trainer seat.
Swing Machinery
- Highly reliable swing planetary transmission and output pinion.
- Interchangeable parts across all swing drives.
- Potential for machine to operate with removal of one swing unit (typical maintenance).
- Cooler/filtration unit plumbed to each planetary gearcase. Controlled and monitored via dragline Programmable Logic Controller (PLC).
Hoist/Drag Machinery
- Parallel shaft gearcases, with eccentric bearing cartridges for optimal gear alignment.
- Gearing, bearings, drums, etc are interchangeable between hoist and drag motions.
- Splash lubricated gearcases with optional filtration available.
- Leak proof inspection hatches for inspection of all gear mesh.
- Drums mounted on self aligning, anti-friction bearings.
- Motors coupled to input pinions with grid couplings to reduce impact loads.
Propel Machinery
- Heavy duty eccentric cam, driven by bull gear and parallel shaft gearbox.
- Eccentric bushing continuously monitored via RTD's. PLC will alarm and shut down machine if permissible temperatures are exceeded.
- Each side independently driven, but electrically synchronized, and monitored via dragline PLC.
- Shoe incorporates ball swivel mounting to accommodate variable ground conditions.
- Ability to propel machine up and down up to 10% grade and transverse across 5% grade.
Rugged Structures Designed and Fabricated to Withstand Your Extreme Mining Conditions
To extend service life and ultimately reduce your maintenance cost, all major dragline structures are designed for durability and dependability. Extended performance in the harsh mining conditions you face daily is accomplished through selection of high-strength steels, and rugged castings, joined and thermally stress-relieved weldments to create a reliable shell capable of the most productive surface extraction machine in the industry.
- Boom and Tri-structures are manufactured using cold-weather, impact-resistant, high-strength steel with select welds of full penetration, profiled and ground type.
- All structural welds undergo visual inspection, with critical welds also receiving MT, UT or X-ray inspection.
- For reduced susceptibility to cracking, large furnaces are used to stress-relieve entire critical weldments.
- Simplifying field inspections, interiors of finished structures are painted white.
Base Frame Assembly
- Grid-Radial design to optimize load and access.
- Forged integral center pintle.
- Stress relieved “T-section” roller path sub-weldment.
- Thick bottom plate, with abrasion resistant steel wear plates and anti-skid cleats.
Roller Circle, Rails and Racks (Gear Segment)
- Large diameter machined crowned rollers.
- Third rail eliminates flanged rollers allowing addition of more rollers extending service life significantly.
- Bias cut rail ends for smooth roller transition.
- Forged/fabricated rack segments, stress relieved weldment, quenched and tempered teeth.
Revolving Frame Assembly
- Deep, rectangular frame structure, running full length of assembly.
- Integrated thick rail pad circumferential diaphragm sub-weldment, and UT tested.
- Thick integrated plates for support of main machinery.
- Penetrations reinforced with through thickness plates as determined per FEA.
Fairlead Assembly
- Over-under fairlead provides constant rope contact with sheaves.
- Sheaves interchangeable with boom and tri-structure.
- Shimless fairlead adjustment system for lower swivel.
- Rubber composite “donut” between swivels to dampen dynamics.
Tri-structure Assembly
- Tri-structure design reduces front end weight and enables optimization with boom configurations, increasing allowable load and reach.
- Simplified wide flange beam construction, with high impact strength steel.
- Less maintenance points compared to A-frame/Mast assembly.
- Crack detection system for back legs and tri-structure head assembly, monitored by the PLC to provide a warning indicator.
Boom Assembly
- Rectangular, deep cross section geometry, constructed of high strength wide flange beams.
- Pre-stretched galvanized main support ropes with equalizers. Kevlar intermediate boom support ropes.
- Pressurized apex lacings, monitored through PLC.
- Boom point sheave assembly to align to bucket.
Bucket Assembly
- Bucket capacity and style application dependent.
- Final capacity takes into account ground mass per cubic meter, soil characteristics, abrasion, and digging style.
- Bucket capabilities range from 76-116 m3 (100-152 yd3).
- Rigging configuration is twin dump.
- Custom wear packages designed to suit a variety of soil conditions.
- Three different bucket styles available, HPS, Conventional, and Fabricated.
Dynavane Assembly
- Modular Dynavane assemblies decrease roof weight, easier to maintain and install.
Helping You Enhance Safety and Productivity through Technology
Aimed at enhancing the productivity and profitability of your dragline, we currently offer a combination of Cat MineStar System offerings and Cat dragline technology solutions.
Cat MineStar System
Helping you achieve your goals for enhanced mine site safety, improved efficiency, reduced operating costs, and greater profitability, the Cat MineStar System provides the most comprehensive suite of mining technology products in the industry. It consists of a number of configurable capability sets – Fleet, Terrain, Detect, Health, and Command – that allow you to scale the system to your mine site needs. Cat MineStar System helps you manage everything from material tracking to sophisticated real-time fleet management, machine health systems, autonomous equipment, and more.
The Cat 8750 dragline is currently able to utilize two of the Cat MineStar System capability sets:
- Health – Health delivers critical event-based machine condition and operating data for your entire fleet. It includes comprehensive equipment health and asset monitoring capabilities, with a wide range of diagnostic, analytic and reporting tools.
- Terrain – Terrain enables high-precision management of drilling, dragline, grading and loading operations through the use of guidance technology. It increases machine productivity and provides you real-time feedback for improved efficiency.
Dragline Technology Solutions
Enhancement of productivity and efficiency is afforded through Cat dragline technology solutions. This facilitates real-time machine tracking, assignment and productivity monitoring, reducing mean time to repair (MTTR), a full package of diagnostic equipment is also available.
- AccessDirect – Enables factory experts to join the local maintenance team. – Prepares maintenance personnel to arrive on site ready to fix rather than analyze the problem. – Reduces MTTR and daily maintenance efforts. – Enhances local and remote diagnostic capabilities.
- Description of AccessDirect – Electrical interface system that facilitates remote access to machine's on board computer via internet. – Permits monitoring, adjustment, resetting, and modification of electrical parameters. – Arrives with software for PLC, software for drives resident, and one server per fleet. – Features high-speed data transfer.
Dragline Model Recommendations Grounded in Analysis and Collaboration
Protecting your investment and ensuring that you achieve your cost per ton targets, we have on-staff Application Engineers and a new dragline optimization process to help determine the dragline configuration optimally suited for your application.
Structures/Surfaces
- Sturdy handrail mounting clamps prevent vibration induced weld cracks.
- Non-skid material on roof and shoe walkway surfaces prevent falls.
- Serrated bar grating stairs, platforms and walkways facilitate safe movement around the machine.
Electrical Equipment
- Emergency stop system is hardwired dual string with safety relay.
- All operator interface controls are 24 volt.
- Arc Flash evaluation available.
- Single point of motion disable for mechanical maintenance of machine.
- Key interlocking prevents access to incoming High Voltage connection areas.
- Stored energy warning signs installed at appropriate locations reduce injuries.
Providing You a Unified Team Unlike Any Other in the Mining Industry
While the Caterpillar acquisition of Bucyrus is complete, we are still in the process of integrating the two companies. However, you can rest assured that both your Cat and Bucyrus products will continue to be supported and that there will be no disruption in the service you have come to expect from both organizations. We are committed to business as usual — with sales, parts fulfillment, technical support, and all other customer services continuing uninterrupted. For the time being, Caterpillar Global Mining will operate from two distinct distribution channels:
- Legacy Bucyrus products, including our draglines, will continue factory direct with support from former Bucyrus employees that are now part of Caterpillar's Global Mining Division.
- Traditional Cat products will continue through Cat dealers with support from Caterpillar's Global Mining Division.