Contents of Engineering & Mining Journal - FEB 2012

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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SUPPORT EQUIPMENT
high visibility of the working area as well as the blade and rear ripper. The dozer also features demand-controlled cooling, wear-free braking via the hydrostatic drive system and a long list of options. In a similar vein, a characteristic fea- ture of Liebherr's range of large wheel loaders is the optimized hydrostatic drive concept, based on two directly coupled hydraulic motors of different sizes, each with a separate clutch. Because at least one of the two motors is active when the wheel loader accelerates and deceler- ates, the loader can adjust to any working condition regardless of travel speed required and without the need for the operator to shift gears. With an operating weight of 69, 180 lb (31 mt) the L586 Litronic is the flag- ship of Liebherr's wheel loader line and is the largest wheel loader in the world with hydrostatic drive. The L586 displayed at Las Vegas had a 7.8 yd3 bucket with a v- pattern overflow plate and teeth. The exhibit model was also equipped with a rear collision guard, undercarriage protec- tion and twin LED work area lights at the front and rear. Other equipment included an audible warning signal when reversing and camera monitoring of the area behind the vehicle. The L586 is powered by a Liebherr six-cylinder, turbocharged diesel engine with a charge air intercooler, and develops 340 hp (250 kW). Volvo Construction Equipment does not have a dozer product line, but offers
a wide selection of wheel loaders, with the L350F at the top of the line's payload rating range. When introduced several years ago, Volvo CE reported that the new model provided an 18% increase in pro- ductivity and 46% better fuel economy over its predecessor, when tested in load and carry operations. The source of these improvements, said Volvo CE, resided in the combination of the L350F's new Tier 3/Stage IIIA Volvo engine, stronger hydraulics, an improved lift arm, a new transmission with lock-up and new axles. The L350F's Volvo D16E engine pro- duces most of its 532 hp (397 kW) and torque at low engine speeds, reducing the need for over-revving as well as pro- viding better fuel economy, reliability and low noise and emissions. The engine is mated to the latest transmission from Volvo—the HTE400—with automatic lockup in third and fourth gears. The transmission features automatic power shifting that offers a selection of shift programs to suit the application as well as operator work style. The system also can be activated to automatically down- shift to first gear, leaving the operator only having to select between forward and reverse gears.
Stopping power comes in the form of outboard-mounted wet disc brakes with oil cooling. Powered by a hydraulic dual circuit brake system, the parking brake automatically applies when the engine is switched off or if brake pressure too low.
Brake condition can be monitored by wear indicators on each hub and a brake test can be done from inside the cab. The load sensing hydraulics system on the L350F also were improved, with vari- able displacement pumps providing exact flow and pressure on demand. Bucket capacity for the L350F ranges from 8.1 to 16.6 yd3 (6.2 to 12.7 m3). Breakout force is rated at 106,290 lb-ft (472.8 kN). The L350F's lift arm features improved geometry that is claimed to provide good rollback angles as well as better attachment visibility. The loader also can be specified with boom options: the long boom gives additional dump height while a Boom Suspension System features heavy duty shock absorbers that reduce bucket spillage and allow faster, more comfortable, work cycles.
East Meets West in the Dozer Market
LiuGong Machinery Corp., Liuzhou, China, recently finalized an agreement to acquire Polish heavy equipment manu- facturer HSW (Huta Stalowa Wola) and its distribution subsidiary, Dressta Ltd. The transaction is LiuGong's first outright acquisition outside its domestic market. HSW manufactures bulldozers, load- ers and other crawler machines, and is one of only seven manufacturers world- wide producing a complete line of bull- dozers from 74 hp to 520 hp. The Polish government, which owned HSW, had agreed in principal to sell to LiuGong ear- lier this year with the signing of a prelim- inary enterprise acquisition agreement in Beijing, China.
Liebherr PR764 Litronic dozer. 66 E&MJ; • FEBRUARY 2012
The roots of HSW/Dressta earthmover technology can be traced back to 1972, when HSW entered into a licensing agree- ment with the U.S. agricultural equipment builder International Harvester, which had formed a Construction Equipment Division in the mid-1940s and was eager to expand market scope for its dozers and loaders into Eastern Block countries. International Harvester, however, encountered rough economic waters in the early 1980s and the construction division was acquired by Dresser Industries, which later struck a joint agreement with Komatsu for manu- facture of dozers, loaders and other equip- ment. Komatsu took control of the entity in the mid-1990s and carried on the long- standing arrangement with HSW, eventual- ly establishing Dressta as a joint venture— and brand name—for product develop-
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