At Bauma 2016, Liebherr will unveil its new entry into the 200 t excavator class: the R9200, built to complement the broad Liebherr mining product range. It will also launch its first crawler dozer in the 70 t category – the new PR776, which is designed for tough mining and quarry operations.
The new PR776 is powered by a Liebherr 12-cylinder diesel engine developing 565 kW. It has a maximum operating weight of 74 t and is equipped with blade capacities of 18 m³ or 22 m³ (U blade). The modern drive concept of the new PR776 “offers extremely efficient and safe operation to customers.” A new feature in this machine class is the infinitely variable hydrostatic travel drive, which is used for all crawler dozers from Liebherr.
Another advantage of the modern drive concept is the optimisation of pressure flow. Hydraulic servo pressure is based on-demand according to the task. If, for example, the full feed of pressure supply is not required when operating, this is automatically returned. The ECO function is standard for all Liebherr Generation 6 crawler dozers – including the new PR776. It allows operators to choose between high performance and maximum efficiency. “The ECO control system enables greater travel drive efficiency in light to medium operations, and also provides greater fuel savings.”
The proactive power control is another innovation of the 6th generation crawler tractors. Internal engine and external machine parameters are recorded, such as the current deflection of the joystick. If required, the engine power is automatically increased for a brief period based on the current requirement. As well as responding more rapidly, the machines offer a significant increase in performance potential and pulling power and a higher reverse speed.
The intelligent Liebherr engine management system combined with the Liebherr Power Efficiency System and the hydrostatic driveline allows Liebherr to master and optimise all equipment systems and processes to maintain constant engine speed, increase overall machine efficiency and reduce fuel consumption of the PR776. “Differentiating Liebherr’s travel drive concept from other drive concepts available on the market, with which the engine speed fluctuates sharply during operation. All of these measures lead to significantly lower fuel consumption than the industry standard with similar pushing performance.”
Another key advantage of hydrostatically powered crawlers when working in restricted spaces is the excellent manoeuvrability with continuous power to both tracks. With an optional GPS navigation system, the work progress and the surrounding area can be visualised. increasing machine productivity and minimising operator stress and strain. Pendulum-mounted guide wheels and track rollers ensure excellent chain traction and significantly reduce equipment vibration.
The R9200’s 12.5 m³ bucket is the biggest in its class, and offers sustainable performance while delivering peak fuel burn efficiency, even in the most challenging conditions. “This world-class mining excavator is designed to match mining trucks with payloads of up to 140 t.” The R9200 is available in backhoe and face shovel configuration and is fitted with the Liebherr advanced bucket and GET solution. With its standard bucket, the R9200 bucket solution “delivers superior digging performance and high fill factors, even in the most extreme mining conditions.”
The new excavator is powered by the Cummins QSK38 diesel engine that complies with US/EPA Tier 2 or 4i exhaust emission limits and has a rated output of 810 kW. “The cutting-edge cab of the R9200 provides the operator with a panoramic view of their operation, which leads to efficient truck loading and safe machine positioning.” The R9200 also integrates an advanced electronic piloting control system “which is both intuitive and versatile.”