Liebherr’s hydrostatic tech dozes in
Liviero Mining has taken delivery of the first unit of the Liebherr PR 776 in South Africa.
Powered by a 768hp Liebherr 12-cylinder engine, Liebherr’s new PR 776 has a maximum operating weight of 74t, making it an ideal mining and quarrying dozer.
The juggernaut features larger 8m³ semi-U blade or 22m³ U blade. Tendayi Kudumba, divisional manager of Earthmoving Technology at Liebherr Africa, saysthe first unit in southern Africa has already been delivered to Liviero Miningand is being pu through its paces at thecontract miner’s Vanggatfontein site in Mpumalanga, South Africa.
The machine’s competitive edge is said to be its hydrostatic travel drive. The same drive concept is already used on all Liebherr’s crawler tractors, but is said to be a first for a dozer in the 70t category.
In split dozing applications, the hydrostatically driven dozer automatically slows down as the blade loads up and gains momentum as the load sheds off. Because you don’t have to shift gears, there isn’t any slight loss of momentum that comes with the shift. It also offers the benefit of dynamic braking. One eases off the throttle and hydraulic pressure within the system will bring the machine to an immediate stop.
The system also ensures that the machine doesn’t roll backwards. The hydrostatically driven PR 776 only needs one foot for the deceleration pedal. Another big plus of the hydrostatic drive concept is the optimisation of pressure flow. The hydraulic servo pressure is based on-demand according to the task at hand. If, for example, the full feed of pressure is not required when operating, it is automatically returned, providing sound fuel savings in the process.
In addition, it offers the crawler tractor sound manoeuvrability with continuous power on both tracks.
Equipment Africa says: The principal benefit of a hydrostatic transmission on a dozer is the absence of gears, resulting in seamless operation, uninterrupted power flow and infinitely variable speed control. Liebherr has gone an extra mile by equipping a dozer in the 70t category with this concept, said to be a first in the industry.