Liebherr has expanded its portfolio of piling and drilling machines for deep foundation applications with the LB 30 “unplugged” drilling rig. The battery-powered drive concept offers the same performance as the conventional diesel version and with the advantage of zero emissions.
While the diesel LB 30 is powered by a Liebherr D936 StageV/Tier4f engine rated at 320 kW (429 hp) @1,700 rpm, the battery-electric unit includes an electric drive motor rated at 390 kW, with energy storage in high-performance Li-Ion NMC (nickel manganese cobalt) batteries. Mains voltage is 400 Vac.
During operation the drilling rig can be connected to a conventional electric supply or powered by a battery without a cable, therefore “unplugged.” The new battery-operated unplugged units are identical regarding application possibilities, weight and transport.
The drilling rig delivers the necessary capacity for all common deep foundation operations, such as Kelly drilling (a standard procedure for installing large-diameter piles), double rotary drilling, full displacement drilling, continuous flight auger drilling, soil mixing and applications with a vibrator or hydraulic hammer. The machines can be deployed for drilling diameters of up to 11.2 ft (3.4 m). Both electric and diesel LB 30s can be lowered for transport and are designed for fast set-up at the jobsite. The robust undercarriage provides excellent stability.
For battery operation, the charging cable only needs to be unplugged and, for unlimited operation, reconnected to the construction site power supply. The battery is designed for a working time of four hours in normal operations. Whether in battery or plugged-in operation, drilling performance remains unchanged.
The hydraulics-intensive machine includes double axial-displacement pumps (2 × 71 gpm) in an open-loop system for attachments and a 34 gpm pump for kinematics. The set-up allows all operations to run simultaneously. Fixed axial-piston hydraulic motors handle the travel drive and swing functions. In addition to drilling, travel and swing operations, other hydraulic functions include powering lift cylinders and winches, chain tensioning on the track crawlers, and hydraulic release of travel and swing brakes. Hydraulic tank capacity is 158 gal; there is electronic monitoring of all filters; and synthetic, environmentally friendly oil is recommended.
Maximum working pressure is 385 bar (5,584 psi) and maximum drilling torque is nearly 300,000 ft lbf.