With more hydraulic excavators being deployed at mining operations, interest grows in new service systems and GET.
With more than 30 units operating in four countries, the Liebherr R 9400 hydraulic excavators (the latest model in the Liebherr range of mining excavators) achieves new peak values in terms of tons per hour in its service weight category. The 350-metric-ton (mt) R 9400 can be used to load 130- to 150-mt haul trucks. The unit can be equipped in either a backhoe or face shovel configuration with a 22-m³ bucket. Either electric-motor or diesel-engine drive can be chosen, making this machine ideally versatile for a wide range of applications.
At the design stage, the R 9400’s overall efficiency was maximized by increasing the efficiency of each individual sub-system. In addition, routine maintenance for the machine is planned systematically with no unnecessary loss of time, so that the high availability needed for mining work is assured. The production-tailored attachment kinematics, combined with a mining-optimized bucket shape, ensure high digging and breakout forces.
The R 9400’s three-piece heavy-duty undercarriage was constructed to be fatigue resistant and that design also provides efficient superstructure weight distribution. Various track pad widths are available to match ground contact pressure to local requirements.
Optimizing electrical, mechanical and hydraulic power distribution, the Litronic Plus System allows for easy control even when simultaneous movements are required. The hydraulic cylinders are fitted with the patented Liebherr Electronic Damping System, which provides controlled end-cushioning for fast and smooth machine motions.
The R 9400 is powered by a Cummins QSK50 diesel engine that complies with the EPA Tier 2 exhaust emission limits and has a rated output of 1,250 kW (1,675 hp). The electric drive version is an efficient alternative if machines are required to operate in arctic conditions or if the mine has its own electric power supply available.
The well-equipped cab of the R 9400 is mounted on silent blocks. They reduce vibrations and the level of noise reaching the operator. The cab is of robust steel construction with low stress levels and safety glass windows; it protects the occupant against falling objects in accordance with the current safety standards. For extra safety, emergency stop switches are positioned at ground level, in the cab and in the pump and engine compartments for easy access. All routine maintenance points on the R 9400 are easily accessible: the service drop down flap makes it easy to check operating fluid levels and keeps maintenance times short.
Jacking System for Slewing Ring Maintenance and Replacement
Liebherr also supplies tailor-made service tools for maintenance work on mining excavators and the replacement of hydraulic pumps and cylinders, travel drives or track pads. Optimal working conditions are assured despite the size of these components. The service tools include a pin puller, a hydraulic pump lifting tool, a monitoring system for crawler tracks and their components, and a jacking system.
The new jacking system developed by Liebherr is a straightforward, cost-efficient method of raising the mining excavator’s superstructure for necessary maintenance or replacement of the slewing ring. This jacking-up principle is a safe, efficient alternative to complex lifting work with a crane.
The system has four synchronized hydraulic supports with an integral power stage and mechanical locking, the lifting frame, and a roller unit on which the working equipment is supported. These elements work smoothly together and lift the load safely with optimal weight distribution.
As soon as the cylinder pins have been removed, the lifting frame has been installed and the bolts securing the slewing ring have been unscrewed, jacking up can be carried out by one person. In only 15 minutes the superstructure reaches the maximum height needed to run the undercarriage out from beneath it. An ergonomically designed wireless remote control permits unrestricted movement, and an integral LCD display enables the user to monitor the system while the superstructure is being lifted.
Mining Z System for Buckets
To maximize bucket fill factor and improve cycle time, Liebherr has developed an extensive range of teeth and wear protection elements or ground-engaging tools (GET) to perfectly fit Liebherr backhoe and face shovel buckets. The new GET series designed for use with Liebherr mining excavators enables easy material penetration while extending bucket steel structure lifetime. The innovative bucket lip and side wall protection from a shield around the bucket areas protects against material abrasion. Edges and adaptors are shaped to protect the welding of the blade. This has a positive effect on the cost per ton of excavated material.
The new Liebherr Mining Z system, for instance, consists of a tooth adapter welded on the lip, a tooth, a wear cap, a lip shroud and a unique securing pin with a locking arrangement. The Z system is suitable for extraction work of all kinds.
The CL, CR and P profiles are available in five sizes for a broad range of applications. These sizes cover light (GP), standard/medium hardness (HD) and extra-hard (XHD) terrains. The truly hammerless locking system simplifies tooth and wing shrouds replacement with a single tool. By turning the tool clockwise through 90˚, the retaining pin, tooth, and adapter can be rapidly released or locked into position. The Liebherr GET are compatible with Liebherr mining backhoe and face shovel excavators up to the R 9400.