The electric crawler excavator Liebherr R 976-E comes at the same time as R 980 SME-E, it is a successor of ER 974 B designed for mines and quarries. The newest electric excavators developed by the Liebherr-France SAS company in Colmar, France, are not just an adaptation of excavators with combustion motors. The Liebherr company has devised and realized a complex development and electrification for this machine.
The new excavators are distinguished by:
These 90 or 100 tonnes excavators are, thanks to their massive design, durable in the most extreme conditions. They are shipped in a backhoe bucket and a front shovel version. Low noise level, optimal availability, and no release of CO2 and other greenhouse gases emissions are typical for them.
Time-tested electric system
During last several decades, the Liebherr company has, without doubt, proven the quality and reliability of its electric technologies on several successful type series of mining, pontoon, and industrial machines.
The electric system of the new crawler excavator Liebherr R 976-E, with the power of 400 kW, is powered by a cable with voltage of 6000 V. The cable input can be found in the centre of the undercarriage or, custom-ordered, also on the sides. There is also the option for cable cylinder. The electric power supply is 6000 V / 50 Hz provided by a high-voltage revolving transformer. There is a transformer cabinet on the body of the excavator (HV / LV), and low-voltage electric cabinet, and control of the on-board voltage 690 V, 230 V, and 24 V.
Advantages of integrated technologies
The integrated technology of R 976-E and R 980 SME-E models has many advantages. An excavator with electric motor has a longer life-span thanks to its constant speed of the engine during any workload. The high performance in low revs, even when more functions are running at the same time, brings excellent effectiveness of the machine. Low-voltage asynchronous electric motor installed on the R 976-E excavator runs a hydraulic system. The motor is equipped with protection against over-heating of bearings and winding. It is integrated on the frame with a strengthened flange and it enables a safe and light start of the engine. Two robust electric distribution boards are made from a special welded construction proportioned for extreme working conditions. Lockable water-proof doors (IP 65) are set with a safety switch and the function of emergency switch-off.
Reliability and robustness
The electric excavators Liebherr stand out on the market in comparison with other machines by its high performance. They have a robust design which meet the requirements for mining machines. The tests of reliability were done in extreme conditions. The Liebherr company guarantees, as a part of their sustainable and ecological programme, that there are no emissions of dangerous gases for the environment. The concept and production of all the electrification was done by the Liebherr-France SAA company taking into consideration a guaranteed quality for the users.
Comfort of the working environment
The operators of excavators R 976-E and R 980 SME-E have a guaranteed complete comfort and safety. A spacious cab with automatic air-conditioning and heating, and a 270° camera system with a front and roof windows with armoured glass from the outer side, confirm it to be true. The serial design has a cab equipped with a whole series of controlling functions with a large 9″ display.
Ecology and economy
The maintenance is easy and low running costs ensure higher economy in comparison with excavators with combustion motors. Another comfort lies in the extremely low noise production of models R 976-E and R 980 SME-E. The excavators R 976-E a R 980 SME-E comply with the requirements of ecological operations of machines thanks to their robustness, reliability, and economy.
Source: Lomy a těžba