Setting New Standards

Liebherr are set to launch their Generation 6 crawler excavators, promising new standards of performance, economy and reliability

Liebherr’s next-generation crawler excavators – the R 906 with an operating weight of 21.7–23.3 tonnes, the R 916 Litronic (23.7–26.4 tonnes) and the R 926 Litronic (25.7–27.1 tonnes) – will make their debuts at the 2009 Intermat exhibition.

Each machine is powered by a Stage IIIA/Tier 3-compliant four-cylinder engine, with the R 906, R 916 and R 926 developing 143hp, 157hp and 177hp, respectively.

The engine management and CANbus integration on the excavators helps keep engine speeds more constant, thus optimizing fuel consumption and making more efficient use of available power.

To meet the differing market requirements and customers’ demands, the new series will be available in either a ‘Classic’ or ‘Advanced’ version.

The former has been designed for general earthmoving tasks, while the latter, equipped with advanced Liebherr technology, is suitable for a variety of tasks, such as mining, embankment construction, demolition and industrial applications. 

One of the key features of the Generation 6 range is the ‘Positive Control’ hydraulic system, which is said to improve performance when excavator movements are superimposed, eg when grading and travelling either straight ahead or in a curve. In addition, the Advanced version benefits from higher operating pressure, which increases tractive effort and tearout/breakout power.

Another major feature of the new series, say Liebherr, is the enhanced performance and longer operating life of the undercarriage. The central section, for example, has been extended as far as the ends of the side members, distributing forces more effectively and prolonging the undercarriage’s working life.

The improved undercarriage also boasts a new travel gear design featuring a 23-tooth drive sprocket. Compared to the previous models, the maximum travel speed for the latest crawler excavators is 6.2km/h (17% higher), while tractive effort has increased by 12%.

The Generation 6 machines have also been developed to run more smoothly; the forged drive sprocket with integral dirt deflector, for example, helps maintain the excavator’s operational performance in difficult soil conditions. In addition, the new undercarriage is easier to service, as hydraulic hoses are clearly laid out for maintenance.

Liebherr claim their new crawler excavators perform operating cycles more rapidly than ever before, thanks to a new hydraulic system concept. Improving the superstructure slewing gear, slewing torque is now up to 50% greater and slewing speed more than 24% higher than on the previous models.  

Liebherr have also created a new structure for the slewing platform, which acts as a base for the standard ROPS cab, while the slewing ring now has a larger diameter that is said to distribute incoming forces more effectively, reduce stresses and ensure longer service life.

Externally, a toolbox has been incorporated into the steps behind the cab and the steel structure of the machines has been optimized in both weight and function to ensure the Generation 6 series can handle demanding operating loads. The latest excavators have breakout forces up to 20% higher and tearout forces up to 36% higher than on previous models.

Operators choosing the Advanced version of any of the three new models will benefit from a totally redesigned cab equipped with numerous features to improve comfort, convenience and safety.

The windscreen (which can be fully retracted), skylight and right-hand cab window are made of shatterproof two-layer safety glass and, to give the operator a larger field of view, the hydraulic hoses between the control valves and the base of the boom have been relocated.

The driver also benefits from a standard air-sprung seat with automatic weight compensation for maximum comfort, as well as control consoles that move around the seat to provide additional comfort and reduced operator fatigue. The cab is equipped with a touchscreen 7in high-resolution colour monitor, which is video-compatible and features numerous adjusting and monitoring functions. 

Advanced versions of the R 906, R 916 and R 926 incorporate what Liebherr say is a high-tech specification – their new excavator system technology known as ‘Positive Control Advanced’.  

The system features an intelligent user-management interface ensuring machine operations, such as hydraulic attachments and oil refill, can be carried out as quickly and smoothly as possible. Positive Control Advanced also acts as an on-board diagnostic system. 

Liebherr-Great Britain Ltd, Normandy Lane, Stratton Business Park, Biggleswade, Beds SG18 8QB; tel: (01767) 602100; fax: (01767) 602110