04/13/2021 Like a racing car, only a little bigger
Saving weight helps sports and racing cars to achieve maximum power and performance.It might almost sound strange to talk about this with regard to snow groomers, track-driven commercial vehicles and bulldozers. Yet, there are still similarities. The Liebherr LPI gearbox series make a clear contribution to it.
One of the most important key figures in motorsports is power density. The ratio between weight and torque is decisive for the development of power and speed. It is for good reason that in motorsports, the aim is to save every single kilogramme, ultimately resulting in a lightweight construction. In tracked vehicles, this might look a bit strange at first glance. Here, too, the saving of kilos plays a crucial role in certain applications.
The Liebherr gearboxes from the new LPI series make a clear contribution to weight saving. Completely redesigned, they feature new materials, a significantly more compact design and a significantly lighter final weight. The result is a considerably increased torque density.
For design engineers, this means that they can often install an entire gearbox size smaller than the conventional travel drives in their crawler undercarriages. This is possible thanks to this increase in the required output torque of the new gearboxes. A drive pair - two gearboxes in only one size smaller - helps to save up to 500 kg in weight even on a medium-sized crawler. This already amounts to a weight saving of half a ton. This creates new, interesting aspects, especially when it comes to developing tracked all-terrain vehicles or snow groomers. These machines should have relatively agile driving characteristics with the lowest possible fuel consumption, which is made possible by saving weight and installation space. Such a reduction also helps, if the payload is to be increased and the permissible total weight must not be exceeded.
Seven basic gearboxes with a transmission range between 15 and 750 cover a torque array from 20,000 NM to 380,000 NM. They are available with two, three or four planetary stages. Robustly designed, they incorporate decades of experience from the heavy-duty travel drives of Liebherr's own mining machines.
A powertrain consisting of electric or hydraulic motors with the lightweight LPI travel drives thus opens up completely new possibilities. Therefore, even heavy machines for mobile applications with a payload of several hundred tons can reach their top speeds even more easily. These may not be particularly high, but in terms of payload at maximum load, they are a remarkable result. "In principle, it is similar to motorsports. Like in a racing car, weight reduction plays a very important role in chain-driven applications, especially when mobility is one of the main requirements. It's just all a bit bigger," says Enrico Menozzi, Head of Sales Europe at Liebherr-Components AG, with a wink.
Another special advantage of the LPI gearbox series is its great flexibility. In addition to electric drives, they can also be used as original equipment or as a retrofit for hydraulic motors. In combination with hydraulic motors, such weight saving leads to a significantly lower fuel consumption and less harmful emissions for the environment.Read more