Debuting at Bauma via ZF's off-highway engineers will be a continuously variable transmission (CVT) for construction machinery, the ZF cPOWER, which it considers "the beginning of a new technological era in construction machinery," according to Hermann Beck, Vice President of Business Unit Construction Machinery Systems, Corporate Division Off-Road Driveline Technology and Axle Systems located at ZF Passau.
ZF says the cPOWER fully powersplit, CVT technology benefits from long-term experience gained in the agricultural machinery sector and offers significant consumption benefits and productivity increases for owners.
Not unaware of rising fuel prices and a raising awareness of CO2 emissions, ZF says the CVT will offer the market a more efficient drive system, while simultaneously dealing with new emissions guidelines (U.S. EPA and EU directives) that implicate technological restrictions and constraints with diesel engines that at times seem hardly achievable for continually strict future regulations.
High loads at low speeds in combination with high dynamics are the most prominent requirements for construction machinery. Those criteria are met, says ZF, by its CVT technology "in an up-to-now unthinkable degree of efficiency."
Making its case, it says that while searching for the ideal transmission concept it became clear that other technologies and mixed hydrostatic and powersplit concepts had considerable disadvantages and were only compromises with constraints in performance and efficiency.
The rising demands for fuel reduction and productivity increase require new technologies in construction machines, such as the CVT.
A trend toward lower engine speeds and the demand for engine stabilization by a constant speed concept are the future challenges on the construction machinery market. ZF believes the cPOWER meets both requirements.
In wheel loader applications, hydrostatic-powersplit transmissions ensure significant consumption benefits compared to hydrodynamic transmissions and purely hydrostatic concepts.
However, CVTs demonstrate their benefits in all ranges of the typical wheel loader operating cycle, i.e. during bucket filling, transporting, loading, etc.
During such duty loads, hydrostatic power is kept low, thus an optimal degree of efficiency can be achieved. In the start-up process, most of the output comes from the mechanical part of the transmission and even in very short loading cycles the utility of the CVT technology is noticeable in its reduced fuel consumption.
ZF says the application of an elaborate hydraulic transmission-control unit and transmission integrated onboard electronics optimally completes driving functions in reference to sensitivity and driving comfort and realizes an aligned power management.
Stressing that it is not new at this type of technology, ZF says the cPOWER transmission series deploys proven construction kit modules and benefits from its competence in transmission and vehicle system engineering.
Main features of the new ZF cPOWER include a continuously variable drive over an entire range; hydrostatic-mechanical powersplitting in all driving ranges, including the frequently used range up to 10 km/h; a reduction of diesel motor speed independent of driving speed; up to 30% less fuel consumption; and up to 20% more efficiency.