The duty cycles performed by ultra-heavy off-highway machinery are among the most arduous in the industry. Off-Highway Machinery’s Duty Cycle Challenges How to handle the massive loads placed on the transmission and driveline components hat are the most demanding operating conditions in the automotive field? The frantic 90 minutes of flat-out 18,000 rpm action of a Formula One racer and its hot-shifted seven-speed transmission? The engine of a German businessman’s car as he hurtles down the Autobahn at a steady 250 km/h or perhaps the relentless stop and go of a city-centre taxi in the stifling heat of a tropical summer’s day? W Engineers may debate the finer points of each of these and many other situations, too, but it is a fair bet that some of the more knowledgeable would include the duty cycles performed by ultra-heavy offhighway machinery as among the most arduous in the industry. These frequently enormous machines, many weighing in at hundreds of tonnes, have immense power and torque and are worked to their full capacity on some of the most aggressive duty cycles 6 LUBRIZOL DIGITAL MAGAZINE SEPTEMBER 7 2011 AL MAGAZINE SEPTEMBER 7,, 2011