Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/757428
Proper power As with other types of equipment, graders have seen a steady rise in power. Unlike some other categories, this rise has been significant. Luke Kurth, grader product marketing manager with John Deere, says graders have seen the fastest power growth rate of any type of equipment, up some 40 percent in the past 15 years for Deere products. "Power is a key consideration because graders are drawbar machines." Some of that power increase is to handle the in- creased weight of Tier 4 Final compliance, which requires large, heavy aftertreatment components. To accommodate these components, manufacturers can lengthen frame rails or increase the size of the en- gine enclosure or both. On machines, such as wheel loaders, where maneuverability and rear visibility are essential, either solution creates problems. Because graders are less sensitive to these factors than are some other machines, one or both approaches may be used. Some manufacturers choose to lengthen the frame. But the combination of aftertreatment components and in- creases in frame length and sheet metal to house them creates significant additional weight, which requires additional power to preserve performance. One caveat in all this is that weight balance must be preserved in order to not disrupt the performance of the grader, says Wade Porter, motor grader market professional with Caterpillar. This may include adding weight to the front of the machine to compensate for additional weight at the rear. But these power increases are more than what's re- quired to merely compensate for Tier 4 Final, and cus- tomers are finding these new, more powerful machines can do tasks their predecessors could not. "Customers are doing more rough-in with their graders now," says Kurth, "where they used to bring in dozers for all but the final grading." The way power is used is just as important as the power itself. Front-wheel drive is one way to apply power more effectively. (Note that there is no standard term for this. It's front-wheel drive, all-wheel drive, 6-wheel drive, even front-wheel assist, depending on the manufacturer.) Power can be apportioned front-to- rear to suit conditions. For fine grading, drive can be front-wheel only and at very slow speeds. Front-wheel- only Precision Mode on Deere graders allows opera- tion from 0.25 to 5 miles per hour, with speed infinitely variable between those low and high limits. Transmission type also affects engine power require- ments. "Komatsu is unique in that we use a torque converter," says Rob McMahon, product marketing manager. "The torque converter multiplies the out- put of the engine, significantly increasing power to the ground." The dual-mode transmission operates in torque converter mode in mixed conditions, when the moldboard might strike a rock or other obstruction, EquipmentWorld.com | December 2016 23 All-wheel drive on the Case 865B AWD provides better steering and draft control in tricky underfoot conditions such as mud, snow and sand. Case says all-wheel drive is crucial for faster snow removal and attaining maximum perfor- mance in ditching and heavy blading applications.