Coelho, R. and Rabelo, T., "Clutch 430 Heavy Duty," SAE Technical Paper 2011-36-0257, 2011, doi:10.4271/2011-36-0257.
Extra heavy vehicles, depending on their application and configuration, demand higher torque, longer drive-off time, many gear shifts, more complex and unusual maneuvers. These situations lead to a high thermal energy applied on the clutch, increasing clutch wear and, in extreme conditions, leading to a thermal destruction. These events demand a technically and economically viable solution as well as a compact layout for easy implementation to increase the clutch performance and life. Since the problem is of thermal nature, without the possibility of forced cooling or the use of a larger clutch assembly to faster dissipate the energy, the proposed improvement has been focused on faster energy absorption in order to minimize peak temperature, both in occurrences and in magnitude. With a 430 mm single-disc clutch set, keeping the interface layout, being compatible with the actuation system and with an thermally optimized pressure plate, the goals of lowering peak temperatures, occurrences of critical temperatures as well as being easy to implement and economically viable, resulting in improved durability and reduced occurrence of thermal destruction, were achieved. First of all, with energy controlled, this new concept was 16% better than conventional clutch (without fading and thermal destruction), but on the truck, it presented even better results. Applied on Heavy Trucks with 74 tons; medium (~ 6%) and high (~ 11%) grades routes, full load travel (load factor of 100%), driven only by top drivers, the clutch disc wore just 10% after 200.000 km. That means in particular conditions; the clutch disc becomes a "lifetime" component.