MAN, a major player in the commercial vehicle industry, makes a revolutionary breakthrough with the launch of the HydroDrive®, a hydraulic assistance system for on-road trucks. Poclain Hydraulics partnered with MAN from the beginning of the project, as Peter Frick, the HydroDrive® Project Manager, explains.
POCLAIN HYDRAULICS: “When did you come up with the idea of the HydroDrive®?”
Peter Frick: “Poclain Hydraulics actually initiated the idea by presenting in 1989 a system they had baptized Ecodyn® and whose purpose was to assist on-road trucks with a hydraulic transmission. The idea matured in our minds and on the drawing board. Several technical challenges needed to be resolved along the way. The first prototype was built in 1999, and we asked customers to test and give their input on our solution. The resulting HydroDrive® system was launched on the market in the fall of 2005.”
POCLAIN HYDRAULICS: “What is the HydroDrive® exactly? “
Peter Frick: “It is a front-axle assistance that kicks in when the truck needs additional tractive force to maintain adherence, such as on a grade, on slippery or unconsolidated terrain. The system’s major components are: an electronic controller, a gear unit with an integrated clutch connecting the pump to the main gearbox, two Poclain Hydraulics MFE08 rotating case hydrobases, a fixed displacement pump and a valve block. It is engaged or disengaged on-the-fly via a switch conveniently located on the dashboard. When the rear axles start skidding, the pump sends the excess hydraulic flow to the motors, which generate torque and enable the truck to maintain adherence. The front wheel assistance automatically disengages when the truck reaches 28 km/h and reingages under 23 km/h.”
POCLAIN HYDRAULICS: “Which trucks are available with the HydroDrive® option?”
Peter Frick: “MAN offers the HydroDrive® on the 18 to 35 ton segment of the TGA range. It is available on the 2, 3 and 4 axle models. It targets specialty trucks such as tippers, tank tenders, timber transporters and fire fighting and rescue vehicles. They travel most of the time on the road at high speed and occasionally require an all-terrain transmission. The HydroDrive® transmission is the perfect solution, as it provides additional torque when the ground conditions require it, yet it does not hinder the truck’s performance on the road: when the assistance is disengaged the hydraulic motors free-wheel and generate no horsepower loss.”
POCLAIN HYDRAULICS: “What are the advantages of the HydroDrive® system in comparison to the conventional mechanical all-wheel drives?”
Peter Frick: “There are several: first and foremost it improves the owner’s bottom line – its light weight gives him 400 kgs additional payload and its high efficiency optimises fuel consumption: 10% below a mechanical all-wheel-drive. The truck’s center of gravity is also lower as there is no mechanical axle or propshafts at the front. As a result it is more stable and allows for easier load handling and cab access.”
POCLAIN HYDRAULICS: “How did Poclain Hydraulics contribute to the project?”
Peter Frick: “They initiated the idea at the beginning and co-developed the system with us. The combination of our expertise, us in utility trucks, them in hydraulic transmissions, enabled us to transcend the technical challenges and design a system which is simple, seamless and highly efficient. Their assistance goes beyond the production line – their local Training Center expert has trained our service technicians to intervene efficiently on the field.”
POCLAIN HYDRAULICS: “How has the market reacted to your new product?”
Peter Frick: “The market’s response exceeds our expectations. The HydroDrive® answers a need that was yet to be satisfied. It is particularly popular in areas with harsh weather conditions or hilly terrain. Given its success, we are considering offering it on a wider range of MAN trucks. “