Development of Automatic Transmission for 120 Ton and 160 Ton Dump Truck

As a direct result of the mining industries need to improve efficiency and production in open pit type operations, the size of dump trucks has increased. In addition, the increase in vertical lift and resultant grades, and the in crease in hauling distances are making the demand for mechanical drive dump trucks. With these mining requirements, we have developed the mechanical automatic transmission, controlled by microprocessor, with 8 forward speeds and 1 reverse speed, which suit 120 mton class dump trucks and 160 mton class dump trucks. This paper shows the design concept and progress made in development of these transmissions.