Electric Controls for Powershift Transmissions

In the past twenty years there have been extensive changes in the design concepts of heavy-duty vehicles. For instance, vehicle size has been increased, some vehicles are articulated, and some are multi-powered. These new vehicle designs with their complex geometry and often remotely-located power plants have made the range selection of the Powershift transmission difficult. Mechanical shift control systems have shown certain limitations in controlling the new vehicles and are being replaced with other system types which are controlled by air, hydraulics, or electricity.

A new electric shift control system is presented in this paper. This control is easily adaptable to the new vehicle concepts and offers the additional advantages of shift inhibiting and increased transmission durability. Because of its flexibility and built-in safeguards, this system offers many advantages that should lead to its wide acceptance in future vehicle designs.