The main components in the propulsion module are the electric motors (1) the bull gear (2), the brakes (3), and three planetary gear sets.
The gear train of the electric drive propulsion module receives power from two sources. One power input is from the electric drive motors for FORWARD or REVERSE movement. The other input is from the steering motor for steering control.
The two electric motors drive the bull gear through the drive motor gears (4).
The steering motor drives the steering planetary gear set through an idler gear (5) . The steering planetary increases the speed of one track and decreases the speed of the other track. The speed difference of the tracks turns the machine. The direction of rotation of the steering motor determines the direction of the turn. A higher motor speed results in a sharper turn.