Drive assembly with pressure force aggregating piston arrangement for hydraulic motor speed/torque selector

A drive assembly for a final drive of a work vehicle, the drive assembly comprising:

• a mounting hub configured to secure to a frame of the work vehicle;
• a drive motor attached to the mounting hub, the drive motor having a rotor driving an output shaft;
• a swash plate pivotally mounted with respect to the mounting hub about the output shaft and movable into one of a plurality of tilt orientations corresponding to one of a plurality of motor speed settings;
• an actuator arranged to pivot the swash plate into one of the plurality of tilt orientations, the actuator including:
• a first piston disposed in a piston chamber of the housing for movement by hydraulic pressure along a stroke axis;
• and
• a second piston disposed in the piston chamber of the housing for movement by hydraulic pressure along the stroke axis, the second piston being arranged in contact with the first piston and configured to aggregate and transfer forces from hydraulic movement of the first piston and the second piston to pivot the swash plate;
• a gear set coupled to the output shaft;
• and
• an output hub receiving rotational power from the motor via the output shaft and the gear set to provide motive power for the work vehicle;
• wherein the output hub is driven at a first speed and torque when the swash plate is in a first tilt position and the output hub is driven at a second speed and torque when the swash plate is in a second tilt position.