Poclain Hydraulics AddiDrive(TM) Assist

Overview: an additional hydrostatic transmission offering trucks and convoys better mobility in difficult driving conditions such as: mud, snow, sand, etc. This hydraulic aid, installed on the front or rear axles is an ecological alternative to full-time all-wheel drive, engaging on-demand only when needed for higher torque and improved traction control. Providing dramatically reduced weight and improved center of gravity (because the cab height is identical to a non-driven front truck axle), improvements are realized in fuel consumption and additional payload while simultaneously improving vehicle stability and safety.


o The Market

o The Technical Solution

o Comparison with All-Wheel Drive Vehicles

o Present Results

The Market

AddiDrive(TM) Assist is designed for vehicles that occasionally operate in adverse conditions such as mud, snow, or steep grades.

Front Assist Drive on Tractors (estimated number of vehicles produced in Europe during 2006)
Road Tractor 300,000
Urban Service Vehicles (garbage collection trucks, delivery vehicles) 30,000
Emergency Intervention Vehicles (fire trucks, ambulances) 10,000
On Site Transporters of Material 10,000

Assist Drive on Trailers
8 Ton Axle Trailers
(concrete mixers, log carriers, military, etc.) 30,000

Comparison with All Wheel Drive Vehicles
AddiDrive(TM) Assist (on tractor) All Wheel Drive Vehicles

Performance / Consumption

Approximate mass of system
(2 motors + pump+ valve) = 120 kg Require heavier components
o transfer case
o front axle
o planetary gear
i.e. a total mass of 500 kg, increasing fuel
consumption and decreasing payload

The height of the vehicle is not Height of vehicles is increased due to front
increased (integrates into standard axle (+ 14 cm). Consequently, the center of
chassis) gravity is higher, reducing stability and

Freewheel without mechanical friction Drag torque due to friction between mechanical
so therefore minimal efficiency losses parts: ~ 15 kW, i.e. 5 - 10 % reduction in
fuel economy

Less wear on brakes and clutch


Control of vehicle in difficult
driving conditions (such as snow
covered roads)

Hydrostatic braking, acting as an Friction braking wear
integral retarder without using the
service brakes or separate retarder

All Topics