AddiDrive™ for Truck

AddiDrive™ is an on-demand genuine hydraulic alternative to mechanical all-wheel drive. It consists of a hydraulic transmission in addition to the trucks’ standard mechanical transmission; it automatically transfers torque to a non-driven axle, only when additional traction is needed.

BENEFITS

• Maximized uptime thanks to added traction on-demand
• Lower fuel consumption comparable to a standard all-wheel drive truck
• Increased payload (> 500 kg) compared to mechanical all-wheel drive
• Same ground clearance as a standard truck
• Driver's peace of mind
• TCO decrease
• Boosted fleet productivity
• Safety and comfort
• Differentiation and truck range versatility
• AddiDrive™ operates in two modes: Freewheeling and Traction modes

FREEWHEELING MODE

When the truck is on a surfaced road, AddiDrive™ is switched off. The engine-powered pump remains in neutral and both motor lines are connected to the tank thanks to the control valve; motor pistons are maintained in their cavities. The mechanical axle provides 100 % of the traction.

TRACTION MODE

The driver switches AddiDrive™ on when exiting the surfaced road and going on to rough terrain. The system shifts to Traction mode. The control valve connects the pump lines to the lines of the motors, whose pistons roll now along the cam profile. The pump is controlled by the ECU to maintain speed synchronization between the hydraulic and mechanical axles. The mechanical axle still provides almost 100 % of the traction.

When the rear wheels start losing adherence, as both axles are synchronized, the hydraulic axle tends to turn faster than necessary. As the wheels are in contact with the ground, a resistance is created. The AddiDrive™ circuit pressure increases, and the hydraulic wheel motors take over, driving the truck forward. The front axle provides the necessary tractive effort to compensate the rear axle’s lack of grip, and prevents the rear axle from increasing its slip rate.

As soon as the rear wheels stop slipping, the circuit pressure is lowered, and the truck reverts to the mechanical drive. Thus, depending on changing traction conditions, the tractive effort is automatically balanced between the front and rear axles and the truck motion is insured. In traction mode, the hydraulic motors do not work against the truck brakes; when the driver brakes or decelerates, the ECU actuates the electronic bypass mode.

Besides the standard traction and freewheeling mode, AddiDrive™ additionally offers Creep and Boost functions.

BOOST AT START

When in Boost mode, the system brings the highest pressure as soon as the gas pedal is applied on a stationary vehicle, delivering the highest torque to take off the truck. Once the truck picks up speed, the circuit pressure decreases.

CREEP MODE

Creep mode is tailored for activities which require a high precision on a constant slow speed. Once the Creep mode is activated, the pump displacement is proportional to the driver command and to the engine speed, while the vehicle is driven exclusively by the hydraulic system at constant slow speed. The driver can set up the speed with cruise control, throttle pedal or joystick. When the targeted speed is reached, it will be regulated by the system, whatever the engine speed. Indeed, if ICE rpm increase to pilot auxiliaries, the pump swash plate is adjusted to keep constant the vehicle speed.

AddiDrive™ speed range in the traction mode is usually 0 up to 30 kph (0 to 18.6 mph), depending on truck and system characteristics. Above that value, the ECU automatically disengages the system.