Switchable front-wheel drive for DAF CF and XF

New drive system for road-going trucks that occasionally have to operate in off-road conditions

FOR trucks that clock up most of their mileage on the road but are sometimes required to drive off road or in slippery conditions, DAF are introducing a robust hydraulic front-wheel drive system that can be activated at the flip of a switch on the dashboard.

This new ‘PXP’ drive has been developed together with Paul Nutzfahrzeuge and will be available on the DAF CF and XF 4x2 tractors powered by the PACCAR MX-11 or MX-13 engine. Other chassis types will follow later in the year.
 
Permanent all-wheel drive for a truck that drives off road only occasionally, usually means a considerable cost in terms of acquisition, maintenance and fuel consumption. However, it is sometimes very important to have extra traction to tackle ditches, sandy roads, unpaved tip sites and steep inclines.

In challenging situations like these, if the vehicle registers slip from the powered wheels, PXP – ‘Paul Xtra Power’ – is automatically activated. The greater the amount of slip from the rear, the more traction the front wheels provide.

DAF’s switchable front-wheel drive is available in the first four forward gears and the first and second reverse gears. At speeds above 20km/h (and/or in fifth gear and upwards) PXP switches back to stand-by mode. The system activates itself again at lower speeds and whenever use is required.

To make the switchable front-wheel drive possible, each front axle wheel hub is equipped with a hydraulic motor, producing torque of no less than 6,435Nm at a maximum system pressure of 360 bar. This ensures optimal performance and optimal longevity and reliability.

A unique feature is that the motors are driven by a hydraulic pump that is fitted directly on to the engine-PTO, which saves both weight and space. In addition, the hydro pump can also drive components such as cranes, hook arms, stabilizers and skip-loader systems for maximum efficiency. This means that only one hydraulic tank is required, which also results in less weight and more space.