DAF to build hybrid trucks

Posted on 11 Oct 2010 by The Manufacturer

The commercial vehicle manufacturer has said it will start production of the DAF LF Hybrid, a 12 tonne distribution truck with a parallel hybrid system, before Christmas.

This follows a field test where vehicles have been tested for two years in daily use with customers in Great Britain and on the continent. DAF is one of the first European truck manufacturers to put a hybrid truck into production.

PACCAR – DAF’s US parent company – has experience in the field of hybrid technology. In the United States, the Kenworth and Peterbilt brands offer a range of diesel/electric hybrid models. The DAF LF Hybrid truck was developed in collaboration with Eaton, Eindhoven University of Technology and Leyland Trucks Ltd, also a PACCAR company.

EEV diesel technology
The DAF LF Hybrid uses a parallel diesel/electric hybrid system, where the truck is driven by the diesel engine, the electric engine or a combination of both. The truck is fitted with the 4.5-litre PACCAR FR diesel engine, which complies with the ultra-low EEV emission requirements as standard, without a soot filter. In the LF Hybrid, this engine produces a maximum power of 118 kW/160 hp and is linked to an automatic Eaton six-speed gearbox (Autoshift).

An electric motor has been installed between the clutch and the gearbox, which can provide drive as well as functioning as a generator. Energy released during braking is stored in the lithium-ion batteries and reused when accelerating. Depending on the degree of charge of these lithium-ion batteries, a central computer determines when the diesel engine provides the drive and when and to what extent the electric motor is used.

Lithium-ion batteries
The battery pack for the hybrid system weighs around 100 kilos and consists of ninety-six 3.4 Volt cells. When these batteries are fully charged, the LF Hybrid truck can travel about two kilometres electrically without needing the diesel engine to drive it. In practice, this is enough to drive in and out of the “green zones“ in city centres. In these types of circumstances, the diesel engine also runs at idle in order to drive various components (such as the steering pump and the air compressor). The LF Hybrid is also fitted with a start/stop system.

In addition to the battery pack, DAF hybrid technology consists of a current transformer that converts the alternating current supplied by the generator to direct current for the batteries. A cooling unit is also fitted to the chassis to cool this current transformer. The DAF LF45.160 Hybrid is 300 kilograms heavier in total than the standard model with a diesel engine alone. The 12-tonne LF Hybrid offers a load capacity of around 7.5 tonnes.

DAF will start to supply the LF Hybrid in Great Britain, the Netherlands, Germany, France and Belgium; countries where market research has shown that the interest in hybrid vehicles is highest. Depending on the success of the LF Hybrid in these markets, the company says it will decide whether to include the vehicle in the standard product range in other countries.