Isuzu Hybrid truck prototype

While a lot of attention is focused on hybrid powertrains for passenger cars, the same eco-friendly system is also being considered for commercial vehicles. Of course, for commercial vehicles (CVs), the operating conditions are rather different; they have to carry much heavier loads and have to work for long hours in tough conditions. Therefore, the approach to hybrid powertrains for CVs has to be different and Isuzu Motors has been working on this for some time.

 

Their efforts can be seen in the N-Series Diesel Hybrid which is now on display at the KL International Motor Show (KLIMS 2010). Though still a prototype, the company has reached quite an advanced stage and is able to reveal the design of the powertrain which is a first for trucks in Japan.

 

The hybrid powertrain uses a long-life lithium-ion battery with a 346V capacity. It features a PTO-type parallel drive system in which the motor/generator is on a different axis from that of the engine. In this way, it is possible for the vehicle to be run using just the diesel engine. This provides a ‘back-up’ in the event of any problems with the electronics so that the vehicle is not totally stranded – something which fleet operators hate since that can mean a loss of time and money.

 

In addition, the motor/generator is mounted low on the chassis frame, thereby eliminating the need to have a raised floor. This eliminates wasted space which is very important for a cargo-carrying vehicle.

 

The 25.5 kW electric motor is especially strong so that there is enough torque to move the vehicle off smoothly and also to assist in acceleration when necessary. As with all hybrid powertrains, there is regeneration to recover energy that is typical lost during braking or decelerating. This energy can be used to recharge the battery continuously. The regeneration system utilizes the ‘Smoother-Ex’ automatic transmission which automatically disengages the clutch when decelerating, optimizing energy recovery till the vehicle comes to a stop.