It’s an impressive development, not least because, according to ZF, no additional electric motor is required in the driveline for the start/stop – so cutting costs and reducing space requirements.
Details so far are scant, but the engineering design team claims that its start/stop is the first designed for demanding city bus applications and the most frequent engine torque requirements of 1,000—1,600Nm.
In action, it automatically switches the engine off when the vehicle is at a standstill, and then re-activates it as soon as the driver moves from the brake to the accelerator pedal.
The team says it has also strengthened the converter and lock-up clutch in the transmission.
Additionally, ZF’s EcoLife Coach transmission variant now accommodates an input torque of up to 2,300Nm for intercity buses and coaches.
Meanwhile, ZF’s AVE 130 electric portal axle for electrically driven buses has been further developed, with “significantly increased performance and torque values of the two motors close to the wheel”.
Maximum electric output of the two water-cooled, asynchronous motors integrated into the axle will increase from the existing two 120kW units to two 125kW machines.
At the same time, the effective nominal voltage of the electric motors will increase from 350 to 400V, while the maximum torque rises from two 465Nm to two 485Nm.
It’s another important development, allowing additional space for standing areas and seats since the rear drive and prop shaft are eliminated.