A bespoke development of GKN’s coaxial eAxle powers the rear wheels of the LEVC (London EV Company, formerly known as London Taxi Company)’s electrified TX model.
GKN Driveline launched its coaxial eAxle in its first application across Volvo’s range of T8 Twin Engine plug-in hybrids, picking up an Automotive News PACE Innovation Award in 2016. In these models, GKN’s system has an axle-split secondary drive role, with a 60 kW e-motor providing motive power to the rear wheels, working in conjunction with a combustion engine that drives the front wheels. (Earlier post.)
In the LEVC TX, GKN’s eAxle is always the primary drive unit, and so uses a more powerful 120 kW e-motor. A small gasoline engine at the front of the taxi provides range-extended power to the battery pack only, which means the taxi is always powered electrically by the eAxle.
The TX’s pure-electric driving range is around 80 miles (129 km), according to official test figures, while the gasoline generator boosts the total range up to 377 miles (607 km).
As with all GKN Driveline systems, the coaxial eAxle for LEVC has been specifically engineered to achieve the desired characteristics for the vehicle’s dynamics. The core design of the eAxle is shared with Volvo’s plug-in hybrids, but its bespoke features meet a totally different set of driving requirements. The lightweight unit weighs less than 17 kg (37.5 lbs) and has a mechanical efficiency of up to 97.5%.
Components within GKN Driveline’s coaxial eAxle designs are tightly packaged, with the reduction gearbox, open differential, driveshaft section and e-motor sharing a connected housing. This level of integration has significant benefits when it comes to packaging the eDrive unit within the new taxi’s chassis.
As the range-extender combustion engine is never providing power directly to the rear wheels, the TX does not need a propshaft, which delivers further advantages for weight and packaging.
Production of the electrified LEVC TX is already underway at a new facility in Ansty, near Coventry. The new taxi meets stricter Transport for London licensing requirements that come into force on 1 January 2018, which mandate a minimum 30-mile zero-emission range and maximum CO2 emissions of 50g/km for new taxis on the road.