Porsche announces new technology partner

By CARSIFU | 12 February 2015


STUTTGART: Porsche has awarded GKN Driveline “Technology Partner”, thanks to the company’s development of a high-performance eAxle for the advanced plug-in hybrid 918 Spyder supercar.

The eAxle module in mention supports full-electric mode, all-wheel drive and even provides a boost function.

“GKN Driveline’s role in the development programme and its innovative eAxle module has earned the company Porsche Technology Partner status,” said Porsche powertrain manager Christian Hauck.

The eAxle that supplements the 918 Spyder’s hybridized 4.6-litre V8 is an evolution of the company’s innovative eAxle drive.

The module has a maximum power of 95kW and can deliver up to 1,500Nm of torque to the front wheels via a fixed gear ratio.

A specially developed compact differential engages the torque seamlessly, giving the 918 Spyder optimum power distribution at all times.

The differential also disengages the module to minimise drag losses and maximise efficiency.

Porsche 918 Spyder - 02 GKN eAxle
At speeds above 265kph, a clutch isolates the electric motor to prevent it from over-spinning.

A key target for the 918 Spyder was to have the lowest possible centre of gravity and ground clearance.

To achieve this, it required an original engineering solution where GKN Driveline positioned the output overhead by using an innovative lubrication concept to manage the oil flow.

The oil reservoir is positioned above, not below, the geartrain.

Oil is gravity-fed down onto the bearings and gears until it reaches the high-speed input at the bottom where it is then circulated back to the oil reservoir at the top.

This design minimises the amount of oil on the input shaft, keeping churning losses to a minimum.

To ensure the critical areas remain lubricated even in disconnect mode, the motor is driven for brief, intermittent intervals to maintain a constant flow of oil.

The Porsche 918 Spyder’s tight packaging also means there is almost no air flow around the transmission and so water cooling was needed to manage the heat generated by the module’s high power density.







Keywords