Page 17 - Industrial Technology EXTRA - 22nd June 2020

xford YASA Motors is engaged in the A 500 Nm YASA motor has already been
development and manufacture of a new developed specifically for use in electric and hybrid
type of axial flux motor that features vehicles. This motor is compact – just 340 mm in
OYokeless And Segmented Armature diameter and 70 mm wide – and is, therefore, able
(YASA) topology. Compared with conventional axial to fit easily within the space that would normally be
flux motors, the new YASA types offer a step-change occupied by the front or rear differential in typical
improvement in torque density, making them ideal vehicle. With the YASA motors, no differential is
for applications such as electric vehicles where the needed.
highest possible torque-to-weight ratio is a key Since these motors have an output of 500 Nm
requirement. per “slice”, and a peak power of around 75 kW, two
The YASA topology is based around a series of of them provide sufficient power for most vehicles.
magnetically separated segments that form the This has been verified in practice by the Westfield
stator of the machine. The step-change iRacer, a pioneering electric racing car fitted with
improvement in the specific torque of the motor, two YASA motors, which accelerates from 0 to 60
which at around 20 Nm/kg is at least twice that of mph in less than 5 sec, and is capable of reaching
the best currently available alternatives, results from an electronically limited top speed of 110 mph.
a combination of patented improvements in the Despite the impressive performance and
magnetics, cooling and packaging of the motor. versatility of its existing products, Oxford YASA

June 2020 • INDUSTRIAL TECHNOLOGY EXTRA! • p17