Williams Advanced Engineering has revealed details
of the FW-EVX, a lightweight electric vehicle platform that will be displayed
at JEC World 2018 in Paris. The platform was first previewed at last year’s Low
Carbon Vehicle Event, and draws upon the company’s expertise in Formula One and
Formula E.
According to the company, the FW-EVX is readily
scalable for C-, C-D- and D-segment vehicles, and boasts innovations relating
to cooling systems, lightweight components and the assembly process. In terms
of cooling, the bonded aluminium and carbon composite centre module of the
FW-EVX platform includes chassis side rails that provide cooling air for the
battery pack, as well as being controlled crush zones to absorb impact in a
crash.
The air is collected through ducts at the front of
the vehicle, which is then channelled to internal radiators before exiting at
the rear via an aerodynamic diffuser. This approach not only reduces
aerodynamic drag normally associated with heat exchangers, but the exiting air
can be used to help create downforce.
To further increase the efficiency of the cooling
system, the battery modules feature an aluminium base plate that is attached to
the thermally conductive vehicle floor that acts like a heat sink. “The high
level of integration creates a virtuous circle where each improvement in weight
and functionality leads to additional benefits,” said Paul McNamara, technical
director at Williams Advanced Engineering.
On the mention of the battery, Williams developed a
new method of creating an engineered hinge embedded in a single composite
preform, which allows 3D structures to be created from 2D materials then folded
when required.
The company calls it the 223 process, and it is used
in the construction of the low and slim battery module, which consists of
ultra-stiff honeycomb of interlocking composite boxes containing the battery
cells.
Each box is manufactured in sheet form, before being
folded and bonded to create the required shape. This production method creates
a tough ex-skeleton that contributes to structural performance, and in turn,
crash protection as well.
The FW-EVX platform also uses weight-saving
composite materials to reduce heft, like the suspension wishbones –
press-formed from 80% recycled carbon composite that are 40% lighter than
aluminium forgings while being comparable in cost to produce. The wishbones are
produced using a highly automated, near zero waste process called RACETRAK,
which has a cycle time of just 90 seconds.
In a typical C-segment application, the platform
weighs just 955 kg, and that includes the all-round wishbone suspension, up to
four electric motors (one for each wheel), 4WD transmission, steering and an 80
kWh lithium-ion battery pack weighing 350 kg.
The company is targeting two sets of customers for
the FW-EVX – carmakers looking for a next-generation EV platform that brings
the benefits of highly integrated design, and those seeking specific areas of
technology for their own platforms.