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FW-EVX: Williams Advanced Engineering's new lightweight EV platform concept. (Williams image)

Williams presents lightweight EV platform

Williams Advanced Engineering has joined the rapidly expanding world of electrified vehicle R&D. The company recently unveiled a lightweight, high performance platform concept created to be capable of supporting multiple vehicle types and multiple wheelbases, and facilitating significantly longer range.

Designated FW-EVX, it uses weight saving materials specific to task. The platform incorporates an energy storage system and electric powertrain, including a modular battery concept.

The U.K.-based company, best known for its four decades of Formula One expertise, is in the process of “reimagining” how electric cars are designed and constructed, not only to make them lighter but also to ensure they are safer, greener, have longer range and better overall performance, via innovations in battery pack design (the battery module width is 136 mm/5.3 in), cooling systems that are aerodynamically efficient via forcing air through sills and also incorporate crash energy absorption, and structures. All this comes together on a scalable platform.

Paul McNamara, the Technical Director, explained: “These technologies, and our thinking around how to create a tightly integrated, lightweight chassis and powertrain package, have the potential to greatly increase the competitiveness of the new generation electric vehicles.”

Exoskeleton battery module

One area of development involves what the Williams engineers describe as a “highly automated, near-zero waste process” to create fiber-reinforced suspension components for the FW-EVX to deliver a weight reduction of up to 40% compared to a regular aluminum wishbone.

Also, part of its R&D concerns forming 3D structures from 2D materials, in this instance used to build an exoskeleton for a battery module. It is said to contribute to the structural performance of the battery.

Essentially, the FW-EVX platform has been created to meet high performance, low volume applications while using industry-available powertrain components. However, because of its scalability, high-volume applications would also be within its scope.

Although revealed in all-wheel drive form at the recent Low Carbon Vehicle (LCV) exhibition at Millbrook, U.K., a rear-drive-only configuration is said to be easily achieved.

As shown at Millbrook, front wheel drive has a single YASA P400 motor contributing 160 kW (214 hp) towards a total output of 480 kW (644 hp). It also incorporates Xtrac’s new P1166 transmission. At the rear there are twin YASA P400 motors (320 kW429 hp/ combined) driving through an Xtrac P1227 transmission that facilitates torque vectoring.

The demonstrator platform, with nominal 2800-mm/110-in wheelbase, has useable energy capacity of 80 kW·h and LG pouch-type battery cells (10 cells per module, 38 modules) with 2.1 kW·h per module). The module design has been constructed to allow use of multiple formats. Honeycomb is used for modules/structural modules. The platform has an 800V system.

Carbon fiber is, of course, an excellent but usually costly lightweighting solution, so major systems have been designed to use aluminum pressings/ hydroforms and fabrication, states Williams. Weight of the 955 kg/2105-lb platform shown at Millbrook was broken out as follows: passenger cell 340 kg/750 lb; mechanical powertrain 150 kg/331 lb; power electronics/charging 35 kg/77 lb; modules/busbars 100 kg/220 lb; cooling system 70 kg/154 lb; chassis/suspension 180 kg/397 lb and wheels 80 kg/176 lb.

For a 1750-kg (3858-lb) vehicle and with a standard energy total of 80 kW·h, Williams’ calculates NEDC range as 552 km (343 mi).

Pursuit of 'silent' drivetrains

The FW-EVX project “represents a new direction for Williams Advanced Engineering’s business, as its own R&D team has developed the proprietary innovations and has submitted patents for a number of innovations,” noted Craig Wilson, Managing Director.

James Setter, Head of Xtrac’s Automotive and Engineering Business Unit, commenting on his company’s involvement with the FW-EVX concept, said there is considerable intellectual property to be gleaned from advanced automotive technology development programs, in particular "the pursuit of silent drivetrains."

Xtrac quotes a mass of 17-20 kg for its P1126 and 28-45kg (37 to 44 lb) for the P1227, dependent on configuration. Tight packaging was a design criterion for each. Both are rated for a maximum speed of more than 10,000 rpm and peak torque of 1000 N·m (737 lb·ft). The P1126 uses a bevel gear set and differential while the P1227 has a transverse motor installation with helical gears, enabling it to fit with single or dual motor inputs to be configured as a differential or to deliver torque vectoring.

“Either transmission can fit a front or rear axle,” explained Setter. “It’s all about flexibility in the package to meet requirements!”

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