Drives and Controls Magazine
Supercar motor delivers ‘record’ performance
Published:  01 February, 2022

The Swedish supercar manufacturer Koenigsegg has developed an electric motor that combines radial (power-dense) and axial (torque-dense) flux topologies to produce a machine which, it claims, delivers the best torque-to-power-to-weight ratio available. The car-maker says that its Quark motor is smaller and lighter than any other in its class, with the first production version weighing just 30kg, yet capable of producing up to 250kW of power and 600Nm of torque.

Koenigsegg argues that its Quark motor rethinks the fundamentals of magnetism, materials, cooling and packaging. Although the “raxial flux” motor has been primarily developed to power the company’s four-seater Gemera hybrid-electric “mega-car”, the company sees potential uses for the “torque-rich” ultra-compact motor in other EV powertrains, and for applications in the aerospace, marine and other sectors.

Koenigsegg has also integrated two of the Quark motors with a “revolutionary” six-phase inverter and planetary gears, to create a torque-vectoring EV drive, called the Terrier – also claimed to be “class-leading”.

In applications where there is no need for a step-down transmission, direct drive will be possible. “Small high-revving motors can have higher peak power-to-weight ratio, but they need transmissions in most applications in order to get to the desired output rpm and torque, causing energy loss and adding weight and complexity to do the same job, so any benefit in size is lost,” explains Koenigsegg’s founder and CEO, Christian von Koenigsegg. “In other cases – like the Terrier application – the transmissions can be reduced in size and complexity compared to higher-revving, less torque-dense motors, which is also a big win. I guess we’re trying to reach the edge of optimal in-betweeness.”

András Székely, who led the motor development programme, explains how the designers overcame weight penalties. “We constructed the shaft within the Quark out of 300M steel used in motorsports and aerospace. Direct cooling was chosen for its higher cooling efficiency and compact design.” The motor’s rotor is based on the Aircore hollow carbon fibre technology that Koenigsegg already uses for its wheel rims, steering wheels, seats and other components.

“We not only overcame the challenge of the Gemera’s powertrain requirements but also exceeded goals of making it lighter and smaller than any electric motors in this class,” Székely continues. “The Quark presents new benchmarks in compact and torque-rich engineering… Without the extra driveline functions for the Gemera, the Quark can drop below 28.5kg in weight.”

The Gemera will use three of the electric motors – one driving each rear wheel, while the third will be combined with a 500hp three-cylinder internal combustion engine (ICE) to power the front wheels. The total output will be 1.27MW. The drive system will deliver more than 11kNm of torque from a standstill and will be able to accelerate the vehicle up to 100km/h in 1.9s, and on up to 400km/h using a single gear. The car will have an electric-only range of up to 50km, and a total range of 1,000km. The first deliveries are planned for 2023.

Koenigsegg claims that its Quark motor sets new benchmarks for performance

“The Quark motor is designed to bolster the low-speed range of the Gemera, where you need it, for brutal acceleration," explains Dragos-Mihai Postariu, who led the design of the motor. “The ICE then focuses on the high-speed range. What this means in terms of performance for the Gemera is a big power surge followed by a continuous record-speed push to 400km/h without any torque or power losses.”

The Terrier integrated EV drive needs only one inverter (instead of two), because its six-phase inverter provides three phases for each of the two motors, thus reducing weight, size and component counts “drastically”. The inverter slots between the two flat motors to create a high-density square package. Because the motoes deliver power and torque at low speeds, small low-ratio, efficient planetary gear sets can be used for each output.

The compact packaging allows the Terrier to be elasto-bolted directly to the monocoque or chassis, potentially avoiding the complexity of added subframes or weight.

Founded in 1994, Koenigsegg Automotive develops and manufactures performance megacars and sustainable mobility technologies. It has around 500 employees.

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Power and torque curves for the Quark motor