23 Jul 2024


In-wheel motor developer joins forces with SKF

Protean Electric, which develops in-wheel motors for electric and hybrid vehicles, has formed a strategic partnership with SKF to supply critical components. The two companies also will look at other areas for collaboration.

The five-year strategic partnership will focus initially on a wheel bearing system with integrated sealing and sensors, developed for Protean by SKF. The bearing design will have a significant influence on the performance of the in-wheel motor, which has to operate in extremely harsh environments. Beyond this initial project, the companies will look for new areas of collaboration in the hybrid and electric vehicle market that capitalise on their expertise.

“We believe our in-wheel electric drive system will enable the widespread transformation of the global auto industry, and we are very pleased to partner with SKF, which is also a leader in its field,” says Protean chairman and CEO, Bob Purcell. “Only SKF can supply a bearing to meet the requirements for our unique in-wheel electric drive system. SKF also has the competence and skills to support the entire development lifecycle and series production.”

The Protean in-wheel direct-drive system (above) sits in the normally unoccupied space in a vehicle’s wheel, and delivers up to 800Nm of torque. The 81kW motors, each weighing 31kg, are claimed to deliver the highest torque density of any electrical propulsion system. Up to 85% of the available kinetic energy can be recovered during braking and the drive system is said to produce fuel economy improvements of up to 30% for a wide variety of vehicles, depending on the battery size.

The system can be retrofitted to vehicles currently on the road with minimal modifications. It is suitable for pure electric, fuel cell or hybrid elctric vehicles. The technology is already protected by 25 patents and Protean has applied for a further 84 national and international patents. 

The Protean technology is based on a pancake motor design originally developed in the UK by PML Flightlink. Protean, which has US and Chinese backing, has operations in the US, UK, Hong Kong and Germany. After raising $84m of funding last year, production of the drive system is scheduled to begin in China later this year.