Technology: Trelleborg develops "next-generation" seals for EVs

Stuttgart, Germany – Trelleborg Sealing Solutions (TSS) has launched two new seals specifically developed for electric vehicles (EVs) applications.

The HiSpin PDR RT and HiSpin HS40 have been designed to operate at high velocity, addressing the issues surrounding sealings’ performance at high rotary speeds, said Trelleborg 18 Feb.

Designed to help increase the travelling range of electric vehicles, the two seals are expected to contribute to the "mass adoption" of EVs.

The new products have been developed for the e-axle, which according to TSS e-mobility head Jan Zumbach is "a key limiting factor in EVs".

The e-axle is a combined electric motor and gearbox that fit within the traditional engine space.

The motor and gearbox are directly coupled; however, while the gearbox requires efficient lubrication, the motor should remain dry.

Here, a “highly reliable seal” is required between these two components, added Zumbach.

While addressing that problem, the new seals also offer an increased rotational surface speed.

As electric motors run most efficiently at high speeds, their seal requirements are very different from those of a combustion-engine vehicle, explained Paul Taylor, product line director at Trelleborg Sealing Solutions.

According to Taylor, the rotational surface speed limit for traditional seals in the e-axle is around 30 metres per second in EVs today.

Theoretically, this figure should be greater than 60 metres per second to maximise efficiency of an electrically driven transmission, which runs typically at 16,000 RPM, Taylor added.

TSS therefore aimed to develop seals that could increase operating rotational speed to at least 40 metres per second, Taylor added.

“We achieved this for HiSpin HS40 and an outstanding 60 metres per second with HiSpin PDR RT,” he concluded.

According to Colin Macqueen, who led the seal development programme, the two products were developed in eight months.