Trelleborg launches seals that will help make next-generation electric cars a reality

Trelleborg Sealing Solutions has launched the HiSpin PDR RT and HiSpin HS40, two seals specifically developed for e-Mobility applications.

Engineered to operate at high velocity, they make a significant step in overcoming issues related to sealing at high rotary speeds that limit electric cars being able to meet the ultimate goal of travelling the same distance as a petrol or diesel vehicle on one charge.

The quest for an electric car that will be adopted in volume has intensified as manufacturers seek to lower CO2 emissions and retain vehicle access in some of the world’s most populous cities.

According to a report by the International Energy Agency, there were 3.1 million electric vehicles on the roads globally in 2017, but this number is expected to grow exponentially to at least 125 million and potentially 220 million by 2030.

This however depends on the existence of a viable technology that allows travel from one charge that is equivalent to a tank of fuel, giving car drivers the independence they are used to from traditionally felled vehicles, and the two new Trelleborg seals represent a significant step in making this possible.

Jan Zumbach, Head of Business Development for e-Mobility at Trelleborg Sealing Solutions, said: “With gasoline or diesel vehicles people know they will get where they want to get to. The infrastructure is there and filling up the tank is never an issue.”

“When people drive an electric vehicle they worry if they will have enough charge to arrive at their chosen destination, and a lack of charging points and the time taken to charge a battery make them nervous. The solution to this is to install a charging infrastructure and increase battery capacity to extend the distance hat can be travelled on one charge.”

“A limiting factor in achieving this is the seal in the e-axle. The new HiSpin PDR RT and HiSpin HS40 will contribute to extending the travelling distance of electric cars, helping make the mass adoption of these vehicles a reality, rather than a dream.”

The e-axle is a major technology in electric vehicles, and is a combined electric motor and gearbox that fit within the traditional engine space.

The motor and gearbox are directly coupled but while the gearbox requires efficient lubrication, it is essential that the motor remains dry and so a highly reliable seal is required between these two components.

Paul Taylor, Product Line Director at Trelleborg Sealing Solutions, said: “As electric motors run most efficiently at high speeds, the seal requirements are very different from those for a transmission input on a combustion-engine vehicle.”

“Gasoline engines normally run at 2,000 to 4,000 rpm, but the electrically driven transmission runs up to eight times faster typically at 16,000 rpm, and in the future this is likely to increase significantly.”

“The rotational surface speed limit for traditional seal in the e-axle of today’s electric cars is around 30 metres per second. The theoretical optimum rotational surface speed of the e-axle would be greater than 60 metres per second to maximise efficiency, a speed that is currently impossible to achieve.”

“Our aim for the new e-Mobility seals was therefore to increase operating rotational speed to at least 40 metres per second. We achieved this for HiSpin HS40 and an outstanding 60 metres per second with HiSpin PDR RT.”