Freudenberg Sealing Technologies develops in-wheel motors with patented seal design

by Giulia Daniele

Freudenberg Sealing Technologies offers a patented sealing geometry to support original equipment manufacturers (OEMs) and manufacturers of electric motors ranging from electric cars to commercial vehicles right at the development stage.

Freudenberg Sealing Technologies

In-wheel motors (IVM) for electric vehicles offer various advantages. Elements such as transmissions, brakes and suspensions can either move much closer to the point of power transmission or be completely eliminated. IVMs also include wheel-specific torque control, enhanced comfort and more design space within the vehicle. This allows for a better driving experience, greater range and more flexibility for developers.

They are also a valid option for buses due to their lower centre of gravity, tighter turning radius and higher load capacity. They can offer added value as a combined trailer drive for e-trucks or as a generator for refrigerated trailers with independent power supply.

“The technical challenges for the seal are mainly to ensure reliable protection against dirt and water while minimising friction losses,” explains Product Developer Luca Breusa. “As a solution, Freudenberg has positioned the sealing lip in such a way that high contact pressure maximises sealing performance at low rotational speeds. At higher speeds, both the contact pressure and the friction are significantly reduced by the generated centrifugal forces. Depending on the customer’s requirements, the seal can even be fully lifted off the stator, which also eliminates friction, thus significantly increasing the lifetime of the seal,” Breusa explains.

The company has developed two seal designs:

With these two solutions, Freudenberg bridges the gap between the requirements for high sealing performance and low friction losses. The seal geometry can be scaled to an installation space diameter of up to 530 mm and is adjustable to the respective speed range. This allows the seals to be used in applications ranging from cars to commercial vehicles.

by Giulia Daniele