Seals for the Mobility Sector

Seals play a crucial role in the mobility sector, whether in cars, ships or aeroplanes. (Source: Pixabay)

In the mobility sector, seals play a crucial role that is often underestimated. They are essential components in a wide range of applications, from automobiles to trains, and even aerospace vehicles. Their primary function is to protect various materials and systems from external influences while ensuring the functionality and safety of vehicles. Seals prevent the leakage of liquids and gases, protect against dust and dirt, and significantly contribute to the efficiency and longevity of technical systems.

The demands on seals in the mobility sector are high and varied. They must withstand extreme conditions such as temperature fluctuations, vibrations, pressure changes, and chemical influences. The ongoing development in areas such as electromobility, autonomous driving, and lightweight construction requires innovative sealing materials and technologies. In addition to technical performance, seals must also meet the growing demands for sustainability. The use of recyclable materials and the reduction of CO2 emissions during production are becoming increasingly important.

Freudenberg's CTIS systems are installed directly in the wheel hub to protect them from environmental influences. (Source: Freudenberg Sealing Technologies)

The future of sealing technology in the mobility sector is characterized by innovation and technological progress. New materials, such as high-performance polymers and elastomers, as well as advanced manufacturing processes like 3D printing, offer enormous potential for improving the performance and reliability of seals. At the same time, digital developments, such as simulations and artificial intelligence, enable more precise design and optimization of seals. These trends promise continuous advancement that will sustainably influence the mobility sector in the coming years.

Seals Regulate Tire Pressure for Safe Driving

Freudenberg Sealing Technologies offers seals for Central Tire Inflation Systems (CTIS) that automatically adjust tire pressure. With the push of a button and without having to leave the vehicle, drivers can adjust the tire pressure to changing ground conditions. This saves CO2 and also extends the life of the tires.

Whether in agricultural fields with a tractor or driving a truck on the road, tire pressure significantly affects performance. Properly inflated tractor tires save fuel, enable farmers to work faster, and reduce soil compaction. In contrast, overinflated tires cause soil damage and reduce efficiency. Likewise, a truck with the correct tire pressure is much safer on the road. Improperly inflated tires promote wear and also make vehicle handling more difficult.

Properly inflated tractor tires save fuel, enable farmers to work faster, and reduce soil compaction. (Source: Pixabay)

Freudenberg Sealing Technologies addresses these challenges with its range of seals for various CTIS heavy-duty applications. The manufacturer combines its expertise in materials and design with advanced electronics and sensor technologies to meet the specific requirements of heavy-duty applications. The systems provide an automated CTIS function and are installed directly in the axle applications on the vehicle manufacturer's assembly lines.

“The seals for central tire inflation systems from Freudenberg adjust the tire pressure comfortably to the ground conditions without the drivers having to leave their cabins and manually operate CTIS systems. This saves time and offers significantly more safety for the drivers,” says Jens Wolfram, Global Segment Director for Mobile Machinery Agriculture at General Industry. “Current systems with external lines are prone to premature failures because their components are at risk due to system or line damage. Freudenberg's CTI sealing solutions are positioned in the wheel hub, thus not exposed to external influences during agricultural processes. A decisive advantage and a unique selling point compared to external systems of competitors.”

Maximum Adaptability

CTIS must meet high and very individual requirements depending on the application. Freudenberg's seals adjust the tire pressure simultaneously to road and ground conditions as well as the vehicle load. The systems save fuel, reduce vehicle wear, and lower vibrations for a more comfortable driving experience.

Freudenberg's CTIS technology includes a new double-lip sealing component that is mounted inside the wheel hub. This way, the oil in the wheel hub is separated from the compressed air flowing into the tires, allowing the system to take in the air flowing to and from the tire. An external hose mounted on the tire is therefore unnecessary.

The students of the EPFL Racing Team build a new racing car every year. (Source: Angst+Pfister / EPFL Racing Team)

An air lip ensures stable CTIS function up to 8 bar at a circumferential speed of up to 45 m/s. The pressure- and speed-optimized seal reduces vehicle power loss. Compared to other tire inflation systems, the Freudenberg system balances air pressure on both sides of the sealing lip, which results in significantly lower power losses. The resulting force minimizes the radial load on the sealing lip.

Seal Manufacturer Supports Swiss Racing Team

Ambitious and with many vehicle innovations, the “EPFL Racing Team” aims to reach the top in Formula Student. For this, they invested in a more powerful high-voltage battery. A Swiss seal manufacturer supported the project with material and expertise. Formula Student is a competition for aspiring engineers. Student teams from over 50 countries and hundreds of universities design and build their own racing cars for this competition, earning points in static disciplines as well as in dynamic events on the racetrack.

The "EPFL Racing Team" was formed at the École Polytechnique Fédérale de Lausanne (EPFL) in 2017. It first participated in competitions in 2019. Today, the team consists of around one hundred students and built its fourth racing car, “Ariane,” for the 2023 season. The EPFL Racing Team builds a new racing car every year: Design starts in September, and the cars are ready for use by May. In June, a testing phase follows, and from July, the competitions begin. The drivers are selected during an internal karting event in Switzerland.

The competitions are held partly on renowned racetracks like the Hungaroring or the Hockenheimring. (Source: Angst+Pfister / EPFL Racing Team)

“With Ariane, we wanted to catch up with the leading teams,” says Etienne Hofstetter, who is responsible for the high-voltage battery with his team. In the first few years, they managed to make it to the midfield. Key factors for success on the track include the acceleration, maneuverability, and reliability of the cars. On relatively short straights, they reach around 100 km/h.

Strict Inspections for Competitive Assessment

The competitions are held partly on renowned racetracks such as the Hungaroring or the Hockenheimring. They last for a week and begin with inspections of the vehicle. Only those who pass these inspections are allowed to participate in the dynamic competitions. For example, there are concept presentations to judges that evaluate engineering competence and business acumen. Tests also include acceleration on straights, and the endurance race is the grand finale. Efficiency is also assessed: How much energy do the cars require for the time achieved?

Participation is governed by a complex 130-page rulebook, most of which revolves around safety. "For the new season, the association increased the requirements for battery construction concerning fire protection standards," says Etienne Hofstetter.

This involves structural plastic parts that hold the soldered battery cells together and protect them. Until now, the team had ordered the material for this from the online shop of the seal manufacturer Angst+Pfister, so-called POM-C plates, and then manufactured the parts themselves. The battery team now needed materials compliant with the UL94-V0 fire protection standard to meet the 2023 rulebook requirements. This standard requires materials where flames must extinguish within ten seconds and glow for no more than thirty seconds afterward. “A search revealed that the previous POM-C does not meet the fire protection standard, but we could not afford high-performance plastics like PEEK. We needed a lot of raw material that had to be milled,” says Etienne Hofstetter. So he turned to Angst+Pfister.