Trelleborg Sealing Solutions has engineered a seal that only seals around the axle of central tire inflation systems when required; when the tire is pressurized to inflate or deflate it. Conventional seals for central tire inflation systems are constantly in contact with a vehicle's axle all of the time, wearing the seal and causing friction that uses energy, thereby consuming fuel unnecessarily. By eliminating friction when the tire is not pressurized, Turcon® Roto L prevents unnecessary energy loss, cutting fuel consumption appreciably.
"The most obvious advantage of the Turcon® Roto L sealing concept is that seal life is extended," says Holger Jordan, Manager Fluid Power Technology at Trelleborg Sealing Solutions head quarters in Stuttgart, Germany. "Only operating perhaps 10 percent of the life of the vehicle's axle system, it means the seal is going to provide total system life sealing. More importantly though is that friction is eliminated when there is no pressurization. This saves energy and leads to significant fuel savings for the vehicle operator."
Turcon® Roto L combines a polytetrafluoroethylene (PTFE) sealing lip with a rubber jacket and a stable shape forming metal part. The seal's patented design means that for the majority of the time the sealing lip is held up against the sealing surface but not in contact with it. The seal is only activated when the system is pressurized. Then, the pressure causes the sealing lip to press against the sealing surface until the pressure is relieved. Afterward the jacket of the seal, acting like a spring, brings the sealing lip back to its original position.
As the seal has less than half the friction of a conventional seal for central tire inflation systems, its use also allows the vehicle operator to deflate and re-inflate tires when the vehicle is on the move. It can take between 20 and 30 minutes to adjust the pressure on large commercial tires. If this can be done while the vehicle is moving between jobs, that's up to 30 minutes that the commercial vehicle can be working rather than idle, further lowering a vehicle operators overall costs.
Though Turcon® Roto L was originally developed primarily for off-highway vehicles, Frank Kleemann, the product manager for the seal, believes there are other applications where it can provide benefits to users.
"We're talking to truck manufacturers. Turcon® Roto L seal makes the extension of tire inflation systems possible and we see particular benefits on long-based and multi-trailer trucks where tire pressures could be optimized to road and load conditions. This would improve traction and safety, and potentially result in considerable fuel savings for transport companies.
"Performance cars are another target. When super sports cars drive slowly, the tires should be kept at low pressure. At high speeds the cars will perform better if the tire is at high pressure, or different on each wheel, depending on the track it is travelling on."
Central tire inflation systems are commonly used on the axle of agricultural and off-highway vehicles. The pressure of a vehicle's tires is increased or decreased depending on the surface a vehicle is travelling on or the field or site the vehicle is working in.