Automated Systems Make Sure Trailer Tires Stay Pumped Up

Getting a flat can be more than just a hassle for truckers. Riding on a damaged or underinflated tire increases fuel consumption, causes excessive wear to treads and drives up operating expenses. Several companies are offering solutions.

Eaton and Meritor are hoping to eliminate the problem with automatic inflation systems that re-inflate tires while trucks are in transit. The companies are marketing products that essentially accomplish the same task, but work in different ways.

The tire maintenance system from Eaton of Cleveland re-inflates when sensors detect the air pressure of a tire dropping below a set level. A radio signal is sent from a transmitter on the tire valve to engage the system. Air is sent from the truck’s air brake supply through a series of tubes that connect with the tire valves.

The system, which is only available on trailers, uses rotating seals in the axle to inflate the tire while the vehicle is moving. In addition, a warning light on the nose of the trailer, and visible through the rearview mirror, alerts the driver of low pressure.

The device builds on Eaton’s monitoring system, which was released last year. Its earlier equipment could monitor air pressure but could not re-inflate the tire.

“While monitor systems are ideal for operations where the truck returns nightly, a maintenance system is a better fit for long-haul operators,” said Gary Schultz, product manager at Eaton. “The system also will significantly reduce the potential for failed casings that result from under-pressurized tires.”

Company spokesman Rich Zesiger said the system will not only make trucks safer by cutting down the potential for getting a flat tire, but it will save fleets money as well.

“Tires are a huge part of a fleet’s cost,” Zesiger said. “This kind of a system makes sure tires are at proper inflation, meaning they will live a lot longer and the fleet will save money.”

Meritor’s offering has a different design. The company, based in Troy, Mich., is marketing an automatic tire inflation system in partnership with Pressure Systems International.

The system sends a flow from the air brake supply to the tire through a network of tubes and valves that are similar to Eaton’s system.

Frank Sonzala, vice president of PSI, said the system sends a constant flow of air at a specific pressure to the tires, ensuring that their pressure never goes lower than a certain level. He said the risk of overinflation is low.

Once the tire pressure is greater than the flow level, Sonzala explained, air from the brake supply will lack enough force to enter the tire. When tire pressure is down, the air flow will resume until the two pressures are equal.

A warning light is also featured on the trailer to notify the driver when a tire needs additional air from the system.

For the full story, see the April 5 print edition of Transport Topics. Subscribe today.