Tires represent a major cost for any trailer fleet. So it's no surprise that automatic tire inflation systems continue to become more popular among companies seeking to control their operating expenses.
Meritor Tire Inflation System by PSI wants to answer questions about how pressure, temperature, mileage, road conditions, and load on trailers affect the performance of tires on vehicles equipped with automatic tire inflation systems.
“A fairly large amount of information is available about factors such as tire pressure, temperature, mileage, and load on standard vehicles,” said Gary Cunningham, PSI engineer. “Very little information is available about these same factors on vehicles equipped with automatic tire inflation systems. We are using our tractor/trailer to perfect our drive axle and steer axle inflation systems, wheel end temperature sensors, and evaluation of competitive and associated wheel end components.”
PSI recently equipped a trailer with dataloggers to record tire and hub cavity pressures. One is connected to the wheel with a specially fabricated hose from the valve stem to the datalogger. The other is connected to the hubcap and directly records hub cavity pressure.
The trailer completed a 24-hour road trip to test tire pressure under various road and temperature conditions. During the first part of the trip, tire pressure increased by about one PSIG over 100 miles while the trailer was empty. After a 20-ton load was added to the trailer, tire pressure increased by about six PSIG over the same 100 miles. During the test run, PSI also recorded varying hub cavity pressures — from a low of 1/10 PSIG to a high of about 1/2 PSIG.
PSI also is working on mounting a flexible thermocouple to a tire — similar to installing a tire patch — to directly record tire temperature. The San Antonio-based company displayed the tractor/trailer during a plant tour to celebrate its 10th anniversary.