Those fleets that specify air ride systems for trailers probably already know that the benefits of the systems go far beyond protecting cargo. A smooth ride helps mitigate vibration damage on the undercarriage and body of trailers and limits jarring wear on doors, liftgates and lighting systems, just to name a few, and they help to provide a better ride for drivers—bottom line—less physical stress on humans and equipment.
According to Great Dane Trailers, suspensions it offers provide customers with a number of benefits. The trailer maker notes that its air spring suspensions are available in a wide range of designs to further improve ride charac-
teristics and operational features while also reducing cost and weight.
While all air spring suspensions use air pressure rather than a steel spring to support the weight of a trailer, they can be very different in terms of their design. There also are differences in the types of air springs used by suspension manufacturers. Most common are convoluted and rolling lobe designs.
All air spring suspensions work by adjusting the amount of air in the air spring to maintain a constant ride height. By varying the pressure in the air spring, the stiffness of the spring is matched to the load.
This ability to adjust the stiffness of the spring to the load means that a lightly loaded trailer will be supported by a softer suspension and ride more smoothly. In addition to offering ride quality improvements, the pressure in an air spring suspension is proportional to the load in the axle, making the use of on-board scales practical.
The continuously adjustable nature of the air spring suspension also allows for it to be designed with features to aid in the loading and unloading of the trailer, and greatly reduces the amount of floor movement when a forklift enters or exits the vehicle.
Air spring suspensions are offered with a number of options, such as retractable supports, which greatly restrict the movement of the suspension when that capability is desired.
Steel suspensions still have a place in certain applications. For any particular axle load, there will be an ideal stiffness that provides the best ride and minimizes excess trailer motion. But a steel spring designed to support 20,000 lbs. per axle will be much stiffer than needed if the trailer is lightly loaded. The result is much harsher ride quality when the trailer is lightly loaded, which can result in cargo shift and damage, as well as wear on the trailer.
According to the trailer maker, specifying the correct suspension for each application remains an important objective. Considering an air spring suspension, like those offered by Great Dane, may afford customers a number of benefits.
