Don Foulke, Industrial Sales Manager, Firestone Industrial Products
Compressed-air bellows have long been major players on farm equipment, but now they’re showing they can help in force control, too.
In 1900, many farms dotted the American landscape. They were small and diverse, and according to a report issued by the U.S. Dept. of Agriculture, employed 41% of the American workforce and an estimated 22 million work animals. Today, the U.S. agriculture industry paints a very different picture. Modern farms are large, specialized and highly mechanized. They employ a fraction of the workers the industry required a century ago, and work animals have been shown the door. By 2000, less than 2% of the employed labor force in America worked in agriculture—freeing these would-be farmers to work in fields other than those that grow crops. Notably, the efficiencies gained throughout the past century have also made food more affordable in the U.S. and abroad.
Demands to produce more for less are always in play. As agriculture continues to be asked to produce more food more efficiently for more people, key technologies are being used so farmers can meet this demand. The introduction of air springs into the agriculture arena is one such advance that has helped the business of farming evolve.
Adaptive use of air spring technology
Air springs are an adaptive technology that was originally developed in 1938 as pneumatic suspension devices for light-duty vehicles. Yet, these sophisticated rubber and fabric products have been used for technologically advanced actuation and isolation solutions for a broad range of non-vehicular applications for years. About four decades ago, air springs entered into the agriculture market in dairy and crop handling applications, and more recently, they have helped improve the way seeds get planted, not to mention the ride of tractors.
So, exactly what are air springs? Essentially, they are rubber and fabric bellows that contain columns of compressed air that provide support, stability, protection and more. They are constructed out of fabric-reinforced rubber with metal enclosures to be a sustainable option in the market. While the material itself does not provide force or support (it is the compressed air operating inside that does that) it is exceptionally enduring—a fact that has been proven both in the field and through formal, rigorous testing. A handful of manufacturers produce similar styles of air spring products; however, Firestone was the original developer of the technology.
As an example, standard air springs consist of four layers: the inner layer of rubber, which contains the air, the first layer of fabric-reinforced rubber, a second layer of fabric-reinforced rubber that supplies the strength, and the cover to protect the bias fabric plies. Depending on the rubber used in the air spring, these products can withstand temperatures from 65 to 225° F.
Air springs are closed systems that never corrode and are operable in naturally dirty, dusty environments—such as farms, where soil and the elements are constantly a factor. Because air springs are sealed units, they last a long time and don’t require a great deal of service. These heavy-duty balloons contain no moving parts, are friction-free and give immediate response in the form of force or compliance. Air springs take in and release air to maintain the proper amount of force and support to whatever object may be applying pressure. They can serve as actuators, vibration isolators or support springs, depending on the requirements of the application.
Air springs on the farm
On the farm, air springs are being used in hay balers, planters and cultivators, conveyor and vibrating screens, dairy barn parlors, cab mounts on heavy equipment, and irrigation systems. Obviously, the adoption of the technology has become quite pervasive across applications.
The technology’s latest hit on the farm is as actuators for down force control. They were first used in minimum tillage equipment, as farmers sought effective ways to plant with minimal disruption to the soil structure. Soon thereafter, air springs were used in planters, where the technology has been adapted to aid in sowing seeds at the correct depth. This is perhaps the most common use of air springs in the industry today.
A typical application of the technology at work in planters is within pneumatic down force control modules. These modules help farmers maintain consistent seed depth directly from the comfort of the tractor cabin. It is the same technology that allows buses—with the flick of a switch—to lower and rise so passengers can board more easily.
Historically, planter systems were hands-on, labor-intensive pieces of equipment. Even when tractors entered the main stage, farmers had to manually adjust planter equipment by hand to get the force needed based on soil conditions. This took a lot of time and physical effort, because details like seed spacing, consistent depth and the right amount of seed-to-soil contact matter a great deal to farmers interested in cultivating a healthy crop.
Fortunately, apparatuses like seeder pneumatic systems came about. These particular systems employ a row of air springs that are fed by a small electrically driven air compressor and a down force control module that helps create the appropriate pressure within them to keep the planter head at the correct depth in the soil. The air springs serve as actuators that help the machine handle terrain and soil density changes. Specifically, the air springs could be inflated or exhausted as the soil changes from sandy to heavy clay. This keeps the seed planter head at the correct depth to ensure the best germination and crop production rates.
Regardless of whether used on a tiller or a seeder, air springs adjust automatically to changing soil conditions and requirements with just the right amount of down force on the cultivator wheel or planter head. Plus, they perform exceptionally well in corrosive, abrasive environments, and even accept and easily accommodate misalignment.
Air spring applications expected to grow
Whatever the application, air springs can make farm equipment work better. Consider hay balers: This equipment benefits from the friction-free, leak-free, flexible-force properties that enable air springs to adjust belt tension in such a way that maintains bale density and applies constant force as the bale diameter changes. In dairy barn milking parlors, the technology provides years of trouble-free performance for the essential flush valves and dairy stall automation equipment. When used in conveyor systems, air springs isolate and reduce vibrations as produce moves down the line, whether it’s fruits, vegetables or grains. Even tractor cabs experience smoother, more comfortable rides thanks to the heavy-duty balloons.
The agricultural equipment of today operates at higher speeds and is more common on the road than ever before. The list of air spring applications will only grow in time as the agriculture industry continues to produce more food in more economical, efficient and ergonomic ways. The possibilities for this technology are endless.
Next up, the developing world
To date, air spring technology has mostly been adopted into the Western (developed) world. However, it behooves agriculture equipment engineers and manufacturers to look at where the cost and efficiency of food production is most needed: developing countries.
In many developing countries with large populations, the available arable land is being overrun by mega-cities. These cities are eating up the best farmland. In the meantime, demand for food is growing substantially thanks to exponential growth in the global population and rising incomes in emerging markets. It is imperative that the highest degree of agricultural technology is adopted and employed in these areas—it is the only way to sustain a population whose growth is overrunning farmable land. The use of pneumatic down force control to maximize yield is one of those technologies that is ecologically friendly, energy efficient and effective in the environment of a remote farm community. It has been a boon in Western agriculture, and so it could be for countries around the globe.
Firestone Industrial Products
firestoneip.com
Filed Under: Pneumatic Tips