Why Material Selection Matters for Bearings and Beyond
Bearings and similar components often have serious implications for the performance and...
Agriculture is one of the oldest industries in existence. It’s also one of the first industries to be systematically mechanized. Ever since the popularization of iconic inventions like the McCormick Reaper, mechanized agricultural equipment has played a central role in helping this sector grow more food to serve a growing population while keeping prices as low as possible.
Compared to some industries, agriculture involves many different highly specific production processes: growing grapes looks very different from growing grain or vegetables, for example. And each of these processes comes with a need for highly specialized equipment.
This large number of equipment niches means a large number of OEM’s designing and manufacturing products for often highly specialized applications. Almost all of this equipment faces challenging operating conditions, including heat, dust, and operating (literally) “in the field,” where regular maintenance is challenging and prohibitive for operational efficiency.
In this article, we first take a look at some of the broad categories that define the diverse world of agricultural equipment.
We then take a look at some of the key challenges faced by that equipment.
Finally, we look at how self-lubricating component materials can help directly address some of these fundamental challenges. We conclude with some specific case studies on real ag-equipment success stories for TriStar components like bearings. For a more broad overview of the agriculture industry itself, please see our blog post here.
Agricultural production centers on a series of different operational phases. Each of these phases introduces needs for different types of specialty equipment. For some crops, these phases play out across an annual cycle. Other crops may be grown multiple times per year.
Agriculture involves a huge variety of crops and unique growing techniques, from grain fields to cranberry bogs to orchards, and the list below is necessarily generalized. For instance, tree-based crops like fruit may not require annual re-planting but will require other maintenance tasks like pruning.
While laying out these phases linearly helps organize our discussion, it’s important to realize that there can be substantial overlap between each of the phases below. For instance, fields may be carefully re-plowed to remove weeds after seeds have been planted.
While self-propelled equipment has become somewhat more commonplace, the tractor often remains the common piece of equipment behind all of these categories. Because the multi-part production process of agriculture requires so many different pieces of equipment, maintaining separate vehicles for every aspect of production is often cost-prohibitive.
By using equipment that can be attached and pulled behind a tractor, the same vehicle asset can be leveraged across as much of the production cycle as possible. The tractor is the main workhorse for the farm, pulling a wide range of implements across each of the categories outlined in this article.
Wheeled tractors were historically dominant, but tracked systems have increasingly become a leading alternative: tracks help distribute weight more broadly to minimize rutting/soil disruption.
The equipment pulled behind a tractor often has a mechanism for drawing power from the tractor itself. This mechanism can involve couplings attached to the tractor’s transmission or a “power take-off,” which most commonly incorporates a specialized drive shaft on the tractor which can be attached to the equipment.
“Tillage” refers broadly to soil preparation via mechanical agitation. Originally performed by hand-tools like hoes, and then animal-drawn plows, tilling equipment for commercial-scale agriculture is almost always mechanized today.
Key Goals of Tilling
Tilling equipment can be designed for either primary tillage (deeper, more thorough tillage) or secondary tillage (shallower and more selective). Primary tilling, like plowing, leaves the soil with a relatively rough surface finish. Secondary tilling is employed to help level and smooth the rough surface to create a more ideal seedbed. Primary tillage is usually conducted after the previous harvest has been completed. Secondary tillage can be conducted during the growing cycle if needed (for instance, to help integrate fertilizer with the soil or control weeds).
Due to these different tasks, secondary tilling equipment often requires more precision. For instance, it may be required to till between crop rows to eliminate weeds without damaging the crops themselves.
To maximize yield, seeds cannot be simply scattered across the ground. In addition to needing to be spread in an optimal amount and density, seeds need to be secured at a certain depth within the soil (the exact depth depends on seed type, soil, and climate variables). Seeding carefully within a pattern like a row is also important, as this geometry allows for mechanized weeding between crops.
Traditionally, seeding equipment centers around the use of a seed drill, a hopper filled with seeds arranged above a set of tubes which are spaced to help optimally spread seeds using rotating fluted paddles. While primitive seed drills have been used since Ancient Babylon, British inventor Jethro Tull famously created the modern, mechanized seed drill in 1701 (his device was horse-drawn but utilized a mechanical seed apparatus).
Today, seeding equipment most typically works using air injection, a technique that is not only more reliable and precise but can even be used in untilled soil (some regions work to minimize tilling to help preserve soil and prevent erosion).
While the terminology is often used inconsistently, today a “seed drill” is typically used to refer to equipment used to spread smaller seed types. A “planter” is used for large seeds. Either way, modern seeding equipment is prototypically tractor-drawn. Other common terms include “grain drills,” “precision planters,” and “seeders.” All of these terms describe the same general operating concept.
Fertilizer is essential for both maximizing immediate crop yields by providing key nutrients and protecting the long-term health of the soil. It can be applied both during tilling and after the crop has been planted. Extensive fertilizer use has been a key driver of a general increase in agricultural productivity over the last 60 years that has been instrumental in feeding the globe’s growing population.
Fertilizer can be generated both organically (eg. manure) or through chemical synthesis. Either way, specialized equipment is required to spread it over crops/soil. The amount of fertilizer required will depend on the fertility of the soil itself and the crop type. The key difference for fertilizer application equipment is liquid v. solid.
Pesticides and herbicides are other key substances that need to be distributed over crops and/or soil. We cover this equipment here because it is most often distributed through sprayer-equipment of the same general design used to distribute liquid fertilizer. Spraying equipment can range from small, backpack-borne equipment to large tractor-drawn equipment.
Harvesting machines are highly crop-specific. Generally, they are designed to mechanically pick and load a crop. The huge variation in crops, however, means that harvesters have to be very carefully designed to match the needs of the crop in question. In short, picking a pineapple from a tree is an extremely different process from pulling a potato out of the ground.
Each mechanized harvester is typically named after the specific crop it is designed for. However, various grain harvesters are typically referred to as “combines.” Harvesting is one area where engineers are still working to mechanize a large number of processes. While some areas, like grain, have proven amenable to harvesting machinery, others, like delicate fruits, remain dominated by manual labor.
For some crops, the method employed depends on how the crop will be utilized. For example, tomatoes that are going to be processed (eg. into ketchup, sauce, or paste) can be mechanically harvested, but tomatoes for fresh conception are far more likely to be manually harvested to help protect their aesthetic qualities.
With all this variation, the volume and speed of harvesting equipment can vary substantially. While conveyor belts help transport picked fruit with minimal bruising at relatively low volumes, large combines process grain on the order of tons per hour.
Agriculture equipment exhibits a huge diversity, as the examples above demonstrate. Even within a single category, like combines, many different designs and mechanical variations may be employed.
Virtually all agricultural equipment, however, finds common ground in a core set of engineering challenges. Ag-equipment OEM’s have to deliver designs that carefully accommodate each of the challenges below.
TriStar offers bearings and similar vibration- and impact- absorbing components engineered from advanced, self-lubricating polymer materials. In our experience, these materials have proven incredibly valuable to agricultural equipment manufacturers.
They can not only help enhance the reliable lifespan of components but save on maintenance costs by eliminating the need for regular greasing. Most of all, these components help keep equipment in the field, generating ROI for agriculture operators.
TriStar brings multiple agriculture-friendly materials to the table, including Rulon, TriSteel, Ultracomp, and CJ composite. These diverse offerings allow ag-equipment OEM’s to carefully match the desired material properties to the task at hand.
These materials help directly address each of the engineering challenges above.
There is no one perfect bearing material for every application. Rather than resorting to broad preferences for one material across all equipment and components, materials should be sourced based on careful analysis of the challenges they will face in the field. This analysis should include maintenance needs, expected lifespan, and the consequences of premature failure.
For a more detailed look at material specifications for each of TriStar’s offerings, please see our Interactive Materials Database here.
Below, we provide some more details on how our materials have helped solve key engineering challenges in a wide variety of agriculture equipment.
Challenge: this harvesting equipment OEM makes conveyor belts and suspension cylinders on tractor-mounted boom lifts used for harvesting produce (like pineapples) in steep, hilly terrain.
They required bearings that could last longer in all-weather conditions and resist acid-driven corrosion.
Solution: TriStar identified our Rulon J material as the most effective solution. Rulon J offers low-abrasion for protecting sensitive produce and is compliant with soft-mating surfaces. It also resists stick-slip in start/stop applications like this one. Rulon J has excelled, with our client reporting increased efficiency and productivity, and all while eliminating manual greasing.
Challenge: a major sugarcane producer sought out TriStar’s help: sticky sugar cane pulp was becoming “glued” to metal bearing journals inside crushing equipment. These bearings required constant greasing and frequent cleaning. This elevated level of maintenance was introducing prohibitive supply, labor, and downtime costs. Meanwhile, they were operating in constant fear of a bearing seal failure that could contaminate huge volumes of product in their high volume (7000 tons of raw cane daily) production line.
Solution: TriStar identified Ultracomp UC500 bearings with reinforced fibers, combining a binding resin with graphite migratory lubrication. Our fabrication team also improved the seal design at both ends of the journal and eliminated the ingress of sugar onto the bearing surface.
Challenge: a client was struggling with cost-prohibitive steel bearings used on the undercarriage, steering column, and control arms of their riding lawn mowers. Meanwhile, end-users like farmers complained they simply didn’t have time to constantly re-grease these metal bearings.
Solution: Our engineers studied the issue and identified TriSteel bearings to replace steel-on-steel units. This solution provided enhanced component life, zero maintenance, and was a cost-effective replacement for steel throughout the equipment. Meanwhile, end-users no longer had to worry about the hassle of regular maintenance.
This paper has examined how self-lubricating polymer components like bearings can solve some of the most common engineering pain points for agriculture equipment. TriStar materials provide advantages that are relevant to much of the diverse array of equipment found in the farms and fields of the global economy. For components expected to thrive in the demanding, competitive agriculture sector, material selection matters.
We never present composites or advanced polymers as a one-size-fits-all solution. Materials perform their best when they are carefully engineered to match the challenges of the operating environment where they are expected to thrive. Rather than treating bearings as commodities to be sourced from the cheapest bidder, an engineering-driven approach to component selection almost always pays off over the long term. In many cases, alternative materials can offer both cost and performance advantages compared to traditional materials like metal. In other scenarios, a nominally cheaper metal bearing may end up having a far greater lifetime cost if it fails prematurely compared to a better alternative
TriStar believes in adopting a true consultative engineering approach with all of our clients. The right bearings can not only solve chronic pain points but in many cases solve problems that engineers never knew they had. Our engineers are known to spend extensive time on site, studying client applications up close to determine the right materials for the job.
We take pride in providing this same level of attention to clients of all sizes. This approach is especially important in agriculture equipment, which features many smaller companies that design and manufacture more specialized products (in our experience, these specialized firms are often overlooked by large bearing manufacturers chasing high-volume accounts).
If you have questions about how TriStar’s self-lubricating components can help solve engineering pain points for your agriculture equipment, we recommend reaching out to our team using the button below.