I’m sometimes asked why Valley® builds its own gearbox. Often the question is “wouldn’t it be easier and cheaper to buy a gearbox from China like others do?” Well, yes, it would be easier and cheaper to buy a Chinese-built gearbox, but it wouldn’t provide the quality and durability growers need and expect from Valley.
That’s why, since 1974, Valley has manufactured its own gearbox at our facility here in Valley. More recently, we’ve increased our commitment to ensuring a reliable supply of Valley gearboxes with our new, state-of-the-art manufacturing facility in Waverly, Neb.
So, why does Valley go through the effort and expense to manufacture a gearbox itself?
Because building our own gearbox allows us to customize the design to meet the unique needs of an irrigation machine. For example, unlike other manufacturer’s steel worm gearboxes, Valley uses a ductile iron worm gear. Ductile iron has significantly higher wear capabilities because the surface of the gear has micro-pores that can hold lubricating oil. Also, the imbedded graphite in the gear itself provides some lubrication under extreme loads. That’s why the American Gear Manufacturer’s Association (AGMA) design standards allow 60 percent higher loads to be carried with ductile iron worms as compared to steel worms.
Valley also uses a 25 degree tooth angle in our gearbox. According to the AGMA, a 25 degree tooth angle provides 40 percent more strength at the root than the 14.5 degree pressure angle used by others. While a 14.5 degree tooth angle is wider at the top, don’t be fooled. A 25 degree tooth angle is wider at the root, where the strength is needed. Tooling for a 25 degree tooth angle is more costly because it’s not standard, but it’s worth it because it helps the Valley gearbox last longer.
The Valley gearbox also has a 52:1 gear ratio. This means the gearbox uses 4 percent less energy to move the machine through the field, but, more importantly, the design has a fully recessed tooth action. With a fully recessed design, the gears keep lubrication oil between the gears longer, reducing friction for increased load capacity and longer life.
Valley also uses U.S.-made, case-hardened bearings made from ultra-pure steel instead of through-hardened Chinese bearings used by others. Case-hardening provides superior wear characteristics while maintaining the inner toughness of the core material. As a result, Valley bearings have a 40 percent greater load rating.
But, even the best gear design and materials won’t help if the gearbox isn’t sealed from the elements. That’s why Valley uses a patented six-barrier input and nine-barrier output seal to keep oil in and problems out. Valley also uses a 2 inch longer output shaft to ensure mud and crop residue don’t damage the seal as the machine moves through the field. To compensate for this longer shaft, special wheels are used that actually move the center of the tire closer to the gearbox output bearing than the industry standard, reducing the load on the gearbox.
Finally, we also control the quality of each component and each step in the manufacturing process. A dedicated team of buyers, engineers, quality inspectors and machine operators works day and night to ensure each component meets the stringent Valley quality requirements. Because our suppliers are located in the United States, we can easily perform random inspections of their facilities to ensure they are meeting our quality standards. All major components are also machined by Valley, providing a second level of quality control. A final inspection is performed by testing each gearbox before it is shipped. And, to further ensure Valley quality, randomly selected gearboxes are life-tested in our gearbox testing laboratory.
All this adds up to a gearbox that is 24 percent stronger and lasts two-and-a-half times longer, ensuring you can apply the correct amount of water when and where you need it.
Our philosophy at Valley always has been to provide the most durable gearbox in the irrigation industry – even if it costs more. And this still holds true today. In fact, many folks around Valley consider the Valley Gearbox the “heart and soul” of the Valley machine.