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Repairing Gears 

Man fixing gears

Sometimes, creating a new gear simply isn’t an option. Replacement is costly, and worse, it can often take weeks to produce a new gear and ship it to a customer. Repairing your gears, however, may be the most efficient option, and the one that saves you the most in terms of lost production time. Is repairing your broken or stripped gear the best option to get you back up and running? Read on to learn more from the experts at Illinois Pulley & Gear.

Challenges of Building up Worn Gears

Let’s start with the obvious: everyone faces the un-relinquishing constraints of time and money. If we had all the money in the world, perhaps there would be no need to repair worn down gears once their age started to show. We could keep new and identical copies in our expansive warehouses. The same goes for time – if we never faced a deadline, or never had to stop production on our machines, we could meticulously repair our old gears until they were as good as (or better than) new. However, we live in the real world, where we almost always need to repair gears in the most time sensitive and economically efficient way.

Whether you’re dealing with a first to market prototype or a delicate custom gearbox, the process of building up worn gears always presents a few trials. Due to the challenges involved in building up worn gears, most gearboxes can’t always receive top of the line rebuilds. And unfortunately, after all is said and done, some gears simply can’t be properly repaired after all.

Fixing Cracks in Gears

If a gear has a bad crack, for instance, it will likely require complete removal and replacement. It can also be next to impossible to repair weld teeth on other gears. While some repair shops are capable of valiant efforts, the longer term results are not always the kind that can withstand the test of time. After any item is welded—in the wake of post weld relief—a comprehensive look over must be conducted to detect cracks in the item.

Rebuilding and Repairing Large Gears

Some larger gears have very complicated and intricate hub configurations, and these can also post a challenge in building up worn gears. It may be possible to accomplish repair through a process that begins with removal of all the gear’s teeth. After the teeth have been removed, the hub can be machined to serve as the center for a pinned steel tire, which can in turn serve as a blank for newly made gear teeth. This pinned steel tire must be shrink-fitted, however, to ensure that it will not rotate around on the hub, rendering the gear nonfunctional. It can seem daunting to calculate the fit amount you will need to prevent the tire from rotating on the hub, but you can use the formula required for a keyless coupling joint. All in all, this process can certainly take up a lot of time, but it is a sound choice for a reliable repair.

Rebuilding Gear Teeth

If the teeth on a gear have been worn down, it is possible to resurface them if the root filets of the gear are still in solid shape. While grinding down the roots of a gear can pose some challenges, it can be done. Surface hardened gears present yet another dilemma: the consideration of the reduction in case depth.

Worn teeth can be re-surfaced so long as the root filets are sound. When presented with gears of standard proportions, conversion of the gear to long and short addendum design is possible through a process involving the creation of new mating pinions. It can be a good option to create small pinions from barstock that already exist in inventory. These gears can then be recut while mounted on the shaft. The entire process is relatively efficient in regard to time, It’s also comparatively safe, in that the repair process can be performed without damage to other parts during disassembly.

Spur Gear Repair

Spur gears are the most common type of gear. Whether a few teeth are missing or worn down, or your spur gear is completely stripped, repairing spur gears is essential to keeping your machine functioning at its best. When repairing spur gears, it is often possible to machine new teeth. A top concern is that all teeth are kept even following repairs. If teeth are not uniform, force will pull on the teeth in an uneven manner. This will cause wobbling, and teeth will break yet again, until the gear is rendered circular.

Fixing Plastic Gear Teeth

Gears are made of many types of materials. Plastic gears are typically less expensive than steel gears, however, sometimes it is more beneficial to fix a plastic gear with missing or shredded teeth than it is to simply buy a replacement. Plastic gears often protect motors and gearboxes, and getting a new one in could take weeks or longer to produce and arrive. Plastic welding is an effective way to repair your existing plastic gears and get them back in tip-top shape. The most attractive incentive to fixing plastic gear teeth? From start to finish, the entire process generally takes under an hour, as compared to the lengthy process of building a new custom gear.

In the welding process, instead of gluing on new pieces, plastic can actually be reformed to create new grooves, ribs, and teeth. Another pro of plastic welding is that you can be sure your newly repaired gear will be just as strong as the original, since it’s comprised of the same plastic.

Illinois Pulley & Gear: Your Gear Experts

Illinois Pulley & Gear (IPG) is a custom pulley manufacturer with the goal of providing high-quality products in efficient and economic ways. Our primary products are Gears, Timing Belt Pulleys and Timing Pulley Stock, and we create a wide range of gear and pulley stock for a slew of industries, including Aerospace, Agriculture, Automotive, Power Transmission, Automation, Robotics, Packaging & Labeling, Food Processing, Medical/Pharma, Wire Processing, 3D printers, Equipment and Machine Components, and so much more!

At Illinois Pulley & Gear, we are passionate about producing high-quality timing belt pulley systems and gears that are built to last. Every timing belt pulley and gear is made-to-order to customer specifications, depending on your precise need. We are client-oriented and ready to listen. To inquire about your business’ specific needs, reach out via our online contact form or give us a call at 847.407.9595.