The following is a look at how F couplings are put together – and why they’re so reliable:

1. Resilient grid. The grid on the Falk F coupling is made of high-strength steel, which has been quenched and tempered to spring hardness. The grid is primary load-bearing component, and its ability to flex is what allows the coupling to accommodate shock loads.

2. Cover. The F coupling is protected by a heavy-duty steel cover that floats on the hub teeth and allows free articulation of the grid. It also features wide flanges and narrow shrouds to make assembly a snap.

3. Hubs. Made of high-grade steel, the hubs have teeth that interact with the grid but are not attached to it, allowing each hub to correct shaft misalignment by shifting without imposing a load on the other.

4. Seals. The interior of the F coupling is protected by synthetic seals that are impervious to oil and grease. Their wide shoulders prevent lubricant loss as well as bar water, dust and other contaminants from entering the coupling.

In some cases, it may be possible to find a similar new model that will work in the discontinued drive’s place; in other situations, such as when a factory configuration is highly customized, accommodating a newer model may be prohibitively expensive. When this occurs, facility managers typically have two options:

Shop for Surplus Gear Reducers

The best recourse may be to contact a supplier with a large inventory of surplus gear reducers. Surplus dealers are frequently able to replace obsolete drives with refurbished or surplus gear reducers of the same model. Here at Mar-Dustrial, we’ve compiled a large inventory of surplus gear reducers and other surplus parts over the years. Chances are, we have the obsolete gearbox you need – or, if we don’t, we can usually find someone who does.

Rebuild the Existing Drive

If no equivalent surplus gear reducers are available, the next best option is to rebuild your obsolete gearbox. This is why it pays to work with a surplus dealer (like us) that also doubles as a Repair & Renew facility; if we can’t replace your drive, we can rebuild it for you on the spot. Our skilled technicians will thoroughly clean and analyze your gearbox, replace any worn-out parts – including all bearings, seals, shims and gaskets – and restore it to original specifications.

Here’s a look at some of the design features that make parallel shaft reducer maintenance easier:

Large inspection cover. Falk’s parallel shaft reducer is horizontally split, with a large inspection cover so technicians can easily examine its inner workings and perform routine maintenance.

In-place repair. This gear drive’s split design also allows for in-place repair, without the need to drain the lubricant or remove any elements. This means repairs can be accomplished more quickly and affordably, reducing the amount of downtime required.

Smooth surfaces. With its smooth, flat surfaces, the Falk parallel shaft reducer is much easier to clean than other gearbox models.

Outer cover assembly. The parallel shaft reducer also features an outer cover assembly, which, when filled with grease, traps contaminants before they can enter the drive.

Hansen is a leading global manufacturer of industrial gear drives, with service centers located in several countries. Hansen gearboxes are used in a wide range of applications, including mixers, kilns, pumps and conveyors in a variety of industries, such as mining and pulp and paper mills.

Our highly trained technicians have 25 years of experience with Hansen gearbox repair. We work on all types and sizes of Hansen gearboxes, including the UniMiner and other specialized drives. We enjoy working on this brand because of Hansen’s commitment to providing excellent service and helpful product information.

Our Hansen gearbox repair services include:

Inspection. All Hansen gearboxes sent to us for repair are steam cleaned (to prevent exterior contaminants from mucking up the inspection process) and disassembled for a thorough inspection to determine the cause of failure.

Failure analysis. As part of our repair estimate process, we report on the condition of the gearbox; list possible causes of failure as well as recommendations for curative measures; and provide a summary of repair work needed.

Complete refurbishing. The housing and all of its components are then stripped of all grease, paint and other contaminants, and the condition of each component is assessed before reassembly. All oil troughs and passageways are checked to ensure unobstructed flow, and gears are inspected for invisible cracks. We then install all-new bearings, seals, shims and gaskets using only original manufacturer parts. The Hansen gearbox is then reassembled to factory specifications in a clean environment.

So the next time you need a Hansen gearbox repair, consider letting our Repair & Renew facility handle the job.

Being blasted through an airlock separates the wood fibers even more, and then depleted cooking chemicals and unneeded parts of the wood are washed away. Depending on the final purpose, the remaining pulp may be bleached (for white paper) or left brown (for paper grocery bags, etc.). This pulp is then sprayed onto screens and shipped off for further processing to a different mill.

As you can imagine, large investments are required to build pulp and paper mills, and large amounts can be lost to downtime when mill equipment malfunctions. Indeed, if a gearbox or gear reducer breaks, the cost of downtime can far exceed the part’s original cost. Yet it’s not unusual for paper and pulp equipment to fail, since the environment within mills is often extremely hard on equipment. Turning wood into pulp is an extremely harsh process, especially in chemically powered plants. Elevated humidity and high operating temperatures, combined with harsh chemical baths and dusty working environments, compel pulp and paper mill engineers to choose tough, top-quality equipment.

Certain brands stand out in the paper and pulp mill manufacturing field for their reliability and exceptional quality. The following is a look at why Hansen gear reducers are considered some of the most dependable, long-lasting parts in the paper and pulp industry.

About Hansen, Gearbox Manufacturer

Since 1923, Hansen Industrial Technologies has worked closely with clients in a range of industries. Decades of experience (and several unique gearbox patents along the way) have positioned Hansen well for creating reliable parts that will keep on running in the harshest of working environments.

All Hansen parts meet or exceed ISO 9000 standards. Low noise levels, minimized operating cost, and energy efficiency are the manufacturer’s top priorities, along with exceptional engineering and technical support. With Hansen offices on six continents providing parts and maintenance, you’ll have no problem finding support for that new Hansen gearbox.

Distinguishing features of Hansen Gear Reducers

1. Dry well housing. Contamination is a major no-no in paper and pulp mills. If any oil or other outside substances leak into the pulp, an entire load could be destroyed. To prevent this situation, Hansen gearboxes offer dry well housing, which prevents oil from leaking down vertically oriented shafts.

2. Horizontal split housings. Hansen gear reducers are designed with horizontal split housings, which make it much easier to access and maintain parts.

3. Durable paint. The standard epoxy paint system for Hansen gearboxes is strong enough to withstand tough working conditions; humidity-resistant paint is also available.

4. Continuous oil circulation. Perpetually circulating oil running throughout Hansen gearboxes and other Hansen parts fosters long operational life and dependability.

 5. Easy oil sampling locations. Covers on Hansen gear reducers are located conveniently, so sampling is a breeze. And you don’t have to worry about a faulty lubrication seal once you’ve finished sampling, thanks to Hansen’s unique Oil-Guard and Oil-Lock systems.

6. International support. Because Hansen is a global brand, you can rely on the company to deliver thorough engineering documentation and support before and after purchase of a Hansen gear reducer. With the force of an international brand behind you, downtime is minimized.

7. One-stop shopping. Hansen’s size is also advantageous when it comes to selecting entire pulp and paper mill drive packages. From right-angle gearboxes to roll drives to drive shafts to couplings, Hansen makes it all so you don’t have to waste time matching various manufacturers’ parts.

8. Superior design features. Hansen designers are passionate about creating high-quality gear drive components, and it shows. What other brand would create a seamless lantern-style housing for placing the gear unit within the motor, for instance? Another example of Hansen’s commitment to smart design: housing that smoothly transmits forces from center bore to mounting feet, so as to reduce unnecessary vibration.

Hansen’s decades-long commitment to creating superior gearboxes results in bevel and helical gears with high torque capacity, impressive surface durability and low noise performance.

Finding a good match can affect everything from the ease of installation to the ability of your equipment to function smoothly, with minimal hiccups. Of course, the best way to ensure your replacement Falk gearbox will fit into your current setup is to choose a supplier with the right experience and competitive knowledge to help you find the closest match. As you discuss your needs with your Falk supplier, keep the following considerations in mind:

Physical size.

As succeeding generations of Falk gearboxes become increasingly smaller, fitting a replacement Falk gear reducer into the envelope of an older drive is becoming less of an issue. However, situations still frequently arise in which factories must replace old drives with surplus gear reducers, which may or may not fit properly. Provide your supplier with as much relevant information about the application as possible, including original paperwork and schematics, if available. Consider whether the motor will need to be altered to accommodate the new drive.

Connecting equipment.

In addition to addressing the physical space the new Falk gearbox takes up, it’s important to consider how the unit will interact with connecting machinery. For example, a change in the diameter of a solid connecting shaft will impact couplings and other mounted equipment. Accounting for these changes now will help prevent unpleasant surprises during installation.

Mechanical issues.

Old or surplus gear reducers often feature a more conservative design than newer models, allowing gradual increases in power that newer gear reducers may not be able to tolerate. Double-check that the replacement unit meets all application parameters, regardless of how similar it is to the Falk gearbox it is replacing. Other mechanical considerations include changes in gear ratio (which some applications can absorb but others cannot) and relative shaft rotations.

There are many different types of Falk couplings available, from G couplings to T couplings; selecting the right one depends heavily upon the application at hand as well as how the drive system is arranged. The following is a look at the differences between two basic coupling types: grid couplings and gear couplings.

Gear Couplings (aka G Couplings)

Gear couplings are equipped with gear teeth to transmit torque from one shaft to another. The clearance between the inner and outer rings of teeth gives the gear coupling its flexibility in accommodating misalignments. Falk’s Lifelign gear couplings, also known as G couplings, feature an innovative cost-effective design and come in a variety of configurations, from single-engagement couplings to floating shaft assemblies:

Single engagement.

Single-engagement G couplings typically consist of two hubs (each of which connects to a shaft) joined by a continuous sleeve.

Double engagement.

Double-engagement G couplings offer two flex halves to accommodate minor misalignments.

Spacer couplings.

Spacer G couplings – a double-engagement coupling with a spacer tube in the center – are also available to correct small gaps between connecting parts.

Floating shaft assemblies.

When these gaps are too large for spacer couplings, floating shaft assemblies may be used; these G couplings consist of two single-engagement couplings joined by a connecting shaft.

Grid Couplings (aka T Couplings)

Instead of gear teeth, grid couplings transmit torque using a steel grid running through two slotted hubs. This design provides the high torque capacity of a gear coupling while offering much higher torsional flexibility. Falk’s current line of Steelflex grid couplings, known as T couplings, offer the additional benefit of a “replace-in-place” design, which means a replacement grid can be dropped right into the coupling without having to remove the hubs or realign the shafts.

In the Falk catalog, T couplings have replaced F couplings, the original Steelflex grid design. F couplings are now obsolete but may still be available from our surplus parts inventory.

Falk Gearbox

Provide a sturdy foundation.

Factory conditions are often far from ideal, but when installing a Falk gearbox, it’s critical to at least ensure a solid mounting surface. Not only must the gear drive be properly aligned to the equipment it is moving, but it must be able to stay aligned during operation. When installing a Falk gear reducer on a new concrete foundation, allow the concrete to thoroughly cure before installation. For best results, avoid placing the drive directly on the concrete; rather, use structural steel mounting pads, which provide a level surface for easier installation.

Keep lubrication needs in mind.

If there’s one thing all new and surplus gear reducers have in common, it’s the need to remain adequately lubricated. Make future maintenance easier by mounting the drive above floor level, which facilitates oil changes, and ensuring that the drain plug remains at the lowest point on the Falk gearbox.

Carefully align before bolting down.

Improper alignment of your Falk gear reducer with input and output shafts places undue stress on the bearings and shafts, which causes unnecessary wear and shortens the life of your equipment. Align the gearbox to the machinery being driven first, then bolt in place and align the prime mover to the input shaft. Place connecting devices, such as couplings, as close to the drive housing as possible to minimize overhung load.

Lubricants are crucial for reliable Falk gearbox operation. In complex mechanical systems, lube helps everything flow smoothly. But engineers also see lubrication as a sort of “canary in a coal mine,” in that it shows problems early on. For instance, if you notice lube contamination or an uptick in wear metals, chances are your system is poised to fail. Preventing failure is a top priority for all industrial workers, since downtime means lost money, wasted labor and expensive repairs.

Oil lubrication tests should be regularly conducted for all mechanical applications, regardless of whether they include brand-new or surplus gear reducers. Hydraulic systems, gearboxes and compressors should all have consistent oil samples taken.

The Proper Way to Take an Oil Sample

To avoid tainted samples, store lubrication sample containers in a clean environment where they won’t collect dust. Taking a sample while the system is running will provide the most accurate results. If this is not possible, try to take the sample as soon as possible after the equipment has been turned off.

The location where one takes a lubrication sample also matters. To accurately measure the system’s operating lubrication, take samples downstream of any oil filters. This ensures you are getting a reading of the lubrication conditions for critical components, including surplus gear reducers. There is an ideal sample location for each Falk gearbox and Falk gear reducer. Most surplus gear reducers and other gear-driven systems are designed to lubricate components through a splash method. Typically, a splash system draws from a pool of oil via a “dipper,” which scoops up oil and splashes it to lubricate all nearby parts.

In most circulation/gear systems, the sampling spigot will be located at a high flow point just after filtration. If for some reason the main sampling spigot is unavailable, you can take a sample from the return line or other safe sampling access points.

Once you’ve found your sampling location, it’s time to manually take the sample. First, remove the protective cap from the spigot. Then open the sampling valve, allowing about four ounces of oil to drain. (You will not use this portion in your sample. Draining this part removes any contaminants or stagnant lube that may have collected in the valve.) Here’s the tricky part: Don’t turn the valve off as you switch out the contaminant container for the sampling container. If your testing includes particle counts and you’re using standard sample bottles (instead of “super-clean” sample bottles), discard a couple of oil samples before taking your final selection. Remember to flush your container between samples. For both varieties of sampling bottles, the next step is to replace the sampling top, close the spigot valve and replace its shielding cap.

Recording sampling information is critical for accurate lubrication testing. Each model of Falk gearbox and Falk gear reducer has its own preferred lubrication settings, and taking regular lube data can help you anticipate and even prevent system failures. There are many system variables that can affect a reading. Incorporating noise and vibration data, system temperature and other operating information is crucial for accurate lubrication testing. Such system statistics help one precisely interpret sampling information. If you have any questions about the proper sampling procedure for a certain Falk gear reducer or Falk gearbox, contact the manufacturer.

What to Look For

Once your sample is ready, there are several aspects to consider as symptoms of a good or bad surplus gear reducer:

Viscosity. First, measure viscosity, or a liquid’s resistance to flow. Each gearbox manufacturer provides viscosity suggestions for its products. To minimize system wear, keep your viscosity within the recommended range.

Wear metals. The presence of wear metals is another thing to analyze in your oil sample. Metals show up in lubricant as gears wear down. Falk gearbox and other gearbox systems usually have gears made of lead, copper and iron – nickel, tin and aluminum are also possible, but less widespread. Most systems will show an iron spike upon installation – this sort of sample corresponds to a break-in period for the new gears. Keep sampling, and expect to see a drop in iron levels momentarily. What you want to look for going forward is increased levels in wear metal readings. For example, if you notice an unexpected increase in copper levels in your weekly or monthly sample, it’s possible that a copper component needs realignment or replacement. Again, each manufacturer of new and surplus gear reducers and gearboxes can provide detailed operation and metallurgy information on each of its products.

Regularly testing oil samples is one of the best ways to detect system inefficiencies and contaminants.

Flippable housing. The unique Hansen gear housing design on the UniMiner allows for a variety of different mounting arrangements to fit the needs of the many unique and often inconvenient configurations frequently found in mining operations. This split Hansen gear housing design also makes the unit easy to service.

Precision gearing. The gears within a UniMiner Hansen gearbox are carburized and ground for precision to ensure the unit not only delivers maximum capacity with minimal loss, but operates quietly to boot.

Smooth operation. A smooth-running gearbox is a long-lived gearbox. Hansen gearboxes featuring the UniMiner design use a combination of different bearing types – including spherical, cylindrical and tapered – to ensure smooth operation.

Accessories. To further improve the versatility of UniMiner gearbox, Hansen also provides a selection of accessories for unique applications, including scoop brackets, lantern housings and belt drive arrangements.