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Falk Concentric Shaft Reducers – Uses and Service Factors

Concentric shaft reducers, also known as inline gear reducers, are unique in that they facilitate installation over a common centerline between the high-speed input shaft and the low-speed output shaft. Concentric shaft reducers thereby solve space restriction and alignment problems of right angle and parallel shaft reducers. Additional advantages of inline gear reducers include their flexible mounting options and consistent performance in high torque applications. In addition to slowing output speed, concentric gear reducers may also increase available torque.

Various industries use Falk concentric shaft reducers for high torque applications. As an example, in mining, inline reducers may assist in conveying ore from the excavation site to a processing facility. Because such conveyer belts may stretch for miles, they require reducers that continuously deliver high-torque power for multiple hours, and in dirty conditions. Falk concentric shaft reducers are trusted to deliver reliable performance in mining and other challenging environments. Concentric shaft reducers are often used in conveyor systems, mixers, fans, and fill systems. It’s not uncommon to find inline gear reducers in food manufacturing, forestry and pulp mills, and aggregate production.

Here are a few more benefits that inline gear reducers offer:

• Low noise levels
High efficiency
• High reduction capacity

It’s important to remember that any gear drive can only perform according to the manufacturer’s specifications. If the proper research isn’t done, a gear drive will not be compatible with the surrounding components. This becomes especially problematic when changing production routines. For instance, a gear reducer may reliably work with a packaging line for years, until management decides to run the line twice as fast with the same load. New operation requirements demand precise calculation of gear ratio, thermal horsepower ratings, and more. A small error in engineering can result in rapid reducer deterioration and failure.

As an example, consider the above packaging line scenario highlighted in a Machine Design article. The plant engineer used a 1:1.5-ratio V-belt drive to increase output speed by 50%. However, he forgot to consider increased thermal horsepower, and as a result the speed reducer exceeded thermal horsepower ratings, breaking down lubrication, and causing pitted, worn gears, as well as the unnecessary replacement of a reducer.

Two of the most important factors in gear selection are service factors and load classifications. Service factor describes a motor’s periodical overload capacity. The American Gear Manufacturers Association publishes standards for gear reducers. Included in this reference are service factor guidelines. This calculation is key because the service factor determines the proper operating loads to avoid motor damage. Longer periods of service also raise the service factor. Frequent starts and stops also lift service factors, as do higher ratios of rotational inertia.

Load classifications are categories determined by service factors. The AGMA defines three load classifications, according to shock loads:
1. Uniform loads (U) – Operation is consistent with no sudden acceleration or deceleration.
2. Moderate Shock loads (M) – Sudden starts and stops occur at moderate intensities.
3. Heavy Shock loads (H) – Quick acceleration and deceleration is common, with high shock values.

Service factors and load classifications are commonly used variables which engineers rely on to determine reducer ratings for horsepower, frame size, and other key specs. To account for unusual operating circumstances, the designer must multiply the torque/power value by the appropriate service factor. Choosing the correct reducer greatly reduces drive costs by minimizing downtime, boosting productivity, and decreasing the need for repair/replacement.

For more details on selecting the correct gear reducer for your plant, give us a call. We know Falk speed reducers inside and out. Our technicians have decades of experience in troubleshooting and rebuilding reducers. They can help you choose the best reducer for your needs.

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