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amarillo gears

Amarillo Series Fan Drive - Single & Double Reduction

Full Catalog: New AG RA Gear Drive Cooling


Amarillo Gear Company’s cooling tower drives have a long history of quality workmanship and reliability. An example of our commitment to excellence is the availability of complete noise and vibration testing, with all data taken under full horsepower loading up to 500 hp.

Design features and ratings are in accordance with or exceed the minimum requirements of AGMA (American Gear Manufacturers Association) and CTI (Cooling Technology Institute) standards.


Housing and Castings

Castings are rigidly designed and constructed to absorb internal and external loads with minimum deflection. Gear case and cover are manufactured to assure permanent alignment of bearings and gears under load. The sloped floor of the gear case adds rigidity and permits complete drainage of oil. All casting materials are gray iron for effective damping of noise and vibration. All mating castings are sealed using “formed-in-place” gasket material which eliminates “weeping” associated with fiber-type gaskets. Gear cases are pre-drilled with pilot holes to assist in installation of dowel pins.



Spiral Bevel Gears

Designed and manufactured by Amarillo Gear Company for fan drive service, all spiral bevel gears are precision machined from high grade 8620 alloy steel, case hardened, and lapped in pairs for quiet operation.

Helical Gears

Helical gears are designed specifically for fan drive service and are precision machined from high grade 4320 alloy steel, case hardened and precision ground to provide low-noise, low vibration operation.



All bearings are roller type, provided by major manufacturers. The fan shaft thrust bearing is designed to carry all loads imposed by the fan while maintaining 100,000 hours L10 life. All bearings are sized to meet or exceed the minimum life requirements of AGMA and CTI.


Quiet Operation

Quiet operation of the Amarillo Gear Drive is achieved through careful design and controlled manufacturing methods of components. Our engineers understand all of the many parameters that affect gear noise and have applied the latest research to the design and manufacture of all components. Parameters that reduce gear noise are controlled during design, manufacturing, and assembly to ensure quiet operation. Input and output shafts are permanently aligned in rigid housings guaranteeing alignment of gears under load. Test results collected in our state-of-the–art test facility support that our sound levels are the lowest available in the industry.


Shaft Seals

Both the input and output shaft openings have dual spring-loaded, single-lip seals to keep outside contamination from entering the gearbox. Plus, the output shaft has a labyrinth-type plate directly mounted to the shaft to triple protect the gearbox from contamination.



Oversized slinger on the input shaft provides adequate lubrication in either direction or at half speed operation. Continuous circulation of the oil to all bearings is assured by location of channels and baffles. Double reduction units can also be supplied with positive displacement bi-directional oil pump and oil distribution system to all bearings. This pump is driven from the intermediate shaft and provides a redundant lubrication system for extreme reliability. A permanently mounted oil sight glass is included on each gear drive.


Service Openings

The large inspection plate cover is easily removed for periodic inspections. Ports for oil fill, oil drain, and venting are tapped and located for installation of remote oil service piping when desired.


Optional Features

Special output shaft lengths, backstops (anti-windmilling), oil level switches, oil heaters & thermostats, oil temperature switches, spot-face/drill & tap for vibration transducers, “Low Speed” option and other accessory items are available on special order.


Low Speed Operation

For operation when motor speeds are less than 450 rpm, single reduction fan drives require Amarillo Gear’s exclusive “Low Speed” option, and double reduction fan drives require a mechanical oil pump for proper lubrication. The addition of these options allows operation with no minimum input speed restrictions.

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