Gear reducers
The gear reducer turns a horizontal motor shaft into the vertical fan shaft, and it is the most expensive single component in the mechanical train. It is also the one most often written off when it could have been rebuilt.
Understanding the component
A cooling tower gear reducer is a right-angle drive that takes power from the motor through a drive shaft and delivers it to the fan at the correct speed. Single and double reduction units are both common, depending on fan diameter and motor speed.
It works in the worst environment on the plant: saturated air, chemically treated water, condensation inside the housing whenever the fan stops, and a fan that applies a fluctuating overhung load for its entire service life. Design features that matter are therefore mundane ones: a single-piece housing with no split-line seal to leak, dual lipped shaft seals to keep contamination out, and oil circulation that works in both directions of rotation because the fan may be reversed for de-icing.
Amarillo right-angle fan drive. We supply and rebuild the major gear lines.
We supply components for cooling towers from every manufacturer, including towers whose original makers no longer exist. If it is on your tower, we can identify it.
What actually goes wrong
These are the failures we find in the field, roughly in order of how often we find them. If you recognize one, we can usually tell you what to check next over the phone.
| Failure | What it means |
|---|---|
| Water in the oil | The most common finding and the most treatable. Oil that looks like coffee with milk means a seal or a breather is admitting moisture. Left alone it destroys bearings and etches gear teeth. |
| Bearing noise or heat | A gearbox running hotter than its neighbors, or making a noise it did not make last month, is giving you the cheapest warning you will get. |
| Seal leakage | Oil weeping from the input or output shaft. Lose enough oil and the bearings run dry long before anyone notices the level. |
| Housing corrosion | Corrosion through the housing or its mounting is what genuinely condemns a unit. If the housing is sound, almost everything inside it is renewable. |
| Damage from a coupling failure | A failed drive shaft or disc pack can wreck the input shaft and bearings. This is why coupling inspection is worth doing. |
Manufacturers and product lines
We are independent, so the recommendation follows your tower, your water and your duty rather than a single manufacturer's catalog.
Amarillo Gear Company
The "A" Series right-angle drives are designed as direct replacements for the Marley Cooling Tower line of right-angle drives: mounting dimensions, input shaft diameters and keyways all correspond, so the swap does not require modification. Design features and ratings meet or exceed AGMA and CTI standards.
Sumitomo
The Paramax line: carburized and ground helical and spiral bevel gearing, cast iron housings and a modular assembly configuration. Also built to meet or exceed AGMA and CTI requirements.
Marley
Geareducer units and parts for towers where you would rather stay with the original line.
Other major lines
Hansen, Philadelphia and others as the nameplate requires.
Names you may find on the nameplate
Including lines that are no longer current. Many of the towers we work on are thirty to fifty years old, and identifying the modern equivalent of a discontinued component is part of the job rather than an obstacle to it.
- Marley Geareducer
- Amarillo
- Sumitomo Paramax
- Hansen
- Philadelphia
What we would tell you on the phone
Rebuild before you replace.
Where the housing and mounting are serviceable we can strip and rebuild the unit (bearings, seals, gears and shafts) and on many towers we can do it in place. On a rooftop or an awkward industrial deck that avoids a crane, a lift plan and the disruption both entail, which is regularly a larger cost than the gearbox itself.
Send us the nameplate.
Gear ratio, service factor, fan speed and mounting dimensions all have to match. A photograph of the nameplate and of the mounting is worth more than any description, and it lets us confirm the correct replacement rather than guessing from a model number that may have been superseded twice.
Realignment is part of the job.
A new or rebuilt reducer that is not aligned to the motor within tolerance will destroy the next coupling. We align and dynamically balance on reassembly.
Usually replaced or inspected at the same time
Drive shafts & couplings
Composite and steel drive shafts with flexible disc couplings: Addax, Amarillo, Rexnord Thomas and TB Wood's.
View componentMotors
Cooling tower duty fan motors: severe duty and premium efficiency, single and two-speed, any horsepower.
View componentFans
Fiberglass and aluminum fan assemblies, blades and hubs: Hudson, Amarillo Chittom, Moore and Cofimco.
View componentVibration switches
Mechanical and electronic vibration cut-outs: Murphy VS2, PMC/BETA and Metrix. The cheapest protection a fan drive can have.
View componentSend us the nameplate and we will identify it
The fastest route to a correct quote is a photograph of the nameplate and of the component in place. Model numbers get superseded and drawings go missing; photographs do not lie.
- Phone
- (713) 643-0691
- Shop & office
-
3811 Cedar Blvd Ste A
Baytown, TX 77523