Belt Drive Fan System
OVERVIEW Among power transmission options, the belt drive’s simple design and manufacturability make it a cost-effective alternative. SPX Cooling Technologies offers belt drives in many cooling tower models. New belt drives produce about 95 percent efficiency. Beyond its low initial cost, the belt drive’s exposed components require frequent maintenance, so higher operating cost can be expected.


In a belt-driven cooling tower, the motor and motor sheave supplies power to the belt, which is attached to the fan shaft by a sheave. A bearing and bushing hold it all together. This technology offers smooth and effective transmission of power between shafts, even if they are at a considerable distance. Regular belt lubrication and tensioning are required to ensure proper power transmission and cooling tower operation. Over time, as the belts stretch and wear, percent efficiency can dip to the low 90s or even lower, calling for more frequent replacement – once a year, typically. Maintenance professionals should conduct a monthly inspection to check proper belt tension and alignment, adequate lubrication, and signs of wear.

Belt drives are often employed in cooling towers with lower horsepower requirements. Like a gear drive, the belt drive does not require a variable frequency drive (VFD). The Marley Geareducer® gear drive offers a more efficient alternative that provides energy, installation and maintenance cost savings.


Genuine Marley OEM parts are precision-engineered to provide you with a reliable product. While other suppliers may offer parts at an initial savings, you risk lowering performance — and losing FM and CTI ratings. Marley OEM parts provide the durability you can trust because we design and manufacture them exclusively for cooling towers.

With plant operation relying on your cooling tower performance, it’s important to select the parts that are among the highest quality available — Marley OEM parts.

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Marley® Cooling Tower Gear Drives Vs. Belt Drives
  • Most suitable for lower hp applications

  • Operates at about 95% efficiency initially

  • Lower first cost

  • Frequent maintenance recommended

  • No VFD required


Marley Cooling Tower Parts