Marley Cooling Tower Drive Systems
The drive system carries power from the motor to the cooling tower fan. As the official distributor of Marley cooling towers in Singapore, Stolz Engineering supplies genuine Marley cooling tower gearboxes, couplings, driveshafts, belt drives and direct drive fan motors, and can fit them through our Parts Replacement service.
Gear, Belt or Direct Drive?
Marley cooling towers drive the fan in one of three ways. A gear drive uses a Geareducer® gearbox, connected to the motor by a driveshaft or coupling. A belt drive uses belts and pulleys. A direct drive uses a motor connected straight to the fan. The Geareducer is standard on Marley NC cooling towers, while belt drives and direct drive motors are also available as replacement options.
Gear Drive Systems
A Geareducer reduces the motor's speed to the speed the fan needs. Marley Geareducers are designed specifically for cooling tower service, and each one is load-tested at the factory before shipping.
Geareducer® – Single Reduction
Marley's single reduction cooling tower gearbox, backed by more than 100,000 Geareducer units built for cooling tower service.
Geareducer® – Double Reduction
Built for cooling towers in large industrial and power plant applications, with two-stage gearing and bearings rated for a minimum of 100,000 hours of service life.
Geareducer® – M Series
A direct replacement for Amarillo gear drives in non-Marley cooling towers used in power and industrial plants. Its matching footprint means the fan hub, driveshaft and adaptor plate can usually stay in place.
Couplings and Driveshafts
Couplings and driveshafts carry power from the motor to the Geareducer. Because they run inside the tower at close to full motor speed, they need to resist corrosion and stay well balanced to avoid vibration and wear.
Driveshaft – Flex Coupling (Comp-DS)
A carbon-fibre driveshaft with stainless steel hubs and flexible elements that make installation and alignment easier. Suits fans up to 10 m in diameter and motors up to 300 hp, in lengths up to 4.6 m.
SofTork™ Coupling
A flexible, tire-type close coupling for cooling towers. It dampens vibration, cushions shock loads in variable frequency drive applications, and tolerates misalignment.
Driveshaft – Flex Bushing
A full-floating driveshaft with non-lubricated flexible couplings at each end, available with a stainless steel or carbon-fibre tube. Factory balanced, in lengths up to 4.6 m.
Belt and Direct Drives
Couplings and driveshafts carry power from the motor to the Geareducer. Because they run inside the tower at close to full motor speed, they need to resist corrosion and stay well balanced to avoid vibration and wear.
Belt Drive Fan System
A simple, lower-cost option, best suited to cooling towers with lower horsepower requirements. It doesn't need a variable frequency drive (VFD), but belt tension and alignment need regular checks.
Permanent Magnet Direct Drive Fan Motor
A permanent magnet motor drives the fan directly, removing the gearbox, driveshaft and couplings, along with their alignment work. Available on most Marley NC cooling towers. It has a higher first cost and must run with a VFD.
Frequently Asked Questions
What does a cooling tower gearbox do?
A cooling tower gearbox, such as the Marley Geareducer, reduces the motor's speed to the slower speed the fan needs to move air efficiently through the tower.
Should I choose a gear drive, belt drive or direct drive?
It depends on the tower and how you run it. Belt drives have a lower first cost but need more frequent maintenance. Gear drives are standard on Marley NC cooling towers. Direct drive motors need minimal maintenance but cost more upfront and require a VFD. Our team can recommend the right option for your tower.
Can you replace the gearbox on my existing Marley cooling tower?
Yes. Send us your cooling tower model and serial number, and we'll identify the correct Marley Geareducer. We can also fit it through our Parts Replacement service.
Need a Replacement Drive Part?
Send us your cooling tower model and serial number, and our team will recommend the right Marley part