In line with this global concern, WEG has continually searched for new developments of high efficiency products to offer customer solutions providing quick return on their investments through energy savings.

For increased reliability and economy in cooling tower applications, WEG developed - the W22 Cooling Tower Direct Drive System that eliminates the gearbox of the conventional cooling tower, allowing reduction of mechanical losses with increased operational flexibility and consequent increase of the system efficiency level.

Understanding the Direct Drive System application:

In large manufacturing processes that require a cooling system, water is used as a heat conductor. The water transfers the heat into the environment through the cooling towers. The airflow through the tower to aid heat transfer is forced through the water “spray” by a large fan.

The fan is powered by a system consisting of an electric motor and a gearbox, the system provides torque and speed suitable to the fan operation.

In recent years, WEG has developed a motor suitable to deliver torque and speed without using the gear reduction system. (Gearless)

This motor was designed by using permanent magnets in the rotor, which ensures high efficiency levels and high torque, even at low speed controlled by a Variable frequency Drive (VFD). The motor speed control results in a great economic advantage to the system since it allows airflow control to match the requirements of the application during variations in the process needs and environmental changes. Reduction in the power required by the application is exponential with the speed of the fan, which can save significant energy over a fix speed system.

As stated by engineer Alex Sandro Barbosa Passos – WEG Product Development and Application Department – “Since the W22 Cooling Tower Direct Drive System does not require a reduction system, this eliminates contamination of the Tower’s water by gear oil leaks and brings advantages to the system, such as increased efficiency with the controlled air flow, less maintenance downtime and noise level reduction.” “Other benefit offered by the Direct Drive System not less important, is the safety system which allows set up of the VFD with overcurrent protection that guarantees complete motor shutdown in case of an emergency.”

The conventional cooling tower system can experience major maintenance issues due to gearbox failures, contamination, oil leaks, mechanical misalignment and excessive vibration. These issues are eliminated with the Direct Drive solution.

Cooling Tower Direct Drive System Benefits:

- Greater energy savings

- Coupling/ mechanical drive train is not required

- Increased safety and reliability

- Lower noise

- Low maintenance requirements

- Reduced mechanical losses since gearbox and drive shaft are not required

Conventional System:

New System: