Direct Drive And Belt Driven Fans

In a direct drive configuration the fan motor that controls the movement of the fan blades is connected either to a shaft or fan axle.

Direct drive and belt driven fans. Thus the fan blades will rotate at the same speed as the motor rotates. Direct drive fans should be designed for acceptable bearing life. When compared to belt drive fans which require belts sheaves and bushings direct drive is just plain simpler and maintenance folks tend to lean toward direct drive for daily maintenance. You have a fan a motor and maybe a coupling.

On a direct drive fan as implied by the name the fan propeller is connected directly to the shaft of the motor. More often than not the maintenance cost of this kind of fan is also comparatively lower. Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss. With the growing acceptance and affordability of vfd motor controllers direct drive fans are increasingly finding their way into mainstream industrial fan applications.

The two bearings on direct drive fan motors which are 7 horsepower and larger are typically regreaseable. The second pulley is connected to a shaft that drives the fan propeller. While both belt and direct drive fans have been around for a long time the mainstay fan for most industrial fan applications under 250 hp has been the belt drive fan. Belt drive fans have two additional bearings.

Unlike belt driven fans there s less energy loss because there s a reduced amount of friction as the fan operates. Greater efficiency is the biggest pro of direct drive fan configurations. Direct drive fans require fewer parts and thus usually less maintenance. This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating.