Xin Feng Classroom | Ventilator Series: Transmission Methods for Ventilators

01 

Direct Drive (Type A)

       Type A: Direct motor coupling, where the fan impeller is mounted directly onto the motor shaft extension, is the most commonly used configuration in our fans.     This method offers easy installation, fewer components, and lower cost; it avoids power losses associated with indirect drive. However, the impeller speed is directly determined by the motor speed and is fixed. Suitable for small ventilators, it features a compact structure and small body. Suitable for conveying media with temperatures below 80°C.

02

Belt Drive (Type B, Type C, Type E)

The motor's power is transmitted to the driven shaft via a belt.    

 Type B: Characterized by the driven shaft being supported by two bearings, with one end unsupported. The pulley is mounted between the two bearings, meaning both ends of the pulley are supported. The impeller is mounted on the unsupported end of the driven shaft, meaning only one end of the impeller is supported. This configuration is rarely used due to the difficulty of removing the pulley and is generally reserved for large fans, such as those sized 14 or larger. It is suitable for medium-sized and larger fans with variable speed capabilities.     

Type C: Characterized by the driven shaft being supported by bearings at both ends, with both ends unsupported. The impeller and pulley are each suspended at one end, meaning only one end of each component is supported. Among belt drive configurations, this type is most common due to the relative ease of pulley removal. Suitable for medium-sized and larger fans with variable speeds, where pulley removal is relatively convenient.     

Type E: Characterized by the drive shaft being supported by two bearings with one end unsupported. The impeller is mounted between the two bearings, meaning both ends of the impeller are supported; the pulley is mounted on the unsupported end of the drive shaft, meaning only one end of the pulley is supported. The advantage of this installation method is relatively balanced operation. It is mostly used on double-suction, variable-speed cabinet-type centrifugal fans.

Belt drives are most commonly used in centrifugal fans because they allow the rotational speed of the impeller to be adjusted by changing the size of the pulleys.

03 

Coupling Drive (Type D, Type F)        

 Type D: The impeller is suspended, meaning it is supported at only one end.     

Type F: The impeller is mounted between two bearings, meaning it is supported at both ends.

04

Overview Diagram of Transmission Methods