Pulleys are mechanical parts of air cooler, which are usually made of rigid aluminum. They are responsible for transferring force from electromotor to fan. Typical air coolers use two sets of pulleys; small pulley on the shaft of motor and large pulley on the shaft of the fan.
The layout of the two pulley ensures that they are positioned on one plane; otherwise, the belt will be worn. The pulleys are fixed on the shaft with Allen key. To avoid stripped pulley the pulleys should be fixed in their position.
The pulley that rotates the fan are called “Blower Pulley”. The pulley is named based on inner diameter and based on diameter of the shaft, pulleys are produced for shafts 19 and 20.
An effective factor in improvement of performance of air cooler is size of motor and blower pulley. The following table lists standards of motor and blower pulleys for different sizes of air cooler.
| Air cooler size | size of motor pulley | size of blower pulley |
|---|---|---|
| 2800 | 65 | 114 |
| 3000و3500 | 65 | 155 |
| 70 | ||
| 75 | ||
| 4000و4500و5000 | 80 | 255 |
| 85 | ||
| 6000 | 89 | 308 |
Air cooler capacity increases with increase of motor pulley size or decrease of blower pulley size; however, power of electromotor is another factor effective on performance. Unmatched motor, motor pulley, and blower pulley may cause serious damages to the motor. Therefore, before replacing pulleys please consult with a technician.