Pulley Misalignment
Pulley misalignment is a common problem in belt-driven fans that can cause significant damage to the fan and its components. Belt-driven fans are widely used in a variety of industrial and commercial applications, including HVAC systems, ventilation systems, and air-handling units. They rely on a system of pulleys and belts to transfer power from the motor to the fan blades. If the pulleys are not aligned correctly the belt can wear prematurely, the bearings can fail, and the fan can vibrate excessively, leading to reduced efficiency, increasing energy consumption, and ultimately, equipment failure.
The most common type of pulley misalignment is known as angular misalignment. This occurs when the axes of the two pulleys are not parallel, causing the belt to run at an angle. Angular misalignment can also be caused by several factors, including improper installation, worn or damaged pulleys, or a misaligned motor.
Another type of pully misalignment is called parallel misalignment. This occurs when the pulleys are parallel, but the centerlines of the pulleys are not in the same plane. Parallel misalignment can also be caused by improper installation or worn or damaged pulleys.
The effects of pulley misalignment on belt-driven fans can be severe. The belt can wear unevenly and develop cracks, which can lead to belt failure. A worn or damaged belt can slip on the pulleys, causing excessive heat, which can damage the bearings and other components. Excessive vibration can also occur, which can damage the motor and the fan blades. In severe cases, the fan can come loose from its mountings, causing safety hazards and significant damage to the surrounding equipment and personnel.
Below is data taken by CTC Educational Partner Ally Attia with MDI. This data shows a phenomenon seen in pulley misalignment: Vibration data of Motor may be high at Fan 1x frequency, and vibration data of Fan may be high at Motor 1x frequency.
The following snapshot shows a FAN Drive end has a high 1x of opposite component (Motor):
