Causes of Frequent Failure in Self-aligning Bearings of Fume Hood Centrifugal Fans and Commissioning Methods

Causes of Frequent Failure in Self-aligning Bearings of Fume Hood Centrifugal Fans and Commissioning Methods

A fume hood centrifugal fan consists of two main components. First, the fan unit itself includes the housing, inlet, impeller, and bearing shaft. The second part consists of auxiliary equipment such as the motor, silencer, and exhaust system. Bearings are indispensable components in the motor rotor assembly and generator assembly of fume hood centrifugal fans. Generator units typically contain various types and multiple bearings. Especially under harsh operating conditions, bearings are key to ensuring the normal and stable operation of fume hood centrifugal fans. The self-aligning bearings introduced today are located inside the gearbox; they are critical output components of the fan but are also prone to damage. Damage is usually caused by improper installation or operation. During installation, pay close attention to selection issues. If the wrong type is selected, the self-aligning bearings will not only wear out but may also damage other components inside the housing during commissioning. Specific items include on-site measurement data, motor marking data, calculated data, and system additional resistance. On-site test data is particularly important and requires high precision. The first set of test data includes 11 items such as air pressure (87,800 Pa), dry-bulb temperature at the inlet of the fume hood centrifugal fan (28.74°C), wet-bulb temperature (16.45°C), fan speed (1,340 r/min), and ventilation area (0.734 m²). The motor nameplate data includes rated power, the number of phases in the motor stator windings, rated voltage, and speed.