3. When installing Type C and Type B, ensure that the two pulley positions are on the same plane, and the flatness tolerance is 0.5mm. 4. When installing Type D, use a dial indicator and feeler gauge to measure the coaxiality of the fan spindle and motor spindle and the parallelism of both ends of the coupling. The coaxiality tolerance of two shafts is 0.2mm, the parallelism tolerance of both ends of the coupling is 0.2mm, and the spacing between two planes of the coupling is 5 to 8mm. 5. After the fan is installed, move the rotor with hand or lever to check whether it is too tight or collided. The test run can be carried out without overtightening or collision. 6. After the motor is installed, the belt pulley or coupling guard shall be installed. If the air inlet is not connected to the air inlet pipe, the guard net or other safety devices (provided by the user) shall also be provided. 7. Other parts shall be installed according to the corresponding positions in the drawing. 8. Add N46 (ISO VG46, 30) in summer and N32 (ISO VG32, 20) in winter. The oil level should be at 1/2 of the oil window.

（2） Precautions for normal operation of fan 1. If the flow is found to be too large, which does not meet the operating requirements, or less flow is required in a short time, the throttling device can be used to adjust to meet the operating requirements. 2. The sensitivity of thermometer and oil pointer shall be checked regularly. 3. In case of any abnormal phenomenon during the start-up, shutdown or operation of the fan, it shall be checked in time. 4. For minor faults found in the inspection, find out the causes in time and try to eliminate or deal with them. If minor faults cannot be eliminated or major faults are found, repair them immediately. 5. In addition to replacing the lubricating oil during each maintenance, the lubricating oil shall also be replaced regularly. Observe the oil level at ordinary times and replenish lubricating oil in time.

Gas compression and gas transmission machinery is a machine that converts rotating mechanical energy into gas pressure energy and kinetic energy and transports gas. The main structural components of the fan are impeller, casing, air inlet, support, motor, pulley, coupling, silencer, transmission parts (bearings), etc. large Centrifugal fan The unpowered fan uses the air thermal convection caused by the natural wind force and the indoor and outdoor temperature difference to drive the turbine to rotate, thus using the centrifugal force and negative pressure effect to exhaust the indoor stale hot air. Southwest Guizhou Centrifugal fan manufactor The fan is related to the transmission and distribution energy consumption of the system, and is a very critical part of building energy conservation. According to the fan inspection conducted by the National Air Conditioning Equipment Quality Supervision and Inspection Center for many years, many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. large Centrifugal fan At the beginning of the fan operation, the vibration of the bearing is very small, but with the extension of the operating time, the dust in the fan will be unevenly attached to the impeller, gradually destroying the dynamic balance of the fan, making the bearing vibration gradually increase. Once the vibration reaches the maximum allowable value of 11mm/s of the fan (the maximum allowable value expressed by the amplitude value is as follows), The fan must be shut down for repair (dust accumulation shall be removed and dynamic balance shall be redone). Because it is very dangerous at this time, users must not use it forcibly. When the fan vibration is close to the dangerous value, the vibration measuring instrument will give an alarm.

（3） The main faults and causes of the fan may occur during the operation of the fan. For the faults generated, the causes must be quickly identified and solved in time to prevent accidents. Faults in the Operation of 4-72-12 Centrifugal Fan and the Causes Table Fault Name Causes Severe Vibration of Bearing Box 1. The fan shaft is different from the motor shaft, and the coupling is installed askew. 2. The casing or air inlet rubs with the impeller. 3. The foundation stiffness is not enough or firm. 4. Impeller rivet is loose or wheel disc is deformed. 5. The impeller shaft disk and shaft are loose, and the coupling bolt is movable. 6. The connection between casing and bracket, bearing box and bracket, bearing box and seat is loose. 7. The air inlet and outlet pipes of the fan are poorly installed, causing vibration. 8. The rotor is unbalanced. Bearing temperature rise is too high 1. The bearing box vibrates violently. 2. The lubricating grease is poor in quality, deteriorated or overfilled, or contains dust, sand, dirt and other impurities. 3. The tightening force of connecting bolts of bearing cover seat is too large or too small. 4. The shaft and rolling bearing are installed askew, and the front and rear bearings are not concentric. 5. The rolling bearing is damaged. The motor current is too high and the temperature rise is too high. 1. The throttle valve in the air inlet pipe is not closed tightly when driving. 2. The flow exceeds the specified value, or the air duct leaks. 3. The gas density conveyed by the fan is too high. 4. The input voltage of the motor is too low or the power supply is cut off individually. 5. The coupling is improperly connected, the leather ring is too tight or the gap is uneven. 6. Affected by the violent vibration of the bearing box. 7. Affected by deterioration or failure of parallel fans. When the belt slides down, the two pulleys are not in the same plane with each other. Belt runout The distance between two pulleys is too close or the belt is too long.