The main structural components of the fan are impeller, casing, air inlet, bracket, motor, pulley, coupling, muffler, transmission parts (bearings), etc. The unpowered fan uses the air heat convection caused by the natural wind and the indoor and outdoor temperature difference to drive the turbine to rotate so as to use the centrifugal force and negative pressure effect to exhaust the indoor fresh hot air.

风机关系到系统的输配能耗，是建筑节能非常关键的部分。根据国家空调设备质量监督检验多年风机检测表明很多风机在额定工况下都存在问题，因此需要严格按照产品标准要求生产和制造风机。风机刚开始工作时轴承部位的振动很小，但是随着运转时间的加长。

Fan is related to the energy consumption of transmission and distribution of the system, and is a very important part of building energy saving. According to the national air conditioning equipment quality supervision and Inspection Center for many years, fan testing shows that many fans have problems under rated conditions, so it is necessary to produce and manufacture fans in strict accordance with product standards. At the beginning of the fan, the vibration of the bearing is very small, but it increases with the running time.

风机内粉尘会不均匀的附着在叶轮上，逐渐破坏风机的动平衡，使轴承振动逐渐加大，一旦振动达到风机允许的值11mm/s时（用振幅值表示的允许值如下），风机必须停机修理（清除粉尘堆积，重做动平衡）。因为这时已是非常危险的，用户千万不可强行使用。在风机振动接近危险值时，有测振仪表的会报警。

The dust in the fan will adhere to the impeller unevenly, and gradually destroy the dynamic balance of the fan, so that the bearing vibration will gradually increase. Once the vibration reaches the maximum value of 11mm / s allowed by the fan (the maximum allowable value expressed by the amplitude value is as follows), the fan must be shut down for repair (remove the dust accumulation, and do the dynamic balance again). 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.

风机的轴承温度正常时为≤70℃，如果一旦升高到70℃，有电控的应（会）报警。此时应查找原因，首先检查冷却水是否正常？轴承油位是否正常？如果一时找不到原因，轴承温度迅速上升到90℃，有电控的应（会）再次发出报警、停车信号，风机开车、停车或运转过程中，如发现不正常现象应立即进行检查，检查发现的小故障应及时查明原因设法消除。

When the bearing temperature of the fan is normal, it is ≤ 70 ℃. If it rises to 70 ℃, the fan with electric control shall (will) give an alarm. At this time, the reason should be found out. First, check whether the cooling water is normal? Is the bearing oil level normal? If the cause cannot be found for a while, the bearing temperature will rise rapidly to 90 ℃. If there is electric control, the alarm and stop signal shall be sent again. In the process of fan start-up, stop or operation, if abnormal phenomenon is found, it shall be checked immediately, and the small fault found in the check shall be found out in time to eliminate the cause.