Type A: cantilever type, bearingless, the centrifugal fan impeller of the boiler is directly installed on the motor shaft, and the speed of the centrifugal fan of the industrial boiler is the same as that of the motor. It is suitable for small fans with compact structure and small body.

b型:悬臂式，带传动结构，带轮安装在两个轴承座之间。适用于中型以上转速可变的风扇。

Type B: cantilever type, belt transmission structure, pulley is installed between two bearing seats. It is suitable for medium-sized and above fans with variable speed.

c型:悬臂式，带传动结构，带轮安装在两个轴承座的外侧。适用于中型以上转速可变的锅炉离心风扇，带轮拆卸方便。

Type C: cantilever type, belt transmission structure, and the pulley is installed on the outside of the two bearing seats. It is suitable for the centrifugal fan of medium-sized and above boilers with variable speed, and the pulley can be easily disassembled.

d型:悬臂型，采用联轴器连接风扇和电机主轴的传动结构，联轴器安装在两个轴承座的外侧，风扇的转速与电机相同。适用于中型以上锅炉离心风扇。

D type: cantilever type, with the transmission structure of coupling connecting the fan and motor spindle, the coupling is installed on the outside of the two bearing seats, and the speed of the fan is the same as that of the motor. It is suitable for centrifugal fans of boilers above medium size.

E型:带传动结构，两个支承轴承分别安装在外壳的两侧，即叶轮放置在两个支承轴承的中间，为双支承式，带轮安装在离心风机的一侧。适用于双吸或大型单吸，转速可变的离心风机，具有运行平衡的优点。

E type: belt transmission structure, two supporting bearings are installed on both sides of the shell, that is, the impeller is placed in the middle of the two supporting bearings, which is double supporting type, and the pulley is installed on one side of the centrifugal fan. Suitable for double suction or large single suction, variable speed centrifugal fan, with the advantages of balanced operation.

F型:采用联轴器连接锅炉风机和电机主轴的传动结构。两个支承轴承分别安装在外壳的两侧，为双支承式，联轴器安装在一个轴承座的外侧 适用于双吸或大型单吸，转速与电机转速相同的锅炉离心风机，具有运行稳定的优点。

F type: it is a transmission structure that uses coupling to connect boiler fan and motor spindle. Two support bearings are installed on both sides of the shell, which are double support type. The coupling is installed on the outside of a bearing seat. It is suitable for double suction or large single suction boiler centrifugal fan with the same speed as the motor speed, and has the advantages of stable operation.

说完了工作原理，下面就来谈谈离心式通风机的维护常识了，

Having said the working principle, let's talk about the maintenance common sense of centrifugal fan,

1.风机必须有专人操作和维护保养。

1. The fan must be operated and maintained by a specially assigned person.

风扇不能带病运转。

The fan doesn't work with problems.

定期清除风机内部的灰尘，尤其是叶轮上的灰尘、污物及其它杂质，以防止锈蚀和失衡。

Regularly remove the dust inside the fan, especially the dust, dirt and other impurities on the impeller to prevent corrosion and imbalance.

2.风机维护必须强调首先切断电源。

2. For fan maintenance, it must be emphasized to cut off the power supply first.

3.定期检查温度计和油标的灵敏性。

3. Regularly check the sensitivity of thermometer and oil pointer.

4、正常情况下3-6月更换一次润滑油，但每次拆卸后应更换润滑油。

4. Under normal circumstances, the lubricating oil should be changed once in March to June, but the lubricating oil should be changed after each disassembly.