Centrifugal fan is essentially a variable flow and constant pressure device. When the rotating speed is fixed, the theoretical curve of pressure flow of centrifugal fan should be a straight line. The actual characteristic curve is bent due to internal loss. The change of inlet temperature or density has a great influence on the pressure produced by centrifugal fan. For a given inlet, the pressure is minimum at the maximum inlet temperature (minimum air density).

　　对于给定的压力和流量特性曲线，有一个功率和流量特性曲线。当风机以恒定速度运行时，给定流量所需的功率随着进口温度的降低而增大。离心风机驱动部分的磨损是常见的设备问题，包括抽风机的轴承位置、轴承腔的磨损、风机轴的轴承位置等。

　　For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the fan operates at a constant speed, the power required for a given flow increases with the decrease of the inlet temperature. The wear of the driving part of the centrifugal fan is a common equipment problem, including the bearing position of the suction fan, the wear of the bearing cavity, the bearing position of the fan shaft, etc.

　　鉴于上述离心风扇的问题,传统的维修方法包括堆焊、热喷涂、电动刷牙,等等,但都有一定的缺点:由高温引起的热应力的补焊不能完全,而且很容易形成物质损失,导致零件的弯曲或断裂;而刷镀则受镀层厚度限制，容易剥落，而以上两种方法都是金属修复金属，不能改变“硬到硬”的关系，在各种力量的配合下，仍会形成重新磨损的橡皮滚筒。

　　In view of the above problems of centrifugal fan, the traditional maintenance methods include surfacing, thermal spraying, electric brushing, etc., but they all have certain disadvantages: the repair welding of thermal stress caused by high temperature can not be completely eliminated, and it is easy to form material loss, resulting in bending or fracture of parts; However, brush plating is limited by the thickness of the coating, which is easy to peel off. The above two methods are metal repair metal, which can not change the "hard to hard" relationship. Under the coordination of various forces, the rubber drum will be formed again.

　　在当代西方，高分子复合材料多用于修复上述问题，应用更广泛的是美国福斯特蓝技术体系，该体系具有的附着力、优异的抗压强度等综合性能，可拆卸加工。不存在热应力，修复厚度不受限制，同时，产品具有金属数据无让步，能吸收设备的震动和震动，防止再次磨损的可能性。

　　In the contemporary western countries, polymer composite materials are mostly used to repair the above problems, the most widely used is the American foster blue technology system, which has strong adhesion, excellent compressive strength and other comprehensive properties, and can be disassembled and processed. There is no thermal stress, and the repair thickness is unlimited. At the same time, the product has metal data without concession, which can absorb the vibration and vibration of the equipment and prevent the possibility of re abrasion.