宽度不大的防尘密封装置有效性基本上取决于其中是否存在油脂。只要有足够的油脂,杂质就无法进入轴承。一般的“O”形密封圈很难保持油脂,因而不容易达到理想的密封要求。为了改善密封,可嵌入一些毡环或毡条,或者加嵌泡沫塑料。但这些材料常带来严重的摩擦,且难以嵌在宽度不大的密封内。当摩擦和圆周速度超过一定值时,这些材料会撕裂而脱出。 The effectiveness of a small dust seal largely depends on the presence or absence of grease. As long as there is enough grease, impurities can not enter the bearings. General “O” ring seals are difficult to maintain grease, so it is not easy to achieve the desired sealing requirements. In order to improve the seal, it is possible to embed some felt rings or felt strips, or embed foam. However, these materials often cause serious friction, and difficult to embed in the width of the seal is not large. When the friction and peripheral speed exceeds a certain value, these materials will tear and come off.