尽管聚氨酯密封件的结构形式很多，但其主要形式还是U形密封圈。然而，由于聚氨酯弹性体自身的摩擦系数略高于橡胶材料，因此若液压缸和密封件的结构设计不当，尤其在长行程和薄壁缸的工况下，则会因润滑条件的恶化使液压缸产生爬行和颤震；在使用过程中密封件还会因间隙挤出造 Although the polyurethane seal structure in many forms, but its main form is U-ring. However, since the coefficient of friction of the polyurethane elastomer itself is slightly higher than that of the rubber material, if the structure of the hydraulic cylinder and the seal is improperly designed, especially in the case of long-stroke and thin-walled cylinders, the hydraulic pressure Cylinder produces crawling and tremors; in the course of the seal will be due to the gap extrusion