The plastic bearing unit is unique in light weight, corrosion resistance, easy installation and maintenance-free. At the same time, it has the shock absorption and shock resistance performance of common cast iron bearing seats or stamped bearing seats. With the continuous development of new bearing housing materials, more and more widely used in engineering. According to different situations, plastic outer spherical bearings can be made of different materials such as POM, HDPE, PP, UPE, PTFE, etc. Relative to plastic outer spherical bearings, PBT is generally used.