The wire roller is commonly used component when wire passing is required, it can be used in coil winding machine and the textile machinery as well.The porcelain ring is mounted on the bearing, it will rotate by the thread and wire passing on the surface of the ring.Thus the sliding friction has been converted to the static friction.Bt at the start and stop, in order to overcome the inertia, there will be a partial sliding friction. The surface ploish degree of the porcelain ring reaches Ra0.2; the bearing during rotation is under 0.15, We select the 99%AL2O3 as the material with the hardness of HRA88 and the density of 3.85....