Bearing Bowl group: Dang other parts in axis Shang each other produced relative movement Shi, used to reduced power passed process in the of friction coefficient and keep axis center location fixed of parts called bearing., General are is assembled good of finished bearing, standard, replaced easy, precision than bulk himself assembled of bulk beads group has greatly of improve, cost also not high, mechanical character more stable and the durable, installation convenient, and mute effect than bulk beads of good have more, only of determine is cost relative bulk beads of to your