logo logo

Material Position Of Crusher Grit Liner

2019-10-10the invention of the rolling bearing, in the form of wooden rollers supporting, or bearing, an object being moved is of great antiquity, and may predate the invention of the wheelthough it is often claimed that the egyptians used roller bearings in the form of tree trunks under sleds, this is modern speculationhey are depicted in their own drawings in the tomb of djehutihotep as moving.