Dual rolling bearing type sucker rod centralising device

The utility model relates to a double-roller bearing type of pumping rod centralizer with characters of corrosion-resistance, wear-resistance and high fatigue life to solve the problem of eccentric wear of pumping rod and tube in oil well, which comprises a centralizer rod provided with threads at the two ends, a sectional type casing, a rolling sphere, a spacing ring and a restraint ring. The utility model is characterized in that two provided casings are composed of two casing sections respectively, on which 4 (5 or 6) rolling spheres made of high hardness nanophase ceramics material with characters of corrosion-resistance and wear-resistance mounted in the holes on the jut of connections of two casing sections. The rolling spheres can be arrayed in regular quadrangle (or pentagon or hexagon). The two casings and rolling spheres are crossed arrayed along the axis of centralizer rod and fastened by spacing ring and restraint ring. Threads are provided at the both ends of centralizer rod to connect pumping rods at two sides.