The utility model relates to a connector which comprises two symmetrically equipped mounting fixing parts. The mounting fixing parts are symmetrically provided with two shaft holes. A shaft passes through the two shaft holes. An annular bearing sleeve is fixed between the two mounting fixing parts. A bearing is respectively provided between the inner walls at two ends of the bearing sleeve and the shaft. The opposite surface of the mounting fixing parts are provided with annular bosses coaxially with the shaft holes for abutting against the inner rings of the bearing. The outer diameter of each annular boss is smaller than the inner diameter of each outer ring of bearing. According to the technical solution, the utility model provides the connector which causes good rotation of the outer rings of bearing.