Middle support bracket assembly of automotive transmission shaft

The invention discloses a middle support bracket assembly of an automotive transmission shaft. The middle support bracket assembly comprises a rubber part, a bearing pedestal, oil seals, an annular ball bearing, a spline shaft, an oil nozzle and a flange, wherein the annular ball bearing is a maintenance-free bearing with oil seals on two sides; the rubber part is vulcanized on the bearing pedestal; the annular ball bearing is mounted in the bearing pedestal; the oil seals are mounted at two ends of the bearing pedestal; the outer ring of the annular ball bearing and the bearing pedestal are in clearance fit; the inner ring of the annular ball bearing and the neck of the spline shaft are connected in interference fit; the flange and the spline part of the spline shaft are connected in interference fit; the inner end of the flange limits the inner ring of the annular ball bearing; an oil groove is formed in the upper edge of the spline part of the spline shaft in the axial direction; an oil injection hole communicating with the oil groove of the spline shaft is formed in the flange; the oil nozzle is mounted on the oil injection hole; the oil groove of the spline shaft communicates with an oil supply hole in the inner ring of the annular ball bearing. The middle support bracket assembly disclosed by the invention solves the problems that when a conventional transmission shaft assembly rotates at a high speed, heat is generated due to friction, the transmission shaft assembly shakes and generates abnormal sound, and the failure frequency of a middle transmission shaft assembly is high.