The early damage of plain ina bearing is much more common than that of bearing burnout, so it is very important to prevent the early damage of plain bearing. The correct maintenance of sliding bearing is an effective way to reduce the early damage of bearing, and also a reliable guarantee to extend the life of bearing. Therefore, in the daily maintenance and repair of the engine, it is necessary to pay attention to the appearance and shape of the alloy surface, back, end and edge corner of the bearing. If there is any sign of abnormal or half worn, it is necessary to find out the cause carefully, and take corresponding measures to improve the working conditions of the bearing, and pay attention to the prevention of the early damage of the sliding bearing.

1. Measurement of coaxiality and roundness of main bearing hole of diesel engine body. For the measurement of the coaxiality of the main bearing hole of the engine block, the coaxiality dimension of the diesel engine block must be measured accurately, and the runout of the crankshaft shall be measured at the same time, so as to select the thickness of the bearing bush, so as to make the oil lubrication clearance reach the same in each shaft position. In case that the diesel engine has run over the tiles, runaway, etc., the coaxiality of the main ina inlet bearing hole of the engine body must be tested before assembly. The total length of the nodular iron crankshaft is not more than 0.14mm, and the total length of the steel crankshaft is not more than 0.12mm. At the same time, the roundness and cylindricity of the bearing hole of the engine body are also required.

2. Improve the maintenance and assembly quality of INA Bearing and strictly control the qualification rate of connecting rod. Improve the reaming quality of the bearing, ensure that the back of the bearing is smooth and spotless, and the locating convex points are intact; the elastic opening of the bearing is 0.5-1.5mm, which can ensure that the bearing bush is closely connected with the bearing seat hole with the help of its own elastic force after assembly; measure the parallelism and twist of the new and old connecting rods, and prohibit the unqualified connecting rods from getting on the train; each of the upper and lower bearing shells installed in the bearing seat The end shall be 30-50mm higher than the bearing pedestal plane, and the higher amount can ensure that the bearing and the bearing pedestal are closely matched after tightening the bearing cover bolts according to the specified torque, generating enough friction self-locking force, the ina inlet bearing will not be loose, and the heat dissipation effect is good, The working surface of ina bearing can't reach 75% - 85% contact mark by scraping matching method, so the fit clearance between bearing and journal can meet the requirements without scraping. In addition, pay attention to check the processing quality of crankshaft journal and bearing during assembly, strictly implement the repair process specification, prevent improper installation due to improper installation method and uneven or non-conforming torque of bearing bolt, resulting in bending deformation and stress concentration, leading to early damage of INA Bearing.