以非道路高压共轨柴油机连杆小头轴承为研究对象,搭建了电涡流法轴心轨迹测试系统,开发了数据采集软件,在怠速工况下对连杆小头轴承轴心轨迹进行了测试与分析。研究结果表明:基于电涡流法的轴心轨迹测试实现了电涡流信号与曲轴转角信号的同步采集;怠速工况下轴承油膜厚度在0~20 μm范围内周期性波动,峰值出现在进、排气阶段,最小油膜厚度位置出现在气缸最大燃烧压力点后21°,最小油膜厚度为0.88 μm;轴心轨迹运动以上下窜动为主,轴承主承载区分布在轴承周向60°~90°与270°~300°区间。
Taking the connecting rod small end bearing of non-road high pressure common rail diesel engine as the research object, the eddy current method-based axial trajectory testing system was built, and the data acquisition software was developed. The axial trajectory testing and analysis of connecting rod small end bearing were carried out under idle condition. The results show that the axial trajectory testing based on eddy current method realizes the synchronous acquisition of eddy current and crankshaft angle signal. Under the idle condition, the oil film thickness of bearing fluctuates periodically in the range of 0-20 μm, the peak value appears in the intake and exhaust stages, and the minimum oil film thickness is 0.88 μm and appears at 21° after the in-cylinder maximum combustion pressure point. The motion of bearing axial trajectory is primarily characterized by vertical oscillation, and the main load-bearing zones of bearing distribute in the circumferential intervals of 60°-90° and 270°-300°.