Monitoring of Abnormal Vibration to Prevent Seizure of Crosshead Bearings
Monitoring of Abnormal Vibration to Prevent Seizure of Crosshead Bearings
复制标题
监测异常振动以防止十字头轴承卡住
DOI：
10.5988/jime.39.335
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
D. Nakahara
中科院分区：
文献类型：
--
作者：
T. Kitahara;H. Yamamoto;M. Otsubo;D. Nakahara
大型二冲程柴油机十字头轴承工作在恶劣的润滑条件下，因为在高比负荷下，流体动力作用受到低幅、低速振荡的限制。最近的趋势是发动机更紧凑，输出更多，提高了轴承的比负荷，从而显著增加了润滑严重程度。因此，找到一种防止十字头轴承卡住的方法是非常重要的。在这项研究中，我们评估了一种使用动态加载轴承卡住试验台来监测异常振动的技术，该试验台能够模拟实际发动机中十字头轴承的负载模式和相对振荡。振动尖峰出现在曲柄转角为±90度左右，每个周期的摆动速度为零。随着润滑严重程度的增加，在曲柄转角约为90度时，往往会产生严重的金属-金属接触引起的异常振动尖峰，此时油膜厚度达到最小。如果在检测到异常振动后立即正确地进行磨合，则轴承表面是一致的，从而消除了严重的金属对金属接触。这种异常振动监测技术是防止十字头轴承卡住的有效手段。
The crosshead bearing in large two-stroke diesel engines operates under severe lubrication conditions because hydrodynamic action is limited by low-amplitude, low-velocity oscillation under high specific load. The recent trend toward more compact engines with increased output raises the bearing specific load, thereby significantly increasing the lubrication severity. Therefore it is very important to find a means of preventing seizure of the crosshead bearing. In this study we evaluated a technique for monitoring abnormal vibration using a dynamically loaded bearing seizure test rig capable of simulating load patterns and relative oscillations of the crosshead bearing in actual engines. Vibration spikes occur around the crank angles of ±90 degrees where the oscillating speed is zero during each cycle. When the lubrication severity increases, an abnormal vibration spike caused by severe metal-to-metal contact is frequently generated at a crank angle of approximately 90 degrees, where the oil film thickness reaches a minimum. If running-in is properly carried out immediately after detection of the abnormal vibration, the bearing surface is conformed, thereby eliminating the severe metal-to-metal contact. This monitoring technique for abnormal vibration can be an effective means of preventing seizure of the crosshead bearing.