Research on the dynamic response of connecting rod bearing bush wear of reciprocating machine under variable working conditions

As a type of reciprocating machine, the reciprocating compressor has a compact structure and many excitation sources.Once the small end bearing of the connecting rod is worn, it is easy to cause the sintering of the bearing and the abnormal vibration of the body.Based on the characteristics of poor lubrication state and complex force of connecting rod small head bearing, a mixed lubrication model considering oil groove feed was established, and the dynamic simulation of the reciprocating compressor model with lubricated bearings was carried out;considering different speeds and gas load conditions, the law of the impact of the eigenvalues changing with working conditions was explored.The fault simulation experiment was carried out by selecting representative working conditions, which verified the correctness of the simulation method.The study found that two contact collisions between the pin and the bearing bush occurred in one cycle, the collision impact was more severe under the wear fault, and the existence of the gap made the dynamic response more sensitive to the change of working conditions.This research provides ideas for the location and feature extraction of fault symptom signal angular segments in the process of complex measured signal processing.

多种气量调节模式下往复压缩机连杆小头瓦润滑特性

针对不同气量调节模式下往复压缩机气缸内部压力变化规律不一,进而影响连杆、活塞杆等运动部件受力,易造成连杆小端轴承磨损及对机组安全稳定运行不利的问题。建立了压缩机顶开进气阀无级气量调节工作模型,采用了不同调节方式控制参数,仿真模拟不同调节方式下缸内压力变化规律;建立压缩机多体动力学模型,基于弹性流体动力润滑理论,分析了双侧平衡调节、双侧不平衡调节、单侧调节等模式下的连杆小头瓦润滑特性与动力学行为。结果表明:平衡调节碰磨角波动在8°以内,对小头瓦润滑影响不大,不平衡调节、单侧调节对小头瓦润滑影响较大,应优先降低盖侧负荷且两侧负荷偏差应不超过40%。研究成果对气量调节系统工程方案与控制策略设计具有指导作用。