联轴器对内燃机轴系扭振影响及减振研究

发布时间：2018-07-26 09:38

【摘要】：在"一带一路,铁路先行"的理念提出以后,内燃机车的发展迎来了新的机遇与挑战。内燃机轴系中联轴器是连接轴系并传递扭矩的关键部件,在内燃机车实际运行过程中,轴系启动工况发生扭转共振以及联轴器失效的现象频频出现,因此轴系中联轴器的使用关系到轴系的安全性与可靠性,具有重大的研究意义。以典型内燃机车动力总成轴系联轴器为研究对象,对比了大刚度联轴器与高弹性联轴器的参数特性,采用轴系扭振仿真计算与扭振测试相结合的方法,研究了联轴器对内燃机轴系扭振特性的影响。结合仿真计算与试验结果,分析得到了定刚度橡胶联轴器、弹簧阻尼联轴器和大刚度联轴器对应的内燃机轴系的扭振特性,研究了三种联轴器与轴系的优化匹配策略。三种联轴器轴系的联轴器扭振模态均避开了内燃机的3.0主谐次激励,但是内燃机的6.0谐次或1.0与0.5等低谐次激励会与轴系产生共振。针对弹簧阻尼联轴器主、被动端碰撞力矩难以测试的共性问题,提出了一种基于动态扭角差和角加速度的联轴器受力测试方法,对轴系联轴器动态扭角差和受力进行了测试分析,获得了轴系联轴器的扭振交变力矩、过渡工况惯性力矩和碰撞力矩。试验发现,弹簧阻尼联轴器启动工况最大交变扭角差峰-峰值达到31°,联轴器主、被动端最大扭转角度为15.7°,证实了在启动工况下弹簧阻尼联轴器主、被动端可能会有短暂的碰撞现象,对应最大惯性力矩达到了 9914Nm。针对弹簧阻尼联轴器在实际应用中出现的失效情况,校核了联轴器花键套螺栓预紧力,建立了弹簧阻尼联轴器的有限元模型,采用联轴器的扭角差测试结果对联轴器受力分析得到联轴器在启动工况受到的最大惯性力矩,分析联轴器失效处的应力情况,应用S-N法估算了联轴器的使用寿命,失效处应力值虽然小于联轴器的屈服极限但是大于其疲劳强度极限,因此可能造成联轴器的疲劳破坏。提出了一种轴系采用连续变刚度联轴器的优化匹配策略,并在某型内燃机轴系中得到了成功应用。轴系匹配连续变刚度联轴器,不仅能使轴系主要模态频率避开内燃机3.0与6.0等主简谐激励频率,还可避免1.0和0.5谐次等低谐次扭振共振,使轴系各部件的扭振幅值得到有效控制,故障工况下轴系扭振幅值也满足限值,启动工况下联轴器两端的扭角差也得到了明显优化。综上所述,本文提出的基于动态扭角差和角加速度的联轴器受力测试方法,可用于联轴器常规受力及碰撞力矩的测试,对不同联轴器各工况进行了受力分析;提出了一种轴系采用连续变刚度联轴器的优化匹配策略,取得很好的轴系扭振优化结果。
[Abstract]:After the concept of "Belt and Road, Railway first" was put forward, the development of diesel locomotives ushered in new opportunities and challenges. The coupling is the key component of connecting shafting and transmitting torque in internal combustion engine shafting. In the actual operation of diesel locomotive, torsional resonance occurs in the starting condition of shafting and failure of coupling occurs frequently. Therefore, the use of coupling in shafting is of great significance to the safety and reliability of shafting. Taking the shaft coupling of typical diesel locomotive powertrain as the research object, the parameter characteristics of the large stiffness coupling and the high elastic coupling are compared, and the method of simulating the torsional vibration of the shaft system and testing the torsional vibration is adopted. The effect of coupling on torsional vibration characteristics of internal combustion engine shafting is studied. Combined with the simulation and experimental results, the torsional vibration characteristics of the internal combustion engine shaft system corresponding to the fixed stiffness rubber coupling, the spring damping coupling and the large stiffness coupling are analyzed, and the optimization matching strategies of the three types of coupling and shafting are studied. The torsional vibration modes of the three types of coupling shafting all avoid the 3.0 main harmonic excitation of the internal combustion engine, but the 6.0 harmonic or the low 1.0 and 0.5 harmonic excitations of the internal combustion engine will resonate with the shafting. Aiming at the common problem that the impact moment of spring damping coupling is difficult to be measured at the active and passive end, a method of force measurement based on dynamic torsional angle difference and angular acceleration is proposed. The dynamic torsional angle difference and force of shafting coupling are tested and analyzed. The torsional vibration alternating moment, transient inertia moment and impact moment of shafting coupling are obtained. The test results show that the maximum alternating torsional angle difference between peak and peak reaches 31 掳, and the maximum torsional angle is 15.7 掳at the active and passive ends of the coupling. It is proved that the spring damping coupling is the main part of the spring damping coupling under the starting condition. There may be a transient collision at the passive end, corresponding to a maximum inertia torque of 9914 Nm. In view of the failure of spring damping coupling in practical application, the pretightening force of spline sleeve bolt of coupling is checked, and the finite element model of spring damping coupling is established. The maximum inertia moment of coupling under start-up condition is obtained by using the test results of torsional angle difference of coupling. The stress at failure point of coupling is analyzed, and the service life of coupling is estimated by S-N method. The failure stress value is smaller than the yield limit of the coupling, but larger than its fatigue strength limit, so it may cause fatigue failure of the coupling. An optimal matching strategy for shafting with continuous variable stiffness coupling is proposed and successfully applied in a certain internal combustion engine shafting. The shafting matching continuous variable stiffness coupling can not only avoid the main harmonic excitation frequencies such as 3.0 and 6.0 of the internal combustion engine, but also avoid the low harmonic torsional resonance of 1.0 and 0.5 harmonics. The torsional amplitude of the shafting components is controlled effectively, the torsional amplitude of the shafting meets the limit value under the fault condition, and the torsional angle difference between the two ends of the coupling is obviously optimized under the starting condition. To sum up, the test method of coupling force based on dynamic torsional angle difference and angular acceleration is put forward in this paper, which can be used to test the conventional force and impact moment of coupling. An optimal matching strategy for shafting with continuous variable stiffness coupling is proposed, and good results of torsional vibration optimization are obtained.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U262

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