GSB-11高速离心泵转子系统各转轴临界转速的计算

发布时间：2018-06-16 12:32

本文选题：高速离心泵 + 临界转速　；参考：《南京林业大学》2012年硕士论文

【摘要】：高速离心泵是一种基于新理论研发成功的用于输送小流量、高扬程介质的新型离心泵，与普通离心泵相比具有结构紧凑、泵零件的通用性强、工作可靠、轴向力小、寿命长、扬程曲线平坦等特点，广泛应用于石油化工、航空航天、制药、建筑消防等领域。为了保证高速泵转子系统的平稳运转，避免其工作转速靠近临界转速产生共振而影响泵的寿命，在高速离心泵设计时需要准确计算转子系统各转轴的临界转速。计算转子系统的临界转速常用的方法是有限元法和传递矩阵法。本文首先介绍了临界转速的概念、涡动理论、受重力影响下的临界转速计算原理；推导了转子动力学经典动力模型Jeffcott转子的动力特性、运动微分方程；其次，分别用材料力学公式和Ansys软件计算了简支梁的刚度，并进行比较，误差在2%以内，证明了Ansys软件在针对梁单元模型计算时的准确性，为下一步计算GSB-11高速离心泵转子系统中各转轴的临界转速提供了保证。 GSB-11高速离心泵齿轮轴承系统是受临界转速影响最大的部件之一，在计算其临界转速前，必须先对模型进行简化，本文使用Ansys软件对GSB-11高速泵转子系统分别建立齿轮、轴承、各转轴的力学模型，对中间轴进行模态分析，计算其一阶、二阶、三阶固有频率，然后根据理论公式计算固有频率，并使用随机振动法测量中间轴转子系统的固有频率，以比较误差的大小。最后，使用Ansys软件对无阻尼偏置圆盘转子、中间轴转子系统及高速轴转子系统进行了转子动力学计算，画出高速轴的坎贝尔图，，解得高速轴的临界转速。由于系统的复杂性、模型不同的简化过程、边界条件的选取等等，采用Ansys软件计算和实验测试的临界转速都可能会有一定误差，但通过综合Ansys软件计算和实验获得的结果，可以预判转子系统发生共振的转速范围，避免工作速度出现在临界转速附近，将有效降低设计成本，具有一定的工程实际应用价值。
[Abstract]:High speed centrifugal pump is a new type of centrifugal pump which is successfully developed based on the new theory for conveying small flow rate and high lift medium. Compared with ordinary centrifugal pump, it has compact structure, strong generality of pump parts, reliable work, small axial force and long life. Flat lift curve, widely used in petrochemical, aerospace, pharmaceutical, building fire and other fields. In order to ensure the smooth operation of the high speed pump rotor system and avoid the resonance between the working speed and the critical speed, it is necessary to accurately calculate the critical speed of the rotor shaft in the design of the high speed centrifugal pump. Finite element method and transfer matrix method are commonly used to calculate the critical speed of rotor system. In this paper, the concept of critical speed, the theory of vortex, the calculation principle of critical speed under the influence of gravity, the dynamic characteristics and differential equations of Jeffcott rotor, a classical dynamic model of rotor dynamics, are first introduced in this paper. The stiffness of simply supported beam is calculated by material mechanics formula and Ansys software, and the error is less than 2%. The accuracy of Ansys software in calculating beam element model is proved. It provides a guarantee for calculating the critical rotational speed of each shaft in the rotor system of GSB-11 high speed centrifugal pump. The gear bearing system of GSB-11 high-speed centrifugal pump is one of the parts most affected by the critical speed. The model must be simplified first. In this paper, the mechanical models of gear, bearing and rotating shaft are established by using Ansys software to calculate the first, second and third natural frequencies of the intermediate shaft. Then the natural frequency is calculated according to the theoretical formula and the natural frequency of the intermediate shaft rotor system is measured by random vibration method to compare the magnitude of the error. Finally, the rotor dynamics of the undamped offset disk rotor, the intermediate shaft rotor system and the high-speed shaft rotor system are calculated by using Ansys software. The Campbell diagram of the high-speed shaft is drawn and the critical speed of the high-speed shaft is obtained. Because of the complexity of the system, the simplification process of different models, the selection of boundary conditions and so on, there may be some errors in the calculation of critical rotational speed by using Ansys software and the experimental test, but the results obtained by synthesizing the calculation of Ansys software and the experimental results, The range of rotor system resonance speed can be forecasted and the working speed can be avoided near the critical speed which will effectively reduce the design cost and have certain practical application value.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH311

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