泵水润滑轴承-转子系统的动力学特性研究

Rotor Dynamic Characteristics of Water Lubricated Bearing for Pumps

针对当前泵水润滑轴承-转子系统模态分析与稳定性等动力学特性研究相对薄弱等问题,以设计的某高压多级泵为例,通过合理简化,建立研究该泵轴承-转子系统动力学特性的三维实体模型与数学模型;利用ANSYS进行的考虑惯性效应、不同角速度的多载荷模态分析生成了刚性支承坎贝尔图,计算得到了考虑陀螺效应的前4阶固有频率、3 000 r/min载荷下的正进动涡动转速(即临界转速);分析得出了系统在工作转速与非工作转速下的轴系不平衡响应曲线;恒定转速下突加激励时转子系统的瞬态特性分析表明,虽然突加激励力后转子系统会出现较大振动,但随后振幅逐渐减小并趋于稳定,说明该水润滑轴承-转子系统是稳定的刚性系统。

Taking HP multistage pump as example, physical model and mathematical model of its bearing-rotor system were established though appropriate simplified process. Four stiffness coefficients and four damp coefficients which express its dynamic characteristic of the water membrane bearing were deduced and calculated. Rigid support Campbell drawing by multi-load modal analysis on ANSYS considering inertial effect was generated. The fore four natural frequency considering inertial effect and critical speed on the load of 3 000 r/min were also obtained. Unbalance response curves of the shafting on working speed and unworking speed were obtained by analysis. This water lubricated bearing-rotor system was certified to be a steady rigid system by transient state characteristic analysis which driving force was feed in a sudden and the rotational speed was considered. Though rather large vibration may appear in the beginning of this period, oscillating amplitude will be reduced gradually and return to stabilization soon.