推导了松配合矩形花键联轴器考虑脱开临界状况的啮合力模型,基于有限元法建立了考虑圆柱瓦滑动轴承非线性油膜力和花键联轴器啮合力作用的转子-联轴器-轴承系统动力学模型,并用数值积分研究了联轴器啮合力对转子-轴承系统稳定性的影响规律。研究结果表明:花键联轴器的横向刚度对其连接的转子-轴承系统发生油膜振荡的失稳转速影响较小,而转角刚度影响较大;对于松配合花键联轴器,如果不考虑其转角刚度,用线性化的啮合刚度模化联轴器得到的转子-轴承系统的失稳转速要高于用力模化的系统的失稳转速;因此,工程用线性刚度代替啮合力模化联轴器将掩盖系统真实的失稳转速,这种简化对转子系统运行来说是不安全的。研究结果为获得转子-花键联轴器-轴承系统真实的失稳转速提供理论依据,研究思路对其他类型联轴器动力学建模具有借鉴意义。
Meshing force model of loosely meshed spline coupling considered the critical disjointed condition is derived, dynamic equation of rotor-spline coupling-bearing system with the action of coupling mesh and nonlinear oil forces is established based on finite element analysis. The influence of spline coupling on stability of rotor-bearing system is simulated by the numerical integral method. Research results show that the influence of lateral stiffness of spline coupling on system threshold speed of oil whipping instability is weak, however, the influence of angular stiffness is larger. For loosely meshed spline coupling, the angular stiffness is not considered, system threshold speed of instability obtained by linearized mesh stiffness of coupling is larger than the one obtainted by mesh force. Therefore, in real engineering project, meshing stiffness, instead of meshing force, used to model coupling will conceal the real threshold speed of instability of rotor-bearing system, and this simplification is unsafe for operation of rotor system. Research results can provide theoretical evidence for obtaining the real threshold speed of instability of rotor-spline coupling-bearing system, and this approach can provides guidance for other kinds of couplings.