【摘要】 利用Gallina二自由度模型对螺旋升降机在下降过程中发出的异响声和振动进行研究。指出由于螺旋升降机的惯性矩阵是非对称矩阵,所以垂向平动和绕铅垂轴转动存在非对称的耦合现象。同时,研究表明惯性矩阵的非对称性是造成系统自激振动的主要原因,并得出了螺旋升降机动力学稳定性的判定依据。结合某螺旋升降机的参数,利用Math CAD分别得到了摩擦系数、丝杠中径和轴向载荷对系统稳定性影响的曲线,并提出了避免螺旋升降机自激振动的措施。更多还原

【Abstract】 Research the squeak noise and vibration when screwjack mechanism goes down using Gallina two degrees of freedom model. Point out that vertical translation and rotation around the vertical axis exist asymmetric coupling phenomenon because the inertia matrix of screwjack mechanism is asymmetric matrix. Simultaneously,research showthat the asymmetry of inertia matrix is the main reason causing self-excited vibration. And get the stability criteria of trapezoidal screw-nut auxiliary. Combining the parameters of screwjack mechanism and using Math CAD,get the curves of friction coefficient,screwdiameter and axial load impacting on system stability. The measures of avoiding self-excited vibration are also put forward.更多还原