倒拉式变频液压电梯系统的轿厢振动分析

Cabin vibration of VVVF hydraulic elevator system with pull-cylinder

针对倒拉式变频液压电梯的轿厢振动加速度超标现象,分析系统的动态特性以及系统中主要激振源对轿厢振动的影响.通过对电梯轿厢的原始振动加速度信号和液压系统的负载压力信号进行频谱分析,初步诊断轿厢测速装置中的啮合振动是引起轿厢振动加速度超标的主要原因.建立了系统垂直方向上8自由度的集中质量动力学模型.理论分析结果表明,集中质量模型仅适合于分析低频振动的影响.对整个系统进行试验模态分析,所得低阶固有频率值能与理论计算结果较好地吻合.分析结果还表明,存在与测速装置中啮合频率相吻合的频带,说明该装置确实是引发轿厢加速度超标的振源.采用相应的隔离方法来消除其影响,并通过试验证实了方法的有效性.

The cabin-vibration characteristics of the variable voltage variable frequency （VVVF） hydraulic elevator with pull-cylinder were discussed. The acceleration of the cabin and the load pressure of cylinder were analyzed. And the mesh between the gear and rubber rack of the speed-measuring device was tentatively diagnosed as the main excitation. An 8-degree-of-freedom dynamic model of vertical direction for the system was established and modal analysis on the whole system was performed. The experiments of modal analysis for the system were carried out. The results showed that the natural frequencies of the system approached the mesh frequency of the speed-measuring device, which indicated that the speed-measuring device was the vibration source of the cabin vibration. A way of vibration isolation for the speed-measuring device was presented. And the experiments showed the validity.