前置式气平衡抽油机失载时运动与动力分析

KINEMATIC AND DYNAMIC ANALYSIS OF UNLOADED AIR BALANCED PUMPING UNIT

根据机械动力学的基本原理,用求解机器真实运动的方法分析了电机工作状态、平衡气压、抽油机冲次、失载位置、系统的转动惯量等因素对气平衡抽油机失载后各构件的受力和运动状态的影响。动力分析表明,高速级的转动惯量和平衡气压是影响失载后构件受力的主要因素,各构件和运动副的受力经过一个突变后再逐渐增加,接近上死点时达到最大值,对失载后抽油机的保护,除适当加强连杆系统,抵抗短时过载的冲击外,还有必要安装使平衡系统具有减压、放气和阻尼、缓冲功能的保护装置。

According to the principle of dynamics of machinery,the effect of motor rotation,balancing air pressure,number of strokes,unloaded time and moment of inertia on the load and state of mo tin of pumping unit members is studied.The dynamic analyses show that the moment of inertia at a high speed and the balancing air pressure are main factors affecting the loading on the members.Forces on every member and kinematic pair had a sudden change and then increased continueously.The forces reached the maximum values when the members approached the upper dead point.For the protection of a unloaded pumping unit,the connecting rod system should be strengthened to resist the impact of instantaneous overload and the protective units with the functions of reducing pressure,discharge and damping to buffer the impact load should be installed.