液压缸运动的非线性动态特征  

NONLINEAR DYNAMIC CHARACTERISTICS OF MOVING HYDRAULIC CYLINDER

作　　者：王林鸿[1] 吴波[1] 杜润生[1] 杨叔子[1] 

机构地区：[1]华中科技大学机械科学与工程学院

出　　处：《机械工程学报》2007年第12期12-19,共8页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2005CB724101)

摘　　要：根据非线性动力学的观点,通过理论分析和试验验证,研究非线性弹簧力和非线性摩擦力对液压缸动态特性的作用。得出三种不同节流调速回路工况下液体弹簧刚度随位移变化规律,发现不同工况各自呈现出软弹簧特性或硬弹簧特性。提出非线性弹簧力作用可以用有阻尼的Duffing方程描述,非线性摩擦力作用可以用Van Der Pol方程描述,非线性弹簧力和非线性摩擦力耦合作用可以用Lienard方程描述。指出液压缸低速爬行原因是在特定工况下软弹簧特性引起的'跳跃现象'和非线性摩擦力引起的自激振动共同作用的结果。方程的解在不同工作条件下具有不同的形态,说明液压缸非线性动态特性复杂多变。In terms of nonlinear dynamics, the actions of nonlinear spring force and nonlinear frictional force on dynamic characteristics of moving hydraulic cylinder are emphatically studied by means of theoretical analysis and experimental verification. Varying regularities of spring stiffness with piston displacement controlled by three types of hydraulic throttle-governing circuits are obtained. Soft spring property or hard spring property shown separately by above different working situations are found. The conclusions that the effect of nonlinear spring can be described by Dutiing equation, the effect of nonlinear frictional force can be described by Van Der Pol equation, and their coupling effect can be described by Lienard equation are achieved. The reasons why hydraulic cylinder creeps in lower velocity are common acting results of the jump phenomenon caused by soft spring property and the self-excited vibration caused by nonlinear frictional force in specific working situation are expressed. Solutions of the equations are of different patterns in terms of different working conditions. All above illustrate that the nonlinear characteristics of moving hydraulic cylinder are complicated and changeable.

关 键 词：液压缸 非线性动态特征 Duffmg方程 VAN Der POL方程 LIENARD方程 跳跃现象 自激振动 

分 类 号：TH113[机械工程—机械设计及理论]