一般起升机构吊重轨迹偏差分析

Deflection Analysis of Load Trajectories for General Hoisting Mechanisms

提出了一种分析一般起升机构吊重轨迹偏差的系统化方法.通过系统平衡方程与协调条件建立了系统位移、钢丝绳拉力等参数所满足的一阶微分方程.详细讨论了方程中涉及的各种变量的性质和计算方法,得到了空间滑轮公切点位移和速度、钢丝绳拉力方向及其变化率,给出了卷筒参数协调条件、系统绳长协调条件,并提出了一种求解空间滑轮角速度的方法.滑轮的转动方向决定了其两端拉力关系,然而微分方程求解过程中可逐步求得各滑轮角速度,所以针对双联卷筒单分支缠绕的系统,该方法解决了系统中有滑轮转动方向难以确定的问题.这些问题的解决方法具有一定的普适性,对于一般起升机构的设计和分析有一定的参考价值.

A systematic method for analyzing load trajectory deflections of general hoisting mechanisms was presented. In this method, the fwst order differential equations for generalized degrees of freedom and wire rope tensions were established based on the governing equations of equilibrium and compatibility conditions. Properties and formulations of the variables involved in these equations were studied in detail, in which the displacements and velocities of tangent points between pulleys and the tension directions of ropes as well as the change rates of tension directions were derived. The compatibility condition for drum parameters, as well as for rope lengths in the system was provided. A method to solve the angular speeds of spatial pulleys was proposed. In the process of solving the differential equations, the pulley＇ s angular speed which determined the relation of tensions at both ends of the pulley, was derived at each step. The systematic method is applicable to hoisting mechanisms with single reeving branches, and solves the difficult problem of determining the rotating directions of pulleys. To a large extent the proposed method is universal and makes a reference for designing and analyzing general hoisting mechanisms.