理论力学中考虑定滑轮轴承摩擦因素的动力学问题的分析和求解
Analysis and Solution of Dynamic Problems Considering Friction of Fixed Pulley Bearings in Theoretical Mechanics

由定滑轮和绳系重物所组成的这类系统的动力学问题的例题和习题常见于诸多的理论力学教科书中，然而在这些例题和习题的设置当中，均没有考虑轴承摩擦因素的影响，由此所得到计算结果也就不能真实、客观地反映系统的运动规律。本文以一具体的定滑轮–绳系重物系统的动力学问题为例，通过推导演示说明了如何将轴承的摩擦因素计入到系统动力学问题的分析和求解当中，从而使得求解结果能够更加客观地反映系统的运动规律。本文所给出的这种分析和求解思路也可以类比地移栽到其他需要计入轴承摩擦影响的定滑轮–绳系重物系统动力学的分析和求解上。
Examples and exercises of dynamics problems of fixed pulley-rope weight systems are common in many theoretical mechanics textbooks. However, in the setting of these examples and exercises, the friction factors of bearing are not considered, so the calculation results can not reflect the movement law of the system truly and objectively. The dynamics problem of a specific fixed pulley-rope weight system being taken as an example, it is shown how to incorporate the friction factors into the analysis and solution, so that the solution results can more objectively reflect the motion law of the system. The analysis and solution ideas given in this paper can also be applied to the analysis and solution of other fixed pulley-rope weight system dynamics in which the influence of bearing friction factors needs to be included.