定滑轮两侧绳内张力差及摩擦力分析

Analysis of the Tension Difference between the Ropes on Both Sides of the Fixed Pulley and the Friction Force

选择定滑轮和绳组成的质点系为研究对象,根据质点系角动量定理,计算了定滑轮两侧绳所受的张力差,并且分析了仅当定滑轮质量不能忽略时的情况。结果表明,滑轮两侧所受拉力与绳和滑轮的质量、轮的半径、轴摩擦力矩以及滑轮的角加速度有关,在极限情况下,滑轮两侧绳内张力趋于相等。定滑轮轮缘与绳子之间的静摩擦在促使滑轮加速转动。

The particle system composed of fixed pulley and rope is chosen as the object of study. According to the angular momentum theorem of the particle system, the tension difference between the ropes on both sides of the fixed pulley is calculated, and the condition that the quality of the fixed pulley can not be neglected is analyzed. The results show that the tension between the two sides of the pulley is related to the quality of the rope and pulley, the radius of the wheel, the friction moment of the shaft, and the angular acceleration of the pulley. In the extreme case, the tension between the two sides of the pulley tends to be equal. The static friction between the flange of the fixed pulley and the rope causes the pulley to rotate rapidly.