Mechanical Advantage: Pulley System Principles скачать в хорошем качестве

Mechanical Advantage: Pulley System Principles

A note about the size of the pulley sheave & it's effect on efficiency: A larger ratio between the sheave diameter vs. the rope diameter will increase rope strength, but does not necessarily, nor directly affect the pulley efficiency. What affects the pulley efficiency are two things: 1. The coefficient of friction between the bearings/bushing and the axle 2. The difference in diameters between the outer pulley wheel vs. the pulley axle. All things being equal, the smaller the axle, the bigger the diameter difference & thus a more efficient pulley due to better leverage ratios. You can also do this by increasing the size of the sheave of the pulley, so long as your axle remains the same. The net effect of this diameter difference changes the lever length ratio, thus affecting the mechanical advantage.