ABSTRACT
The pulley-and-belt analogy of a parallel-axes gear pair is convenient for the analysis of perfect parallel-axes gearing. There are many similarities in transmitting a rotation by pulley-and-belt and a corresponding gearing. Therefore, it is critical to know to what extent analogy is applicable for the analysis of gearing. A pulley-and-belt analogy can be specified in terms of diameters of the pulleys, d1 and d2, and the center distance, C. The ratio d2/d1 is equal to the angular velocity ratio, ω1/ω2, of the pulleys and is commonly designated as u. The only principal difference between a pulley-and-belt analogy of a gear pair and between the gear pair is the different direction of the force by means of which the rotation is transmitted. In the pulley-and-belt mechanism, the driving pulley pulls the driven pulley, while in the gear pair, the driving gear pushes the driven gear.
