# Pulley

> [HTML Version](pulley.html)

The load can be defined defining a torque on the pulley and its pretension coming from a belt. 

(./images/all_img45.png) (./images/all_img46_zoom90.png)

The direction of torque can either be defined by its sign or by the selection “Shaft is driven”/Shaft is driving”. The positioning of the contact surface is given by an angle of first contact, which starts clockwise from zero on the y-axis, and followed by the wrap angle as shown in the picture below. The pulley diameter can be set straight away or by means of its teeth number and pitch.

A torque will lead to an increase force on one side of the belt and to a decreased force on the other side. This is the correct model in case no tensioning pulley is used.