The tooth shape model and pitch of the synchronous pulley and other meshing parameters are the same as those of the synchronous belt (for details, please refer to: arc tooth synchronous belt or trapezoidal tooth synchronous belt). All that needs to be determined is the number of pulley teeth ( or diameter) and synchronous wheel structure, etc. The number of teeth (or diameter) of the synchronous pulley is generally determined by first determining the number of teeth of the small pulley, and then determining the number of teeth of the large pulley according to the transmission ratio. In order to ensure the expected life of the synchronous belt, the diameter of the small synchronous pulley must be greater than the minimum allowable bending diameter in the table (for details, see the minimum allowable bending diameter of the synchronous belt on the new website), and then convert it into the minimum number of teeth. As long as the structure and cost allow, considering the life of the synchronous belt, it is better to have slightly more teeth than the minimum allowable number of teeth on the small wheel. After the number of teeth of the small wheel is determined, the number of teeth of the large wheel can be determined according to the transmission ratio. Then determine the center distance of the two pulleys based on the structure, and calculate the pitch line length or total number of teeth based on the pitch of the synchronous belt. At this point, all transmission parameters have been determined. There are many structures of synchronous pulleys. In terms of shape, they can be divided into flangeless type B (divided into only the gear tooth part BF with baffles at both ends and the gear part without baffles BS) and flange A type. , that is, in addition to the gear tooth part with baffles at both ends, there is also a cylindrical flange (divided into AF type with baffles and AS type without baffles). For details, please refer to the pulley page of the product center. From the perspective of the connection method with the shaft, it can be divided into three types: screws, keys and expansion sleeves (the so-called keyless connection).