The number of teeth (or diameter) of the synchronous belt wheel is generally to determine the number of teeth of the small belt wheel first, and then determine the number of teeth of the large wheel according to the transmission ratio. In order to ensure the proper life of the timing belt, the diameter of the small timing belt wheel should be larger than the allowable minimum bending diameter in the table, and then converted into the minimum number of teeth. As long as the structure and cost allow, considering the life of the timing belt, the number of teeth of the pinion is slightly more than the allowable minimum number of teeth. After the number of teeth of the small wheel is determined, the number of teeth of the big wheel can be determined according to the transmission ratio. Then determine the center distance of the two pulleys according to the structure, and calculate the pitch line length or the total number of teeth according to the pitch of the timing belt. At this point, the transmission parameters are all determined. There are many types of timing belt pulleys. From the shape, they can be divided into flangeless B type (only the gear part BF with baffles at both ends and the gear part BS without baffles) and the flange A type , That is, in addition to the gear teeth with baffles at both ends, there is a cylindrical flange (the AF type with baffles and the AS type without baffles). For details, please refer to the timing pulley page of our company's product catalog.