When calculating the diameter of the large sprocket, the calculation should be based on the following two points at the same time:
1. Calculate based on the transmission ratio: usually the transmission ratio is limited to less than 6, and the transmission ratio is optimal between 2 and 3.5.
2. Select the transmission ratio according to the number of teeth of the pinion: when the number of pinion teeth is about 17 teeth, the transmission ratio should be less than 6; when the number of pinion teeth is 21~17 teeth, the transmission ratio is 5~6; when the number of pinion teeth is 23~ When the pinion has 25 teeth, the transmission ratio is 3~4; when the pinion teeth are 27~31 teeth, the transmission ratio is 1~2. If the outer dimensions allow, try to use a small sprocket with a larger number of teeth, which is good for the stability of the transmission and increasing the life of the chain.
The basic parameters of the sprocket: the pitch p of the matching chain, the maximum outer diameter of the roller d1, the row pitch pt and the number of teeth Z. The main dimensions and calculation formulas of the sprocket are shown in the table below. The diameter of the sprocket hub hole should be smaller than its maximum allowable diameter. The national standards for sprockets have not specified specific sprocket tooth shapes, only the maximum and minimum tooth space shapes and their limit parameters. One of the more commonly used tooth shapes at present is the three-round arc.
Post time: Dec-27-2023