Gears are important transmission parts widely used in machines and instruments.There are many types of gears and their tooth shapes are also different. The structural design principle of the tooth shape needs to ensure that the chain enters and exits the mesh smoothly and freely, minimizes the impact and contact stress of the chain links during meshing, and is easy to process.

The common geometric shapes of sprocket are three-arc straight line, two-arc straight line, two-arc convex tooth profile, one arc straight line, straight tooth profile with offset in the slot and straight tooth profile.

Design principle: The tooth profile design of the sprocket should mainly meet three requirements: meshing requirements, use requirements, manufacturability and accuracy requirements.

1. Ensure that the chain can smoothly engage in and out without interference.

2. It has sufficient capacity to accommodate chain pitch elongation.

3. It has a reasonable angle of action.

4. The tooth profile curve is adapted to the working conditions of the chain drive.

5. Conducive to biting in and preventing chain drop due to chain jump.