1. Acceleration and deceleration, which is often called a variable speed gearbox;
2. Change the transmission direction, for example, we use two sector gears to transmit the force vertically to another rotating shaft;
3. Change the torque. Under the same power conditions, the faster the gear, the smaller the torque on the shaft, and vice versa;
4. Clutch function: We can achieve the purpose of separating the engine from the load by separating the two originally meshing gears. Such as brake clutch, etc.;
5. Distribute power. For example, we can use one engine to drive multiple slave shafts through the gearbox spindle, so as to realize the function of one engine driving multiple loads.