Flywheel effect refers to that in order to make the stationary flywheel rotate, you must make a lot of force at the beginning, push it repeatedly in circles, and every turn is very laborious, but every round of effort will not be wasted, and the flywheel will rotate faster and faster. When a high speed is reached, the momentum and kinetic energy of the flywheel will be great, and the external force needed to stop it in a short time will be great, so that it can overcome the great resistance to maintain the original movement. In mechanical structure, it is generally used to pass through the dead point in the moving mechanism.