The half shaft is shorter in length than a propeller shaft, so it is designed to be stiff without being too bulky. However, when the length of the half shaft increases, it is often necessary to increase its roughness in order to ensure stiffness. According to the principles of material mechanics, the closer the material is to the center of the circle, the less role it plays in transmitting the torsional force. Therefore, under the premise of accurately calculating the torque, we can design the half shaft as hollow, which not only reduces its own rotational inertia, but also effectively saves material.
