With each press of the hydraulic jack, its internal valves will alternately open and close, ensuring the transmission and blockage of hydraulic oil. Even after removing the drive, it can still maintain the lifting state, which is the self-locking of the hydraulic jack. Therefore, some netizens have raised the question of how the screw jack completes self-locking?

The principle of self-locking of a screw jack is based on the mechanical properties of the screw structure. A screw jack is a simple mechanical device consisting of a screw and a nut. A screw is a rod-shaped object with threads, which are a spiral shape that rotates along the body of the rod. A nut is a sleeve with threads that can move along the threads of a screw.

The self-locking principle of a screw jack is generally related to friction and the angle of thread inclination, and there is a certain amount of friction between the screw and nut. When the nut moves along the thread of the screw, the friction between the threads will prevent the nut from freely sliding down. The thread of a screw is usually designed with a specific bevel angle. This angle requires the nut to overcome the frictional force of the thread when moving outward at the top, but when moving inward at the top, the frictional force will automatically help the nut lock in place.

When you use a screw jack to lift a heavy object, rotate the screw upwards and the nut will move upwards along the thread, overcoming friction. Once the screw stops rotating, the nut will be prevented by friction and automatically lock in its current position, preventing the heavy object from accidentally sliding down.

Although screw jacks can be self-locking, caution is still necessary in practical applications to ensure safety. If you need to support heavy objects for a long time, please use professional support equipment and follow relevant safety operating procedures.