Generally speaking, ordinary planetary gear reducers do not come with self-locking function. The working principle of a planetary gear reducer is that several planetary teeth orbit around the sun gear, and the deceleration process is achieved through the planetary structure. This structure itself does not have self-locking characteristics, that is, without an external power source, the planetary gear reducer cannot automatically lock its output shaft to prevent it from rotating or moving in the opposite direction.
However, some specially designed planetary gear reducers or planetary gearboxes may have self-locking function. This self-locking function is usually achieved by adding additional mechanical structures or components to the planetary gear mechanism, such as clutches, overrunning clutches (one-way bearings), friction components, etc. These components can lock planetary gears or ring gears under specific conditions (such as when the sun gear stops rotating), thereby achieving self-locking effect.
In addition, there are some innovative designs, such as achieving self-locking function of planetary gearboxes through the combination of toothed sliders and slot components. This design can limit the rotation of the output shaft by inserting the toothed slider into the slot element when the gearbox drive device stops driving, thereby achieving self-locking.
It should be noted that the self-locking function of planetary gears is not an inherent characteristic, but requires special design or additional components to achieve. Therefore, when choosing a planetary gear reducer or planetary gearbox, if self-locking function is required, the manufacturer or supplier should be clearly informed and confirmed whether their product has this function.