Regarding cycloidal pin wheels

The entire transmission mechanism of planetary cycloidal pinwheel reducers can be divided into three parts: the input section, the reduction section, and the output section. An eccentric sleeve offset by 180° is mounted on the input shaft; two roller bearings known as swivel arms are attached to this eccentric sleeve, forming an H-shaped mechanism. The central holes of the two cycloidal gears serve as the raceways for the bearings on the eccentric sleeve’s swivel arms. The cycloidal gears engage with a set of ring-shaped pin teeth on the pin gear, thereby creating an internal gear reduction mechanism with a tooth difference of one tooth. (To reduce friction, in reducers with a low speed ratio, the pin teeth are equipped with pin tooth sleeves.) When the input shaft rotates one full circle with the eccentric sleeve, due to the characteristics of the tooth profile curve on the cycloid wheel and the restriction imposed by the teeth on the pin gear, the motion of the cycloid wheel becomes a planar motion that involves both revolution and rotation. As the input shaft rotates one full circle in the forward direction, the eccentric sleeve also rotates one full circle; the cycloid wheel then rotates one tooth in the opposite direction, resulting in deceleration. Through the W-output mechanism, the low-speed rotational motion of the cycloid wheel is transmitted to the output shaft via the pin, thereby yielding a lower output speed.

This can be found everywhere; I’m not looking for the principle.